Body mass index and mortality risk in Asian peritoneal dialysis patients in Hong Kong-impact of diabetes and cardiovascular disease status.
BACKGROUND
Obesity increases mortality in the general population, but improves survival in hemodialysis patients. In peritoneal dialysis (PD) patients, the reported effect is controversial. We investigated the effect of body mass index (BMI) on patient survival in Asian PD patients.


METHODS
The survival of incident Asian PD patients from 2001 to 2008 in a single center in Hong Kong was analyzed retrospectively. Baseline demographic and clinical data were collected from patient records. Patients who had a total Kt/V below 1.7 or who died within 6 months were excluded. The BMI was categorized using the World Health Organization recommendation for Asian populations.


RESULTS
In the 274 study patients [154 men (56%); 138 with diabetes (50.4%); mean age: 63.4 ± 14.6 years; mean BMI: 21.97 ± 3.23 kg/m(2); 37 underweight (13.5%); 35 obese (12.8%)], the relative risk (RR) for mortality [adjusted for age, diabetes status, and cardiovascular disease (CVD)] was similar for the normal and overweight groups, but higher for the underweight (RR: 1.909; p = 0.028) and obese groups (RR: 1.799; p = 0.048). The increased mortality in obese patients was more prominent in patients with diabetes (RR: 1.9 vs 1.19 in patients without diabetes; p = 0.074 and 0.76 respectively), and in patients with CVD (RR: 8.895 vs 1.642 in patients without CVD; p = 0.012 and 0.122 respectively).


CONCLUSIONS
In Asian PD patients, the relationship between BMI and mortality was U-shaped, with higher mortality in the underweight and obese patients. The negative impact of obesity was more prominent in patients with diabetes and CVD.
Care Hospitals, Hyderabad, Andhra Pradesh, India; Huashan Hospital, Fudan University, Shanghai, PR China; and Dr. Lee Iu Cheung Memorial Renal Centre, Department of Medicine, Tung Wah Hospital, Hong Kong SAR, PR China.
Verukonda Ravi
VR
Kiran
Care Hospitals, Hyderabad, Andhra Pradesh, India; Huashan Hospital, Fudan University, Shanghai, PR China; and Dr. Lee Iu Cheung Memorial Renal Centre, Department of Medicine, Tung Wah Hospital, Hong Kong SAR, PR China.
Tong Ying
TY
Zhu
Care Hospitals, Hyderabad, Andhra Pradesh, India; Huashan Hospital, Fudan University, Shanghai, PR China; and Dr. Lee Iu Cheung Memorial Renal Centre, Department of Medicine, Tung Wah Hospital, Hong Kong SAR, PR China.
Terence
T
Yip
Care Hospitals, Hyderabad, Andhra Pradesh, India; Huashan Hospital, Fudan University, Shanghai, PR China; and Dr. Lee Iu Cheung Memorial Renal Centre, Department of Medicine, Tung Wah Hospital, Hong Kong SAR, PR China.
Sing Leung
SL
Lui
Care Hospitals, Hyderabad, Andhra Pradesh, India; Huashan Hospital, Fudan University, Shanghai, PR China; and Dr. Lee Iu Cheung Memorial Renal Centre, Department of Medicine, Tung Wah Hospital, Hong Kong SAR, PR China.
Wai Kei
WK
Lo
D000368:Aged; D044466:Asian People; D015992:Body Mass Index; D002318:Cardiovascular Diseases / Q000401:mortality*; D003920:Diabetes Mellitus / Q000401:mortality*; D005260:Female; D006723:Hong Kong; D006801:Humans; D007676:Kidney Failure, Chronic / Q000401:mortality / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000401:mortality*; D010530:Peritoneal Dialysis / Q000401:mortality*; D012189:Retrospective Studies; D012307:Risk Factors; D016019:Survival Analysis
Body mass index; cardiovascular disease; diabetes; mortality