Gender and age influence the relationship between serum GH and IGF-I in patients with acromegaly.
Renehan, Andrew G
Ryder, W David J
O'Dwyer, Sarah T
Shalet, Stephen M
Trainer, Peter J
AffiliationDepartment of Endocrinology, Christie Hospital, Manchester, UK.
MetadataShow full item record
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.
CitationGender and age influence the relationship between serum GH and IGF-I in patients with acromegaly. 2002, 57 (1):59-64 Clin. Endocrinol. (Oxf)
- The relationship between serum GH and serum IGF-I in acromegaly is gender-specific.
- Authors: Parkinson C, Ryder WD, Trainer PJ, Sensus Acromegaly Study Group.
- Issue date: 2001 Nov
- Relationships between insulin-like growth factor-1 levels and growth hormone concentrations during diurnal profiles and following oral glucose in acromegaly.
- Authors: Dobrashian RD, O'Halloran DJ, Hunt A, Beardwell CG, Shalet SM
- Issue date: 1993 Jun
- Diagnostic value of the acid-labile subunit in acromegaly: evaluation in comparison with insulin-like growth factor (IGF) I, and IGF-binding protein-1, -2, and -3.
- Authors: Arosio M, Garrone S, Bruzzi P, Faglia G, Minuto F, Barreca A
- Issue date: 2001 Mar
- Diagnostic value of serum IGF-I and IGFBP-3 in growth hormone disorders in adults.
- Authors: Kim HJ, Kwon SH, Kim SW, Park DJ, Shin CS, Park KS, Kim SY, Cho BY, Lee HK
- Issue date: 2001
- The effect of pegvisomant-induced serum IGF-I normalization on serum leptin levels in patients with acromegaly.
- Authors: Parkinson C, Whatmore AJ, Yates AP, Drake WM, Brabant G, Clayton PE, Trainer PJ
- Issue date: 2003 Aug