Research on the correlation between thyroid hormone sensitivity and cardiovascular autonomic neuropathy in patients with type 2 diabetes mellitus

Thyroid hormone is recognized as a pivotal hormone in the development and maintenance of normal neurological functions. However, there is currently a lack of research on whether thyroid hormone sensitivity affects cardiovascular autonomic neuropathy (CAN) in patients with type 2 diabetes mellitus (T2DM).

This study aims to investigate the relationship between them and can offer clinical predictive value for CAN in T2DM patients.

A total of 395 T2DM patients were selected. In addition to routine thyroid function tests, we also evaluated thyroid hormone sensitivity, including Thyroid Feedback Quantile Index (TFQI), Parameterized Thyroid Feedback Quantile Index (PTFQI), Thyroid-Stimulating Hormone Index (TSHI), Thyroxine Resistance Index (TT4RI), and FT3/FT4 ratio. Model regression analysis was employed to examine the association between thyroid hormone sensitivity and heart rate variability (HRV). Binary logistic regression was used to explore the risk factors of CAN. Receiver operating characteristic (ROC) curves were generated to assess the diagnostic accuracy of the thyroid hormone sensitivity indexes for identifying CAN in T2DM patients.

The present study has found that the risk of CAN is negatively associated with FT3/FT4 ratio (OR = 0.155, p = 0.009), while positively associated with TSHI (OR = 3.590, p = 0.016), TT4RI (OR = 1.073, p < 0.001), TFQI (OR = 7.789, p = 0.003), and PTFQI (OR = 4.341, p = 0.017) in T2DM patients. ROC curve analysis revealed that FT3/FT4 ratio and TFQI had higher accuracy in predicting CAN. The combination of FT3/FT4 ratio and TFQI showed superior diagnostic efficacy.

Impaired thyroid hormone sensitivity is associated with CAN in T2DM patients with normal thyroid function. FT3/FT4 ratio and TFQI can be used as auxiliary diagnostic tools for CAN in clinical T2DM patients, providing assistance in the management of CAN in T2DM patients.