New evidence regarding hormone replacement therapies is urgently required transdermal postmenopausal hormone therapy differs from oral hormone therapy in risks and benefits

Controversies about the safety of different postmenopausal hormone therapies (HTs) started 30 years ago and reached a peak in 2003 after the publication of the results from the Women Health Initiative (WHI) trial and the Million Women Study (MWS) [Writing group for the women's health initiative investigations. Risks and benefits of estrogen plus progestin in healthy postmenopausal women. JAMA 2002;288:321-33; Million women study collaborators. Breast cancer and hormone-replacement therapy in the million women study. Lancet 2003;362:419-27]. The single HT formulation used in the WHI trial for non hysterectomized women-an association of oral conjugated equine estrogens (CEE-0.625 mg/day) and a synthetic progestin, medroxyprogesterone acetate (MPA-2.5 mg/day)-increases the risks of venous thromboembolism, cardiovascular disease, stroke and breast cancer. The MWS, an observational study, showed an increased breast cancer risk in users of estrogens combined with either medroxyprogesterone acetate (MPA), norethisterone, or norgestrel. It is unclear and questionable to what extent these results might be extrapolated to other HRT regimens, that differ in their doses, compositions and administration routes, and that were not assessed in the WHI trial and the MWS. Significant results were achieved with the publication of the WHI estrogen-only arm study [Anderson GL, Limacher M, Assaf AR, et al. Effects of conjugated equine estrogen in postmenopausal women with hysterectomy: the Women's Health Initiative randomized controlled trial. JAMA 2004;291:1701-1712] in which hormone therapy was reserved to women who had carried out hysterectomy. What emerged from this study will allow us to have some important argument to develop.     

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.     

The effect of low-dose conjugated equine estrogens and cyclic MPA on bone density

OBJECTIVE: to compare the effect of 0.3 and 0.625 mg conjugated equine estrogens on bone mineral density (BMD) in a private practice setting. METHODS: postmenopausal women interested in hormone replacement therapy were prescribed either 0.3 or 0.625 mg conjugated equine estrogens daily with 10 mg medroxyprogesterone acetate days 1-12 of the month. All women were given calcium citrate 1000 mg/day and vitamin D 400 IU/day. DEXA bone mineral density studies of the spine and hip were performed at baseline and 1 year. RESULTS: there was no significant difference in BMD at the spine, the trochanter or the femoral neck compared with baseline in either the 0.625 or 0.3 mg group. The mean percent increase in BMD for the 0.3 versus 0.625 mg group was: spine 2.6 versus 3.8%, femoral neck 1.8 versus 1.5%, and trochanter 0.5 versus 2.6%. CONCLUSION: both the 0.625 mg dose and the 0.3 mg dose of conjugated equine estrogens preserved BMD at the spine and hip over one year in early postmenopausal women who were also given cyclic medroxyprogesterone acetate, calcium citrate and vitamin D.     

WHI and aftermath: looking beyond the figures

In contrast to the preliminary results of the WHI conjugated equine estrogen plus medroxyprogesterone acetate arm published 2 years ago, the final results from that arm as well as preliminary data from the conjugated equine estrogen-only arm showed that the panic over hormone treatment for menopausal women was unjustified. Moreover, the data for women younger than 60-years-old was even more reassuring. WHI was a study on elderly women starting hormones under the assumption that it may confer cardioprotection. The results of WHI should not be generalized and should not be a reason to withhold hormones in symptomatic perimenopausal or early post-menopausal women who could benefit from that therapy.     

Raloxifene reduces procarboxypeptidase U, an antifibrinolytic marker. A 2-year randomized, placebo-controlled study in healthy early postmenopausal women

