Prevention of postmenopausal bone loss using tibolone or conventional peroral or transdermal hormone replacement therapy with 17beta-estradiol and dydrogesterone

Effect of Tibolone on Bone Mineral Density in Postmenopausal Women: Systematic Review and Meta-Analysis

Low bone mineral density (BMD) on postmenopausal women causes bone fragility and fracture risk. Tibolone seems to prevent bone loss. Therefore, this systematic review with meta-analysis synthesizes the tibolone effect on BMD percent change in lumbar spine (LS), femoral neck (FN), and total hip (TH) in postmenopausal women. Controlled trials that provided tibolone evidence on the efficacy of tibolone in preventing loss of BMD were included. Regarding the included studies, a pooled mean difference (MD) with 95% confidence intervals (95%CI) was estimated to determine the BMD percentage change. Eleven studies were identified and eight were included in the quantitative analysis. Tibolone at a dose of 2.5 mg increased BMD compared with non-active controls at 24 months in LS (MD 4.87%, 95%CI: 4.16-5.57, and MD 7.35%, 95%CI: 2.68-12.01); and FN (MD 4.85%, 95%CI: 1.55-8.15, and 4.21%, 95%CI: 2.99-5.42), with Hologic and Lunar scanners, respectively. No difference was observed when tibolone 2.5 mg dose was compared with estrogen therapy (ET) at 24 months, LS (MD -0.58%, 95%CI: -3.77-2.60), FN (MD -0.29%, 95%CI: -1.37-0.79), and TH (MD -0.12%, 95%CI: -2.28-2.53). Therefore, tibolone increases BMD in LS and FN compared to non-active controls, and there was no showed difference with ET.

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.

Tibolone in postmenopausal women: a review based on recent randomised controlled clinical trials

AIM

To critically discuss the use of tibolone (T), in light of a series of very recent double-blind placebo (PL) controlled trials (LISA, LIFT, OPAL, THEBES, LIBERATE) conducted worldwide in a large number of postmenopausal women (PMW).

METHODS

The most relevant publications on T therapy in PMW were considered with emphasis on menopausal symptoms, quality of life, sexuality, bone, cardiovascular system (CVS) and oncologic risk.

RESULTS

T significantly relieves climacteric symptoms and improves mood and sexual well-being (LISA). T is as effective as estrogen-progestin therapy in preventing bone loss and reducing the relative risk of vertebral and non-vertebral fractures (LIFT). By using surrogate endpoints of the individual risks for the CVS, studies show mixed results, but a favourable effect on acute miocardial infarction and thromboembolism has been documented (THEBES, LIFT, OPAL). Although findings about endometrial and colon cancer are reassuring, conclusive data on breast cancer risk with T are not available and an increased risk of recurrence in women with previous breast cancer emerged (LIBERATE).

CONCLUSIONS

T is effective in treating menopausal syndrome with a good tolerability profile. In spite of some unsolved issues in term of safety, T is still a good treatment option for early PMW.

Effects of tibolone on blood flow resistance and intima-media thickness of the carotid arteries: effect of time since menopause

OBJECTIVE

The aim of this prospective study was to evaluate the effects of tibolone on carotid atherosclerosis in healthy postmenopausal women.

METHODS

Twenty-five healthy postmenopausal women were included in the study. Patients received tibolone 2.5 mg daily for 6 months. Resistance indices of the common carotid artery (CCA), internal carotid artery (ICA), external carotid artery (ECA) and vertebral arteries, and intima-media thickness of the CCA were measured both at baseline and at the end of the study with ultrasonography.

RESULTS

No significant differences were observed in the resistance indices of the CCA, ICA, ECA and vertebral arteries, as well as intima-media thickness of CCA at 6 months in comparison with baseline. Tibolone significantly improved the intima-media thickness of the CCA of women who were less than 18 months since menopause.

CONCLUSION

Overall, these results demonstrate no significant effects of tibolone on either intima-media thickness or blood flow resistance in the carotid arteries in postmenopausal women. However, the results suggest that tibolone may have a positive effect on the vascular system if commenced within 18 months since menopause; this warrants further investigation.

Menopausal hot flushes revisited

Vasomotor symptoms are generally recognized as one of the most common symptoms, or signs, of the menopause, together with menstrual cycle changes. The etiology of hot flushes is unknown, although several mechanisms have been implicated. The reduction in hot flushes with estrogen replacement therapy suggests a hormonal etiology. However, the levels of estrogens do not appear to correlate with hot flushes. It seems more likely that the rate of change of plasma estrogen concentrations influences the thermoregulatory system via the hypothalamus. During the past few decades, remedies for the treatment of hot flushes have advanced from simple sedatives and purgatives to the use of ovarian extracts and, finally, to pharmacological estrogen preparations. In view of the contraindications and side-effects of estrogens and progestogens in postmenopausal women, however, there is a need to consider treatments other than hormone replacement for the relief of hot flushes.

Effects of tibolone and raloxifene on bone mineral density in osteopenic postmenopausal women

A randomized trial was conducted in osteopenic postmenopausal women to compare the efficacy of tibolone versus raloxifene on BMD of the lumbar spine and hip. Tibolone increased lumbar spine and total hip BMD to a statistically significantly greater extent than raloxifene after two years of treatment.

INTRODUCTION

Both tibolone, a selective tissue estrogenic activity regulator (STEAR), and raloxifene, a selective estrogen receptor modulator (SERM), are known to prevent postmenopausal bone loss. However, no head-to-head studies to compare the efficacy on bone have been performed.

METHODS

A double-blind, randomized trial was conducted in osteopenic postmenopausal women aged 60-79 years to compare the effects of tibolone 1.25 mg/day to raloxifene 60 mg/day on bone mineral density (BMD). Serum osteocalcin and serum type I collagen C-telopeptides were measured as biochemical markers of bone metabolism.

