Alterations of Thyroid Hormone Levels and the Risks of Diabetic Retinopathy in T2DM

Abstract

Background: Diabetes mellitus and thyroid disease are linked endocrinopathies. The association between diabetes mellitus complications and thyroid function is characterized by a complicated interdependent interplay that is difficult to understand. Objective: We conducted this study to determine the association between diabetic retina disease (DRD) incidence and normal thyroid hormone levels in T2DM. Methods: Recruit patients in the study, 134 patients with type 2 diabetes and 36 healthy ones with no DM, were screened in the present case-control study. Diabetic retinopathy was tested for all patients, and anthropometric and thyroid functions were assessed. Regression analyses were employed to evaluate the relationship between thyroid hormones and the risk of developing DR. Results: There were significant differences in triiodothyronine (T3) and thyroxine (T4) serum levels among the DR groups and the healthy control. The levels in each TSH and T4 are positively significant between groups of PDR and NDR, while T3 was negatively associated with NPDR. A significant association was found between increasing levels of T3 and the development of severe DR; thus, PDR was less likely to occur in individuals with high T3 levels‎ [OR 0.014(95% CI, 0.001-0.34) P value is 0.009 after adjustment. The risk of PDR had an increased likelihood of developing PDR at the highest levels of serum TSH and T4 [OR 41.07(1.60-1053.1) P= 0.025, OR 65.91(2.10-2067) P= 0.017, respectively). Conclusion: Diabetes retinopathy in euthyroid Iraqi people may be associated with levels of T3 and T4 in the blood. Patients with higher TSH and T4 concentrations had a greater risk of developing sight-threatening PDR in type 2 diabetics.