Blood pressure in relation to traditional and emerging anthropometric indices: a cross-sectional study of older...

Due to the increasing trend of hypertension (HTN) prevalence and consequences, investigations in related risk factors including age and obesity has always been of great interest. This study aimed to investigate the association between certain anthropometric indices with HTN in a sample of Iranian older adults.

This cross-sectional study used the data from the first wave of Birjand Longitudinal Aging Study (BLAS) (n = 1364). Body mass index (BMI) and waist circumference (WC) were assessed as old anthropometric indices, and body roundness index (BRI) and a body shape index (ABSI) were assessed as new body composition indices. Analyses were conducted using binary logistic regression and receiver-operating characteristic curves analysis (ROC curve).

Among 1,364 participants, 657 (48.2%) were men, with a mean age of 69.77 ± 7.66 years. ROC curve demonstrated poor discriminatory ability for all anthropometric indices, with AUC values ranging from 0.48 to 0.65 across outcomes and sex-stratified analyses. In adjusted regression models, BMI and WC were statistically associated with HTN and elevated blood pressure measures; however, effect sizes were small (ORs ≈ 1.04-1.11 per unit increase). In contrast, ABSI and BRI showed no consistent associations with HTN outcomes. Regression models demonstrated very low explanatory power (pseudo-R² ≤ 0.01), indicating that anthropometric indices explained only a minimal proportion of HTN variability.

In this cohort of older adults, neither traditional nor emerging anthropometric indices demonstrated meaningful discriminatory or predictive ability for HTN. Although BMI and WC showed statistically significant associations with blood pressure outcomes, the observed effect sizes and explanatory power were small. These findings suggest that anthropometric measures alone have limited utility for HTN risk stratification in older populations, and that newer indices such as ABSI and BRI do not provide meaningful improvement over conventional measures.