Endogenous estradiol may influence IGF-I levels in acromegalic women treated with pegvisomant.
We present the case of a 46-year-old woman with acromegaly currently being treated with the growth hormone (GH) receptor antagonist pegvisomant showing strongly fluctuating IGF-I levels. We prospectively measured estradiol, IGF-I, IGF-I binding protein, acid labile subunit, basal endogenous GH, binding protein and pegvisomant levels for 6 months every week. Estradiol levels showed a strongly negative correlation with IGF-I (r = -0.733, P < 0.001), and less so with ALS (r = -0.433, P < 0.05) and IGFBP3 (r = -0.590, P < 0.01). Estradiol was not significantly correlated with endogenous GH or pegvisomant levels. Likewise, IGF-I did not correlate with endogenous GH or pegvisomant levels. In our patient, endogenous estradiol levels have a significant influence on IGF-I levels. When female acromegalic patients on permanent pegvisomant treatment show fluctuating IGF-I levels, estradiol levels should be taken into consideration.
Roemmler
J
J
Endocrinology, Medizinische Klinik-Innenstadt, University of Munich, Ziemssenstr. 1, 80336, München, Germany. josefine.roemmler@med.uni-muenchen.de
Bidlingmaier
M
M
Schopohl
J
J
D000172:Acromegaly / Q000097:blood / Q000188:drug therapy*; D004958:Estradiol / Q000097:blood*; D005260:Female; D019382:Human Growth Hormone / Q000031:analogs & derivatives* / Q000494:pharmacology / Q000627:therapeutic use; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000032:analysis*; D008875:Middle Aged; D011986:Receptors, Somatotropin / Q000037:antagonists & inhibitors
D011986:Receptors, Somatotropin; D019382:Human Growth Hormone; D004958:Estradiol; D007334:Insulin-Like Growth Factor I; C406545:pegvisomant