OBJECTIVE: The aim of this study was to compare the long-term effects of two dosages of raloxifene with oral hormone therapy (HT; conjugated equine estrogens combined with medroxyprogesterone acetate) on procarboxypeptidase U. DESIGN: In a randomized, double-blind, placebo-controlled, 2-year study, 95 healthy, nonhysterectomized, early postmenopausal women received either daily raloxifene 60 mg (n = 24), raloxifene 150 mg (n = 23), HT (conjugated equine estrogens 0.625 mg + medroxyprogesterone acetate 2.5 mg, n = 24), or placebo (n = 24). At baseline and after 6, 12, and 24 months, fasting plasma procarboxypeptidase U concentrations were measured. RESULTS: Six months of treatment with raloxifene 60 mg and raloxifene 150 mg were associated with significant decreases in plasma procarboxypeptidase U concentrations, which were sustained after 12 and 24 months. Raloxifene 60 mg: t = 0, 619 +/- 89 U/L (mean +/- SD); t = 6, 574 +/- 87 U/L; t = 12, 571 +/- 96 U/L; t = 24, 568 +/- 92 U/L; ANCOVA versus placebo, P = 0.026. Raloxifene 150 mg: t = 0, 608 +/- 67 U/L; t = 6, 580 +/- 73 U/L; t = 12, 578 +/- 70 U/L; t = 24, 562 +/- 61 U/L; ANCOVA versus placebo, P = 0.039. No significant changes were found in the HT group. CONCLUSION: Long-term treatment with raloxifene reduced procarboxypeptidase U plasma concentrations.     

Effects of long-term hormone replacement and of tibolone on choline acetyltransferase and acetylcholinesterase activities in the brains of ovariectomized,cynomologus monkeys

We examined long-term effects of low and high doses of tibolone, conjugated equine estrogens, and conjugated equine estrogens plus medroxyprogesterone acetate on choline acetyltransferase and acetylcholinesterase activities within different regions of the brain in cynomologus monkeys. All treatments were administered for 2 years. None of the treatments produced significant increases in either choline acetyltransferase or acetylcholinesterase in any of eight brain regions analyzed. In contrast, treatment with conjugated equine estrogens plus medroxyprogesterone acetate, but not conjugated equine estrogens alone, produced significant reductions in both choline acetyltransferase and acetylcholinesterase in the medial septum/diagonal band of Broca compared with untreated controls. Treatment with tibolone also resulted in significant reductions in both choline acetyltransferase and acetylcholinesterase in the medial septum/diagonal band of Broca, and this effect was dose-related. These findings are the first to report the effects of long-term therapies used by postmenopausal women on cholinergic measures in the primate brain. The findings are consistent with recent reports in rats, and suggest that any positive effects of long-term estrogen or hormone replacement therapy on cognitive processes are probably not due to significant effects on choline acetyltransferase or acetylcholinesterase activities.     

A comparison of therapy continuation rates of different hormone replacement agents: a 9-month retrospective,longitudinal analysis of pharmacy claims among new users

OBJECTIVE: To estimate the rate of therapy continuation among women using six different hormone replacement therapies (HRTs). DESIGN: A retrospective, longitudinal analysis of pharmacy claims data was conducted for 7,120 women who were new users of six HRT regimens. Continuation rates of therapies were examined at the end of the 9-month period. In addition, the odds ratio of continuation for each product was determined using a logistic model, which controlled for the potential influence of a patient's age and a provider's age, gender, specialty, and geographical location. RESULTS: Treatment continuation rates at the end of the 9-month period were significantly higher among patients prescribed oral 1 mg norethindrone acetate/5 microgram ethinyl estradiol (EE) (femhrt, Pfizer Inc, New York, NY, USA) compared with other HRT regimens. Patients prescribed 1 mg norethindrone acetate/5 microgram EE were 52% more likely to continue therapy compared with patients prescribed 0.625 mg conjugated equine estrogens/2.5 mg or 5 mg medroxyprogesterone acetate (Prempro, Wyeth, Madison, NJ, USA). Significantly higher rates of therapy continuation were seen in women aged 55 years or older, those who did not switch HRT during the analysis, those who received care in the central and northeast regions of the United States, and those who were seen by obstetricians/gynecologists (v primary care physicians) or female (v male) providers. CONCLUSIONS: The higher rates of treatment continuation seen with newer continuous combined HRTs, such as 1 mg norethindrone acetate/5 microgram EE, may lead to improved long-term compliance and, therefore, better protection against osteoporosis in postmenopausal women.     

