ALBUMIN SYNTHESIS, CATABOLISM AND DISTRIBUTION IN DIALYSIS PATIENTS

Hypoalbuminemia predicts mortality in hemodialysis patients with end-s tage renal disease (ESRD) and is assumed to result from malnutrition. We report here that plasma albumin levels are reduced significantly in both hemodialysis and peritoneal dialysis (PD) patients compared to n ormal subjects. Among hemodialysis patients with normal albumin levels (the upper quartile of albumin distribution), albumin synthesis rates , fractional catabolic rates, and distribution between the vascular an d extravascular pool are normal, suggesting that ESRD per se does not derange albumin metabolism. Albumin synthesis is reduced in hemodialys is patients who are hypoalbuminemic, but the fractional albumin catabo lic rate decreases normally, and albumin distribution between the vasc ular and extravascular space remains normal, suggesting that hypoalbum inemia results primarily from decreased synthesis. Using multiple line ar regression analysis, the strongest correlates to plasma albumin con centration in 115 hemodialysis patients were the plasma level of the a cute-phase C-reactive protein (CRP) and the normalized protein catabol ic rate (PCRn). These two independent: predictors of plasma albumin co ncentrations are markers of inflammation and of protein intake, respec tively. CRP levels correlate more strongly with albumin concentration than does low PCRn. Activity of the acute-phase response is an importa nt predictor of low plasma albumin concentration in hemodialysis patie nts independently of nutritional factors. External loss of albumin in the dialysate is an additional factor that contributes significantly t o hypoalbuminemia in PD patients.