Minimal levels of serum estradiol prevent postmenopausal bone loss

Comparative estrogen exposure from compounded transdermal estradiol creams and Food and Drug Administration-approved transdermal estradiol gels and patches

OBJECTIVE

The aim of this study was to evaluate the amount of estrogen exposure associated with the use of compounded transdermal estradiol (E2) creams and compare it with estrogen exposure associated with the use of Food and Drug Administration (FDA)-approved transdermal E2 patches and gels.

METHODS

This was a retrospective cohort study that used clinical laboratory data collected from January 1, 2016, to December 31, 2019. Participants were first divided into three groups: postmenopausal women on no menopausal hormone therapy (n = 8,720); postmenopausal women using either a transdermal E2 patch, gel, or cream (n = 1,062); and premenopausal women on no hormonal therapy (n = 16,308). The postmenopausal menopausal hormone therapy group was further subdivided by formulation (patch [n = 777], gel [n = 132], or cream [n = 153]) and dose range (low, mid, or high). The Jonckheere-Terpstra trend test was used to determine if there was a dose-dependent trend in urinary E2 with increasing dose of compounded E2 cream (dose categories for E2 cream subanalysis, <0.5 mg [n = 49], ≥0.5-≤1.0 mg [n = 50], ≥1.0-≤1.5 mg [n = 58], and >1.5-≤3.0 mg [n = 46]). Urinary E2 and other characteristics were compared across formulations (within each dose range) using Kruskal-Wallis one-way analysis of variance.

RESULTS

A dose-dependent, ordered trend existed for urinary E2 with increasing doses of compounded E2 cream (urinary E2 medians [ng/mg-Cr], 0.80 for <0.5 mg, 0.73 for ≥0.5-≤1.0 mg, 1.39 for ≥1.0-≤1.5 mg, and 1.74 for >1.5-≤3.0 mg; Jonckheere-Terpstra trend test, P < 0.001). Significant differences in urinary E2 concentrations were observed in all three dose ranges (Kruskal-Wallis one-way analysis of variance, P = 0.013 for low dose, P < 0.001 for mid dose, P = 0.009 for high dose). Comparison of E2 concentrations of compounded creams to E2 concentrations obtained with similar doses of FDA-approved patches and gels showed that the creams had significantly lower values than the patches and gels.

CONCLUSIONS

Estrogen exposure from compounded transdermal E2 creams increases in a dose-dependent manner; however, the amount of estrogen exposure associated with compounded creams is significantly lower than estrogen exposure associated with FDA-approved transdermal E2 patches and gels. Clinicians should be aware of the direction and magnitude of these potential differences in estrogen exposure when encountering women who have either previously used or are currently using compounded E2 creams.

Assessment of estrogen exposure from transdermal estradiol gel therapy with a dried urine assay

Transdermal estradiol gel is a commonly used menopausal hormone therapy. In research studies investigating the pharmacokinetics and clinical utility of transdermal estradiol gels, serum is often used to measure estradiol levels. Serum results only represent a moment in time during phlebotomy and thus provide little information and allow for limited inference unless serial measurements are performed. In contrast, dried urine may provide a representation of serum estradiol levels over a longer period of time, while also being non-invasive and easier to collect. The primary aim of this study was to evaluate a dried urine method to determine if it may be a viable option for evaluating estrogen exposure resulting from transdermal estradiol gel use. A secondary aim was to explore differences in the urinary estrogen profiles of premenopausal women on no therapy and postmenopausal women who were either on transdermal estradiol gel therapy or no therapy at all. The results of this study demonstrated that the expected dose-proportional changes in estrogen exposure can be observed in the urinary estrogen profile using a GC-MS/MS dried urine assay. The GC-MS/MS assay also showed the differences in the urinary estrogen profiles of premenopausal women, postmenopausal women on estrogen replacement therapy, and postmenopausal women on no therapy.

Management of postmenopausal women: Collège National des Gynécologues et Obstétriciens Français (CNGOF) and Groupe d'Etude sur la Ménopause et le Vieillissement (GEMVi) Clinical Practice Guidelines

AIM

The aim of these recommendations is to set forth an individualized approach to the management of early postmenopausal women (i.e., within the first 10 years after natural menopause) covering all aspects of lifestyle and therapeutic management, with or without menopause hormone therapy (MHT).

MATERIALS AND METHODS

Literature review and consensus of French expert opinion. Recommendations were graded according to the HAS methodology and levels of evidence derived from the international literature, except when there was no good-quality evidence.

SUMMARY RECOMMENDATIONS

The beginning of menopause is an ideal time for each woman to evaluate her health status by assessing her bone, cardiovascular, and cancer-related risk factors that may be amplified by postmenopausal estrogen deficiency and by reviewing her lifestyle habits. Improving lifestyle, including nutrition and physical activity, and avoiding risk factors (notably smoking), should be recommended to all women. MHT remains the most effective treatment for vasomotor symptoms but it could be also recommended as first-line treatment for the prevention of osteoporosis in early postmenopausal women at low to moderate risk for fracture. The risks of MHT differ depending on its type, dose, duration of use, route of administration, timing of initiation, and whether a progestogen is used. There is reasonable evidence that using transdermal estradiol in association with micronized progesterone or dydrogesterone may limit both the venous thromboembolic risk associated with oral estrogens and the risk of breast cancer associated with synthetic progestins. Treatment should be individualized to each woman, by using the best available evidence to maximize benefits and minimize risks, with periodic reevaluation of its benefit-risk balance. For bothersome genitourinary syndrome of menopause (GSM) symptoms, vaginal treatment with lubricants and moisturizers is recommended as first-line treatment together with low-dose vaginal estrogen therapy, depending on the clinical course. No recommendation of an optimal duration of MHT can be made, but it must take into consideration the initial indication for MHT as well as each woman's benefit-risk balance. Management of gynecological side-effects of MHT is also examined. These recommendations are endorsed by the Groupe d'Etude sur la Ménopause et le Vieillissement hormonal (GEMVI) and the Collège National des Gynécologues-Obstétriciens Français (CNGOF).

Unstimulated Salivary Estrogen in Postmenopausal Women With and Without Oral Dryness: A Prospective Study

Objective:

This study aimed to compare the unstimulated salivary estrogen levels in postmenopausal women with and without oral dryness.

