[A follow-up study on dietary factors of kidney stones in Bao'an district, Shenzhen City].

OBJECTIVE

To evaluate the major dietary factors of kidney stones in Bao'an District of Shenzhen City and provide a scientific base for further effective prevention of kidney stones.

METHODS

Following the process of stratified cluster random sampling in Bao'an district, a cross-sectional study (July-Aug, 2000) was conducted for collecting the base-line data on kidney stones from a population of permanent residents who were over 15 years old, exclusive of those who had had kidney stones or could not correctly respond to the questionnaire review. Then, a follow-up survey (July-Sept, 2002) for incident kidney stone cases was carried out among those residents. The methods for measurement included questionnaire and face-to-face interview, clinical examination and abdominal ultrasonography. All the investigators and interviewers were trained for the field work. And the data processing, dataset and analyses were performed using Visual-Fox 6.0 and SAS 6.12. The risk factors of kidney stoned were comprehensively analyzed for dietary, life style, and family history of stones. The statistical analyses included case-control comparison, factor analysis, correlation analysis, cluster analysis and logistic regression.

RESULTS

There were 305 kidney stones patients among 4552 follow-up members, the cumulative incidence of 2 years was 6.92%. The kidney stones were associated with the factors: menopause, RR=2.433; family history of stones, RR=1.544; sea foods, the RR (5-7 times/week vs < or = 1-2 times/month) was 9.032; fruits, the RR (< or = 1-2 times/month vs > or = 1-2 times/week) was 2. 249; sweet foods, the RR (5-7 times/week vs 1-2 times/week) was 2. 568; bean and bean products, the RR (5-7 times/week and < or = 1-2 times/month vs 1-2 times/week) was 2.184 and 1.689.

CONCLUSION

Changing the inappropriate habitual eating patterns and generalizing the use of proportioning dietary should be the main measures to prevent kidney stones.