Carnitine Deficiency in Chronic Kidney Disease: Pathophysiology, Clinical Implications, and Therapeutic Perspectives

Carnitine is essential for the mitochondrial transport of long-chain fatty acids and thus plays a pivotal role in energy metabolism, particularly in metabolically active organs, such as skeletal and cardiac muscle. In patients with dialysis, carnitine homeostasis is disrupted because of the reduced synthesis, impaired renal reabsorption, and carnitine loss during extracorporeal procedures. Carnitine deficiency is linked to a wide range of clinical manifestations, including muscle weakness, treatment-resistant anemia, intradialytic hypotension, mental disorder, and cardiovascular disease. This review provides a comprehensive overview of the physiological function of carnitine, elucidates the underlying mechanisms of carnitine deficiency in patients with dialysis, and explores the clinical consequences. Furthermore, the efficacy and limitations of L-carnitine supplementation in clinical practice are discussed based on the current literature. A better understanding of the pathophysiological and clinical relevance of carnitine deficiency may help facilitate personalized therapeutic strategies for patients with kidney diseases.