The somatotropin-somatomedin axis in adult patients with Turner syndrome: measurement of stimulated GH, GH-BP, IGF-I, IGF-II and IGFBP-3 in 25 patients

• Published in: Hormone research Vol. 39; no. 1-2; p. 30
• Main Authors: Holl, R W, Kunze, D, Blum, W F, Benz, R, Etzrodt, H, Heinze, E
• Format: Journal Article
• Language: English
• Published: Switzerland 01.01.1993
• Subjects: Adult; Arginine - pharmacology; Carrier Proteins - blood; Female; Growth Disorders - drug therapy; Growth Disorders - etiology; Growth Disorders - physiopathology; Growth Hormone - blood; Growth Hormone - deficiency; Growth Hormone - secretion; Humans; Insulin-Like Growth Factor Binding Proteins; Insulin-Like Growth Factor I - metabolism; Insulin-Like Growth Factor II - metabolism; Middle Aged; Somatomedins - secretion; Turner Syndrome - blood; Turner Syndrome - complications; Turner Syndrome - physiopathology
• ISSN: 0301-0163
• DOI: 10.1159/000182691

So far, few studies have addressed the regulation of GH and GH-dependent growth factors in adult patients with Turner syndrome. We therefore studied a group of 25 genetically proven patients with Turner syndrome (age 20-50 years) and 10 control women (25-48 years). Turner patients were significantly shorter (148.7 +/- 1.1 cm vs. 169.1 +/- 2.3 cm; mean +/- SE; p < 0.0001) and more overweight [body mass index (BMI)] 25.6 +/- 1.3 vs. 21.4 +/- 0.6 in controls; p < 0.01). No significant differences were present when the integrated GH response to stimulation with arginine and the serum levels of GH-binding protein (GH-BP), IGF-I, IGF-II and binding protein 3 for IGFs (IGFBP-3) were compared between the two groups. However, more detailed analysis revealed significant abnormalities of the somatotropic axis in Turner patients. Pituitary GH secretion was negatively and serum GH-BP positively related to the degree of overweight in normal patients. In Turner patients, no such relationship was present, while IGF-II significantly increased with BMI. IGFBP-3 was positively related to adult height in normal women but not in Turner patients. While serum testosterone values did not affect any of the somatotropic parameters measured, there was a previously unreported, inverse relation between serum estradiol and GH-BP in controls but not in Turner patients. While adult patients with Turner syndrome do not display endocrine features of GH insufficiency, a detailed analysis reveals several abnormalities of the interrelation between anthropometric parameters, sex steroids and the pituitary-somatomedin axis.