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.