No favourable effects of Cr (III) supplementation on lipid metabolism on type 2 Diabetes Mellitus: a meta-analysis of single and doubleblind, randomized, placebo controlled trials.

Introduction. Type 2 diabetes mellitus is an important global health issue which prevalence has been increasing in the last years. Many studies have linked chromium supplementation with improvement of type 2 diabetes mellitus.Aim. Perform a meta-analysis of single and double-blind, randomized, placebo controlled trials, where participants diagnosed of type 2 DM or glucose intolerants were supplemented with Cr (III).Methods. Systematic literature search in electronic databases was conducted, using the following search terms: (diabetes) AND (chromium), until July, 2016. Eligible studies were limited to double or single-blind, parallel group, placebo-controlled, randomizedclinical trials, comparing Cr mono or combined supplementation at least for 30 days against placebo, in subjects diagnosed of type 2 DM or with glucose intolerance.Results. Total doses of Cr supplementation and brewer’s yeast ranged from 20 to 1000 μg/day, and duration of supplementation ranged from 30 to 120 days. No statistically significant reduction was found in HDL-C (p=0.63), LDL-C (p=0.53) and TG (p=0.34)compared to placebo; with a weighted average effect size of -0.44 (95% CI: -2.2 to 1.33) mg/dL, -1.43 (95% CI: -5.94 to 3.08) mg/dL and -7.43 (95% CI: -22.67 to 7.82) mg/dL, respectively.Conclusion. Evidence in our study suggests no favourable effects of chromium supplementation on lipid metabolism control in patients with type 2 diabetes.