The normalized protein catabolic rate is a flawed marker of nutrition in CAPD patients

Abstract

For both hemodialysis and CAPD patients nutrition has been linked to mortality. Protein calorie malnutrition is present in 20 to 40% of CAPD patients. The normalized protein catabolic rate (NPCR), has been proposed as a useful measure of dietary protein intake and ultimately nutrition. However, the NPCR value has not been consistently predictive of outcome in CAPD patients. We have performed a cross sectional study on 147 clinically stable CAPD patients, who had a mean dialysis duration 22 months, to evaluate the relationship between the NPCR and conventional markers of nutrition. The NPCR was significantly correlated with normalized models of dialysis adequacy including KT/V (urea), total weekly creatinine clearance and the dialysis index. A significant negative correlation was found between individual anthropometric measures and the NPCR. Using a composite nutritional index to nutritionally categorize our population we found a significantly higher NPCR value in the severely malnourished group. The unadjusted protein catabolic rate (PCR) was significantly correlated with individual nutritional measures and was significantly greater in the well-nourished group. The NPCR, obtained by dividing the PCR by body weight (itself a nutritional measure), is lowest in well-nourished or obese patients, and thus as a marker of nutrition may be flawed. The PCR has nutritional relevance, however, adjusting its value to take into account patient size will require prospective evaluation of the influence of small solute removal on body composition.

New Peritoneal Dialysis Model in Rats with Bilateral Nephrectomy

“…Malnutrition of patients with renal failure undergoing PD has been widely reported, [1,2] and this malnutrition appears to be induced by nutritional and metabolic issues in addition to poor appetite. [1][2][3] There are many factors responsible for this malnutrition, and thus using an experimental animal model for nutritional pathophysiological research is effective.…”

“…[1][2][3] There are many factors responsible for this malnutrition, and thus using an experimental animal model for nutritional pathophysiological research is effective. To date, several researchers have reported PD animal models [6,7] ; however, there have been few studies that have tried to clarify the effect of nutritional supply on these models, as most of these models were developed for dialysis assessment.…”

“…However, malnutrition occurs with a high frequency in uremic patients receiving PD. [1,2] Lindholm and Bergstrom reported that PD in patients with chronic renal failure is associated with metabolic and nutritional abnormalities due to the combined influences of uremia; underdialysis; glucose absorption from the dialysate, protein, and amino acid losses; poor appetite; and recurrent episodes of peritonitis. [3] Nolph et al reported that protein loss in the continuous ambulatory peritoneal dialysis (CAPD) dialysate may be up to 15 g/day, and patients are required to ingest high-protein diets.…”

Resistance to erythropoietin-stimulating agents: etiology, evaluation, and therapeutic considerations

“…Therefore, routine dietary assessment and calculation of protein nitrogen appearance (nPNA) are essential. Early detection of malnutrition warrants dietary intervention to prevent its progression into protein energy wasting [53][54][55][56]. Accuracy of anthropometric and biochemical indices for establishing protein energy wasting is jeopardized by altered body composition in CKD (Tables 1, 4) [56].…”

Role of Fermentable Carbohydrate Supplements in the Course of Uremia

“…This leads to a rejection of protein restriction with, as a result, a proposed supply in the 1 to 1.2 g/kg/day range (Bergström, 1995 ;Cianciaruso et al, 1995 ;Qureshi et al, 1998 ;Antunes et al, 2010). However, it is still uncertain whether this policy is enough in order to equilibrate the N balance in these patients since there is a proportional relationship between the protein supply and the rate of N catabolism as it is estimated by the PCR (protein catabolism rate) (Movilli et al, 1993 ;Harty et al, 1994;Fouque et al, 2011a). The protein-caloric undernutrition observed in dialysis patients is often linked to a deficient supply (Ikizler et al, 1995 ;Pollock et al, 1997, Kalantar-Zadeh, 2003, which is itself often linked to a depressed appetite (Bergström, 1995;Van Der Eijk & Farinelli, 1997).…”