Proteinuria and decreased body mass index as a significant risk factor in developing end-stage renal disease

Body mass index (BMI) is a significant predictor of developing end-stage renal disease (ESRD). The relation between a change in BMI (DeltaBMI) and the incidence of ESRD has not been examined in any large epidemiologic studies.

We determined the DeltaBMI in subjects who participated in the Okinawa General Health Maintenance Association (OGHMA) screenings in 1983 and again in 1993. Screenees were free of ESRD at the 1993 screening and were then monitored until the end of 2000 to determine whether they developed ESRD. Participants were identified using ID numbers, birthdates, and other identifiers. Details of every ESRD patient treated in Okinawa are maintained in an independent community-based dialysis registry. Multivariate logistic analyses were performed to determine the significance of a DeltaBMI on the incidence of ESRD using SAS. The ethics committee of the OGHMA approved the study protocol. Only coded data were used for this study.

Among the 92,364 subjects aged 30-89 years screened in 1983, 29,011 (31.4%) returned for the 1993 screening. The median DeltaBMI was 2.1%, and the subjects were divided into two groups: DeltaBMI < 2.1% (G1) and DeltaBMI > or = 2.1% (G2). The cumulative incidence of ESRD was 0.31% in G1 (ESRD in 44) and 0.14% in G2 (ESRD in 21). The odds ratio (95% confidence interval) of developing ESRD based on a DeltaBMI was 2.268 (1.284-4.000, P < 0.01) after adjusting for age, sex, systolic blood pressure, BMI in 1983, and proteinuria.

The findings of the present study suggest that a DeltaBMI is an independent risk factor for the incidence of ESRD, especially for those with proteinuria. The reasons for the BMI change were not recorded in this study. Unintentional weight loss, however, might warrant evaluation for the presence or progression of chronic kidney disease.