Epidemiological studies on renal papillary necrosis with diabetes mellitus in Japan

Eighty-six cases of renal papillary necrosis (RPN) published in Japan over the years 1949-1980 were studied. While several hundreds cases of RPN were reported in certain European countries and the USA, only 5 cases were published in Japan up until 1960. However, the number of case reports has increased to 28 over the 5 year period of 1976-1980. The ratio of diabetics (62 cases) to nondiabetics (24 cases) is about 2.6:1 and is the same as that reported by Lauer in the USA. In diabetics, RPN was more frequently seen in females (3.4:1) and at more advanced age. Frequency of bilateral occurrence was high (47.5%). The prevalence of the association of glomerulosclerosis (75.0%) was higher than that reported by Silverman et al. in the USA (47.1%). The Incidence of the association of disturbances of consciousness (29.5%) was similar to that reported by Edmondson et al.. It was concluded that the number of cases of RPN with diabetes mellitus in Japan started to increase about 20 years later than in the USA, and that the frequency of the association between RPN and diabetic glomerulosclerosis in Japan seems to be higher than in the USA. Furthermore, it was noted that RPN was frequently associated with hyperosmolar nonketotic diabetic coma.