Effects of 1-year growth hormone replacement therapy on thyroid volume and function of the children and adolescents with idiopathic growth hormone deficiency

Background: There are different opinions about the effects of growth hormone replacement therapy (GHRT) on thyroid function and volume. This study aimed to assess the effects of GHRT on thyroid volume and function in the children and adolescents with growth hormone (GH) deficiency. Methods: A total of 29 patients diagnosed with GH deficiency were enrolled in the study. The control group consisted of 29 cases matched for age, gender and pubertal period with the patients. Thyroid function tests and insulin-like growth factor levels were measured, simultaneously thyroid volumes were assessed by ultrasonography at the initiation period and at the end of GHRT. Results: Thyroid volumes of the patient group was -0.55 +/- 1.1 standard deviations (SDs) initially; whereas at the end of 1 year it was found to be -0.29 +/- 1.29 SDs and both SDs of thyroid volumes did not differ significantly. The SDs of thyroid volume of the control group was -0.85 +/- 1.03 SDs initially and -0.72 +/- 0.85 SDs at the end of 1 year; and they did not differ significantly. On the other hand, after GHRT of 1 year, thyroid stimulating hormone (TSH) and free thyroxine (T4) levels decreased. Conclusions: It was observed that SDs of thyroid gland volumes did not change in GH deficient children and adolescents after GHRT.