Oost LJ, van der Heijden AAWA, Vermeulen EA, et al. - This study was undertaken to determine if serum magnesium (Mg ²⁺) was prospectively associated with macro- or microvascular complications and mediated by glycemic control (hemoglobin A1c [HbA _1c]), in type 2 diabetes (T2D). The authors examined in 4,348 candidates the correlation of serum Mg ²⁺ with macrovascular disease and mortality (acute myocardial infarction, coronary heart disease, heart failure [HF], cerebrovascular accident, and peripheral arterial disease), atrial fibrillation (AF), and microvascular complications (chronic kidney disease [CKD], diabetic retinopathy, and diabetic foot) utilizing Cox regression, adjusted for confounders. Data reported that the average baseline serum Mg ²⁺ concentration was 0.80 ± 0.08 mmol/L. Serum Mg ²⁺ concentration is inversely linked to the risk of developing HF and AF, as well as the occurrence of CKD, diabetic retinopathy, and foot complications in T2D. The association of serum Mg ²⁺ with HF and microvascular complications was partially mediated by glycemic control.