RESULTS

Three hundred and eight subjects were allocated to treatment. Both treatments significantly increased lumbar spine BMD, however the increase was significantly larger after tibolone treatment than after raloxifene treatment (at year 1: 2.2% versus 1.2%, p<0.01 and at year 2: 3.8% versus 2.1%, p<0.001). After 2 years of treatment, the increase in total hip BMD in the tibolone group was significantly larger than in the raloxifene group (p<0.05). Both treatments significantly reduced type I collagen C-telopeptides and osteocalcin levels when compared to baseline.

CONCLUSIONS

Tibolone 1.25 mg/day for 2 years prevents postmenopausal bone loss in older women and results in a larger increase of BMD both at the lumbar spine and hip than raloxifene.

Effects of tibolone on estrogen biosynthesis in the mammary tissue of postmenopausal monkeys

OBJECTIVE

To evaluate the long-term effects of tibolone on estrone sulfate (E1S)-sulfatase activity in breast tissue in a primate model (Macaca fascicularis) in comparison with conventional hormone therapies.

DESIGN

Ovariectomized female animals (n = 112) were randomized into five groups and treated for 2 years. Treatment included tibolone at 0.05 mg/kg (LoTib, n = 23) or 0.2 mg/kg (HiTib, n = 23), conjugated equine estrogens at 0.042 mg/kg (CEE, n = 24), CEE + medroxyprogesterone acetate at 0.167 mg/kg (CEE+MPA, n = 21), or placebo (controls, n = 21). E1S-sulfatase activity was evaluated by incubating homogenized breast tissue with [H]-E1S. Thin-layer chromatography was performed to separate the products estrone (E1) and estradiol (E2). Histomorphometry was performed to measure the amount of epithelial and fat tissue in the mammary gland.

RESULTS

Significantly more E2 than E1 was produced in all groups. E1S-sulfatase activity did not differ among the groups. E1S-sulfatase activity was highest in HiTib animals with less fatty breasts (5.9 fmol total estrogen/mg of protein/min; P < or =0.05) and lowest in HiTib animals with more fatty breasts (2.8 fmol total estrogen/mg of protein/min; P = 0.004 relative to less fatty breasts).

CONCLUSIONS

We conclude that tibolone had a differential effect on local estrogen biosynthesis in animals with high and low breast fat content. Therefore, breast tissue composition affects the steroidogenic response to hormonal treatment.

Tibolone and osteoporosis

BACKGROUND

We conducted a 5-year prospective, observational, controlled study to assess the effects of tibolone 1.25 mg/day on bone mineral density (BMD) in postmenopausal women with osteopenia or osteoporosis.

METHODS

The subjects were 420 women, an average of 66.4 years old, who had been postmenopausal between 8 and 19 years when enrolled in the study. Of the 420 women enrolled, 346 agreed to take tibolone for 5 years. The 74 who refused tibolone took only calcium/vitamin D supplements and served as the control group. BMD was measured in the lumbar spine and total hip region at baseline and annually by dual-energy X-ray absorptiometry (DXA).

RESULTS

At the first two follow-up visits, women taking tibolone had a significant increase in BMD at the spine (P < 0.001) and at the hip (P < 0.001) when compared to baseline values and when compared to BMD values for the control group, which decreased from baseline. In the final 3 years of the study, BMD values (spine and hip) continued to decrease in the control group and also tended to decrease in the tibolone group, but at the end of the fifth year, mean BMD in the tibolone group was still higher than BMD before the start of tibolone treatment (P < 0.05). Calculations showed that if women taking tibolone continued to lose BMD at the same rate as during the final 3 years of the study, after 11 years of tibolone treatment the average patient would have the same BMD as she had when treatment started.

CONCLUSION

This 5-year observational study provides evidence that tibolone is effective in increasing BMD in postmenopausal women with osteopenia and osteoporosis during the first 2 years of treatment, but because BMD starts to decline in the third year, it is vital that postmenopausal women start treatment with tibolone as early as possible, so that bone mineral density levels are kept high as long as possible.

Effects of tibolone on body composition in postmenopausal women: a 1-year follow up study

OBJECTIVE

We investigated the effects of 1-year tibolone treatment on body weight, body composition and indices of android obesity in postmenopausal women.

METHODS

Forty-four postmenopausal women participated in this open-label controlled study; mean age was 51.8+/-2.21 years and all women were menopausal for 3.8+/-1.40 years. Twenty-two of them started taking 2.5 mg tibolone (TIB) daily for 1 year, whereas the remaining 22 served as age-matched controls. All subjects underwent a structured interview, physical examination, body composition measurements performed by dual-energy X-ray absorptiometry (DXA) - Hologic QDR 4500 A, as well as bioelectrical body impedance analysis (BI) - Tanita TBF-215, Japan.

RESULTS

The TIB group did not significantly increase their weight (+0.4 kg), while the non-treated controls increased their mean weight by 1.4 kg (p=0.046). In the TIB group, DXA showed a non-significant body fat decrease by a mean of 0.5 kg and a non-significant lean mass increase by 0.8 kg, while in the control group, fat mass increased by 1.7 kg (p=0.032) and lean mass did not change. BI revealed that the TIB group had lost some fat ( approximately 0.6 kg, n.s.) and put some free-fat mass ( approximately 1.0 kg, p=0.048) without changes in total body water. The control group put on some fat ( approximately 1.1 kg, p=0.042) and lost some body water ( approximately 0.4 kg, n.s.).

CONCLUSION

Results from both methods of measuring body composition show a similar trend: a decrease in fat mass and an increase in lean mass in TIB treated subjects. From the body composition perspective, tibolone may be regarded as a preferential alternative to conventional hormonal therapy (HT) in postmenopausal women.

