Effects of Omega-3 PUFA Supplementation on Insulin Resistance and Lipid Metabolism in Patients with T2DM: A Systematic Review and Meta-Analysis

Abstract

Objectives: Omega-3 PUFA could reduce the risk of metabolic syndrome and is beneficial to a wide range of chronic diseases, such as cardiovascular disease, type 2 diabetes mellitus (T2DM) and cancer. While, its effect on insulin sensitivity and lipid metabolism remains controversial. This meta-analysis summarizes the extant evidence between the supplement of Omega-3 PUFA and lipid metabolism and assesses whether Omega-3 PUFAs could improve the dyslipidemia in the T2DM population. Methods: Databases including PubMed, Elsevier, and the Cochrane Library were searched until march 2019 for RCTs investigating the effect of Omega-3 PUFAs supplementation on lipid metabolism. Data were extracted using Rveman 5.3 statistical software and analyzed using a fixed effect model. The effect size is given in a standardized mean difference (SMD) and a 95% confidence interval (95% CI). Results: A total of 26 cases of RCT were included in this paper. In the combined analysis, supplementation of omga-3 PUFA significantly affected the level of total cholesterol (TC), high density lipoprotein (HDL), insulin resistance (HOMA-IR) in patients with T2DM, in which HOMA-IR decreased 0.2, TG decreased 0.56 mg/dL, TC decreased 0.14 mg/dL, HDL increased 0.14 mg/dL. The changes in fasting insulin (FINS) and low density lipoprotein (LDL) index were statistically obvious, while they both showed decreasing trends. In the subgroup analysis based on intervention time and doses of Omega-3 PUFA, with the increase of intervention time and supplementary doses, the change trend of each index became more and more significant, and towards the better improvement in lipid metabolism. The sensitivity analysis indicated that the results were robust. Conclusions: The addition of omega-3 PUFA may improve insulin sensitivity and lipid metabolism in the T2DM population, which may provide a dietary reference for diabetic patients characterized by these disorders.