Methodology:

A study was carried out on 70 selected postmenopausal women, out of which 35 were in the case group and 35 were in the control group. A questionnaire related to oral dryness was given to all the patients to evaluate their response to oral dryness. Patients were asked to spit in a plastic container, and their unstimulated saliva samples were obtained and analyzed for estimation of salivary estrogen levels by ELISA technique. After analyzing the results of salivary estrogen levels, the patients in the case group with low levels of estrogen were subjected to HRT under the guidance of a gynecologist. The patients were followed after 3 months of therapy for their response to oral dryness by the questionnaire, and salivary estrogen levels were again reevaluated after the therapy. The statistical analysis was carried out using Statistical Package for Social Sciences (SPSS Inc, Chicago, IL, version 15.0 for windows). The Pearson’s correlation and Student’s unpaired t-test were used for comparisons.

Results:

Before hormone replacement therapy, the mean estrogen level of the case group was 1.0031, and the mean estrogen level of the control group was 4.0080 pg/ml. This suggested that the reduced levels of estrogen hormone after menopause were associated with the complaint of oral dryness in these females. The mean salivary estrogen levels in the case group after HRT were more than the levels before HRT.

Conclusion:

Estrogen levels were reduced in patients with oral dryness. Further, the patients receiving HRT showed significant improvement in symptoms of oral dryness.

[Menopause, menopause hormone therapy and osteoporosis. Postmenopausal women management: CNGOF and GEMVi clinical practice guidelines]

Postmenopausal osteoporosis is a frequent clinical condition, which affects nearly 1 in 3 women. Estrogen deficiency leads to rapid bone loss, which is maximal within the first years after the menopause transition and can be prevented by menopause hormone therapy (MHT). Assessment of the individual risk of osteoporosis is primarily based on the measurement of bone mineral density (BMD) at the spine and femur by DXA. Clinical risk factors (CRFs) for fractures taken either alone or in combination in the FRAX score were shown not to reliably predict fractures and/or osteoporosis (as defined by a T-score<-2.5) in early postmenopausal women. If DXA measurement is indicated in all women with CRFs for fractures, it can be proposed on a case-by-case basis, when knowledge of BMD is likely to condition the management of women at the beginning of menopause, particularly the benefit-risk balance of MHT. MHT prevents both bone loss and degradation of the bone microarchitecture in early menopause. It significantly reduces the risk of fracture at all bone sites by 20 to 40% regardless of basal level of risk with an estrogen-dependent dose-effect. Given the inter-individual variability in bone response, individual monitoring of the bone effect of MHT is warranted when prescribed for the prevention of osteoporosis. This monitoring is based on repeated measurement of lumbar and femoral BMD (on the same DXA measurement system) after 2years of MHT, the response criterion being no significant bone loss. Discontinuation of treatment is associated with a resumption of transient bone loss although there is a large variability in the rate of bone loss among women. Basically, there is a return to the level of fracture risk comparable to that of in untreated woman of the same age within 2 to 5years. Therefore, when MHT is prescribed for the prevention of osteoporosis in women with an increased risk at the beginning of menopause, measurement of BMD is recommended when MHT is stopped in order to consider further management of the risk of fracture whenever necessary (with possibly another anti-osteoporotic treatment).

Bone turnover markers in women participating in a dose-finding trial of a contraceptive vaginal ring releasing Nestorone and estradiol

OBJECTIVE

To evaluate changes in the bone turnover markers CTx and P1NP during 6 months' use of novel continuous contraceptive vaginal rings delivering Nestorone (NES) 200 mcg/day and three doses of estradiol (E2) (10, 20, and 40 mcg/day).

STUDY DESIGN

This randomized trial enrolled 189 women who used two consecutive vaginal rings over 180 days. Frequent blood sampling permitted analysis of NES, E2, CTx and P1NP concentrations. The bone-turnover marker analyses included only women with complete sampling and excluded women with characteristics that might interfere with accurate measurement of bone markers such as afternoon sampling, poor ring compliance or recent pregnancy. We evaluated the change from baseline to 6 months in CTx and P1NP, stratified by ring dose and by average circulating E2 concentrations.

RESULTS

One hundred fifty-one women completed the study, and 82 women had complete data available for the bone marker analyses; the three dosage groups were balanced with regard to baseline characteristics. E2 concentrations remained low throughout treatment, regardless of which dose ring the participant used. Individual CTx changes from baseline averaged 27±56% (p<.01). Similarly, individual P1NP changes averaged 11±33% (p=.04). These increases were within the premenopausal reference ranges, and unrelated to treatment dose or to circulating E2 concentrations.

CONCLUSIONS

The low E2 dose of these rings was associated with low E2 concentrations and modest increases in serum bone turnover makers. Because we have only 6-month bone turnover markers and no direct evidence of bone loss or bone density change, these results must be interpreted with caution.

IMPLICATIONS

Nestorone, a 19-norprogesterone derivative, leads to complete ovarian suppression, which should yield excellent contraceptive effectiveness. To prevent potential adverse effects on bone, the NES contraceptive ring should be combined with higher doses of E2 than were assessed in this study.

Levels of serum estradiol and lifestyle factors related with bone mineral density in premenopausal Mexican women: a cross-sectional analysis

BACKGROUND

Many factors, such as heredity, ethnicity, nutrition and other lifestyle factors, have been related to bone mineral density in postmenopausal women. Additionally, bone mass has been significantly associated with decreased estrogen levels. However, fewstudies have been conducted on premenopausal women. The present study was designed to estimate the relationship between low bone mineral density and levels of serum estradiol and lifestyle factors in premenopausal Mexican women.

METHODS

A cross-sectional study was conducted in 270 women between 40 and 48 years of age who participate in the Health Workers Cohort Study. Information on socio-demographic and lifestyle factors were obtained through a self-administered questionnaire. Body mass index and serum estradiol were measured with standard procedures; bone mineral density was assessed using dual-energy X-ray absorptiometry. Multiple linear and logistic regression models were computed to evaluate the relationship between low bone mineral density and levels of serum estradiol and lifestyle factors.

RESULTS

In linear regression analysis levels of estradiol, body mass index, physical activity, and vitamin D intake were positively related to bone mineral density. Age, cigarette smoking and caffeine were inversely associated with BMD. Finally, the odds of low bone mineral density increase significantly when the premenopausal women had low levels of serum estradiol (OR = 4.93, 95 % CI: 2.14, 11.37).

CONCLUSION

These data support that low serum estradiol, advancing age, lower physical activity, lower vitamin D intake, cigarette smoking, and higher amount of caffeine intake are linked to low bone mineral density in premenopausal Mexican women.

Challenges to the measurement of estradiol: an endocrine society position statement

OBJECTIVE

The objective of the study was to evaluate the current state of clinical assays for estradiol in the context of their applications.

PARTICIPANTS

The participants were appointed by the Council of The Endocrine Society and charged with attaining the objective using published data and expert opinion.

