The effects of magnesium and vitamin E co-supplementation on parameters of glucose homeostasis and lipid profiles in patients with gestational diabetes (Publication with Expression of Concern)

Background: Magnesium and vitamin E are known to exert multiple beneficial effects, such as anti-glycemic and anti-lipidemic properties. The aim of this study was to determine the effects of magnesium and vitamin E co-supplementation on metabolic status of women with gestational diabetes (GDM). Methods: This randomized, double-blinded, placebo-controlled trial was conducted among 60 subjects diagnosed with GDM, aged 18-40 years. Subjects were randomly allocated into two groups to receive 250 mg/day magnesium oxide plus 400 IU/day vitamin E supplements or placebo (n = 30 each group) for 6 weeks. Participants' blood samples were taken to determine their metabolic profiles. Results: Subjects who received magnesium plus vitamin E supplements had significantly lower fasting plasma glucose (beta - 5.20 mg/dL; 95% CI, - 7.88, - 2.52; P = 0.002), serum insulin levels (beta - 2.93 mu lU/mL; 95% CI, - 5.68, - 0.18; P = 0.02) and homeostasis model of assessment-insulin resistance (beta - 0.78; 95% CI, -1.42, - 0.14; P= 0.01), and higher quantitative insulin sensitivity check index (beta 0.01; 95% CI, 0.005, 0.02; P= 0.002) compared with placebo. In addition, magnesium plus vitamin E supplementation resulted in a significant reduction in serum triglycerides (beta - 50.31 mg/dL; 95% CI, - 67.58, - 33.04; P < 0.001), VLDL- (beta - 10.06 mg/dL; 95% CI, - 13.51, - 6.60; P < 0.001), total- (beta - 26.10 mg/dL; 95% CI, - 41.88, - 10.33; P= 0.004), LDL- (beta - 15.20 mg/dL; 95% CI, - 29.50, - 0.91; P= 0.03) and total-/HDL-cholesterol ratio (beta- 0.46; 95% CI, - 0.72, - 0.19; P < 0.001) compared with placebo. Magnesium and vitamin E co-supplementation did not affect HDL-cholesterol levels. Conclusions: Overall, magnesium and vitamin E co-supplementation for 6 weeks in women with GDM significantly improved glycemic control and lipid profiles, except for HDL-cholesterol levels.