Ionized and total magnesium levels and health outcomes in patients with type 2 diabetes mellitus

Magnesium (Mg) is a vital trace element in cellular processes, including glucose metabolism and insulin action. This study aimed to assess the prevalence of dysmagnesemia among patients with type 2 diabetes mellitus (T2DM) and its relationship with glycaemic control and diabetic complications. A cross-sectional study was conducted at Sultan Qaboos University Hospital (SQUH) from August 1, 2023, to April 30, 2024. The study included adult patients with T2DM treated with oral hypoglycemic agents (OHA), insulin, glucagon-like-peptide 1 (GLP-1) injections or their combinations. Both ionized (iMg) and total (tMg) concentrations were measured and the iMg/tMg ratio was calculated. A total of 329 patients with T2DM of which179 females (54.4%), were studied. Hypomagnesemia was observed in 10.0% based on iMg concentrations and 56.2% based on tMg concentrations, while hypermagnesemia was observed in 11.85% (iMg) and 1.82% (tMg). A positive correlation was found between iMg and tMg (r = 0.589, p < 0.01). Hypermagnesemia was associated with higher serum creatinine concentrations (p < 0.01) and lower estimated glomerular filtration rate (eGFR) (p = 0.026). An iMg/tMg ratio above 80% was associated with elevated HbA1c levels, while ratios below 60% were associated with diabetic retinopathy and hypertension. Dysmagnesemia was common among patients with T2DM. The iMg/tMg ratio was associated with diabetic control and presence of complications. The iMg/tMg ratio could be further studied as a potential marker for glycemic control.