Increased serum inhibin B levels in postmenopausal women with altered thyroid function.
Hyper- and hypothyroidism have significant effects on the female reproductive system. However, little in the way of data is available on the relationship between ovarian paracrine control and thyroid function. This study was aimed at characterising the serum levels of inhibin B in relation to altered thyroid function. Serum inhibin B and FSH levels were measured in 91 women (51 regularly cycling and 40 postmenopausal). The mean serum concentration of inhibin B in euthyroid cycling women (0.025 +/- 0.018 microg/l) was similar to that observed in hyper- and hypothyroid patients (0.022 +/- 0.015 and 0.018 +/- 0.014 microg/l, respectively, p=ns). Inhibin B levels were obviously reduced (-72%) in euthyroid postmenopausal women. In contrast, in hyper- and hypothyroid postmenopausal women, inhibin B levels remained substantially at the premenopausal level. So far, serum inhibin B appeared to be significantly increased in both hyperthyroid patients (0.025 +/- 0.014 microg/l; p<0.0001) and in hypothyroid patients (0.016 +/- 0.006 microg/l; p=0.0006). Altered thyroid function did not affect FSH levels at fertile age. However, a significant decrease of FSH levels was observed in hyper- and hypothyroid (-52% and -43%, respectively) postmenopausal women. Nevertheless, these FSH levels remained in the postmenopausal range. These results indicate that an altered thyroid function affects serum inhibin B levels in postmenopausal women.
Viceconti
N
N
Department of Experimental Medicine and Pathology, University of Rome, 00161 Rome, Italy.
Luisi
S
S
Nardo
S
S
Gargano
L
L
Franchi
A
A
Sibilla
R
R
Canettieri
G
G
Petraglia
F
F
Centanni
M
M
D000328:Adult; D016022:Case-Control Studies; D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood; D006801:Humans; D006980:Hyperthyroidism / Q000503:physiopathology*; D007037:Hypothyroidism / Q000503:physiopathology*; D007265:Inhibins / Q000097:blood*; D008597:Menstrual Cycle / Q000097:blood; D008875:Middle Aged; D009994:Osmolar Concentration; D017698:Postmenopause / Q000097:blood*; D013960:Thyroid Function Tests; D013961:Thyroid Gland / Q000503:physiopathology*
C422364:inhibin B; D007265:Inhibins; D005640:Follicle Stimulating Hormone