Related Experiment Videos
Changes of thyroid function during long-term hGH therapy in GHD children. A possible relationship with catch-up
S Seminara1, S Stagi, L Candura
1Department of Paediatrics, University of Florence, Anna Meyer Children's Hospital, Via Luca Giordano 13, Florence, Italy. seminara@unifi.it
Insights
Long-term recombinant human growth hormone (hGH) treatment in children with growth hormone deficiency (GHD) causes temporary thyroid function changes. These transient effects on thyroid hormones likely contribute to catch-up growth and resolve within two years.
Area of Science:
- Pediatric Endocrinology
- Hormone Therapy
- Metabolic Research
Background:
- Growth hormone (GH) therapy in children with GH deficiency (GHD) can alter thyroid function.
- Previous studies on these thyroid changes are limited by short follow-up periods (≤1 year).
Purpose of the Study:
- To investigate the long-term effects of recombinant human GH (hGH) on thyroid function in children with idiopathic GHD.
- To assess the clinical significance of these thyroid function alterations over a 24-month period.
Main Methods:
- A 24-month prospective study involving 19 prepubertal children with idiopathic GHD and 19 healthy controls.
- Thyroid hormone levels (TT3, FT3, TT4, FT4, TSH) and Growth Velocity Standard Deviation Scores (SDS-GV) were monitored.
- Statistical analysis, including multiple regression, was used to identify predictors of growth response.
Main Results:
- Significant, transient increases in TT3 and FT3 were observed within the first year of hGH treatment, followed by decreases.
- Thyroid hormone ratios (TT3/TT4, FT3/FT4) initially increased and then normalized.
- The TT3/TT4 ratio at 12 months was a significant predictor of SDS-GV, indicating a link between thyroid hormone metabolism and growth response.
Conclusions:
- Long-term hGH therapy in GHD children induces temporary changes in peripheral thyroid hormone metabolism.
- These thyroid function alterations are likely transient, resolving by the second year of treatment.
- The observed changes may play a functional role in mediating catch-up growth during hGH therapy.
Background:
Growth hormone (GH) treatment in patients with GH deficiency (GHD) can determine changes in the thyroid function. The clinical significance of these changes remains controversial, and all studies have so far covered rather a short period--usually no longer than one year.
Objective:
To determine the effect of long-term recombinant hGH treatment in children with idiopathic GHD on the thyroid function.
Patients And Methods:
Nineteen prepubertal children (12 boys and 7 girls, mean age 9.2 +/- 3.1 years) with idiopathic GHD were studied and followed for twenty-four months. None of the patients showed multiple pituitary hormone deficiencies. Nineteen healthy children matched for age and sex acted as controls.
Results:
Patients with GHD showed a significant increase in TT (3) at twelve months and in FT (3) at six and twelve months after starting GH treatment, with a significant decrease at eighteen and twenty-four months. TT (4) level decreased significantly at twelve months and increased significantly at eighteen and twenty-four months. FT (4) also decreased, but only slightly, after twelve months of hGH treatment, and then increased significantly at twenty-four months. TSH levels did not vary significantly during the course of therapy. TT (3)/TT (4) and FT (3)/FT (4) ratios increased significantly after six and twelve months of therapy and significantly decreased later, approaching pre-therapy values. The SDS of Growth Velocity (SDS-GV) increased remarkably during the first year of therapy and then decreased significantly during the second year, although it remained significantly higher than the pre-therapy values. TT (3) and TT (3)/TT (4) ratio displayed a significant correlation with SDS-GV at twelve months of therapy. In a multiple regression analysis with age, bone age, parental height, GH dose, TT (3,) TT (3)/TT (4), and the SDS of IGF-I, only the TT (3)/TT (4) ratio at twelve months of therapy (p < 0.001) was identified as a significant predictor of SDS-GV.
Conclusion:
Our data confirm that changes in thyroid function are present in GHD children during long-term hGH therapy. These changes probably resulted from the effect of hGH on the peripheral metabolism of thyroid hormones and appear to be transitory, disappearing during the second year of hGH treatment. We speculate on the functional significance of these changes, and in particular, on their role in catch-up growth after hGH therapy.
Related Concept Videos
01:18Functions of Thyroid Hormones
TH is indispensable for the normal development and maturation of the skeletal, muscular, and nervous systems during fetal and childhood growth. It facilitates bone mineral turnover and regulates protein synthesis in developing tissues, contributing significantly to overall growth and...
01:25Hyperthyroidism I: Introduction
01:24Graves Disease II: Pathophysiology
01:20Synthesis and Regulation of Thyroid Hormones
Upon reaching the thyroid gland, TSH stimulates the follicular cells' active uptake of iodide ions from the blood. The ions diffuse to the apical surface of the cells and are oxidized to iodine. The iodine is then...
01:27Hyperthyroidism II: Pathophysiology
01:17Hormones and Bone Tissue
Hormones That Influence Osteoblasts and/or Maintain the Matrix
Several hormones are necessary for controlling bone growth and maintaining the bone matrix. The pituitary gland secretes growth hormone (GH), which, as its name implies, controls bone growth. This happens in several ways: first, it triggers chondrocyte...