Comparative Analysis of Surrogate Insulin Resistance Indexes in Cardiometabolic Multimorbidity: A Cross-Sectional Study

Background:Cardiometabolic multimorbidity (CMM), defined as the coexistence of two or more cardiometabolic diseases, poses an increasing challenge to global health. Although various surrogate indexes of insulin resistance (IR) exist, current evidence lacks a systematic comparison of the related strength of association with CMM. Therefore, this study aimed to systematically evaluate 12 IR surrogates to determine the associated discriminative ability for detecting CMM.Methods:The analytical cohort comprised 9756 eligible participants from the National Health and Nutrition Examination Survey (NHANES) conducted between 1999 and 2020. The 12 IR surrogates were examined using multivariable logistic regression to assess the related associations with CMM. Nonlinear relationships were examined with restricted cubic splines, and discriminatory power was evaluated through the area under the curve (AUC) from receiver operating characteristic (ROC) analysis.Results:Among 9756 eligible participants, 4383 (44.9%) were identified with CMM. Multivariable logistic regression-adjusted models revealed that odds ratios (ORs) for CMM progressively increased with ascending quartiles of all IR surrogates. After full adjustment, the ORs of homeostatic model assessment of insulin resistance (HOMA-IR) were as follows: Q2: OR = 1.78, 95% confidence interval (CI): 1.48–2.14; Q3: OR = 3.60, 95% CI: 2.82–4.60; Q4: OR = 8.80, 95% CI: 7.31–10.60. For triglyceride-glucose (TyG)-a body shape index (TyG-ABSI), the corresponding ORs were: Q2: OR = 2.51, 95% CI: 2.04–3.11; Q3: OR = 4.93, 95% CI: 3.98–6.10; Q4: OR = 11.02, 95% CI: 8.86–13.71. Nonlinear associations were observed for 11 of the 12 IR indexes, whereas TyG-ABSI exhibited linear dose–response relationships. TyG-ABSI outperformed other markers in the ROC analyses with an AUC of 0.764. These findings remained robust across multiple sensitivity analyses.Conclusions:TyG-ABSI is a reliable and cost-effective indicator associated with CMM risk, supporting the subsequent utility in distinguishing higher-risk individuals.