Comparative discriminatory performance of emerging endocrine-metabolic indices versus obesity indices for cardiometabolic multimorbidity in older adults: a cross-sectional study

Study objectives: The objective of this study was to assess and compare the discriminatory performance of endocrine-metabolic and obesity indices for identifying cardiometabolic multimorbidity (CMM) in older adults. Methods: A total of 4,173 elderly people who participated in community physical examinations in a community hospital in Shandong Province, China in 2024 were included in this study. Obesity indicators include Body Roundness Index (BRI), Chinese Visceral Adiposity Index (CVAI), A Body Shape Index (ABSI) and Relative Fat Mass (RFM); Endocrine-metabolic indices include the Triglyceride/High-Density-Cholesterol (TG/HDL-C) ratio, Metabolic Score for Insulin Resistance (METS-IR), Triglyceride-Glucose (TyG) index and Atherogenic Index of Plasma (AIP). Multivariable logistic regression was used to examine associations with CMM, with quartile analyses for dose-response trends. Restricted cubic spline models were applied to assess potential nonlinearity. Discriminatory performance was evaluated using receiver operating characteristic (ROC) curves and area under the curves (AUCs), and AUCs were compared. Subgroup and sensitivity analyses were conducted to assess robustness. Results: In the fully adjusted model, all eight indices were all independently positively correlated with the risk of CMM, with significant dose-response trends across quartiles (all P for trend< 0.05). METS-IR showed the strongest risk gradient, with an OR of 6.79 (95% CI 4.85-9.52) comparing the fourth versus the first quartile. Restricted cubic spline analyses suggested largely linear associations for most indices, whereas TG/HDL-C and METS-IR exhibited significant nonlinear relationships, with steeper increases in CMM risk at higher levels. In ROC analyses, endocrine-metabolic indices generally demonstrated higher discriminatory performance than obesity indices. METS-IR yielded the highest adjusted AUC (0.685), followed by TyG (AUC 0.664). Among obesity indices, CVAI showed comparatively better performance (AUC 0.646). Subgroup and sensitivity analyses yielded consistent results. Conclusions: In this community-based sample of older adults, endocrine-metabolic indices showed relatively stronger associations and generally better discriminatory performance for CMM than obesity indices. METS-IR demonstrated the most favorable overall performance and may be a practical indicator for identifying older individuals at increased risk of CMM in routine community health examinations.