PROTEIN AND CALORIC MALNUTRITION IN CHRON IC-HEMODIALYSIS PATIENTS (CHD) - VALIDITY OF PROTEIN CATABOLIC RATE (PCR) DETERMINATION

In a cross-sectional study we evaluated the nutritional status of 29 s table patients undergoing thrice,weekly CHD (18 M, 11 F, mean age 49 /- 17 yr, 68 +/- 6 months on CHD), and the validity of PCR determinati on was verified. Nutritional status was assessed by anthropometric mea surements (relative body weight, triceps skin-fold thickness and arm m uscle circumference), biochemical methods (serum proteins, transferrin , and prealbumin concentration), urea kinetic studies (PCR was obtaine d according to Sargent's formula, and Watson equation was used to calc ulate urea distribution volume), and dietary intake was recorded durin g a 3-day period. Somatic composition (anthropometric measurements) wa s reduced in 62 % patients indicating that malnutrition is more widesp read than body weight measurements alone indicate (reduced only in 38 % of patients). In contrast, the normal serum protein results, indicat e that these parameters have a low sensitivity and specificity for the detection of malnutrition. A greater reduction of energy intake (26,8 +/- 11,9 Kcalk/d) than protein intake (1,02 +/- 0,4 g/k/d) was observ ed (figure 1). Of patients 55 (81 %) ate less protein and calories res pectively, than recomended. A negative relationship between age and pr otein intake (r = -0, 65, p < 0,01) (figure 2) was observed.PCR was a good index of protein intake (r = 0, 77, p < 0,01) (figure 3). The cap acity of PCR in identifying patients with protein intake higher and lo wer than 1 g/kg/day, showed a sensitivity of 92 %, an specificity of 8 1 % and a predictive value of 80 % (figure 4). To summary, nutritional abnormalities are frequently found, even in apparently clinically sta ble CHD patients. The depletion of both protein and energy stores, whi le serum proteins are not marked decreased, is characteristic of the m arasmus form of malnutrition. Calorie, more than protein malnutrition, is a major aspect of their wasting. Undernutrition appeared more comm only in older CHD patients. Although PCR provided a reliable index of protein intake, some degree of nitrogen imbalance appeared in 14 % of apparently clinically stable CHD patient. Considering these circumstan ces, it seems very important a direct evaluation of dietary intake, to monitor the energetic and nitrogen balance of CHD patients.