Genetic and environmental effects and characteristics of Japanese end-stage renal disease patients.

Few studies of end-stage renal disease (ESRD) investigate genetic and environmental effects simultaneously in one racial/ethnic group. United States Renal Data System data show racial differences in primary causes of ESRD, survival rates, and causes of death. Comparing these with Japanese Society for Dialysis Therapy data, survival rates appear better for Japanese than for US patients. To explore genetic and environmental differences, we investigated incident and prevalent ESRD patient characteristics. The United States Renal Data System and Japanese Society for Dialysis Therapy databases were analyzed between 1983 and 2002 for the following patient subsets: Americans excluding Asian Americans (n=1,153,974); Asian Americans excluding Japanese Americans (n=35,983); Hawaiian and non-Hawaiian Japanese Americans by state, race, and Japanese surname (n=3932); native Japanese living in Japan (n=450,593). Japanese Americans tended to be older, male, have more diabetes and hypertension and less glomerulonephritis, and to die more often of heart failure than the other US groups. Adjusted mortality hazard ratios were 0.70 for non-Japanese Asian Americans and 0.75 for Japanese Americans vs. non-Asian Americans (1.00). Hawaiian Japanese patients tended to be older, with more diabetes and hypertension and less glomerulonephritis than the other Japanese groups; their survival rates improved after adjustment for rate of diabetes. Japanese American ESRD patients differ from Asian and non-Asian Americans, and from native Japanese, despite similar genetic make-ups. Both genetic and environmental factors may affect patient outcomes.