Pericoronary, but Not Epicardial, Cardiac Fat Thickness Is Associated with Sarcopenia in Hospitalized Older Adults

Background and Objectives: Sarcopenia is a major geriatric condition associated with functional decline and adverse outcomes. Cardiac fat depots exhibit metabolic activity and are linked to cardiometabolic risk; however, the extent to which epicardial adipose tissue (EAT) and pericoronary adipose tissue (PCAT) quantified on standard thoracic computed tomography (CT) scans are associated with sarcopenia in older inpatients remains inadequately explored. This study investigated the associations of EAT and PCAT thickness with sarcopenia. Materials and Methods: This is a retrospective observational study using CT data obtained for clinical purposes and routine geriatric assessment data. In this single-center retrospective study, 101 inpatients aged ≥65 years who underwent unenhanced thoracic CT and bioelectrical impedance analysis within 3 months were included. EAT and PCAT thicknesses were measured using standardized methods. Sarcopenia status was based on a previously established clinical diagnosis according to EWGSOP2 criteria. Multivariable logistic regression, body mass index (BMI)-stratified analyses, and ROC curve evaluations were performed. Results: The participants had a mean age of 78.5 ± 7.6 years; 54.5% were female. Fifty-five patients (54.5%) met the diagnostic criteria for sarcopenia. PCAT was significantly thicker in sarcopenic participants relative to non-sarcopenic ones (12.25 ± 2.50 vs. 11.17 ± 2.32 mm, p = 0.028), while no corresponding difference was observed for EAT (p = 0.959). After controlling for age, sex, and BMI, each 1 mm increase in PCAT thickness was independently associated with an increased odds of sarcopenia (OR 1.399, 95% CI 1.133-1.727, p = 0.002). With the addition of the PCAT, the discriminatory power was modest (AUC 0.637 overall and 0.715 for BMI ≥25 kg/m²). In exploratory stratified analyses, the association was numerically larger in the BMI ≥25 kg/m² subgroup (OR 1.48, p = 0.008); however, the formal BMI-by-PCAT interaction was not statistically significant (p = 0.290), so this subgroup finding is considered hypothesis-generating. Conclusions: PCAT thickness measured on routine non-contrast thoracic CT was associated with prevalent sarcopenia, whereas EAT thickness was not. ROC analyses showed modest discrimination; therefore, any proposed cut-offs should be considered exploratory and require prospective validation and external confirmation before clinical use.