Clinical trial NCT03880162: Metabolic Effects of a Low Carbohydrate Versus a Standard Diet in Morbidly Obese With Prediabetes
Official title: Metabolic Effects of a Low Carbohydrate Versus Energy-matched Standard Diet in Morbidly Obese Individuals With Prediabetes
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: PreDiabetes
Obesity, Morbid
Bariatric Surgery Candidate
Keywords: Prediabetes
Bariatric Surgery
Low-carb diet
Lead sponsor: Insel Gruppe AG, University Hospital Bern
Sponsor class: OTHER
First posted: 2019-03-19
Enrollment: 20
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Intervention model description: Single-centre, randomized parallel study
Primary purpose: TREATMENT

Brief summary: To investigate the metabolic effects of a low carbohydrate versus energy-matched standard diet in morbidly obese individuals with prediabetes awaiting bariatric surgery.

Detailed description: The metabolic benefits of calorie restriction in obese people with or without impaired glycaemia are well-established. The impact of diet composition, however, remains poorly understood. Hepatic lipid content strongly correlates with hepatic insulin resistance, which is a key feature of the pre-diabetic state. The investigators hypothesize that a low carbohydrate diet compared to an energy-matched standard diet in morbidly obese patients with prediabetes scheduled for bariatric surgery results in greater reduction in liver fat.

Eligibility criteria: Inclusion Criteria:

* Female and male subjects aged 18 years or older
* BMI \>35 kg/m2 awaiting bariatric surgery
* Pre-diabetes according to American Diabetes Association criteria (HbA1c 5.7%-6.4%)
* Capacity to give informed consent and adhere to study procedures

Exclusion Criteria:

* Excess alcohol consumption (\> 3 units/day for men, \> 2 units/day for women)
* Moderate to severe kidney disease
* Nephrolithiasis
* Pregnancy/breastfeeding
* Current participation in another clinical trial
* Claustrophobia
* MRI-contraindications (pacemaker/defibrillator, neurostimulator, drug pump, cochlear implant, heart valve/vascular clips, shunt valve)

Primary outcomes:
measure: Change from baseline in intrahepatic triglyceride content
timeFrame: 2 weeks
Secondary outcomes:
measure: Change from baseline in body weight
timeFrame: 2 weeks
measure: Change from baseline in liver size
timeFrame: 2 weeks
measure: Change from baseline in visceral adipose tissue
timeFrame: 2 weeks
measure: Change from baseline in whole body fat mass
timeFrame: 2 weeks
measure: Change from baseline in insulin secretion
timeFrame: 2 weeks
measure: Change from baseline in insulin sensitivity
timeFrame: 2 weeks
Other outcomes:
measure: Change from baseline in plasma metabolome
timeFrame: 2 weeks
measure: Change from baseline in plasma transcriptome
timeFrame: 2 weeks
measure: Change from baseline in Fibroblast Growth Factor 21
timeFrame: 2 weeks
measure: Change from baseline in adipose tissue inflammation
timeFrame: 2 weeks
measure: Change from baseline in gut microbiota composition
timeFrame: 2 weeks
measure: Change from baseline levels of secondary bile acids
timeFrame: 2 weeks
measure: Change in frequency of immune cells (T-, B-, NK-cells, monocytes, neutrophils)
timeFrame: 2 weeks
measure: Change in immunometabolism of T-cells
timeFrame: 2 weeks
measure: Occurrence of surgical complication
timeFrame: Day of surgery until 2 weeks post-surgery
measure: Length of hospital stay
timeFrame: Day of surgery until 2 weeks post-surgery
Locations:
city: Bern
country: Switzerland
facility: Division of Endocrinology, Diabetes and Clinical Nutrition, Bern University Hospital
Study officials:
affiliation: Inselspital, Bern University Hospital, University of Bern
name: Lia Bally, MD PhD
role: PRINCIPAL_INVESTIGATOR
References: