The influence of zinc supplementation on metabolic status in gestational diabetes: a meta-analysis of randomized controlled studies

Abstract

Introduction Zinc supplementation has emerged as an important approach to improve metabolic status in gestational diabetes. However, its use has not been well established. We conduct a systematic review and meta-analysis to evaluate the efficacy of zinc supplementation to improve metabolic status for gestational diabetes. Methods PubMed, Embase, and the Cochrane Central Register of Controlled Trials are searched. Randomized controlled trials (RCTs) assessing the influence of zinc supplementation (or its combination) versus placebo on metabolic status of gestational diabetes are included. Two investigators independently have searched articles, extracted data, and assessed the quality of included studies. Meta-analysis is performed using the random-effect model. Results Five RCTs involving 263 patients are included in the meta-analysis. Compared with control intervention for gestational diabetes, zinc supplementation is associated with significantly reduced FPG (std. MD = −0.52; 95% CI = −0.82 to −0.21; p = .0008), insulin (std. MD = −0.68; 95% CI = −0.98 to −0.37; p < .0001), HOMA-IR (std. MD = −0.77; 95% CI = −1.08 to −0.45; p < .00001), and increased QUICKI (std. MD = 0.58; 95% CI = 0.28–0.89; p = .0002) as well as zinc change (std. MD = 0.90; 95% CI = 0.58–1.21; p < .00001), but has no remarkable influence on LDL-cholesterol (std. MD = −0.13; 95% CI = −0.43–0.17; p = .40), and total cholesterol (std. MD = −0.28; 95% CI = −0.63–0.07; p = .11). Conclusions Zinc supplementation is effective to decrease FPG, insulin, HOMA-IR and improve QUICKI in gestational diabetes, but has no significant impact on LDL-cholesterol and total cholesterol.