EVIDENCE

Data were gathered from published sources via online databases (principally PubMed, Ovid MEDLINE, Google Scholar), and the clinical and laboratory experience of the participants.

CONSENSUS PROCESS

The statement was an effort of the committee and was reviewed by each member. The Clinical Affairs Committee, the Council of The Endocrine Society, and JCEM reviewers reviewed the manuscript and made recommendations.

CONCLUSIONS

The measurement of estradiol in biological fluids is important in human biology from cradle to grave. In addition to its centrality in sexual development, it has significant effects on skin, blood vessels, bone, muscle, coagulation, hepatic cells, adipose tissue, the kidney, the gastrointestinal tract, brain, lung, and pancreas. Alterations in its plasma concentration have been implicated in coronary artery disease, stroke, and breast cancer. Although modern immunoassays and liquid chromatography/tandem mass spectrometry-based methods for estradiol are reasonably well suited to the diagnosis and management of infertility (nonetheless, imprecision and method-to-method differences remain problematic), the very low concentrations that appear to be crucial in nonreproductive tissues are a separate and more difficult issue. Such levels of estradiol are too low to be routinely measured accurately or precisely, and further evolution of analytical methods and the way in which estradiol is standardized is needed.

Response to hormonal treatment of young females with primary or very premature ovarian failure

The aim of this study was to evaluate the impact of hormone treatment (HT) on several endocrinologic, metabolic and bone parameters in young women with primary or very premature ovarian failure. The study included 40 phenotypically females of 14-20 years old with primary or secondary amenorrhoea and female external genitalia. Study subjects were categorised in three groups: Group A included 12 subjects with Turner syndrome, Group B included 19 subjects with Swyer syndrome and Group C included 9 subjects with very premature ovarian failure. HT was administered for 24 months and included conjugated oestrogens and medroxyprogesterone acetate. In all groups, HT provided a beneficial hormonal profile and resulted in safe and adequate serum oestrogens levels. In Group A, no adverse effects on metabolic or coagulation parameters were noted; significant increases in high-density lipoprotein cholesterol (HDL) levels and bone density were observed. Similar positive effects of HT were observed in Group B. Finally, in Group C, no adverse effects of HT were noted, but the favourable increase in HDL was absent; bone density kept significantly increasing until the 12-month evaluation. In conclusion, the administration of HT is remarkably beneficial for young women with primary or very premature ovarian failure.

Estradiol gel

OBJECTIVE

To review the pharmacology, pharmacokinetics, safety, and efficacy of a gel containing estradiol that is applied to the skin.

DESIGN

MEDLINE and EMBASE searches were conducted from 1966 to March 2005. Additional references were identified from bibliographies from selected studies in addition to approved product information.

RESULTS

Estradiol gel is indicated for the relief of moderate to severe vasomotor symptoms in menopausal women, and moderate to severe symptoms of vulvar and vaginal atrophy. Women who are intolerant of the oral route, have had previous hypersensitivity skin reactions, or have had difficulties with adhesive patches are ideal candidates for estradiol gel.

CONCLUSIONS

Estradiol gel can effectively reduce menopause symptoms with minimal side effects. Long-term safety data of estradiol gel are required.

Raloxifene reduces fractures in postmenopausal women with osteoporosis

Recently, selective estrogen receptor modulators have been developed for the management of osteoporosis based on antiosteoclastic properties similar to that of estrogens but with a safety profile including potential benefits on the breast, heart, and cognitive function. Raloxifene, the first selective estrogen receptor modulator to be marketed for the treatment of osteoporosis has shown reduction in spinal fracture risk in patients with low bone mineral density with (48%) or without (35%) prevalent vertebral fracture. Raloxifene also reduces nonvertebral fractures in high risk patients (47%). The decrease in Type I procollagen N-terminal propeptide at 1 year accounts for 28% of the total reduction in vertebral fracture risk. Raloxifene reduced the risk of estrogen receptor-positive invasive breast cancer by 84%. Among subjects with increased cardiovascular risk at baseline, those assigned to raloxifene had a 40% decrease in the risk of cardiovascular events compared with placebo. The definite anti-fracture efficacy of raloxifene at the spine, its plausible effect on non-spine fracture in high-risk patients and its beneficial effect on breast and heart make this compound an interesting approach for women presenting with osteoporosis.

LEVEL OF EVIDENCE

Therapeutic study, level II (lesser quality randomized controlled trial [eg, < 80% followup, no blinding, or improper randomization]). See the Guidelines for Authors for a complete description of the levels of evidence.

Appropriate use of hormones should alleviate concerns of cardiovascular and breast cancer risk

Since the publication of several recent randomized trials in the United States, prescriptions for hormonal therapy have dropped precipitously. This has been due, in large part, to the concerns about the increased risk of cardiovascular (CV) disease and breast cancer among the hormone users. This review takes the perspective that the appropriate use of hormones largely alleviates these concerns. The appropriate use of hormones pertains to treating younger, healthy women who have menopausal symptoms as well as using low-doses of hormones. In the randomized trials, suggesting an increased CV risk, the older women were largely asymptomatic and had other CV risk factors. Data are presented to suggest that there is no increased CV risk with hormonal therapy in younger, healthy women within 5 years of menopause. Moreover, a model is presented to attempt to explain the potential of preventing CV disease when estrogen is begun early, and the relative hazard associated with later use. The risk of breast cancer with hormonal therapy is put into perspective with the realization that this risk is related to hormonal dose and duration of use, and that the absolute risk remains small. Use of progestogens, in particular, appears to enhance this risk. The appropriate use of hormones also pertains to using lower-doses. Here data are presented showing efficacy with lower-doses and improved safety. With the use of lower-doses of estrogens, the progestogen dose, as required in women with a uterus, can be minimized.

The relative effect of endogenous estradiol and androgens on menopausal bone loss: a longitudinal study

OBJECTIVE

The aim of this study was to assess the relative strength of the association of endogenous estradiol and androgens with bone loss at the lumbar spine and femoral neck during the menopausal transition.

DESIGN

A longitudinal study of a population-based cohort of 159 Australian-born women who at baseline had a mean age of 50.0 years (SD=2.4) and had menstruated in the prior 3 months. BMD was measured by dual-energy X-ray absorptiometry at the lumbar spine and femoral neck on up to three occasions.

