Effectiveness of the Treatment With Dapagliflozin and Metformin Compared to Metformin Monotherapy for Weight Loss on Diabetic and Prediabetic Patients With Obesity Class III
Phase: PHASE2
Conditions: PreDiabetes, Obesity, Morbid, Diabetes Mellitus, Type 2
Sponsor: Centro Medico Nacional Siglo XXI IMSS

 
 
 
 
 
 
 
 
ID: R-2016-785-094 
Effectiveness of the Treatment With Dapagliflozin and Metformin Compared 
to Metformin Monotherapy for Weight Loss on Diabetic and Prediabetic 
Patients With Obesity Class III 
 
 
NCT03968224 
 
Approval date: 11-Nov-2016 

1. TITLE. 
Efficacy of the treatment with dapagliflozin and metformin compared with metformin monotherapy 
for weight loss and its effects on waist circumference, triacylglycerol concentration, blood 
pressure and inflammatory cytokines on diabetic and prediabetic patients with obesity class III. 
Open, randomized clinical trial. 
 
2. ABSTRACT 
 
Introduction: According to the World Health Organization (WHO), obesity is an abnormal or 
excessive accumulation of fat, which could affect human health. Mexico has one of the highest 
prevalence of obesity, reported by 32.4% of people over 20 years old, according to National 
Health and Nutrition Examination Survey (ENSANUT, Encuesta Nacional de Salud y Nutrición 
2012). This implies that 22 millions of Mexicans have obesity. Additionally, the prevalence of 
obesity class III (defined as a body mass index greater than 40 kg/m2) is 1.8% (IC95% 1.5-2.1%) 
in males and 4.1% (3.7%-4.5%) in females. 
 
The Mexican Social Security Institute (IMSS, Instituto Mexicano del Seguro Social) (that has one 
of the widest health coverages in the country) has reported a prevalence of obesity on its affiliates 
up to 74.4%, but only 50% had received clinical care for weight control (for example, diet or 
physical activity recommendations). In a recent article published by Barrera-Cruz et al. it is 
estimated that this disease reduces life expectancy from 6 to 20 years, being responsible for 2.8 
million deaths per year in our country. In addition, it is estimated that it generates an annual cost 
of 3,500 million dollars for direct and indirect costs. 
 
Since 2008, a multidisciplinary clinic focused on obesity treatment and related comorbidities has 
been organized at the Hospital de Especialidades of Centro Médico Nacional Siglo XXI. Currently, 
the "Obesity Clinic" attends a 400-patient population, of which 150 patients have undergone 
bariatric surgery (gastric bypass or gastric sleeve) and 250 patients are on waiting list and 
preparation for this procedure. According to previous data (not yet published) the mean age of 
these patients is 41 ± 9 years, 46% have pre-diabetes or type 2 diabetes mellitus, 66% has 
hypertension and 33% has dyslipidemia (hypertriglyceridemia, hypoalphalipoproteinemia or 
both). The management of glucose alterations on this unit is done with personalized diets 
supervised by the Nutrition Service of the Obesity Clinic and with the use of metformin at doses 
greater than 2 g/day and/or basal insulin at doses of 0.5 to 1 U/kg of patient's weight. 
 
Recently, a group of drugs known as inhibitors of sodium-glucose transporter protein 2 (iSGLT2) 
has been approved for T2D treatment. These low-affinity and high-capacity transporter proteins 
are found at proximal convoluted tubules and are responsible for glucose re-absorption; therefore, 
its inhibition induces glycosuria and subsequently a decrease of plasmatic glucose. Dapagliflozin 
is a selective iSGLT2 with a sustained effect on the reduction of glycated hemoglobin (HbA1c) at 
0.4 to 0.8%. Additionally, due to the induction of glycosuria up to 20-85 g/day, it has been 
calculated that its use induces a caloric deficit at 80 to 340 kcal/day. This has been observed in 
patients with T2D in which induces a weight loss of 2 to 3 kg and in combination with metformin 
even a weight loss up to 5.07 kg (-6.21 to 3.93 kg) without regain (at least for 2 years) as 

previously demonstrated. Furthermore, it decreases systolic blood pressure (4-5 mmHg), 
increases concentration of HDL cholesterol (1.8 to 4.4%) and decreases triglycerides 
concentration (2.4 to 6.2%). Due its mechanism of action is independent of insulin production; 
there exists a possibility of using dapagliflozin in patients with prediabetes or even on other types 
of diabetes. Regarding safety considerations, main adverse effects related to its use are 
genitourinary infections and it has been demonstrated that it does not induces kidney injury. 
 
A previous study by Bolinder et al. that included 182 patients with T2D inadequately controlled 
with metformin, assessed the effect of dapagliflozin 10 mg in weight loss after 24 weeks of 
treatment and compared it to placebo. They found a decrease of 2.08 kg (2.8 to 1.31 kg, p<0.001), 
decrease in waist circumference of 1.52 cm (2.74 to 0.31, p=0.014), decrease in total fat mass 
assessed with densitometry (DEXA) of 1.48 kg (2.22 to 0.74, p=0.001), decrease of visceral fat 
mass of 258.4 cm3 (448.1 to 68.6, p=0.008) and decrease of subcutaneous fat of 184.9 cm3 (359.7 
to 10.1, p=0.03). However, those studies on weight are performed in patients with obesity class I 
or II and there is a lack of information on inflammatory markers after dapagliflozin treatment. 
 
Primary objective: To determine if combined treatment with dapagliflozin and metformin is more 
effective than monotherapy with metformin for weight loss and assess its effects on waist 
circumference, triglycerides, blood pressure and inflammatory cytokines (resistin, adiponectin, 
interleukin-6 and interleukin-10) in prediabetic and diabetic patients with obesity class III. 
Secondary objective: To determine the effect of combined treatment with dapagliflozin and 
metformin in comparison with monotherapy with metformin on serum concentrations of glucagon, 
ghrelin and insulin. 
 
Patients, material and methods: The protocol includes patients with previous or recently 
diagnosed diabetes or prediabetes from the Obesity Clinic of CMN SXXI from July 2018 to August 
2023 age 18 to 60 years old, both male or female and not treated with insulin. Patients requiring 
initial treatment with insulin, with obesity secondary to other comorbidities and patients who do 
not wish to enter the study or not provide their informed consent will be excluded. Patient’s data 
that during the study are advised to undergo bariatric surgery will be used until the moment of 
surgery. Other treatments will be adequately recorded. Patients will be randomized by computer 
software and assigned in a group treated with metformin (>2 g/day, group 1) or with metformin 
(>2 g/day) and dapagliflozin 10 mg (group 2). All patients will receive dietary treatment and follow- 
up by the Nutrition service during the study. Anthropometric and biochemical variables will be 
recorded at the beginning and at months 3, 6 and 12. Adherence to treatment will be assessed, 
defined by consumption of at least 90% of provided pills. The adverse events will be recorded 
since the beginning of study and will be ranked according to the CTCAE lists (Common 
terminology criteria for adverse events version 4.03). An intention-to-treat analysis will be 
performed in case of patients that require treatment with insulin. 
 
 
3. RATIONALE FOR THE STUDY 

Mexico has one of the highest prevalence of obesity worldwide. According to data from ENSANUT 
2012, 32.4% of people older than 20 years have obesity, which means that 22 millions of 
Mexicans have this pathology. This survey described that 1.8% of male and 4.1% of female 
population have obesity class III. This disease is characterized by an increased risk of 
comorbidities as T2D, atherogenic dyslipidemia, HTN, obstructive sleep apnea hypopnea 
syndrome, as well as an increase in proinflammatory cytokines from adipose tissue, which results 
in a decrease in life expectancy in the economically active population, increased mortality and 
high costs for the healthy system derived from direct or indirect attention. 
 
Since 2008 in the Hospital de Especialidades Centro Médico Nacional Siglo XXI, the 
Endocrinology Department organized an Obesity Clinic with the purpose of generating learning 
strategies of changes in lifestyle, control of comorbidities related with obesity and achieve the 
weight decrease of patients with obesity class III needed to undergo for bariatric surgery. 
However, many patients fail to meet weight reduction despite reporting good adherence to diet 
and exercise strategies. Despite pharmacological treatment is required in these patients, the 
deleterious cardiovascular effects of current treatments contraindicate its use in this population. 
 
At this point, new pharmacological strategies focused on people with obesity class III are required. 
Those strategies need to help in weight decrease and should induce benefits on other 
cardiometabolic parameters such as HTN, increased glucose concentration, hypertriglyceridemia, 
decreased HDL-c and abdominal obesity. 
 
 
4. JUSTIFICATION FOR THE STUDY 
 
Recently, it has been approved for the treatment of T2D, a group of drugs known as inhibitors of 
sodium-glucose co-transporter type 2 (iSGLT2) whose main mechanism of action is the induction 
of glycosuria. Dapagliflozin was the first marketed drug in this class and has a large number of 
studies that have demonstrated its effect on glucose lowering with good safety profile and 
tolerability Furthermore, it has been observed that induces weight loss and also decrease in blood 
pressure, triglycerides, waist circumference by loss of fat mass and increased HDL-c and 
adiponectin concentrations. These effects have been evaluated in patients with T2D with normal 
BMI, overweight and obesity grade I and II but have not been evaluated in patients with class III 
obesity or higher. Furthermore, there is a lack of information about its effects on inflammatory 
cytokine concentrations (resistin, IL-6, IL-10 and TNF-α) or in the glucagon concentration. 
 
Based on previous studies (not yet published), up to 46% of patients at Obesity Clinic have 
prediabetes or diabetes. The use of dapagliflozin in this population could increase weight loss 
and improve other cardiovascular factors. This could be translated into decreased time needed 
to undergo surgical treatment and better control of associated comorbidities. 
 
RESEARCH QUESTION 

What is the efficacy of dapagliflozin and metformin combination in comparison with monotherapy 
with metformin for decrease on weight, waist circumference, triacylglycerol, blood pressure and 
inflammatory cytokines in patients with prediabetes or diabetes and obesity class III? 
 
5. HYPOTHESIS 
 
Dapagliflozin in combination with metformin induce 10% of weight lost and 5% of decrease in 
waist circumference, triacylglycerol concentration, blood pressure and inflammatory cytokines in 
patients with prediabetes or diabetes with class III obesity, in comparison with the 5% of weight 
lost and lack of effect in the rest of parameters in patients treated with metformin monotherapy. 
 
6. OBJECTIVES 
 
a. Primary objective: To determine if combined treatment with dapagliflozin and 
metformin is more effective than monotherapy with metformin for weight loss and 
assess its effects on waist circumference, triglycerides, blood pressure and 
inflammatory cytokines in patients with prediabetes and diabetes with obesity class III. 
b. Secondary objectives: 
i. 
To determine efficacy of metformin monotherapy for 
weight loss and decrease on waist circumference, triglycerides and 
blood pressure in patients with prediabetes and diabetes with 
obesity class III. 
ii. 
To compare efficacy of metformin monotherapy and 
combined treatment with metformin and dapagliflozin. 
iii. 
To determine the percentage of patients that with 
combined treatment achieves a decrease in total weight of 5%, 10% 
and 15% and the percentage of patients that achieve a decrease in 
10% of excess weight. 
iv. 
To  evaluate  if  combined  treatment  allows  a 
decrease in number of drugs needed for comorbidities’ control. 
v. 
To 
evaluate prevalence 
of 
adverse effects 
commonly associated with dapagliflozin use (urinary and genital 
tract infections, hydroelectrolytic alterations) in patients with obesity 
class III. 
vi. 
To determine serum concentration of adiponectin, 
resistin, IL-6, IL-10 and TNF-α before and after treatments, and 
compare it between groups. 
viii. 
To determine serum concentration of insulin, 
glucagon and ghrelin before and after treatments, and compare it 
between groups. 

7. BACKGROUND 
 
Definition and classification of obesity 
 
According to the World Health Organization (WHO), obesity is defined as an abnormal or 
excessive fat accumulation that impairs health. Recently, clinical guidelines developed by the 
Mexican Social Security Institute (IMSS, Instituto Mexicano del Seguro Social) defined it as a 
multi-causal, chronic and systemic disease that involves individuals from different ethnic groups, 
independently of age or social class [1]. 
 
Obesity is classified according to body mass index (BMI), defined as a person’s weight in 
kilograms (kg) divided by the square of its height in meters (m). Current WHO classification 
defines overweight as a BMI of 25 to 29.9 kg/m2, obesity class I with a BMI of 30 to 34.9 kg/m2, 
obesity class II with a BMI of 35 to 39.9 kg/m2 and extreme obesity or class III with a BMI above 
40 kg/m2 [2]. However, there are some patients with BMI greater than those ranges, with different 
clinical characteristics and worst cardiovascular outcomes. In this way the term "super-obesity" 
was coined to define patients with BMI greater than 50 kg/m2 [3]and later the term "super-super 
obese" emerged to define those patients with a BMI greater than 60 kg/m2 [4]. 
 
In Mexico obesity is defined using WHO criteria, however, according Mexican Official Standard 
NOM-008-SSA-2010 published by Department of Health, overweight must be defined as a BMI 
between 23 to 25 kg/m2 and obesity with a BMI higher than 25 kg/m2 in male with a height lesser 
than 1.60 m or females with a height lesser than 1.50 m [5]. 
 
Epidemiology 
 
Mexico has one of the higher prevalence of overweight and obesity worldwide. According to the 
National Health and Nutrition Survey 2012 (ENSANUT 2012), 38.8% of Mexicans over 20 years 
were overweight and 32.4% had obesity, with a prevalence of 26.9% in male and 37.5% in female 
population. This implies that almost 22 millions of Mexicans had some grade of obesity around 
the country. This survey also showed that higher prevalence of obesity is reported in population 
from 40 to 49 years old (40.5%), higher prevalence of obesity class III is found among people 
from 50 to 59 years old (14.3%) and this prevalence increases in locations with a higher socio - 
economic level (28.5%), urban areas (28.5%) and in the north side of the country (29.4%). 
Additionally, it was reported a prevalence of obesity class III in male of 1.8% (CI95% 1.5-2.1%) 
and in females of 4.1% (CI95% 3.7-4.5%). However, this survey did not identify individuals with a 
BMI higher than 40 kg/m2 [6]. 
 
