Serum free triiodothyronine is inversely associated with diabetic peripheral neuropathy but not with carotid atherosclerotic lesions in euthyroid patients with type 2 diabetes

Abstract

Background The associations between serum free triiodothyronine (FT3) and diabetic peripheral neuropatprohy (DPN)/carotid atherosclerotic lesions in euthyroid patients with type 2 diabetes are still unclear. The purpose of our study was to explore the relations of FT3 to DPN and carotid atherosclerotic lesions in Chinese type 2 diabetes inpatients with euthyroid function. Methods 2477 euthyroid inpatients with type 2 diabetes were recruited and they were stratified into quartiles by FT3 levels in this cross-sectional study. Peripheral neuropathy was assessed by neurological symptoms and signs as well as nerve conduction velocity tests. Carotid atherosclerotic lesions, including carotid intima-media thickness, plaque and stenosis, were evaluated by Doppler ultrasound. Results The prevalence of DPN in type 2 diabetic patients exhibited the significant decrease across the FT3 quartiles (23.5%, 20.9%, 18.8%, and 11.2%, respectively, p < 0.001). Multiple logistical regression analysis also revealed that FT3 quartiles were significantly and inversely associated with DPN. Compared with the subjects in the highest FT3 quartile, the adjusted odds ratios (95% confidence interval) of DPN from the first to third FT3 quartile were successively 2.338 (1.407–3.884), 1.903 (1.134–3.194) and 1.598 (0.960–1.125). The patients with DPN had significantly higher prevalence of carotid atherosclerotic lesions compared with non-DPN patients. However, no statistical association was observed between FT3 quartiles and carotid atherosclerotic lesions after adjusting for confounder factors. Conclusions Lower FT3 within the normal range was independently associated with DPN, but not with carotid atherosclerotic lesions in Chinese euthyroid inpatients with type 2 diabetes.

Correlation of thyroid-related hormones with vascular complications in type 2 diabetes patients with euthyroid

“…Previous studies have shown that fT3 level was negatively associated with risk of abnormal nerve conduction (56). Meanwhile, Li et al demonstrated a negative association of fT3 with DPN in T2DM patients with normal thyroid function (57). This is consistent with our findings.…”

Evaluation of the Thyroid Characteristics and Correlated Factors in Hospitalized Patients with Newly Diagnosed Type 2 Diabetes

“…Cross-sectional studies showed that subclinical hypothyroidism was highly prevalent in patients with DR and DPN, and was closely related to their severity. [44][45][46] Low FT3 within the normal range was also indicated to be independently associated with DR 10 and DPN 47 in euthyroid patients with T2DM in recently researches. But notably, the relationships between thyroid hormone levels and diabetic microvascular complications such as DR were found to be weak or negative in some researches 48 and there is a lack of large-scale prospective clinical research on the impact of thyroid on the occurrence and course of diabetic chronic complications.…”

FT3/FT4 ratio in a certain range identified as an independent protective factor for glycemic variability in patients with type 2 diabetes

“…Thyroid dysfunction and diabetes mellitus are closely linked [10] , while normal thyroid hormone is also associated with macrovascular and microvascular complications in type 2 diabetes [11][12][13][14][15] , but the speci c mechanisms are still unclear. We speculated that the uctuations of thyroid hormones in uenced glycemic variability, and the increased glycemic variability contributed to various complications.…”