Uremic Sarcopenia

"Uremic sarcopenia" refers to a progressive decrease in muscle mass, strength, and function despite normal skeletal muscle physiology in patients with chronic kidney disease (CKD). Sarcopenia involves multiple risk factors, comprising immunological changes, hormonal, metabolic acidosis, reduced protein intake, and physical inactivity. All these risk factors, along with complex pathophysiological mechanisms including ubiquitin, insulin/IGF-1, myostatin, and indoxyl sulfate, activate downstream pathways that ultimately increase muscle degradation while reducing muscle regeneration. Uremic sarcopenia not only affects the quality of life but also increases the risk of morbidity and mortality in patients with CKD. Of all the treatment modalities, aerobic and resistance exercise have shown prevention and reduced rate of muscle degeneration. A variety of pharmacological agents have been tried to target different steps in the known pathogenetic pathways, including the use of androgens and anabolic steroids, correction of vitamin D deficiency, use of growth hormone supplementation, and suppression of the ubiquitin pathway. Though some of these techniques have had beneficial results in animal experiments, human trials are still sparse. This review article relates to recent publications that describe the abnormalities in skeletal muscle that primarily leads to muscle wasting and its consequences in patients with CKD.