Obesity is related with 2.8 million deaths per year around the world. It is estimated that obese 
persons died 8 to 10 years earlier that those with normal weight and that every 15 kg above ideal 
weight increases the risk of early death by 30% [7]. Furthermore, it has been found that mortality 
due to cardiovascular diseases increases up to 50% in patients with obesity and up to 90% in 
patients with extreme obesity, in comparison with people with normal weight [8]. In fact, in United 
States it is estimated that obesity is responsible of 300,000 deaths per year [9]. Mexico lacks 

statistics about number of deaths per year attributed to obesity; however in 2012 the National 
Institute of Geography and Informatics (INEGI) reported 109,309 deaths caused by 
cardiovascular diseases of which 74,057 deaths were due to myocardial infarction; 85,055 deaths 
were related to diabetes and 31,905 deaths were caused by stroke. All of those diseases are 
related to obesity [10]. 
 
Obesity Clinic of the Centro Medico Nacional Siglo XXI, IMSS 
 
The Mexican Social Security Institute (IMSS) has the broader coverage of health of the country. 
According to ENSANUT 2012, 74.4% of its beneficiaries are obese and it is estimated that only 
50% receive medical attention focused on weight control (e.g. diet or physical activity 
recommendations). Considering the current increase in the prevalence of obesity and an 
imperious need of reducing the prevalence of co-morbidities and high mortality rate associated 
with this disease, since 2008 the Hospital de Especialidades from the Centro Medico Nacional 
Siglo XXI organized a multidisciplinary team composed by members from departments of 
Endocrinology, Clinical Nutrition, Bariatric Surgery, Psychiatry and Internal Medicine, under the 
name of "Obesity Clinic". 
 
The requirements for admission are a BMI greater than 35 kg/m2 with a major comorbidity 
(diabetes, hypertension, dyslipidemia or sleep apnea syndrome) or obesity class III. Patients are 
initially evaluated by nutritionists authorized to assess anthropometric measures, who also adjust 
diet based on weight and initial consumption of calories and evaluate patients monthly recording 
weight, waist and hip circumference, percentage of adherence to diet and amount of physical 
exercise per week (measured in minutes per week). At the same time, the endocrinologists 
perform clinical assessment and laboratory tests for detection and control of comorbidities such 
as altered metabolism of glucose (Type 2 diabetes [T2D] or pre-diabetes), hypertension (HTN) 
and dyslipidemia and request assessment and treatment of other specialists if necessary. 
Meanwhile, psychiatrists perform tests for detection and treatment of anxiety disorders or 
depression, eating disorders, personality disorders and other psychiatric comorbidities that could 
influence negatively on the management of patients and finally, once the patients lost 10% of 
excess of weight, they become candidates for bariatric surgery (laparoscopic Roux-Y bypass or 
gastric sleeve, depending on the evaluation of surgeons). 
 
Several studies support that weight reduction before surgery decreases surgical risk and 
improves time to recovery. It has been observed that patients with super-obesity have a higher 
incidence of complications during bariatric surgery associated with increased technical difficulties 
(for example an increased liver volume due to steatosis), increased anesthetic risk and risk of 
treatment failure. 
 
Santo et al. in 2014 conducted a prospective study for evaluating possible benefits related to pre- 
surgical weight decrease in patients with super-obesity. In this study, 20 patients had in-hospital 
strict dietary control with diets between 600 and 1500 kcal plus aerobic physical activity (in those 
allowed to do it). Patients obtained a reduction of 19.7% of initial weight, with decrease of BMI 

from 67 kg/m2 to 55 kg/m2 over a 24-weeks period. In this group, they observed a lower incidence 
of complications and decreased time of hospitalization [11]. 
 
Prevalence of comorbidities in the Obesity Clinic 
 
The Obesity Clinic evaluates a population of approximately 400 patients, 150 patients have 
undergone bariatric surgery, 250 patients are pending of approval for such proceedings and up 
to 10 new patients per month are assessed for determine its possible admission to the clinic. 
 
Sanchez-Ruiz et al. previously performed a retrospective study with a sample of 109 patients from 
the Obesity Clinic who underwent bariatric surgery between January 2009 and December 2011 
(in press). In this study, the mean age was 45.3 ± 10.1 years, 70% were female, 85% reported 
attachment to diet (up to 80%), 31% performed physical activity (defined as at least 30 minutes 
of daily walking), 21% were smokers, 74% had a family history of obesity and 67% reported 
overweight or obesity since childhood. In this study, we observed that 46% of patients had 
prediabetes (defined by the American Diabetes Association, [ADA] as a plasmatic fasting level 
greater than 100 mg/dl and less than 126 mg/dl or a 2-h plasma glucose level measured after a 
75-g oral glucose load, greater than 140 mg/dl and less than 200 mg/dl) or T2D (defined as fasting 
glucose greater than 126 mg/dl or a glucose level post-load greater than 200 mg/dl) [12], 66% 
had HTN and 33% had dyslipidemia (hypertriglyceridemia, hypoalphalipoproteinemia, or both). At 
this clinic, patients with prediabetes or T2D are usually treated with metformin 2 g/day or Neutral 
Protamine Hagedorn insulin (NPH) with calculated doses of 0.5 to 1 U/kg of weight when 
necessary and are evaluated every three months for treatment adjustment depending on their 
glycated hemoglobin as stipulated by ADA guidelines [12]. 
 
Pharmacological treatment of obesity 
 
According to 2015 clinical practice guidelines of the Endocrine Society co-sponsored by the 
Obesity Society and the European Society of Endocrinology, pharmacologic treatment is justified 
for weight loss in those individuals with BMI > 30 kg/m2 or BMI> 27 kg/m2 with comorbidities (TD2, 
hypertension, dyslipidemia), in addition to diet and exercise, with doses according to patient 
characteristics and tolerance for the drug. They also recommend suspension and change of 
treatment if patients do not decrease at least 5% of initial weight after 12 weeks [13]. Current 
weight loss drugs authorized by the Food and Drug Administration (FDA) and European 
Medicines Agency (EMA) are: 
a) Orlistat. Approved since 1999, this drug inhibits pancreatic lipase, enzyme responsible 
for the degradation of triacylglycerols in mono and diacylglycerols for their absorption 
in the intestine. It induces fat excretion through feces (30% of triacylglycerols ingested) 
but had a modest effect on weight: a 60 mg dose is associated with a decrease of -2.5 
kg (CI95% -1.5 to -3.5 kg) and 120 mg is associated with reduction of -3.4 kg (IC95% 
-3.2 to -3.6 kg). Furthermore, due its mechanism of action, it reduces cyclosporine and 
levothyroxine concentrations, has been associated with decrease on fat-soluble 
vitamins and is contraindicated in patients with gastrointestinal diseases, chronic renal 
failure (CRF) and those in risk of cholelithiasis. Finally, it has a poor rate of adherence 

due to its adverse effects (steatorrhea and urgency to defecation), being 40% 
approximately [14]. 
b) Phentermine/topiramate. Phentermine is a sympathomimetic amine with anorexigenic 
effect at central level (acting directly on the secretion of pro-opiomelanocortin [POMC], 
hormone responsible of satiety from paraventricular nucleus of hypothalamus). 
Topiramate is a monosaccharide that acts like an agonist of gamma aminobutyric acid 
(GABA) receptor and antagonist of calcium channels, with anorexigenic action [15]. 
The combination of phentermine 7.5 mg with extended-release topiramate 46 mg and 
15/92 mg was assessed in the CONQUER study, a randomized, double-blind, 
placebo-compared study with follow-up of 56 weeks performed at 93 centers in the 
United States [16]. This study found that the combination of diet, exercise and a dose 
of 7.5/46 mg (n = 488 patients) achieved a decrease of 5% of initial weight in 62% of 
the population and decrease of 10% of initial weight in 37% of the population 
meanwhile a dose of 15/92 mg (n = 981) achieved a decrease of 5% of initial weight 
in 70% of the population and decrease of 10% of initial weight in 48% of the population 
in comparison to placebo (21% decreased 5% and 7% decreased 10% of initial weight, 
n = 979), with p <0.001 for all determinations. They also found a significant decrease 
in waist circumference, systolic and diastolic blood pressure, total cholesterol, LDL- 
cholesterol, triacylglycerols and glycated hemoglobin in patients that used both 
combinations with greater differences at higher doses. The effects of this drug were 
confirmed by the SEQUEL study, which consisted in monitoring patients from the 
CONQUER study for 108 weeks [17]. Adverse effects observed in both studies were 
dry mouth, paresthesia, constipation, dysgeusia, insomnia, dizziness, anxiety, 
irritability and impaired attention. It is noteworthy that this study only contemplates 
patients with BMI of 27-45 kg/m2 [16, 17]. 
c) Naltrexone/bupropion. Naltrexone is a non-selective opioid antagonist originally used 
to treat opiate addiction and for the treatment of alcohol withdrawal syndrome. Their 
main mechanism of action for weight reduction lies in inhibiting the μ receptor from 
hypothalamic neurons that secrete POMC, thereby decreasing the self-inhibitor effect 
generated by co-secretion of β-endorphins generated by POMC cleavage. Bupropion 
is an anorexigenic amine that directly induces POMC secretion [14]. The combination 
of naltrexone 32 mg with bupropion 360 mg was tested in four randomized, double- 
blind, compared with placebo, phase III clinical trials for 56 weeks: COR-I which 
included 1742 patients, COR-II that included 1496 patients from the previous study, 
COR-BMOD that evaluated 793 patients with intensive lifestyle modification and COR- 
DM that included patients with T2D [18]. Those studies found that treatment with 
naltrexone/bupropion allowed that 53% to 80% of patients achieved a decrease of 5% 
of initial weight and 26% to 55% of patients achieved a decrease of 10% (p <0.001). 
However, due to common adverse effects of nausea, constipation, vomiting, diarrhea, 
headache, dizziness, insomnia and upper airways symptoms [19], only 50 to 54% of 
patients completed proposed treatment [18]. 
d) Lorcaserin. It is a 5-hydroxytryptamine 2c receptor agonist that stimulates 
hypothalamic POMC secretion. In a previous clinical trial, randomized and compared 
with placebo, 1538 patients were assigned to lorcaserin 10 mg for 104 days. After this 

time, 47.5% of patients achieved a reduction of 5% of initial weight and 22.6% a 
decrease of 10% compared to 20.3% and 7.7% achieved with placebo, p <0.001. 
Additionally, a significant reduction in waist circumference, systolic and diastolic blood 
pressure, cholesterol, triglycerides and HbA1c was observed [20]. Main adverse 
effects reported were headache, upper airways infections, nasopharyngitis, dizziness, 
nausea and sinusitis [20]. 
e) Glucagon-like peptide type 1 receptor agonists (GLP-1). Initially they were used for 
the treatment of T2D due to its mechanism of action, based on the incretin effect that 
induce insulin secretion and decrease glucagon secretion [21]. Additionally, it was 
observed that they slow gastric emptying and intestinal motility thereby increasing the 
feeling of gastric fullness; had a direct anorexigenic effect through GLP1 receptors in 
hypothalamus; and increase the activity of the sympathetic nervous system, thereby 
generating increased lipolysis and insulin secretion [22]. A recent clinical trial, 
controlled, randomized, double-blinded, compared with placebo (n = 1225) assessed 
subcutaneous administration of liraglutide 3.0 mg in 2437 patients without T2D. It was 
observed that after 56 weeks of treatment, 63.2% of patients decreased 5% of the 
initial weight, 33.1% decreased 10% of initial weight and 14.4% decreased 15% of the 
initial weight (compared to placebo which decreased 27.1%, 10.6% and 3.5%, 
respectively; p <0.001) [23]. Furthermore, it was observed a decrease in waist 
circumference, HbA1c, triacylglycerols and systolic and diastolic blood pressure [23]. 
Main adverse effects included nausea, diarrhea or constipation, vomiting, dyspepsia 
and nasopharyngitis. This clinical trial (SCALE) also included Mexican patients; minor 
effects were observed in patients with BMI greater than 40 kg/m2. 
 
Mexico's COFEPRIS has approved only orlistat and, more recently, liraglutide for obesity 
treatment. 
 
Sodium-glucose co-transporter 2 inhibitors (iSGLT2) 
 
In 1835 a phenolic glycoside called phlorizin was isolated from the bark of the apple tree. Initially, 
it was used for research on electrolytes and glucose transport at the kidney. This compound was 
initially tested in animals, where it induced glycosuria and weight loss independently of glycaemia, 
and later it was also observed in humans [24]. However, until 50’s it was discovered that this 
compound blocks the facilitated glucose transport in erythrocytes and inhibits glucose transport 
in the kidneys and small intestine, and at early 90's it was characterized that such transportation 
was mediated by sodium-glucose co-transporter type 2 (SGLT-2) at the kidney. 
 
Families of glucose transporters 
 
There are three families of glucose transporters in the human genome: the SLC2 family of 
facilitated transporters, also known as GLUTs; the SLC5 family of "active glucose transporters" 
characterized by transport against the concentration gradient, and the SLC50 family of uniporters 
(SWEET) [25]. 

Nowadays there are 13 members of GLUT family identified [26], being the most common: GLUT1, 
an insulin-independent transporter expressed in erythrocytes, endothelial cells and brain; GLUT2, 
transporter at pancreatic β cell with a fundamental role for insulin secretion; GLUT3, transporter 
at neuronal tissue, responsible for glucose transference to cerebrospinal fluid; GLUT4, widely 
spread in muscle and adipose tissue and GLUT5, a fructose transporter located in enterocytes at 
small intestine [27]. 
 
