Association Between Levels of Magnesium and Diabetic Retinopathy in Diabetic Patients with Type 2 Diabetes Mellitus: An Updated Systematic Review and Meta-Analysis

BACKGROUND/OBJECTIVES: Magnesium is an intracellular cation that plays important roles in metabolism and insulin signaling. The evidence of association between magnesium levels and diabetic retinopathy is limited by small study effects. Therefore, this systematic review and meta-analysis aim to update the current evidence. METHODS: A comprehensive search of PubMed, ScienceDirect, Google Scholar, and Scopus was conducted from database inception to January 2026 to identify studies examining magnesium levels and diabetic retinopathy. The pooled standardized mean difference in magnesium levels between type 2 diabetic patients with retinopathy and those without retinopathy was estimated using the "meta" package in R software. RESULTS: < 0.23)]. The certainty of the generated evidence is rated as low certainty. CONCLUSIONS: This systematic review and meta-analysis conclude that magnesium levels are significantly lower in patients with diabetic retinopathy than in diabetic controls without retinopathy. A potential association between hypomagnesemia and the development of diabetic retinopathy in individuals with type 2 diabetes is suggested; therefore, the clinician may check and adjust magnesium levels in patients with type 2 diabetes mellitus.