Predictive value of dialysis adequacy and nutritional indices 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 curves on continuous ambulatory peritoneal dialysis (CAPD) and on haemodialysis (HD) are also needed, to assess adequate treatment on CAPD.


METHODS
We have evaluated the effects of age, 13 pretreatment risk factors, 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 morbidity, in a 3-year prospective study of 68 CAPD and 34 HD patients.


RESULTS
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 independent factors negatively affecting survival. On the contrary, adjusted survivals were not affected by gender, modality, other comorbid factors, normalized protein catabolic rate, or subjective global assessment of nutritional status. Persistence of residual renal function significantly 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 ( > or = 1.0 and > or = 1.7) Kt/V. On HD, adjusted survivals were similar for 1.0 < or = Kt/V < 1.2 or > or = 1.2. On CAPD, Kt/V > or = 1.96/week was associated with definitely better survival, with only one death/23 patients versus 19/45, with Kt/V < or = 1.96. Survival was not different for 1.96 < or = Kt/V < 2.03 and > or = 2.03. Normalized weekly creatinine clearance and wKt/V were positively related on CAPD (r 0.39, P < 0.01) and wKt/V = 1.96 corresponded to 58 litres of normalized weekly creatinine clearance.


CONCLUSIONS
Indices of adequacy were predictors of mortality and morbidity, both on CAPD and HD, whereas normalized protein catabolic rate and subjective global assessment of nutritional status were not. Serum albumin did not decrease during dialysis; hence its predictive effect for survival is due to the predialysis condition and not to dialysis-induced malnutrition.
Maiorca
R
R
Nephrology, University of Brescia, Italy.
Brunori
G
G
Zubani
R
R
Cancarini
G C
GC
Manili
L
L
Camerini
C
C
Movilli
E
E
Pola
A
A
d'Avolio
G
G
Gelatti
U
U
D000328:Adult; D000367:Age Factors; D000368:Aged; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007674:Kidney Diseases / Q000453:epidemiology* / Q000378:metabolism / Q000628:therapy; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009017:Morbidity; D009752:Nutritional Status / Q000502:physiology*; D010531:Peritoneal Dialysis, Continuous Ambulatory; D012044:Regression Analysis; D006435:Renal Dialysis; D012189:Retrospective Studies; D012307:Risk Factors; D015996:Survival Rate