Meanwhile, there are 12 human genes identified in family SCL5, which are expressed in different 
tissues as small intestine, kidneys, brain, muscle and thyroid gland. One of the most important is 
SLC5A1, expressed in 22q12.3, encodes SGLT1, a transporter located in the small intestine, 
trachea, kidneys, heart, brain, testis and prostate. SGLT1 is a high affinity but low-capacity 
transporter with little renal effect and their main substrates are glucose and galactose. SLC5A2 
gene is expressed in 16p11.2 and encodes SGLT-2, a low affinity but high-capacity transporter 
located in kidneys, heart, liver, heart muscle and salivary glands [24, 25]. Other transporters are 
SGLT-3 encoded by SLC5A4 in 22q12.3, located in the small intestine, skeletal muscle, kidney, 
uterus and testis; SGLT4 encoded by SLC5A9 in 1p33, located in kidney, intestine, brain, heart, 
lung and uterus and SGLT5 encoded by SLC5A10 in 17p11.2, located only in renal cortex [25]. 
 
At kidney, SGLT2 is responsible of 90% of glucose reabsorption and it’s located at apical domain 
of epithelial cells in the proximal tubule (S1 segment) meanwhile remaining 10% is reabsorbed 
by SGLT1 at the end of the proximal tubule (S3 segment) [24]. 
 
SGLT2 inhibitors (iSGLT2): Dapagliflozin 
 
Once discovered, there was an attempt to use phlorizin in humans; however, this compound has 
poor oral bioavailability and is rapidly inactivated in the intestine to its inactive metabolite aglycone 
phloretin. Pharmacological tests further led to the synthesis of compounds such as T-1095, a 
methylated compound that is converted to its active metabolite in the liver and has high affinity 
and selectivity for human SGLT2. At initial evaluation, it was observed that this compound 
improved HbA1c levels, glucose and triglyceride levels and improved insulin sensitivity, with 
beneficial effects on weight gain [28, 29]. Subsequently, other glycosides derived from phlorizin 
were synthesized: 29, 45 and 46, sergliflozine and finally dapagliflozin [24]. 
 
First studies using dapagliflozin in rats, observed an induced glycosuria without hypoglycemia 
[30]; subsequently Komoroski et al. evaluated the dose of 5 mg, 25 mg and 100 mg in 47 patient’s 
natives to treatment or with current treatment with metformin (monotherapy) for 14 days (with 
baseline HbA1c of 6 to 10%). In these patients they found that dapagliflozin 5, 25 and 100 mg 
induced glycosuria of 40, 73 and 82 g/day, respectively. At the end of the study, they observed a 
rate of urinary glucose excretion of 35, 68 and 66 g/day and improvement in plasma glucose 
concentrations and glucose tolerance [31]. At the same time, two randomized, double-blinded 
clinical trials assessed the use of sergliflozine in non-diabetic overweight or obese patients. In 
this group they also found elevation in GLP-1 concentration and a decrease of weight of 1.5 kg 
compared to placebo. This was the first study that proposed a possible effect on weight [32]. 

Dapagliflozin in T2D 
 
Clinical guidelines for treatment of diabetes recommend metformin as first-choice drug for patients 
with HbA1c below 9% [12]. However, in patients with drug intolerance, an iSGLT2 could be used 
as monotherapy. A previous study with dapagliflozin 10 mg for 12 weeks, observed a decrease 
in HbA1c of -0.12% (CI95% -0.41 to 0.17%), like that produced by metformin [33]. In studies using 
dapagliflozin as second-line treatment (patients treated with metformin), there has been a 
decrease in HbA1c of -0.30% (CI95% -0.51 to -0.09%) compared to glipizide (sulfonylurea) [34]. 
Similarly, in patients previously treated with pioglitazone (a thiazolidinedione), addition of 
dapagliflozin induced a decrease in HbA1c of -0.67% (95% CI -0.88 to -0.46% compared to 
placebo) [35]. Furthermore, in patients previously treated with sulfonylureas as first-line treatment, 
addition of dapagliflozin had a similar glycemic effect to GLP-1 (difference in HbA1c of 0.11% with 
95%CI -0.18 to 0.4%) [36]. Finally, it has been used as third-line treatment in patients with 
maximum doses of metformin and sitagliptin. In this group, addition of dapagliflozin reduced 
HbA1c by 0.6% (95%CI -0.8 to -0.4%) [37]. 
 
Because of their mechanism of action independent of the functionality of the β cell it has been 
proposed that this drug can be used in patients with type 1 diabetes or prediabetes [38]. 
 
Dapagliflozin and α and β cell function 
 
It has been observed that use of dapagliflozin improves β cell function, as assessed using 
homeostatic valuation models of β cell (HOMA-β). It is believed that this protective effect is due 
to decrease in glucose, thereby decreasing the glucotoxicity phenomenon [38]. However, Bonner 
et al. recently found that alpha cells express SGLT1 and SGLT2 and proposed that this inhibition 
induces glucagon secretion [39]. This theory is supported by observation that some patients with 
T2D increase hepatic glucose production and serum levels of glucagon [40]. This effect may 
attenuate improvement on plasma glucose concentrations relative to glycosuria induced by 
dapagliflozin without counteracting its effect [40]. 
 
Dapagliflozin and blood pressure 
 
It has been observed that use of dapagliflozin induces a decrease in blood pressure from 12 
weeks of use, comparable to hydrochlorothiazide [41]. A recent meta-analysis reported that the 
use of dapagliflozin decreased systolic blood pressure by -3.78 mmHg (95%CI -4.49 to -3.07 
mmHg) and diastolic blood pressure by -1.41 mmHg (95% CI -1.8 to -0.96 mmHg) [42]. The 
effects on blood pressure have been associated with the induction of osmotic diuresis in 
association with a decrease in weight; however, it has also been suggested that increased release 
of sodium at juxtaglomerular level and therefore affects renin-angiotensin-aldosterone system 
[38]. 
 
Dapagliflozin and dyslipidemia 

Some clinical trials have reported moderate effects on total cholesterol and HDL cholesterol. In a 
phase III study conducted in patients with metformin at doses higher than 1500 mg/day with 
inadequate glycemic control, dapagliflozin increased HDL-c in 1.8% to 4.4% and decreased 
triacylglycerols in -2.4 -6.2%, compared to placebo. Another study at 52 weeks in patients using 
metformin and sulfonylureas showed that canagliflozin (other iSGLT-2) increased levels of HDL- 
C by 7.6% (95% CI 4.6 to 9.3%); however, this study also observed an increase in LDL-C 
concentrations of 11.7% (95% CI 1.7 to 11.2%), with no changes on atherogenic index [43]. 
 
Weight loss associated with metformin 
 
Metformin is the main member of the biguanide drug class and is widely used in T2D treatment, 
estimated that 150 million people worldwide use it. However, although it has been marketed since 
1957, its precise mechanism of action is not fully understood. Its proposed mechanism is that is 
internalized in the hepatocyte through the organic anion transporter (OCT), it accumulates in the 
mitochondria and inhibits complex I, which decreases ATP and raises AMP, generating activation 
of cAMP kinase (AMPk) [44]. This enzyme inhibits transcription of genes involved in 
gluconeogenesis and inhibits lipogenesis via phosphorylation of acetyl-CoA carboxylase, 
inhibition of the transcriptional activity of sterol regulatory element-binding protein (SREBP-1) and 
carbohydrate-responsive element binding protein (ChREBP). However, there are AMPk 
independent mechanisms as well as antineoplastic, aging-related and intestinal microbiota 
regulatory mechanisms [45]. 
 
Different studies have reported a modest decrease in weight or stability compared with other 
hypoglycemic medications [46]. Hermann et al. were the first to describe the body weight effects 
of metformin [47]. In 1991 they studied 25 patients with a mean age of 59 years (range 36-69 
years) with an average weight of 76.4 kg (63-97 kg) for women and 77.4 kg (64.5-92 kg) for men 
previously treated with glyburide. In this group, they observed a decrease of -2.64 kg of total 
weight (95% CI -4.23 to -1.05 kg) after one year of treatment. Subsequently Stumvoll et al. 
conducted a study with 10 patients with T2D (6 men and 4 women), aged 58 ± 9 years and 
average BMI of 32.1 ± 3.2 kg/m2 to those treated with initial doses of metformin 850 mg increments 
every two weeks to 2550 mg (850 mg three times a day) [48]. After 16 weeks observed a total 
weight loss of -2.7 ± 1.3 kg (95.1 ± 14.9 vs. initial 92.4 ± 14.5 kg end, p <0.001) and -2.4 ± 2.2 kg 
of fat mass, determined by bioimpedance (initial 31.2 ± 11.4 vs. 28.9 ± 10.1 kg end, p = 0.02) 
(48). That same year, DeFronzo et al. conducted a study to compare the metabolic effects of 
metformin, glyburide, and the combination of both. In that study the group with metformin (n=210 
patients, average age 55 ± 1 years, mean BMI 29.4 ± 0.3 kg/m2) reported a loss of -3.8 ± 0.2 kg, 
compared with less weight loss observed in the group with glyburide or the weight gain observed 
in the group with combination therapy for 29 weeks [49]. 
 
Moreover, Mogul et al. conducted a retrospective analysis of 30 non-diabetic women who 
previously tried to lose weight with diet and exercise and grouped them into two categories of 
BMI: 25 to 32.9 kg/m2 (group 1) and 33 to 41.7 kg/m2 (group 2). In addition to a hypocaloric diet, 
they received a dose of 1500 mg and 2000 mg metformin, respectively. In group 1, a loss of 3.47 
kg (SE, standard error 0.68), 6.41 kg (0.72) and 8.06 kg (0.96) at 3, 6 and 12 months of treatment 

was observed and in group 2 a weight loss of 4.4 kg (0.8), 9.7 kg (2.3) 15.1 (3.3) kg was observed 
at those times. In this study, 96% of patients achieved a loss of more than 5% of body weight at 
6 months and 81% lost more than 10% of weight at 12 months [50]. 
 
Weight loss associated with dapagliflozin 
 
Obesity is generated by an increase in caloric intake associated with deficit of caloric expenditure. 
Dapagliflozin induces glycosuria of 20 to 85 g/day in humans and 0.5 to 1.9 g/day in rats (weighing 
200 g), which means that would generate a caloric deficit of 80-340 kcal/day in humans and 2 to 
7.6 kcal/day in rats. Assuming a consumption of 6.16 kcal/g of fat in rodents and 3,500 kcal/lb of 
fat in humans, the use of dapagliflozin theoretically induces a weigh loss of 0.32 to 1.2 g/day in 
rats and 0.022-0.097 lb/day (9.97 43.9 g/day) in humans [51]. 
 
As monotherapy, dapagliflozin has shown to be as effective as metformin in terms of weight 
decrease (-1%, 95%CI -2.04 to 0.04%) [33]. In association with metformin, dapagliflozin induced 
a loss of -5.07 kg (95%CI -6.21 to -3.93 kg) compared to glipizide [34]. When used in combination 
with pioglitazone for 48 weeks, a loss of -2.3 kg (95%CI -3.37 to -1.23 kg) was observed in 
comparison to placebo [35] and when used in patients previously treated with sulfonylurea 
induced a loss of -1.54 kg (95%CI -2.16 to -0.92 kg) compared with the group with GLP-1 (loss - 
0.65 kg, 95%CI -1.37 to 0.07 kg) and DPP4 inhibitor (gain of 0.57 kg, 95%CI 0.09 to 1.06 kg) [36]. 
Finally, even in the metformin and sitagliptin group, the addition of dapagliflozin induced a loss of 
-2.1 kg (95%CI -3.2 to -1 kg) compared to placebo [37]. 
 
According to this data, Zhang et al. proposed that urinary glucose excretion of 71.2 g/24 h should 
decrease 3.05 kg. However, only 2.5 kg was achieved (20% less than expected) [52]. This led to 
Devenny et al. to evaluate possible compensatory mechanisms that attenuate the effect of 
dapagliflozin. In a group of rats with obesity induced by diet (DIO), dapagliflozin was orally 
administered in doses of 0.5 mg/kg, 1 mg/kg and 5 mg/kg, inducing a weight and fat mass loss in 
a dose-dependent (greater in the 5 mg/kg). In their study, the effect on weight and fat mass was 
greater in those animals with restricted food consumption (4 times more weight loss for 10 days 
of treatment). However, in the group of animals with diet ad libitum, they observed an increase in 
appetite since day 7 in animals with 0.5 mg/kg and since day 10 in rats with 0.1 mg/kg. This 
increase in appetite was maintained throughout the study. Other changes measured were the 
increase in water consumption, increased rate of respiratory turnover (especially in the group with 
dietary restrictions), increased concentration of beta-hydroxybutyrate (ketone body) and 
decreased insulin and non-esterified fatty acids (NEFA) concentration. This study proposed: 1) 
the effect of dapagliflozin on weight can be altered by an increase in appetite, 2) due to the 
increase in the rate of respiratory exchange ratio, associated with a decrease on NEFA and 
increase of ketone bodies, the weight decrease could be associated with increased lipolysis as a 
metabolic attempt to maintain energy balance and 3) decreasing insulin levels may be associated 
with a decrease on insulin resistance [51]. The effect on appetite has not been evaluated in 
humans. Furthermore, the quantification of appetite is complicated, so it is proposed to determine 
ghrelin concentration, a hormone synthesized by the stomach that modulate brain activity in the 

areas that control appetite [53]. However, there are currently no studies on the effect of 
dapagliflozin on the ghrelin concentration. 
 
