PREDICTIVE VALUE OF DIALYSIS ADEQUACY AND NUTRITIONAL INDEXES FOR MORTALITY AND MORBIDITY IN CAPD AND HD PATIENTS - A LONGITUDINAL-STUDY

Background. The effects of dialysis inadequacy on patient survival and nutritional status and that of malnutrition on survival have not been clearly assessed. Studies comparing dose/mortality and morbidity curv es on continuous ambulatory peritoneal dialysis (CAPD) and on haemodia lysis (HD) are also needed, to assess adequate treatment on CAPD. Meth ods. We have evaluated the effects of age, 13 pretreatment risk factor s, serum albumin, transferrin, normalized protein catabolic rate, Kt/V , normalized weekly creatinine clearance, residual renal function and subjective global assessment of nutritional status on survival and mor bidity, in a 3-year prospective study of 68 CAPD and 34 HD patients. R esults. Survivals did not differ for CAPD and HD patients. In the Cox hazard regression model, age, peripheral vasculopathy, serum albumin < 3.5 g/dl and Kt/V < 1.0/treatment on HD and < 1.7/week on CAPD were i ndependent factors negatively affecting survival. On the contrary, adj usted survivals were not affected by gender, modality, other comorbid factors, normalized protein catabolic rate, or subjective global asses sment of nutritional status. Persistence of residual renal function si gnificantly improved survival. Observed and adjusted survival did not significantly differ for CAPD and HD patients with either low (HD, < 1 .0/treatment; CAPD, < 1.7/week) or high (greater than or equal to 1.0 and greater than or equal to 1.7) Kt/V. On HD, adjusted survivals were similar for 1.0 less than or equal to Kt/V < 1.2 or greater than or e qual to 1.2. On CAPD, Kt/V greater than or equal to 1.96/week was asso ciated with definitely better survival, with only one death/23 patient s versus 19/45, with Kt/V less than or equal to 1.96. Survival was not different for 1.96 less than or equal to Kt/V < 2.03 and greater than or equal to 2.03. Normalized weekly creatinine clearance and wKt/V we re positively related on CAPD (r 0.39, P < 0.01) and wKt/V = 1.96 corr esponded to 58 litres of normalized weekly creatinine clearance. Concl usions. Indices of adequacy were predictors of mortality and morbidity , both on CAPD and HD, whereas normalized protein catabolic rate and s ubjective global assessment of nutritional status were not. Serum albu min did not decrease during dialysis; hence its predictive effect for survival is due to the predialysis condition and not to dialysis-induc ed malnutrition.