Association of non-insulin-dependent insulin resistance indices with lower limb artery restenosis after drug-coated balloon angioplasty.

Background: This study aimed to investigate the associations between noninsulin-dependent insulin resistance indices (NI-IRIs), including the triglyceride-glucose (TyG) index, TyG-BMI, triglyceride-to-high-density lipoprotein cholesterol ratio (TG/HDL-C), and metabolic score for insulin resistance (METS-IR), as well as the occurrence of restenosis in patients with lower extremity atherosclerotic occlusive disease after drug-coated balloon (DCB) treatment.

Methods: The primary endpoint was restenosis within one year after the procedure, which was defined as ≥ 50% stenosis of the treated artery segment. The association between NI-IRIs and restenosis was assessed via multivariable logistic regression analysis. Restricted cubic spline (RCS) analysis was performed to quantify nonlinearity. The consistency of these associations was confirmed through subgroup and interaction analyses. Additionally, the additional predictive value of NI-IRIs beyond established risk factors for restenosis was evaluated via receiver operating characteristic (ROC) curves, the net reclassification improvement (NRI), and integrated discrimination improvement (IDI) indices.

Results: Except for the TyG index, the other three NI-IRIs demonstrated nonlinear relationships with the probability of postoperative restenosis. Specifically, TG/HDL-C (inflection point: 1.48, P for nonlinearity: 0.003) exhibited a saturating effect, whereas METS-IR (inflection point: 49.30, P for nonlinearity: 0.017) and TyG-BMI (inflection point: 221.53, P for nonlinearity: 0.039) showed threshold effects. Subgroup analysis revealed that the interactions among the subgroups were not statistically significant. Furthermore, among the four NI-IRIs, the addition of the TG/HDL-C index significantly enhanced the predictive power of the base model for restenosis in ASO patients following DCB angioplasty (AUC values: 0.726 vs. 0.760, P = 0.042). The P values for the NRI and IDI were 0.001 and 0.002, respectively.

Conclusion: TG/HDL-C showed a saturating effect on restenosis within one year after DCB treatment in ASO patients, and METS-IR and TyG-BMI showed threshold effects. The addition of the TG/HDL-C index significantly improved the predictive ability of the base model for restenosis in ASO patients who underwent DCB angioplasty.