 
In a previous study, Bolinder et al. included 182 patients with type 2 diabetes inadequately 
controlled with metformin (mean HbA1c 7.17%) and evaluated the effect of dapagliflozin 10 mg 
on total weight after 24 weeks in comparison to placebo. This group found decrease on weight by 
2.08 kg (2.8 to 1.31 kg, p <0.001), waist circumference in 1.52 cm (2.74 to 0.31 cm, p = 0.014), 
total fat mass assessed by densitometry (DEXA) in 1.48 kg (2.22 to 0.74, p = 0.001), visceral fat 
mass in 258.4 cm3 (448.1 to 68.6, p = 0.008) and subcutaneous fat mass in 184.9 cm3 (359.7 to 
10.1 , p = 0.03) [54]. 
 
It is noteworthy that all studies have been conducted in patients with BMI under 40 kg/m 2, so its 
effect on weight and other metabolic factors has not been studied in populations with extreme 
obesity. 
 
Dapagliflozin and inflammatory markers 
 
The term meta-inflammation is used to describe chronic, low-grade inflammation caused by 
obesity and it is associated with an increased cardiovascular risk [55]. Adipose tissue is an 
endocrine organ formed by adipocytes and stromal tissue containing precursors of adipocytes, 
nerves, vessels and cells of the immune system and together can produce adipokines (cytokines), 
growth factors and proteins [56-60]. It was observed that adipose tissue of patients with obesity 
have increased the production of leptin, visfatin, vaspin, apelin, retinol binding protein 4 (RPB-4), 
resistin and lipocalin 2 (cytokines and proinflammatory proteins), and decrease the production of 
adiponectin, fatty acid-binding protein type 4 (FABP-4) and perilipin (cytokines and anti- 
inflammatory proteins) [56, 59-64]. Furthermore, it has been observed an increased number of 
macrophages in this tissue, that also form corona structures and polarize from type 2 to type 1, 
with a subsequent increased secretion of cytokines and proinflammatory proteins as interleukin- 
6 (IL-6), interleukin 1B (IL-1B), tumor necrosis factor alpha (TNF-α), hepatocyte growth factor 
(HGF), inhibitor of plasminogen activator-1 (PAI-1), C-reactive protein (CRP), interleukin-18 (IL- 
18), monocyte chemoattractant protein-1 (MCP-1), vascular endothelial growth factor (VEGF-1) 
and decreased secretion of anti-inflammatory cytokine: interleukin 10 ( IL-10) [59-68]. It has been 
observed that weight decrease and specifically the decrease in abdominal fat, decreases meta- 
inflammation defined by the presence of high concentrations of CRP, IL-6, TNF-α, resistin and 
diminished levels of IL-10 and adiponectin, especially when patients decrease more than 10% of 
their body weight [59-68]. 
 
There is only one article where the effect of dapagliflozin on the concentration of inflammatory 
cytokines was evaluated. Okamoto et al. observed the effect of 5 mg of dapagliflozin administered 
for 12 weeks, in highly sensitive CRP (hs-CRP), adiponectin and PAI-1. This study included 27 
Japanese patients, 63% male (n = 17), aged 49.7 ± 8.8 years and BMI of 32.7 ± 6.5 kg/m2 and a 
significant decrease in the concentrations of hs-CRP (2410 ± 2814 ng/ml at baseline vs. 1607 ± 
1960 ng/ml at the end of 12 weeks, p <0.01), and increased adiponectin levels (5.1 ± 2.3 mg/ml 

vs. 6.7 ± 4.2 mg/ml, p <0.01) was observed. No significant changes were observed in the 
concentrations of PAI-1 (30 ± 16.8 mg/ml to 26.8 mg/ml, p = 0.07). Furthermore, they found an 
inverse correlation between changes in HbA1c/body weight changes and adiponectin (ρ = -0.787 
and -0.696, respectively, p <0.05) and positive correlations of such parameters with changes in 
PAI-1 (ρ = 0.382 and 0.435, respectively, p <0.05) [69]. Finally, the authors evaluated the effect 
of dapagliflozin (comparison between before and after administration) on concentrations of 
glucagon and insulin in 11 patients before and after a test meal tolerance, finding a significant 
increase in glucagon before test (p <0.01), after an hour (p = 0.02) and after two hours (p <0.01) 
post-test and a significant decrease in the post-test insulin after an hour (p = 0.04) [69]. 
 
According to the effect of decreased weight and waist circumference previously reported in 
patients with obesity grade I and II who are given dapagliflozin, we expected a decrease of 
concentrations like resistin, IL-6 and TNF-α and an increase of concentrations of IL-10 and 
adiponectin. 
 
Adiponectin 
It is also known as adipoQ, Acrp30 (Adipocyte Complement Related Protein) or apM1. It’s a 
protein exclusively secreted by adipose tissue, with a serum concentration of 5 to 10 mg/ml (10 
to 30 nM). It has been observed that its concentration is reduced in obese and diabetic mice and 
humans. Subsequently it was found that hypoadiponectinemia is present before insulin resistance 
and the return to adequate concentrations decreased this resistance in animal models. In addition 
to its role as insulin sensitizer, it has anti-inflammatory and anti-apoptotic properties [70-72]. 
 
Resistin 
It’s a protein discovered by Steppan et al., which is encoded on chromosome 19 and leads the 
family of resistin-like molecules (RELMs). There has been observed an increase in concentration 
of patients with type 2 diabetes and patients with obesity. Although their functions are not fully 
understood, it has been observed to cause insulin resistance in the liver and has a possible role 
as regulator of the immune system [70, 72]. 
 
Interleukin 6 (IL-6) 
IL-6 was characterized as a pro-inflammatory cytokine secreted by adipose tissue. It has been 
linked with the downregulation of IRS-1 (insulin receptor substrate type 1), impaired 
phosphorylation of tyrosine kinase, and decreased expression of GLUT4 (glucose transporter 4). 
Additionally, it increases resistance and decreases adiponectin levels [73-75]. 
 
Interleukin 10 (IL-10) 
It is also known as Cytokine-synthesis Inhibiting Factor (CSIF). IL-10 is a cytokine with anti- 
inflammatory properties due to their ability to inhibit the synthesis of pro-inflammatory cytokines 
from T-lymphocytes and macrophages. Its presence has been proven in human atherosclerotic 
plaques and it has been that its low concentration favors the development of larger and unstable 
atherosclerotic lesions [76]. 
 
Tumor necrosis factor alpha (TNF-α) 

Initially, TNF-α was described as a pro-inflammatory cytokine released by macrophages and 
monocytes as part of the immune response. Soon after, its expression and release were 
discovered in adipocytes and was quickly linked to insulin resistance in rodents and humans with 
obesity. It is known that TNF-α is involved in several processes related with development of insulin 
resistance, such as [77-79]: 
1) 
Reduces expression of GLUT4, consequently decreasing glucose caption in the cell. 
2) 
Induces serine phosphorylation at insulin receptor, affecting signaling cascades. 
3) 
Induces down-regulation of IRS-1. 
4) 
Increases expression of IL-6 and leptin and decreases adiponectin expression. 
5) 
It has been associated with adipocytes apoptosis through increased concentration 
of intra-cellular free fatty acids. 
 
Security of dapagliflozin 
 
Based on combined analysis of three clinical trials, it was observed that dapagliflozin did not 
cause hypoglycemia compared to other oral hypoglycemic drugs (OR 0.49, 95%CI 0.18 to 1.39). 
In fact, hypoglycemia rate was 10 times lower compared with sulfonylureas. 
 
The most common side effect observed in patients treated with dapagliflozin is genital tract 
infection (OR 3.48, 95%CI 2.33 to 5.20): vulvar-vaginal mycotic infections in women and balanitis 
in men, none of whom was reported as serious or requiring treatment discontinuation. It was also 
observed an increase in the incidence of urinary tract infections (OR 1.43, 95%CI 1.05 to 1.94), 
which were reported as mild to moderate intensity, were more frequent in females and caused a 
low rate of discontinuation (0.3% vs. 0.1% with placebo) [80]. 
 
There have been some cases of breast cancer in patients treated with dapagliflozin; however, 
diagnosis was made since day 6 to 334 of use (9 of 5501 patients), so it is unlikely that 
dapagliflozin could be involved due to the short exposure time. In this way, it has been reported 
to have an incidence of 0.17% of bladder cancer (10 of 6045 patients). This could be associated 
with a lack of scrutiny prior to inclusion in the study [41]. 
 
Additionally, its use is not recommended for patients with chronic kidney disease (CKD) or in 
those with glomerular filtration rate (GFR) <60 ml/min/1.73 m2 due to loss of effectiveness and a 
possible increased risk of fractures in this population. It’s also not recommended in people at risk 
of inadvertent volume depletion (like patients over 65 years with renal impairment or using loop 
diuretics) [41]. 
 
Diabetic ketoacidosis in patients using iSGLT2 
 
Recently the FDA issued a warning statement of a possible association between the use of 
iSGLT2 with a type of diabetic ketoacidosis, characterized by minimal to moderate glycemic 
elevation, named as “euglycemic diabetic ketoacidosis” [81]. This warning was based on 20 cases 
reported between March 2013 and June 2014, most patients had type 1 diabetes (T1D), other 
comorbidities, had decreased food and liquid intake or a history of alcohol consumption [82]. 

Subsequently, EMA announced that until May 2015, 101 cases of diabetic ketoacidosis in patients 
with T2D have been reported. However, until September 2015, information came from case 
reports and any clinical trials that clearly explain the frequency of this association had been 
performed [81]. 
 
Erondu et al. from Janssen Company informed that in CANVAS study (CANAGLIFLOZIN 
Cardiovascular Assessment Study) until May 2015, there have been 15 cases of diabetic 
ketoacidosis associated with canagliflozin from 17,596 participants (incidence rate of 0.5, 0.8 and 
0.2 per 1,000 patients/year for canagliflozin at 100 mg, 300 mg and comparator, respectively) 
[83]. Meanwhile, AstraZeneca Company has reported a frequency of 0.1% of possible events 
related to dapagliflozin from DECLARE’s study (Dapagliflozin Effect on Cardiovascular Events) 
and Boehringer has reported the same incidence in the study EMPA-REG that includes 7,000 
patients in treatment with empagliflozine [81]. From these data, canagliflozin is the drug most 
associated with ketoacidosis, however up to 50% of the reported cases are patients with T1D, in 
whom the use of iSGLT2 is not authorized. 
 
Regarding euglycemic ketoacidosis’ pathophysiological mechanism, it has been observed that 
iSGLT2 induced glycosuria up to 85 g/day by 24 hours and therefore in a 60 year old patient with 
overweight (BMI 28 kg/m2) and in a diet with 50% of carbohydrates, this glycosuria should cause 
a loss of 17 to 34% of carbohydrates consumed in men and 22 to 44 % in women [84]. These 
drugs induce insulin release and decrease of glucagon routinely, but in those patients with a strict 
glucose control, the persistent action of iSGLT2 could decrease insulin release due to a decrease 
in glucose (main effector). This hormonal change releases the inhibition of gluconeogenesis in 
the liver causing moderate fasting and postprandial hyperglycemia (glucose remain being 
eliminated by the kidneys), and subsequently stimulates lipolysis with an increase on serum free 
fatty acids (up to 40%) and lipid oxidation (up to 20%) [85]. Free fatty acids released are 
transported to the liver where β-oxidation increases with formation of ketone bodies. Finally, 
iSGLT2 also induces volume depletion, which aggravates that condition. Furthermore, it seems 
that reported cases were associated with special conditions where patients decreased insulin 
doses due to iSGLT2 effect on serum glucose, but there were increased requirements (such as 
stress, infections or use of alcohol). 
 
Further studies are needed to determine conclusively if ketoacidosis depends on type of drug 
used (which in turn depends on variability of the inhibition’s degree of SGLT2 between drugs) and 
if their existence restricts the widespread use of these drugs. 
 
8. PATIENTS, MATERIAL AND METHODS 
Type of study: Phase II/III, controlled, randomized, open clinical trial. 
By study groups: two parallel groups’ design. 
By maneuvering: experimental 
By measurements in the population: longitudinal 
By temporality: prospective 
By the nature of the study: clinical 
By purpose: Therapeutic 

Study Population 
· 
Patients with obesity class III from the "Obesity Clinic” in preparation for bariatric 
surgery. 
· 
Study period: December 2016 to October 2018 
· 
Place of study: Mexico City, Mexico 
· 
Time of clinical assessment of each patient: one year 
 
