['The association between body mass index (BMI) and cardiovascular risk factors, widely recognized in Western populations, was evaluated on subjects living in a rural Japanese area.', 'A cross-sectional survey.', 'A total of 16 871 subjects aged 40-59 y, from a rural area in Japan, participated in an annual health examination. All of the subjects were required to answer six items in a questionnaire on health behavior and provide blood samples.', "Quetelet's index, blood pressure, total cholesterol, high-density lipoprotein cholesterol, health practices on exercise, drinking and smoking.", 'The mean BMI in the population was 23.1+/-2.9. After adjustment for sex, age and six health habits, the BMI was found to be significantly associated with blood pressure and the serum lipid levels by multivariate logistic regression analysis. The adjusted odds ratio for hypertension (> or =140/90 mmHg) against the lowest quartiles of BMI (separated by 20, 25 and 28) were 1.6, 2.8 and 5.2, respectively. The adjusted odds ratio for hypercholesterolemia (> or =240 mg/dl) against the lowest quartiles of BMI were 2.1, 3.3 and 4.6, respectively.'] Is body mass index a good predictor of hypertension and hyperlipidemia in a rural Japanese population?