Body size and longitudinal body weight changes do not increase mortality in incident peritoneal dialysis patients of the Brazilian peritoneal dialysis multicenter study

OBJECTIVES: To determine the roles of body size and longitudinal body weight changes in the survival of incident peritoneal dialysis patients. PATIENTS AND METHODS: Patients (n = 1911) older than 18 years of age recruited from 114 dialysis centers (Dec/ 2004-Oct/2007) and participating in the Brazilian Peritoneal Dialysis Multicenter Cohort Study were included. Clinical and laboratory data were collected monthly (except if the patient received a transplant, recovered renal function, was transferred to hemodialysis, or died). RESULTS: Survival analyses were performed using Kaplan-Meier survival curves and Cox proportional hazards. Total follow-up was 34 months. The mean age was 59 years (54% female). The weight category percentages were as follows: underweight: 8%; normal: 51%; overweight: 29%; and obese 12%. The multivariate model showed a higher risk of death for a body mass index 30 kg/m². Patients were divided into five categories according to quintiles of body weight changes during the first year of dialysis: +7.1%. Patients in the lowest quintile had significantly higher mortality, whereas no negative impact was observed in the other quintiles. CONCLUSION: These findings suggest that overweight/obesity and a positive body weight variation during the first year of peritoneal dialysis therapy do not increase mortality in incident dialysis patients in Brazil.