Workplan 
1) A convenience sampling will be done for patients diagnosed with diabetes or 
prediabetes according to ADA criteria [12] (Appendix 1), who come to Obesity Clinic 
in the indicated period and that meet the selection criteria. Since the first assessment, 
patients are informed that they would become candidate for bariatric surgery (bypass 
or gastric sleeve, depending on surgeons’ criteria) once they achieve a weight 
reduction of 10%. 
2) Due patients achieve weight loss needed for the surgical procedure at different times 
of follow-up (3, 6 or 12 months), clinical, biochemical, and initial and final 
determinations of inflammatory cytokines and hormones, will be collected until the 
previous valuation before surgery. Data will be collected even if the patients require 
treatment with sulfonylureas or insulin (adverse event grade 3). 
3) Prevalence of comorbidities at baseline and the type and dose of drugs used for 
treatment will be recorded (Appendix 2. Data Collection Sheet). Treating physicians 
based on the clinical response of patients, will decide the dose and number of drugs 
and will record changes in the corresponding data sheet. 
4) Patients will be randomized by a random numbers system generated with a 
computational software and will be assigned to a group: 1) metformin (2 g/day) or 2) 
metformin (2 g/day) and dapagliflozin 10 mg. All patients will receive dietary treatment 
and follow-up during the study by Nutrition service. Dietary treatment is individualized, 
as it is based on the initial weight of the patient and their eating habits at the time of 
valuation. It is expected that dietary treatment does not influence the results because 
all patients will undergo diet and those with little attachment (defined as failure to 
comply with at least 80% of the prescribed diet) are discharged of the surgical protocol. 
The Nutrition service calculates the percentage of adherence to diet. 
5) Once assigned to the corresponding group, patients will receive an identification code 
that will be retained throughout the study. One of the researchers not directly involved 
in patient care, will assign tablets needed for daily intake for a month and then the 
number of tablets required for 3 months in a sealed envelope. 
6) A run-in period will be used to assess tolerance to treatments. This period will be for a 
month. At this time patients will be advised of a possible increase on uresis and will 
be instructed in the relevance of increasing fluid intake. 
7) The anthropometrical and biochemical variables will be recorded at baseline and at 1, 
3, 6 and 12 months (Appendix 2. Data Collection Sheet). A clinical nutritionist 
accredited as Level 1 Anthropometrist by the International Society for the 
Advancement of Kinanthropometry (ISAK) will assess the weight on a scale with a 

maximum capacity of 300 kg and precision of 100 g; height using an stadimeter, and 
waist circumference using a fiberglass tape, according to the manual of procedures 
for nutrition projects of the Centro de Investigación en Nutrición y Salud de Instituto 
Nacional de Salud Pública [86], and also in accordance with the procedures manual 
for the assessment of clinical and anthropometrical measurements in the adult and 
elderly of the Ministry of Health [87] (Appendix 3. Clinical and anthropometric 
measurements). 
8) The determination of blood pressure will be performed by a nurse from the Obesity 
Clinic, using an aneroid sphygmomanometer, recording the average of two 
measurements taken with a 5-minutes difference, according to the procedure’s manual 
for the assessment of clinical and anthropometrical measurements in the adult and 
elderly of the Ministry of Health (Appendix 3. takes clinical and anthropometric 
measurements). 
9) The determination of insulin, glucagon, ghrelin, adiponectin, resistin, IL-6, IL-10 and 
TNF-α will be held at baseline and before surgery (depending on the response of each 
patient). For the determination of these cytokines and peptides, an ELISA kit (enzyme 
linked immunosorbent assay) will be used (Appendix 4. ELISA technique). 
10) Adherence to treatment will be evaluated and will consist in consumption of 90% of 
pills granted. The registration of adverse events will take place from the start of 
treatment and throughout the study. Each event will be evaluated by researchers and 
classified according to CTCAE list (Common terminology criteria for adverse events 
version 4.03). CTCAE considers that an adverse event grade 4 or 5 indicates 
discontinuation of treatment; grade 3 must be submitted to review by the medical team, 
and grades 1 or 2 require registration and intervention but not discontinuation of 
treatment (Appendix 5. CTCAE list). Adverse events will be recorded in the report 
sheet (Appendix 6. Sheet report for drug side effects). 
11)  The patients that do not achieve weight loss at one-year follow-up will be discarded 
to their primary care hospital as pre-specified by the Obesity Clinic internal regulation. 
 
Selection criteria 
Inclusion criteria 
1. Age from 18 to 60 years 
2. Any gender 
3. BMI greater than or equal to 40 kg/m2 
4. Diagnosis of diabetes or prediabetes according to the criteria of the ADA. Patients 
must have glycated hemoglobin less than 9%. 
5. Patients who sign informed consent letter (Appendix 7. Charter informed consent) 
6. Candidates to bariatric surgery 
 
Exclusion criteria 
1. Current use of insulin or sulfonylureas 
2. Chronic kidney disease with glomerular filtration rate <60 ml/min/1.73 m2 
3. Use of loop diuretics with no possibility to suspend. 

4. Concomitant illnesses that predispose to volume depletion, weight loss (including 
oncological diseases), or metabolic acidosis (including drug users) 
5. History of recurrent genital or urinary tract infections 
6. Use of drugs for weight control. 
7. Untreated or uncontrolled hypothyroidism (defined through TSH higher than 4.2 μU/ml) 
8. Pregnant or lactating mother. 
9. Tobacco use (in the last month) 
10. Current use of steroids or nonsteroidal anti-inflammatory drugs 
 
 
Withdrawal criteria 
1. Becoming pregnant during the study 
2. Tobacco use 
3. Use of steroids during the study 
 
Sample size 
Weight loss after dapagliflozin treatment has not been previously used as primary outcome in 
randomized controlled trials (RCT) of patients with prediabetes or diabetes and grade III obesity. 
Zhang et al. performed a meta-analysis that included seven RCTs evaluating the effect of 
metformin combined with SGLT2-inhibitors (dapagliflozin 10 mg/day, canagliflozin 300 mg/day, 
empagliflozin 25 mg/day, or ipragliflozin 300 mg/day) vs. metformin (at doses of 1.5 to 3 g/day) 
with placebo on HbA1c; fasting plasma glucose; and body weight over 24 weeks, 1 year, and 2 
years. The total sample was 2847 patients with a mean BMI of 31.7 ± 4.9 kg/m2. After a year of 
treatment, the placebo–metformin control group showed a reduction in body weight of 1.1 ± 3.39 
kg, whereas the SGLT-2 inhibitor–metformin group showed a 3.6 ± 4.22 kg reduction with a mean 
difference of− 2.6kg (− 3.17 to− 2.03 kg), p < 0.0000. Using these data, we calculated a sample 
size using a mean difference formula. With a power of 80% (alpha level of 0.05) in a two-sided T- 
test, the sample size required is 90 patients: 45 patients in the M group and 45 patients in the 
D/M group. The final sample size required is 108 patients: 54 patients in metformin and 54 patients 
in the dapagliflozin group, allowing for a 20% dropout rate. 
Variable definition 
 
Variable 
name 
Variable Type 
Scale 
Conceptua 
l definition 
Operational definition 
Units 
INDEPENDENT VARIABLES 

Type of treatment Qualitat 
ive, 
dichoto 
mic 
Nominal Metformin 
is 
a 
biguanide 
with effect 
in 
cyclic 
AMP 
kinase that 
diminishes 
insulin 
resistance. 
Diabetes 
treatment 
guidelines 
consider it 
as the first 
line 
therapy. 
Dapagliflozi 
n 
is 
an 
SGLT2 
inhibitor 
that 
induces 
glycosuria 
and 
has 
been 
approved 
for 
monothera 
py 
 in 
patients 
with 
metformin 
intolerance 
and also as 
a second or 
third 
line 
therapy for 
diabetes. 
Use of metformin 2 grams 
per day or use of metformin 
2 
grams 
per 
day 
in 
combination with 10 mg of 
dapagliflozin. 
0 = metformin, 
1 
= 
metformin/dap 
agliflozin 
DEMOGRAPHIC VARIABLES 
Age 
Quantit 
ative, 
continu 
ous 
Ratio 
Time 
elapsed 
from birth to 
Time elapsed from birth to 
the baseline registry of the 
patient. 
years 

the current 
date. 
Gender 
Qualitat 
ive, 
dichoto 
mic 
Nominal Taxon that 
gathers 
members 
of the same 
species. 
Gender assigned in the 
registry documents. 
0 = female 
1 = male 
Height 
Quantit 
ative, 
continu 
ous 
Ratio 
Length of a 
human 
body when 
measured 
in 
a 
standing 
position 
from the top 
of head to 
the floor. 
Height registered in the 
baseline documents using 
the same stadiometer in all 
patients during the first 
evaluation. 
meters (m) 
Body mass index Quantit Ratio 
Measurem Ratio between weight in kg/m2 
(BMI) 
ative 
ent 
that kilograms (kg) divided by 
continu 
associates the square of the height in 
ous 
height  and meters. 
Calculation 
is 
size in the performed in every clinical 
same 
evaluation 
during 
the 
individual 
protocol. 
and 
classifies 
them 
as 
underweigh 
t, 
normal, 
overweight 
or obese. 
DEPENDENT VARIABLES 
Weight 
Quantit Ratio 
The 
force Total amount of kilograms kilograms (kg) 
ative 
that 
registered  in  the  same 
continu 
gravitation 
person using the same 
ous 
exerts upon calibrated 
scale 
at 
a body. 
baseline and months 3, 6 
and 12. 

Waist 
circumference 
(WC) 
Quantit 
ative 
continu 
ous 
Ratio 
Measurem 
ent of the 
body 
circumfere 
nce 
measured 
at 
the 
minimum 
circumfere 
nce 
between 
the 
iliac 
crest 
and 
the 
rib 
cage. 
Perimeter registered in 
the documents using the 
same flexible tape at 
baseline and months 3, 6 
and 12. 
centimeters 
(cm) 
Fasting Glucose 
Quantit 
ative 
continu 
ous 
Ratio 
Glucose 
concentrati 
on in the 
blood 
serum after 
an 8 hour 
fast. 
Blood glucose reported at 
baseline, months 3,6 and 
12. 
mg/dl 
Fasting Insulin 
Quantit 
ative 
continu 
ous 
Ratio 
Insulin 
concentrati 
on in the 
patients 
serum 
determined 
by 
radioimmu 
noassay 
after an 8 
hour fast. 
Blood insulin reported at 
baseline and months 3,6 
and 12. 
mU/L 
HOMA-IR 
Quantit 
ative 
continu 
ous 
Ratio 
The 
homeostati 
c 
 model 
assessmen 
t (HOMA) is 
a 
method 
used  
to 
quantify 
insulin 
resistance 
and 
beta- 
HOMA 
= 
[glucose 
(mg/dl)/18 
*insulin 
(mU/L)]/22.5 at baseline 
and months 3,6 and 12. 
Dimensionless 

cell 
function. 
Glycated 
hemoglobin 
(HbA1c) 
Quantit 
ative 
continu 
ous 
Ratio 
Is the most 
abundant 
of the minor 
component 
s 
in 
hemoglobin 
, formed by 
the 
condensati 
on 
of 
glucose  in 
the 
N- 
terminal 
portion   of 
the 
beta 
chain of the 
hemoglobin 
molecule, 
representin 
g 
 an 
average of 
blood 
glucose 
concentrati 
on for the 
last 
three 
months. 
Percentage of glycated 
hemoglobin in the blood of 
patients at baseline and 
months 3,6 and 12, using 
immunoanalysis 
with 
turbidimetric inhibition. 
% 
Cholesterol 
Quantit 
ative 
continu 
ous 
Ratio 
Total 
cholesterol 
in 
the 
serum 
of 
the patient 
after an 8- 
12   hour 
fast. 
Magnitude 
obtained 
in 
lipid profile of patients at 
baseline and months 3,6 
and 12 after an 8-12 hour 
fast. 
mg/dl 

Triglycerides 
Quantit 
ative 
continu 
ous 
Ratio 
Triglyceride 
concentrati 
on in the 
serum 
of 
the patient. 
Magnitude 
obtained 
in 
lipid profile of patients at 
baseline and months 3,6 
and 12 after an 8-12 hour 
fast. 
mg/dl 
c-HDL 
Quantit 
ative 
continu 
ous 
Ratio 
High- 
density 
cholesterol 
concentrati 
on in the 
serum 
 of 
the patient. 
Magnitude 
obtained 
in 
lipid profile of patients at 
baseline and months 3,6 
and 12 after an 8-12 hour 
fast. 
mg/dl 
c-LDL 
Quantit 
ative 
continu 
ous 
Ratio 
Low- 
density 
cholesterol 
concentrati 
on in  the 
serum 
 of 
the patient 
calculated 
using 
the 
Friedwald 
formula. 
c-LDL = total cholesterol– 
(c-HDL + triglycerides/5) 
at baseline and months 
3,6 and 12 after an 8-12 
hour fast. 
mg/dl 
Systolic 
and 
diastolic 
blood 
pressure 
Qualitat 
ive 
nominal 
Nominal 
Dichoto 
mic 
Measurem 
ent of the 
pressure of 
the 
blood 
against the 
inner walls 
of the blood 
vessels. 
Blood 
pressure 
determined by the same 
investigator 
in 
two 
different 
measurements 
after 30 minutes of resting 
in 
a 
sitting 
position, 
performed 
5 
minutes 
apart from each other. 
mmHg 
Adiponectin 
Quantit 
ative 
continu 
ous 
Ratio 
Protein 
secreted 
exclusively 
by 
the 
adipose 
tissue and 
directly 
related 
to 
Concentration determined 
using the method ELISA. 
pg/ml 

insulin 
resistance. 
Resistin 
Quantit 
ative 
continu 
ous 
Ratio 
Protein, 
member of 
the 
RELM 
family, 
related 
to 
insulin 
resistance 
in the liver 
tissue. 
Concentration determined 
by 
using 
the 
method 
ELISA. 
ng/ml 
Interleukine 6 (IL- 
6) 
Quantit 
ative 
continu 
ous 
Ratio 
Pro- 
inflammato 
ry cytokine, 
secreted by 
adipose 
tissue and 
related   to 
insulin 
resistance 
mediated 
by 
 the 
insulin 
receptor. 
Concentration determined 
using the method ELISA. 
pg/ml 
Interleukine 
10 
(IL-10) 
Quantit 
ative 
continu 
ous 
Ratio 
Anti- 
inflammato 
ry cytokine 
related 
 to 
the 
developme 
nt 
of 
atheroscler 
osis 
Concentration determined 
using the method ELISA. 
pg/ml 
Ghrelin 
Quantit 
ative 
continu 
ous 
Ratio 
Hormone 
secreted in 
the gastric 
fundus that 
induces 
appetite. 
Concentration determined 
using the method ELISA. 
pg/ml 

Glucagon 
Quantit 
ative 
continu 
ous 
Ratio 
Hormone 
produced 
by 
pancreatic 
alpha cells 
that 
counteracts 
the  effects 
of insulin. 
Concentration determined 
using the method ELISA. 
ng/ml 
 
Statistical analysis: Quantitative variables were described using measures of central tendency 
and dispersion according to the data distributions. Qualitative variables were described using 
frequencies or percentages. The Shapiro-Wilk test was used to establish normality in the 
distribution of quantitative variables. Because information on the different quantitative variables 
was available up to different time periods, a mixed model analysis was performed using the 
restricted maximum likelihood (REML) method, as well as a mixed model considering the fixed 
effects of assigned treatment, sex, and prediabetes or diabetes status, and the random effects of 
variability in weight loss over time. Comparisons between groups were analyzed using Sidak's 
post-hoc test. Pearson's chi-square test or Fisher's exact test were used to evaluate the 
association between qualitative variables. Statistical significance was defined as a p < 0.05. Data 
analysis was performed using SPSS version 17.0 and STATA version 11.0. 
 
