The Association Between Serum Magnesium Levels and Gestational Diabetes Mellitus: a Systematic Review and Meta-Analysis.

Observational studies suggest that the potential role of magnesium remains controversial in gestational diabetes mellitus (GDM). This meta-analysis aims to consolidate the available information from observational studies that have focused on the relationship between magnesium levels and GDM. A systematic and comprehensive literature search was conducted in PubMed, Embase, Web of Science, CNKI, and Wanfang databases. Data were extracted independently by two investigators. Standardized mean differences (SMD) and 95% confidence intervals (CIs) were used to summarize the circulating magnesium levels (CI). This meta-analysis included a total of 17 studies involving 2858 participants including 1404 GDM cases and 1454 healthy controls, which showed that magnesium levels were significantly lower in GDM compared to healthy controls (SMD: - 0.35; 95% CI: - 0.62, - 0.07, P = 0.013). Likewise, the same phenomenon was observed in the third trimester (SMD =  - 1.07; 95% CI: - 1.84 to - 0.29, P = 0.007). Other subgroup analyses revealed that this trend of decreasing magnesium concentration was only observed in Europeans (SMD =  - 0.64; 95% CI: - 0.90, - 0.38, P < 0.0001). This meta-analysis revealed that serum magnesium levels were lower in patients with GDM than in healthy pregnant women, and this discrepancy was most pronounced in European populations and during the third trimester. Nevertheless, current evidence suggests that circulating magnesium deficiency is associated with gestational diabetes; the challenge for the future is to further elucidate the possible benefits of preventing gestational diabetes through magnesium supplementation.