Evaluation of waist size as a health risk indicator for obesity.

Abstract

The purpose of this study is to evaluate waist size as an indicator of health risk among subjects considered to have normal body construction based on height-weight obesity indices. For estimating standard waist sizes based on height, a regression equation was formulated from 46 male subjects who had no abnormal findings in their health checkups. The regression equation was as follows: Standard waist size (cm) = 0.8 X height (cm)-57.7. The ratio of measured waist size to standard waist size was defined as the "waist ratio". The correlation coefficient between the waist ratio and the modified Broca's obesity index was 0.898 (N = 207, p less than 0.01). To clarify the meaning of the waist ratio, 95 male subjects were divided into three groups on the basis of the difference between their waist ratio and their obesity index. The group whose waist ratios were larger than their obesity indices had significantly worse findings than the group whose waist ratios were not in the following medical categories: systolic blood pressure, glutamic oxaloacetic transaminase levels, gamma glutamyl transpeptidase levels, uric acid levels, total bilirubin, electrocardiogram readings and optic funduscopic observation. Accordingly, the waist ratio derived from waist size might be useful for assessing obesity-related health risks even for subjects judged to be normal from the height-weight obesity index.