Prevalence, Risk Factors and Potential Protective Strategies for Hypomagnesemia in Kidney Transplant Recipients

Hypomagnesemia is the most common electrolyte disorder in kidney transplant recipients (KTR), yet its causes remain unclear. Few studies have explored its underlying factors. This study aimed to assess its prevalence and identify risk factors in KTR. We conducted a retrospective cross-sectional study in 489 outpatient KTR. Demographic, clinical, and laboratory data were collected. Univariate and multivariate logistic regression analyses were used to identify factors associated with hypomagnesemia (≤1.7 mg/dL). Hypomagnesemia was present in 50.7% of patients. Multivariate analysis identified tacrolimus [OR 2.91 (1.62-5.22)], thiazides [OR 2.23 (1.21-4.08)], cinacalcet [OR 2.31 (1.29-4.13)], serum phosphate < 3.7 mg/dL [1.99 (1.29-3.05)], serum calcium ≤ 10 mg/dL [1.99 (1.29-3.05)] and diabetes [1.94 (1.22-3.08)] as risk factors. Protective factors included SGLT2 inhibitors (SGLT2i) [OR 0.17 (0.10-0.27)] and mTOR inhibitors (mTORi) [OR 0.62 (0.38-0.98)]. Among hypomagnesemic patients, those receiving Mg²⁺ supplements had lower Mg²⁺ levels [1.54 (0.15) vs. 1.59 (0.13) mg/dL, p = 0.005] and higher fractional Mg²⁺ excretion [8.28 (4.48)% vs. 7.36 (4.19)%, p = 0.05]. Hypomagnesemia is highly prevalent in KTR. Tacrolimus, thiazides, and cinacalcet are key risk factors and, in some patients, risks and benefits of continuing these medications should be carefully weighed. In refractory cases, SGLT2i or mTORi may offer benefit.