Waist/height ratio: an effective index for abdominal obesity predicting diabetes and hypertension

Objective To evaluate the feasibility and value of waist-height ratio (WHtR) as an abdominal obesity index in predicting the risk of diabetes and hypertension. Methods Data came from the 1998 Guangdong provincial diabetes survey, a population-based cross-sectional study, and 11742 residents aged 20-74 years (male 5450, female 6292, age 43.8±13.6 years) were enrolled. Partial correlation analysis of WHtR, waist cincumference (WC), body mass index (BMI), waist/hip ratio (WHR) and postprandial blood glucose (2hPG), systolic and diastolic blood pressure, ROC curve analysis in diabetes and hypertension, and multivariate logistic regression analysis were conducted. Results In presented population, the distribution characteristics of WHtR and BMI were identical in both gender population, not WC and WHR. After adjusted age and sex, WHtR showed positive correlation with WC (r=0.94, P0.0001) significantly, the correlation between WC and body height was significantly higher than WHtR (r=0.25 vs r=-0.08). The relationship between SBP, DBP, 2hPG and WHtR were similar to WC. Of the four anthropometric indices, WHtR was found to have the largest areas under the ROC curve relative to diabetes(0.751,95%CI 0.727-0.775)and hypertension (0.716,95%CI 0.703-0.729). The best cut-off point of WHtR was 0.5 in diabetes and in hypertension(0.49 in male, 0.50 in female), WC was 78 cm in hypertension( 80 cm in male, 76 cm in female),80 cm in diabetes(82 cm in male, 78 cm in female), WHR was 0.86 in hypertension( 0.87 in male, 0.84 in female), 0.87 in diabetes (0.88 in male,0.85 in female), BMI was 23 in both diseases and gender. The sensitivity and specificity for identification of diabetes and hypertension of WHtR at 0.5 were better than WC and WHR, especially in BMI25 population. Multivariate logistic regression analysis showed that, after controlling age, history, physical activity, sex, BMI, WHR and WC, the diabetes andhypertensionriskoddsratio(OR)ofWHtR≥0.5 were 1.90(1.38-2.63) and 2.13(1.77-2.56). WHtR and BMI were the most important predictive factors of diabetes and hypertension risk among the four anthropometric indexes. Conclusion WHtR is simple and no significantly difference between male and female, it correlates with WC significantly and keeps its characteristics, and is less affected by body height. WHtR≥0.5 may effectively predict the risk of diabetes and hypertension, its predicting power is closer to or better than WC and WHR. This result suggests that WHtR may be a simple and effective index of abdominal obesity.