Effect of magnesium supplementation on type 2 diabetes associated cardiovascular risk factors: a systematic review and meta-analysis

BackgroundCardiovascular disorders remain the leading cause of death in type 2 diabetic patients. In the present study, a systematic review and a meta-analysis of randomised controlled trials (RCTs) were conducted aiming to evaluate the effect of magnesium supplementation on type 2 diabetes (T2D) associated cardiovascular risk factors in both diabetic and nondiabetic individuals. MethodsPubMed, Scopus, Cochrane, Web of Science and Google Scholar databases were searched from inception to 30 June 2016 aiming to identify RCTs evaluating the effect of magnesium supplementation on T2D associated cardiovascular risk factors. The data were analysed using a random effect model with inverse variance methodology. Sensitivity analysis, risk of bias analysis, subgroup analysis, meta-regression and publication bias analysis were also conducted for the included studies using standard methods. ResultsFollowing magnesium supplementation, a significant improvement was observed in fasting plasma glucose (FPG) [weighted mean difference (WMD) = -4.641 mg dL(-1), 95% confidence interval (CI) = -7.602, -1.680, P = 0.002], high-density lipoprotein (HDL) (WMD = 3.197 mg dL(-1), 95% CI = 1.455, 4.938, P < 0.001), low-density lipoprotein (LDL) (WMD = -10.668 mg dL(-1), 95% CI = -19.108, -2.228, P = 0.013), plasma triglycerides (TG) (WMD = -15.323 mg dL(-1), 95% CI = -28.821, -1.826, P = 0.026) and systolic blood pressure (SBP) (WMD = -3.056 mmHg, 95% CI = -5.509, -0.603, P = 0.015). During subgroup analysis, a more beneficial effect of magnesium supplementation was observed in diabetic subjects with hypomagnesaemia. ConclusionsMagnesium supplementation can produce a favourable effect on FPG, HDL, LDL, TG and SBP. Therefore, magnesium supplementation may decrease the risk T2D associated cardiovascular diseases, although future large RCTs are needed for making robust guidelines for clinical practice.