The effect of omega-3 supplementation on glycemic indices and lipid profile in type 2 diabetic patients with non-alcoholic fatty liver disease: A double-blind, randomized, clinical trial

Abstract

INTRODUCTION: Serum phospholipid omega-3 fatty acid levels in patients suffering from both type 2 diabetes (T2DM) and non-alcoholic fatty liver (NAFLD) are lower than in their healthy counterparts. Omega-3 supplementation can be effective in controlling glycemic indices in T2DM, and in improving lipid profiles in T2DM and NAFLD as well. The aim of this study was to evaluate the effects of omega-3 fatty acid supplementation on glycemic control and lipid profile in patients with T2DM and NAFLD. METHODS: In this randomized double-blind placebo-controlled clinical trial, 60 patients with T2DM and NAFLD were enrolled. The participants were randomly divided into two groups. The omega-3 group (OG) received capsules containing omega-3 fatty acids (2g/d), and the placebo group (PG) received placebo capsules (2g/d) during a12 week period. Dietary intake was assessed with 24-hour dietary recalls. Fasting blood samples and anthropometric measurements were collected at the baseline and after 12 weeks. Serum levels of glycemic indices (fasting blood glucose (FBG) levels, glycosylated hemoglobin (HbA1c)) and lipid profile (levels of triglyceride (TG), total cholesterol (TC), low density lipoprotein cholesterol (LDL-c) and high density lipoprotein cholesterol (HDL-c)) were measured. RESULTS: Fifty-six patients completed the study. Paired t-test revealed no significant differences in the baseline measurements between the two groups. At the end of the study compared with the PG, the OG had a significant reduction in serum TG levels. However, there was no significant effect of omega-3 supplementation on the other parameters: the mean FBG or HbA1c concentration, neither on TC, LDL-c and HDL-c levels. CONCLUSION: Two grams per day of omega-3 supplementation after 12 weeks led to a significant reduction in serum TG levels in patients with T2DM and NAFLD. However, no significant effects were observed on FBG, HbA1c, TC, LDL-c, and HDL-c levels.

Effect of omega-3 supplementation on cardiometabolic indices in diabetic patients with non-alcoholic fatty liver disease: a randomized controlled trial

“…The study of Dasarathy et al [ 24 ] reported that omega-3 supplementation has no effect on serum concentrations of TC, LDL-c and HDL-c. In addition, our original study demonstrated that omega-3 supplementation for 12 weeks reduced serum TG levels, but could not improve serum concentrations of TC, LDL-c and HDL-c in diabetic patients with NAFLD [ 26 ]. Moreover, the study of Scorletti et al [ 41 ] demonstrated that after intervention for 15–18 months, there is no significant difference between the omega-3 group (4 g/d) and the placebo group in levels of TC, LDL-c and HDL-c.…”

“…It seems, 2–4 g/d omega-3 has a beneficial effect on TG, but not TC, LDL-c and HDL-c. Omega-3 by inducing β-oxidation, decreasing VLDL synthesis, regulating gene expression of sterol-regulatory element-binding protein-1 (SREBP-1) and carbohydrate response element binding protein (ChREBP), modulating the TG synthesis, activating phosphatidic acid, diacylglycerol acyltransferase as well as LPL, and reducing the TG clearance from circulating VLDL particles can regulate serum TG [ 17 , 21 , 44 – 46 ]. To follow the principals of ethics in research, we clarify that our research group reported the effect of omega-3 fatty acids on fatty liver, visceral adiposity index, insulin resistance, body composition and lipid profile, previously [ 26 , 47 ]. We used the same data for the present article.…”

“…We used the same data for the present article. The flowchart of eligibility, screening and follow-up as figure as well as some necessary information as table and sample size information of our previous article [ 26 ] were added to the present article.…”

“…In our previous article that reported the findings of insulin resistance, body composition and lipid profile [ 26 ], the sample size was estimated to be 30 for each group with 95% confidence interval, α = 0.05, power = 80%. The power analysis was performed again, and we estimated power = 80% for this article.…”

“…In addition, PUFAs through modulating endothelium-relaxing, stimulating the production of gasotransmitters leading to vasorelaxation such as nitric oxide (NO) and hydrogen sulphide, and decreasing the production of endothelin 1 and angiotensin II as vasoconstricting factors can improve endothelial dysfunction and atherosclerosis [ 16 , 21 ]. Some investigations with contradictory results have investigated the effects of omega-3 fatty acids on cardiometabolic outcomes [ 22 – 26 ]. The findings of these studies are inconsistent.…”