17beta-estradiol (1 mg/day) continuously combined with dydrogesterone (5, 10 or 20 mg/day) increases bone mineral density in postmenopausal women

Ataluren prevented bone loss induced by ovariectomy and aging in mice through the BMP-SMAD signaling pathway

Both estrogen deficiency and aging may lead to osteoporosis. Developing novel drugs for treating osteoporosis is a popular research direction. We screened several potential therapeutic agents through a new deep learning-based efficacy prediction system (DLEPS) using transcriptional profiles for osteoporosis. DLEPS screening led to a potential novel drug examinee, ataluren, for treating osteoporosis. Ataluren significantly reversed bone loss in ovariectomized mice. Next, ataluren significantly increased human bone marrow-derived mesenchymal stem cell (hBMMSC) osteogenic differentiation without cytotoxicity, indicated by the high expression index of osteogenic differentiation genes (OCN , BGLAP, ALP, COL1A, BMP2, RUNX2). Mechanistically, ataluren exerted its function through the BMP-SMAD pathway. Furthermore, it activated SMAD phosphorylation but osteogenic differentiation was attenuated by BMP2-SMAD inhibitors or small interfering RNA of BMP2. Finally, ataluren significantly reversed bone loss in aged mice. In summary, our findings suggest that the DLEPS-screened ataluren may be a therapeutic agent against osteoporosis by aiding hBMMSC osteogenic differentiation.

Uterine bleeding with hormone therapies in menopausal women: a systematic review

Uterine bleeding is a common reason why women discontinue menopausal hormone therapy (HT). This systematic review compared bleeding profiles reported in studies for continuous-combined HT approved in North America and Europe for moderate to severe vasomotor symptoms in postmenopausal women with a uterus. Non-head-to-head studies showed that uterine bleeding varies by formulation and administration route, with oral having a better bleeding profile than transdermal formulations. Cumulative amenorrhea over a year ranged from 18 to 61% with oral HT and from 9 to 27% with transdermal HT, as reported for continuous-combined HT containing 17β-estradiol (E2)/progesterone (P4) (56%), E2/norethisterone acetate (NETA) (49%), E2/drospirenone (45%), conjugated equine estrogens/medroxyprogesterone acetate (18-54%), ethinyl estradiol/NETA (31-61%), E2/levonorgestrel patch (16%), and E2/NETA patch (9-27%). Amenorrhea rates and the mean number of bleeding/spotting days improved over time. The oral E2/P4 combination was amongst those with lower bleeding rates and may be an appropriate alternative for millions of women seeking bioidentical HT and/or those who have bleeding concerns with other HT.

Bone protection for early menopausal women in China: standard or half-dose estrogen with progestin? A one-year prospective randomized trail

The aim of the study is to compare the bone sparing effect of half-dose with standard-dose conjugated equine estrogen (CEE) combined with progestin. A total of 123 participants were administrated with 0.625 mg of CEE and 100 mg of micronized progesterone (MP) in group A, 0.3 mg of CEE and 100 mg of MP in group B, 0.625 mg of CEE and 10 mg of dydrogesterone (DDG) in group C for one year. Percent changes from baseline in BMD at lumbar spine and fracture rate were primary outcomes. Secondary endpoints included changes of BMD at femoral neck, total hip and arm, bone markers (alkaline phosphatase, calcium and phosphorus), serum alanine aminotransferase (ALT) and endometrial thickness. No fractures occurred during the treatment. Standard dose of CEE leads to significant changes in lumbar spine and arm. The 3.78% growth of BMD at femoral neck in group C marked a statistically difference. There was no statistically remarkable bone loss at hip in all three groups. Bone turnover markers and ALT significantly decreased from basic values. Endometrium thickened more with traditional dose of CEE. Both the half and standard dose CEE are effective in BMD preservation among early menopausal women with subtle side effects. Low-dose estrogen is less efficacious than traditional one.

