The Journal of clinical endocrinology and metabolism
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J. Clin. Endocrinol. Metab. · Nov 2000
Clinical TrialPolycystic ovarian syndrome: evidence that flutamide restores sensitivity of the gonadotropin-releasing hormone pulse generator to inhibition by estradiol and progesterone.
Polycystic ovarian syndrome (PCOS) is a complex disorder with multiple abnormalities, including hyperandrogenism, ovulatory dysfunction, and altered gonadotropin secretion. The majority of patients have elevated LH levels in plasma and a persistent rapid frequency of LH (GnRH) pulse secretion, the mechanisms of which are unclear. Earlier work has suggested that the sensitivity of the GnRH pulse generator to inhibition by ovarian steroids is impaired. ⋯ After the addition of E2 and P for 7 days, both PCOS patients and normal controls had similar reductions in LH pulse frequency (4.0+/-0.7 and 5.8+/-0.7 pulses/12 h, respectively). This contrasts with our earlier results in the absence of flutamide, where a plasma P level of less than 10 ng/mL had minimal effects on LH pulse frequency in women with PCOS, but was effective in controls. These results suggest that although the elevated LH pulse frequency in PCOS may in part reflect impaired sensitivity to E2 and P, continuing actions of hyperandrogenemia are important for sustaining the abnormal hypothalamic sensitivity to feedback inhibition by ovarian steroids.
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J. Clin. Endocrinol. Metab. · Oct 2000
Comparative Study Clinical TrialA comparison between the 1-microg adrenocorticotropin (ACTH) test, the short ACTH (250 microg) test, and the insulin tolerance test in the assessment of hypothalamo-pituitary-adrenal axis immediately after pituitary surgery.
The short ACTH stimulation test is an easy, reliable, and extensively used test in the assessment of the hypothalamo-pituitary-adrenal (HPA) axis. However, its use immediately after pituitary surgery is a matter of debate. The insulin tolerance test (ITT) is the gold standard in the evaluation of the HPA axis, but it is not always without side effects and may be unpleasant early after pituitary surgery. ⋯ In the early postoperative period of pituitary surgery, the 1-microg ACTH test results are more concordant than the 250-microg ACTH test in comparison with the ITT. Our results also indicate that HPA axis dysfunction shown by ACTH stimulation tests and the ITT in early postoperative period may be normalized 1-3 months after surgery. For this reason, we think that dynamic tests including the ITT may not be useful early after pituitary surgery.
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J. Clin. Endocrinol. Metab. · Oct 2000
Comparative Study Clinical TrialSexual dimorphism in the influence of advanced aging on adrenal hormone levels: the Rancho Bernardo Study.
In recent years, adrenal function and aging has been the subject of intense interest. This cross-sectional study examines age and gender differences in plasma levels of cortisol, dehydroepiandrosterone (DHEA), DHEA-sulfate (DHEAS), and the molar ratio of cortisol/DHEAS in 50-89-yr-old community-dwelling adults. Plasma hormone levels were assayed in samples obtained between 0730 h and 1100 h from 857 men and 735 nonestrogen-using, postmenopausal women. ⋯ The age-related decline in adrenal androgens persists into advanced age for both men and women, but exhibits a sexually dimorphic pattern. In contrast, cortisol levels in men and women show a parallel, linear increase with aging. These findings may have important implications for a host of age-related processes that exhibit gender differences, including brain function, bone metabolism, and cardiovascular disease.
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J. Clin. Endocrinol. Metab. · Sep 2000
Randomized Controlled Trial Clinical TrialEndocrine and metabolic effects of metformin versus ethinyl estradiol-cyproterone acetate in obese women with polycystic ovary syndrome: a randomized study.
Metformin, a biguanide antihyperglycemic drug, has been shown to improve ovarian function and glucose metabolism in women with polycystic ovary syndrome (PCOS), but results concerning its effects on insulin sensitivity are controversial. Oral contraceptive pills are commonly used in the treatment of PCOS; but, like metformin, their influence on insulin sensitivity is not well known. We randomized 32 obese (body mass index > 27 kg/m2) women with PCOS, either to metformin (500 mg x 2 daily for 3 months, then 1,000 mg x 2 daily for 3 months) or to ethinyl estradiol (35 microg)-cyproterone acetate (2 mg) oral contraceptive pills (Diane Nova) for 6 months. ⋯ Diane Nova significantly decreased serum testosterone and increased serum sex hormone-binding globulin concentrations and glucose area under the curve during oral glucose tolerance test. It is concluded that metformin, probably by way of its effect on adipose tissue, leads to reduction of hyperinsulinemia and concomitant improvement in the menstrual pattern; and therefore, it offers a useful alternative treatment for obese, anovulatory women with PCOS. Despite slight worsening of glucose tolerance, Diane Nova is an efficient treatment for women with hyperandrogenism and hirsutism.