Magnesium Without Insulin May Benefit Pregnant Patients With Gestational Diabetes

Magnesium supplementation may be effective in treating patients with gestational diabetes without taking insulin treatment, according to research published in the European Journal of Obstetrics & Gynecology and Reproductive Biology.¹

Low plasma magnesium concentration is often reported in pregnant women with gestational diabetes, regarded as the most common metabolic disorder during pregnancy. Although previous studies have demonstrated positive effects associated with magnesium supplementation in patients with gestational diabetes, the efficacy of the practice is not entirely understood.

In conducting their meta-analysis, investigators sought to confirm the efficacy of magnesium supplementation for glycemic control and fetal outcomes among pregnant patients with gestational diabetes.

“Several studies explored the efficacy of magnesium supplementation for patients with gestational diabetes, but its efficacy was not well established,” study authors noted. “Therefore, this meta-analysis of randomized controlled clinical trials (RCTs) aimed to evaluate the effectiveness of magnesium supplementation on glycemic status and pregnant outcomes for gestational diabetes.”

To select studies for their meta-analysis, investigators parsed several databases using the key words “magnesium” and “gestational diabetes.” Inclusion criteria required that the study designs were RCT, women were given a gestational diabetes diagnosis, and intervention treatments measured magnesium supplementation versus placebo.

The primary outcome was fasting plasma glucose, and the secondary outcomes were homeostasis model assessment of insulin resistance, serum insulin, preterm delivery, macrosomia (>4000 g) and BMI change.

Although the results of the meta-analysis, which ultimately included 5 RCTs and 266 women, demonstrated that magnesium supplementation was able to decrease fasting glucose levels and improve insulin resistance, they did not show an influence on serum insulin preterm delivery, macrosomia (>4000 g) or BMI change. Other notable results revealed that magnesium-vitamin E co-supplementation increased total antioxidant capacity by 5.66 ± 0.86% among patients.

Investigators did not observe any significant heterogeneity among the RCTs but noted that several factors could have contributed to bias. These included: the combination use of magnesium supplements and vitamin E in some RCTs; variations in the duration and severity of gestational diabetes across RCTs; variations in gestational ages at which patients began taking magnesium supplements.

On behalf of their results, investigators noted that since the effects of magnesium supplementation on glycemic control did not translate into pregnancy outcomes, more research is needed on the issue. They noted further that studying larger patient samples than what was used in the current study is needed to confirm their findings.

“Maternal insulin resistance in gestational diabetes may lead to increased placental size and affect fetal growth, while sufficient glycemic control in these patients can improve pregnancy outcomes,” study authors wrote. “However, in this meta-analysis, the beneficial effect of magnesium supplements on glycemic control was not translated to the pregnant outcomes, and more studies should focus on this issue.”

Reference

1. Luo L, Zhang Y, Wang H, Chen D, Li L. The efficacy of magnesium supplementation for gestational diabetes: A meta-analysis of randomized controlled trials. Eur J Obstet Gynecol Reprod Biol. Published online December 12, 2023. doi:10.1016/j.ejogrb.2023.12.014