A systematic review and meta-analysis of randomized controlled trials on the effects of magnesium supplementation on insulin sensitivity and glucose control

• Published in: Pharmacological research Vol. 111; pp. 272 - 282
• Main Authors: Simental-Mendía, Luis E., Sahebkar, Amirhossein, Rodríguez-Morán, Martha, Guerrero-Romero, Fernando
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Ltd 01-09-2016
• Subjects: Adult; Aged; Aged, 80 and over; Biomarkers - blood; Blood Glucose - drug effects; Blood Glucose - metabolism; Diabetes Mellitus - blood; Diabetes Mellitus - diagnosis; Diabetes Mellitus - drug therapy; Dietary Supplements; Female; Glucose control; Glycated Hemoglobin A - metabolism; Humans; Hypoglycemic Agents - therapeutic use; Insulin - blood; Insulin Resistance; Insulin sensitivity; Magnesium; Magnesium - administration & dosage; Male; Meta-analysis; Middle Aged; Randomized Controlled Trials as Topic; Time Factors; Treatment Outcome; Magnesium; Insulin sensitivity; Glucose control; Meta-analysis
• ISSN: 1043-6618; 1096-1186
• DOI: 10.1016/j.phrs.2016.06.019

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A systematic review and meta-analysis was conducted to evaluate the effect of oral magnesium supplementation on insulin sensitivity and glucose control in both diabetic and non-diabetic individuals.
PubMed-Medline, SCOPUS, Web of Science and Google Scholar databases were searched (from inception to November 25, 2015) to identify RCTs evaluating the effect of magnesium on insulin sensitivity and glucose control. A random-effects model and generic inverse variance method were used to compensate for the heterogeneity of studies. Publication bias, sensitivity analysis, and meta-regression assessments were conducted using standard methods.
The impact of magnesium supplementation on plasma concentrations of glucose, glycated hemoglobin (HbA1c), insulin, and HOMA-IR index was assessed in 22, 14, 12 and 10 treatment arms, respectively. A significant effect of magnesium supplementation was observed on HOMA-IR index (WMD: ⿿0.67, 95% CI: ⿿1.20, ⿿0.14, p=0.013) but not on plasma glucose (WMD: ⿿0.20mmol/L, 95% CI: ⿿0.45, 0.05, p=0.119), HbA1c (WMD: 0.018mmol/L, 95% CI: ⿿0.10, 0.13, p=0.756), and insulin (WMD: ⿿2.22mmol/L, 95% CI: ⿿9.62, 5.17, p=0.556). A subgroup analysis comparing magnesium supplementation durations of <4 months versus ⿥4 months, exhibited a significant difference for fasting glucose concentrations (p<0.001) and HOMA-IR (p=0.001) in favor of the latter subgroup.
Magnesium supplementation for ⿥4 months significantly improves the HOMA-IR index and fasting glucose, in both diabetic and non-diabetic subjects. The present findings suggest that magnesium may be a beneficial supplement in glucose metabolic disorders.