Determination of the Best Anthropometric Index of Obesity for Prediction of Prehypertension and Hypertension in a Large Population - Based Study: The Azar - Cohort

Abstract

Background: Identification of reliable predictors of hypertension and prehypertension in each population is essential for early detection of at-risk people and also planning preventive strategies. Objectives: The present study aimed to assess the abilities of different indices of general and central obesity in the prediction of incident prehypertension and hypertension in a large population-based study in Iran. Methods: In this cross-sectional study, we evaluated the anthropometric and blood pressure measurements in 10,137 subjects (35 - 70 years) from Azar- Cohort study, north-west of Iran. Blood pressure was measured twice, with 10 minutes apart, from both upper extremities. Height, weight, waist, and hip circumferences measured according to the NIH guidelines. Hypertension considered as systolic blood pressure >= 140 and diastolic blood pressure >= 90 mmHg or current use of antihypertensive medication for management of hypertension. Results: The mean BMI (kg/m(2)), WC (cm), waist-to- hip ratio (WHR), and waist- to- height ratio (WHtR) were 28.75 +/- 4.83,94.69 +/- 11.23, 0.90 +/- 0.07, and 0.58 +/- 0.07, respectively. The prevalence of prehypertension and hypertension were 16.3% and 23.3%, respectively. There was a significant association between prehypertension and hypertension with all included anthropometric indices in both men and women (All P < 0.001). In men, obesity increased the risk of prehypertension and hypertension by 3.13 (95% CI: 2.48 - 3.94) and 4.06 (95% CI: 3.23 - 5.10), respectively. In women with WHtR > 0.5 cm, the risk of hypertension increased by 6.27 (95% CI: 4.39 - 8.95) times. Conclusions: According to the result of this large population-based study, BMI is the best predictor of prehypertension and hypertension in men and also the waist- to- hip ratio combined with BMI were the best predictors of prehypertension and hypertension in women. These findings may have significant implications in using the most useful screening index for predicting hypertension in Iranian adults and also using waist- to- hip ratio for early detection of pre-hypertension.