Background and purpose: Body mass index is most commonly used as the obesity index. Recently, waist circumference (WC) has been shown to be associated with the risk of cardiovascular disease (CVD). However, no studies have observed an association between WC and CVD in Japan. We examined the relationships of WC and body mass index with CVD in a Japanese urban population.
Methods: We studied 5474 Japanese individuals (aged 30 to 79 years without CVD at baseline) who completed a baseline survey and received follow-up through December 2005. WC was measured at the umbilical level of participants in the standing position to the nearest 1 cm. The Cox proportional hazard ratios for CVD according to the quartiles of WC were calculated after adjustment for age, smoking, and drinking status.
Results: During a mean follow-up of 11.7 years, 207 strokes and 133 myocardial infarctions were documented. In women, compared with the lowest quartile (WC <70 cm), the hazard ratio (95% CIs) after adjusting for age, smoking, and drinking in the highest quartile (WC >or=84 cm) were 1.85 (1.03 to 3.31) for CVD and 2.64 (1.16 to 6.03) for stroke. However, no such relationships of WC with CVD or stroke risk were observed in men. After further adjustment of hypertension, diabetes, and hypercholesterolemia, all of the mentioned relationships were not statistically significant. No associations of body mass index with CVD or strokes were observed.
Conclusions: WC may be a better predictor for CVD or stroke in Japanese women.