Body mass index and the risk of development of end-stage renal disease in a screened cohort

Background. Obesity is associated with proteinuria and could be a risk factor for end-stage renal disease (ESRD). However, few studies have examined the significance of body mass index (BMI) as a risk factor for the development of ESRD in the general population. Methods. We examined the relationship between BMI and the development of ESRD using data from a 1983 community-based screening in Okinawa, Japan. Screenees who developed ESRD by the end of 2000 were identified through the Okinawa Dialysis Study registry. BMI data were available for 100.753 screenees (47,504 men and 53,249 women) aged greater than or equal to20 years. The cumulative incidence of ESRD was analyzed according to the quartile of BMI: <21.0 21.0 to 23.1, 23.2 to 25.4, and >= 25.5 kg/m(2). Results. The mean (SD) BMI of the screenees was 23.4 (3.3) kg/m(2) (range 7.9 to 59.1 kg/m(2)); the mean was 23.4 kg/m(2) for both men and women. During the follow-up period, 404 screenees (232 men and 172 women) developed ESRD. The cumulative incidences of ESRD per 1000 screenees were, from the lowest to highest BMI quartile, 2.48, 3.79, 3.86, and 5.81. The odds ratio (95% CI) of BMI for developing ESRD, after adjustment for age, sex, systolic blood pressure, and proteinuria, was 1.273 (1.121-1.446, P = 0.0002) for men and 0.950 (0.825-1.094, not significant) for women. Conclusion. We found that BMI was associated with an increased risk of the development of ESRD in men in the general population in Okinawa. The maintenance of optimal body weight may reduce the risk of ESRD.