Leonor Fayos de Arizon

It is now widely recognized that maintaining magnesium (Mg) homeostasis is critical for health, especially in the context of chronic kidney disease (CKD). Patients with CKD commonly develop hyperphosphatemia and secondary hyperparathyroidism, which are controlled by therapies targeting intestinal phosphate absorption and circulating calcium levels or by modulating parathyroid calcium sensing. Notably, Mg supplementation may provide dual benefits by promoting bone formation and maintaining normal mineralization with slightly elevated serum levels. Importantly, low Mg levels are associated with mortality risk in CKD, highlighting the importance of maintaining adequate serum Mg levels in these patients. Particularly, kidney transplant (KT) patients have lower circulating Mg levels, likely due to interactions with immunosuppressive treatments. Sodium-glucose co-transporter 2 (SGLT2) inhibitors have shown survival benefits in CKD and increased serum Mg levels, suggesting that Mg regulation may contribute to these outcomes. Overall, Mg plays a key role in CKD-associated mineral and bone disorders (CKD-MBD). Thus, understanding the mechanisms underlying the alteration of Mg homeostasis in CKD could improve clinical outcomes. This review summarizes the basic and clinical studies demonstrating (1) the key actions of Mg in CKD-MBD, including secondary hyperparathyroidism and bone abnormalities; (2) the distinctive profile of KT patients for Mg homeostasis; and (3) the interaction between commonly used drugs, such as SGLT2 inhibitors or immunosuppressive treatments, and Mg metabolism, providing a broad understanding of both the key role of Mg in the context of CKD and the treatments that should be considered to manage Mg levels in CKD patients.

Rhabdomyolysis is a major cause of acute kidney failure. The etiology is diverse, from full-blown crush syndrome to less frequent causes, such as metabolic myopathy. We describe the case of a 35-year-old male with a history of intermittent myalgias who was admitted to hospital with acute renal failure secondary to rhabdomyolysis. Moderate to intense diffuse uptake of technetium-99m was seen in soft tissues at scintigraphy. The diagnosis of metabolic myopathy was confirmed after careful workup and genetic testing.