Anti-thyroid Peroxidase Antibody Positivity and Chronic Hyperglycemia as Key Risk Factors for Peripheral Artery Disease in Type 2 Diabetes: A Retrospective Cohort Study

BACKGROUND: Anti-thyroid peroxidase antibody (TPOAb) affects metabolic and thyroid function parameters, which may worsen macrovascular complications. This study aims to find the association between chronic hyperglycemia, thyroid autoantibody, and peripheral artery disease (PAD) in type 2 diabetes mellitus (T2DM) patients, as well as examine important clinical demographic and metabolic variables. METHODS: This is a retrospective cohort study. Data from 2017-2023 of T2DM patients were collected. A total of 300 patients were included. Further, the T2DM patients are subdivided by TPOAb values. TPOAb categorized (0-60 IU/mL) as negative; TPOAb titer (>60 IU/mL) as positive. To analyze the data, IBM SPSS Statistics for Windows, Version 29.0.2.0 (Released 2022; IBM Corp., Armonk, New York, United States) was utilized. For continuous variables, the independent samples t-test for normally distributed data and the Mann-Whitney U test for non-normally distributed data were performed. The chi-square test was used to assess the association between categorical variables. The risk of PAD was assessed using univariate and multivariate binary logistic regression analysis. P<0.05 was set as statistically significant. RESULTS: The prevalence of PAD was significantly higher in the TPOAb-positive group (38.5%) compared to the TPOAb-negative group (21.6%, p = 0.004). Multivariate analysis finds that poorly controlled HbA1c had an increased risk of PAD compared to well-controlled individuals (OR: 2.14, p = 0.046). Those who had diabetes for >10-15 years showed the highest risk (OR: 3.67, P = 0.002), followed by those with diabetes for more than 15 years (OR: 2.22, P = 0.038). Similarly, TPOAb positivity was independently correlated with increased odds of PAD (OR: 2.48, P = 0.003) and therefore potentially heightened the risk of macrovascular complications in association with thyroid autoimmunity. CONCLUSION: TPOAb positivity is associated with an increased risk of PAD. In addition, poor glycemic control and longer diabetes duration were associated with PAD.