NUTRITIONAL-STATUS AS A PREDICTOR OF MORBIDITY AND MORTALITY IN MAINTENANCE DIALYSIS PATIENTS

Many epidemiologic studies indicate that protein-energy malnutrition i s a strong predictor of morbidity and mortality in maintenance hemodia lysis and chronic peritoneal dialysis patients. Those parameters of pr otein-energy malnutrition that have been most clearly associated with morbidity or mortality include serum albumin, dietary protein intake a s indicated by the protein equivalent of total nitrogen appearance (PN A, also referred to as PCR), and the predialysis serum urea nitrogen. In large scale clinical surveys, low predialysis serum creatinine, cho lesterol, potassium, phosphorus, calcium, and bicarbonate also correla te with increased mortality rates in maintenance hemodialysis patients . These correlations may reflect an association between dietary intake and mortality. The paucity of data correlating energy intake or body composition (e.g., total body protein or nitrogen, skeletal muscle mas s, total body fat) with clinical outcome may reflect the difficulty of obtaining these data in large scale prospective or retrospective anal yses. The correlation between protein-energy malnutrition and increase d morbidity and mortality rates does not prove that a higher protein a nd/or energy intake or a more optimal body composition will improve th e patient's outcome. Prospective, randomized studies will be necessary to examine this question. However, two retrospective analyses of the effect of intradialytic parenteral nutrition on mortality rates in mai ntenance hemodialysis patients are consistent with the thesis that inc reased nutrient intake will reduce mortality in maintenance hemodialys is patients. Methods for assessing protein-energy nutritional status a re discussed. There are essentially no data indicating that the more c omplicated and expensive techniques for nutritional assessment have im portant advantages over the more simple methods for the clinical manag ement of maintenance dialysis patients.