Sulfation of tibolone metabolites by human postmenopausal liver and small intestinal sulfotransferases (SULTs)

Sulfation is a major pathway in humans for the biotransformation of steroid hormones and structurally related therapeutic agents. Tibolone is a synthetic steroid used for the treatment for climacteric symptoms and postmenopausal osteoporosis. Sulfation inactivates the hydroxylated metabolites, 3alpha-hydroxytibolone (3alpha-OH-tibolone) and 3beta-hydroxytibolone (3beta-OH-tibolone), and contributes to the regulation of tissue responses to tibolone. We detected SULT1A1, SULT1A3, SULT1E1 and SULT2A1 mRNA expression by RT-PCR in postmenopausal liver and small intestine. Liver pool (n=5) SULT activities measured with tibolone substrates reflected COS-1 expressed SULT2A1 and SULT1E1 activities. Liver SULT2A1 activity (1.8 +/- 0.3 units/mg protein, n = 8, mean +/- SEM), and activities with 3alpha-OH-tibolone (0.6 +/- 0.1, n = 8) and 3beta-OH-tibolone (0.9 +/- 0.2, n = 8) were higher than SULT1E1 activities (<0.05, n = 10). SULT1E1 activities were low or not detected in many samples. Mean small intestinal activities were 0.03 +/- 0.01 with 3alpha-OH-tibolone and 0.04 +/- 0.01 with 3beta-OH-tibolone (n = 3). In conclusion, SULT2A1 is the major endogenous enzyme responsible for sulfation of the tibolone metabolites in human postmenopausal tissues. The results support the occurrence of pre-receptor enzymatic regulation of hydroxytibolone metabolites and prompt further investigation of the tissue-selective regulation of tibolone effects.

Effects of tibolone on bone quality in ovariectomized monkeys

OBJECTIVE

The purpose of this report is to examine the effects of two doses of tibolone on bone quality (bone biomarkers, bone density, and bone strength) in ovariectomized cynomolgus monkeys fed high-fat diets.

DESIGN

Ovariectomized cynomolgus monkeys were randomized into one of five treatment groups: placebo-treated control, tibolone (0.2 mg/kg/day), tibolone (0.05 mg/kg/day), conjugated equine estrogens (Premarin, 0.042 mg/kg/day), and conjugated equine estrogens plus medroxyprogesterone acetate (0.042 and 0.167 mg/kg/day, respectively). Bone quality was assessed by determining bone strength and density in vertebrae and femora collected after 24 months of treatment.

RESULTS

Monkeys treated for 24 months with tibolone had increased bone mineral density in the distal femur and improved biomechanical properties in the midshaft femur compared with placebo-treated ovariectomized monkeys, as did monkeys treated with conjugated equine estrogens with or without medroxyprogesterone acetate. No treatment effects were seen in lumbar vertebra bone density or strength. There was no significant difference between tibolone and estrogen on biomechanical properties of the femur.

CONCLUSION

These data show that tibolone is comparable to conjugated equine estrogens with or without medroxyprogesterone acetate in decreasing bone turnover and increasing bone strength in ovariectomized monkeys.

Tibolone: Clinical recommendations and practical guidelines

An international multidisciplinary panel of experts in the management of the menopause met at the 4th Amsterdam Menopause Symposium in October 2004 to determine the specific place of tibolone, a synthetic steroid with a unique clinical profile, within the wide range of currently available postmenopausal therapy options. The consensus was that tibolone is a valuable treatment option for women with climacteric complaints. As well as relieving vasomotor symptoms, tibolone has positive effects on sexual well-being and mood, and improves vaginal atrophy and urogenital symptoms. Prevention of bone loss with tibolone is comparable to that seen with estrogen therapy (ET) and estrogen/progestogen therapy (EPT). As tibolone rarely causes endometrial proliferation, no additional progestogen is required. It also has good tolerability, being associated with a low incidence of vaginal bleeding and of breast pain. Tibolone does not increase mammographic density. Absolute numbers of women at increased risk for breast cancer are estimated to be low or absent with both tibolone and ET, and the risk with tibolone should be significantly lower than that with EPT. Tibolone might therefore be preferable to EPT in certain women who have not been hysterectomised. Based on the evidence available, the panel proposed a number of subgroups of postmenopausal women with vasomotor symptoms in whom tibolone might have added value; these included women with sexual dysfunction, mood disorders, fibroids and urogenital complaints, as well as those with breast tenderness or high mammographic breast density with EPT use.

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.

A review of the effects of tibolone on the skeleton

Osteoporosis is a frequent condition, which can lead to significant morbidity and even to increased mortality, owing to its complications (i.e., the fractures). Several therapies, mostly antiresorbing agents such as oestrogens, antioestrogens (chiefly raloxifene), calcitonin and bisphosphonates, are recognised for the treatment of the condition. More recently, parathyroid hormone has been added to the armamentarium of therapeutic agents. However, except for oestrogens, no other therapy alleviates climacteric symptoms. There is, therefore, some room for a therapeutic agent dealing with both osteoporosis and menopausal symptoms. Tibolone might be such an agent. However, so far, no fracture data are available; all existing studies have shown a positive action of tibolone on bone mineral density. No study has been tailored to study the antifracture efficacy. The Long Term Intervention on Fractures with Tibolone (LIFT) study has been started with the aim at filling the gap between bone mineral density maintenance and bone fracture prevention. At the same time, this study should help to understand the similarities and differences between tibolone and oestrogens as far as long-term bone action and safety are concerned, and should particularly help to clarify a possible link between tibolone use and breast cancer.

Hormone replacement therapy update: who should we be prescribing this to now?

PURPOSE OF REVIEW

To summarize results from the Women's Health Initiative trial and other recent randomized placebo-controlled trials of hormone replacement therapy, which fundamentally changed our understanding of its risks and benefits.

RECENT FINDINGS

The Women's Health Initiative study for the first time provided evidence of harmful effects of hormone replacement therapy on the cardiovascular system and also confirmed significantly increased risk of breast cancer which was previously documented in a metaanalysis. Most recent studies indicate a particularly harmful effect of combined estrogen/progestin regimens in terms of increased breast cancer risk.

SUMMARY

The effects of hormone replacement therapy on coronary heart disease, stroke, venous thromboembolism, breast cancer, gallbladder, diabetes, cognitive function, health-related quality of life, colorectal cancer, osteoporosis and menopausal symptoms are discussed briefly. The emphasis is on providing concise clinical guidelines for hormone replacement therapy use in new circumstances. We also discuss some alternative therapeutic modalities for women who have menopausal symptoms, but contraindications for hormone replacement therapy.

