Skeletal effects of oral oestrogen compared with subcutaneous oestrogen and testosterone in postmenopausal women

Androgens and Androgen Receptor Actions on Bone Health and Disease: From Androgen Deficiency to Androgen Therapy

Androgens are not only essential for bone development but for the maintenance of bone mass. Therefore, conditions with androgen deficiency, such as male hypogonadism, androgen-insensitive syndromes, and prostate cancer with androgen deprivation therapy are strongly associated with bone loss and increased fracture risk. Here we summarize the skeletal effects of androgens—androgen receptors (AR) actions based on in vitro and in vivo studies from animals and humans, and discuss bone loss due to androgens/AR deficiency to clarify the molecular basis for the anabolic action of androgens and AR in bone homeostasis and unravel the functions of androgen/AR signaling in healthy and disease states. Moreover, we provide evidence for the skeletal benefits of androgen therapy and elucidate why androgens are more beneficial than male sexual hormones, highlighting their therapeutic potential as osteoanabolic steroids in improving bone fracture repair. Finally, the application of selective androgen receptor modulators may provide new approaches for the treatment of osteoporosis and fractures as well as building stronger bones in diseases dependent on androgens/AR status.

DHEA, important source of sex steroids in men and even more in women

A major achievement from 500 million years of evolution is the establishment of a high secretion rate of dehydroepiandrosterone (DHEA) by the human adrenal glands coupled with the indroduction of menopause which stops secretion of estrogens by the ovary. Cessation of estrogen secretion at menopause eliminates the risks of endometrial hyperplasia and cancer which would result from non-opposed estrogen stimulation during the post-menopausal years. In fact, from the time of menopause, DHEA becomes the exclusive and tissue-specific source of sex steroids for all tissues except the uterus. Intracrinology, a term coined in 1988, describes the local formation, action and inactivation of sex steroids from the inactive sex steroid precursor DHEA. Over the past 25 years most, if not all, the genes encoding the human steroidogenic and steroid-inactivating enzymes have been cloned and sequenced and their enzymatic activity characterized. The problem with DHEA, however, is that its secretion decreases from the age of 30 years and is already decreased, on average, by 60% at time of menopause. In addition, there is a large variability in the circulating levels of DHEA with some post-menopausal women having barely detectable serum concentrations of the steroid while others have normal values. Since there is no feedback mechanism controlling DHEA secretion within 'normal' values, women with low DHEA will remain with such a deficit of sex steroids for their remaining lifetime. Since there is no other significant source of sex steroids after menopause, one can reasonably believe that low DHEA is involved, in association with the aging process, in a series of medical problems classically associated with post-menopause, namely osteoporosis, muscle loss, vaginal atrophy, fat accumulation, hot flashes, skin atrophy, type 2 diabetes, memory loss, cognition loss and possibly Alzheimer's disease. A recent randomized, placebo-controlled study has shown that all the signs and symptoms of vaginal atrophy, a classical problem recognized to be due to the hormone deficiency of menopause, can be rapidly improved or corrected by local administration of DHEA without systemic exposure to estrogens. In addition, the four domains of sexual dysfucntion are improved. For the other problems of menopause, although similar large scale, randomized and placebo-controlled studies usually remain to be performed, the available evidence already strongly suggests that they could be improved, corrected or even prevented by exogenous DHEA. In men, the contribution of adrenal DHEA to the total androgen pool has been measured at 40% in 65-75-year-old men. Such data stress the necessity of blocking both the testicular and adrenal sources of androgens in order to achieve optimal benefits in prostate cancer therapy. On the other hand, the comparable decrease in serum DHEA levels observed in both sexes has less consequence in men who continue to receive a practically constant supply of testicular sex steroids during their whole life. In fact, in men, the appearance of hormone-deficiency symptoms common to women is observed at a later age and with a lower degree of severity. Consequently, DHEA replacement has shown much more easily measurable beneficial effects in women. Most importantly, despite the non-scientific and unfortunate availability of DHEA as a food supplement in the United States, a situation that discourages rigorous clinical trials on the crucial physiological and therapeutic role of DHEA, no serious adverse event related to DHEA has ever been reported in the world literature (thousands of subjects exposed) or in the monitoring of adverse events by the FDA (millions of subjects exposed), thus indicating, as expected from its known physiology, the excellent safety profile of DHEA. With today's knowledge, one can reasonably suggest that DHEA offers the promise of a safe and efficient replacement therapy for the multiple problems related to hormone deficiency after menopause without the risks associated with estrogen-based or any other treatments.

Testosterone enhances estradiol's effects on postmenopausal bone density and sexuality

To investigate the role of androgens in increasing bone density and improving low libido in postmenopausal women, we have studied the long-term effects of estradiol and testosterone implants on bone mineral density and sexuality in a prospective, 2 year, single-blind randomised trial. Thirty-four postmenopausal volunteers were randomised to treatment with either estradiol implants 50 mg alone (E) or estradiol 50 mg plus testosterone 50 mg (E&T), administered 3-monthly for 2 years. Cyclical oral progestins were taken by those women with an intact uterus. Thirty-two women completed the study. BMD (DEXA) of total body, lumbar vertebrae (L1-L4) and hip area increased significantly in both treatment groups. BMD increased more rapidly in the testosterone treated group at all sites. A substantially greater increase in BMD occurred in the E&T group for total body (P < 0.008), vertebral L1-L4 (P < 0.001) and trochanteric (P < 0.005) measurements. All sexual parameters (Sabbatsberg sexual self-rating scale) improved significantly in both groups. Addition of testosterone resulted in a significantly greater improvement compared to E for sexual activity (P < 0.03), satisfaction (P < 0.03), pleasure (P < 0.01), orgasm (P < 0.035) and relevancy (P < 0.05). Total cholesterol and LDL-cholesterol fell in both groups as did total body fat. Total body fat-free mass (DEXA, anthropometry, impedance) increased in the E&T group only. We concluded that in postmenopausal women, treatment with combined estradiol and testosterone implants was more effective in increasing bone mineral density in the hip and lumbar spine than estradiol implants alone. Significantly greater improvement in sexuality was observed with combined therapy, verifying the therapeutic value of testosterone implants for diminished libido in postmenopausal women. The favourable estrogenic effects on lipids were preserved in women treated with T, in association with beneficial changes in body composition.

Might DHEA be considered a beneficial replacement therapy in the elderly?

