Vitamin D and calcium dysregulation in the polycystic ovarian syndrome

Over the past 30 years, numerous studies in invertebrates and vertebrates have established a role of calcium in oocyte maturation as well as in the resumption and progression of follicular development. Polycystic ovarian syndrome (PCO) is characterized by hyperandrogenic chronic anovulation, theca cell hyperplasia, and arrested follicular development. The aim of this observational study was to determine whether vitamin D and calcium dysregulation contribute to the development of follicular arrest in women with PCO, resulting in reproductive and menstrual dysfunction. Thirteen premenopausal women (mean age 31 +/- 7.9 years) with documented chronic anovulation and hyperandrogenism were evaluated. Four women were amenorrheic and nine had a history oligomenorrhea, two of whom had dysfunctional bleeding. Nine had abnormal pelvic sonograms with multiple ovarian follicular cysts. All were hirsute, two had alopecia, and five had acanthosis nigricans. The mean 25 hydrovitamin D was 11.2 +/- 6.9 ng/ml [normal (nl): 9-52], and the mean 1,25 dihydroxyvitamin D was 45.8 +/- 18 pg/ml. with one woman with a 1,25 dihydroxyvitamin D <5 pg/ml (nl: 15-60). The mean intact parathyroid hormone level was 47 +/- 19 pg/ml (nl: 10-65), with five women with abnormally elevated parathyroid hormone levels. All were normocalcemic (9.3 +/- 0.4 mg/dl). Vitamin D repletion with calcium therapy resulted in normalized menstrual cycles within 2 months for seven women, with two experiencing resolution of their dysfunctional bleeding. Two became pregnant, and the other four patients maintained normal menstrual cycles. These data suggest that abnormalities in calcium homeostasis may be responsible, in part, for the arrested follicular development in women with PCO and may contribute to the pathogenesis of PCO.

A case of fatal pulmonary thromboembolism associated with the use of intravenous estrogen therapy

OBJECTIVE

To report a case of fatal pulmonary embolism associated with the use of i.v. estrogen therapy for menometrorrhagia.

DESIGN

Case report.

SETTING

University hospital.

PATIENT(S)

A 52-year-old woman with fibroid uterus treated with GnRH analogues with add-back therapy who presented with excessive vaginal bleeding.

INTERVENTION(S)

Intravenous conjugated estrogens were administered for a total of six doses.

MAIN OUTCOME MEASURE(S)

Fatal thromboembolic event.

RESULT(S)

The day after i.v. conjugated estrogens were administered, the patient had only scant vaginal bleeding, but she experienced the sudden onset of respiratory distress, became comatose, and subsequently had ventricular fibrillation leading to asystole. All resuscitative efforts failed. Postmortem examination revealed bilateral pulmonary artery thromboembolism (saddle embolus).

CONCLUSION(S)

Intravenous conjugated estrogen therapy may be complicated by fatal thromboembolic events. This potential adverse effect must be considered in the use of such therapy for severe menometrorrhagia, especially when treating a patient at increased risk.

Estrogen and estrogen-androgen replacement in postmenopausal women dissatisfied with estrogen-only therapy. Sexual behavior and neuroendocrine responses

OBJECTIVE

To investigate the efficacy of esterified estrogens alone and combined with oral androgen on sexual function and menopausal symptoms in postmenopausal women.

STUDY DESIGN

Twenty postmenopausal women dissatisfied with their estrogen or estrogen-progestin therapy volunteered to enter a double-blind, randomized trial in which they received either oral esterified estrogens or esterified estrogens + androgen for eight weeks after a single-blind, placebo, lead-in period. Sexual function was assessed with a questionnaire used in the Yale midlife survey, and plasma levels of estradiol, estrone, sex hormone binding globulin (SHBG) and beta-endorphin were measured at two- to four-week intervals.

RESULTS

Estrogen-androgen therapy significantly improved sexual sensation and desire after four and eight weeks of double-blind treatment in comparison to previous estrogen therapy and postplacebo baseline assessments. Plasma levels of estradiol and estrone increased significantly in all patients as compared to the postplacebo baseline and decreased in comparison to circulating estrogen concentrations on previous therapy. Relative proportions of free and bound steroid hormone exhibited contrasting shifts during estrogen and estrogen-androgen therapy. SHBG increased in the estrogen group and decreased in the estrogen-androgen group, leading to lower amounts of free androgens during estrogen therapy and increased free androgen levels during estrogen-androgen therapy. Since proportions of free (bioavailable) ovarian steroids would correlate inversely with plasma protein binding capacity, the beneficial effects of oral estrogen-androgen therapy on sexual sensation and desire may be due either to the administered androgen or to the increased availability of endogenous and exogenous androgens, particularly in the central nervous system.

