Factors causing catabolism in maintenance hemodialysis patients.

Malnutrition is common in maintenance hemodialysis (HD) patients who are frequently anorectic. The protein requirements in HD patients are increased compared with nonuremics. Factors which tend to increase the protein requirements are: low energy intake, metabolic acidosis, leading to enhanced catabolism of branched-chain amino acids in muscle, and dialytic losses of amino acids and glucose. In addition, the HD procedure results in inhibition of muscle and whole body protein synthesis, and induces an inflammatory response (blood membrane interaction, endotoxins) leading to enhanced muscle protein breakdown. The relative importance of the various factors leading to enhanced net protein catabolism in HD patients remains to be elucidated.