Protein and amino acid metabolism in patients undergoing continuous ambulatory peritoneal dialysis (CAPD)

Several factors contribute to impaired nutritional status in patients undergoing CAPD. The protein loss into the dialysate varies between 5-15 g per day; during peritonitis protein loss increases by 50-100%. The loss of free amino acids during CAPD is of the same magnitude as under hemodialysis. The observed plasma amino acid abnormalities in CAPD patients probably reflect metabolic derangements in uremia, rather than depletion due to dialysate amino acid loss. Sustained hyperinsulinemia in CAPD patients also may contribute to reduced plasma amino acid concentrations. A further factor contributing to nutritional problems in CAPD is a decreased protein intake. Dietary protein intake should exceed 1.2 g/kg/day during long-term CAPD treatment to maintain nitrogen equilibrium. Total energy intake may exceed 35 kcal/kg/day.