Oral estradiol and dydrogesterone combination therapy in postmenopausal women: review of efficacy and safety

HRT is known to be effective for the relief of menopausal symptoms and prevention of osteoporosis. HRT should be tailored to the woman, enhancing the beneficial effects of the treatment while minimizing the risks. It is difficult to evaluate data on particular preparations of HRT and the different dosages in isolation. The purpose of this review is to highlight the efficacy and safety specific to oral estradiol and dydrogesterone combinations of four different dose strengths. A systematic literature search using Medline was carried out to identify studies containing efficacy or safety data. The findings of the retrieved publications confirm that estradiol and dydrogesterone combinations give very effective menopausal symptom relief and prevention of osteoporosis whilst maintaining a good safety profile. Data also show that these combinations of HRT give additional benefit to certain metabolic parameters including lipids, insulin, glucose and body fat distribution. By selecting the treatment and dose most suitable for each individual woman at her particular stage of menopause, the benefits can be optimized whilst mitigating the risks. HRT plays an important role in improving and maintaining women's health when used appropriately.

Hormone therapy in postmenopausal women and risk of endometrial hyperplasia

BACKGROUND

Reduced circulating estrogen levels around the time of the menopause can induce unacceptable symptoms that affect the health and well-being of women. Hormone therapy (both unopposed estrogen and estrogen/progestogen combinations) is an effective treatment for these symptoms, but is associated with risk of harms. Guidelines recommend that hormone therapy be given at the lowest effective dose and treatment should be reviewed regularly. The aim of this review is to identify the minimum dose(s) of progestogen required to be added to estrogen so that the rate of endometrial hyperplasia is not increased compared to placebo.

OBJECTIVES

The objective of this review is to assess which hormone therapy regimens provide effective protection against the development of endometrial hyperplasia or carcinoma.

SEARCH METHODS

We searched the Cochrane Menstrual Disorders and Subfertility Group trials register (searched January 2012), The Cochrane Library (Issue 1, 2012), MEDLINE (1966 to January 2012), EMBASE (1980 to January 2012), Current Contents (1993 to May 2008), Biological Abstracts (1969 to 2008), Social Sciences Index (1980 to May 2008), PsycINFO (1972 to January 2012) and CINAHL (1982 to May 2008). Attempts were made to identify trials from citation lists of reviews and studies retrieved, and drug companies were contacted for unpublished data.

SELECTION CRITERIA

Randomised comparisons of unopposed estrogen therapy, combined continuous estrogen-progestogen therapy, sequential estrogen-progestogen therapy with each other or placebo, administered over a minimum period of 12 months. Incidence of endometrial hyperplasia/carcinoma assessed by a biopsy at the end of treatment was a required outcome. Data on adherence to therapy, rates of additional interventions, and withdrawals owing to adverse events were also extracted.

DATA COLLECTION AND ANALYSIS

In this update, 46 studies were included. Odds ratios (ORs) were calculated for dichotomous outcomes. The small numbers of studies in each comparison and the clinical heterogeneity precluded meta-analysis for many outcomes.

MAIN RESULTS

Unopposed estrogen is associated with increased risk of endometrial hyperplasia at all doses, and durations of therapy between one and three years. For women with a uterus the risk of endometrial hyperplasia with hormone therapy comprising low-dose estrogen continuously combined with a minimum of 1 mg norethisterone acetate (NETA) or 1.5 mg medroxyprogesterone acetate (MPA) is not significantly different from placebo at two years (1 mg NETA: OR 0.04; 95% confidence interval (CI) 0 to 2.8; 1.5 mg MPA: no hyperplasia events).

AUTHORS' CONCLUSIONS

Hormone therapy for postmenopausal women with an intact uterus should comprise both estrogen and progestogen to reduce the risk of endometrial hyperplasia.

Ultra low dose continuous combined hormone replacement therapy with 0.5mg 17beta-oestradiol and 2.5mg dydrogesterone: protection of the endometrium and amenorrhoea rate

OBJECTIVES AND STUDY DESIGN

The aim of this open, multicentre study was to demonstrate the endometrial safety and assess the bleeding pattern of ultra low dose continuous combined hormone replacement therapy with 0.5 mg 17beta-oestradiol and 2.5 mg dydrogesterone in 446 healthy, non-hysterectomised, postmenopausal women with symptoms of oestrogen deficiency.

MAIN OUTCOME MEASURE

Aspiration endometrial biopsies were performed at baseline and after 1 year of treatment to assess the incidence of endometrial hyperplasia or a more serious endometrial outcome.