Effect of tibolone on markers of cardiovascular disease risk in postmenopausal women undergoing hemodialysis: a pilot study

OBJECTIVE

To assess the effect of tibolone on markers of vascular risk in postmenopausal women who were receiving hemodialysis.

DESIGN

One-year open-label study.

SETTING

"Zvezdara" University Medical Center, Belgrade, Serbia.

PATIENT(S)

Twenty-eight postmenopausal women undergoing chronic hemodialysis.

INTERVENTION(S)

Fifteen women received tibolone 2.5 mg three times per week; 13 other women served as controls.

MAIN OUTCOME MEASURE(S)

Mean arterial pressure and weight were measured at baseline and at 6 and 12 months, and blood was collected for insulin, total cholesterol, low-density lipoprotein, high-density lipoprotein, triglycerides, lipoprotein(a), high-sensitivity C-reactive protein (hs-CRP), endothelin-1 (ET-1), vascular endothelial growth factor (VEGF), and markers of renal function.

RESULT(S)

Mean arterial pressure fell in the tibolone but not in the control group at 6 and 12 months versus baseline (mean [SD]: 93 [15] vs. 105 [11] mmHg and 94 [10] vs. 105 [11] mmHg, respectively). Weight, insulin, lipids, lipoprotein(a), hs-CRP, ET-1, VEGF, and renal function remained unchanged within each group, but high-density lipoprotein concentrations fell in the tibolone group after 12 months (1.2 [0.3] vs. 1.6 [0.6] mmol/L).

CONCLUSION(S)

The effects of tibolone on markers of vascular risk in postmenopausal women who are receiving hemodialysis and healthy women appear to differ. This should be taken into account when tailoring menopausal therapies to the specific requirements of each individual.

The menopause and HRT. Prevention and management of osteoporosis

Post-menopausal osteoporosis is characterized by increased fracture risk due to deficiencies in both the quantity and quality of bone. Assessing fracture risk involves combining clinical risk factors, including fall risks, with bone density testing. Treatment strategies are aimed at reducing fracture risk. General nutritional and lifestyle measures are appropriate for all women. Drug treatment is most clearly indicated in post-menopausal women at high current fracture risk. Treatment should also be considered for women at intermediate fracture risk, including those who have both low bone density and other risk factors for fracture. Whether there is practical clinical value in treating low-risk patients is much less clear. Non-pharmacological approaches addressing the consequences of fractures are integral parts of a comprehensive treatment programme. Reducing both the frequency and the effects of falls complements the efforts of treating osteoporosis to reduce the incidence of fractures and their important clinical consequences.

Pros and cons of existing treatment modalities in osteoporosis: a comparison between tibolone, SERMs and estrogen (+/-progestogen) treatments

Tibolone, selective estrogen receptor modulators (SERMs) like tamoxifen and raloxifene, and estrogen (+/-progestogen) treatments prevent bone loss in postmenopausal women. They exert their effects on bone via the estrogen receptor (ER) and the increase in bone mass is due to resorption inhibition. The effect of SERMs on bone mineral density is less than that with the other treatments, but the SERM raloxifene still has a positive effect on vertebral fractures. In contrast to tibolone and estrogens (+/-progestogen), SERMs do not treat climacteric complaints, whilst estrogen plus progestogen treatments cause a high incidence of bleeding. Estrogen plus progestogen combinations have compromising effects on the breast. Tibolone and SERMs do not stimulate the breast or endometrium. Unlike SERMs, tibolone does not possess antagonistic biological effects via the ER in these tissues. Estrogenic stimulation in these tissues is prevented by local metabolism and inhibition of steroid metabolizing enzymes by tibolone and its metabolites. SERMs and estrogen (+/-progestogen) treatments increase the risk of venous thromboembolism (VTE), whilst estrogen (+/-progestogen) combinations have unwanted effects on cardiovascular events. So far, no detrimental effects of tibolone have been observed with respect to VTE or cardiovascular events. The clinical profile of tibolone therefore has advantages over those of other treatment modalities. It is also clear that tibolone is a unique compound with a specific mode of action and that it belongs to a separate class of compounds that can best be described as selective, tissue estrogenic activity regulators (STEARs).

Effects of tibolone and conventional hormone replacement therapies on arterial and hepatic cholesterol accumulation and on circulating endothelin-1, vascular cell adhesion molecule-1, and E-selectin in surgically menopausal monkeys

OBJECTIVE

Menopause and aging are associated with a marked increase in the incidence of coronary heart disease as well as reductions in circulating estrogen, progestogen, and androgen levels. The synthetic compound tibolone and its metabolites have estrogenic, progestogenic, and androgenic characteristics. In the present study, we compared the effects of tibolone, estrogen replacement therapy, and estrogen plus progestogen replacement therapy on arterial and hepatic lipid accumulation and on circulating soluble adhesion molecule and endothelin-1 concentrations in surgically postmenopausal cynomolgus monkeys.

DESIGN

Animals were fed an atherogenic diet for 2 years while receiving either no hormone treatment (control, n = 31) or the following treatments at doses designed to mimic the human dose on a daily caloric intake basis: tibolone at 2.5 mg/day (HiTib, n = 31), tibolone at 0.625 mg/day (LoTib, n = 29), conjugated equine estrogens (CEE) alone at 0.625 mg/day (CEE, n = 29), or CEE plus continuous medroxyprogesterone acetate (MPA) at 2.5 mg MPA/day (CEE + MPA, n = 30).

RESULTS

Relative to the control group, iliac artery total cholesterol content was not different in the HiTib, LoTib, and CEE + MPA groups but was significantly lower in the group receiving CEE only (P < 0.05). In contrast, hepatic free cholesterol content was reduced in all treatment groups [HiTib (P < 0.01), LoTib (P < 0.05), CEE (P < 0.01), and CEE + MPA (P < 0.05)], whereas hepatic total and esterified cholesterol content were reduced in the HiTib, CEE, and CEE + MPA groups (all P < 0.05). HiTib and CEE groups had lower hepatic triglyceride levels per milligram of protein (P < 0.05). Iliac arterial cholesterol content was highly correlated with hepatic cholesterol content and with previously published histomorphometrically determined coronary artery atherosclerosis, supporting the use of the iliac artery as a surrogate for the coronary artery in the monkey. Circulating levels of soluble vascular cell adhesion molecule-1 were significantly reduced in the HiTib (P < 0.02) and CEE (P < 0.05) groups, whereas soluble E-selectin was reduced in the CEE group only (P < 0.01). Plasma endothelin-1 was significantly reduced in the LoTib (P < 0.05), CEE (P < 0.01), and CEE + MPA (P < 0.01) groups.

