Association of pericoronary fat attenuation index and insulin resistance for the risk of cardiometabolic multimorbidity: a cross-sectional study

Background: Cardiometabolic multimorbidity (CMM) has become an increasingly serious public health problem. Patients with type 2 diabetes mellitus (T2DM) often present with multiple cardiometabolic disorders and carry a significantly higher risk of CMM. Insulin resistance (IR) is the core mechanism of T2DM and atherosclerotic cardiovascular disease. The triglyceride-glucose index (TyG index) can serve as a reliable alternative for evaluating IR. The pericoronary fat attenuation index (FAI) is a non-invasive biomarker of coronary inflammation based on coronary CT angiography. However, the combined associations of the TyG index and FAI with CMM among patients with T2DM remain unknown. Therefore, this study aims to evaluate the TyG index, RCA-FAI, LAD-FAI, and LCX-FAI in relation to CMM among middle-aged and elderly patients with T2DM in China. Method: We conducted a cross-sectional study and enrolled 497 middle-aged and elderly patients (aged ≥45 years) with T2DM who underwent coronary CT angiography for clinical indications. We defined CMM as the concurrent presence of T2DM together with coronary heart disease or stroke. We used a multivariate logistic regression model to analyze the association between the TyG index and the FAI in each coronary segment (including RCA-FAI, LAD-FAI, and LCX-FAI) with CMM. We presented the study results as odds ratios (ORs) with their corresponding 95% confidence intervals (CIs). We employed restricted cubic splines to analyze the nonlinear relationship and used receiver operating characteristic (ROC) curves to assess the discriminatory capacity of each index in identifying CMM. Result: < 0.001). In contrast, adding the TyG index did not meaningfully improve the predictive value of the baseline clinical model. Conclusion: This study confirms that among middle-aged and elderly Chinese patients with T2DM, both the TyG index and FAI, including RCA-FAI, LAD-FAI, and LCX-FAI, are independently and positively associated with CMM. However, only coronary FAI indices significantly improve the discriminatory capacity for CMM, with RCA-FAI showing the strongest association and incremental predictive value. These findings suggest that FAI could serve as a useful imaging biomarker for identifying CMM status in patients with T2DM.