Substitution of transdermal estradiol during oral estrogen-progestin therapy in postmenopausal women: effects on hypertriglyceridemia

OBJECTIVE: We investigated effects of changing from oral estrogen to transdermal estradiol on the lipid and lipoprotein profile of postmenopausal women who developed hypertriglyceridemia (serum concentrations exceeding 150 mg/dL) during estrogen-progestin therapy. DESIGN: Sixty-one postmenopausal Japanese women receiving 0.625 mg of conjugated equine estrogen plus 2.5 mg of medroxyprogesterone acetate daily for 12 months had developed serum triglyceride concentrations exceeding 150 mg/dL after 12 months of treatment. Thirty-six of them, chosen randomly for study, were assigned at random to either a group that continued this oral regimen or another that changed to transdermal estradiol while continuing 2.5 mg of oral medroxyprogesterone acetate for the next 3 months (n = 18 for each). Blood lipids were compared between groups. RESULTS: Serum concentrations of triglyceride and very-low-density lipoprotein triglyceride decreased significantly after changing to transdermal estradiol (triglyceride, from 226.0 +/- 43.9 to 110.5 +/- 44.1 mg/dL, P < 0.01). No changes were seen in concentrations of low-density lipoprotein cholesterol or high-density lipoprotein cholesterol. CONCLUSION: Changing to transdermal estradiol may improve triglyceride metabolism in women who developed hypertriglyceridemia during oral estrogen-progestin therapy, with minimal effect on cholesterol profiles.     

A 5-year study on the effect of hormone therapy, tibolone and raloxifene on vaginal bleeding and endometrial thickness

OBJECTIVES: To study the effect of standard and low-dose estrogen-progestin therapy (EPT), tibolone and raloxifene on the incidence of vaginal spotting/bleeding and endometrial thickness over a 5-year period. METHODS: Seven hundred eighty-six postmenopausal women were studied in an open prospective design. Vaginal spotting/bleeding and endometrial thickness as assessed by transvaginal ultrasonography was compared between six categories of women over a 5-year period: three categories in women on continuous combined estrogen-progestin therapy, one category under tibolone, one category under raloxifene and one under no treatment. More specifically, women received tibolone 2.5 mg (N = 204), raloxifene HCl 60 mg (N = 137), conjugated equine estrogens 0.625 mg/medroxyprogesterone acetate 5mg (N = 122), 17beta-estradiol 2mg/norethisterone acetate 1mg (N = 58), 17beta-estradiol 1mg/norethisterone acetate 0.5mg (N = 76) or no therapy (controls, N = 189). Women with suspected endometrial pathology were referred for hysteroscopy. RESULTS: Bleeding/spotting incidence was highest among standard dose EPT users (conjugated equine estrogens 0.625 mg/medroxyprogesterone acetate 5mg: 40.1%, 17beta-estradiol 2mg/norethisterone acetate 1mg: 44.8%, p < 0.001 compared to controls). Low-dose EPT associated with lower incidence of spotting/bleeding (34.1%). The incidence under tibolone and raloxifene was 22.5% and 2.9%, respectively, while 3.2% of women not receiving therapy reported vaginal spotting/bleeding. Mean endometrial thickness was not significantly affected in any of the groups studied. The drop-out rate due to spotting/bleeding was higher in the two higher dose EPT regimens. After logistic regression analysis, age at baseline was the only significant predictor of subsequent spotting/bleeding (b = -0.25, S.E. = 0.09, p = 0.006), while menopausal age and pre-treatment serum FSH had marginal significance. CONCLUSIONS: EPT, tibolone and raloxifene do not appear to associate with significant changes in endometrial thickness in the majority of cases. The low-dose EPT regimen associated with a decreased incidence of unscheduled spotting/bleeding compared to the standard dose regimens. Tibolone expressed a favorable endometrial profile, as seen in its effect on unscheduled spotting/bleeding and mean endometrial thickness. Raloxifene associated with the lowest incidence in S/B and the lowest drop-out rate.s.     

