Anthropometrics and Metabolic Syndrome in Healthy Korean Adults: A 7-Year Longitudinal Study

Background and Objective Of anthropometric measurements, body-mass index (BMI) and waist circumference (WC) have been used as determinants of obesity. The waist-to-height (WtHR) is simple, easy to calculate, and easy to apply to various age groups, but its wide use is limited because of a lack of studies. This 7-year longitudinal study was performed to identify the usefulness of WtHR compared with BMI and WC for predicting metabolic syndrome (MetS). Material and Methods Of 22,379 people who visited a health screening center over the course of one year, 5,802 men and 3,303 women who consented to the study and had no MetS were followed for 7 years to evaluate the development of MetS. The National Cholesterol Education Program Adult Treatment Panel III criteria were adapted to diagnose MetS. Height, weight, and WC were measured, and traditional reference values for BMI (23 kg/m2), WC (men 90 cm, women 80 cm), and WtHR (0.5) were calculated; in addition, other cut-off values were calculated by analyzing receiver operating characteristic (ROC) curves. The relative risk (RR) of developing MetS was calculated by Cox proportional-hazards regression using the cut-off values from traditional obesity references and ROC analysis. Results Ultimately, 1,724 (29.7%) men and 627(19.0%) women were diagnosed with MetS. Among men with BMI <23 and >23, 15.1% and 37.0% developed MetS, respectively, resulting in an RR of 0.393 (95% confidence interval [CI] 0.349-0.443, p <0.001). Among men with WC <90 cm and >90 cm, 25.5% and 51.4% developed MetS, respectively, resulting in an RR of 0.442 (95% CI 0.389–0.502, p <0.001). WtHR had the lowest RR at 0.388 (95% CI 0.350–0.430, p <0.001). Among women with BMI<23 and >23, 10.2% and 35.5% developed MetS, respectively, resulting in an RR of 0.290 (95% CI 0.249–0.319, p <0.001). Among women with WC <80 cm and >80 cm, 13.6% and 39.2% developed MetS, respectively, resulting in an RR of 0.346 (95% CI 0.295–0.407, p <0.001). Among women with WtHR <0.5 and > 0.5, 12.7% and 38.2% developed MetS, respectively, resulting in an RR of 0.341 (95% CI 0.290–0.401, p <0.001). Conclusion The results of this study on middle-aged men and women show that a WtHR of 0.5, along with BMI and WC, has diagnostic value in predicting MetS. More studies with people of various ethnicities and ages should be conducted, and WtHR should be recognized as a potential health-management tool.