Abnormalities in Thyroid Function and Morphology in Chronic Hemodialysis Patients

Background: The kidney has an important role in the metabolism of thyroid hormones. Impaired renal function and the resulting accumulation of uremic toxins may disturb thyroid physiology at various levels. The prevalence of goiter and thyroid nodules is significantly increased in patients with ESRD compared with other hospitalized patients admitted for treatment of non-renal disease. The purpose of this study was to assess thyroid dysfunction and thyroid morphology in patients with ESRD on regular maintenance hemodialysis. Methods: Thyroid function tests (TSH, free T 3 and free T4) and thyroid gland ultrasound imaging were assessed before hemodialysis in 40 ESRD patients treated with regular maintenance hemodialysis compared to 20 healthy matched controls for age and gender. Results: Plasma levels of free T3 and free T4 were significantly lower and TSH levels were insignificantly higher in hemodialysis patients compared to controls. Thyroid gland volume and thyroid lesions (nodules and cysts) are clearly increased in hemodialysis patients. Logistic regression analysis revealed no relationship between thyroid abnormalities and age, gender, BMI or duration of dialysis. Conclusion: Our results revealed that ESRD patients on regular maintenance hemodialysis have a higher prevalence of alteration of thyroid function (low free T 3 and free T 4). Also, thyroid lesions (cysts and nodules) and thyroid gland volume were clearly increased compared to healthy controls.