Modification of serum IGF-I, IGFBPs and SHBG levels by different HRT regimens.
During the menopause, levels of SHBG, IGF-I and IGFBPs are significantly modified by the use of different HRT regimens.


OBJECTIVE
The aim of this study is to evaluate the influence of three different HRT regimens on serum levels of SHBG, IGF-I, IGFBP-1 and IGFBP-3 in postmenopausal women.


METHODS
41 postmenopausal women requesting HRT were enrolled in the study. Subjects were divided in three groups according to the therapy assigned; Group A: estradiol 2 mg/day+cyproterone acetate 1 mg/day in a cyclic sequential regimen; Group B: estradiol hemihydrate 2 mg/day plus norethisterone acetate (NETA) 1 mg/day in a continuous combined regimen; Group C: estradiol hemihydrate 1 mg/day plus NETA 0.5 mg/day in a continuous combined regimen. Blood samples were drawn before the start of hormonal treatment and after 6 months of HRT. Levels of SHBG, IGF-I, IGFBP-1 and IGFBP-3 in the serum were measured by means of a specific immunoassay.


RESULTS
In group A, a significant increase of SHBG, no change of IGFBPs and a significant decrease of IGF-I were observed; in group B and in group C, no significant variations for any of the parameters were recorded.


CONCLUSIONS
The association of cyproterone acetate to oral estradiol determines a significant reduction of IGF-I levels and an increase of SHBG; nevertheless, it does not seem to influence the serum levels of the IGF-I binding proteins. The treatment with oral continuous combined estrogens plus androgenic progestins, at low doses, produces minor, not significant, changes in the circulating levels of IGF-I, SHBG and IGFBPs.
Biglia
Nicoletta
N
Academic Department of Gynaecological Oncology, Institute for Cancer Research and Treatment of Candiolo, University of Turin, Mauriziano Umberto 1st Hospital, Turin, Italy. nbiglia@mauriziano.it
Ambroggio
Simona
S
Ponzone
Riccardo
R
Sgro
Luca
L
Ujcic
Ester
E
Dato
Fabrizia Actis
FA
Sismondi
Piero
P
D000328:Adult; D001798:Blood Proteins / Q000187:drug effects*; D003534:Cyproterone / Q000008:administration & dosage; D004334:Drug Administration Schedule; D004958:Estradiol / Q000008:administration & dosage; D015914:Estrogen Replacement Therapy; D005260:Female; D006801:Humans; D018970:Insulin-Like Growth Factor Binding Protein 1 / Q000097:blood / Q000187:drug effects; D018971:Insulin-Like Growth Factor Binding Protein 2 / Q000097:blood / Q000187:drug effects; D007334:Insulin-Like Growth Factor I / Q000187:drug effects; D008875:Middle Aged; D009640:Norethindrone / Q000008:administration & dosage / Q000031:analogs & derivatives*; D000077563:Norethindrone Acetate; D017698:Postmenopause; D012738:Sex Hormone-Binding Globulin / Q000187:drug effects
D001798:Blood Proteins; D018970:Insulin-Like Growth Factor Binding Protein 1; D018971:Insulin-Like Growth Factor Binding Protein 2; D012738:Sex Hormone-Binding Globulin; D004958:Estradiol; D007334:Insulin-Like Growth Factor I; D000077563:Norethindrone Acetate; D003534:Cyproterone; D009640:Norethindrone