Relationship of body size and initial dialysis modality on subsequent transplantation, mortality and weight gain of ESRD patients.

Background: Whether peritoneal dialysis (PD) treatment leads to greater weight gain than with hemodialysis (HD) and if this limits access of obese end-stage renal disease patients to renal transplantation has not been examined. We undertook this study to determine the interrelationship between body size and initial dialysis modality on transplantation, mortality and weight gain.

Methods: Time to transplantation, time to death and weight gain were estimated in a 1:1 propensity score-matched cohort of incident HD and PD patients treated in facilities owned by DaVita Inc. between 1 July 2001 through 30 June 2006 followed through 30 June 2007 (4008 pairs) in four strata of body mass index (BMI) (<18.5, 18.5-24.99, 25.00-29.99 and ≥ 30 kg/m(2)).

Results: Transplantation was significantly more likely in PD patients [adjusted hazards ratio (aHR) 1.48, 95% confidence interval (95% CI) 1.29-1.70]; the probability of receiving a kidney transplant was significantly higher in each strata of BMI >18.5 kg/m(2), including with BMI ≥ 30 kg/m(2) (aHR 1.45, 95% CI 1.11-1.89). PD patients had significantly lower all-cause mortality for patients with BMI 18.50-29.99 kg/m(2). Both these findings were confirmed on analyses of the entire unmatched incident cohort (PD 4008; HD 58 471). The effect of dialysis modality on weight gain was tested in 687 propensity score-matched pairs; the odds of >2, >5 or >10% weight gain were significantly lower in PD patients.

Conclusion: Treatment with PD is less likely to be associated with a significant weight gain and does not limit the access of obese patients to renal transplantation.