[Functional states of pituitary-ovary, adrenal and thyroid axes in women with polycystic ovarian syndrome].

OBJECTIVE

To assess the role of the functional states of pituitary-ovary, adrenal and thyroid axes in the pathophysiology of polycystic ovarian syndrome (PCOS).

METHODS

The stimulation tests of above-mentioned three endocrine axes by luteinizing hormone releasing hormone (LRH, 100 micrograms), adrenocorticotrophin (ACTH, 250 micrograms) and thyroid releasing hormoune (TRH, 500 micrograms), respectively, were performed in each subjects of two PCOS groups [luteinizing hormone/follicle stimulating hormone (LH/FSH) > or = 3, Group 1, n = 15; LH/FSH < 3, Group 2, n = 15] and the control (n = 20). Endocrine indices of corresponding target glands were evaluated by radioimmunoassay (RIA).

RESULTS

After LRH administration, the amplitude of LH responses in three groups were as follows: Group 1 > Group 2 > control while mean testosterone levels were elevated to a similar extent in two PCOS groups and remained unchanged in the control. Following ACTH stimulation, PCOS subjects, especially of Group 2 with obvious insulin resistance, showed higher responses of cortisol, dehydroepiandrosterone sulfate and testosterone as compared with the controls. However, during TRH testing, exaggerated thyroid-stimulating hormone and prolactin responses in two PCOS groups and blunted free thyroxine response at two hour point in Group 1 were observed, as compared with the control.

CONCLUSION

It appears that ovarian androgen excess in women with PCOS is mainly LH-dependent in Group 1 and insulin-dependent in Group 2. Enhanced adrenal activity may contribute to both hyperandrogenism and insulin resistance in this syndrome, and subclinical hypothyroidism may exist in affected subjects, especially of Group 1.