Low birth weight and end-stage renal disease: demographic analysis by region in Japan

Background We have previously shown regional differences in the incidence of end-stage renal disease (ESRD) within Japan, which is ethnically homogenous, suggesting that non-genetic factors may contribute to the differences. We examined regional distribution in the incidence of low birth weight (LBW), a surrogate for low nephron number, in our search for an explanation. Methods Each year, the Ministry of Health, Labour and Welfare of Japan and the Japanese Society for Dialysis Therapy report the number of LBW babies and patients initiating maintenance dialysis in each prefecture of Japan, respectively. In this study, we calculated the annual incidences of LBW and ESRD in 11 regions of Japan over a 24-year period from 1984 to 2007. Results There were distinct regional differences in the annual incidences of both LBW and ESRD ( p