Abstract
PURPOSE: This study explored the relationship between thyroid hormone sensitivity and peripheral arterial disease (PAD) in type 2 diabetes mellitus (T2DM) patients with euthyroid, in order to identify potential factors for preventing PAD. PATIENTS AND METHODS: A retrospective examination was conducted on 491 type 2 diabetes mellitus patients with euthyroid between October 2021 and June 2024. Based on an ankle-brachial index (ABI) ≤ 1.0, subjects were categorized into two distinct cohorts: PAD group (n = 147) and no peripheral arterial disease (NPAD) group (n = 344). In order to evaluate their responsiveness to thyroid hormone, we calculated several indexes: thyroid feedback quantile-based index (TFQI), thyroid-stimulating hormone index (TSHI), thyrotroph T4 resistance index (TT4RI), and free triiodothyronine/free thyroxine (FT3/FT4). Then we conducted multivariate logistic regression analysis and the analysis of the operating characteristic curve of the subjects to determine the accuracy of these indicators in predicting PAD. RESULTS: Significant differences were observed in thyroid hormone sensitivity indices across the PAD and NPAD groups. Logistic regression, adjusted for various covariates, identified higher thyroid hormone sensitivity indices (TFQI, TSHI, and TT4RI) and lower FT3/FT4 as predictive of PAD. Moreover, Spearman correlation analysis confirmed these findings, demonstrating positive associations between TFQI, TSHI, TT4RI and PAD, while the FT3/FT4 ratio showed an inverse relationship with the condition. The integrated thyroid sensitivity indices model (covariate-adjusted) achieved a PAD prediction AUC of 0.628 (95% CI 0.575-0.691), featuring 55.5% specificity and 63.9% sensitivity. CONCLUSION: Reduced central and peripheral thyroid hormone sensitivity independently predicts PAD risk in T2DM patients with euthyroid.