Kayoung Lee
Body mass index (BMI) is widely used to assess obesity-related cardiometabolic risk, but the adiposity measures corresponding to a given BMI may differ across populations. We hypothesized that in Korean adults, a BMI of 25 kg/m² would correspond to substantial metabolic syndrome (MetS) risk at lower adiposity levels than previously reported in Western populations and that BMI and adiposity measures would demonstrate differential discriminatory performance for MetS. We analyzed adults aged 18-80 years from the Korea National Health and Nutrition Examination Survey were analyzed, including 3023 participants with dual-energy X-ray absorptiometry (DXA)-derived whole-body fat percentage (WBF%) and trunk fat percentage (2008-2011) and 9185 participants with bioelectrical impedance analysis (BIA)-derived WBF% (2022-2023). Age- and sex-adjusted complex-sample logistic regression was used to estimate the probability of MetS at BMI 25 kg/m² and the corresponding adiposity measures. The estimated prevalence of MetS at BMI 25 kg/m² was 29.6% in DXA-based dataset and 29.7% in BIA-based dataset. Corresponding WBF% values were 22.3% in men and 33.2% in women in DXA-based dataset, and 24.7% and 33.2%, respectively, in BIA-based dataset. Corresponding trunk fat percentages were 24.4% in men and 33.2% in women. BMI demonstrated greater discriminatory performance for MetS than WBF% in both datasets, and trunk fat percentage outperformed WBF% in DXA dataset. These findings support the hypothesis that Korean adults experience substantial metabolic risk at lower adiposity levels than reported in U.S. populations and highlight the importance of considering both total and regional adiposity in nutritional and metabolic risk assessment.