Endocrine Abstracts

Introduction: The prevalence of diabetes mellitus (DM) continues to increase worldwide. Diabetic retinopathy (DRP) is one of the most common complications of Type 2 DM. Recently, the effect of thyroid hormones on diabetic microvascular complications has gained much attention. This relationship is explained by the important effects of thyroid hormones on endothelial function. There are studies investigating the relationship between TSH and diabetic nephropathy and DRP. There are very few studies evaluating free thyroid hormone levels. In this study, it was aimed to investigate the relationship between free thyroid hormone levels and DRP in euthyroid patients with type 2 DM.

Method: In this study, the biochemical records of patients with Type 2 DM who had euthyroid status and evaluated for retinopathy, applied to the endocrinology and ophtalmology clinics of our hospital between January 2018 and August 2018. Demographic data of the patients and characteristics that may be associated with diabetic retinopathy were evaluated. Whether the patients had DRP and, if any, retinopathy levels were recorded. It was evaluated whether there was a difference in free thyroid hormone levels between the groups with and without DRP.

Results: A total of 171 patients, 106 men and 65 women, were included in the study. Mean age was 57.19 ±10.81 years. DRP was not present in 127 patients (74.2%), nevertheless 36 patients (21%) had nonproliferative DRP and 8 patients (4.6%) had proliferative DRP. There was no difference between the groups in terms of age, gender, hypertension, cardiovascular disease, fasting plasma glucose, serum creatinine, lipid levels and microalbuminuria. The duration of diabetes was longer in the nonproliferative DRP group (P=0.026). HbA1c levels were higher in the proliferative DRP group (P=0.05). No significant difference was found in terms of TSH levels and free thyroid hormone levels in all three groups.

Conclusion: In our study, the relationship between free thyroid hormone levels and DRP in euthyroid type 2 DM patients was investigated. Diabetes duration and Hba1c levels were found to be risk factors in DRP similar to the literature. When the groups with and without DRP were compared, no difference was found in TSH and free T4 and free T3 levels.