Abstract: Objective To investigate the relationship between body mass index (BMI) and technical survival in peritoneal dialysis (PD) patients. Methods A total of 348 PD patients (aged 48.2±15.5 years, 62% males) treated in Peking University Shenzhen Hospital from 2000 to 2014 were enrolled in this retrospective and cohort study. BMI was calculated using the first recorded body height and weight within 2~6 months after the initiation of PD. Patients were grouped according to the recommendation by World Health Organization for Asians. All patients were followed up until death, transferring to hemodialysis, kidney transplantation, loss
of follow-up, or Oct. 31, 2014. The main endpoint included technical failure (death or permanently transferred to hemodialysis), and the secondary endpoint consisted of all-cause mortality, cardiovascular and cerebrovascular mortality, coronary heart disease event, stroke, and the first episode of peritonitis. Cox regression was used for data analysis. Results After the adjustment of age, sex, education, primary disease and heart failure, the hazard ratio (HR) for technical failure was 3.590 (95% CI 1.526~8.447, P=0.003) in low BMI group and was 0.932 (95% CI 0.493~1.762, P=0.829) in high BMI group, as compared with that in normal BMI. Allcause mortality, and cardiovascular and cerebrovascular mortality were higher in low BMI group than in normal BMI group (in low BMI group, total mortality HR=5.462, 95% CI 1.743~17.110, P=0.004; cardiovascular and cerebrovascular mortality HR=9.403, 95% CI 2.409~36.700; P=0.001), but were similar between high BMI group and normal BMI group (P＞0.05). No statistical significance was found in the relationship between BMI and the secondary endpoint including coronary heart disease event, stroke, and the episode of peritonitis (P＞0.05). Subgroup analyses revealed that the relationship between BMI and technical failure was not affected by age, sex, education, primary disease and cardiovascular diseases (interacted P＞0.05). Conclusions In PD patients, low BMI was independently associated with technical failure, all-cause mortality, and cardiovascular and cerebrovascular mortality, but not with coronary heart disease event, stroke and the episode of peritonitis. However, high BMI was unrelated to the events of main endpoint and secondary endpoint.

Key words: Peritoneal dialysis, body mass index, technical survival, retrospective cohort study, Cox regression