RESULTS

The only adverse endometrial outcome at the end of the study was one case of simple hyperplasia. This gives an overall incidence of 0.27% (95% CI: 0.01-1.48%) in the per protocol sample (n=395). The overall rate of amenorrhoea in the full sample (n=446) was 68% and 14% had only one or two bleeding/spotting episodes. The rate of amenorrhoea in months 10-12 (n=413) was 88%. The number of bleeding/spotting days per cycle fell during the study. The mean number of bleeding/spotting days was 5.8 and the mean number of days without bleeding was 358.2. Spotting alone was the most prevalent bleeding intensity, whilst heavy bleeding was rare.

CONCLUSIONS

In conclusion, 2.5 mg dydrogesterone continuously combined with 0.5 mg 17beta-oestradiol effectively protects the endometrium in postmenopausal women in accordance with the guidelines of the Committee for Medicinal Products for Human Use (CHMP). It has a favourable amenorrhoea rate and is well tolerated by the majority of women.

Hormone therapy in postmenopausal women and risk of endometrial hyperplasia

BACKGROUND

Declining circulating estrogen levels around the time of the menopause can induce unacceptable symptoms that affect the health and well being of women. Hormone therapy (both unopposed estrogen and estrogen/progestogen combinations) is an effective treatment for these symptoms, but is associated with risk of harms. Guidelines recommend that hormone therapy be given at the lowest effective dose and treatment should be reviewed regularly. The aim of this review is to identify the minimum dose(s) of progestogen required to be added to estrogen so that the rate of endometrial hyperplasia is not increased compared to placebo.

OBJECTIVES

The objective of this review is to assess which hormone therapy regimens provide effective protection against the development of endometrial hyperplasia and/or carcinoma.

SEARCH STRATEGY

We searched the Cochrane Menstrual Disorders and Subfertility Group trials register (searched January 2008), The Cochrane Library (Issue 1, 2008), MEDLINE (1966 to May 2008), EMBASE (1980 to May 2008), Current Contents (1993 to May 2008), Biological Abstracts (1969 to 2008), Social Sciences Index (1980 to May 2008), PsycINFO (1972 to May 2008) and CINAHL (1982 to May 2008). Attempts were made to identify trials from citation lists of reviews and studies retrieved, and drug companies were contacted for unpublished data.

SELECTION CRITERIA

Randomised comparisons of unopposed estrogen therapy, combined continuous estrogen-progestogen therapy and/or sequential estrogen-progestogen therapy with each other or placebo, administered over a minimum period of twelve months. Incidence of endometrial hyperplasia/carcinoma assessed by a biopsy at the end of treatment was a required outcome. Data on adherence to therapy, rates of additional interventions, and withdrawals due to adverse events were also extracted.

DATA COLLECTION AND ANALYSIS

In this substantive update, forty five studies were included. Odds ratios were calculated for dichotomous outcomes. The small numbers of studies in each comparison and the clinical heterogeneity precluded meta analysis for many outcomes.

MAIN RESULTS

Unopposed estrogen is associated with increased risk of endometrial hyperplasia at all doses, and durations of therapy between one and three years. For women with a uterus the risk of endometrial hyperplasia with hormone therapy comprising low dose estrogen continuously combined with a minimum of 1 mg norethisterone acetate or 1.5 mg medroxyprogesterone acetate is not significantly different from placebo (1mg NETA: OR=0.04 (0 to 2.8); 1.5mg MPA: no hyperplasia events).

AUTHORS' CONCLUSIONS

Hormone therapy for postmenopausal women with an intact uterus should comprise both estrogen and progestogen to reduce the risk of endometrial hyperplasia.

Issues concerning the use of hormone replacement therapy and risk of fracture: a population-based, nested case-control study

AIMS

To investigate the effect of duration, how recently it has been used, and age at start of hormone replacement therapy (HRT) and the risk of bone fracture.

METHODS

A population-based, nested case-control study was conducted in Lombardia, Northern Italy. The 78,294 women aged 45-75 years who received at least one HRT prescription during 1998-2000 were followed until 2005. Cases were women who experienced bone fracture during follow-up. Up to six controls were randomly selected for each case from the cohort after matching for age and date of cohort entry. The odds ratio of fracture associated with the use of HRT was estimated by conditional logistic regression.