CONCLUSIONS

These results suggest that while tibolone caused marked depression of high-density lipoprotein cholesterol and a resultant twofold increase in the total plasma cholesterol/high-density lipoprotein cholesterol ratio, those effects did not result in exacerbation of iliac artery atherosclerosis, perhaps because of beneficial effects on vascular biology or hepatic metabolism.

Comparison of tibolone and conjugated equine estrogens effects on carotid artery atherosclerosis of postmenopausal monkeys

BACKGROUND AND PURPOSE

Tibolone is a tissue-specific compound that has favorable effects on bone and menopausal symptoms without stimulating endometrium or breast, but lowers concentrations of plasma high-density lipoprotein (HDL) cholesterol (HDLC). This study was designed to determine whether the HDL lowering with tibolone exacerbated common or internal carotid artery atherosclerosis and to evaluate tibolone treatment relative to conjugated equine estrogens (CEE) alone or in combination with medroxyprogesterone acetate (MPA).

METHODS

Carotid artery atherosclerosis was compared in groups of surgically postmenopausal cynomolgus monkeys treated with CEE, CEE+MPA, or either of 2 doses of tibolone versus untreated monkeys.

RESULTS

Despite a 30% to 52% lowering of HDLC with tibolone, there was no significant effect on carotid artery atherosclerosis. CEE and CEE+MPA, however, inhibited carotid artery atherosclerosis by approximately 60%.

CONCLUSIONS

In surgically postmenopausal cynomolgus monkeys, CEE and CEE+MPA inhibited common and internal carotid artery atherosclerosis. Despite the potentially adverse effects of tibolone on HDLC, tibolone did not exacerbate atherosclerosis.

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.

Effect of tibolone compared with sequential hormone replacement therapy on carbohydrate metabolism in postmenopausal women

OBJECTIVE

To investigate the effects of tibolone on carbohydrate metabolism, and to compare these effects with those of a sequential regimen of conjugated equine estrogens and medrogestone.

METHODS

This was an open-label, multicentre, comparative study. Seventy-two postmenopausal women were randomized to receive either tibolone 2.5 mg/day or conjugated equine estrogens 0.6 mg plus sequential medrogestone 5 mg (CEE/M) for six 28-day cycles. Carbohydrate metabolism was evaluated at baseline and after three and six cycles of treatment by an oral glucose tolerance test (OGTT). A blood sample was taken at 30, 60, 90 and 120 mm after glucose 75 mg dosing for determination of plasma glucose, insulin and connecting peptide (C-peptide) levels.

RESULTS

The changes from baseline of glucose, insulin and C-peptide area-under-the-curve (AUC) values were not statistically significant after 3 and 6 months of tibolone or CEE/M treatment. There was a small transitory decrease in HbA(1C) after three cycles of treatment with tibolone.

CONCLUSION

The effects of tibolone and CEE/M on carbohydrate metabolism were considered to have no clinical significance.

[Approach of menopause in women at risk for breast cancer]

The small but significant increase in risk of discovering breast cancer in women with hormone replacement therapy and the recent discussion of coronary benefit of this treatment have led many authors to insist on the necessity to evaluate the benefit/risks ratio before administration. This evaluation is particularly important for women that are already at high risk of breast cancer because of some genetic predisposition, family history or some benign breast diseases. In these cases, it is important to evaluate the absolute risk of breast cancer, to define the patient's needs more precisely, to specify menopausal symptoms; it is also important to evaluate the risk of osteoporosis, to review the various therapeutic possibilities, which are not only estrogen/progestin treatments (there are alternative treatments), and to give the patients honest information. Before obtaining the results of current trials, we are proposing here a pragmatic attitude and a decision algorithm to adopt a therapeutic attitude more easily which will be decided together by both patients and their physicians.

A comparison of tibolone and hormone replacement therapy on coronary artery and myocardial function in ovariectomized atherosclerotic monkeys

OBJECTIVE

Tibolone is used to prevent osteoporosis and to treat climacteric symptoms. The objectives of these studies were to measure and compare the effects of tibolone with hormone replacement therapy on coronary artery vascular reactivity and myocardial function and to relate these outcomes to treatment-induced plasma lipid/lipoprotein concentrations and atherosclerosis.

DESIGN

One hundred forty-eight adult ovariectomized cynomolgus monkeys were fed an atherogenic diet for 24 months while receiving one of five oral treatments: no treatment (control, n = 31); conjugated equine estrogens (CEE), given at the equivalent of 0.625 mg/day ( n = 27); CEE (same dose) plus medroxyprogesterone acetate (MPA), given at the equivalent of 2.5 mg/day ( n = 29); low-dose tibolone (LoTib; 0.625 mg/day equivalent, n = 30); or high-dose tibolone (HiTib; 2.5 mg/day equivalent, n = 31).

RESULTS

Quantitative coronary angiography showed that endothelium-mediated dilation was enhanced (17.5 +/- 5%, p = 0.002) in the CEE-treated group (but not other treatment groups) compared with the control. Both doses of tibolone and CEE reduced the incidence of dobutamine-induced ST-segment depression (LoTib: 33%, HiTib 25%, and CEE: 23%) compared to the control (79%) ( p = <0.05). Neither vascular reactivity nor dobutamine-induced myocardial ischemia were associated with treatment-induced changes in atherosclerosis or plasma lipid/lipoprotein concentrations.

CONCLUSIONS

Tibolone, unlike CEE, has no benefit for endothelium-mediated dilation. Despite these differences, both tibolone and CEE reduced the incidence of myocardial ischemia, whereas CEE+MPA had no effect. It is speculated that tibolone may have direct effects on the myocardium that protect against myocardial ischemia.