RESULTS

Of the 159 participants, 50 had two BMD measurements and 109 had a third measure. The mean time between the first and final measures for the whole group was 39 months and at the time of the final measures 49% of the participants had become postmenopausal. The mean percentage change/year in lumbar spine BMD was -0.9% (95% CI, -1.1 to -0.6) and at the femoral neck, -0.5% (95% CI, -0.7 to -0.2). A highly significant association with estradiol at the final time point was found, whereas the contribution of estradiol at baseline was negligible. The variance explained by estradiol levels was 19% and 11% for change in BMD at the LS and FN, respectively. Excluding baseline estradiol values and using the average of change in BMD at the LS and FN, the final regression equation estimated that an estradiol level of 330 pmol/l (95% CI, 274 to 386) and 245 pmol/l (95% CI, 194 to 296) is required for preservation of LS and FN BMD, respectively. A stepwise linear regression model was used to assess the effect of age, BMI, estradiol, testosterone, DHEAS, SHBG, and free testosterone index on changes in BMD and found that only the final estradiol level had a significant association with change in BMD.

CONCLUSION

Endogenous estradiol was the only hormone among those investigated to have a significant effect on bone mineral density during the menopausal transition.

Thoughts on Individualizing Hormone Replacement Therapy Based on the Postmenopausal Health Disparities Study Data

BACKGROUND

This study presents an approach that can be used to address the controversy about the long-term risks and benefits of hormone replacement therapy (HRT).

METHODS

Categories of estradiol (E(2)) levels based on the mean and standard deviation (SD) in postmenopausal women not treated with HRT were created. E(2) levels achieved in women treated with oral or patch replacement therapy were examined. In the application of this method, data from the Postmenopausal Health Disparities Study were used because identical E(2) assay methods were used for all postmenopausal women in the study population.

RESULTS

The findings demonstrated that approximately 42% of HRT-treated women had E(2) levels less than the mean E(2) level plus 1 SD in the controls (37 pg/ml). In contrast, approximately 11% had E(2) levels greater than the mean E(2) level plus 6 SD in the controls (126 pg/ml). Menopausal vasomotor and vaginal symptoms decreased ( p < 0.06) in increasing control-based E(2) categories. Levels of both follicle-stimulating hormone (FSH) and luteinizing hormone (LH) were significantly correlated with the E(2) control-based categories (both p = 0.000). When hormone variables and other variables (e.g., moderate alcoholic beverage consumption and bilateral ovariectomy) known to be determinants of E(2) levels in postmenopausal women not treated with HRT were included in the model for oral or patch HRT-treated women, 51.1% of the variability in the control-based E(2) categories was explained when menopause duration, use of oral as opposed to patch therapy, body mass index (BMI), scores for medical compliance, and being white entered the equation as statistically significant predictors.

CONCLUSIONS

First, there is substantial variability in E(2) concentrations achieved with conventional oral and patch HRT. Second, various factors that are statistically significant predictors of response categories have been identified. Third, race/ethnic group plays a role in the response to HRT. Finally, the demonstration of variable responses to HRT and the application of the categorization paradigm presented will be useful in resolving the controversy about the risks and benefits of conventional HRT.

A longitudinal study of the effect of subcutaneous estrogen replacement on bone in young women with Turner's syndrome

It is desirable that young women with primary ovarian failure achieve normal peak bone mass to reduce the subsequent risk of osteoporosis, and that there are management strategies to replace bone that is already lost. While estrogen (E2) is generally considered to prevent bone loss by suppressing bone resorption, it is now recognized that estrogen also exerts an anabolic effect on the human skeleton. In this study, we tested whether estrogen could increase bone mass in women with primary ovarian failure. We studied the mechanism underlying this by analyzing biochemical markers of bone turnover and iliac crest biopsy specimens obtained before and 3 years after E2 replacement. Twenty-one women with Turner's syndrome, aged 20-40 years, were studied. The T scores of bone mineral density at lumbar spine and proximal femur at baseline were -1.4 and -1.1, respectively. Hormone replacement was given as subcutaneous E2 implants (50 mg every 6 months) with oral medroxy progesterone. Serum E2 levels increased incrementally from 87.5 pM at baseline to 323, 506, 647, and 713 pM after 6 months and 1, 2, and 3 years of hormone replacement therapy (HRT), respectively. The bone mineral density at the lumbar spine and proximal femur increased after 3 years to T scores of -0.2 and -0.4, respectively. The cancellous bone volume increased significantly from 13.4% to 18.8%. There was a decrease in activation frequency, but the active formation period was increased by HRT. There was a significant increase in the wall thickness from 33.4 microm at baseline to 40.9 microm after 3 years of HRT, reflecting an increase in bone formed at individual remodeling units. Although there was an early increase in biochemical markers of bone formation, these declined thereafter. Our results show that estrogen is capable of exerting an anabolic effect in the skeleton of young women with Turner's syndrome and low bone mass.

Basal plasma hormone levels in depressed perimenopausal women

BACKGROUND

An association between abnormal changes in reproductive endocrine function during the perimenopause and the onset of depression in some women has been suggested but remains controversial.

METHODS

We examined basal plasma hormone levels in two samples of women with well characterized, first onset depression (major or minor) during the perimenopause and matched comparison groups of asymptomatic women. Results were compared by analysis of variance.

RESULTS

No significant diagnosis-related differences were observed in plasma hormone measures of the following: follicle stimulating hormone (FSH), luteinizing hormone (LH), estradiol (E2), estrone (E1), total (T) or free testosterone (FT), or the E2/LH ratio. We did identify significantly lower morning plasma dehydroepiandrosterone (DHEA) and its sulphated metabolite DHEA-S (but not cortisol) levels in the depressed women compared to the non-depressed comparison group. Women with hot flushes (regardless of the presence of depression) were significantly older than women without flushes, had significantly higher plasma levels of FT, LH and FSH, and had significantly lower E2/LH ratios.

CONCLUSIONS

Women with first onset depression during the perimenopause are not distinguished from controls on the basis of basal hormone measures of ovarian estrogens, testosterone, or gonadotropins. However, perimenopause-related changes in E2 may interact with low levels of DHEA in some women to increase their vulnerability to develop depression. In contrast to perimenopause-related vasomotor symptoms, depression during the perimenopause is not associated with a simple hormone deficiency state. The relatively low levels of E2 and E1 in the depressed women may have met statistical significance in a much larger and homogenous sample.

