Omega-3 polyunsaturated fatty acid and insulin sensitivity: A meta-analysis of randomized controlled trials

Background &aim: n-3 PUFA has been shown to decrease the risk of several components of the metabolic syndrome; however, the role of n-3 PUFA on glucose metabolism is not clear. Our aim was to systematically review the effect of n-3 PUFA on IS by conducting a meta-analysis of available RCTs. Methods: We followed the guidelines of Cochrane's review of systematic interventions. We searched MEDLINE, EMBASE, CENTRAL and clinicaltrials.gov from the beginning of each database until October 2010. Meta-analysis was performed using a random effects model to estimate a pooled SMD and the corresponding 95% Cl. Results: From 303 screened citations, 11 RCTs (n = 618) were eligible for inclusion in the analysis. In a pooled estimate, n-3 PUFA intervention had no effects on IS compared to placebo (SMD 0.08, 95% Cl -0.11-0.28). Similarly, n-3 PUFA had no effects on IS in sub-group analyses (Type 2 diabetes vs. other population; QUICKI and other test subgroups). In the HOMA subgroup, n-3 PUFA was associated with a statistically significant increase in IS (SMD 0.30, Cl 0.03-0.58) when compared to placebo. Conclusion: This meta-analysis is consistent with a lack of n-3 PUFA effects on IS. (C) 2011 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.