M.I. Whitehead

Pulsatility index in internal carotid artery in relation to transdermal oestradiol and time since menopause

The protection afforded by postmenopausal oestrogen replacement against cardiovascular disease is not fully explained by changes in plasma lipoproteins. To investigate the effect of oestrogen on arterial tone, Doppler ultrasound was used to assess blood flow characteristics in the internal carotid arteries of 12 postmenopausal women. Patients were studied pretreatment and at weeks 4, 6, 9, and 22 of therapy with transdermal oestradiol 50 micrograms/day. The pulsatility index (PI), which is thought to represent impedance to blood flow distal to the point of sampling, was measured from the flow velocity waveform. 11 of the 12 patients were within 5 years of menopause; 1 was 8 years postmenopausal but had experienced bleeding 4 years after menopause. In the 11 women there was a highly significant correlation (r = 0.77) between time since menopause and baseline PI. A similar correlation (r = 0.74) was observed when the episode of postmenopausal bleeding was redefined as time of menopause in the twelfth patient. For all 12 patients, there was a significant negative correlation (r = -0.70) between change in PI during transdermal oestradiol therapy and mean of baseline plus week 22 PI value. For all correlations between changes in PI and time since menopause, the longer the time the greater the fall in PI. These results, and previous observations of a reduction in uterine artery PI with oestradiol treatment, suggest that oestrogen has a generalised effect on the arterial system.

CALCITONIN FOR PREVENTION OF POSTMENOPAUSAL BONE LOSS

A 2-year randomised pilot study was conducted in 70 patients to see whether the osteoclast-inhibiting effect of calcitonin would reduce postmenopausal vertebral bone loss. An oestradiol-treated group was included in the study as a positive control since oestrogens are known to be effective. Calcitonin reduced vertebral bone loss in doses above 250 micrograms human calcitonin (50 international units) a week, and at this dose was as effective as oestradiol.

CALCITONIN AND THE CALCIUM-REGULATING HORMONES IN POSTMENOPAUSAL WOMEN: EFFECT OF OESTROGENS

In man, the major function of calcitonin appears to be prevention of excessive or unwanted bone resorption. There is a striking sex difference in circulating levels, with a relative deficiency in women. Calcitonin secretion in young adults is increased by oestrogens and therefore long periods of oestrogen lack, such as after the menopause, may be associated with a more pronounced calcitonin deficiency. This exaggerated deficiency could be an important factor in the pathogenesis of postmenopausal bone loss, especially since the latter may be due to excessive bone resorption. In a study of the effects of oestrogen treatment on circulating levels of calcitonin, parathyroid hormone, and vitamin-D metabolites in postmenopausal women, the most striking change was a sharp rise in plasma-calcitonin. Oestrogens prevent postmenopausal bone loss, and it is suggested that this effect could be mediated, at least in part, through control of calcitonin secretion. Calcitonin may prove effective in the prevention of postmenopausal bone loss, and it is suggested that this effect could be mediated, at least in part, through control of calcitonin secretion. Calcitonin may prove effective in the prevention of postmenopausal bone loss. Its place in the treatment of postmenopausal osteoporosis warrants further evaluation.

A PHYSIOLOGICAL ROLE FOR CALCITONIN: PROTECTION OF THE MATERNAL SKELETON

Plasma-calcitonin levels, measured with an established and reliable extraction radioimmunoassay technique, were significantly higher throughout normal pregnancy and lactation than in normal non-pregnant women, and were not immediately influenced by the acute stimulation of breast-feeding. Thus, more calcitonin circulates at times of physiologically increased calcium need. It is suggested that an important function of calcitonin is the protection of the healthy maternal skeleton from excessive resorption by opposing the resorptive action of 1,25-dihydroxycholecalciferol on bone.

Long-term effects of transdermal and oral hormone replacement therapy on postmenopausal bone loss

Transdermal hormone replacement therapy (HRT) is now an accepted form of treatment, but the long-term skeletal effects have not been assessed. Sixty-six early postmenopausal women were randomized to receive either transdermal HRT (continuous 17β-oestradiol 0.05 mg/day, with 0.25 mg/day of norethisterone acetate added for 14 days of each 28-day cycle) or oral HRT (continuous conjugated equine oestrogens 0.625 mg/day, with 0.15 mg/day dl-norgestrel added for 12 days of each 28-day cycle). Treatment was given for 3 years and 30 matched untreated women were studied concurrently as a control group. Bone density was measured in the lumbar spine and proximal femur by dual-photon absorptiometry at 6-monthly intervals. Bone turnover was assessed by measurement of biochemical markers. At 3 years bone density had declined by 4% in the lumbar spine and by more than 5% in the femoral neck in the untreated group. By comparison bone density increased in both treatment groups at both sites (p<0.001 vs. untreated) and biochemical measurements indicated a significant reduction in bone turnover. There were no significant differences between the treatment groups. Twelve per cent of women on transdermal or oral treatments lost a significant amount of bone from the femoral neck by 3 years despite adequate compliance. Women taking therapy primarily for hip fracture prevention may require a follow-up bone density measurement to establish the efficacy of treatment.

