Zinc Supplementation and the Effects on Pregnancy Outcomes in Gestational Diabetes: a Randomized, Double-blind, Placebo-controlled Trial.

Abstract

The current study was designed to determine the beneficial effects of zinc intake on biomarkers of inflammation, oxidative stress, and pregnancy outcomes among pregnant women with gestational diabetes (GDM). This randomized, double-blind, placebo-controlled clinical trial was conducted among 50 women with GDM. Patients were randomly allocated to intake either 233 mg zinc gluconate (containing 30 mg zinc) (n=25) or a placebo (n=25) for 6 weeks. Fasting blood samples were taken at the fist of the study and after 6 weeks of intervention to quantify related variables. Newborn's weight, height, head circumference, Apgar score, and hyperbilirubinemia were determined. The change in serum zinc levels after 6 weeks of supplementation was greater in women consuming zinc than in the placebo group (+8.5±13.5 vs. -3.6±16.2 mg/dL, P=0.006). Changes in serum high sensitivity C-reactive protein (hs-CRP) (-110.1±1 475.5 vs. +1 137.8±2 429.2 ng/mL, P=0.03) and plasma total antioxidant capacity (TAC) concentrations (+60.0±129.0 vs. -28.4±81.4 mmol/L, P=0.006) were significantly different between the supplemented women and placebo group. We did not find any significant effect of zinc administration on pregnancy outcomes. Taken together, zinc administration among patients with GDM was associated with decreased hs-CRP and increased TAC concentrations; however, it did not influence maternal plasma nitric oxide (NO), glutathione (GSH), malondialdehyde (MDA) levels, or pregnancy outcomes.