Oral Magnesium Supplementation for Treating Glucose Metabolism Parameters in People with or at Risk of Diabetes: A Systematic Review and Meta-Analysis of Double-Blind Randomized Controlled Trials
What this study found
In diabetes, magnesium supplementation significantly reduced fasting plasma glucose (11 studies; SMD −0.43; p=0.02); HbA1c and fasting insulin or HOMA-IR did not show significant improvements. In people at high risk of diabetes, magnesium significantly improved fasting plasma glucose (11 studies; SMD −0.34; p<0.0001), 2‑hour OGTT glucose (3 studies; SMD −0.35), and HOMA-IR (9 studies; SMD −0.23; p=0.028); HbA1c and serum insulin largely unchanged. Magnesium was generally well tolerated with gastrointestinal side effects (diarrhea) and no severe adverse events reported. Conclusion: Magnesium…
- Study & population
- Adults with diabetes (mostly type 2; some with type 1) or at high risk of diabetes; randomized, double-blind, placebo-controlled trials; parallel designs (majority) with some crossover designs; follow-up 4–48 weeks.
- Intervention
- Oral magnesium supplementation; predominantly magnesium oxide; dosage not reported; duration 4–48 weeks (diabetes trials median ~12 weeks; high-risk trials median ~14 weeks); taken orally.
- Key limitation
- Small-sample, short-duration RCTs with varied magnesium dosages and formulations leading to high heterogeneity; evidence mainly from type 2 diabetes; limited data on other diabetes types; inconsistent effects across outcomes (HbA1c and insulin); some crossover designs; follow-up durations varied.
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Open PDFOriginal abstract
There is a large and growing body of literature focusing on the use of oral magnesium (Mg) supplementation for improving glucose metabolism in people with or at risk of diabetes. We therefore 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 a placebo. Several databases were searched investigating the effect of oral Mg supplementation vs placebo in patients with diabetes or conditions at high risk of diabetes. Data were reported as standardized mean differences (SMDs) with their 95% confidence intervals (CIs) using follow-up data of glucose and insulin-sensitivity parameters. Compared with placebo, Mg supplementation reduced fasting plasma glucose in people with diabetes. In people at high risk of diabetes, Mg supplementation significantly improved plasma glucose per se, and after a 2 h oral glucose tolerance test. Furthermore, Mg supplementation demonstrated an improvement in insulin sensitivity markers. In conclusion, Mg supplementation appears to have a beneficial role and improves glucose parameters in people with diabetes. Moreover, our work indicates that Mg supplementation may improve insulin-sensitivity parameters in those at high risk of diabetes.