Association and Discriminative Performance of a Body Shape Index (ABSI) for Cardiometabolic Disease in a Korean Population.

Background/Objectives: A body shape index (ABSI) has been proposed as an anthropometric measure reflecting abdominal body shape beyond body mass index (BMI). However, its relative cross-sectional discriminative ability compared with conventional anthropometric measures and surrogate markers of insulin resistance for prevalent diabetes and cardiovascular disease (CVD) remains poorly characterized in Korean adults. Methods: This cross-sectional study included 11,448 Korean adults aged 18-64 years from the 2019-2021 Korean National Health and Nutrition Examination Survey (KNHANES). Using receiver operating characteristic (ROC) curve analyses, we compared the discriminative ability of ABSI with BMI, waist circumference, waist-to-height ratio, homeostatic model assessment for insulin resistance (HOMA-IR), triglyceride-to-HDL cholesterol ratio (TG/HDL-C), and the triglyceride-glucose index (TyG) for prevalent diabetes and CVD. Multivariable logistic regression analyses assessed associations after adjustment for demographic and socioeconomic factors. Results: ABSI showed the highest ROC-AUC for both prevalent diabetes (74%) and CVD (74%) among the compared indices. In multivariable-adjusted analyses, individuals in the very high ABSI risk group had higher odds of prevalent CVD (OR, 3.75; 95% CI, 1.60-8.78) than those in the very low-risk group. Among individuals with diabetes, the odds of comorbid CVD were also higher in the very high ABSI group (OR, 3.38; 95% CI, 2.26-5.07). Similar patterns appeared in obesity-subgroup analyses. Conclusions: ABSI showed greater discriminative ability for prevalent diabetes and CVD than several conventional measures and insulin-resistance markers, supporting its potential utility as a simple marker of cardiometabolic disease burden. Prospective studies are needed to determine its prognostic value.