Effect of zinc supplementation on glycemic biomarkers: an umbrella of interventional meta-analyses

Abstract

Background Several studies have evaluated the effects of zinc supplementation on glycemic biomarkers in humans and have demonstrated varying results. We systematically evaluated the literature and performed an umbrella meta-analysis of the effects of zinc supplementation on type 2 diabetes biomarkers. Methods A comprehensive literature search was conducted in the following databases; PubMed, Embase, Embase, Cochrane Library, Scopus, and Web of Science for studies published up to March 10, 2024. Results Zinc supplementation was effective in reducing serum FBS (WMD: − 13.58, 95% CI: − 17.38, − 9.77; p < 0.001; SMD: − 0.52, 95% CI − 0.79, − 0.25; p = < 0.001), insulin (SMD: − 0.67, 95% CI − 0.96, − 0.38; p < 0.001), HOMA-IR levels (WMD − 0.52, 95% CI − 0.66, − 0.38; p < 0.001; SMD: − 0.78, 95% CI − 1.02, − 0.42; p < 0.001), and HbA1c (WMD: − 0.35, 95% CI − 0.43, − 0.27; p < 0.001). Conclusion Zinc supplementation significantly reduced FBS, HOMA-IR, insulin and HbA1c. These findings suggest that zinc is potentially an effective complementary intervention to improve type 2 diabetes biomarkers.