Magnesium has been introduced as one of the micronutrients with several metabolic benefits, mainly anti-inflammatory properties. The aim of this study was to evaluate the effects of magnesium supplementation on gene expression of inflammatory markers, vascular endothelial growth factor (VEGF), and pregnancy outcomes in women diagnosed with gestational diabetes mellitus (GDM). This randomized, double-blinded, placebo-controlled trial was conducted among 36 women, aged 18-40 years old, diagnosed with GDM. Study participants were randomly allocated into two groups to receive either 250 mg/day magnesium oxide (n = 18) or placebo (n = 18) for six weeks. Gene expression related to inflammatory markers and VEGF was assessed using peripheral blood mononuclear cells (PBMCs) of women with GDM, via RT-PCR method. Quantitative results of RT-PCR demonstrated that magnesium supplementation downregulated gene expression levels of interleukin-8 (IL-8) (P = 0.03) and tumor necrosis factor-α (TNF-α) (P = 0.006) and upregulated gene expression levels of transforming growth factor beta (TGF-β) (P = 0.03) in PBMCs of women with GDM, compared with placebo. Magnesium supplementation did not significantly affect gene expression of IL-1 and vascular endothelial growth factor. Additionally, magnesium administration resulted in a lower incidence of newborn hyperbilirubinemia (11.1% versus 44.4%, P = 0.02) and newborn hospitalization (11.1% versus 44.4%, P = 0.02) compared with placebo. Overall, magnesium supplementation for six weeks significantly decreased gene expression levels of IL-8 and TNF-α, and increased TGF-β in women with GDM. Therefore, magnesium supplementation might be recommended to decrease metabolic complications in women with GDM, due to its beneficial effects on gene expression of inflammatory markers.
Keywords: gene expression; gestational diabetes; inflammation; magnesium; pregnancy outcomes.