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.
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.
Holl
R W
RW
Department of Pediatrics I, University of Ulm, FRG.
Kunze
D
D
Blum
W F
WF
Benz
R
R
Etzrodt
H
H
Heinze
E
E
D000328:Adult; D001120:Arginine / Q000494:pharmacology; D002352:Carrier Proteins / Q000097:blood; D005260:Female; D006130:Growth Disorders / Q000188:drug therapy / Q000209:etiology / Q000503:physiopathology; D013006:Growth Hormone / Q000097:blood / Q000172:deficiency / Q000378:metabolism*; D006801:Humans; D018969:Insulin-Like Growth Factor Binding Proteins; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D007335:Insulin-Like Growth Factor II / Q000378:metabolism; D008875:Middle Aged; D013002:Somatomedins / Q000378:metabolism*; D014424:Turner Syndrome / Q000097:blood / Q000150:complications / Q000503:physiopathology*
D002352:Carrier Proteins; D018969:Insulin-Like Growth Factor Binding Proteins; D013002:Somatomedins; D007334:Insulin-Like Growth Factor I; D007335:Insulin-Like Growth Factor II; D013006:Growth Hormone; D001120:Arginine; C051815:somatotropin-binding protein