RESULTS

One thousand one hundred and seventy-four cases and 6760 controls were included. Compared with women who took HRT for less than 2 months, those who were treated for more than 20 months had an odds ratio (OR) of 0.80 (95% confidence interval 0.65, 0.99). This risk reduction was still significant among current HRT users (OR 0.71, 95% CI 0.55, 0.90) and in women who began therapy at the age of 55-65 years (OR 0.63, 95% CI 0.42, 0.94) or 65-75 years (OR 0.56, 95% CI 0.32, 0.99). There was no statistical evidence of a protective effect for women who had stopped treatment more than 6 months previously or those who began HRT at the age of 45-55 years.

CONCLUSIONS

HRT should be continued for long periods to achieve an optimal protection from fracture. The fracture reducing potential of HRT seems to disappear after a few months without treatment and might mainly act in women who begin therapy at older age.

Serum leptin levels and body composition in postmenopausal women treated with tibolone and raloxifene

OBJECTIVE

To compare body composition and serum leptin levels in untreated postmenopausal women and postmenopausal women treated with tibolone or raloxifene.

DESIGN

This was a prospective, randomized, controlled study. Sixty-eight postmenopausal women were randomized to receive either no treatment (group A, n = 21) or tibolone 2.5 mg/day (group B; n = 23) or raloxifene 60 mg/day (group C; n = 24). All women underwent height, weight, body mass index evaluation and dual energy x-ray absorptiometry determination of body composition at the beginning of the study and after 12 months. Serum leptin levels were determined at the beginning of the study and after 1, 3, 6, and 12 months in all groups.

RESULTS

Women in group A showed no significant changes in both fat and lean mass of arms and legs, whereas a significant increase in trunk fat mass, total fat mass, total percentage of body fat, and trunk percentage of fat was detected 1 year after the beginning of the study. After 12 months, the total percentage of fat mass was significantly higher in group A compared with group B, and the trunk percentage of fat mass was significantly higher in group A compared with groups. In subjects in groups B and C, after 1 year, fat mass, both total and at all areas evaluated, did not show any significant change compared with baseline values. In subjects in group B, total lean and lean mass of the trunk and legs increased significantly at the end of the study, whereas no significant changes were observed in lean mass, total and at all areas evaluated in subjects in group C. After 12 months, total lean mass and lean mass of the legs were significantly higher in group B compared with the other groups. In group A, serum leptin levels were significantly increased at the end of the study compared with baseline values. Leptin concentrations were significantly higher in group A compared with groups B and C after 6 and 12 months. No significant change in serum leptin levels in subjects in groups B and C was detected throughout the study. Serum leptin levels showed a positive, significant correlation with all body composition parameters and body mass index in all groups at the beginning and at the end of the study.

CONCLUSIONS

The present study confirms that postmenopausal hypoestrogenism leads to increased fat content and serum leptin levels. Raloxifene and tibolone seem to prevent postmenopausal body composition changes without significant modifications of serum leptin levels.

Continuous combined hormone replacement therapy with 1mg 17β-oestradiol and 5mg dydrogesterone (Femoston®-conti): Endometrial safety and bleeding profile

OBJECTIVES

The aim of the study was to confirm the endometrial safety and describe the bleeding profile of continuous combined 1 mg 17beta-oestradiol and 5 mg dydrogesterone in post-menopausal women.

METHODS

An open, multicentre study was carried out in 290 healthy, non-hysterectomised post-menopausal women receiving oral continuous combined 1 mg 17beta-oestradiol and 5 mg dydrogesterone (Femoston-conti) for 1 year. Aspiration endometrial biopsies were performed at baseline and at the end of the study; those classified as hyperplasia or malignancy were considered treatment failures.

RESULTS

Only one woman developed simple hyperplasia without atypia at the end of the study; the treatment failure rate was therefore 0.4%. Cross-sectional analysis showed that the percentage of women without bleeding increased from 71% during the first cycle to around 80% by the end of the study. Approximately 50% of the bleeding episodes occurred in the form of spotting; severe bleeding was rare and only seven women withdrew prematurely from the study due to uterine bleeding. Overall, 41% of the women were amenorrhoeic throughout the study.

CONCLUSIONS

Continuous combined 1 mg 17beta-oestradiol and 5 mg dydrogesterone provides excellent endometrial safety and is associated with an acceptable bleeding profile.