Dehydroepiandrosterone (DHEA) [prasterone] is typically secreted by the adrenal glands and its secretory rate changes throughout the human lifespan. When human development is completed and adulthood is reached, DHEA and DHEA sulphate (DHEAS) [PB-008] levels start to decline so that at 70-80 years of age, peak DHEAS concentrations are only 10-20% of those in young adults. This age-associated decrease has been termed 'adrenopause', and since many age-related disturbances have been reported to begin with the decline of DHEA/DHEAS levels, this provides a potential opportunity for use of DHEA as replacement therapy. For these reasons, use of DHEA as a replacement therapy in aging men and women has been proposed and this paper outlines the reported beneficial effects of such treatment in humans. Many interesting results have been obtained in experimental animals suggesting that DHEA positively modulates most age-related disturbances. However, renewed interest in DHEA has arisen as a result of recent studies suggesting that DHEA appears to be beneficial in hypoandrogenic men as well as in postmenopausal and aging women. Menopause is the event in a woman's life that induces a dramatic change in the steroid milieu, and use of DHEA as 'replacement treatment' has been reported to restore both the androgenic and estrogenic environment and reduce most of the symptoms of this change. As menopause is the beginning of the biological transition of women towards senescence, it is of great interest to better understand how DHEA might help to solve and/or overcome the problems of this complex stage of life. In men with adrenal insufficiency and hypogonadism without androgen replacement, DHEA administration results in a significant increase in circulating androgens. Though most data are suggestive for use of DHEA as hormonal replacement treatment, more defined and specific clinical trials are needed to uncover all of the 'secrets' and features of this steroid before it can be used as a standard treatment. Furthermore, DHEA is perceived differently around the world, being considered only a 'dietary supplement' in the US, while in many European countries it is considered a 'true hormone' that has not been approved for use as a hormonal treatment by the European health authorities. This overview offers some points of view on use of DHEA as an experimental hormonal replacement therapy.

Testosterone for peri- and postmenopausal women

BACKGROUND

: The value of adding testosterone to hormone therapy (HT) for the management of peri- and postmenopausal women is controversial and has not been systematically reviewed.

OBJECTIVES

: To determine the benefits and risks of testosterone therapy for peri- and postmenopausal women taking hormone therapy.

SEARCH STRATEGY

: We searched the Cochrane Menstrual Disorders and Subfertility Group Trials Register (1st November 2003), The Cochrane Library (Issue 2, 2003), MEDLINE (1966 to 1st November 2003), EMBASE (1980 to 1st November 2003), Biological Abstracts (1969 to 2002), PsycINFO (1972 to 1st November 2003), CINAHL (1982 to 1st November 2003), and reference lists of articles. We also contacted pharmaceutical companies and researchers in the field.

SELECTION CRITERIA

: Studies that were randomized comparisons of testosterone plus hormone therapy versus hormone therapy alone in peri- or postmenopausal women.

DATA COLLECTION AND ANALYSIS

: Two review authors assessed the quality of the trials and extracted data independently. Where it was necessary, the corresponding authors of eligible trials were contacted for additional information. For dichotomous outcomes Peto odds ratios and 95% confidence intervals were calculated. For continuous outcomes non-skewed data from valid scales were synthesized using a weighted mean difference or standardized mean difference. If statistical heterogeneity was found, a random-effects model was used and reasons for the heterogeneity were explored and discussed.

MAIN RESULTS

: Twenty-three trials with 1957 participants were included in the review. The median study duration was 6 months (range 1.5 to 24 months). Most of the trials were of adequate quality with regard to randomization and concealment of allocation sequence. The major methodological limitations were attrition bias and lack of a washout period in the cross-over studies. The pooled estimate from the studies suggested that the addition of testosterone to HT regimens improved sexual function scores for postmenopausal women. A significant adverse effect was a decrease in high-density lipoprotein (HDL) cholesterol levels. The discontinuation rate was not significantly greater with testosterone therapy (Peto odds ratio 1.01, 95% confidence interval 0.76 to 1.33) than with HT alone. There was insufficient evidence of a treatment effect for perimenopausal women or for other outcomes.

AUTHORS' CONCLUSIONS

: Only a limited number of studies could be pooled in the meta-analyses. This limited the power of the meta-analysis to provide conclusions about efficacy and safety. However, there is evidence that adding testosterone to HT has a beneficial effect on sexual function in postmenopausal women. There was a reduction in HDL cholesterol associated with the addition of testosterone to the HT regimens. The meta-analysis combined studies using different testosterone regimens. It is, therefore, difficult to estimate the effect of testosterone on sexual function in association with any individual hormone treatment regimen.

Endocrine and intracrine sources of androgens in women: inhibition of breast cancer and other roles of androgens and their precursor dehydroepiandrosterone

Serum androgens as well as their precursors and metabolites decrease from the age of 30-40 yr in women, thus suggesting that a more physiological hormone replacement therapy at menopause should contain an androgenic compound. It is important to consider, however, that most of the androgens in women, especially after menopause, are synthesized in peripheral intracrine tissues from the inactive precursors dehydroepiandrosterone (DHEA) and DHEA sulfate (DHEA-S) of adrenal origin. Much progress in this new area of endocrine physiology called intracrinology has followed the cloning and characterization of most of the enzymes responsible for the transformation of DHEA and DHEA-S into androgens and estrogens in peripheral target tissues, where the locally produced sex steroids are exerting their action in the same cells in which their synthesis takes place without significant diffusion into the circulation, thus seriously limiting the interpretation of serum levels of active sex steroids. The sex steroids made in peripheral tissues are then inactivated locally into more water-soluble compounds that diffuse into the general circulation where they can be measured. In a series of animal models, androgens and DHEA have been found to inhibit breast cancer development and growth and to stimulate bone formation. In clinical studies, DHEA has been found to increase bone mineral density and to stimulate vaginal maturation without affecting the endometrium, while improving well-being and libido with no significant side effects. The advantage of DHEA over other androgenic compounds is that DHEA, at physiological doses, is converted into androgens and/or estrogens only in the specific intracrine target tissues that possess the appropriate physiological enzymatic machinery, thus limiting the action of the sex steroids to those tissues possessing the tissue-specific profile of expression of the genes responsible for their formation, while leaving the other tissues unaffected and thus minimizing the potential side effects observed with androgens or estrogens administered systemically.

Hormone replacement therapy: current controversies

Postmenopausal hormonal therapy is used to manage the climacteric symptoms that impair the quality of life of a substantial number of women. The difficulty is achieving the desired effects with minimal side-effects and no adverse health risks. Fundamental to this is understanding the physiology of oestrogen in women and the metabolism of the therapeutic compounds. Although the effects of oral oestrogen therapy have been studied extensively, there is insufficient evidence to assess adequately the independent effects of progestin use, other oestrogen compounds, differing doses and duration of treatment. We have reviewed some basic concepts of oestrogen physiology and how these relate to exogenous oestrogen administration, the risks of greatest concern, and the role of androgens and newer treatment alternatives.

Androgens in postmenopausal women: production, possible role, and replacement options

The physiology of normal androgen production in women has not been well understood. Aging, per se, accounts for much of the reduction in both ovarian and adrenal androgen production; and natural menopause does not result in an abrupt decline in testosterone production. Therefore, the definition of an androgen deficiency state in women, in the absence of adrenal suppression and/or bilateral oophorectomy, has been difficult. Nevertheless there are well-documented beneficial effects of androgen on many organ systems, including bone and the brain. This review focuses on the physiology of androgens in postmenopausal women and includes a discussion of the definition of an androgen deficiency state, the anticipated effects of androgen on several parameters of health, and possible ways in which androgens may be administered to women.

