1452-P: Adipose Tissue Insulin Resistance: Associated Factors and Sex Differences across Obesity and Dyslipidemia Status

Introduction and Objective: Adipose tissue insulin resistance(IR) is related with metabolic disorders. However, evidence regarding sex differences in adipose IR remains limited. This study aimed to identify factors associated with adipose IR and to examine sex differences and their potential modifiers. Methods: This cross-sectional study included 9,935 adults undergoing routine physical examinations. Adipose IR index(Adipo-IR) was calculated as the product of the fasting insulin and free fatty acid concentration. Multivariable linear regression models were used to identify independent predictors of Adipo-IR after adjustment for potential confounders, and effect modification of sex differences was assessed. Adipo-IR was log-transformed, and age was modeled using natural cubic splines with four degrees of freedom. Results: Female sex(β=0.25, P<0.001), higher BMI, hyperlipidemia (β=0.18, P<0.001), hypertension(β=0.14, P<0.001), hyperuricemia(β=0.16, P<0.001), and diabetes(β=0.32, P<0.001) were independently associated with higher Adipo-IR after adjustment for other confounders. Overall, women exhibited higher Adipo-IR than men. This sex difference progressively attenuated across BMI categories, with differences of 1.32, 1.29, and 1.18 units (μIU/mL*mmol/L) for BMI <24, 24 to <28, and ≥28 kg/m², respectively (P for interaction=0.014). A similar attenuation was observed by lipid status, with differences of 1.36 units in normolipidemic participants and 1.23 units in those with hyperlipidemia(P for interaction<0.001). Age demonstrated a U-shaped association with Adipo-IR both in women and men(P for non-linearity<0.001). Adipo-IR declined with increasing age before 52.7 years and increased thereafter. Conclusion: Adipose IR is closely linked to multiple metabolic risk factors and displays distinct age- and sex-specific patterns. The sex difference in Adipose IR was attenuated with increasing obesity and in the presence of hyperlipidemia.