Intrapancreatic Fat Deposition and Metabolic Signatures Across Adiposity Phenotypes in Chinese Adults: A Computed Tomography Analysis

AIMS: To investigate the associations between intrapancreatic fat deposition (IPFD), quantified by the pancreas-spleen attenuation difference (P-S Difference) on non-enhanced computed tomography (CT), and metabolic biomarkers in Chinese adults, and to distinguish direct and indirect effects of IPFD via body mass index (BMI) and metabolic dysfunction-associated steatotic liver disease (MASLD). MATERIALS AND METHODS: This single-centre, retrospective study analysed 558 Chinese adults (mean age 63.8 ± 13.6 years; 44.4% male). IPFD was quantified as the P-S Difference; lower values indicated greater IPFD. Missing data were handled by multiple imputation. Sequentially adjusted multivariable regression, restricted cubic splines, directed acyclic graph-informed mediation, and stratified analyses were performed. RESULTS: In the fully adjusted model, lower P-S Difference was independently associated with higher fasting plasma glucose (FPG; β = -0.0068, 95% CI -0.0136 to 0.0000; p = 0.049), triglycerides (TG; β = -0.0023, [-0.0043 to -0.0002]; p = 0.028), free fatty acids (FFA; β = -0.0012, [-0.0021 to -0.0003]; p = 0.012), and triglyceride glucose (TyG) index (β = -0.0028, [-0.0046 to -0.0010]; p = 0.002), and with lower high-density lipoprotein cholesterol (HDL-C; β = 0.0013, [0.0002 to 0.0024]; p = 0.025). Associations with clinical diagnoses (hypertension, metabolic syndrome, type 2 diabetes and coronary heart disease) were non-significant after adjustment. BMI mediated ≤ 7.1% of associations, whereas MASLD partially mediated TG (22.5%, p = 0.017) and TyG (15.7%, p = 0.019). CONCLUSIONS: IPFD was associated with an early metabolic signature, notably elevated TG, FFA, and TyG, independent of BMI and MASLD. Prospective validation is required.