Effects of counteracting measures on muscle contraction determinants in CKD: what muscle biopsy studies tell us?

Chronic kidney disease (CKD) is characterized by muscle atrophy, fatigue intolerance and other indicators of muscle dysfunction, collectively termed uremic myopathy, with devastating consequences in overall health status and mortality rates. Although many factors such as metabolic acidosis, substrate availability and neuropathy have been implicated, the mechanisms underlying uremic myopathy have not yet been fully understood. However, there is clear evidence that muscle specific factors such as fiber atrophy, fiber type alterations and mitochondrial abnormalities are presented in muscle biopsies of CKD patients and can negatively affect muscle contraction. Counteracting measures such as exercise and nutritional interventions have been shown to improve muscle performance, health indices and overall quality of life of CKD patients. However, little is known about their effects on factors affecting muscle contraction at the muscle biopsy level and therefore on the mechanisms underlying uremic myopathy. The current systematic review aims to summarize the effects of recent interventional studies on muscle contraction determinants based on muscle biopsies of human patients.