Waist circumference, body mass index and waist-height ratio: Are two indices better than one for identifying hypertension risk in older adults?

Abstract

Objective: To investigate if the combination of Waist Circumference (WC) and Body Mass Index (BMI) or Waist to Height Ratio (WHtR) and BMI measures is superior to the separate indicators in identifying hypertension risk in older adults from southern Brazil.

Method: This cross-sectional study analyzed data from the second wave (2013/14) of a population- and household-based survey carried out with 1197 older adults (778 women). Hypertension (i.e., outcome) was identified by self-report. The independent variables were body mass index (BMI≥27kg/m²), waist circumference (WC≥88cm for women and WC≥102cm for men), waist/height ratio (WHtR≥0.5), and the combined indexes BMI+WC (BMI≥27kg/m²+WC≥88cm for women and WC≥102cm for men) and BMI+WHtR (BMI≥27kg/m²+WHtR≥0.5). The associations were explored using binary logistic regression.

Results: The results showed sex differences in all study characteristics. In women, all indicators were associated with the outcome, after adjustments (age, race/color, marital status, schooling, smoking, alcohol consumption, physical activity, and diabetes). WHtR was the indicator most strongly associated with hypertension (OR=2.97; 95% CI 1.58 to 5.59). For men, only BMI and the combined indicators were associated with hypertension. Combined measures of BMI+WHtR showed a stronger association with the outcome (OR=2.68; IC95% 1.62 to 4.44).

Conclusion: The associated indicators differed between the sexes. The combination of BMI+WC and BMI+WHtR using current cut-off points may provide an improved measure of hypertension risk.

Keywords: Aging; Anthropometry; High blood pressure; Nutritional status; Overweight.