ETIOLOGY OF SEVERE MALNUTRITION - RESULTS OF AN INTERNATIONAL CROSS-SECTIONAL STUDY IN CONTINUOUS AMBULATORY PERITONEAL-DIALYSIS PATIENTS

In an international cross-sectional study of 224 continuous ambulatory peritoneal dialysis (CAPD) patients, 59% were well nourished but 8% had severe malnutrition. To investigate factors that might underlie the severe malnutrition, we analyzed these data further. Forty-one percent of well-nourished patients had no residual renal function (RRF). Compared with well-nourished patients who had RRF, patients with no RRF received more dialysis, but not enough to compensate completely for loss of RRF. In addition, well-nourished patients with no RRF had a lower protein catabolic rate (PCR) than patients with RRF, although somatic and visceral protein stores were similar in the two groups. Compared with well-nourished patients with no RRF, severely malnourished patients, 94% of whom had no RRF, were prescribed and were receiving a lower total volume of dialysate. The latter had actual body weights (ABWs) that were considerably less than their desirable body weights (DBWs) due to recent losses of somatic protein and fat stores, whereas well-nourished patients were at or near their DBWs. Urea clearance, normalized to 0.58 X ABW, was similar in well-nourished and severely malnourished patients with no RRF, but was significantly decreased in severely malnourished patients when normalized to 0.58 X DBW. This suggests that in severely malnourished patients no compensation had been made for their loss of RRF, and they may have been chronically underdialyzed. The PCR, normalized to ABW, was similar in well-nourished and severely malnourished patients. Thus, the severely malnourished patients were not eating the additional protein that would have been required to restore good protein status. Other factors such as diabetes, frequency of peritonitis, and peritoneal protein losses were similar in well-nourished and severely malnourished groups. The results suggest that the failure to compensate for loss of RRF can lead to malnutrition, whereas increasing the dialysis dose as RRF decreases can help to maintain good nutritional status. © 1994, National Kidney Foundation. All rights reserved. All rights reserved.