Optimum cutoff values of anthropometric indices of obesity for predicting hypertension: more than one decades of follow-up in an Iranian population.

Abstract

We determined cutoff points of body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR), and waist-to-height ratio (WHtR), for predicting hypertension in an Iranian population. Study sample included 6359 (3678 female) participants aged ≥20 and <60 years of a prospective cohort. The sex stratified multivariate hazard ratios (HRs) for all indices were estimated using Cox regression in two age groups (20-39 and 40-59 years). Receiver operating characteristic (ROC) was used to evaluate the predictive ability and determine the optimal cut-off values of the indices. In both genders and two age groups, the confounders adjusted HRs were significant for general and central obesity measures indices. AUCs of the indices were similar in men; however, among women 40-59 years, WC and WHtR had significantly higher AUC compared to BMI. Generally, the optimal cut-off values were higher in the 40-59 year age group. Optimal BMI, WC and WHR and WHtR cut-off values were 24.15 kg/m2, 90.5 cm, 0.90 and 0.49 among men, aged 20-39 years; the corresponding values were 28.41 kg/m2, 86.5 cm, 0.96 and 0.50 in men aged 40-59 years, respectively. In women, the aforementioned values were 26.38 kg/m2, 83.5 cm, 0.79 and 0.51 in the age group of 20-39 years, and 29.57 kg/m2, 90.5 cm, 0.88 and 0.59 in the 40-59 year age group, respectively. Our results suggest that gender and age differences in the association between anthropometric indices and hypertension should be considered.