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

Although the minimal dose of 17beta-estradiol in hormone replacement regimens was originally considered to be 2 mg/day, it is now increasingly accepted that a lower dose of 1 mg/day is effective in protecting women from the detrimental effects of the menopause. A 1-year, multicentre, double-blind, randomised study was conducted in 214 healthy postmenopausal women in order to assess the effect of 17beta-estradiol (1 mg/day) continuously combined with dydrogesterone (5, 10 or 20 mg/day) in preventing bone loss. Bone mineral density (BMD) was evaluable in 177 women who completed the study. In all women, a statistically significant increase from baseline in lumbar vertebrae (L2-L4) BMD was seen after 6 months ( + 2.4%; p < 0.01); this increase was somewhat greater after 12 months ( + 3.6%; p < 0.01). Similar effects were seen in the hip. After 6 months, BMD in the femoral neck, Ward's triangle and trochanter had increased by 0.20% (not significant [n.s.]), 0.32% (n.s.) and 1.08% (p < 0.01), respectively, compared with baseline. Greater increases were again seen after 12 months ( + 1.16%, + 1.62% and + 2.83%, respectively), all of which were statistically significant (p < 0.01) compared with baseline. The change in BMD from baseline did not differ significantly between the three dydrogesterone dosages for either L2-L4 or hip. All dosages were well-tolerated and amenorrhoea was achieved in over 70%. In conclusion, 17beta-estradiol (1 mg/day) continuously combined with dydrogesterone (5, 10 or 20 mg/day) results in a significant increase in lumbar vertebrae and hip BMD in postmenopausal women. The lower dose of oestrogen and the avoidance of cyclical bleeding make this a particularly suitable regimen for the prevention and treatment of osteoporosis in older women.

Selective estrogen receptor modulators: from bench to bedside and back

OBJECTIVE

To provide a brief review of the history of the development of selective estrogen receptor modulators (SERMs), the current data assessing the effect of SERMs at the organ level, and the mechanism of action of these agents.

METHODS

All the pertinent medical literature was reviewed, and the effects of SERMs on various end-organs were summarized.

RESULTS

SERMs have been available for clinical use since the late 1960s. By the late 1980s, several SERMs had become available that influenced clinical practice. Multiorgan effects of these compounds include variable clinical efficacy for treatment of menopausal symptoms involving the central nervous system, variable effects on the genitourinary tract, and, in general, positive effects on serum lipid levels. SERMs seem to affect bone density positively, albeit to variable degrees, depending on the agent being used. The greatest effect of SERMs has been on the breast, and current SERMs seem to have efficacy for prevention of breast cancer as opposed to the controversial effect of estrogen on the breast. Disadvantages of SERMs include exacerbation of menopausal symptoms and, as with estrogen, an increased incidence of venous thrombosis and pulmonary emboli. SERMs act by modifying the configuration of the estrogen receptor. Effects at the gene transcription level seem to be tissue specific, a factor that likely accounts for the variability of clinical action seen.

CONCLUSION

SERMs are a viable option for treatment of various problems associated with menopause.

Biodegradable progesterone microsphere delivery system for osteoporosis therapy

The purpose of this study was to formulate and characterize a controlled-release biodegradable delivery system of progesterone for the treatment or prevention of osteoporosis. Microspheres of progesterone were formulated using copolymers of poly(glycolic acid-co-dl-lactic acid) (PGLA 50/50 and PGLA 15/85) and poly(L-lactic acid) (L-PLA) of similar molecular weight by the emulsion solvent evaporation technique. The effects of process variables, such as volume fraction, polyvinyl alcohol (PVA) concentration, polymer composition, and stir speed during preparation, on the yield, encapsulation efficiency (EEF), particle size distribution, in vitro release profiles of progesterone, and surface morphology of progesterone microspheres were investigated. Increasing the volume fraction from 9% to 22% increased the EEF without significantly increasing the yield; however, the rate of progesterone release from the microspheres decreased. Increasing the PVA concentration from 1% to 5% had no significant influence on the EEF, but the rate of progesterone release from microspheres increased. Polymer composition had no significant effect on the EEF, but had a significant effect on the particle size distribution, surface morphology, and release rate of progesterone from the microspheres. Stir speed did not have a significant influence on the EEF; however, stir speed influenced particle size distribution and the rate of progesterone release from microspheres of the same sieve-size range. The results suggest that controlled release of progesterone is possible by varying the different process variables, and that PGLA 50/50 provided the slowest release of progesterone. This should provide a means of delivering progesterone for months for the treatment or prevention of osteoporosis in postmenopausal women.

Tibolone, a steroid with a tissue-specific hormonal profile, completely prevents ovariectomy-induced bone loss in sexually mature rats

Tibolone (Org OD 14) is a synthetic steroid with combined estrogenic, progestagenic, and androgenic properties and behaves as a tissue-specific steroid. In the current study, we determined the effects of a 4-week treatment with different doses of tibolone on estrogen deficiency-induced bone loss in mature 3-month-old rats. As a reference, 17alpha-ethinyl estradiol (EE2) was used. The frequency of administration, once or twice a day, was also studied. Bone parameters were determined in sham operated controls, ovariectomized (OVX) controls and OVX-treated rats. Bone loss was assessed by peripheral quantitative computed tomography directly and by quantitative Roentgen densitometry after defatting to exclude influence of fat changes. Femoral bone geometric parameters, plasma osteocalcin level, and urinary deoxypyridinoline/creatinine ratio were also determined. Ovariectomy caused a significant decrease in trabecular bone mineral density in the distal metaphyseal part of the femur using both methods, whereas no change in cortical bone density was found. Trabecular bone loss was prevented in a dose-dependent manner by tibolone (250, 1000, and 4000 microgram/rat/day) when given once or twice daily. EE2 also prevented trabecular bone loss but its efficacy was dependent upon the frequency of dosing. Both tibolone and EE2 induced a significant reduction in the urinary deoxypyridinoline/creatinine ratio and plasma osteocalcin level. Tibolone and EE2 had no effect on other femoral bone parameters except a reduction in femoral length. In conclusion, treatment with tibolone for 4 weeks prevented OVX-induced bone loss by suppressing both bone resorption and bone turnover in a similar way as EE2. However, the frequency of dosing is more important for EE2 than for tibolone. Tibolone acts in this animal model for postmenopausal bone loss as an estrogen agonist on bone.

