Improvement in Serum Magnesium Levels With Sodium-Glucose Cotransporter 2 Inhibitors

Sodium-glucose cotransporter 2 inhibitors (SGLT2i) are associated with a modest but significant increase in serum magnesium levels. This report describes improvement in serum magnesium and associated symptoms after initiating SGLT2i therapy in a patient with refractory hypomagnesemia. A 58-year-old woman presented with persistent hypomagnesemia refractory to oral magnesium supplements. She had history of type 2 diabetes mellitus, hypothyroidism, fibromyalgia, and degenerative disk disease. The cause of hypomagnesemia was attributed to excessive renal losses. Laboratory investigations revealed serum magnesium of 1.2 mg/dL with fractional excretion of magnesium of 8.9%. She was started on empagliflozin 10 mg daily. Within 4 weeks of therapy, her serum magnesium level corrected with symptomatic improvement, which was sustained a few weeks later. Subsequently, her oral magnesium supplements dose was reduced. SGLT2i has been shown to improve magnesium levels in patients with urinary magnesium wasting. Several mechanisms have been postulated, but the exact physiology remains unknown. SGLT2i have been efficacious for glycemic control, renal protection, decreasing the risk of atherosclerotic cardiovascular disease events, and cardiac mortality in patients with diabetes. In addition, renal and cardiac benefits are also demonstrated in patients without diabetes. This observation demonstrates that SGLT2i can improve the management of patients with otherwise intractable hypomagnesemia.