Necessity of Both Waist Circumference and Waist-to-Height Ratio for Better Evaluation of Central Obesity

Background: Waist-to-height ratio (WHtR) has been shown to be a better discriminator of cardiovascular risk than waist circumference (WC). The purpose of this study was to determine whether cardiometabolic risk is increased in men showing large WC but not showing high WHtR. Methods: Subjects (26,017 middle-aged men) were divided into four groups of normal WC (<85 cm) and normal WHtR (<0.5), large WC (>= 85 cm) but normal WHtR, normal WC but high WHtR (>= 0.5), and large WC and high WHtR. Odds ratios (ORs) of each group versus the group with normal WC and normal WHtR for each cardiometabolic risk factor were calculated after adjustment for age, alcohol drinking, smoking, and regular exercise. Results: Subjects showing large WC but normal WHtR and subjects showing normal WC but high WHtR were 6.1% and 4.5%, respectively, of all subjects. ORs of subjects with large WC but normal WHtR versus subjects with normal WC and normal WHtR for hyperglycemia [1.80 (95% confidence interval, CI, 1.55-2.09)], dyslipidemia [2.28 (95% CI 2.05-2.54)], high blood pressure [1.86 (95% CI 1.67-2.07)], and a cluster of these three risk factors [3.10 (95% CI 2.46-3.92)] were significantly higher than a reference level of 1.00 (p < 0.01) and were comparable with the ORs of subjects with normal WC but high WHtR. Conclusion: Cardiometabolic risk was significantly increased in subjects with large WC and normal WHtR, and thus it is recommended to use both WC and WHtR for a more correct diagnosis of central obesity.