Relationships between insulin-like growth factor-1 levels and growth hormone concentrations during diurnal profiles and following oral glucose in acromegaly.

2.50
Hdl Handle:
http://hdl.handle.net/10541/99799
Title:
Relationships between insulin-like growth factor-1 levels and growth hormone concentrations during diurnal profiles and following oral glucose in acromegaly.
Authors:
Dobrashian, R D; O'Halloran, Domhnall J; Hunt, A; Beardwell, Colin G; Shalet, Stephen M
Abstract:
OBJECTIVE: The aim of this study was to refine the biochemical definition of disease activity in acromegaly by comparing serum growth hormone (GH) measurements during a 10-hour day profile with serum GH values during an oral glucose tolerance test. DESIGN: Using plasma insulin-like growth factor-1 (IGF-1) levels as a measure of disease activity, serum GH data from a day profile and from an oral glucose tolerance test were compared. PATIENTS: Thirty-five acromegalic patients were studied, 13 of whom had serum GH measured during a day profile and 22 during an oral glucose tolerance test. In addition, basal plasma IGF-1 levels were estimated in all acromegalic patients, and in 24 normal subjects. MEASUREMENTS: Following acid-ethanol extraction of the plasma samples, IGF-1 levels were measured by radioimmunoassay using a polyclonal antibody. In a day profile, six to eight blood samples for serum GH estimation were taken at hourly intervals during the day; during an oral glucose tolerance test samples for serum GH estimation were taken in the fasting state and every 30 minutes for 2 hours and measured by a two-site IRMA for GH. RESULTS: Ninety-four per cent of acromegalic patients with raised plasma IGF-1 levels had serum GH concentrations > 10 mU/l whilst 98% of acromegalic patients with plasma IGF-1 levels in the normal range had serum GH concentrations < 6 mU/l. A highly significant positive correlation was found between the mean serum GH concentrations (r = 0.67), the minimum serum GH concentration (r = 0.65) and the area under the GH curve (r = 0.66) estimated during an oral glucose tolerance test and plasma IGF-1 concentrations. The relations between identical indices of serum GH concentration measured during a day profile and plasma IGF-1 levels, although significant, show a less powerful correlation. The relation between serum GH and plasma IGF-1 levels describes a curvilinear model, plasma IGF-1 levels exhibiting a plateau at serum GH concentrations > 40 mU/l but maintaining a linear relationship with serum GH levels < 20 mU/l. CONCLUSIONS: A highly significant correlation exists between plasma IGF-1 levels and various parameters of serum GH levels in acromegalic patients. Hormonal assessment of disease activity in acromegaly is more accurately reflected by the serum GH concentration during an oral glucose tolerance test rather than by the serum GH level during a day profile. Normalization of plasma IGF-1 levels is rarely achieved unless the mean serum GH level is reduced to < 6 mU/l.
Affiliation:
Department of Endocrinology, Christie Hospital, Manchester, UK.
Citation:
Relationships between insulin-like growth factor-1 levels and growth hormone concentrations during diurnal profiles and following oral glucose in acromegaly. 1993, 38 (6):589-93 Clin. Endocrinol. (Oxf)
Journal:
Clinical Endocrinology
Issue Date:
Jun-1993
URI:
http://hdl.handle.net/10541/99799
DOI:
10.1111/j.1365-2265.1993.tb02139.x
PubMed ID:
8334745
Type:
Article
Language:
en
ISSN:
0300-0664
Appears in Collections:
All Christie Publications

Full metadata record

DC FieldValue Language
dc.contributor.authorDobrashian, R Den
dc.contributor.authorO'Halloran, Domhnall Jen
dc.contributor.authorHunt, Aen
dc.contributor.authorBeardwell, Colin Gen
dc.contributor.authorShalet, Stephen Men
dc.date.accessioned2010-05-25T11:06:27Z-
dc.date.available2010-05-25T11:06:27Z-
dc.date.issued1993-06-
dc.identifier.citationRelationships between insulin-like growth factor-1 levels and growth hormone concentrations during diurnal profiles and following oral glucose in acromegaly. 1993, 38 (6):589-93 Clin. Endocrinol. (Oxf)en
dc.identifier.issn0300-0664-
dc.identifier.pmid8334745-
dc.identifier.doi10.1111/j.1365-2265.1993.tb02139.x-
dc.identifier.urihttp://hdl.handle.net/10541/99799-
dc.description.abstractOBJECTIVE: The aim of this study was to refine the biochemical definition of disease activity in acromegaly by comparing serum growth hormone (GH) measurements during a 10-hour day profile with serum GH values during an oral glucose tolerance test. DESIGN: Using plasma insulin-like growth factor-1 (IGF-1) levels as a measure of disease activity, serum GH data from a day profile and from an oral glucose tolerance test were compared. PATIENTS: Thirty-five acromegalic patients were studied, 13 of whom had serum GH measured during a day profile and 22 during an oral glucose tolerance test. In addition, basal plasma IGF-1 levels were estimated in all acromegalic patients, and in 24 normal subjects. MEASUREMENTS: Following acid-ethanol extraction of the plasma samples, IGF-1 levels were measured by radioimmunoassay using a polyclonal antibody. In a day profile, six to eight blood samples for serum GH estimation were taken at hourly intervals during the day; during an oral glucose tolerance test samples for serum GH estimation were taken in the fasting state and every 30 minutes for 2 hours and measured by a two-site IRMA for GH. RESULTS: Ninety-four per cent of acromegalic patients with raised plasma IGF-1 levels had serum GH concentrations > 10 mU/l whilst 98% of acromegalic patients with plasma IGF-1 levels in the normal range had serum GH concentrations < 6 mU/l. A highly significant positive correlation was found between the mean serum GH concentrations (r = 0.67), the minimum serum GH concentration (r = 0.65) and the area under the GH curve (r = 0.66) estimated during an oral glucose tolerance test and plasma IGF-1 concentrations. The relations between identical indices of serum GH concentration measured during a day profile and plasma IGF-1 levels, although significant, show a less powerful correlation. The relation between serum GH and plasma IGF-1 levels describes a curvilinear model, plasma IGF-1 levels exhibiting a plateau at serum GH concentrations > 40 mU/l but maintaining a linear relationship with serum GH levels < 20 mU/l. CONCLUSIONS: A highly significant correlation exists between plasma IGF-1 levels and various parameters of serum GH levels in acromegalic patients. Hormonal assessment of disease activity in acromegaly is more accurately reflected by the serum GH concentration during an oral glucose tolerance test rather than by the serum GH level during a day profile. Normalization of plasma IGF-1 levels is rarely achieved unless the mean serum GH level is reduced to < 6 mU/l.en
dc.language.isoenen
dc.subject.meshAcromegaly-
dc.subject.meshAdult-
dc.subject.meshAged-
dc.subject.meshAged, 80 and over-
dc.subject.meshCircadian Rhythm-
dc.subject.meshFemale-
dc.subject.meshGlucose-
dc.subject.meshGlucose Tolerance Test-
dc.subject.meshGrowth Hormone-
dc.subject.meshHumans-
dc.subject.meshInsulin-Like Growth Factor I-
dc.subject.meshMale-
dc.subject.meshMiddle Aged-
dc.titleRelationships between insulin-like growth factor-1 levels and growth hormone concentrations during diurnal profiles and following oral glucose in acromegaly.en
dc.typeArticleen
dc.contributor.departmentDepartment of Endocrinology, Christie Hospital, Manchester, UK.en
dc.identifier.journalClinical Endocrinologyen
All Items in Christie are protected by copyright, with all rights reserved, unless otherwise indicated.