Sex steroids and bone

Sex steroids are essential for skeletal development and the maintenance of bone health throughout adult life, and estrogen deficiency at menopause is a major pathogenetic factor in the development of osteoporosis in postmenopausal women. The mechanisms by which the skeletal effects of sex steroids are mediated remain incompletely understood, but in recent years there have been considerable advances in our knowledge of how estrogens and, to a lesser extent androgens, influence bone modeling and remodeling in health and disease. New insights into estrogen receptor structure and function, recent discoveries about the development and activity of osteoclasts, and lessons learned from human and animal genetic mutations have all contributed to increased understanding of the skeletal effects of estrogen, both in males and females. Studies of untreated and treated osteoporosis in postmenopausal women have also contributed to this knowledge and have provided unequivocal evidence for the potential of high-dose estrogen therapy to have anabolic skeletal effects. The development of selective estrogen receptor modulators has provided a new approach to the prevention of osteoporosis and other major diseases of menopause and has implications for the therapeutic use of other steroid hormones, including androgens. Further elucidation of the mechanisms by which sex steroids affect bone thus has the potential to improve the clinical management not only of osteoporosis, both in men and women, but also of a number of other diseases related to sex hormone status.

A comparison of 25 mg and 50 mg oestradiol implants in the control of climacteric symptoms following hysterectomy and bilateral salpingo-oophorectomy

OBJECTIVES

1. To compare the effects of 25 mg and 50 mg oestradiol implants on serum follicle stimulating hormone and oestradiol levels; and 2. to assess the relationship of the dose of oestradiol implant and serum oestradiol on the effectiveness and duration of climacteric symptom control.

DESIGN

Randomised, double-blind investigation.

PARTICIPANTS

Forty-four women, who had undergone total abdominal hysterectomy and bilateral salpingo-oophorectomy.

METHODS

The women were randomised to receive either 25 mg (n = 20) or 50 mg (n = 24) oestradiol implants. Follow up consisted of prospective symptom enquiry and hormone assays.

MAIN OUTCOME MEASURES

Primary: climacteric symptom control: duration and effectiveness; secondary: serum oestradiol and follicle stimulating hormone levels.

RESULTS

Serum oestradiol was significantly higher and serum follicle stimulating hormone significantly lower after the fourth month of treatment in women receiving 50 mg implants. No significant difference in symptom control was noted in the two groups. The mean duration of symptom control was similar in the two groups: 5.9 months (SD 2.4) in those receiving 50 mg oestradiol and 5.6 months (SD 2.3) in those receiving 25 mg.

CONCLUSION

The higher level, 50 mg oestradiol implants does not result in better control of symptoms nor in longer periods of symptom control compared with 25 mg oestradiol implants. In order to maximise compliance, 25 mg oestradiol implants should therefore be the treatment of choice for women with normal bone density seeking relief of climacteric symptoms.

Comparative effects of estrogens plus androgens and tibolone on bone, lipid pattern and sexuality in postmenopausal women

BACKGROUND

The main goals of estrogen replacement therapy (ERT) are the prevention of osteoporosis and cardioprotection and the improvement of quality of life (QL). Androgens and tibolone therapy may increase bone mineral density (BMD) to a greater extent than ERT and offer an increase in QL. Lipid and cardiovascular effects, however, are still a major concern.

AIM

To evaluate whether the addition of a weak androgen to ERT may improve postmenopausal bone loss and sexual activity without adverse effects on lipid pattern and to compare these effects with those observed after tibolone therapy.

SUBJECTS AND METHODS

This prospective study enrolled 120 surgical postmenopausal women; of these, 96 completed the 1-year follow-up. Patients were allocated to one of four groups. The first group (A; n = 23) received 4 mg of estradiol valerate plus 200 mg of enanthate of dihydroandrosterone im monthly. The second group (E; n = 26) received 50 microg/day of transdermal 17-b-estradiol continuously; the third (T; n = 23) received 2.5 mg of tibolone every day; and finally, the fourth group (C; n = 24) constituted a treatment-free control group. Bone mass (dual X-ray absorptiometry), serum total cholesterol, HDL, LDL, triglycerides, apolipoproteins A1 and B and sexual activity were evaluated before starting therapy and at the end of follow-up.

RESULTS

All active treatment groups showed an increase in BMD. This increase was higher in the A treatment group (4.08% P < 0.01). Sexuality improved significantly with therapy; however, tibolone and androgens increased scores to a greater extent than ERT. Androgen therapy was associated with significant increases in total cholesterol, LDL and triglycerides. Cholesterol and LDL fall into groups E and T, HDL into groups A and T and triglycerides in group T only.

CONCLUSION

The combined regimen of androgens and ERT increased vertebral bone mass and enhance sexual activity in postmenopausal women equal to that of tibolone and to a greater extent than ERT alone; its effects on lipids, however, are clearly adverse.

Terapêutica de reposição hormonal na osteoporose da pós menopausa

Os benefícios da terapia de reposição hormonal na prevenção e tratamento da osteoporose já são amplamente reconhecidos. Esta revisão tem por objetivo abordar os principais efeitos, mecanismos de ação e indicações dos principais esteróides utilizados na osteoporose da pós menopausa.

Are high levels of oestradiol after implants associated with features of dependence?

OBJECTIVE

To determine whether features of dependence develop in women receiving oestradiol implants, and if so, whether these features are related to serum oestradiol levels.

DESIGN

A questionnaire survey of women attending for implants over a six month period.

SETTING

An implant clinic in a district general hospital.

MAIN OUTCOME MEASURES

Psychological symptoms and their relationship to serum oestradiol levels.

RESULTS

Women with serum oestradiol levels below 500 pmol/L were generally asymptomatic of psychological symptoms.

CONCLUSION

Serum oestradiol levels of women receiving implants should be kept in the range of 300-500 pmol/L. Higher levels appear to be associated with the development of psychological symptoms which could be classified as features of dependence.

The rationale for physiological testosterone replacement in women

Androgens have an important physiological role in women. Not only are they the precursor hormones for oestrogen production in the ovaries and extragonadal tissues, but they also appear to act directly, via androgen receptors, throughout the body. Androgen levels decline with increasing age in women, who may experience a variety of physical symptoms secondary to androgen depletion, as well as physiological changes that affect their quality of life. In this chapter, the changes in androgens as women age are reviewed, and the rationale for physiological androgen, specifically testosterone replacement, in women is addressed.

The effect of six months treatment with a 100 mg daily dose of dehydroepiandrosterone (DHEA) on circulating sex steroids, body composition and muscle strength in age-advanced men and women

OBJECTIVE

The biological role of the adrenal sex steroid precursors--DHEA and DHEA sulphate (DS) and their decline with ageing remains undefined. We observed previously that administration of a 50 daily dose of DHEA for 3 months to age-advanced men and women resulted in an elevation (10%) of serum levels of insulin-like growth factor-I (IGF-I) accompanied by improvement of self-reported physical and psychological well-being. These findings led us to assess the effect of a larger dose (100 mg) of DHEA for a longer duration (6 months) on circulating sex steroids, body composition (DEXA) and muscle strength (MedX).