CONCLUSION

Sexual desire, satisfaction and frequency in postmenopausal women taking hormonal therapy were improved significantly by combined estrogen-androgen therapy but not by estrogen or estrogen-progestin therapy. Sexual function improved with estrogen-androgen therapy even though circulating estrogen levels were lower than those measured during previous estrogen therapy. This leads to the conclusion that androgens play a pivotal role in sexual function but that estrogens are not a significant factor determining levels of sexual drive and enjoyment.

17 beta-estradiol regulation of human endothelial cell basal nitric oxide release, independent of cytosolic Ca2+ mobilization

Estradiol retards the development of atherosclerosis. Animal models have suggested that NO may be a critical effector molecule in this cardiovascular protection. In this study, female human umbilical vein endothelial cells (HUVECs) were propagated in phenol red-free gonadal hormone-free medium and pretreated with 17 beta-estradiol (E2). Reduced NO2- and NO3- (NOx) concentration, determined by chemiluminescence, demonstrated a rapid increase in basal HUVEC NO release in response to physiological concentrations of E2. The estrogen receptor (ER) antagonist ICI 164,384 inhibited the augmented NO release, demonstrating an ER-mediated component of this response. Because endothelial NO synthase (eNOS) activity is largely regulated by cytosolic Ca2+, relative [Ca2+]i in response to E2 was determined in a fluorometric assay. E2 did not promote HUVEC Ca2+ fluxes. Furthermore, eNOS activity in E2-pretreated endothelial whole-cell lysates was not dependent on additional Ca2+. Despite involving the ER, this is a nongenomic effect E2, as demonstrated by maintained responses in transcriptionally inhibited cells and by the rapidly (10 minutes) of cGMP formation in an NO bioassay. We demonstrate, for the first time, that independent of cytosolic Ca2+ mobilization, there is augmentation of eNOS activity with a resultant increase in HUVEC basal NO release in response to short-term estradiol exposure. Implications for the cardiovascular protective role of estrogen are discussed.

Middle cerebral artery blood velocity during controlled ovarian hyperstimulation

OBJECTIVE

To measure cerebral blood flow velocities using transcranial Doppler during ovulation induction after pituitary suppression.

DESIGN

Women undergoing controlled ovarian hyperstimulation after pituitary suppression were prospectively studied.

SETTING

Tertiary institution.

PATIENTS

A microprocessor-controlled directional pulsed-wave adjustable hand held probe (2 MHz) was used to measure blood flow velocities and pulsatility indices in the right and left middle cerebral arteries (middle cerebral artery) in nine patients. Measurements of peak middle cerebral artery velocities (cm/s) and pulsatility index were obtained after achieving pituitary suppression with leuprolide acetate and repeated over several days after treatment with human menopausal gonadotropin (225 IU/d).

RESULTS

There was a significant increase in the peak middle cerebral artery velocities (cm/s) of the patients measured at the time of pituitary suppression when compared with those obtained at the time of maximal estradiol (E2) (98 +/- 12 versus 105 +/- 12, P less than 0.03). The pulsatility index also showed a significant increase from 0.72 +/- 0.08 at the time of pituitary suppression to 0.82 +/- 0.04 at the time of maximal hyperestrogenism, P less than 0.002. Estradiol values obtained at the time of the transcranial Doppler examinations were normalized by transformation to their natural logarithms (LnE2). The middle cerebral artery velocities were significantly correlated with LnE2 levels (P less than 0.0001 and r = 0.93).

CONCLUSION

Estrogen levels appear to be directly correlated with cerebral blood flow velocity and pulsatility index, implying an effect of ovarian steroids on cerebrovascular hemodynamics.

The effect of hysterectomy on the age at ovarian failure: identification of a subgroup of women with premature loss of ovarian function and literature review

The age at ovarian failure was determined in 90 women who had previously undergone abdominal hysterectomy with bilateral ovarian conservation and in 226 women who had undergone a spontaneous menopause. The mean age of ovarian failure in the hysterectomized group was 45.4 +/- 4.0 years (standard deviation), and this was significantly lower than the mean age of 49.5 +/- 4.04 years in the nonhysterectomized control group (P less than 0.001). There was a significant correlation between the age at hysterectomy and the age of ovarian failure in the women who were 44 years or less at the time of ovarian failure (r = 0.62, P less than 0.001), implying a causal relationship. The indication for hysterectomy did not influence the time of ovarian failure. Two explanations are proposed as to how conventional surgery for hysterectomy may adversely affect ovarian function.