Trunk-to-Appendicular Fat Ratio and Blood Pressure: Survey-Weighted Regression, Spline Modeling, and Exploratory...

Central adiposity is closely linked to blood pressure (BP), yet body mass index (BMI) and waist circumference (WC) may not fully capture fat distribution. We analyzed 4307 adults from NHANES 2011-2018 with whole-body dual-energy X-ray absorptiometry (DXA) to examine whether the trunk-to-appendicular fat ratio (TAR), a marker of trunk-predominant adiposity, was associated with BP. Survey-weighted multivariable linear regression and restricted cubic spline models were applied. TAR showed the strongest correlation with systolic BP (SBP) and diastolic BP (DBP) (r = 0.326 and 0.330, respectively; both p < 0.001). After adjustment for demographic and clinical covariates and either BMI or WC, TAR remained associated with higher SBP and DBP (p < 0.001). Additional adjustment for serum lipids modestly attenuated these associations, with triglycerides showing the largest attenuation. Higher TAR was consistently associated with higher predicted BP, supporting TAR as a useful adiposity index for hypertension research.