Justification for the use of HRT in the long-term prevention of osteoporosis

Osteoporosis is a common condition in postmenopausal women and is associated with significant healthcare costs, morbidity and mortality. It is clear that long-term hormone replacement therapy (HRT) has a role to play in preventing osteoporosis by increasing bone mineral density and reducing fracture rate. It is important that these benefits, as well as those on climacteric symptoms, quality of life, colorectal carcinoma and cognition, are not underestimated in the face of the postulated risks with regard to breast cancer and cardiovascular disease. In conclusion, HRT should currently be used only for women with climacteric symptoms or an increased risk of osteoporosis, and it is important that there is an individualised approach to treatment based on each woman's risk profile.

The effect of continuous oestradiol with intermittent norgestimate on bone mineral density and bone turnover in post-menopausal women

OBJECTIVE

To assess in post-menopausal women the efficacy and tolerability of a continuous oestradiol/intermittent norgestimate HRT regimen to prevent and to reverse post-menopausal loss of bone mineral density (BMD) and to determine the effects on serum bone turnover markers markers.

METHODS

A 1-year, multicentre, international, placebo-controlled, randomised, double-blind clinical trial was conducted in 146 post-menopausal women with an intact uterus in order to assess the effect on bone loss of continuous oral 17beta-oestradiol (1 mg per day) combined with norgestimate (90 microg per day), for 3 consecutive days out of every 6-day treatment period (E2/iNGM). During a second year extension, all women agreeing to continue were on the E2/iNGM regimen. BMD was assessed prior to treatment and after 1 and 2 years or at the end of treatment in women stopping participation prematurely after at least 6 months of treatment. Serum bone turnover markers were determined prior to and at 1 year of treatment Adverse events were collected at three-monthly intervals during clinic visits over the treatment period.

RESULTS

BMD in the lumbar spine, the primary endpoint, was evaluable in 117 subjects completing >6 months of treatment. BMD increased on average by 2.4% in women on the intermittent progestin regimen. It decreased by 1.4% in placebo treated women. The change from baseline and the difference between active and placebo treatment (Delta placebo) were highly significant (P < 0.0001). On E2/iNGM, also the BMD in the total hip increased (+1.49%, Delta placebo 3.73%, P < 0.0001). The serum markers for bone formation osteocalcin and type I collagen N-propeptide were significantly reduced compared to baseline by 31 and 44%, respectively and the bone resorption marker C-terminal crosslinked telopeptide of type I collagen by 59%. Minor increases (<10%) of markers in the placebo group were not significant. During a second year extension of the trial, all subjects were on active treatment. Subjects on placebo who lost (median+/-CI 95%) 0.66% (-2.3 to +0.5) of spine BMD during the first year now gained 4.41% (2.7-7.6). They also gained 1.6% (0.1-0.3.6) in the total hip. Subjects continuously on oestradiol/intermittent norgestimate (E2/iNGM) gained an additional 5.7% (2.3-13.5) in the lumbar spine and +0.1% (-0.6 to +2.2) at the total hip. Side effects reported by women on the intermittent progestin regimen significantly in excess over reports from the placebo group were uterine bleeding, abdominal and breast pain, but not headache. Back pain and weight gain was reported by significantly fewer women on active treatment compared to placebo.

CONCLUSION

The continuous oestradiol/intermittent norgestimate HRT regimen is well tolerated, reduces bone turnover and prevents post-menopausal bone loss in healthy post-menopausal women.

Serum leptin levels and body composition in postmenopausal women: effects of hormone therapy

OBJECTIVE

To confirm the effect of postmenopausal hypoestrogenism and hormone therapy (HT) on body composition and serum leptin levels.

DESIGN

Prospective, longitudinal study evaluating body composition (body mass index, and total and percent fat mass and lean mass measured at the arms, legs and trunk) with dual-energy x-ray absorptiometry and serum leptin levels by radioimmunoassay in 44 healthy postmenopausal women randomized to receive either no treatment (n = 22) or transdermal 17beta-estradiol (50 microg/day) in continuous regimen and nomegestrol (5 mg/day for 12 days/month) in a sequential regimen (n = 22).

