Waist wins

Adiposity, commonly measured using body mass index (BMI) and waist circumference (WC), is now being assessed with newer anthropometric indices that have emerged to capture variations in body shape and height. How these indices compare in terms of discriminating prevalent elevated blood pressure (BP) and hypertension in Middle Eastern populations is unclear. This study aimed to compare the associations of WC, body roundness index (BRI), a body shape index, weight-adjusted waist index (WWI), and BMI with systolic and diastolic blood pressure (DBP) and assess how well these measures discriminate prevalent elevated BP (systolic blood pressure [SBP] 120–129 mm Hg with DBP < 80 mm Hg) and hypertension (SBP ≥ 130 or DBP ≥ 80 mm Hg). In this cross-sectional study of Saudi adults (n = 1041), anthropometric data were measured; BP was measured 3 times using standardized procedures. We ran adjusted-linear (difference in SBP/DBP per 1 standard deviation [SD] higher index) and logistic regression (odds per 1 SD). Discrimination was evaluated using receiver operating characteristic and area under the curve; optimal cutoffs were selected using Youden’s index, and sensitivity/specificity with 95% confidence intervals were obtained. In fully adjusted linear models, a 1 SD higher WC (≈17 cm) was associated with higher SBP and DBP (+4.80/+3.68 mm Hg; both P < .0001), with smaller differences for BMI and BRI. In fully adjusted logistic models, WC was significantly associated with elevated BP and hypertension in the pooled sample and in women, whereas elevated BP associations were not significant in men. Receiver operating characteristic analyses also showed WC had the highest discrimination for elevated BP and for hypertension. Sex-specific optimal cutoffs were identified. In Saudi adults, WC outperformed BMI, BRI, WWI, and a body shape index for discriminating prevalent elevated BP and hypertension, particularly in women. These findings support prioritizing WC in screening to identify adults more likely to have prevalent elevated BP or hypertension. Identified sex-specific cutoffs can inform clinical practice. Future prospective studies should validate these cutoffs before implementation.