SUBJECTS AND DESIGN

Healthy non-obese age-advanced (50-65 yrs of age) men (n = 9) and women (n = 10) were randomized into a double-blind placebo-controlled cross-over trial. Sixteen subjects completed the one-year study of six months of placebo and six months of 100 mg oral DHEA daily.

MEASUREMENTS

Fasting early morning blood samples were obtained. Serum DHEA, DS, sex steroids, IGF-I, IGFBP-1, IGFBP-3, growth hormone binding protein (GHBP) levels and lipid profiles as well as body composition (by DEXA) and muscle strength (by MedX testing) were measured at baseline and after each treatment.

RESULTS

Basal serum levels of DHEA, DS, androsternedione (A), testosterone (T) and dihydrotestosterone (DHT) were at or below the lower range of young adult levels. In both sexes, a 100 mg daily dose of DHEA restored serum DHEA levels to those of young adults and serum DS to levels at or slightly above the young adult range. Serum cortisol levels were unaltered, consequently the DS/cortisol ratio was increased to pubertal (10:1) levels. In women, but not in men, serum A, T and DHT were increased to levels above gender-specific young adult ranges. Basal SHBG levels were in the normal range for men and elevated in women, of whom 7 of 8 were on oestrogen replacement therapy. While on DHEA, serum SHBG levels declined with a greater (P < 0.02) response in women (-40 +/- 8%; P = 0.002) than in men (-5 +/- 4%; P = 0.02). Relative to baseline, DHEA administration resulted in an elevation of serum IGF-I levels in men (16 +/- 6%, P = 0.04) and in women (31 +/- 12%, P = 0.02). Serum levels of IGFBP-1 and IGFBP-3 were unaltered but GHBP levels declined in women (28 +/- 6%; P = 0.02) not in men. In men, but not in women, fat body mass decreased 1.0 +/- 0.4 kg (6.1 +/- 2.6%, P = 0.02) and knee muscle strength 15.0 +/- 3.3% (P = 0.02) as well as lumbar back strength 13.9 +/- 5.4% (P = 0.01) increased. In women, but not in men, an increase in total body mass of 1.4 +/- 0.4 kg (2.1 +/- 0.7%; P = 0.02) was noted. Neither gender had changes in basal metabolic rate, bone mineral density, urinary pyridinoline cross-links, fasting insulin, glucose, cortisol levels or lipid profiles. No significant adverse effects were observed.

CONCLUSIONS

A daily oral 100 mg dose of DHEA for 6 months resulted in elevation of circulating DHEA and DS concentrations and the DS/cortisol ratio. Biotransformation to potent androgens near and slightly above the range of their younger counterparts occurred in women with no detectable change in men. Given this hormonal milieu, an increase in serum IGF-I levels was observed in both genders but dimorphic responses were evident in fat body mass and muscle strength in favour of men. These differences in response to DHEA administration may reflect a gender specific response to DHEA and/or the presence of confounding factor(s) in women such as oestrogen replacement therapy.

Adequacy of hormone replacement therapy for osteoporosis prevention assessed by serum oestradiol measurement, and the degree of association with menopausal symptoms

BACKGROUND

Patients on hormone replacement therapy (HRT) for osteoporosis prevention rather than menopausal symptom control may be asymptomatic, despite inadequate replacement and low serum oestradiol (E2) levels. In the primary health care setting, therapeutic monitoring of HRT is not carried out routinely so that patients with serum E2 levels inadequate to protect bone may be missed.

AIM

To determine the proportion of women on transdermal E2 preparations with serum E2 levels insufficient to protect bone and to assess the value of a questionnaire-derived menopausal symptom score (MSS) for detecting these patients.

METHOD

A cross-sectional analysis of 45 patients aged 35-70 years using transdermal E2 preparations obtained from a computer register of 14500 patients in a suburban practice. One blood sample was obtained from each patient at the time the MSS questionnaire was completed. Serum E2 concentration was measured using a fluoroimmunoassay and compared with the MSS. Levels below 150 pmol/l were considered to be insufficient to protect bone. The diagnostic accuracy of the MSS in screening for levels below 150 pmol/l was determined using receiver operating characteristic (ROC) curve analysis.

RESULTS

The median (95% CI) serum E2 was 147 pmol/l (126-198 pmol/l) and levels were below 150 pmol/l in 24 out of 45 patients. There was no difference in the MSS (median, 95% CI) between those with serum E2 < 150 pmol/l (8.5, 5.0-17) and > or = 150 pmol/l (9.0, 5.0-14; P = 0.477). The degree of association between the serum E2 and the MSS, using the Spearman rank correlation coefficient, rs (95% CI) was small and not significant (-0.04, -0.34 to 0.26; P = 0.398). ROC curve analysis revealed an area under the curve (95% CI) of 0.51 (0.33-0.68).

CONCLUSIONS

More than half the women were inadequately replaced to protect against osteoporosis. Furthermore, the MSS was of no value in screening for those with low serum E2 levels. Serum E2 levels should be monitored in women on HRT for osteoporosis prevention and the E2 dosage adjusted accordingly.

Salmon calcitonin nasal spray : An effective alternative to estrogen therapy in select postmenopausal women

The efficacy and safety of estrogen replacement therapy (ERT) and salmon calcitonin in the treatment of postmenopausal osteoporosis are reviewed with special consideration given to patients for whom ERT, the primary antiresorptive therapy for osteoporosis, is not indicated, tolerable, or is refused. The various formulations of estrogen and salmon calcitonin, for which the nasal spray formulation was recently approved for use in the United States, are reviewed in depth with reference to dose ranges, side effects, and convenience. Data regarding increases in bone mineral density (BMD) produced by each agent are presented. Specifically, the range of increases in BMD induced by ERT and salmon calcitonin are comparable. Given the substantial public health consequences of postmenopausal osteoporosis and osteoporotic fractures, the primary care physician is increasingly faced with the need to educated and recruit postmenopausal patients to appropriate therapy with the optimal agent for that particular patient. In the many patients who are unable or unwilling to accept, initiate, and comply with prescribed ERT, alternative therapeutic options are necessary Based on the established safety profile of salmon calcitonin, ease of administration, an uncomplicated dosing regimen, no reported drug interactions, and the lack of uterine bleeding associated with ERT or gastrointestinal adverse effects of other agents used to treat osteoporosis, salmon calcitonin nasal spray is an appropriate alternative approach for the treatment of postmenopausal bone loss.

