Large body mass index does not predict short-term survival in peritoneal dialysis patients.

OBJECTIVE: Higher than normal body mass index (BMI) is associated with an increased risk of death in the general population. We examined the effect of higher than normal BMI on patient and technique survival in peritoneal dialysis patients (PD), controlling for comorbidity, initial albumin, dialysate-to-plasma ratio of creatinine (D/P(Cr)), and initial urea clearance (Kt/V).

DESIGN: Registry database.

SETTINGS: Four dialysis centers.

PATIENTS: Incident PD patients.

METHODS: All data were collected prospectively. Demographics, BMI, serum albumin, D/P(Cr), and comorbidity using the Charlson Comorbidity Index (CCI) were determined at the start of PD. 104 patients with a high BMI (> 27) were matched to a control group of 104 patients with normal BMI (20-27) for age, gender, presence of diabetes, and CCI. Patient and technique survival were compared using Cox proportional hazards model.

MAIN OUTCOME MEASURES: Patient and technique survival.

RESULTS: The groups were of similar age (56.1 vs 56.7 years), sex (60% males in both groups), race (Caucasian 80% vs 86%), presence of diabetes (40% vs 37%), CCI score (5.4 in both groups), initial albumin (3.6 vs 3.5 g/dL), and D/P(Cr) (0.65 in both groups). Kaplan-Meier survival analysis showed similar 2-year patient survival between large BMI (> 27) and control (20-27) groups (76.6% vs 76.1%). Two-year technique survival was also similar between the two groups (59.7% vs 66.8%). With Cox proportional hazards analysis, BMI was not a predictor of patient mortality or technique survival when controlling for initial albumin, D/P(Cr), and initial Kt/V.

CONCLUSIONS: We conclude that a BMI above normal is not associated with any increased or decreased risk of death in patients on PD for 2 years.