Association Between Serum Magnesium Levels and Glycaemic Control in Patients With Type 2 Diabetes Mellitus: A Hospital-Based Cross-Sectional Study

Abstract

Background: Magnesium is an essential mineral involved in insulin signalling, glucose transport, and carbohydrate metabolism. Altered magnesium status has been reported in patients with type 2 diabetes mellitus (T2DM), but the strength of its association with glycaemic control varies across populations. Evidence from Indian tertiary-care populations remains limited and heterogeneous.

Objective: To assess the association between serum magnesium concentration and glycaemic control among patients with T2DM attending a tertiary care hospital in North India.

Methods: This hospital-based cross-sectional study included 245 adult patients with established T2DM and was conducted from January 2026 to June 2026. Demographic and clinical characteristics were recorded, and venous blood samples were analyzed for serum magnesium, fasting plasma glucose (FPG), and glycated haemoglobin (HbA1c). Serum magnesium was assessed as a continuous variable and categorized using a predefined threshold of <1.70 mg/dL. Glycaemic control was assessed primarily using HbA1c, with FPG considered a secondary measure. Continuous and categorical variables were summarized using appropriate descriptive statistics. Correlation between serum magnesium and glycaemic indices was assessed using an appropriate correlation coefficient according to data distribution.

Results: The mean age of participants was 52.18 ± 10.35 years, and 138 (56.3%) were male. The mean duration of diabetes was 8.22 ± 4.71 years. Mean serum magnesium, FPG, and HbA1c were 1.92 ± 0.17 mg/dL, 135.29 ± 43.54 mg/dL, and 7.92 ± 0.81%, respectively. Low serum magnesium (<1.70 mg/dL) was observed in 29 (11.8%) participants. Mean HbA1c was higher among participants with low magnesium than among those with magnesium ≥1.70 mg/dL (8.43 ± 0.87% vs 7.85 ± 0.78%). Serum magnesium demonstrated an inverse correlation with HbA1c (r = −0.41) and FPG (r = −0.28).

Conclusion: Lower serum magnesium concentrations were associated with poorer glycaemic indices among patients with T2DM. These findings support an association between magnesium status and glycaemic control but do not establish causality. Prospective and interventional studies are required to clarify the clinical significance of this relationship.