Effects of hormone replacement therapy on cancellous bone microstructure in postmenopausal women

Menopausal bone loss is associated with disruption of cancellous bone architecture which has adverse mechanical effects and is believed to be irreversible. The aim of this study was to examine the effects of long-term hormone replacement therapy on cancellous bone structure in women with postmenopausal osteoporosis. Iliac crest biopsies from 22 women with osteopenia or osteoporosis were obtained before and after hormone replacement therapy (mean duration 23.5 months). Cancellous bone architecture was assessed by strut analysis, trabecular bone pattern factor, and marrow star volume. Post-treatment biopsies showed no significant changes in any of the structural indices assessed. Our results suggest that hormone replacement therapy preserves existing cancellous bone structure but provide no evidence that this treatment is able to reverse structural disruption in women with postmenopausal osteopenia or osteoporosis.

Osteoporosis prevention clinical study program

OBJECTIVES

Oestrogens are widely believed to be effective against postmenopausal osteoporosis. However there are some outstanding questions which still need an answer. For example, the minimal effective dose regimen of oestradiol needs to be established and the relationship between oestradiol levels and efficacy on bone turnover and bone mass needs to be further clarified.

METHODS

Menorest is being tested in the prevention of postmenopausal bone loss. A phase II/III clinical program, that includes two double blind, dose-ranging, placebo-controlled, parallel group, 2-year studies, has started in 58 centers in Europe and South Africa. Four-hundred eighty women will be enrolled in the two studies (201 and 305). The objective of the studies is to evaluate the efficacy of Menorest at different doses and regimens, in the prevention of bone loss in early postmenopausal women. In study 201, the treatment regimen is 'cyclic sequential' (24 days of transdermal oestradiol during a 28-day cycle with progestin taken during the last 14 days of oestrogen administration). In study 305 the treatment regimen is "continuous sequential' (28 days of transdermal oestradiol during, a 28-day cycle with progestin taken during the last 14 days of oestrogen administration). The doses studied are 50, 75, 100 micrograms/day in study 201, and 25, 50, 75 micrograms/day in study 305, (the two studies are otherwise identical). All 'active-dose' treated groups receive dydrogesterone 20 mg/day during the last 14 days of Menorest administration and placebo tablets are given to the placebo patch group. The main entry criteria are natural or surgical menopause, (with hormonal confirmation) from 1 to 6 years, with no contra-indication to HRT and with a bone mineral density (BMD) at the lumbar spine with a T-score between 0 and -3. Women with severe vasomotor symptoms are excluded from the studies. The primary efficacy variable is the mean change from baseline, measured with dual energy X-ray absorptiometry (DXA) at 2 years, in the lumbar spine BMD (L1-L4). Whole body and hip BMD are also evaluated. Markers of bone turnover (bone-specific alkaline phosphatase, osteocalcin and CrossLaps) are monitored throughout the study. Blood samples are drawn on the third day of patch application at certain visits in order to monitor oestradiol levels and establish any potential correlation with activity on bone (BMD, bone markers). Besides routine safety analysis, lipid profile and coagulation factors are also monitored. Special attention is drawn to endometrial safety with endometrial aspiration or trans vaginal sonography (TVS) performed before study start, after 1 year and at 2 years of treatment.

RESULTS

Data presented here refer to 146 patients for whom demographics and clinical data are already available, and to 370 patients for whom baseline DXA data have already been validated. The mean (+/-S.D.) age of the women included in the two studies is 53.4 (+/-3.2) with a menopausal age of 38.3 (+/-19.6) months. None of the women who entered the study had severe postmenopausal symptoms as shown by a mean number of hot flushes of 2.2 (+/-2.6) per day, during the last 14 days before inclusion. The mean (+/-S.D.) lumbar spine (L1-L4) BMD is 0.914 (+/-0.122) g/cm2 which corresponds to a Z-score of -0.26 and a T-score of -1.17. Femoral neck, trochanter and Wards triangle have a BMD which is below the mean of age-matched controls but still within the normal range (Z-scores between 0 and -1). Only the whole body BMD is over the mean of age-matched controls, with a Z-score of 0.32. The in-vivo precision mean (+/-S.D.), was calculated and showed a value of 0.868 (+/-0.872), which can be considered a good performance.

CONCLUSIONS

In summary, the use of one of the most recent techniques to assess the bone mineral content/density together with an accurate quality control program on all the densitometers used in the studies will help to improve the in-vivo BMD precision and therefore mak

An audit of oestradiol levels and implant frequency in women undergoing subcutaneous implant therapy

OBJECTIVES

The aim of the study was to review our long-term use of subcutaneous oestradiol (E2) implant therapy for the treatment of climacteric symptoms in post-menopausal women. On the grounds that the aim is to restore premenopausal serum E2 levels, our declared clinical policy is not to repeat implants even in the presence of symptoms if serum E2 levels are > 400 pmol/l. Therapy was with 50 mg E2 implants inserted subcutaneously in the lower abdominal wall.

DESIGN

All women who had attended the gynaecological/endocrinological clinic who had received subcutaneous E2 implants for the relief of climacteric symptoms between December 1981 and 1992 were included.

RESULTS

Between December 1981 and December 1992, 275 women received a total of 759 50 mg E2 implants. The median length of implant therapy was 34.2 months (range 3.7-109.5 months), and the median number of implants per patient was 4 and ranged from 1 to 13. One hundred and twenty-nine women had more than four implants and their mean recorded serum E2 level was 425 +/- 187 (mean +/- SD) pmol/l; the mean level over the first 24 months of therapy was 408 +/- 157 pmol/l. This was not different from the mean value of the remaining period of therapy (439 +/- 168 pmol/l). Following the second implant there was no significant progressive rise in serum E2 with time and implant number and the mean E2 level per patient was no higher in those patients who received implants more frequently. The mean time between the first two implants was 9.7 +/- 0.4 months and between subsequent ones was 11.7 +/- 0.5 months. After the first two implants there was no progressive change in this interval with time.

CONCLUSION

This study shows that effective, safe and sympathetic management of women with oestrogen deficient symptoms may be achieved by use of two criteria to determine re-treatment; the return of symptoms, and a serum E2 level no higher than 400 pmol/l. Once therapy is established, E2 implants may need to be prescribed only on an annual basis. There appears to be no justification for giving E2 implants more frequently as this policy achieves satisfactory (physiological) premenopausal E2 levels and good symptomatic relief without any evidence for accumulation of E2 or 'tachyphylaxis'.

