Dialysis vintage, body composition, and survival in peritoneal dialysis patients.

Abstract

The relationship between dialysis vintage (length of time on dialysis), body composition, and survival has been reported in hemodialysis patients. In the present study, we examined the association ofdialysis vintage with body composition and survival in peritoneal dialysis (PD) patients. At enrollment, body composition in 65 PD patients was determined by bioelectrical impedance analysis. Patients (mean age at enrollment: 54 years) were followed for up to 11 years maximum. At enrollment, the mean, median, and maximum dialysis vintages were 51, 34, and 261 months respectively. After adjusting for age, race, sex, and diabetes status, dialysis vintage was indirectly correlated (partial correlation coefficients) with body weight (r = -0.40, p = 0.001), body mass index (r = -0.40, p = 0.002), body surface area (r = -0.39, p = 0.002), body cell mass (r = -0.39, p = 0.002), total body fat weight (r = -0.30, p = 0.02), and fat percentage of body weight (r = -0.31, p = 0.018), and directly correlated with extracellular mass to body cell mass ratio (r = 0.27, p = 0.039). The observed cumulative survival was significantly higher (p = 0.007) in patients with a dialysis vintage at enrollment of 35 months or less, than in patients with dialysis vintage at enrollment of more than 35 months. In the multivariate Cox regression analysis, adjusting for age, race, sex, and diabetes, dialysis vintage at enrollment remained an independent predictor of mortality (relative risk: 1.010; p = 0.002). Increase in relative risk of death with increasing dialysis vintage may be partly explained by the association of vintage with unfavorable changes in body composition and the nutrition status of patients over time.