RESULTS

One year after the beginning of the study, in untreated women, total and trunk fat mass and percent fat were significantly increased, whereas trunk lean mass was significantly decreased. On the contrary, women treated with HT did not show any significant difference in body composition parameters. In untreated women, serum leptin levels were significantly increased at the end of the study in comparison with baseline values. Serum leptin levels at the other times evaluated were not significantly different from baseline values. In women treated with HT, serum leptin levels did not show significant changes throughout the study.

CONCLUSIONS

Untreated postmenopausal women show an increase in total and percent fat mass and a centralization of fat distribution. Serum leptin levels parallel this increase, resulting in significantly higher levels 1 year after the study. Women treated with HT are protected against these changes. This may represent a protective mechanism against cardiovascular diseases.

Hormone replacement therapy in postmenopausal women: endometrial hyperplasia and irregular bleeding

BACKGROUND

The decline in circulating oestrogen around the time of the menopause often induces unacceptable symptoms that affect the health and well being of women. Hormone replacement therapy (both unopposed oestrogen and oestrogen and progestogen combinations) is an effective treatment for these symptoms. In women with an intact uterus, unopposed oestrogen may induce endometrial stimulation and increase the risk of endometrial hyperplasia and carcinoma. The addition of progestogen reduces this risk but may cause unacceptable symptoms, bleeding and spotting which can affect adherence to therapy.

OBJECTIVES

The objective of this review is to assess which hormone replacement therapy regimens provide effective protection against the development of endometrial hyperplasia and/or carcinoma with a low rate of abnormal vaginal bleeding.

SEARCH STRATEGY

We searched the Cochrane Menstrual Disorders and Subfertility Group trials register (searched January 2003), The Cochrane Library (Issue 2, 2003), MEDLINE (1966 to January 2003), EMBASE (1980 to January 2003), Current Contents (1993 to January 2003), Biological Abstracts (1969 to 2002), Social Sciences Index (1980 to January 2003), PsycINFO (1972 to February 2003) and CINAHL (1982 to January 2003). The search strategy was developed by the Cochrane Menstrual Disorder and Subfertility Group. Attempts were also made to identify trials from citation lists of review articles and drug companies were contacted for unpublished data. In most cases, the corresponding author of each included trial was contacted for additional information.

SELECTION CRITERIA

The inclusion criteria were randomised comparisons of unopposed oestrogen therapy, combined continuous oestrogen-progestogen therapy and sequential oestrogen-progestogen therapy with each other and placebo administered over a minimum treatment period of six months. Trials had to assess which regimen was the most protective against the development of endometrial hyperplasia/carcinoma and/or caused the lowest rate of irregular bleeding.

DATA COLLECTION AND ANALYSIS

Sixty RCTs were identified. Of these 23 were excluded and seven remain awaiting assessment. The reviewers assessed the thirty included studies for quality, extracted the data independently and odds ratios for dichotomous outcomes were estimated. Outcomes analysed included frequency of endometrial hyperplasia or carcinoma, frequency of irregular bleeding and unscheduled biopsies or dilation and curettage, and adherence to therapy.

MAIN RESULTS

Unopposed moderate or high dose oestrogen therapy when compared to placebo was associated with a significant increase in rates of endometrial hyperplasia with increasing rates at longer duration of treatment and follow up. Odds ratios ranged from (1 RCT; OR 5.4, 95% CI 1.4 to 20.9) for 6 months of treatment to (4 RCTs; OR 9.6, 95% CI 5.9 to 15.5) for 24 months treatment and (1 RCT; OR 15.0, 95% CI 9.3 to 27.5) for 36 months of treatment with moderate dose oestrogen (in the PEPI trial, 62% of those who took moderate dose oestrogen had some form of hyperplasia at 36 months compared to 2% of those who took placebo). Irregular bleeding and non adherence to treatment were also significantly more likely under these unopposed oestrogen regimens that increased bleeding with higher dose therapy. Although not statistically significant, there was a 3% incidence (2 RCTs) of hyperplasia in women who took low dose oestrogen compared to no incidence of hyperplasia in the placebo group. The addition of progestogens, either in continuous combined or sequential regimens, helped to reduce the risk of endometrial hyperplasia and improved adherence to therapy. At longer duration of treatment, continuous therapy was more effective than sequential therapy in reducing the risk of endometrial hyperplasia. There was evidence of a higher incidence of hyperplasia under long cycle sequential therapy (progestogen given every three months) compared to monthly sequential therapy (progestogen given every month). No increase in endometrial cancer was seen in any of t in any of the treatment groups during the duration (maximum of six years) of these trials. During the first year of therapy irregular bleeding and spotting was more likely in continuous combined therapy than sequential therapy. However, during the second year of therapy bleeding and spotting was more likely under sequential regimens.

