Sardine-enriched Diet for Prevention Type 2 Diabetes in Elderly and Prediabetic Population
Phase: NA
Conditions: Diabetes Mellitus, Type 2, PreDiabetes, Diet Habit, Diabetes, Nutritional and Metabolic Disease
Sponsor: Institut d'Investigacions Biomèdiques August Pi i Sunyer

Protocol 28/11/2013 
 
PROTOCOL clinictrials.org 
Subjects and study design  
The calculation of the sample size in the present study has been done so that we ensure a 
power of 90%, in order to lower the conversion rate to DT2 up to 5% in the sardine group, 
compared to the 20% conversion in the control group. Thus, with a level of significance of 0.05 
and using the statistical program STATA (STATA.11 software), it was calculated that 114 
patients would be required per group. Considering a 10% abandonment rate, 125 patients 
would be required for inclusion visits. Recruited patients will come from three primary care 
centers in Barcelona (CAP Les Corts, Casanova and Borrell). After recruitment, the 250 
participants had to be assigned to the sardine group (125 people) or the control group (125 
people). (Figure 1) 
Individuals aged 65 years old or more with a fasting diagnosis of altered basal glycemia (100-
125 mg/dL) interested in joining the nutritional intervention could do it provided that the 
informed consent was obtained before starting any activity related to the study.  
Otherwise, the exclusion criteria were the following: suspicion or consciousness of 
hypersensibility to sardines, chronic treatment with oral steroids and/or AINEs, treatment with 
oral antidiabetic drugs or insulin, treatment with immunosuppressive drugs, diagnosis of an 
active neoplasia, diagnosis of VIH or SIDA, abnormal hepatic profile (>6-fold normal values), 
diagnosis of acute psychiatric syndrome, presence of acute concomitant disease which 
required more than 7 days for recovery, major cardiovascular event (ictus or myocardial 
infarction) during the previous month to randomization and any other condition considered as 
inopportune by researchers. 
 
Dietary assessment  
All the recruited individuals were randomly distributed among two groups: the control group 
(CG) and the sardine group (SG).  
Both groups received the same nutritional education, based on ADA clinical guidelines. The 
nutritional recommendations included intaking carbohydrate from vegetables, legumes, whole 
grains or legumes, avoiding those with higher glycemic load. A dietary plan similar to 
Mediterranean diet was also recommended, emphasizing monounsaturated and 
polyunsaturated fats, and those foods rich in long ω3-FA such as nuts and seeds. Alcohol 
should have been limited. Emphasis was placed on the plate method (ADA) for the correct 
distribution of macronutrients. Group education was performed before starting the study and 
every four months, in order to reinforce nutritional knowledge.  
Besides, the SG received 200g of sardine per week. Sardines were canned in olive oil and, in 
order to obtain more accurate results, they were provided by IDIBAPS.  

Protocol 28/11/2013 
 
 
Figure 1. Overview of the recruitment process.  
 
Visits  
As shown in Figure 2, a total of six visits were programmed during the year of the clinical study. 
 
Figure 2. Overview of the 12 months visits programming. 
The first visit was used to evaluate the candidates, to obtain informed consent and to do the 
randomization so in the second visit candidates could start the intervention. In order to 
perform gene expression analysis, serum was obtained at the second visit (V0) and at the last 
visit (V12). 
 
Ethical issues  
The study will be carried out in compliance with the Declaration of Helsinki (current version, 
currently Fortaleza, Brazil, October 2013) and in accordance with the protocol and with the 
pertinent legal requirements, Law 14/2007 of July 3 on Biomedical Research.  
Permission has been secured from all participants to use the aforementioned data in the 
present proposal, in the form of signed written consent, prior to the start of the project.  
 
Data management  
The data we plan to collect and generate within the framework of our proposal will have the 
purpose of answering questions regarding the mechanisms underlying a sardine-rich diet’s 
beneficial effects on T2D prevention.