4. ETHICAL ISSUES 
 
For the realization of this protocol, we will apply for approval by the Instituto Mexicano del Seguro 
Social (IMSS) National Ethics Committee. The proposed procedures are compliant with ethical 
regulations, the General Health Law regarding Health Research, the institutional regulations for 
investigation, the declaration of Helsinki in 1975 and its amendments. It also is compliant with the 
currently approved international codes and norms regarding Good Clinical Practice in Clinical 
Investigation. 
Risk: according to the General Health Law regarding Health Research, this study represents a 
“higher than minimum risk” for the participants since it is a clinical trial (Article 17). 
Contributions and benefits of the study for the participants and society: patients will not be 
directly benefited from this study. This statement will be stipulated into informed consent form. 
Regarding utility of the study, in case that we can determine higher effectiveness of the 
combination of metformin with dapagliflozin in terms of weight control, glucose concentrations, 
blood pressure and triglycerides, we will be able to recommend its inclusion in the treatment for 
the metabolic control of patients with extreme obesity. 
Confidentiality: Patient will be guaranteed that personal data will be kept confidential according 
to the Article 21 Fraction VIII of the General Health Law regarding Investigation Research. 
Conditions under which the informed consent will be requested: The informed consent form 
will be requested before the inclusion of the patient in the study. The patients will be invited 
personally when they attend to their regular visits to the outpatient clinic. (See appendix 7. 
Informed Consent Form). The principal investigator and co-investigators will sign the consent. 

The patient will be explained about the freedom to withdraw consent at any time during the 
investigation according to Article 21 Fraction I-VII of the General Health Law regarding 
Investigation Research. 
Participant selection: all patients meeting the inclusion criteria and no exclusion criteria that 
sign informed consent will be included in the study. 
 
11. RESOURCES AND ENVIRONMENT 
Human resources. All the investigators participating in this study have expertise in clinical trials, 
they are trained in the management of the patients attending to the clinic and they are authorized 
to perform and handle blood samples and patient data. 
The investigator group includes one attending physician registered in the obesity clinic in the 
Endocrinology department, which will also be in charge of this protocol as part of the work to 
achieve his Doctors degree in Science (D.Sc.); other members of the group are two attending 
general endocrinologists with experience in clinical investigation in obesity and two other 
endocrinologists from the Experimental Endocrinology Unit which constitutes the laboratory area 
of the Endocrinology department. These endocrinologists can perform the laboratory techniques 
required for this protocol and one of them has been previously involved in protocols with 
pharmaceutical companies. 
Material resources. The investigation unit and the endocrinology department have the necessary 
equipment required for the procedures. We will apply for financing for the purchase of the ELISA 
kits as well as for some of the supplies required for the protocol. 
Feasibility. According to the large number of patients existing in the Obesity Clinic that are waiting 
for bariatric surgery and the frequency of metabolic disturbances found in the extremely obese, 
we consider that the number of patients required for the study is feasible. 
The clinical and laboratory investigators involved in this protocol have the necessary expertise for 
the management of patients with extreme obesity, taking blood samples and information 
gathering. The Investigation Unit has ample experience in the management of biological samples 
and analysis with ELISA. They have also performed studies in the field of immunoendocrinology. 
 
10. REFERENCES 
1. 
Barrera-Cruz A, Avila-Jimenez L, Cano-Perez E, Molina-Ayala MA, Parrilla-Ortiz 
JI, Ramos-Hernandez RI, Sosa-Caballero A, Sosa-Ruiz Mdel R, Gutierrez-Aguilar 
J: Guía de práctica clínica: Prevención, diagnóstico y tratamiento del 
sobrepeso y la obesidad exógena. Revista medica del Instituto Mexicano del 
Seguro Social 2013, 51(3):344-357. 
2. 
Obesity: preventing and managing the global epidemic. Report of a WHO 
consultation. World Health Organization technical report series 2000, 894:i-xii, 1- 
253. 
3. 
Mason EE, Doherty C, Maher JW, Scott DH, Rodriguez EM, Blommers TJ: Super 
obesity and gastric reduction procedures. Gastroenterology clinics of North 
America 1987, 16(3):495-502. 
4. 
Nguyen NT, Ho HS, Palmer LS, Wolfe BM: Laparoscopic Roux-en-Y gastric 
bypass for super/super obesity. Obesity surgery 1999, 9(4):403-406. 

5. 
NORMA Oficial Mexicana NOM-008-SSA3-2010, Para el tratamiento integral 
del sobrepeso y la obesidad. In. Edited by Gobernación Sd. Diario Oficial de la 
Federación; 2010. 
6. 
Barquera S, Campos-Nonato I, Hernandez-Barrera L, Pedroza A, Rivera- 
Dommarco JA: Prevalencia de obesidad en adultos mexicanos, ENSANUT 
2012. Salud publica de Mexico 2013, 55 Suppl 2:S151-160. 
7. 
Barrera-Cruz A, Rodriguez-Gonzalez A, Molina-Ayala MA: Escenario actual de 
la obesidad en México. Revista medica del Instituto Mexicano del Seguro Social 
2013, 51(3):292-299. 
8. 
Mechanick JI, Kushner RF, Sugerman HJ, Gonzalez-Campoy JM, Collazo-Clavell 
ML, Guven S, Spitz AF, Apovian CM, Livingston EH, Brolin R et al: American 
Association of Clinical Endocrinologists, The Obesity Society, and American 
Society for Metabolic & Bariatric Surgery Medical Guidelines for Clinical 
Practice for the perioperative nutritional, metabolic, and nonsurgical support 
of the bariatric surgery patient. Surgery for obesity and related diseases : official 
journal of the American Society for Bariatric Surgery 2008, 4(5 Suppl):S109-184. 
9. 
Rizzello M, De Angelis F, Campanile FC, Silecchia G: Effect of gastrointestinal 
surgical manipulation on metabolic syndrome: a focus on metabolic surgery. 
Gastroenterology research and practice 2012, 2012:670418. 
10. 
Causas de mortalidad en la población general 
11. 
Santo MA, Riccioppo D, Pajecki D, Cleva R, Kawamoto F, Cecconello I: 
Preoperative weight loss in super-obese patients: study of the rate of weight 
loss and its effects on surgical morbidity. Clinics (Sao Paulo) 2014, 69(12):828- 
834. 
12. 
Standards of medical care in diabetes-2015 abridged for primary care 
providers. Clinical diabetes : a publication of the American Diabetes Association 
2015, 33(2):97-111. 
13. 
Apovian CM, Aronne LJ, Bessesen DH, McDonnell ME, Murad MH, Pagotto U, 
Ryan DH, Still CD: Pharmacological management of obesity: an endocrine 
Society clinical practice guideline. The Journal of clinical endocrinology and 
metabolism 2015, 100(2):342-362. 
14. 
Yanovski SZ, Yanovski JA: Long-term drug treatment for obesity: a systematic 
and clinical review. Jama 2014, 311(1):74-86. 
15. 
Cosentino G, Conrad AO, Uwaifo GI: Phentermine and topiramate for the 
management of obesity: a review. Drug design, development and therapy 2013, 
7:267-278. 
16. 
Gadde KM, Allison DB, Ryan DH, Peterson CA, Troupin B, Schwiers ML, Day WW: 
Effects of low-dose, controlled-release, phentermine plus topiramate 
combination on weight and associated comorbidities in overweight and 
obese adults (CONQUER): a randomised, placebo-controlled, phase 3 trial. 
Lancet 2011, 377(9774):1341-1352. 
17. 
Garvey WT, Ryan DH, Look M, Gadde KM, Allison DB, Peterson CA, Schwiers M, 
Day WW, Bowden CH: Two-year sustained weight loss and metabolic benefits 
with controlled-release phentermine/topiramate in obese and overweight 

adults (SEQUEL): a randomized, placebo-controlled, phase 3 extension 
study. The American journal of clinical nutrition 2012, 95(2):297-308. 
18. 
Billes SK, Sinnayah P, Cowley MA: Naltrexone/bupropion for obesity: an 
investigational 
combination 
pharmacotherapy 
for 
weight 
loss. 
Pharmacological research 2014, 84:1-11. 
19. 
Hollander P, Gupta AK, Plodkowski R, Greenway F, Bays H, Burns C, Klassen P, 
Fujioka K: Effects of naltrexone sustained-release/bupropion sustained- 
release combination therapy on body weight and glycemic parameters in 
overweight and obese patients with type 2 diabetes. Diabetes care 2013, 
36(12):4022-4029. 
20. 
Smith SR, Weissman NJ, Anderson CM, Sanchez M, Chuang E, Stubbe S, Bays 
H, Shanahan WR: Multicenter, placebo-controlled trial of lorcaserin for weight 
management. The New England journal of medicine 2010, 363(3):245-256. 
21. 
Pi-Sunyer X: Liraglutide in Weight Management. The New England journal of 
medicine 2015, 373(18):1781-1782. 
22. 
Secher A, Jelsing J, Baquero AF, Hecksher-Sorensen J, Cowley MA, Dalboge LS, 
Hansen G, Grove KL, Pyke C, Raun K et al: The arcuate nucleus mediates GLP- 
1 receptor agonist liraglutide-dependent weight loss. The Journal of clinical 
investigation 2014, 124(10):4473-4488. 
23. 
Pi-Sunyer X, Astrup A, Fujioka K, Greenway F, Halpern A, Krempf M, Lau DC, le 
Roux CW, Violante Ortiz R, Jensen CB et al: A Randomized, Controlled Trial of 
3.0 mg of Liraglutide in Weight Management. The New England journal of 
medicine 2015, 373(1):11-22. 
24. 
Idris I, Donnelly R: Sodium-glucose co-transporter-2 inhibitors: an emerging 
new class of oral antidiabetic drug. Diabetes, obesity & metabolism 2009, 
11(2):79-88. 
25. 
Wright EM: Glucose transport families SLC5 and SLC50. Molecular aspects of 
medicine 2013, 34(2-3):183-196. 
26. 
Shepherd PR, Kahn BB: Glucose transporters and insulin action--implications 
for insulin resistance and diabetes mellitus. The New England journal of 
medicine 1999, 341(4):248-257. 
27. 
Wood IS, Trayhurn P: Glucose transporters (GLUT and SGLT): expanded 
families of sugar transport proteins. The British journal of nutrition 2003, 
89(1):3-9. 
28. 
Oku A, Ueta K, Arakawa K, Ishihara T, Nawano M, Kuronuma Y, Matsumoto M, 
Saito A, Tsujihara K, Anai M et al: T-1095, an inhibitor of renal Na+-glucose 
cotransporters, may provide a novel approach to treating diabetes. Diabetes 
1999, 48(9):1794-1800. 
29. 
Ueta K, Ishihara T, Matsumoto Y, Oku A, Nawano M, Fujita T, Saito A, Arakawa 
K: Long-term treatment with the Na+-glucose cotransporter inhibitor T-1095 
causes sustained improvement in hyperglycemia and prevents diabetic 
neuropathy in Goto-Kakizaki Rats. Life sciences 2005, 76(23):2655-2668. 
30. 
Meng W, Ellsworth BA, Nirschl AA, McCann PJ, Patel M, Girotra RN, Wu G, Sher 
PM, Morrison EP, Biller SA et al: Discovery of dapagliflozin: a potent, selective 

renal sodium-dependent glucose cotransporter 2 (SGLT2) inhibitor for the 
treatment of type 2 diabetes. Journal of medicinal chemistry 2008, 51(5):1145- 
1149. 
31. 
Komoroski B, Vachharajani N, Boulton D, Kornhauser D, Geraldes M, Li L, Pfister 
M: Dapagliflozin, a novel SGLT2 inhibitor, induces dose-dependent 
glucosuria in healthy subjects. Clinical pharmacology and therapeutics 2009, 
85(5):520-526. 
32. 
Hussey EK, Dobbins RL, Stoltz RR, Stockman NL, O'Connor-Semmes RL, Kapur 
A, Murray SC, Layko D, Nunez DJ: Multiple-dose pharmacokinetics and 
pharmacodynamics of sergliflozin etabonate, a novel inhibitor of glucose 
reabsorption, in healthy overweight and obese subjects: a randomized 
double-blind study. Journal of clinical pharmacology 2010, 50(6):636-646. 
33. 
List JF, Woo V, Morales E, Tang W, Fiedorek FT: Sodium-glucose cotransport 
inhibition with dapagliflozin in type 2 diabetes. Diabetes care 2009, 32(4):650- 
657. 
34. 
Nauck MA, Del Prato S, Duran-Garcia S, Rohwedder K, Langkilde AM, Sugg J, 
Parikh SJ: Durability of glycaemic efficacy over 2 years with dapagliflozin 
versus glipizide as add-on therapies in patients whose type 2 diabetes 
mellitus is inadequately controlled with metformin. Diabetes, obesity & 
metabolism 2014, 16(11):1111-1120. 
35. 
Rosenstock J, Vico M, Wei L, Salsali A, List JF: Effects of dapagliflozin, an 
SGLT2 inhibitor, on HbA(1c), body weight, and hypoglycemia risk in patients 
with type 2 diabetes inadequately controlled on pioglitazone monotherapy. 
Diabetes care 2012, 35(7):1473-1478. 
36. 
Orme M, Fenici P, Lomon ID, Wygant G, Townsend R, Roudaut M: A systematic 
review and mixed-treatment comparison of dapagliflozin with existing anti- 
diabetes treatments for those with type 2 diabetes mellitus inadequately 
controlled by sulfonylurea monotherapy. Diabetology & metabolic syndrome 
2014, 6:73. 
37. 
Jabbour SA, Hardy E, Sugg J, Parikh S: Dapagliflozin is effective as add-on 
therapy to sitagliptin with or without metformin: a 24-week, multicenter, 
randomized, double-blind, placebo-controlled study. Diabetes care 2014, 
37(3):740-750. 
38. 
Fioretto P, Giaccari A, Sesti G: Efficacy and safety of dapagliflozin, a sodium 
glucose 
cotransporter 
2 
(SGLT2) 
inhibitor, 
in 
diabetes 
mellitus. 
Cardiovascular diabetology 2015, 14(1):142. 
39. 
Bonner C, Kerr-Conte J, Gmyr V, Queniat G, Moerman E, Thevenet J, Beaucamps 
C, Delalleau N, Popescu I, Malaisse WJ et al: Inhibition of the glucose 
transporter SGLT2 with dapagliflozin in pancreatic alpha cells triggers 
glucagon secretion. Nature medicine 2015, 21(5):512-517. 
40. 
Hattersley AT, Thorens B: Type 2 Diabetes, SGLT2 Inhibitors, and Glucose 
Secretion. The New England journal of medicine 2015, 373(10):974-976. 