Prevention of postmenopausal bone loss at lumbar spine and upper femur with tibolone: a two-year randomised controlled trial

OBJECTIVE

To examine the effects of tibolone on bone mineral density and its concurrent safety and subject acceptability.

DESIGN

Prospective randomised controlled study.

SETTING

Centre for Metabolic Bone Disease, Hull.

POPULATION

Forty-seven healthy post-menopausal women aged 50-57 years with normal bone mineral density at lumbar spine.

METHODS

Bone mineral density was assessed every 24 weeks at lumbar spine and proximal femur using dual energy X-ray absorptiometry.

RESULTS

The bone mineral density of the tibolone treated subjects tended to increase while those of the controls tended to fall. The higher densities in the tibolone group were significant at lumbar spine from week 24 (P = 0.002) and at the trochanter from week 72 (P = 0.014). The lower bone densities in the controls were significant at Ward's Triangle and femoral neck at week 96 (P < 0.0001), and at lumbar spine from week 24 onwards (P < 0.05). Between-treatment analysis indicated that, by the 96th week, the bone densities at all sites in the tibolone group were significantly different from those in the control group. At the lumbar spine the differences were highly significant throughout the study (P < 0.0004). Four women receiving tibolone withdrew from the study due to unacceptable adverse events. Two women withdrew from the control group. There was no significant difference between the groups in the number of subjects suffering adverse experiences. Vaginal bleeding occurred in seven women, all from the tibolone treated group, resulting in one withdrawal from the study.

CONCLUSION

Tibolone is thus an effective and well-tolerated alternative to oestrogen in the prevention of osteoporosis with its beneficial effects being most apparent at the lumbar spine.

Decrease of serum endothelin levels with postmenopausal hormone replacement therapy or tibolone

Endothelin is the most potent vasoconstrictor peptide known to date. Hormone replacement therapy (HRT) with estrogen reduces plasma endothelin levels. We measured endothelin in 51 postmenopausal patients before and during HRT. Patients were randomly allocated to receive either oral tibolone, oral or transdermal 17 beta-estradiol. A group of comparable volunteers served as controls. After 24 months, endothelin levels decreased in all treatment groups: tibolone, 18.2%; oral 23.1%; transdermal, 20.8%. Endothelin levels increased in the controls by 36.6% (p < 0.01). Tibolone decreases endothelin levels to a similar degree as conventional estrogen-progestogen-replacement therapy. These data provide another potential mechanism supporting the cardioprotective effects of tibolone.

Urinary bone resorption markers in monitoring treatment of symptomatic osteoporosis

We have studied the clinical usefulness of urinary bone resorption markers in postmenopausal women with symptomatic osteoporosis. The study design is a randomised double-blind placebo controlled study, in which the subjects were daily treated for 24 months either with a hormone analogue (2.5 mg Livial, generic name Tibolone, Organon, Amsterdam, Holland) plus 800 mg calcium (n = 14, age 63+/-5 years, range 52-68 years), or with placebo plus 800 mg calcium (n = 19, age 66+/-7 years, range 50-75 years). The laboratory methods for urinary bone resorption markers were enzyme immunoassays (EIA) for urinary pyridoline (PYD) and deoxypyridoline crosslinks (DPD), and for cross-linked N-telopeptides of Type I Collagen (NTx), and an HPLC assay for urinary hydroxyproline (HOP). All the urine assay results were calculated per mmol creatinine. All the resorption markers decreased during the two-year study period in both groups. The Z scores (discriminating power, i.e. ability of the different tests to distinguish the hormone treated subjects from the placebo treated subjects) for HOP and PYD were rather low: 0.06-1.52 for HOP and 0.68-1.47 for PYD. The differences between the two treatment groups were statistically significant for DPD at 12 and 24 months of treatment (P = 0.0471 and P = 0.0466, respectively), the Z scores ranging 0.45-1.90. NTx showed the most prominent decrease from the beginning of the study especially in the hormone treatment group: the differences between the two treatment groups were statistically highly significant for NTx already at 6 months of treatment (P = 0.0015), and the Z scores remained high ranging 2.11-3.82 throughout the two-year study period. Dual X-ray absorptiometry (DXA) of the lumbar spine and femoral neck did not show statistically significant differences between the two treatment groups throughout the two-year study period. After 2 years there was, however, a significant increase in bone density both in the spine (+ 6.6%, P = 0.0002) and in the femoral neck (+ 3.4%, P = 0.0389) in the women with hormone treatment. In the control group a significant increase (+ 5.1%, P = 0.0012) in the spine, whereas a non-significant decrease (-1.5%, n.s.) in the femoral neck was observed. We suggest that measurement of urinary cross-linked peptides derived from Type I collagen (NTx and DPD) might be a useful biochemical method of observing the positive clinical effect (i.e. reduction in bone resorption) following hormone replacement therapy in postmenopausal fracture patients.

Tibolone: a review

Tibolone appears to be at least as efficacious as other forms of hormonal replacement therapy (HRT) on climacteric symptoms. It does not cause withdrawal bleeding when used in women with at least 1 year of amenorrhea. It is, therefore, not indicated in perimenopause because it may cause irregular bleeding. The androgenic action of tibolone may have a two-fold benefit: on the one hand, it may help depression and libido more than other forms of HRT, while, on the other hand, it may improve some lipid parameters such as Lp(a), and triglycerides. However, this androgenic action, may also be responsible for the reduction of HDL cholesterol, that may thus reduce the beneficial effect of tibolone on lipids. It is estimated that only 30% of cardiovascular risk protection of HRT is due to improvement of classical lipids parameters while a great role is played by the direct effect of estrogen on vessels. Tibolone, as well as estrogen, has been shown to induce peripheral vasodilatation and also has a direct effect on vascular reactivity thus increasing peripheral blood flow with no changes in blood pressure or cardiac output. Tibolone seems to exert a similar effect as other forms of HRT on markers of bone metabolism and bone mass, but no data is yet available on fracture prevention.

