Factors contributing to catabolism in end-stage renal disease patients.

End-stage renal disease (ESRD) patients, whether they are treated with hemodialysis or continuous ambulatory peritoneal dialysis, frequently suffer from protein-energy malnutrition, which is associated with increased morbidity and mortality. The protein requirements in dialysis patients are increased compared to those of healthy individuals and nondialyzed patients with chronic renal failure. The intake of protein and energy is frequently reduced because of the underlying disease, comorbidity, psychosocial factors, and uremic anorexia (underdialysis). There are several factors in ESRD patients that may enhance protein catabolism and increase protein requirements, such as low energy intake, amino acid abnormalities, metabolic acidosis, endocrine abnormalities (insulin resistance, hyperglucagonemia, hyperparathyroidism, insensitivity to growth hormone and insulin-like growth factor-1, cardiac failure, infection and inflammation, anemia, and physical inactivity. The dialytic procedures per se may enhance protein catabolism due to dialytic losses of protein and amino acids and, in hemodialysis, an inflammatory response to blood-dialyzer interaction. The relative importance of the various factors which cause anorexia and stimulate protein catabolism is still not well understood.