Why t4 with hgh

Six patients were on oral L-thyroxine because of TSH deficiency. Before and after one month of hGH therapy 2U three times weekly , a single dose of T3 50 to ug was administered orally; serum levels of T3 and T4 were measured at 0, 4, 6, 12, 18 and 24 hours.

Both before and after hGH therapy, serum levels of T3 peaked at 4 hours and returned to normal by 24 hours. After hGH therapy, significantly higher levels of T3 were achieved at 0, 4, 6, 18 and 24 hours p values from 0. In contrast, following T3 ingestion, serum levels of T4 decreased and reached a nadir at 18 hours. The decrease in serum levels of T4 were of similar magnitude whether the patients were or were not receiving replacement therapy with L-thyroxine.

Therefore, these changes could not be explained by T3 induced suppression of thyroid gland. The decrease in serum levels of T4 was not influenced by hGH therapy. In conclusion, hGH causes an increase in the basal level of serum T3 and an augmentation of T3 levels following a loading dose of T3; mechanisms for these changes are not known.

The decrease in serum levels of T4 following a T3 load, although not altered by hGH, is of special interest. This effect seems to be due to changes in extrathyroidal metabolism of T4. Temple Univ. Christopher's Hospital for Children, Philadelphia. This is a preview of subscription content, access via your institution. Rent this article via DeepDyve. Oliner L. Effect of human growth hormone on thyroidal secretion, radiothyroxine turnover and transport in man. Sack J. Hypothyroidism after growth hormone therapy.

Pediatrics 52 : , Google Scholar. Porter B. Abnormal thyroxine metabolism in hyposomatotrophic dwarfism and inhibition of responsiveness to TRH during GH therapy. Pediatrics 51 : , Lippe B.

Reversible hypothyroidism in growth hormone-deficient children treated with human growth hormone. Sato T. Enhanced peripheral conversion of thyroxine to triiodothyronine during hGH therapy -in GH deficient children. Article Google Scholar. Rosenbloom A. Low dose single weekly -injections of growth hormone: response during first year of therapy of hypopituitarism. Pediatrics 66 : , Demura R. The effect of hGH on hypothalamic-pituitary-thyroid function in patients with pituitary dwarfism.

Acta Endocrinol. CAS Google Scholar. Rezvani I. Action of human growth hormone hGH on extrathyroidal conversion of thyroxine T4 to triiodothyronine T3 in children with hypopituitarism. Stahnke N. Replacement therapy in hypothalamus-pituitary insufficiency: management in the adolescent. PubMed Article Google Scholar. Pirazzoli P. Growth and thyroid function in children treated with growth hormone. Sacco V. Effetti del trattamento con GH-biosintetico sulla funzione tiroidea in soggetti con deficit isolato di GH.

Minerva Endocrinol. Cohen et al 30 also found that the FT3 1 month after treatment in GHD patients was increased and the difference was statistically significant, but 6 months after treatment the difference was not statistically significant. Some investigators have suggested that GH promoted the secretion of somatostatin, which further inhibited the secretion of TSH and led to changes in thyroid hormone release 32 — The present study found that thyroid hormone levels in the two groups changed, but they changed more significantly in the high-dose group.

High doses of rhGH had a greater impact on thyroid function, and the possibility of adverse reactions cannot be excluded. In this study, we examined the effects of different doses of rhGH on children with GHD, as well as the changes in the thyroid and glycometabolism. Previously, the high dose of rhGH was thought to have a greater effect on linear growth catch-up and treatment.

At the same time, however, high doses of rhGH also increased the incidence of abnormalities in glucose metabolism and thyroid. Since the present study was performed over a relatively short period of time, obvious signs of high blood sugar syndrome and hyperglycemic hyperosmolar syndrome did not manifest in patients. Thus, we hypothesize that high doses of rhGH may have a greater impact on glucose metabolism and thyroid functions and cause a higher risk of function changes.

Thus, in future studies attention should be paid to the indicators of glucose metabolism and thyroid function. Oxf Med Case Rep. View Article : Google Scholar.

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GH Research Society. Horm Res. Apr 29— Horm Res Paediatr. Mar 25— Clin Endocrinol Oxf. Mar 21— J Hypertens. J Clin Res Pediatr Endocrinol. Feb 14— J Pediatr. Sohmiya M and Kato Y: Effect long-term treatment with recombinant human growth hormone on erythropoietin secretion in an anemic patient with panhypopituitarism. J Endocrinol Invest. Endocr Rev. May Volume 11 Issue 5. Sign up for eToc alerts. You can change your cookie settings at any time by following the instructions in our Cookie Policy.

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