ESPE Abstracts

Introduction: Hypothyroidism in children leads to growth retardation. However, there is some evidence that recombinant human growth hormone (rhGH) therapy could suppress thyroid function. The actual incidence is controversial, however, with some studies showing a rare and others a high occurrence.

Aim and Methods: This study examines the effects of Growth Hormone (GH) therapy on thyroid function, specifically focusing on Free Thyroxine (FT4) and Thyroid Stimulating Hormone (TSH) levels, in children with Growth Hormone Deficiency (GHD) and Idiopathic Short Stature (ISS). The participants were divided into three distinct groups: those receiving GH treatment (n = 90), ISS patients undergoing GH treatment (n = 16), and a control group without treatment (n = 25). The study measured FT4 and TSH levels at baseline (T0) and after one year (T1) of GH therapy.

Results: In the GH-treated GHD group, the mean FT4 level showed a minor decrease from 15.94 to 15.53pmol/L, while the mean TSH level increased from 2.66 to 3.23mIU/L. Additionally, the standard deviation for TSH at T1 indicated a rise in variability (SD: 4.02). Initially, 4 out of 90 children had elevated TSH, and 2 had reduced FT4. Post one year of GH therapy, 4 additional children developed elevated TSH, and 2 more had reduced FT4. For the ISS-treated group, the mean FT4 reduced from 13.48 to 12.75pmol/L, with mean TSH showing stability (2.32 to 2.33mIU/L). The non-treated group experienced a notable decrease in mean FT4 from 14.96 to 13.51pmol/L, alongside a decrease in mean TSH from 2.73 to 1.60mIU/L. These findings indicate that GH therapy in children with GHD and ISS can significantly impact thyroid function, evidenced by the increased variability in TSH and a decrease in FT4 levels. Regular monitoring of thyroid function is essential during GH therapy, as these hormonal changes could have critical implications on the growth and development of affected children.