Oral hormone replacement therapy: factors that influence the estradiol concentrations achieved in a multiracial study population

The assumption that estradiol (E2) concentrations are reliably increased to therapeutic levels in postmenopausal women receiving hormone replacement therapy (HRT) has not been explicitly tested. Nor have factors that may modulate the E2 levels achieved been evaluated. The author examined E2 concentrations in a multiracial study population of 309 postmenopausal women treated with oral HRT and observed that 51.1% had achieved estradiol levels of at least 45 pg/ml (achievers). The odds of being an achiever were significantly elevated among non-Caucasian women by a HRT dose greater than 0.625 mg, current moderate drinking, and increasing duration of HRT use. The odds were significantly decreased by having a high school education or less and increasing time since last HRT dose. White postmenopausal women had significantly reduced odds of being an achiever, and both a dose of less than 0.625 mg and a dose equal to 0.625 mg significantly reduced the odds of being an achiever. Increasing body mass index and menopause duration were both associated with lower odds. This report demonstrates not only that women treated with HRTdo not all achieve therapeutic levels of estradiol but also that factors can be identified that modulate the E2 concentration achieved in response to HRT administration.

Esterified estrogen therapy in postmenopausal women. Relationships of bone marker changes and plasma estradiol to BMD changes: a two-year study

OBJECTIVE

To determine the relationships among bone mineral density changes, bone marker changes, and plasma estrogens in postmenopausal women receiving estrogen replacement therapy.

DESIGN

A total of 406 postmenopausal women received 1,000 mg calcium and continuous esterified estrogens (0.3 mg, 0.625 mg, or 1.25 mg) or placebo daily for up to 24 months. Bone mineral density and bone marker measurements were determined at 6-month intervals; plasma estrogens were measured in a subset after 12, 18, and 24 months.

RESULTS

Esterified estrogens produced significant increases in bone mineral density (lumbar spine, hip) compared with baseline and placebo at 6, 12, 18, and 24 months. Bone markers decreased from baseline with all esterified estrogen doses relative to placebo. Bone marker changes at 6 months correlated negatively with bone mineral density changes at 24 months (correlation coefficient range = -0.122 to -0.439). The strongest correlation was noted for spine bone mineral density changes and serum osteocalcin. Mean plasma estrogen levels increased with esterified estrogen dose, and bone mineral density changes correlated positively with plasma estrogen levels. Positive bone mineral density changes were noted in treatment groups with plasma estradiol levels at and above 25 pg/mL.

CONCLUSIONS

Esterified estrogens, at doses from 0.3 mg to 1.25 mg/day, unopposed by progestin, increase bone mineral density of the spine and hip in postmenopausal women. These bone mineral density changes correlated significantly with bone marker changes at 6 months and with plasma estrogens at 12, 18, or 24 months. Data variability minimizes the predictive value of the bone marker changes in monitoring individual therapy.

Dose-response efficacy of a new estradiol transdermal matrix patch for 7-day application: a randomized, double-blind, placebo-controlled study. Italian Menopause Research Group

New estradiol (E2) transdermal matrix patches developed for once-a-week application, releasing 25 micrograms E2 (7D-25) or 50 micrograms E2 (7D-50) daily, were investigated in comparison with a placebo patch and the twice-weekly parent patch releasing 50 micrograms E2 (Derm-50) daily. Three hundred and eleven postmenopausal patients suffering at least seven hot flushes daily were randomly assigned to the four parallel groups and treated continuously for 12 weeks without progestin opposition. The daily number of hot flushes significantly decreased in all groups. At the 12th week the decrease from a base-line average of eight to nine episodes per day was 78% with 7D-25, 93% and 97% respectively with 7D-50 and Derm-50, and significantly (p < 0.001) lower with placebo (59%). Comparable efficacy was observed in terms of severity of hot flushes, Kupperman Index and patient self-rated overall efficacy. Minor systemic adverse events occurred in 10.0%, 8.8%, 16.9% and 13.5% patients in the placebo, 7D-25, 7D-50 and Derm-50 groups respectively. Occasional mild and transient itching and/or erythema at the site of application was reported by a few patients, with no difference between groups or between once-weekly or twice-weekly application. In conclusion all E2 patches were significantly more effective than placebo in relieving climacteric symptoms in a dose-dependent fashion and all were well tolerated.

Comparison of gel and patch estradiol replacement in Brazil, a tropical country

OBJECTIVES

Compare the administering technique, local tolerance and clinical and laboratory response to hormone replacement therapy with 17-beta estradiol in gel and patch in Brazil, a tropical country.

METHODS

We carried out a transversal study by means of an outpatient interview completed by 66 menopausal women, 42 using gel, and 24 utilizing patches. We focused on the main problems with the two forms of replacement, in summer and at other times during the year.

RESULTS

The average daily dose of 17-beta estradiol administered was 150 microg in the GEL GROUP and 50 microg in the PATCH GROUP. Reports of itching (33.3%) and local skin reactions (54. 2%) occurred exclusively in the PATCH GROUP. The patches came detached in 54.2% of the patients. These problems were more frequent in the summer. There was no significant difference in the regularity of administering (P=0.38) nor in the levels of FSH (P=0.16) and LH (P=0.33) between the two groups. Problems with the application technique (P=0.002) and the blood levels of estradiol (P=0.0002) were greater in the GEL GROUP, while symptoms of hypoestrogenism predominated in the PATCH GROUP (P=0.002).

CONCLUSIONS

We concluded that, in our environment, the use of 17-beta estradiol in gel presented fewer local skin reactions, was more effective in alleviating the symptoms of hypoestrogenism and had better acceptance in hormone replacement therapy for menopausal women, as compared with the 17-beta estradiol patch.

Drug concentration effect relationship of estradiol from two matrix transdermal delivery systems: Menorest and Climara

OBJECTIVES

To relate the pharmacokinetics of estradiol to pharmacological effects.

METHODS

Drug concentration effect relationship of estradiol from two matrix transdermal delivery systems, Menorest and Climara, was studied in a single centre, open, randomised, comparative crossover study. The trial consisted of two treatment periods, 14 days for each patch separated by a 4-week washout period. Blood hormone levels were followed during the second week of each treatment. Estradiol levels during treatments were related to three concentration levels previously proposed as efficacy or safety limits. The effect of treatment on FSH-levels was examined and the relationship between the levels of estradiol and FSH was described using an inhibitory sigmoidal I(max) model. Estrone levels and estradiol/estrone before and during treatment were followed.

RESULTS

The C(average) of FSH during treatment was 38% lower than baseline plasma levels. Estradiol had an inhibitory effect on FSH with an I(max) of 0.68 and an IC(50) of 19 pg/ml. The fraction of time above the minimum concentration for therapeutic effect and the tolerability limit did not differ between the two treatments, whereas the fraction of time above the suggested threshold for osteoporosis prophylaxis was significantly larger for Menorest than for Climara (P<0.05). The low baseline estradiol/estrone ratios increased towards pre-menopausal levels during treatment.

CONCLUSIONS

The drug concentration effect relationship of estradiol may be of use in evaluation of the effects of prophylactic estrogen therapy and to facilitate comparisons between different forms of estrogen treatments.