Testosterone enhances estradiol's effects on postmenopausal bone density and sexuality

To investigate the role of androgens in increasing bone density and improving low libido in postmenopausal women, we have studied the long-term effects of estradiol and testosterone implants on bone mineral density and sexuality in a prospective, 2 year, single-blind randomised trial. Thirty-four postmenopausal volunteers were randomised to treatment with either estradiol implants 50 mg alone (E) or estradiol 50 mg plus testosterone 50 mg (E&T), administered 3-monthly for 2 years. Cyclical oral progestins were taken by those women with an intact uterus. Thirty-two women completed the study. BMD (DEXA) of total body, lumbar vertebrae (L1-L4) and hip area increased significantly in both treatment groups. BMD increased more rapidly in the testosterone treated group at all sites. A substantially greater increase in BMD occurred in the E&T group for total body (P < 0.008), vertebral L1-L4 (P < 0.001) and trochanteric (P < 0.005) measurements. All sexual parameters (Sabbatsberg sexual self-rating scale) improved significantly in both groups. Addition of testosterone resulted in a significantly greater improvement compared to E for sexual activity (P < 0.03), satisfaction (P < 0.03), pleasure (P < 0.01), orgasm (P < 0.035) and relevancy (P < 0.05). Total cholesterol and LDL-cholesterol fell in both groups as did total body fat. Total body fat-free mass (DEXA, anthropometry, impedance) increased in the E&T group only. We concluded that in postmenopausal women, treatment with combined estradiol and testosterone implants was more effective in increasing bone mineral density in the hip and lumbar spine than estradiol implants alone. Significantly greater improvement in sexuality was observed with combined therapy, verifying the therapeutic value of testosterone implants for diminished libido in postmenopausal women. The favourable estrogenic effects on lipids were preserved in women treated with T, in association with beneficial changes in body composition.

The effect of oestradiol implants on regional and total bone mass: a three-year longitudinal study

OBJECTIVE

Although there is evidence from cross-sectional studies that percutaneous oestrogen administration protects against menopausal bone loss, few longitudinal data are available. We have examined the effect of 3 years' treatment with percutaneous oestradiol on total body calcium, spinal trabecular bone mineral density and radial bone mineral content in post-menopausal women.

DESIGN AND PATIENTS

Twenty-nine post-menopausal women, aged 37-55 years, who had undergone hysterectomy and had experienced the onset of menopausal symptoms within the previous 2 years, were studied before and for 3 years during hormone replacement with oestradiol implants, given at approximately 6-monthly intervals.

MEASUREMENTS

Total body calcium was measured by prompt gamma neutron activation analysis, spinal trabecular bone mineral density by quantitative computed tomography and radial bone mineral content by single-photon absorptiometry.

RESULTS

There was a significant increase in the mean total body calcium, spinal trabecular bone mineral density and radial bone mineral content over the 3 years of the study. The mean (+/- SEM) percentage change per annum was +2.4% (+/- 0.8) for total body calcium (P < 0.01), +3.3% (+/- 0.6) for spinal trabecular bone mineral density (P < 0.001) and +1.2% (+/- 0.6) for radial bone mineral content (P < 0.05).

CONCLUSIONS

Percutaneous oestradiol replacement therapy prevents menopausal bone loss and is associated with a sustained and significant increase in total body calcium, spinal trabecular bone mineral density and radial bone mineral content over a 3-year treatment period. Oestradiol implants thus have skeletal effects comparable to those of oral or transdermal oestrogens.

Sustained-release subdermal estradiol implants: a new alternative in estrogen replacement therapy

OBJECTIVE

This trial was a therapeutic and pharmacokinetic dose-finding study with subdermal implants that showed a constant in vitro daily release rate of estradiol. The aim was to find the daily release rate of estradiol that produces serum estradiol concentrations comparable with those obtained with transdermal estradiol at 0.05 mg/day.

STUDY DESIGN

The study was an open crossover comparison of transdermal and subcutaneous delivery systems. Thirty-six postmenopausal (serum follicle-stimulating hormone concentration > 30 IU/L before commencing the study) were treated with transdermal estradiol for 4 weeks. Immediately after this transdermal estradiol delivery was replaced by either one or three estradiol implants. The serum concentrations of estrone, estradiol, follicle-stimulating hormone, and sex hormone-binding globulin were followed up for 8 weeks on implant therapy and compared with those during transdermal estrogen administration. To oppose the estrogen effect on the endometrium, each patient received an intrauterine device releasing a progestin, levonorgestrel.

RESULTS

The serum estradiol concentrations achieved with three implants were comparable with those during transdermal administration of estradiol at 0.05 mg/day. Suppression of follicle-stimulating hormone was also better maintained with three implants compared with one.

CONCLUSIONS

This study shows that constant release profiles can be achieved with nonbiodegradable estradiol implants. The results suggest that a single application should give sufficient estrogen substitution for more than a year.

A clinical trial on the effects of a combination of elcatonin (carbocalcitonin) and conjugated estrogens on vertebral bone mass in early postmenopausal women

The study was carried out to determine the effect of a combination regimen of a small dose of calcitonin added to conjugated estrogens with medroxyprogesterone acetate on vertebral bone mass in early postmenopausal women. Comparisons were made with groups of women on calcitonin alone, on conjugated estrogens with medroxyprogesterone acetate alone, or on no treatment. The study was carried out over a 2-year period. The results of the study suggest that the combined regimen of calcitonin and estrogens increased vertebral bone mass in early postmenopausal women to a greater extent than calcitonin alone or estrogen alone. Increases in vertebral bone mass of 11.2% after 1 year and 9.2% after 2 years were demonstrated using the combined regimen. Both estrogens alone and calcitonin alone were, however, very effective in preventing rapid bone loss in the postmenopausal women studied.

Maintained bone density at advanced ages after long term treatment with low dose oestradiol implants

OBJECTIVE

To investigate whether the bone preserving effect of low dose oestrogen replacement therapy (20 mg oestradiol implanted subcutaneously every six months) persists during continuous long term treatment through advanced ages.

DESIGN

Cross sectional clinical study of postmenopausal women treated with oestradiol implants as compared with nonusers matched for age.

SETTING

Outpatient research unit at a university hospital.

SUBJECTS

Thirty-five women with a mean age of 67 years (range 47-83 years) at the time of investigation who, after a prior hysterectomy, had been treated with oestradiol implants for climacteric symptoms for a mean period of 16 years (range 5.5-31 years). The results were compared with those in women matched for age and without any diseases or medications known to affect the bone metabolism.

MAIN OUTCOME MEASURES

Bone mineral densities (BMD) in the distal forearm, vertebrae and hip analysed by study group, age and duration of treatment.

RESULTS

Implant users had a median serum oestradiol concentration in the luteal range, 313 (range 126-1711) pmol/l, and premenopausal levels of follicle stimulating hormone (FSH). All women except one who were given the standard dose at the standard intervals had serum oestradiol levels below 650 pmol/l. Compared with nonusers, women treated with oestradiol implants had 20 to 25% higher BMD at all measurement sites: distal radius (P < 0.0001), lumbar vertebrae (P < 0.0002) and femoral neck (P < 0.0001). These differences also remained after adjustment for potential confounders (height, age at menarche, parity, smoking habits, physical exercise and education) (P < or = 0.01 at all sites). In a multiple regression analysis the negative effect of advancing age was more than compensated by the positive effect of increasing treatment duration with a higher BMD at all measurement sites in women with a longer as compared with shorter, duration of treatment; the regression coefficients were significant (P < 0.05) in the spine and hip measurements.

CONCLUSIONS

Continuous long term treatment with low dose oestradiol implants yielding physiological levels of serum oestradiol preserves both compact and cancellous bone and the effect seems to persist into advanced ages without any inevitable age related bone loss.