A 3-year study of prevention of postmenopausal bone loss: conjugated equine estrogens plus medroxyprogesterone acetate versus tibolone

The aim of this study was to investigate the effects of tibolone in the prevention of postmenopausal bone loss over 3 years, and to compare these with the effects of sequential hormone replacement therapy. Forty early postmenopausal women were randomized to a 21-day regimen of conjugated equine estrogens (CEE, Premarin) plus sequential medroxyprogesterone acetate (MPA, Prodafem), or tibolone (Livial) daily. In total, 36 women completed 12 months and were considered for the intent-to-treat analysis, 34 completed 24 months and 23 completed 36 months. Main drop-out reasons were: lost to follow-up (n = 9) and minor side-effects (n = 4). Bone mineral density was measured at baseline and after 6, 12, 24 and 36 months, using dual-energy X-ray absorptiometry at the lumbar spine and the upper femur (neck, trochanter, total hip). In both groups, bone loss was prevented. Treatment with tibolone demonstrated significant increases in bone density at the spine (+4.6%; p < 0.01), at the total hip (+3.2%; p < 0.01) and at the trochanter (+4.5%; p < 0.01), whereas the CEE/MPA group showed a non-significant increase of bone mineral density at the lumbar spine (+2.6%) but no increases at the hip. Between-group differences in bone mineral density changes were significant (p < 0.05) for the total hip and the trochanter at 36 months. This increase of bone mineral density was not accompanied by changes in insulin-like growth factor-I (IGF-I) or insulin-like growth factor binding protein-3 (IGFBP-3) in either group. Osteocalcin, alkaline phosphatase and urinary ratios of hydroxyproline/creatinine and calcium/creatinine significantly decreased in both groups. In conclusion, sequential CEE/MPA prevented cortical and trabecular bone loss, with a transient increase of bone mineral density only during the first 6 months. Tibolone not only prevented cortical and trabecular bone loss, but further increased bone mineral density at the lumbar spine and at the hip throughout the 3 years of treatment, suggesting a sustained positive effect on bone mass.

Differential impact of conventional oral or transdermal hormone replacement therapy or tibolone on body composition in postmenopausal women

OBJECTIVE

To compare the effects on body composition and body weight of tibolone vs two different sequential oral or transdermal oestrogen-progestogen hormone replacement therapies versus no therapy.

PATIENTS AND METHODS

One hundred postmenopausal women were assigned to a control group (n = 26), or randomized to 1) tibolone (TIB) 2.5 mg/day (n = 28), 2) oral oestradiol 2 mg/day (PO) plus sequential dydrogesterone 10 mg/day for 14 of 28 days per cycle (n = 26), or 3) transdermal oestradiol patch (TTS) releasing 50 micrograms/day plus oral sequential dydrogesterone 10 mg/day for 14 of 28 days per cycle (n = 20). Body composition was measured at the base-line and every 6 months for 2 years by DXA (Hologic QDR 1000 W).

RESULTS

Total body fat mass increased (P < 0.05) in controls (+3.6 +/- 1.5%) and in TTS treated (+4.7 +/- 2.2%), but not in PO (-1.2 +/- 2.4%) and TIB (-1.6 +/- 2.2%) treated subjects. This increase in total fat mass in controls and TTS treated women was mostly due to an increase in fat mass of the trunk (P < 0.05), but not legs. As a result, a redistribution of body fat to the trunk occurred in controls, TTS and TIB, but not in PO treated women (P < 0.05). Total lean body mass decreased (P < 0.02) in controls (-1.7 +/- 0.7%) and PO (-1.4 +/- 0.6%) but not in TTS (+0.3 +/- 0.8%) and TIB (+0.4 +/- 0.5%) treated subjects.

CONCLUSIONS

The menopause is associated with an increase in total body fat and a decline in lean body mass. Oral oestradiol/dydrogesterone and tibolone prevent total body fat changes, whereas transdermal oestradiol/oral dydrogesterone and tibolone prevent the lean mass changes. Furthermore, oral oestradiol/dydrogesterone prevents the shift to a central, android fat distribution.

Bone mineral density and broadband ultrasound attenuation with estrogen treatment of postmenopausal women

The purpose of the current study was to determine the changes in lumbar spine, hip, and calcaneus bone mineral density (BMD), and in calcaneus broadband ultrasound attenuation (BUA) in early menopausal women and to assess the effects of estrogen replacement therapy (ERT) on bone mass at these sites over a 2-yr period. Fifty-three Caucasian women who were at least 6 mo postmenopausal were divided into two groups based on estrogen use. Twenty-one women, average age 53.0 +/- 0.6 yr and 2.9 +/- 0.3 yr since menopause, had been receiving estrogen in combination with progesterone for at least 6 mo prior to enrollment in the study. Thirty-two women, average age 52.7 +/- 0.8 yr and 2.8 +/- 0.3 yr since menopause, had never received ERT. During the 2-yr study, women not receiving ERT had significant decreases in BMD of the spine -2.3 +/- 0.6%, femoral neck -2.2 +/- 0.8%, and calcaneus -4.7 +/- 0.9%, and in BUA of the calcaneus -14.3 +/- 1.8%. ERT prevented the decreases in BMD at the spine +0.4 +/- 0.6% and calcaneus -2.3 +/- 1.1%, but did not prevent a significant decrease in bone mass at the femoral neck -1.9 +/- 0.8% and BUA at the calcaneus -17.8 +/- 3.2%. Neither group had significant decreases in total hip BMD. This study demonstrates again that ERT prevents the menopause-associated decreases in spine BMD. However, in this group of women, ERT did not prevent loss in femoral neck BMD or BUA. The results suggest that women being treated with estrogen for maintenance of BMD in early menopause need to be monitored to ensure efficacy of therapy, especially in the maintenance of femoral neck BMD.