Uraemic sarcopenia: aetiology and implications

The term uraemic myopathy has been used loosely to describe the skeletal muscle abnormalities in uraemic patients. However, it does not fully explain the observed abnormalities as recent research has documented a normal skeletal muscle physiology in the presence of reduced muscle force, selective structural changes and significant muscle wasting. Ageing is associated with sarcopenia (muscle wasting) and an increase in the prevalence of chronic kidney disease (CKD), which accelerates the normal physiological muscle wasting. Similar to sarcopenia, muscle wasting in uraemic patients appears to be the hallmark of the disease and its aetiology is multifactorial with hormonal, immunologic and myocellular changes, metabolic acidosis, reduced protein intake and physical inactivity. Uraemic sarcopenia presents a high probability for morbidity and mortality and consequently a high priority for muscle wasting prevention and treatment in these patients. Perhaps, the use of the term 'uraemic sarcopenia' would provide recognition by the renal community for this devastating problem. The purpose of this review is to relate the findings of the recent publications that describe abnormalities in uraemic skeletal muscle to the possible pathogenesis of muscle wasting and its consequences in patients with CKD.