Cut-off of body mass index and waist circumference to predict hypertension in Indian adults.

Aim: To determine the cut-off values of body mass index (BMI) and waist circumference to predict hypertension in adults in north India.

Methods: A community based cross-sectional study was conducted in 801 subjects in Kanpur, aged 20 years and above, using multistage stratified random sampling technique. A pre-tested structured questionnaire was used to elicit the required information from the study participants and the diagnostic criteria for hypertension were taken according to the Seventh Joint National Committee Report on Hypertension (JNC-7). Receiver operating characteristic (ROC) analysis was used to estimate the cut-off values of BMI and waist circumference to predict hypertension.

Results: The ROC analysis revealed that BMI is a good predictor of hypertension for both men (area under the ROC curve 0.714) and women (area under the ROC curve 0.821). The cut-off values of BMI for predicting hypertension were identified as ≥ 24.5 kg/m(2) in men and ≥ 24.9 kg/m(2) in women. Similarly, the ROC analysis for waist circumference showed that it is a good predictor of hypertension both for men (area under the ROC curve 0.784) and women (area under the ROC curve 0.815). The cut-offs for waist circumference for predicting hypertension were estimated as ≥ 83 cm for men and ≥ 78 cm for women. Adults with high BMI or high waist circumference had a higher prevalence of hypertension, respectively.

Conclusion: Simple anthropometric measurements such as BMI and waist circumference can be used for screening people at increased risk of hypertension in order to refer them for more careful and early diagnostic evaluation. Policies and programs are required for primary and secondary prevention of hypertension.