The evolution of radiation-induced growth hormone deficiency in adults is determined by the baseline growth hormone status.

2.50
Hdl Handle:
http://hdl.handle.net/10541/98399
Title:
The evolution of radiation-induced growth hormone deficiency in adults is determined by the baseline growth hormone status.
Authors:
Toogood, Andy; Ryder, W David J; Beardwell, Colin G; Shalet, Stephen M
Abstract:
OBJECTIVE: Recent studies of GH replacement have suggested several beneficial effects for GH deficient adults. It would therefore be helpful to predict the time of onset of GH deficiency after external pituitary irradiation. We have studied the evolution of GH deficiency with time in patients irradiated for pituitary adenomas and other hypothalamic pituitary tumours. DESIGN: Analysis of serial peak GH responses to insulin hypoglycaemia following external irradiation to the hypothalamic-pituitary axis using statistical models which allowed for age, sex, previous surgery and the pre-radiotherapy GH peak response. PATIENTS: Eighty-five non-acromegalic adults (48 male), 75 of whom had either a pituitary adenoma or a craniopharyngioma and 10 who had other tumours in the hypothalamic-pituitary region. All the patients had received a radiation dose between 37.5 and 45 Gy divided into 15 fractions given over 21 days. MEASUREMENTS: The GH responses to an insulin tolerance test (ITT) performed as part of the regular endocrine follow-up in patients who received irradiation to the hypothalamic-pituitary region. RESULTS: Three hundred and forty-five ITTs were performed over a period of 10 years following radiotherapy. There was a decline in the modelled mean peak GH response to an ITT over the first 5 years which then appeared to plateau. Using an extended model, women had higher GH peak responses than men and this difference was maintained throughout the ten-year period. The magnitude of the post-radiotherapy peak GH response at any given time was dependent on the baseline peak GH response, but the rate of the decrease was not affected (P = 0.66). To develop severe GH deficiency (peak GH response less than 5 mU/l) after radiotherapy it took patients with baseline GH peaks of 30, 20 and 10 mU/l approximately 4 years, 3 years and 1 year respectively. Those patients with a baseline GH peak of greater than 50 mU/l are unlikely to develop severe GH deficiency within the first 5 years following radiotherapy. CONCLUSION: These results provide an insight into the pattern of the decline in GH secretion following radiotherapy in patients with pituitary disease and the factors affecting it. This information will help the clinician predict the frequency and timing of GH deficiency in patients irradiated for pituitary disease and the potential need for GH replacement therapy.
Affiliation:
Department of Endocrinology, Christie Hospital, Withington, Manchester, UK.
Citation:
The evolution of radiation-induced growth hormone deficiency in adults is determined by the baseline growth hormone status. 1995, 43 (1):97-103 Clin. Endocrinol
Journal:
Clinical Endocrinology
Issue Date:
Jul-1995
URI:
http://hdl.handle.net/10541/98399
DOI:
10.1111/j.1365-2265.1995.tb01898.x
PubMed ID:
7641416
Type:
Article
Language:
en
ISSN:
0300-0664
Appears in Collections:
All Christie Publications

Full metadata record

DC FieldValue Language
dc.contributor.authorToogood, Andyen
dc.contributor.authorRyder, W David Jen
dc.contributor.authorBeardwell, Colin Gen
dc.contributor.authorShalet, Stephen Men
dc.date.accessioned2010-05-10T16:23:51Z-
dc.date.available2010-05-10T16:23:51Z-
dc.date.issued1995-07-
dc.identifier.citationThe evolution of radiation-induced growth hormone deficiency in adults is determined by the baseline growth hormone status. 1995, 43 (1):97-103 Clin. Endocrinolen
dc.identifier.issn0300-0664-
dc.identifier.pmid7641416-
dc.identifier.doi10.1111/j.1365-2265.1995.tb01898.x-
dc.identifier.urihttp://hdl.handle.net/10541/98399-
dc.description.abstractOBJECTIVE: Recent studies of GH replacement have suggested several beneficial effects for GH deficient adults. It would therefore be helpful to predict the time of onset of GH deficiency after external pituitary irradiation. We have studied the evolution of GH deficiency with time in patients irradiated for pituitary adenomas and other hypothalamic pituitary tumours. DESIGN: Analysis of serial peak GH responses to insulin hypoglycaemia following external irradiation to the hypothalamic-pituitary axis using statistical models which allowed for age, sex, previous surgery and the pre-radiotherapy GH peak response. PATIENTS: Eighty-five non-acromegalic adults (48 male), 75 of whom had either a pituitary adenoma or a craniopharyngioma and 10 who had other tumours in the hypothalamic-pituitary region. All the patients had received a radiation dose between 37.5 and 45 Gy divided into 15 fractions given over 21 days. MEASUREMENTS: The GH responses to an insulin tolerance test (ITT) performed as part of the regular endocrine follow-up in patients who received irradiation to the hypothalamic-pituitary region. RESULTS: Three hundred and forty-five ITTs were performed over a period of 10 years following radiotherapy. There was a decline in the modelled mean peak GH response to an ITT over the first 5 years which then appeared to plateau. Using an extended model, women had higher GH peak responses than men and this difference was maintained throughout the ten-year period. The magnitude of the post-radiotherapy peak GH response at any given time was dependent on the baseline peak GH response, but the rate of the decrease was not affected (P = 0.66). To develop severe GH deficiency (peak GH response less than 5 mU/l) after radiotherapy it took patients with baseline GH peaks of 30, 20 and 10 mU/l approximately 4 years, 3 years and 1 year respectively. Those patients with a baseline GH peak of greater than 50 mU/l are unlikely to develop severe GH deficiency within the first 5 years following radiotherapy. CONCLUSION: These results provide an insight into the pattern of the decline in GH secretion following radiotherapy in patients with pituitary disease and the factors affecting it. This information will help the clinician predict the frequency and timing of GH deficiency in patients irradiated for pituitary disease and the potential need for GH replacement therapy.en
dc.language.isoenen
dc.subject.meshAdolescent-
dc.subject.meshAdult-
dc.subject.meshFemale-
dc.subject.meshGrowth Hormone-
dc.subject.meshHumans-
dc.subject.meshInsulin-
dc.subject.meshMale-
dc.subject.meshMiddle Aged-
dc.subject.meshPituitary Irradiation-
dc.subject.meshSex Factors-
dc.subject.meshTime Factors-
dc.titleThe evolution of radiation-induced growth hormone deficiency in adults is determined by the baseline growth hormone status.en
dc.typeArticleen
dc.contributor.departmentDepartment of Endocrinology, Christie Hospital, Withington, Manchester, UK.en
dc.identifier.journalClinical Endocrinologyen

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