A retrospective study of correlation between insulin resistance surrogate indexes, inflammatory markers, and peripheral arterial disease in type 2 diabetes mellitus

Background This study aimed to investigate the correlation between six surrogate indexes of insulin resistance (IR) and six inflammatory markers with diabetic peripheral arterial disease (DPAD) in patients with type 2 diabetes mellitus (T2DM). Methods Clinical and hematological data were retrospectively collected from 300 patients with T2DM admitted to the Endocrinology Department of Wuhu Hospital of Traditional Chinese Medicine (Anhui, China) between January 2024 and May 2025. Patients were divided into two groups: DPAD ( n = 207) and T2DM (without DPAD ( n = 93)). IR surrogate indexes analyzed included estimated glucose disposal rate (eGDR), Chinese Visceral Adiposity Index (CVAI), triglyceride-glucose (TyG) index, TyG-body mass index (TyG-BMI), metabolic score for insulin resistance (METS-IR), and atherogenic index of plasma (AIP). Inflammatory markers assessed included neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), total cholesterol-to-lymphocyte ratio (TCLR), fibrinogen-to-lymphocyte ratio (FLR), lymphocyte-to-monocyte ratio (LMR), and systemic immune-inflammation index (SII). Factors associated with DPAD were identified and the discriminative ability of IR surrogate indexes and inflammatory markers for DPAD was explored. Results Compared with the T2DM group, the DPAD group exhibited significantly higher CVAI, TyG-BMI, METS-IR, AIP, NLR, PLR, TCLR, FLR, and SII ( p < 0.05), while eGDR and LMR were significantly lower ( p < 0.05). Logistic regression analysis revealed that CVAI, TyG-BMI, METS-IR, AIP, NLR, PLR, FLR, and SII were positively associated with DPAD, whereas eGDR and LMR were inversely associated. eGDR and FLR exhibited significant associations with DPAD in sex and age subgroups. Receiver operating characteristic (ROC) curve analysis revealed that the combined eGDR+CVAI+FLR+LMR model yielded the highest area under the ROC curve (AUC) of 0.742 (95% CI [0.681–0.803]). Conclusion IR surrogate indexes and inflammatory markers are closely associated with DPAD risk in T2DM patients. The combined eGDR+CVAI+FLR+LMR model showed the best discriminative ability for DPAD, offering a potential reference for early clinical identification. These findings, however, are hypothesis-generating and require validation in prospective studies.