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Effects of growth hormone treatment on serum levels of insulin‐like growth factors (IGFs) and IGF binding proteins 1–4 in postmenopausal women
Author(s) -
Kassem M.,
Brixen K.,
Mosekilde L.,
Blum W. F.,
Flyvbjerg A.
Publication year - 1998
Publication title -
clinical endocrinology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.055
H-Index - 147
eISSN - 1365-2265
pISSN - 0300-0664
DOI - 10.1046/j.1365-2265.1998.00606.x
Subject(s) - endocrinology , medicine , insulin like growth factor binding protein , igfbp3 , growth factor , insulin like growth factor , insulin , radioimmunoassay , somatomedin , hormone , insulin like growth factor 2 , growth hormone , biology , receptor
BACKGROUND AND OBJECTIVE Insulin‐like growth factor binding proteins (IGFBPs) modulate the actions and bioavailability of insulin‐like growth factors (IGFs), however, their regulation in vivo is incompletely understood. In this study we investigated the effects of different doses of growth hormone (GH) on circulating levels of IGFs and IGFBPs. DESIGN The study was double‐blind and placebo‐controlled. Patients were treated with either GH in doses of 0.05, 0.10, or 0.20 IU/kg/day of placebo for one week. PATIENTS Forty post‐menopausal women aged 52–73 years with low bone mass. MEASUREMENTS Serum IGF‐I and IGF‐II were measured by RIA while IGFBP‐1–3 were measured by Western ligand blot (WLB) and compared with determinations by specific immunoassays. IGFBP‐4 was measured by WLB alone. RESULTS Both IGF‐I ( P < 0.001) and IGF‐II ( P < 0.01) increased significantly during GH treatment. Additionally, IGFBP‐1 ( P < 0.001) and IGFBP‐2 ( P < 0.001) decreased significantly while IGFBP‐3 ( P < 0.001) and IGFBP‐4 ( P < 0.05) increased all in a dose‐dependent manner. Stepwise (backwards) multiple regression analyses showed that the changes in IGF‐I and IGF‐II, and age correlated with the change in serum IGFBP‐1. Both GH‐dosage, the increase in IGF‐II, and body mass index correlated with the decrease in IGFBP‐2. Furthermore, the increase in serum IGF‐I, IGF‐II, and triiodothyronine correlated with the increase in IGFBP‐3. Moreover, GH‐dosage correlated with the increase in serum IGFBP‐4. CONCLUSION GH significantly increased serum IGF‐I, IGF‐II, IGFBP‐3, and IGFBP‐4 and decreased serum IGFBP‐1 and IGFBP‐2 in post‐menopausal women.