Nutritional status over time in hemodialysis and peritoneal dialysis

Malnutrition is a risk factor for mortality in the dialysis population. So far, prospective studies comparing the time course of nutritional status in new hemodialysis (HD) and peritoneal dialysis (PD) patients have not been published. The aims of this study were to compare the time course of nutritional status in patients who were starting HD or PD and to identify the baseline determinants of that time course. In this prospective multicenter cohort study, data were collected from 3 (baseline) to 24 mo after the start of dialysis. Repeated measures ANOVA was used to establish the time course of nutritional status. Differences were adjusted for baseline characteristics. A total of 250 consecutive new patients were included: 132 started on HD, and 118 started on PD. A univariate analysis demonstrated a decrease in serum albumin (SA) in patients who started on HD and an increase in patients who started on PD. Body fat increased in PD; LBM did not change. The protein equivalent of nitrogen appearance normalized to ideal weight decreased in PD after 1 yr. In a multivariate analysis, SA at 2 yr was 2.0 g/L (95% confidence interval [CI], 0.3 to 3.8) higher in patients who started on PD compared with patients who started on HD. The increase in body fat was 3.2 kg (95% CI, 1.6 to 4.9) higher in women who started on PD than in others. Patients who had diabetes gained 2.3 kg (95% CI, 0.6 to 4.1) more fat than patients who did not have diabetes. Kt/V(urea) did not affect the time course of nutritional status, but a higher Kt(urea) was associated with a higher SA at 24 mo. Nutritional status at the start of dialysis, gender, and diabetic status might be considered in making the choice for dialysis modality. Furthermore, providing a higher Kt(urea) may improve protein metabolism.