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.

Effects on bone of oral hormone replacement therapy initiated 2 years after ovariectomy in young adult monkeys

The purpose of this study was to determine the effects of oral estrogen replacement therapy with conjugated equine estrogens (CEE), alone or in combination with continuous medroxyprogesterone acetate (MPA), on lumbar spine bone mineral content (BMC) and density (BMD) and on serum chemistries in ovariectomized cynomolgus monkeys when therapy is initiated following a 2 year hypoestrogenic period. Study design was done in the form of a randomized, placebo-controlled, nonhuman primate paraclinical trial. Monkeys were subjects in an experiment designed to study the effects of a lipid-lowering diet combined with hormone replacement therapy on atherosclerosis. Initially, they were ovariectomized and fed a high-fat diet for 24 months. They were then were allocated to three treatment groups by stratified randomization and were fed a diet containing reduced dietary fat for an additional 28 months. Treatment groups consisted of: (1) an untreated group (ovx, n = 24); (2) a CEE-treated group (CEE, n = 19); and (3) a CEE plus continuous MPA group (CEE + MPA, n = 20). Lumbar spine BMC and BMD values were measured by dual-energy x-ray absorptiometry at baseline and 4, 10, 16, 22, and 28 months of treatment. Serum chemistries were relevant to bone metabolism at 22 and 28 months. Rates of gain in BMC and BMD were greater (p < 0.05) in hormone-supplemented animals (groups 2 and 3) than in untreated ovx animals during the first 16 months of treatment, resulting in increased BMC and BMD measurements in these groups. Serum markers of bone metabolism were significantly lower (p < 0.05) in the hormone-treated groups (groups 2 and 3) compared with ovx animals after 22 and 28 months of treatment, indicating reductions in bone turnover rate. Oral estrogen replacement with CEE at doses similar to those taken by women leads to significantly increased BMC and BMD in monkeys, even when therapy is begun 2 years after ovariectomy. Most of the increase occurred during the first 16 months of treatment. The addition of MPA to the CEE regimen provided no additional benefit.

Estrogen therapy and osteoporosis: principles & practice

Postmenopausal osteoporosis is linked clearly to estrogen deprivation. Recent research has identified estrogen receptors in bone cells and in other organ systems that help to regulate bone remodeling and calcium homeostasis. Long-term use of estrogen in appropriate doses reduces the risk of hip fractures by 50% to 60% and the risk of vertebral deformation by 90%. This protective effect is maintained as long as estrogen is taken and adequate levels of biologically active estrogen are achieved. Thus, the type, dose, and route of administration of estrogen need to be individualized and the efficacy of treatment monitored by annual bone density testing and selective ultilization of biochemical bone markers. The ability of estrogen therapy to increase bone mass is enhanced by added androgens and progestin therapy, calcium supplementation, and exercise.

Effect of 17beta-estradiol-bisphosphonate conjugates, potential bone-seeking estrogen pro-drugs, on 17beta-estradiol serum kinetics and bone mass in rats

In order to target 17beta-estradiol directly at bone we synthesized three 17beta-estradiol-bisphosphonate conjugates (E2-BPs) with different esterase-sensitive linkers between both molecular moieties. The systemic administration of these compounds should result primarily in local estrogenic effects on bone with no or negligible systemic hormonal effects. Only if a considerable margin exists between the doses required for inhibition of bone loss and those for systemic hormonal effects can such a pro-drug be considered acceptable for patients refusing systemic estrogen replacement therapy for several reasons. The conjugates were tested in vitro for their 17beta-estradiol release in rat serum and in vivo for their local and systemic effects in rats: in vitro, the conjugates expressed cleavage resistance, low cleavage (4.8%), or high cleavage (33.1%) within 48 hours of incubation. The conjugate with the low-cleavage doubled 17beta-estradiol serum half-life (3.78 hours) whereas the high-cleavage conjugate resulted in approximately four times higher serum half-life (8.36 hours) when compared with free 17beta-estradiol. In ovariectomized rats, bone loss was optimally prevented by 50 nmol/kg/day of 17beta-estradiol when administered S. C. over a period of 5 weeks, and protection against uterine atrophy was achieved at doses as low as 5 nmol/kg/day. The cleavage-resistant conjugate was ineffective in preserving bone and uterus in doses ranging from 5 to 150 nmol/kg/day. The other two E2-BPs revealed a dose-dependent inhibition of bone loss which was paralleled by the respective uterus weight with a dose range of 1.5-150 nmol/kg/day being fully effective in a range similar to 17beta-estradiol alone. The higher sensitivity of the uterus versus bone to protective estrogenic effects (1:10) was abolished by the conjugates. We conclude that E2-BPs containing esterase-sensitive linkers failed to act as bone-seeking pro-drugs expressing primarily local effects on bone without systemic effects.

17 beta-estradiol increases calcium content in fetal mouse parietal bones cultured in serum-free medium only at physiological concentrations

Using a bone organ culture system that shows mineralization in vitro, we investigated whether 17 beta-estradiol dose-dependently increases calcium content in cultured calvarial bones in serum-free medium. Fetal mouse parietal bones (3 x 3 mm) were cultured in phenol red-free BGJ medium containing phosphate (3-4 mmol/L), calcium (1-1.25 mmol/L), insulin (6 micrograms/ML), and transferrin (6 micrograms/mL) for 4-5 days. Under these culture conditions, the calcium content of the cultured bones (at dissection 34.0 +/- 4.6 micrograms/bone [mean +/- SD], n = 50) increased by 15-20 micrograms during 4-5 days of culture. 17 beta-Estradiol increased the calcium content significantly at 10(-12) to 10(-11) mol/L, but not at lower (10(113) mol/L) or higher (10(-10) to 10(-9) mol/L) concentrations. 17 alpha-Estradiol had no effect. The stimulatory effect of 17 beta-estradiol was completely inhibited by the antiestrogen agent ICI-182,780. The anabolic effect of 17 beta-estradiol was elicited not only in bones from females but also in those from males. 17 beta-Estradiol had no significant effect on 45Ca release from prelabeled parietal bones. Furthermore, light- and electron-microscopic examinations revealed that bone mineralization proceeded through formation of matrix vesicles, without any metastatic or dystrophic calcification. These in vitro findings suggest that 17 beta-estradiol elicits small, but reproducible, direct effects on calcium content in the parietal bones not only in female but also in male fetal mice at physiological-free E2 concentrations (10(-12)-10(-11) mol/L), which is attainable in serum of normal human subjects. In contrast to in vivo studies, pharmacological doses of 17 beta-estradiol had no anabolic effect on parietal bones. The mechanism of such a biphasic effect of estrogens remains to be elucidated.

