Calculus disease of upper urinary tract in San Francisco Chinese.

Acute calculus disease of the upper urinary tract was studied retrospectively (1974-1978) in San Francisco Chinese and Caucasians. The Chinese population of San Francisco represents approximately 10 per cent of the total population. Yet the incidence of upper tract calculus among Chinese was found to be about twice that among Caucasians (as judged by admission at three major hospitals, one of them with Chinese patients only). The stones which develop in Chinese people are predominantly of mixed calcium and uric acid (45 per cent) and pure uric acid (15 per cent). This finding suggests that the origin of recurrent calculus disease is related to high intake of purines inherent in the Chinese diet, inducing hyperuricosuria.