Effects of dietary supplementation on progression to type 2 diabetes in subjects with prediabetes: a single center randomized double-blind placebo-controlled trial

Abstract

Objectives: To examine the effect of dietary supplements on diabetic risk progression, blood glucose level, and lipid profiles. Methods: A randomized, double-blind, placebo-controlled study was conducted at Rajavithi hospital, Thailand. Participants with prediabetes were randomly allocated to three arms of dietary supplements: placebo (PL) or curcumin plus fish oil and vitamin D (CFD), or curcumin plus fish oil (CF) for 24 weeks. Primary outcomes were the progression of glycemic status and the progression to overt diabetes at 24-week and 36-week follow-ups. Secondary outcomes were changes in glycemic profiles (fasting plasma glucose, 75 g OGTT 2-h plasma glucose or HbA1C), body weight, BMI and lipid profiles. Results: A total of forty-seven participants (PL, n = 16; CFD, n = 15; CF, n = 16) were included in the study. At the 24-week follow-up, the participants with worsening glycemic status in the intervention groups were lower, CFD, CF and Placebo, 14.29%, 13.33% and 31.25%, respectively. However, the primary outcome, progression of glycemic status, was statistically different, with p - value = 0.046 (p < 0.05) when excluding previous diabetes in the study. As well as the incidence of type 2 diabetes at 24-week follow-up was not statistically different between the three groups, 14.29%, 13.33%, and 12.5%, p - value = 0.699 (p < 0.05) in CFD, CF, PL group, respectively. The secondary outcomes also failed to demonstrate the effect of dietary supplements on blood glucose, lipid profiles, weight, BMI and blood chemistry. Conclusion: The combined dietary supplements which contained curcumin-fish oil-vitamin D, could lower the glycemic status progression in prediabetes at six months follow-up and were well-tolerated among the participants.