Central Adiposity and Cardiometabolic Risk in Occupational Personnel: Nonlinear Associations with Lipid Risk and Aerobic Capacity.

OBJECTIVE: To examine whether DXA-derived android-to-gynoid fat ratio (A/G) relates to cardiometabolic risk and aerobic capacity in first responders beyond BMI-based phenotypes. METHODS: In this cross-sectional study, 170 first responders were categorized into four BMI-body fat phenotypes. Group differences in VO₂peak, A/G, and cardiometabolic markers were examined using ANCOVA. A/G was modeled continuously using linear regression, generalized additive models, and exploratory structural equation modeling. RESULTS: VO₂peak, TG/HDL, and estimated pulse wave velocity differed across phenotypes. A/G showed nonlinear associations with TG/HDL (edf = 3.22, F = 13.7, p < 0.01) and AOPP (edf = 2.89, F = 5.25, p < 0.01). A/G showed a modest nonlinear association with VO₂peak, but indirect pathways were unsupported. CONCLUSIONS: Central adiposity may better reflect cardiometabolic heterogeneity than aerobic capacity in first responders.