Luteal phase dose-response relationships of the antiprogestin CDB-2914 in normally cycling women.

BACKGROUND: Progesterone receptor modulators have potential therapeutic use in progesterone-dependent conditions such as endometriosis, fibroids and induction of labour. The synthetic steroid CDB-2914 binds to the progesterone and glucocorticoid receptors. In animals it has antiprogestational activity at doses 50-fold less than those required for antiglucocorticoid effects. METHODS AND RESULTS: We evaluated the biological activity, blood levels and safety of CDB-2914 at escalating single doses, in 36 normally cycling women at mid-luteal phase. CDB-2914 at doses of 1-100 mg did not change luteal phase length, but after 200 mg, all women had early endometrial bleeding. Four women with early menses had concurrent functional luteolysis (one at 10, 50, 100 and 200 mg). There were no biochemical or clinical signs of toxicity, and no effect on urinary cortisol or circulating thyroxine, prolactin, adrenocorticotrophic hormone or renin levels. Higher serum equivalents of CDB-2914 were observed by radioimmunoassay than by high performance liquid chromatography detection, indicating a considerable contribution of metabolites. CONCLUSIONS: Mid-luteal administration of CDB-2914 antagonizes progesterone action on the endometrium, in a dose-dependent fashion, without apparent antiglucocorticoid effects. Further study of CDB-2914 is needed to determine its clinical role.

Statin use, clinical fracture, and bone density in postmenopausal women: results from the Women's Health Initiative Observational Study.

BACKGROUND: 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) have been shown to stimulate bone formation in laboratory studies, both in vitro and in vivo. While early epidemiologic studies showed lower risk for hip fracture among statin users than nonusers, subsequent studies have produced mixed results. OBJECTIVE: To examine the association of statin use with incidence of hip, lower arm or wrist, and other clinical fractures and with baseline levels of bone density. DESIGN: Prospective study. SETTING: Women's Health Initiative Observational Study conducted in 40 clinical centers in the United States. PARTICIPANTS: 93 716 postmenopausal women ages 50 to 79 years. MEASUREMENTS: Rates of hip, lower arm or wrist, and other clinical fractures were compared among 7846 statin users and 85 870 nonusers over a median follow-up of 3.9 years. In 6442 women enrolled at three clinical centers, baseline levels of total hip, posterior-anterior spine, and total-body bone density measured by using dual-energy x-ray absorptiometry were compared according to statin use. RESULTS: Age-adjusted rates of hip, lower arm or wrist, and other clinical fractures were similar between statin users and nonusers regardless of duration of statin use. The multivariate-adjusted hazard ratios for current statin use were 1.22 (95% CI, 0.83 to 1.81) for hip fracture, 1.04 (CI, 0.85 to 1.27) for lower arm or wrist fracture, and 1.11 (CI, 1.00 to 1.22) for other clinical fracture. Bone density levels did not statistically differ between statin users and nonusers at any skeletal site after adjustment for age, ethnicity, body mass index, and other factors. CONCLUSION: Statin use did not improve fracture risk or bone density in the Women's Health Initiative Observational Study. The cumulative evidence does not warrant use of statins to prevent or treat osteoporosis.