Factors causing malnutrition in patients with chronic uremia

There is abundant evidence that patients with chronic renal failure (CRF), including those treated by hemodialysis or peritoneal dialysis, have eviden ce of malnutrition with decreased body weight and subnormal values of serum proteins (suggesting a loss of visceral protein stores). Potential causes of an abnormal nutritional status that have been identified include an inad equate intake of protein or calories, an inability to activate the metaboli c responses that are needed to achieve nitrogen and protein balance, or the presence of a disease that prevents activation of these metabolic response s or acts to stimulate the breakdown of body protein stores. Three critical metabolic responses to a limited protein intake have been identified: a re duction in the irreversible degradation of amino acids and the degradation of protein breakdown and an increase in protein synthesis in response to a meal. Metabolic acidosis blocks the first two responses and hence contribut es to malnutrition in patients with chronic uremia, Other factors that coul d contribute to malnutrition include an inadequate intake because of anorex ia or hormonal imbalances that impair protein turnover. In evaluating CRF p atients with malnutrition, the first task is to ensure an adequate intake a nd to eliminate factors that impair the ability to achieve nitrogen balance . (C) 1999 by the National Kidney Foundation, Inc.