Gender and age influence the relationship between serum GH and IGF-I in patients with acromegaly.

2.50
Hdl Handle:
http://hdl.handle.net/10541/79997
Title:
Gender and age influence the relationship between serum GH and IGF-I in patients with acromegaly.
Authors:
Parkinson, Craig; Renehan, Andrew G; Ryder, W David J; O'Dwyer, Sarah T; Shalet, Stephen M; Trainer, Peter J
Abstract:
BACKGROUND: In patients with acromegaly serum IGF-I is increasingly used as a marker of disease activity. As a result, the relationship between serum GH and IGF-I is of profound interest. Healthy females secrete three times more GH than males but have broadly similar serum IGF-I levels, and women with GH deficiency require 30-50% more exogenous GH to maintain the same serum IGF-I as GH-deficient men. In a selected cohort of patients with active acromegaly, studied off medical therapy using a single fasting serum GH and IGF-I measurement, we have reported previously that, for a given GH level, women have significantly lower circulating IGF-I. OBJECTIVE: To evaluate the influence of age and gender on the relationship between serum GH and IGF-I in an unselected cohort of patients with acromegaly independent of disease control and medical therapy. METHODS: Sixty (34 male) unselected patients with acromegaly (median age 51 years (range 24-81 years) attending a colonoscopy screening programme were studied. Forty-five had previously received pituitary radiotherapy. Patients had varying degrees of disease control and received medical therapy where appropriate. Mean serum GH was calculated from an eight-point day profile (n = 45) and values obtained during a 75-g oral glucose tolerance test (n = 15). Serum IGF-I, IGFBP-3 and acid-labile subunit were measured and the dependency of these factors on covariates such as log10 mean serum GH, sex, age and prior radiotherapy was assessed using regression techniques. RESULTS: The median calculated GH value was 4.7 mU/l (range 1-104). A significant linear association was observed between serum IGF-I and log10 mean serum GH for the cohort (R = 0.5, P < 0.0001). After simultaneous adjustment of the above covariates a significant difference in the relationship between mean serum GH and IGF-I was observed for males and females. On average, women had serum IGF-I levels 11.44 nmol/l lower than men with the same mean serum GH (P = 0.03, 95% CI 1.33-21.4 nmol/l). Age significantly influenced the relationship and for a given serum GH, IGF-I was estimated to fall by 0.37 nmol/l per year (P = 0.04, 95% CI 0.015-0.72). CONCLUSIONS: In keeping with previous observations of relative GH resistance in normal and GH-deficient females we have observed lower serum IGF-I levels for equivalent mean serum GH levels in females patients with acromegaly. This gender-dependent difference is independent of disease activity and the use of concomitant medical therapy. Additionally, we have demonstrated that for a given serum GH level, age significantly influences IGF-I concentrations in patients with acromegaly. These data have important implications for the use of serum IGF-I and GH as markers of disease activity in acromegaly.
Affiliation:
Department of Endocrinology, Christie Hospital, Manchester, UK.
Citation:
Gender and age influence the relationship between serum GH and IGF-I in patients with acromegaly. 2002, 57 (1):59-64 Clin. Endocrinol. (Oxf)
Journal:
Clinical Endocrinology
Issue Date:
Jul-2002
URI:
http://hdl.handle.net/10541/79997
DOI:
10.1046/j.1365-2265.2002.01560.x
PubMed ID:
12100070
Type:
Article
Language:
en
ISSN:
0300-0664
Appears in Collections:
All Christie Publications