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

Osteoporosis prevention and treatment with sex hormone replacement therapy

Oestrogen deficiency is by far the major factor contributing to the high rate of osteoporotic fractures in women. The anti-osteoporotic effect of estrogen may be explained by its property to regulate cytokine secretion and thus balance bone remodeling. In oestrogen deficiency, increased resorption and remodeling will occur leading to osteoporosis. It has been extensively shown that oestrogen replacement therapy (ERT) prevents postmenopausal bone loss and reduces fracture risk by half, provided that an appropriate dose is used. In order to optimize osteoporosis prevention, ERT should be started a early as possible in menopause and be maintained as long as possible. ERT may also be effective in elderly osteoporotic patients in preventing bone loss and, reducing fracture risk. The acceptance of ERT, however, at an older age has not been thoroughly evaluated. A reduction of cardiovascular disease and of climateric symptoms are among other benefits of ERT. So far, only few postmenopausal women are treated with ERT. ERT without progestins has been repeatedly found associated with an increased risk of developing endometrial cancer, but the cyclic addition of progestins protects from endometrial hyperplasia and carcinoma. Combined oestrogen-progestin therapy is as efficient as estrogen therapy alone, but not more so. Since progestins may oppose some of the beneficial effects of estrogens, the lowest dose with the least metabolic impact should be prescribed. Women who have had a hysterectomy, should probably be treated by estrogen replacement therapy only. Meta-analyses concerning breast cancer associated with ERT found a very moderately increased risk (RR = 1.06). Therefore ERT prescription should be discussed openly with women considering all risks and benefits. In women who have suffered from breast cancer, a bone sparing effect of tamoxifen has been shown.

Pharmacokinetic and pharmacologic variation between different estrogen products

Due to the complex nature of endogenous and exogenous hormone concentration, formation, and metabolism and assay complexity, the pharmacokinetics of estrogen are difficult to study. Oral estrogens have minimal systemic bioavailability (2% to 10%) due to gut and liver (first-pass) metabolism. High concentrations of estrone are achieved with oral administration, whereas higher concentrations of estradiol are generally achieved after percutaneous absorption. Although vaginal products (such as gel, rings, etc.) are administered locally, they achieve high serum concentrations. Estradiol and estrone concentrations and estradiol-to-estrone ratios vary with different estrogen therapies. Approximately 95% to 98% of estradiol is bound loosely to albumin or tightly to sex hormone binding globulin, the major binding protein. The terminal half lives for the different estrogen compounds (after oral or intravenous administration) vary from 1-12 hours. Some conversion rates have been calculated between estrogen and its metabolites. Smoking decreases achievable estrogen concentrations, and has a greater effect on oral products. Oral contraceptives have been found to decrease antipyrine clearance. In the one study evaluating conjugated estrogens, antipyrine clearance was not altered. Oral contraceptives have a variable effect on the elimination of medications. Acetaminophen clearance is increased, whereas clearance of some benzodiazepines, caffeine,and prednisolone is decreased. Phenytoin increases the metabolism of conjugated estrogens. The various estrogen products may produce different clinical effects based on composition. The metabolites (minor components) of conjugated estrogens have been found to have significant effects on lipid concentrations, uterine weight, liver generated compounds, and bone resorption. Because transdermal products bypass the first-pass effect, delayed or decreased effects on lipid profiles and liver generated compounds have been observed.

Bone metabolism and osteopenia in eating disorders

Bone loss is a potentially debilitating condition in women with eating disorders. Complications may include failure to achieve peak bone mass, increased risk of premature fractures, and inability to reach the height potential. We therefore conducted a comprehensive evaluation of 58 women with anorexia nervosa (AN), bulimia (BUL) and anorexia/bulimia (AB), comparing bone mineral density (BMD) to physical parameters, biochemical indices, and markers for bone formation and resorption. BMDs were significantly lower in patients with AN than in those with AB and BUL, and overt osteopenia was uncommon in AB and BUL. Hypercortisolism was the best laboratory marker to assess the risk of osteopenia in patients with AN. However, there were no associated changes in bone formation or resorption parameters. No direct correlation was found between BMD and body mass index, estrogen deficiency, tubular reabsorption of phosphorus, serum vitamin D, PTH, BGP, or alkaline phosphatase levels. Although the prognosis for complete recovery to normal BMD is poor, treatment of the underlying depressive disorder, improvement in nutrition with increased weight, and spontaneous resumption of menses are associated with restoring bone health.

Prevention of postmenopausal bone loss by rectal calcitonin

A group (150) of healthy women, who had been menopausal for less than 5 years and who had never received any form of treatment to prevent bone loss were entered into a randomized, controlled study comprising three arms. They were randomly allocated to the double-blind administration of five suppositories per week containing either 100 IU of salmon calcitonin or a placebo, or to a group receiving a suppository containing 200 IU of salmon calcitonin three times per week. All women received 500 mg/day of calcium supplementation. After 12 months, bone mineral density (BMD) of the spine, measured by dual energy X-ray absorptiometry, decreased significantly (P < 0.01) in the placebo group by 3.1% (SD: 3.6%) but did not change in the two calcitonin groups [+1.3% (3.5%) with 100 IU/day and +2.3% (4.0%) with 200 IU 3/week]. The differences in response between the placebo group and the two calcitonin groups were significant (P < 0.05), but the difference between the two regimens of calcitonin administration was not. No differences appeared among the three groups for the response at the level of the hip. Evolution of biochemical markers reflecting bone turnover did not differ significantly among groups. Nearly 40% of the women withdrew prematurely because of local (rectal or intestinal) intolerance to repetitive suppositories, with a nonsignificantly different frequency in the placebo or calcitonin groups. We conclude that rectal calcitonin might be an interesting preventive approach against trabecular postmenopausal bone loss but that long-term acceptability of suppositories should be evaluated in view of each patient's sensibility or cultural background.

