The effect of four weeks of supraphysiological growth hormone administration on the insulin-like growth factor axis in women and men

Dall, R. and Longobardi, S. and Ehrnborg, C. and Keay, N. and Rosen, T. and Jorgensen, J.O.L. and Cuneo, R.C. and Boroujerdi, M.A. and Cittadini, A. and Napoli, R. and Christiansen, J.S. and Bengtsson, B.A. and Sacca, L. and Baxter, R.C. and Basset, E.E. and Sonksen, P.H. (2000) The effect of four weeks of supraphysiological growth hormone administration on the insulin-like growth factor axis in women and men. Journal of Clinical Endocrinology and Metabolism, 85 (11). pp. 4193-4200. ISSN 0021-972X. (The full text of this publication is not available from this repository)

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Official URL
http://dx.doi.org/10.1210/jc.85.11.4193

Abstract

Measurements of serum insulin-like growth factor I (IGF-I) and related markers are routinely used in the diagnosis and treatment of GH deficiency and excess. The validity of these markers for assessment of exogenous GH exposure in healthy adults is, however, unknown. We therefore conducted a double blind, placebo-controlled GH treatment trial in 99 healthy subjects [49 women and 50 men; mean +/- SE age, 25.6 +/- 0.6 (women)/25.7 +/- 0.6 yr (men)]. Blood was collected weekly during a 4-week treatment period (days 1-28), and the subjects were subsequently followed for additional 8 weeks (days 29-84). The treatment arms included: I) 0.1 IU/kg.day GH (n = 30; GK 0.1), II) 0.2 IU/kg.day GH (n = 29; GH 0.2), and III) placebo (n = 40). At baseline no gender-specific differences existed, except that the acidlabile subunit (ALS) levels were higher in females. Serum insulin-like growth factor I (IGF-I) levels in males receiving GH increased significantly through day 42 with no significant difference between the 2 doses. The absolute IGF-I response was significantly lower in females, and there was a clear dose-response relationship. ALS levels in males increased through day 30 (P < 0.001). In females ALS levels were only modestly increased on day 28 compared with those in the placebo group (P < 0.02). IGF-binding protein-3 (IGFBP-3) levels in males increased significantly in the GH 0.1 and the GH 0.2 groups on day 30 (P < 0.03), whereas no solid IGFBP-3 increase was detected in females. IGFBP-2 levels decreased insignificantly during GH exposure in both genders. A gender-specific upper normal range for each analyte was arbitrarily defined as 4 sn above the mean level at baseline. On the basis of IGF-I levels alone, GH exposure in the GH 0.2 group was detected in 86% of the males and in 50% of the females on day 21. On day 42 GK exposure was only weakly detectable in males and was not detectable in females. We conclude that 1) males are significantly more responsive than females to exogenous GH; 2) the increase in IGF-I is more robust compared with those in IGFBP-3 and ALS; 3) IGFBP-2 changes very little during GH treatment; and 4) among IGF related substances, IGF-I is the most specific marker of supraphysiological GH exposure.

Item Type: Article
Subjects: Q Science > Q Science (General)
Divisions: Faculties > Science Technology and Medical Studies > School of Biosciences
Depositing User: P. Ogbuji
Date Deposited: 28 Mar 2009 22:53
Last Modified: 28 Mar 2009 22:53
Resource URI: http://kar.kent.ac.uk/id/eprint/16354 (The current URI for this page, for reference purposes)
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