41. 
Liakos A, Karagiannis T, Bekiari E, Boura P, Tsapas A: Update on long-term 
efficacy and safety of dapagliflozin in patients with type 2 diabetes mellitus. 
Therapeutic advances in endocrinology and metabolism 2015, 6(2):61-67. 
42. 
Baker WL, Smyth LR, Riche DM, Bourret EM, Chamberlin KW, White WB: Effects 
of sodium-glucose co-transporter 2 inhibitors on blood pressure: a 
systematic review and meta-analysis. Journal of the American Society of 
Hypertension : JASH 2014, 8(4):262-275 e269. 
43. 
Jayawardene D, Ward GM, O'Neal DN, Theverkalam G, MacIsaac AI, MacIsaac 
RJ: New treatments for type 2 diabetes: cardiovascular protection beyond 
glucose lowering? Heart, lung & circulation 2014, 23(11):997-1008. 
44. 
Hundal RS, Krssak M, Dufour S, Laurent D, Lebon V, Chandramouli V, Inzucchi 
SE, Schumann WC, Petersen KF, Landau BR et al: Mechanism by which 
metformin reduces glucose production in type 2 diabetes. Diabetes 2000, 
49(12):2063-2069. 
45. 
Pryor R, Cabreiro F: Repurposing metformin: an old drug with new tricks in 
its binding pockets. The Biochemical journal 2015, 471(3):307-322. 
46. 
Goodarzi MO, Bryer-Ash M: Metformin revisited: re-evaluation of its properties 
and role in the pharmacopoeia of modern antidiabetic agents. Diabetes, 
obesity & metabolism 2005, 7(6):654-665. 
47. 
Hermann LS, Karlsson JE, Sjostrand A: Prospective comparative study in 
NIDDM patients of metformin and glibenclamide with special reference to 
lipid profiles. European journal of clinical pharmacology 1991, 41(3):263-265. 
48. 
Stumvoll M, Nurjhan N, Perriello G, Dailey G, Gerich JE: Metabolic effects of 
metformin in non-insulin-dependent diabetes mellitus. The New England 
journal of medicine 1995, 333(9):550-554. 
49. 
DeFronzo RA, Goodman AM: Efficacy of metformin in patients with non- 
insulin-dependent diabetes mellitus. The Multicenter Metformin Study 
Group. The New England journal of medicine 1995, 333(9):541-549. 
50. 
Mogul HR, Peterson SJ, Weinstein BI, Zhang S, Southren AL: Metformin and 
carbohydrate-modified diet: a novel obesity treatment protocol: preliminary 
findings from a case series of nondiabetic women with midlife weight gain 
and hyperinsulinemia. Heart disease 2001, 3(5):285-292. 
51. 
Devenny JJ, Godonis HE, Harvey SJ, Rooney S, Cullen MJ, Pelleymounter MA: 
Weight loss induced by chronic dapagliflozin treatment is attenuated by 
compensatory hyperphagia in diet-induced obese (DIO) rats. Obesity (Silver 
Spring) 2012, 20(8):1645-1652. 
52. 
Zhang Q, Dou J, Lu J: Combinational therapy with metformin and sodium- 
glucose cotransporter inhibitors in management of type 2 diabetes: 
systematic review and meta-analyses. Diabetes research and clinical practice 
2014, 105(3):313-321. 
53. 
Nowak A, Czkwianianc E: A contemporary approach to body mass regulation 
mechanisms. Przeglad gastroenterologiczny 2016, 11(2):73-77. 
54. 
Bolinder J, Ljunggren O, Kullberg J, Johansson L, Wilding J, Langkilde AM, Sugg 
J, Parikh S: Effects of dapagliflozin on body weight, total fat mass, and 

regional adipose tissue distribution in patients with type 2 diabetes mellitus 
with inadequate glycemic control on metformin. The Journal of clinical 
endocrinology and metabolism 2012, 97(3):1020-1031. 
55. 
Gregor MF, Hotamisligil GS: Inflammatory mechanisms in obesity. Annual 
review of immunology 2011, 29:415-445. 
56. 
Fernandez-Sanchez A, Madrigal-Santillan E, Bautista M, Esquivel-Soto J, 
Morales-Gonzalez A, Esquivel-Chirino C, Durante-Montiel I, Sanchez-Rivera G, 
Valadez-Vega C, Morales-Gonzalez JA: Inflammation, oxidative stress, and 
obesity. International journal of molecular sciences 2011, 12(5):3117-3132. 
57. 
Hajer GR, van Haeften TW, Visseren FL: Adipose tissue dysfunction in obesity, 
diabetes, and vascular diseases. European heart journal 2008, 29(24):2959- 
2971. 
58. 
Kalupahana NS, Moustaid-Moussa N, Claycombe KJ: Immunity as a link 
between obesity and insulin resistance. Molecular aspects of medicine 2012, 
33(1):26-34. 
59. 
Wang Z, Nakayama T: Inflammation, a link between obesity and 
cardiovascular disease. Mediators of inflammation 2010, 2010:535918. 
60. 
Wolf G: Serum retinol-binding protein: a link between obesity, insulin 
resistance, and type 2 diabetes. Nutrition reviews 2007, 65(5):251-256. 
61. 
Bluher M, Fasshauer M, Tonjes A, Kratzsch J, Schon MR, Paschke R: 
Association of interleukin-6, C-reactive protein, interleukin-10 and 
adiponectin plasma concentrations with measures of obesity, insulin 
sensitivity and glucose metabolism. Experimental and clinical endocrinology & 
diabetes : official journal, German Society of Endocrinology [and] German 
Diabetes Association 2005, 113(9):534-537. 
62. 
Goktas Z, Moustaid-Moussa N, Shen CL, Boylan M, Mo H, Wang S: Effects of 
bariatric surgery on adipokine-induced inflammation and insulin resistance. 
Frontiers in endocrinology 2013, 4:69. 
63. 
Patel PS, Buras ED, Balasubramanyam A: The role of the immune system in 
obesity and insulin resistance. Journal of obesity 2013, 2013:616193. 
64. 
Queipo-Ortuno MI, Escote X, Ceperuelo-Mallafre V, Garrido-Sanchez L, Miranda 
M, Clemente-Postigo M, Perez-Perez R, Peral B, Cardona F, Fernandez-Real JM 
et al: FABP4 dynamics in obesity: discrepancies in adipose tissue and liver 
expression regarding circulating plasma levels. PloS one 2012, 7(11):e48605. 
65. 
Garcia de la Torre N, Rubio MA, Bordiu E, Cabrerizo L, Aparicio E, Hernandez C, 
Sanchez-Pernaute A, Diez-Valladares L, Torres AJ, Puente M et al: Effects of 
weight loss after bariatric surgery for morbid obesity on vascular endothelial 
growth factor-A, adipocytokines, and insulin. The Journal of clinical 
endocrinology and metabolism 2008, 93(11):4276-4281. 
66. 
Leick L, Lindegaard B, Stensvold D, Plomgaard P, Saltin B, Pilegaard H: Adipose 
tissue interleukin-18 mRNA and plasma interleukin-18: effect of obesity and 
exercise. Obesity (Silver Spring) 2007, 15(2):356-363. 
67. 
Panee J: Monocyte Chemoattractant Protein 1 (MCP-1) in obesity and 
diabetes. Cytokine 2012, 60(1):1-12. 

68. 
Weisberg SP, McCann D, Desai M, Rosenbaum M, Leibel RL, Ferrante AW, Jr.: 
Obesity is associated with macrophage accumulation in adipose tissue. The 
Journal of clinical investigation 2003, 112(12):1796-1808. 
69. 
Okamoto A, Yokokawa H, Sanada H, Naito T: Changes in Levels of Biomarkers 
Associated with Adipocyte Function and Insulin and Glucagon Kinetics 
During Treatment with Dapagliflozin Among Obese Type 2 Diabetes Mellitus 
Patients. Drugs in R&D 2016. 
70. 
Steppan CM, Bailey ST, Bhat S, Brown EJ, Banerjee RR, Wright CM, Patel HR, 
Ahima RS, Lazar MA: The hormone resistin links obesity to diabetes. Nature 
2001, 409(6818):307-312. 
71. 
Tilg H, Moschen AR: Role of adiponectin and PBEF/visfatin as regulators of 
inflammation: involvement in obesity-associated diseases. Clin Sci (Lond) 
2008, 114(4):275-288. 
72. 
Vidal-Puig A, O'Rahilly S: Resistin: a new link between obesity and insulin 
resistance? Clin Endocrinol (Oxf) 2001, 55(4):437-438. 
73. 
Fernandez-Real JM, Vayreda M, Richart C, Gutierrez C, Broch M, Vendrell J, 
Ricart W: Circulating interleukin 6 levels, blood pressure, and insulin 
sensitivity in apparently healthy men and women. The Journal of clinical 
endocrinology and metabolism 2001, 86(3):1154-1159. 
74. 
Senn JJ, Klover PJ, Nowak IA, Mooney RA: Interleukin-6 induces cellular 
insulin resistance in hepatocytes. Diabetes 2002, 51(12):3391-3399. 
75. 
Steinberg GR: Inflammation in obesity is the common link between defects in 
fatty acid metabolism and insulin resistance. Cell Cycle 2007, 6(8):888-894. 
76. 
Moore KW, de Waal Malefyt R, Coffman RL, O'Garra A: Interleukin-10 and the 
interleukin-10 receptor. Annual review of immunology 2001, 19:683-765. 
77. 
Hotamisligil GS, Shargill NS, Spiegelman BM: Adipose expression of tumor 
necrosis factor-alpha: direct role in obesity-linked insulin resistance. 
Science 1993, 259(5091):87-91. 
78. 
Kanety H, Feinstein R, Papa MZ, Hemi R, Karasik A: Tumor necrosis factor 
alpha-induced phosphorylation of insulin receptor substrate-1 (IRS-1). 
Possible mechanism for suppression of insulin-stimulated tyrosine 
phosphorylation of IRS-1. J Biol Chem 1995, 270(40):23780-23784. 
79. 
Warne JP: Tumour necrosis factor alpha: a key regulator of adipose tissue 
mass. J Endocrinol 2003, 177(3):351-355. 
80. 
Vasilakou D, Karagiannis T, Athanasiadou E, Mainou M, Liakos A, Bekiari E, 
Sarigianni M, Matthews DR, Tsapas A: Sodium-glucose cotransporter 2 
inhibitors for type 2 diabetes: a systematic review and meta-analysis. Annals 
of internal medicine 2013, 159(4):262-274. 
81. 
Rosenstock J, Ferrannini E: Euglycemic Diabetic Ketoacidosis: A Predictable, 
Detectable, and Preventable Safety Concern With SGLT2 Inhibitors. Diabetes 
care 2015, 38(9):1638-1642. 
82. 
Peters AL, Buschur EO, Buse JB, Cohan P, Diner JC, Hirsch IB: Euglycemic 
Diabetic Ketoacidosis: A Potential Complication of Treatment With Sodium- 
Glucose Cotransporter 2 Inhibition. Diabetes care 2015, 38(9):1687-1693. 

83. 
Erondu N, Desai M, Ways K, Meininger G: Diabetic Ketoacidosis and Related 
Events in the Canagliflozin Type 2 Diabetes Clinical Program. Diabetes care 
2015, 38(9):1680-1686. 
84. 
Ferrannini E, Muscelli E, Frascerra S, Baldi S, Mari A, Heise T, Broedl UC, Woerle 
HJ: Metabolic response to sodium-glucose cotransporter 2 inhibition in type 
2 diabetic patients. The Journal of clinical investigation 2014, 124(2):499-508. 
85. 
Luzi L, Barrett EJ, Groop LC, Ferrannini E, DeFronzo RA: Metabolic effects of 
low-dose insulin therapy on glucose metabolism in diabetic ketoacidosis. 
Diabetes 1988, 37(11):1470-1477. 
86. 
Shamah- Levy T V-HS, Rivera-Dommarco J. : Manual de Procedimientos para 
Proyectos de Nutrición In: 2006; Cuernavaca, Mexico; 2006. 
87. 
Velázquez-Monroy O L-EA, Tapia-Olarte F, Romo-López L, Carrillo-Toscano J, 
Colín-Cario M, Montes-Reyes G: Manual de Procedimientos. Toma de medidas 
clínicas y antropométricas en el adulto y adulto mayor. In: 2002; México, D.F; 
2002. 

11. APPENDIX 
Appendix 1. Criteria for diagnosis of prediabetes and diabetes according American 
Diabetes Association (ADA) guidelines. 
 