Full metadata record

DC FieldValue Language
dc.contributor.authorParkinson, Craig-
dc.contributor.authorRenehan, Andrew G-
dc.contributor.authorRyder, W David J-
dc.contributor.authorO'Dwyer, Sarah T-
dc.contributor.authorShalet, Stephen M-
dc.contributor.authorTrainer, Peter J-
dc.date.accessioned2009-09-07T10:48:53Z-
dc.date.available2009-09-07T10:48:53Z-
dc.date.issued2002-07-
dc.identifier.citationGender and age influence the relationship between serum GH and IGF-I in patients with acromegaly. 2002, 57 (1):59-64 Clin. Endocrinol. (Oxf)en
dc.identifier.issn0300-0664-
dc.identifier.pmid12100070-
dc.identifier.doi10.1046/j.1365-2265.2002.01560.x-
dc.identifier.urihttp://hdl.handle.net/10541/79997-
dc.description.abstractBACKGROUND: In patients with acromegaly serum IGF-I is increasingly used as a marker of disease activity. As a result, the relationship between serum GH and IGF-I is of profound interest. Healthy females secrete three times more GH than males but have broadly similar serum IGF-I levels, and women with GH deficiency require 30-50% more exogenous GH to maintain the same serum IGF-I as GH-deficient men. In a selected cohort of patients with active acromegaly, studied off medical therapy using a single fasting serum GH and IGF-I measurement, we have reported previously that, for a given GH level, women have significantly lower circulating IGF-I. OBJECTIVE: To evaluate the influence of age and gender on the relationship between serum GH and IGF-I in an unselected cohort of patients with acromegaly independent of disease control and medical therapy. METHODS: Sixty (34 male) unselected patients with acromegaly (median age 51 years (range 24-81 years) attending a colonoscopy screening programme were studied. Forty-five had previously received pituitary radiotherapy. Patients had varying degrees of disease control and received medical therapy where appropriate. Mean serum GH was calculated from an eight-point day profile (n = 45) and values obtained during a 75-g oral glucose tolerance test (n = 15). Serum IGF-I, IGFBP-3 and acid-labile subunit were measured and the dependency of these factors on covariates such as log10 mean serum GH, sex, age and prior radiotherapy was assessed using regression techniques. RESULTS: The median calculated GH value was 4.7 mU/l (range 1-104). A significant linear association was observed between serum IGF-I and log10 mean serum GH for the cohort (R = 0.5, P < 0.0001). After simultaneous adjustment of the above covariates a significant difference in the relationship between mean serum GH and IGF-I was observed for males and females. On average, women had serum IGF-I levels 11.44 nmol/l lower than men with the same mean serum GH (P = 0.03, 95% CI 1.33-21.4 nmol/l). Age significantly influenced the relationship and for a given serum GH, IGF-I was estimated to fall by 0.37 nmol/l per year (P = 0.04, 95% CI 0.015-0.72). CONCLUSIONS: In keeping with previous observations of relative GH resistance in normal and GH-deficient females we have observed lower serum IGF-I levels for equivalent mean serum GH levels in females patients with acromegaly. This gender-dependent difference is independent of disease activity and the use of concomitant medical therapy. Additionally, we have demonstrated that for a given serum GH level, age significantly influences IGF-I concentrations in patients with acromegaly. These data have important implications for the use of serum IGF-I and GH as markers of disease activity in acromegaly.en
dc.language.isoenen
dc.subject.meshAcromegaly-
dc.subject.meshAdult-
dc.subject.meshAge Factors-
dc.subject.meshAged-
dc.subject.meshAged, 80 and over-
dc.subject.meshAging-
dc.subject.meshBiological Markers-
dc.subject.meshCase-Control Studies-
dc.subject.meshFemale-
dc.subject.meshGrowth Hormone-
dc.subject.meshHumans-
dc.subject.meshInsulin-Like Growth Factor I-
dc.subject.meshMale-
dc.subject.meshMiddle Aged-
dc.subject.meshRegression Analysis-
dc.subject.meshSex-
dc.subject.meshSex Factors-
dc.titleGender and age influence the relationship between serum GH and IGF-I in patients with acromegaly.en
dc.typeArticleen
dc.contributor.departmentDepartment of Endocrinology, Christie Hospital, Manchester, UK.en
dc.identifier.journalClinical Endocrinologyen
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