Efficacy, acceptability, and metabolic effects of transdermal estradiol in the management of postmenopausal women

Systemic side effects that result from oral administration of estrogens to postmenopausal women may be minimized by use of the transdermal route. We administered transdermal estradiol, 0.05 mg/day, cyclically for 3 months to 12 postmenopausal and perimenopausal women to study the efficacy, acceptability, and metabolic effects of this dosage form. The results showed that transdermal estradiol significantly increased plasma levels of estradiol and estrone and urinary concentrations of estradiol conjugates, and produced significant improvement in menopausal symptoms and vaginal cytologic findings. The patches were well tolerated and no systemic side effects were reported. No clinically significant adverse biochemical changes were observed. Plasma renin substrate and renin activity were unchanged during therapy.

Transdermal administration of oestrogen/progestagen hormone replacement therapy

The effects of an oestrogen/progestagen transdermal therapeutic system (TTS) were evaluated in sixteen oestrogen-deficient women. The patients applied conventional oestradiol-TTS for 14 days, then two combined norethisterone acetate/oestradiol patches for a further 14 days. The treatment was repeated for five cycles. Ten patients then underwent metabolic studies. One patient had amenorrhoea, but the rest experienced regular withdrawal bleeding which was seldom heavy. Fourteen endometrial biopsy samples were taken during the fifth treatment cycle; none showed proliferative or hyperplastic features. The effects of transdermal norethisterone acetate on symptoms, lipid metabolism, and psychological status were determined by comparing features in the oestrogen-only phase and in the combined phase; the effects were very mild. These preliminary findings show that transdermal progestagen can be successfully administered in hormone replacement therapy to prevent endometrial proliferation while minimising the adverse effects that may be seen with oral administration.

Ovarian size in postmenopausal women

Summary. Ovarian volumes have been determined by pelvic ultrasonography in 2246 apparently healthy postmenopausal women of whom 2221 were included in the statistical analysis. Factors associated with gonadal size have been identified, and reference ranges for derived indices have been determined for use (in association with criteria for abnormal morphology) in a screening programme for ovarian carcinoma. The right ovary was present in 98·9% of subjects and the left in 99 · 1 %. The mean (SD; range) of right and left ovarian volumes were 3·58 (1·40; 1·00–14.01) and 3·57 (1·37; 0·88–10·9) ml respectively. Significant predictors of ovarian volume were years since the menopause, weight, parity, age at menopause, a history of hormone replacement therapy, and previously diagnosed breast cancer. Abnormal ovarian volumes were assessed from a score equal to the (observed mean log volume (MLV) minus the predicted MLV)/0·327. A simplified nomogram has been prepared for routine clinical use. The relative abnormality of one ovary was assessed from a ratio score equal to loge (larger ovarian volume/smaller ovarian volume)/0·211 compared with the 99th centile for the Gaussian distribution.

Continuous combined conjugated equine estrogen—progestogen therapy: Effects of medroxyprogesterone acetate and norethindrone acetate on bleeding patterns and endometrial histologic diagnosis*

OBJECTIVES: This study was designed to assess the incidence of amenorrhea with continuous combined therapy by using two different progestogens and to determine whether early bleeding predicts subsequent bleeding and endometrial response. STUDY DESIGN: Seventy-nine postmenopausal women on sequential estrogen-progestogen treatment were switched to continuous combined estrogen-progestogen therapy comprising conjugated equine estrogens 0.625 mg daily with either norethindrone acetate 0.35 mg twice daily or medroxyprogesterone acetate 2.5 mg twice daily added continuously for 78 weeks. All bleeding was recorded, and endometrial biopsies were performed at 26 and 78 weeks. RESULTS: Only one third of the women who starting the study had amenorrhea by week 78, but 46 (62%) of these women had withdrawn, mainly because of chronic irregular bleeding. Endometrial atrophy was observed in the majority of biopsy specimens. The two progestogens had similar effects. Bleeding patterns were useful predictors of subsequent bleeding, but not of endometrial response. CONCLUSIONS: Persistent irregular bleeding is common with continuous combined estrogen-progestogen therapy. Women with persistent early bleeding should probably revert to sequential treatment. Regular endometrial sampling is advised.

The role of estradiol dehydrogenase in mediating progestin effects on endometrium from postmenopausal women receiving estrogens and progestins

Endometria from postmenopausal women taking estrogens exhibit little estradiol dehydrogenase activity and contain appreciable amounts of nuclear estradiol receptor. Ingestion of the synthetic progestin, norethisterone, markedly elevates the dehydrogenase activity and decreases the nuclear estradiol receptor content of the endometria. The quantitative relationship between enzyme activity and receptor binding has been studied in women receiving different daily dosages of norethisterone. Statistically, the best negative correlation is obtained when log receptor is plotted against log dehydrogenase. Thus, a small rise in dehydrogenase activity produces a disproportionate decrease in nuclear receptor. Estradiol dehydrogenase in postmenopausal endometria preferentially metabolizes estradiol into estrone. Separation of endometria into glandular and stromal elements indicates that although the dehydrogenase is present in both fractions it is concentrated in the epithelial glands. The functional significance of changes in receptor and dehydrogenase activity was studied by [3H]-thymidine autoradiography. Induction of the dehydrogenase was accompanied by an inhibition of DNA synthesis in both epithelial and stromal cells and the quantitative interrelationships are complex. The nuclear estradiol receptor content, estradiol dehydrogenase activity and DNA synthesis of the postmenopausal endometria have been compared with premenopausal samples from untreated women.