The triglyceride-glucose index and C-reactive protein-triglyceride-glucose index as surrogate markers of vascular stiffness in prediabetes: a cross-sectional study

Prediabetes accelerates arterial stiffening, yet the optimal metabolic biomarker for vascular assessment remains undetermined. This study investigated the associations of the homeostasis model assessment of insulin resistance (HOMA-IR), triglyceride-glucose (TyG) index, and C-reactive protein-triglyceride-glucose index (CTI) with arterial stiffness in a prediabetic population. This cross-sectional study enrolled 2,008 prediabetic adults. Arterial stiffness was defined by brachial-ankle pulse wave velocity (baPWV). Multivariable logistic regression, restricted cubic spline (RCS) modeling, and ROC curve analyses were employed to evaluate and compare the discriminatory performance of HOMA-IR, TyG, and CTI. All three indices were independently associated with arterial stiffness. Fully adjusted odds ratios (ORs) per one-unit increment were 1.12 (1.04–1.21) for HOMA-IR, 1.49 (1.24–1.80) for TyG, and 1.52 (1.25–1.85) for CTI. Comparing the highest to the lowest quartiles, the ORs for arterial stiffness were 1.84 ( 1.31–2.59) for HOMA-IR, 2.02 (1.44–2.82) for TyG, and 1.72 (1.23–2.39) for CTI, respectively. RCS analysis revealed a nonlinear relationship for HOMA-IR, whereas TyG and CTI exhibited linear dose-response patterns. ROC analyses based on adjusted prediction models showed that CTI had the numerically highest discriminatory performance (AUC = 0.790), followed closely by TyG (AUC = 0.784), whereas HOMA-IR showed lower discrimination (AUC = 0.737). Pairwise DeLong tests showed that CTI provided a modest but statistically significant improvement over TyG ( P = 0.041), while both CTI and TyG significantly outperformed HOMA-IR (both P < 0.001). Findings remained robust across subgroup and sensitivity analyses. HOMA-IR, TyG, and CTI are independent risk indicators for arterial stiffness in prediabetes. Notably, TyG and CTI exhibit stronger associations and superior discriminatory utility compared to HOMA-IR. These simple, accessible metabolic indices—particularly TyG and CTI—serve as robust practical surrogate markers for identifying prevalent arterial stiffness in individuals with prediabetes.