A comparative study of two hormone replacement therapy regimens on safety and efficacy variables

Objective: To assess the effect of tibolone on endometrial safety, plasma estradiol concentrations, lipid metabolism and climacteric symptoms in comparison to sequential conjugated equine estrogens and medroxyprogesterone acetate in postmenopausal women. Methods: In a randomised, open-label, 6-cycle, group-comparative study, the effects on the aforementioned parameters were studied with tibolone 2.5 mg/day (N = 13) continuously, and with conjugated equine estrogens 0.625 mg/day continuously, combined with medroxyprogesterone acetate 5 mg/day (N = 11) (CEE/MPA) sequentially, during 12 days of each 28-day cycle. Within-group statistical analysis was performed with Student's t-test for paired samples, whereas between-group statistics were performed using the Student's t-test for independent groups. Results: Cytological evaluation revealed no endometrial stimulation in either group. In the tibolone group, there were no effects on estradiol levels, whereas in the CEE/MPA group, an increase in total and non-SHBG-bound estradiol plasma levels was reported. In the tibolone group, there were significant decreases in plasma total cholesterol, triglycerides, HDL-cholesterol and VLDL-cholesterol, whereas no significant changes in LDL-cholesterol and IDL-cholesterol were reported. In the CEE/MPA group there were significant decreases in plasma total cholesterol, HDL-cholesterol and LDL-cholesterol, whereas there were no significant changes in triglycerides, IDL-cholesterol and VLDL-cholesterol. Climacteric symptoms, particularly vasomotor episodes, decreased similarly in both groups. Conclusions: Both tibolone and CEE/MPA were safe with respect to effects on the endometrium and both treatments induced changes in the plasma profiles of certain lipid and lipoprotein parameters. However, the overall clinical implications of these changes are unknown. Finally, both regimens were equally effective in the treatment of climacteric symptoms     

Different effects of oral conjugated equine estrogens and transdermal estrogen on undercarboxylated osteocalcin concentration in postmenopausal women

OBJECTIVE: Undercarboxylated osteocalcin (ucOC) is a sensitive marker of vitamin K status, and triglyceride (TG) has been shown to be the main transporter of vitamin K. In the present study, we examined the difference between ucOC concentrations in postmenopausal women receiving hormone therapy (HT) with oral conjugated equine estrogens (CEE) and transdermal estradiol (TE2). We also examined the associations of ucOC concentration with estradiol concentration and TG. DESIGN: Ninety-two postmenopausal women were recruited for this study. Serum concentrations of ucOC, intact osteocalcin, estradiol, and TG were measured before and after 12 months of HT. Forty-six women received oral administration of 0.625 mg of CEE and 2.5 mg of medroxyprogesterone acetate daily, and 46 women received transdermal administration of 50 mug of 17beta-estradiol twice weekly and 2.5 mg of medroxyprogesterone acetate daily. RESULTS: The ucOC concentration in women during HT with oral CEE was significantly (P < 0.01) lower than that in women during HT with TE2. Serum estradiol concentrations during HT with CEE showed a significant inverse correlation with ucOC concentrations and the ratio of ucOC/OC during HT (P < 0.05 and P < 0.01, respectively). In addition, the serum ucOC concentration in women with an increased percentage of change in TG was significantly (P < 0.01) lower than that in women with a decreased percentage of change in TG during HT with oral CEE. CONCLUSION: The effect of HT with TE2 on ucOC concentration in women is weaker than the effect of HT with oral CEE. Suppression of ucOC concentration in postmenopausal women during HT with oral CEE might be associated with the effect of vitamin K through increased TG induced by oral CEE.     

The effect of low dose hormone therapy on mammographic breast density

OBJECTIVES: To evaluate the effect of two standard and one low dose continuous hormone therapy regimens on mammography. METHODS: One hundred and thirty-two non-hysterectomized postmenopausal women were randomly allocated either to conjugated equine estrogens 0.625 mg plus medroxyprogesterone acetate 5 mg (CEE/MPA, n=38), 17beta-estradiol 2 mg plus norethisterone acetate 1 mg (E2/NETA, n=44) or 17beta-estradiol 1 mg plus norethisterone acetate 0.5 mg (low E2/NETA, n=50). Treatment was continuous and the study period lasted 12 months. Main outcome measures were the changes according to Wolfe classification between baseline and 12-month mammograms. RESULTS: Five (13.2%) women in the CEE/MPA group showed an increase in breast density. Fourteen (31.8%) women on E2/NETA and 6 (12.2%) on low E2/NETA treatment revealed an increase in breast density. No woman exhibited an involution of fibroglandular tissue. CONCLUSIONS: Different hormone therapy regimens have a variable impact on breast density probably depending on the steroid used. Low dose hormone therapy associates with significantly lesser increase in breast density.