 
Prediabetes 
Diabetes 
Glycated hemoglobin 
5.7 - 6.4% 
≥ 6.5% 
Fasting plasma glucose 
100 - 125 mg/dl 
≥ 126 mg/dl 
Oral glucose tolerance test 140 - 199 mg/dl 
≥ 200 mg/dl 
Random plasma glucose 
≥ 200 mg/dl 
 
Considerations 
1. The fasting glucose test must be performed after caloric deprivation for at least 8 
hours. 
2. Oral glucose tolerance test must be performed as follows: 
a. The patient must have at least an 8-hour fasting. 
b. Basal venous plasma glucose will be determined. 
c. The test should be performed as described by the WHO, using a glucose load 
containing the equivalent of 75 g anhydrous glucose dissolved in water and a 
new serum glucose determination will be performed after two hours of the 
glucose administration. 
d. The test will be considered invalid if the patient is not able to take the complete 
glucose load or if vomiting is present during the test 
e. The test will not be performed in patients with a basal glucose higher tan 200 
mg/dl. 
f. 
Glucose tolerance test is required for patients classified as prediabetic. 
g. A random glucose higher than 200 mg/dl is a valid test only for patients with 
evident symptoms of hyperglycemia or hyperglycemic crisis. 
h. The ADA recommends that all patients classified as obese by BMI should be 
tested for diabetes or prediabetes. 

Appendix 2. Collecting data sheet 
INSTITUTO MEXICANO DEL SEGURO SOCIAL 
 
 
Name: 
 
Social 
security 
ID  
number: 
 
 
Treatment 
code 
 
 
 
Birthdate:  
Inclusion date:  
 
Direction: 
 
Phone number:  
 Gender:  
 Height:  
 
Age: 
 
 
Relevant history (Cross out the appropriate option) 
Smoking ( Yes ) ( No ) 
Age 
from 
beginning: 
 
 
Number 
of 
years 
 
Cigarettes/day:  
 
Alcoholism ( Yes ) ( No ) 
Age from beginning:  
 Number of years 
 
Drinks/week:  
 
Cancer history in family (father, mother, aunt, uncle, grandfather/mother) ( Yes ) ( No ) 
Type: 
 
Comorbidities 
Yes 
No 
Age from diagnosis 
Drugs (Frequency/doses) 
Hypothyroidism 
Prediabetes 
Diabetes Mellitus 
Hypertension 
Hypertriglyceridem 
ia 
Myocardial 
infarction/angina 
OSAH syndrome 

Osteoarthritis 
 
Labs 
Initial 
Final 
Labs 
Initial 
Final 
Glucagon (ng/ml) 
Creatinine clearance 
(ml/min) 
Ghrelin (pg/ml) 
Adiponectin (pg/ml) 
iPTH (ng/ml) 
Resistin (ng/ml) 
Calcium (mg/dl) 
IL-6 (pg/ml) 
Phosphorus (mg/dl) 
IL-10 (pg/ml) 
Magnesium (mg/dl) 
 
 
 
 
 
 
Name: 
NSS: 
 
Parameter 
1 month 
3 months 
6 months 
12 months 
Weight (kg) 
BMI (kg/m2) 
Waist 
circumference (cm) 
Systolic 
blood 
pressure (mmHg) 
Diastolic 
blood 
pressure (mmHg) 
Glucose (mg/dl) 
HbA1c (%) 
TAG (mg/dl) 
TC (mg/dl) 
HDL-c (mg/dl) 
LDL -c(mg/dl) 
Urinary 
infection 
(y/n) 
Ketonuria (y/n) 
Proteinuria (y/n) 
Leukocyturia (y/n) 
Nitrite (y/n) 
Sodium (mEq/L) 
Potassium (mEq/L) 

Calcium (mg/dl) 
Phosphorus (mg/dl) 
Magnesium (mg/dl) 
Drugs 
(hypoglycemic 
agents, 
antihypertensives, 
treatment 
for 
dyslipidemia) 

Appendix 3. Procedures for clinical and anthropometrical measurements 
Weight assessment 
Required material: adult scale, with a maximum capacity of 300 kg and precision of 100 g, not 
mobile. This scale is calibrated with known tare weight (10 kg) each month and is in one of the 
offices of the Obesity Clinic. 
 
Process: 
· 
The measurement is carried out with the least possible clothing and shoes. 
· 
The subject must be step on the scale by placing its feet parallel in the center of the 
scale, facing the examiner. Subjects must be upright, staring straight ahead, 
unmoving, with their arms falling naturally at their sides. 
· 
The lecture is taken when the central needle is in the middle of the 2 margins and 
unmoving. 
 
Height assessment 
 
Required material: a stadimeter fixed to the wall, which consists of a measuring tape with 2 m 
long and a mobile bracket with a 90 ° angle. 
 
Process: 
· 
Before starting the measurement, subjects will be asked to take off their shoes and 
any object over the head, as pins, bows, high hairstyles, braids, etc 
· 
The height is measured standing, with the back and head fully supported on the wall. 
· 
The midline of the body must coincide with the midline of the tape stadimeter. 
· 
The anthropometrist must be placed on the left side of the subject. With his left hand, 
he takes subjects’ chin to control his head and direct it towards the plane of Frankffort; 
with his right hand slide the movable piece vertically to the tape, touching the coronal 
part of the head at an angle of 90 °. 
· 
The data observed is registered. 
 
Assessment of waist circumference. 
Required material: fiberglass tape with a capacity of 200 cm and accuracy of 1 mm. 
Process: 
· 
Waist circumference is taken with the subject at standing position. 
· 
The tape should be parallel to the floor. 
· 
Another person must ensure that in the back of the body the tape is horizontally and 
not creating pressure on the skin. 
· 
In very obese people waist is difficult to evaluate, so the tape should measure the 
minimum circumference of the abdomen in the area between the costal margin and 
the iliac crests. The measurement is read in cm. 

Blood pressure measurement. 
Required material: aneroid sphygmomanometer with special bracelet for obese adults 
Process: 
· 
The patient should refrain from smoking, drinking coffee or cola products at least 30 
minutes before measurement. 
· 
The patient must be sitting with good back support and his arm flexed at heart level. 
· 
The measurement is carried out after at least 5 minutes of rest. 
· 
A bracelet of suitable size will be used to ensure an accurate measurement. The air 
chamber must cover at least 3/4 of the length of the arm and at least 80% of the arm 
circumference. 
· 
Both systolic and diastolic pressures must be registered; the appearance of the first 
sound defines the appearance of diastolic pressure and the last noise is used to define 
diastolic pressure. 
· 
The blood pressure value is the average of two measurements, separated by two 
minutes or more. If the two pressures differ by more than 5 mm Hg, two additional 
measurements are made and the average will. 
 
 
 
Appendix 4. ELISA technique for cytokine determination. 
 
Required material: 
· 
Capture antibody (360 μg/ml of anti-human mouse cytokine reconstituted with 1 mL of 
PBS). 
· 
Detection antibody (9 mg/ml of anti-human goat cytokine biotinylated reconstituted 
with 1 mL of reaction diluent). 
· 
Standard (120 ng/ml recombinant human cytokine reconstituted with distilled or 
deionized water). 
· 
Streptavidin-HRP (1 ml of streptavidin conjugated with horseradish peroxidase). 
· 
PBS: 137 mM NaCl, 2.7 mM KCl, 8.1 mM Na2HPO4, 1.5 mM KH2PO4, pH 7.2-7.4, 
filter 0.2 μm. 
· 
Washing Buffer: 0.05% Tween 20 in PBS, pH 7.2-7.4. 
· 
Diluent reaction: 1% BSA in PBS, pH 7.2-7.4. 
· 
Substrate 
Solution: 
1:1 mixture 
of 
Reagent A (H2O2) 
with 
Reagent 
B 
(tetramethylbenzidine) 
· 
Stop solution (2NH2SO4). 
· 
Microplate reader. 
 
Plate’s preparation: 

1) Dilute capture antibody at a concentration that will work on PBS without carrier protein. 
Immediately cover the 96-well microplate with 100 L of diluted capture antibody. Seal 
the plate and incubate overnight at room temperature. 
2) Vacuum and wash each well with washing buffer, repeating the process twice in a total 
of three washes. Wash by filling each well with 400 μL of washing buffer. Complete 
removal of liquid at each step is essential for good performance. After the last wash 
remove any remaining of washing buffer by aspiration or by inverting the plate on a 
paper towel. 
3) Block plates by adding 300 μL of the dilution reaction to each well. Incubate at room 
temperature for at least one hour. 
4) Repeat washing / extraction process (Step 2). The plates are ready to add the sample. 
 
For samples: 
1. Add 100 μL of sample or controls in the reaction diluent to each well. Cover it with tape 
and incubate 2 h at room temperature. 
2. Repeat aspirate / wash process. (Step 2) 
3. Add 100 uL of detection antibody (diluted in the reaction diluent) to each well. Cover 
with a new adhesive tape and incubate 2 h at room temperature. Repeat aspirate / 
wash process. (Step 2) 
4. Add 100 μL of dilution of HRP-streptavirine to each well. Cover the plate and incubate 
for 20 min at room temperature, without exposing the plate. 
5. Repeat wash / aspirate process (Step 2). 
6. Add 100 μL of substrate solution to each well. Incubate for 20 min at room temperature. 
7. Add 50 μL of stop solution to each well. Cover the plate and mix thoroughly. 
8. Determine the optical density of each well immediately, using a microplate reader at 
450 nm. If available, adjust wavelength at 540 nm or 570 nm. If is not available, 
subtract readings of 540 or 570 to 450 nm. This subtraction corrects the optical 
imperfections on each plate. The readings at 450 nm without correction may be high 
or low accuracy. 
 
Results 
1) Make a standard curve using the appropriate cytokine at a concentration of 1, 10, 100 
and 1000 pg/ml, obtaining and plotting the obtained absorbances. 
2) Extrapolate the results of the sample and calculate the concentration according to the 
absorbance. 
3) If sample dilution was performed, the concentration should be corrected by multiplying 
by the dilution factor. 

Appendix 5. List of adverse events CTCAE (Common Terminology Criteria for Adverse 
Events v4.0) 
 
 
Grade 
Description 
Grade 1 
Minimal, asymptomatic or mild symptoms. No intervention required, only 
clinical follow-up. 
Grade 2 
Moderated. Non-invasive intervention, minimal or local intervention, it may 
impair activities of daily living (ADL) for their age. 
Grade 3 
Severe or medically significant but not immediately life-threatening; 
hospitalization or prolongation of hospitalization indicated; disabling; limiting 
self care ADL. 
Grade 4 
Life-threatening, urgent intervention indicated. 
Grade 5 
Death related to adverse event. 
 
Consideration: impaired daily activities refers to activities required for health and quality of life, 
such as preparing meals, buying garments, using the telephone, handling Money, etc. Self-care 
activities include bathing, getting dressed or undressed, feeding, toilet use, taking medicine and 
being bedridden. 
 
Example of the use of CTCAE: Infections and infestations 
 
Adverse event 
1 
2 
3 
4 
5 
Urinary 
tract 
infection 
Definition: 
  A 
disorder caused 
by the infectious 
process involving 
the urinary tract, 
usually 
 the 
bladder 
and 
urethra. 
- 
Localized; 
local 
intervention 
(antibiotic, 
antifungal or 
antiviral 
as 
needed) 
IV 
antibiotic, 
antifungal, 
or 
antiviral 
intervention 
indicated; 
radiologic 
or 
operative 
intervention 
indicated 
Life- 
threatening 
consequences 
; 
urgent 
intervention 
indicated 
Death 
Vaginal Infection 
Definition: 
A 
disorder 
characterized by 
an 
infectious 
process involving 
the vagina 
- 
Localized; 
local 
intervention 
indicated 
(e.g., topical 
antibiotic, 
antifungal, 
or antiviral) 
IV 
antibiotic, 
antifungal, 
or 
antiviral 
intervention 
indicated; 
radiologic 
or 
operative 
intervention 
indicated 
Life- 
threatening 
consequences 
; 
urgent 
intervention 
indicated 
Death 

Vulvar infection. 
Definition: 
A 
disorder 
characterized by 
an 
infectious 
process involving 
the vulva 
Localized, 
local 
interventio 
n indicated 
Oral 
intervention 
indicated 
(e.g., 
antibiotic, 
antifungal, 
antiviral) 
IV 
antibiotic, 
antifungal, 
or 
antiviral 
intervention 
indicated; 
radiologic 
or 
operative 
intervention 
indicated 
Life- 
threatening 
consequences 
; 
urgent 
intervention 
indicated 
Death 

Appendix 6. Adverse event registry form 
Adverse events (effects/reactions) presented by patients included in investigation 
protocols. 
 
México City,  
, 20    
I, Aldo Ferreira Hermosillo, M. Sc. as the Principal Investigator of the protocol titled “Effectiveness 
of the treatment with dapagliflozin and metformin compared to metformin monotherapy for weight 
loss and its effects on waist circumference, triacylglycerol concentration, blood pressure and 
inflammatory cytokines on diabetic and prediabetic patients with obesity class III. Open, 
randomized clinical trial.” 
Registered number:  
 
Date of authorization:  
 
Site: Hospital de Especialidades CMN SXXI 
 
Inform that I have reviewed each and every adverse event (effect/reaction) presented by the 
patients included in this investigation protocol. These events are described as follows: 
 
Date 
Case 
number 
Reaction 
description 
Outcome 
Suspected 
relationship to the 
protocol 
intervention 
Initial or follow up 
report 
 
Please mark with an X one of the two options. In the cases where the second line is marked, 
please explain the motives: 
( 
) After careful analysis, I declare that none of the adverse events described previously 
demands for suspension or cancelling of the investigation protocol. 
( 
) Protocol has been suspended due to the following reasons: