Effect of magnesium supplementation on glucose metabolism in people with or at risk of diabetes: a systematic review and meta-analysis of double-blind randomized controlled trials

Abstract

Although higher dietary intakes of magnesium (Mg) seem to correspond to lower diabetes incidence, research concerning Mg supplementation in people with or at risk of diabetes is limited. Thus, we aimed to investigate the effect of oral Mg supplementation on glucose and insulin-sensitivity parameters in participants with diabetes or at high risk of diabetes compared with placebo. A literature search in PubMed, EMBASE, SCOPUS, Cochrane Central Register of Controlled Trials and Clinicaltrials.gov without language restriction, was undertaken. Eligible studies were randomized controlled trials (RCTs) investigating the effect of oral Mg supplementation vs placebo in patients with diabetes or at high risk of diabetes. Standardized mean differences (SMD) and 95% confidence intervals (CIs) were used for summarizing outcomes with at least two studies; other outcomes were summarized descriptively. Eighteen RCTs (12 in people with diabetes and 6 in people at high risk of diabetes) were included. Compared with placebo (n=334), Mg treatment (n=336) reduced fasting plasma glucose (studies=9; SMD=-0.40; 95% CI: -0.80 to -0.00; I=77%) in people with diabetes. In conditions in people at high risk of diabetes (Mg: 226; placebo=227 participants), Mg supplementation significantly improved plasma glucose levels after a 2 h oral glucose tolerance test (three studies; SMD=-0.35; 95% CI: -0.62 to -0.07; I=0%) and demonstrated trend level reductions in HOMA-IR (homeostatic model assessment-insulin resistance; five studies; SMD=-0.57; 95% CI: -1.17 to 0.03; I=88%). Mg supplementation appears to have a beneficial role and improves glucose parameters in people with diabetes and also improves insulin-sensitivity parameters in those at high risk of diabetes.

Serum Magnesium Concentrations in the Canadian Population and Associations with Diabetes, Glycemic Regulation, and Insulin Resistance

“…However, lower serum Mg may also contribute to poorer glycemic regulation and insulin sensitivity. Studies indicate that Mg supplementation improves glucose and insulin sensitivity parameters [49,50]. A meta-analysis of randomized controlled trials showed that Mg supplementation for over four months improved fasting glucose and HOMA-IR in diabetic and non-diabetic subjects [49].…”

“…A meta-analysis of randomized controlled trials showed that Mg supplementation for over four months improved fasting glucose and HOMA-IR in diabetic and non-diabetic subjects [49]. In another meta-analysis, Mg supplementation was shown to reduce fasting plasma glucose in diabetics and improve HOMA-IR and plasma glucose (in a 2 h oral glucose tolerance test) in persons at high risk of diabetes [50]. The mechanisms by which Mg deficiency may increase diabetes risk are poorly understood but may involve increased oxidative stress and inflammation [35,51,52].…”

Observation of Lidocaine‐suppressed Decrease of Magnesium in Salicylate‐induced Tinnitus with an Online Electrochemical System

“…Mg 2+ therapy finds wide application: Mg 2+ reduces arteriolar tone and tension, increases dilatory actions of endogenous and exogenous vasodilators, and oral magnesium therapy in patients with coronary artery disease associated with significant improvement in brachial artery endothelial function and tolerance to exercise stress testing . Mg 2+ is reported to be a necessary cofactor for several enzymes in glucose metabolism, and its deficiency has an adverse effect on insulin‐mediated glucose uptake . Increased Mg 2+ level in the cerebral fluid can ease traumatic brain injury and enhance the learning abilities, working memory, and short‐ and long‐term memory in rats .…”

CIMMYT Series on Carbohydrates, Wheat, Grains, and Health: Impact of Minerals, Phytochemicals, Specific Grain-Based Foods, and Dietary Patterns on Mild Cognitive Impairment, Alzheimer's Disease, and Parkinson's Disease

“…Proper mineral nutriture throughout life appears to be important for cognitive health, especially because magnesium can counter insulin resistance and reduce the risk of type 2 diabetes, which are known risk factors for dementia and poorer cognition (28). Studies have specifically iden-tified the association of higher magnesium intakes with reduced risk for developing MCI and low magnesium levels with increased risk (29-31).…”