REVIEWERS' CONCLUSIONS

There is strong and consistent evidence in this review that unopposed oestrogen therapy, at moderate and high doses, is associated with increased rates of endometrial hyperplasia, irregular bleeding and consequent non adherence to therapy. The addition of oral progestogens administered either sequentially or continuously is associated with reduced rates of hyperplasia and improved adherence to therapy. Irregular bleeding is less likely under sequential than continuous therapy during the first year of therapy but there is a suggestion that continuous therapy over long duration is more protective than sequential therapy in the prevention of endometrial hyperplasia. Hyperplasia is more likely when progestogen is given every three months in a sequential regimen compared to a monthly progestogen sequential regimen.

Overview on the effects of progestins on bone

In view of the fact that fractures are the clinically relevant events, risk factors for fractures are discussed first. Bone mineral density (BMD) appears to be a much less important risk factor for the most severe hip fractures than the risk of falling. No results of experimental studies on hormones and fractures at advanced age are available. An overview of the effects of progestins on bone is given. Effects of progestins on bone have been studied by in vitro experiments using cell lines and by more relevant clinical observations. Prospective studies have been conducted following the use of progestins contained in oral contraceptives, alone or in combination with oestrogens; long-term contraception by injection of depot preparations; so-called "add-back" hormonal therapy attempting to reverse the adverse effects of gonadotropin releasing hormone agonists on bone and after different regimens of hormone replacement therapy (HRT) in postmenopausal women. From the data there are no indications that the various progestins, used in clinical practice, have either a bone-protective or an oestrogen antagonistic activity. Progestins do not add or subtract much of the protective action of oestrogens on the bones.

Use of dydrogesterone as a progestogen for oral contraception

Dydrogesterone is a potent orally active progestogen that has been used in clinical practice for over 40 years. Chemically, it belongs to the class of retrosteroids. Dydrogesterone is closely related to endogenous progesterone. It differs from most other synthetic progestogens in that it has no estrogenic, androgenic, glucocorticoid, or anabolic effects. The use of progestogens such as dydrogesterone is indicated in all cases of relative or absolute endogenous progesterone deficiency. Nowadays, dydrogesterone is mainly used in hormone replacement therapy (HRT). The present pilot study explored whether dydrogesterone could also be used as a progestogen for oral contraception. Given its highly favorable safety and tolerability profile, it would provide improvement over existing progestogens currently used in oral contraceptives (OCs). The results of this study indicate that dydrogesterone might indeed be a suitable candidate for use in oral contraception. This concept is currently being investigated further in two open-label phase II trials.

Oral 17beta-estradiol (1 mg) continuously combined with dydrogesterone improves the serum lipid profile of postmenopausal women

OBJECTIVE

To investigate the effects of 1 mg 17beta-estradiol continuously combined with 2.5, 5, 10, or 20 mg dydrogesterone on the serum lipid profile of postmenopausal women.

DESIGN

Serum lipid profile was measured in two 1-year studies performed in healthy, nonhysterectomized, postmenopausal women. One study (n = 182) had an open design and investigated oral 17beta-estradiol 1 mg daily continuously combined with dydrogesterone 2.5 mg daily; the other study (n = 326) had a double-blind, randomized design and investigated oral 17beta-estradiol 1 mg daily continuously combined with dydrogesterone at doses of 5, 10, or 20 mg daily.

RESULTS

With all four dosages of dydrogesterone, serum total and low-density lipoprotein cholesterol were significantly reduced (-4.6% to -7.6% and -6.3% to -11.6%, respectively), whereas high-density lipoprotein cholesterol was significantly increased (+4.3% to +7.4%). Serum apolipoprotein A1 and B also improved significantly, reflecting the favorable changes in high-density lipoprotein and low-density lipoprotein cholesterol, as did lipoprotein(a).

CONCLUSION

Oral 17beta-estradiol 1 mg daily continuously combined with dydrogesterone 2.5 to 20 mg daily has beneficial effects on serum lipid profile in postmenopausal women.