Postmenopausal oestrogen replacement therapy with subcutaneous oestradiol implants

Ten postmenopausal patients were treated by means of subcutaneous oestradiol-releasing silastic implants. Half of the patients received 3 implants, each containing 12 mg oestradiol valerate (E2V), while the other half received 4 implants, each containing 27 mg oestradiol benzoate (E2B). Progestogen was added to the treatment for 14 days, 6 weeks after implant insertion and every fourth week thereafter. Serum levels of oestrone (E1), oestradiol (E2), follicle-stimulating hormone (FSH) and luteinizing hormone (LH) were followed up. The effects on endometrial thickness, uterine volume and breast tissue were evaluated by ultrasound, mammography also being used for breast examination. The follow-up period was 24 weeks, but the implants were not removed until the climacteric symptoms reappeared. E1 and E2 levels remained higher and gonadotrophin levels lower than the pretreatment values during the 24-week follow-up period. Oestrogen effects were seen in both the uterus and the breasts. Both types of implant were effective in relieving climacteric symptoms. The mean time for symptom return was 10 months (range 6-18 months) in the E2V group and 8 months (range 4-12 months) in the E2B group. Our results indicate that nonbiodegradable controlled-release oestrogen implants offer a safe, effective, convenient and well-accepted alternative means of administering oestrogen replacement therapy.

The chemoprevention of breast cancer by reducing sex steroid exposure: perspectives from epidemiology

Mitogenesis is a major driving force in neoplastic development. Blocking the effect of breast cell mitogens by reducing the actual exposure of the breast to these mitogens is an obvious strategy for breast cancer prevention. The ovarian hormones, estrogens and progesterone, are major effective (direct or indirect) breast cell mitogens. A woman's exposure to ovarian estrogens and progesterone is drastically reduced by the use of combination-type oral contraceptives (COCs), but the synthetic estrogen and progestogen in the COCs effectively replace ovarian estrogens and progesterone, so that breast cell exposure to these hormones is not decreased. Doses of estrogen and progestogen in modern COCs are close to the minimum attainable while still retaining both contraceptive efficacy and ovarian suppression (so that endogenous estrogen and progesterone do not add to the dose of estrogen and progestogen from the COC). Considerably lower effective breast cell exposure to estrogen and progestogen can, however, be achieved by using a gonadotropin-releasing hormone agonist (GnRHA) to suppress ovarian function and compensate for the resulting hypoestrogenemia with low-dose hormone replacement therapy. Compared to modern COCs, estrogen exposure can be reduced by approximately 60%, and progestogen dose by more than 80%. Such a contraceptive is predicted to reduce lifetime breast cancer risk by more than 50% if used for 10 years. The possibility that a practical contraceptive could achieve such a major benefit is shown by the dramatic decline in the incidence of both ovarian and endometrial cancer in young women in the U.S. over the last 3 decades--a direct result of COC use.

Increase in bone mass after one year of percutaneous oestradiol and testosterone implants in post-menopausal women who have previously received long-term oral oestrogens

OBJECTIVE

To determine the effect on the bone density of the skeleton after changing from oral oestrogen to subcutaneous oestradiol and testosterone replacement.

DESIGN

Prospective non-randomized single centre study.

SUBJECTS

Twenty women who were receiving long-term oral oestrogen replacement. Ten changed to oestradiol and testosterone implants; the remaining ten continued with oral oestrogens.

MAIN OUTCOME MEASURES

Bone density was measured using dual photon absorptiometry at the lumbar spine and neck of femur at the start of the study and after one year.

RESULTS

The bone density increased significantly by 5.7% at the spine and by 5.2% at the neck of femur in those women who changed to implant therapy but remained unchanged in those women who continued with oral therapy.

CONCLUSION

Subcutaneous oestradiol and testosterone implants will result in an increase in bone mass even after many years of oral oestrogen replacement therapy.

25 mg oestradiol implants--the dosage of first choice for subcutaneous oestrogen replacement therapy?

OBJECTIVE

To assess the oestrogen concentrations and symptom relief obtained with 25 mg oestradiol implants.

DESIGN

Open, observational study.

SUBJECTS

Twelve symptomatic, post-menopausal women seen in a designated menopause clinic.

INTERVENTION

A 25 mg oestradiol pellet was inserted subcutaneously, blood samples were obtained before implantation and at regular intervals (2-4 weeks) until symptoms refused as hypoestrogenaemia developed.

MAIN OUTCOME MEASURES

Change in symptom score following implant treatment. Concentrations of oestrogens and their metabolites before and during low dose subcutaneous oestradiol therapy.

RESULTS

Ten of the 12 women had excellent symptom relief, associated with oestradiol concentrations in the follicular range for between 28 and 35 weeks. The ratio of circulating oestrogen metabolites remained physiological, despite the oestradiol concentrations being substantially higher on treatment.

CONCLUSIONS

We suggest that 25 mg pellets should be used as the initial dose for subcutaneous oestrogen treatment, and a combination of return of symptoms and weeks since insertion used to judge the timing of reimplantation.

Effects of physical activity on some components of the skeletal system

Sporting activities impose on the skeletal system forces of a high intensity and frequency. Ligaments, bone and tendons behave in a time-dependent load-extension fashion, and it is important for both scientists and clinicians to consider, for example, the alterations in failure properties shown by ligaments, tendons and bone at different rates of deformation. Whether the ability of the skeletal system to withstand stress can be improved with appropriate training is still controversial. The effects of physical exercise depend on the modality, intensity and duration with which the exercise itself is performed. Moreover, genetic factors, also influencing growth and hormonal status, may exert a significant influence on the response of a given tissue to an external load. Overloading may cause a lesion, and this may decrease or annihilate performance capability. The skeletal system may not be resistant enough, and so it may prove limiting to intensive physical activity. In vitro studies on resistance of a single tissue have not taken into consideration the specific resistance of that structure in vivo, and the results so obtained cannot be readily extrapolated to sporting activities, as in vivo muscles, joints, tendons, ligaments and cartilage act as one. This article reviews some of the possible beneficial and detrimental effects of intense exercise on various components of the skeletal system, focusing on its ability to withstand and adapt to stresses and allow maximal performance.

Effect of 17 beta-oestradiol on lymphocyte subpopulations, delayed cutaneous hypersensitivity responses and mixed lymphocyte reactions in post-menopausal women

High-dose steroids are known to be potent modulators of the immune response. We accordingly investigated the effect of therapeutic doses of 17 beta-oestradiol (E2) on cellular immune responses in post-menopausal women. Fifteen (15) healthy women who had undergone a natural menopause were treated with E2 in the form of 100 mg estraderm patches applied twice weekly for 3 out of every 4 weeks over a 3-month period, followed by combined oestrogen and progestogen formulations as long-term therapy. Blood samples were taken on two occasions prior to treatment and at weeks 1, 3, 4, 7, 9, 12 and 24 after commencing therapy. Lymphocyte subsets (CD2, CD4, CD8, CD19, HLA-DR and NK) were studied in each blood sample using a monoclonal antibody kit and a two-colour fluorescence flow-cytometer. One-way mixed lymphocyte reactions (MLRs) were performed using the same stimulator throughout. Delayed hypersensitivity skin tests (DHTs) were carried out twice before treatment and at weeks 3, 4, 12 and 24 using Multitest 7-antigen kits (Institut Mérieux). Lymphocyte subsets did not change significantly with treatment, but both the MLRs and the DHTs were significantly depressed, maximally so by the third week of treatment. We conclude that therapeutic doses of E2 modulate certain immune responses. The significance of this is discussed in the light of the increasing use of long-term oestrogen replacement therapy.