Cyclical clodronate is effective in preventing postmenopausal bone loss: a comparative study with transcutaneous hormone replacement therapy

An investigative study was carried out for 2 years involving 124 randomly selected early postmenopausal women with spine bone mineral density (BMD) below the mean value of a normal premenopausal subject. After random division into three groups, the first 42 patients were treated with transcutaneous 17-beta-estradiol (50 micrograms daily), the second 42 were treated with cyclical intravenous clodronate (200 mg/month iv infusion), and the third group of 40 (controls) was left untreated. After 2 years, the total drop in BMD within the control group was more than 7% as opposed to the values of -0.14% +/- 0.93 in the estradiol group and 0.67% +/- 0.84 in the clodronate group. A change in BMD of < 1% was considered satisfactory, and this result was obtained in 32% of the controls, in 79% of the estradiol group where the percentage change in BMD moderately correlated with serum estradiol levels (r = 0.399), and in 90% of the clodronate-treated patients, in whom the percentage change in BMD inversely correlated with basal values of markers of bone turnover. Both estrogen and clodronate prevent postmenopausal bone loss. The response to transcutaneous hormone replacement therapy may be influenced by transcutaneous absorption and by a lower sensitivity to estrogen. Response to cyclical clodronate seems to be influenced by the rate of bone turnover. An interdosage interval ranging from 2-4 weeks appears suitable for most patients.

Bone functional changes in intact, ovariectomized, and ovariectomized, hormone-supplemented adult cynomolgus monkeys (Macaca fascicularis) evaluated by serum markers and dynamic histomorphometry

Several parameters of bone mass and function were investigated in three experiments involving intact, ovariectomized, or hormone-supplemented ovariectomized female cynomolgus monkeys. Ovariectomized animals had increased serum levels of alkaline phosphatase and acid phosphatase compared with intact and hormone-supplemented animals. Vertebral bone mass measured ex vivo by dual-photon absorptiometry was reduced by 11-19% in ovariectomized animals compared with intact and hormone-supplemented animals. The most dramatic effects observed with ovariectomy were markedly increased (30-60%) bone formation rates in vertebral cancellous bone, primarily caused by higher activation frequency of basic multicellular units of bone. In addition, combined resorption and reversal periods were decreased and formation period increased in untreated ovariectomized animals. Changes in static histomorphometry parameters were less dramatic, cancellous bone volume being 1-14% lower in ovariectomized animals compared with intact or ovariectomized hormone-supplemented animals. The data indicate that changes in bone resorption are primarily responsible for the lower bone mass of estrogen deficiency and increased bone mass in hormone-supplemented animals. Bone changes in ovariectomized cynomolgus monkeys resemble those in women after menopause and similarly respond positively to hormone supplementation. As such, cynomolgus monkeys are an excellent model for studying the basic mechanisms of osteoporosis and for the development of suitable therapeutic regimens.

Prevention of osteoporosis with nasal salmon calcitonin: effect of anti-salmon calcitonin antibody formation

The amino acid sequence of salmon calcitonin (SCT) differs considerably from that of the human hormone and specific antibodies (Ab) develop in a significant proportion of patients after parenteral or nasal administration of SCT. Controversy remains regarding the functional importance of these Ab. We report on the development of specific anti-SCT Ab in a population of postmenopausal women receiving nasal SCT for prevention of postmenopausal bone loss, and compare the effects of nasal SCT in women with or without Ab. Thirty-nine per cent of women developed Ab after 6 months of treatment with SCT, 52% after 12 months, and 61% after 18 and 24 months. After 24 months the AB titre was 3.47-17.7 x 10(-9) M/l (mean +/- SD: 13.3 +/- 3.1 x 10(-9) M/l). No significant differences appeared between the changes in lumbar bone mineral density (BMD) measured in the whole population (n = 44) (mean +/- SD: +1.06 +/- 3.9%), the patients without Ab (n = 17) (+0.05 +/- 3.7%) or in those with Ab (n = 27) (+1.7 +/- 4.6%). During the same period, a control population randomly assigned to a 500 mg/day calcium intake showed a significant loss of lumbar BMD (-4.57 +/- 4.9%) (p < 0.01). In conclusion, in healthy postmenopausal women nasal SCT seems to maintain the same preventive effect against bone loss whether or not Ab are present.

Effect of transdermal 17 beta-estradiol and oral conjugated equine estrogens on biochemical parameters of bone resorption in natural menopause

OBJECTIVE

To evaluate and compare the effects or oral and transdermal estrogen replacement therapy on biochemical markers of bone resorption in early postmenopausal women.

DESIGN

Controlled, randomized group comparison.

SETTING

Outpatient clinic for menopausal women and research into osteoporosis.

SUBJECTS

Sixty healthy women menopausal for less than 5 years and who had never received any medications interfering with bone metabolism.

INTERVENTIONS

The 60 women were randomly allocated to 3 months therapy with either oral conjugated estrogens (0.625 mg/day) (n = 28) or transdermal estradiol (50 micrograms/day) (n = 32) in cyclical combination with medroxyprogesterone acetate (5 mg/day).

MAIN OUTCOME MEASURES

Traditional (urinary calcium/creatinine and hydroxyproline/creatinine) and the new specific (urinary pyridinoline/creatinine and deoxypyridinoline/creatinine) markers of bone resorption were determined before and after 3 months of treatment.

RESULTS

In both groups, circulating levels of estrone and estradiol were significantly (P < 0.001) increased during treatment. In women treated with oral conjugated equine estrogens, urinary calcium/creatinine and hydroxyproline/creatinine ratios were significantly (P < 0.05) reduced. Pyridinoline/creatinine ratio fell from 69.1 (4) [mean (SEM)] to 50 (4) mumol/mumol (P < 0.01) and deoxypyridinoline/creatinine ratio fell from 10.8 (1) [mean (SEM)] to 8.3 (0.8) mumol/mumol (P < 0.01). In the group treated with transdermal estradiol, urinary hydroxyproline/creatinine ratio was significantly (P < 0.05) reduced. Pyridinoline/creatinine ratio fell from 66.3 (4) [mean (SEM)] to 46.2 (3) mumol/mumol (P < 0.01) and deoxypyridinoline/creatinine ratio fell from 11.5 (1.5) [mean (SEM)] to 7.7 (0.6) mumol/mumol (P < 0.01). There were no differences between the evolution of the biochemical variables in the two groups.

CONCLUSION

These results suggest that oral conjugated equine estrogens and transdermal estradiol, in the given doses, are equally effective in reducing postmenopausal bone resorption.

[Preventive drug therapy of postmenopausal osteoporosis]

Osteoporosis, one of the most important disorders associated with aging, needs active prevention. Estrogen therapy prevents the early phase of bone loss and decreases the incidence of subsequent osteoporosis related fractures. All estrogens are probably not equally effective against post menopausal bone loss. In USA conjugated equine estrogens are the most used. In Europe estrogen therapy is usually applied with 17 beta estradiol with different ways of administration. If estrogen therapy cannot be used, there are limited datas about the use of bisphosphonates or calcitonins in the prevention of post menopausal bone loss, but not still any data about the subsequent incidence of fractures. In all cases, calcium supplementation is effective.