The prevention of breast cancer through reduced ovarian steroid exposure

Analysis of epidemiologic data on cancers of the breast, ovary and endometrium; the effects of endogenous hormones on cell proliferation; and current carcinogenesis concepts, suggest that hormonal contraceptives can be developed that will reduce lifetime risk of all 3 cancers. The 'unopposed-estrogen hypothesis' accounts for endometrial cancer risk factors. Ovarian cancer risk is closely related to the total frequency of ovulation. The risk of breast cancer can be explained by an 'estrogen-plus-progestogen hypothesis'. On the basis of this analysis an hormonal contraceptive regimen has been developed consisting of a gonadotropin-releasing hormone agonist (GnRHA) plus continuous low-dose add-back estrogen and a short course of progestogen every fourth month. The total dose of add-back estrogen is estimated to be approximately 38% that in present-day low-dose combination-type oral contraceptives (COCs). The total dose of progestogen is approximately 15% that in COCs. This regimen prevents ovulation and should thus reduce ovarian cancer risk. It also reduces the exposure of the endometrium to unopposed estrogen, and the exposure of the breast to estrogen-plus-progestogen. It is estimated that use of such a regimen for 10 years will only reduce lifetime risk of endometrial cancer by one-sixth, but lifetime risk of ovarian cancer is estimated to be reduced by two-thirds, and lifetime risk of breast cancer is estimated to be reduced by one-half.

GnRH agonists as contraceptive agents: predicted significantly reduced risk of breast cancer

Gonadotrophin-releasing hormone agonists (GnRHAs) were investigated as contraceptive agents from the late 1970's to the mid-1980's. They were abandoned as they appeared to offer no advantage over conventional combination-type oral contraceptives (COCs). This conclusion appears to be incorrect. We propose here a contraceptive regimen of a depot formulation of a GnRHA plus add-back estrogen and intermittent progestogen. The dose of add-back sex-steroids is substantially less than that in COCs; this reduction in sex-steroids should lead to a major reduction in lifetime breast cancer occurrence.

The relationship between plasma estradiol and the increase in bone density in postmenopausal women after treatment with subcutaneous hormone implants

Twenty-three postmenopausal women with a median of 2 years past menopause (range, 1 to 12 years) and a median age of 52 years (range, 39 to 62 years) were recruited to participate in a longitudinal study designed to investigate the factors that influence the increase in bone density with subcutaneous estradiol and testosterone implants. All women received 75 mg of estradiol with 100 mg testosterone subcutaneously. Bone density was measured at the spine and hip by dual-photon absorptiometry before therapy and after 1 year of subcutaneous hormonal therapy. The mean pretreatment bone density at the lumber vertebrae and neck of the femur was 0.84 grams of hydroxyapatite per square centimeter (SD, 0.11) and 0.73 grams of hydroxyapatite per square centimeter (SD, 0.10), respectively. The bone density at both sites increased with values of 0.91 grams of hydroxyapatite per square centimeter (SD, 0.11) and 0.75 grams of hydroxyapatite per square centimeter (SD, 0.11), respectively. These values represent an increase of 8.3% (p less than 0.0001) at the spine and 2.8% (p less than 0.01) at the neck of the femur. The plasma estradiol level increased from a median of 80.5 pmol/L to 453 pmol/L (p less than 0.001). The percentage increase of vertebral bone density was not related to age, number of years past the menopause, pretreatment bone density, or serum testosterone levels, but a significant correlation was found between the percentage increase in bone density at the spine and the serum estradiol level (p less than 0.02, r = 0.45).

Hormone implants and tachyphylaxis

The serum oestradiol levels of 1388 women treated with hormone implants at a menopause clinic were reviewed in 1988. Thirty-eight (3%) were found to be above 1750 pmol/l. Of these 38 women with supraphysiological oestradiol levels 23 had started therapy for menopausal symptoms and 15 for the premenstrual syndrome (PMS). Of the 23 women treated for menopausal symptoms 11 had a history of psychiatric referral for depression and nine had undergone a surgical menopause. Nine of the 15 women with PMS had a history of psychiatric referral for depressive symptoms. We conclude that the women who attain supraphysiological levels of oestradiol on implant therapy have a high frequency of psychopathology or surgical menopause and may require higher oestradiol levels for adequate control of symptoms.

Prolonged endometrial stimulation associated with oestradiol implants

OBJECTIVE

To provide information on endometrial stimulation after discontinuation of treatment with oestradiol implants.

DESIGN

Long term follow up of withdrawal bleeding patterns in women taking progestogens cyclically every month after oestradiol implant treatment was ended.

SETTING

Specialist menopause clinic.

SUBJECTS

10 Postmenopausal patients (at least 12 months' amenorrhoea after the last spontaneous period) who were treated with oestradiol implants for typical symptoms of oestrogen deficiency. The oestradiol dose was 50 mg, reimplantation occurring roughly every six months. Patients subsequently either needed to discontinue the hormone treatment for medical reasons or expressed a desire to stop treatment.

MAIN OUTCOME MEASURE

Duration of endometrial stimulation--defined as the presence of withdrawal bleeding in response to progestogen given cyclically--after insertion of the last oestradiol implant.

RESULTS

Four patients eventually stopped bleeding, their mean duration of bleeding being 35 months (range 27-43 months). One patient required hysterectomy 26 months after the last implantation because of persistent irregular bleeding despite treatment with high doses of progestogen. Three patients bled for 22, 30, and 36 months and then restarted oestrogen treatment because symptoms returned. The last two patients subsequently continued to bleed 12 and 21 months after the last implantation.

CONCLUSIONS

The duration of endometrial stimulation after implantation can be prolonged, up to 43 months. Insertion of oestradiol implants can carry a long term commitment to the cyclical administration of progestogen and regular withdrawal bleeding if endometrial hyperplasia and carcinoma are to be avoided.

Impact of bone mineral measurements on osteoporosis

Dual photon absorptiometry enables measurement of bone mineral to be carried out at the clinically relevant sites of the spine and femur. Few would argue that it provides a powerful research tool, but defining its role in clinical practice has been somewhat more difficult. With the advent of X-ray based systems, studies can be rapidly carried out with improved precision, which has led to increased clinical interest. It is probable that this technology will be incorporated into routine use in the near future. In the present review we have addressed the role of dual photon absorptiometry in areas pertinent to osteoporosis and the direction in which recent developments are leading with regard to future research.