The effect of various regimens of hormone replacement therapy on mammographic breast density

OBJECTIVES: To evaluate the effect of three distinct hormone replacement therapy regimens on mammography. METHODS: 121 postmenopausal women who had never received or were past users of hormone replacement therapy were studied prospectively. Women with an intact uterus were randomly allocated either to conjugated equine estrogens 0.625 mg plus medroxyprogesterone acetate 5 mg (CEE/MPA, n=34) or to 17beta-estradiol 2 mg plus norethisterone acetate 1 mg (E(2)/NETA, n=35). Hysterectomized women received CEE 0.625 mg (CEE, n=25). Women who either declined or did not qualify for treatment served as controls (n=27). 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: No increase in breast density was identified in any of the women in the control group. Two women (8%) in the CEE group showed an increase in breast density. Four women (11.8%) in the CEE/MPA and 11 women (31.4%) in the E(2)/NETA group revealed an increase in breast density. No woman in the therapy groups showed an involution of fibroglandular tissue while seven women (25.9%) in the control group exhibited involution of breast parenchyma. CONCLUSIONS: Our study suggests that hormone replacement therapy may suspend breast involution but does not increase breast density in the majority of patients. In the minority of patients who show a density increase, the magnitude of this increase varies according to the regimen employed.     

Serum androgen levels and insulin resistance in postmenopausal women: association with hormone therapy, tibolone and raloxifene

OBJECTIVE: To assess endogenous androgen and insulin resistance status in postmenopausal women receiving continuous combined hormone therapy (HT), tibolone, raloxifene or no therapy. METHODS: A total of 427 postmenopausal women aged 42-71 years were studied in a cross-sectional design. Among them 84 were taking HT (46 women conjugated equine estrogens 0.625 mg; medroxyprogesterone acetate, 5 mg, CEE/MPA; and 38 women 17beta-estradiol 2 mg; norethisterone acetate 1 mg, E2/NETA); 83 were taking tibolone 2.5 mg; 50 were taking raloxifene HCl 60 mg; and 210 women were not receiving any therapy. Main outcome measures were FSH, LH, estradiol, total testosterone, SHBG, free androgen index (FAI), Delta4-Androstendione (Delta4-A), Dehydroepiandrosterone sulphate (DHEAS) and HOMA insulin resistance index (HOMA-IR). RESULTS: In women not on hormone therapy smoking and older age was associated with lower DHEAS levels. FAI values increased linearly with increasing BMI. Age and BMI were positive determinants of HOMA-IR, while no association was identified between endogenous sex steroids and insulin resistance. CEE/MPA therapy was associated with higher SHBG, lower FAI and lower HOMA-IR values compared to women not on therapy (age and BMI-adjusted SHBG: CEE/MPA 148.8 nmol/l, controls 58.7 nmol/l, p < 0.01; age-adjusted FAI: CEE/MPA 0.8, controls 3.2, p < 0.05; age-adjusted HOMA-IR: CEE/MPA 1.3, controls 2.6, p < 0.05). On the contrary, E2/NETA treatment had no effect on these parameters. Women on tibolone had lower SHBG, higher FAI and similar HOMA-IR values compared to controls (age and BMI-adjusted SHBG: 24.1 nmol/l, p < 0.01; FAI: 6.0, p < 0.05; HOMA-IR: 2.3, p = NS). Raloxifene users did not exhibit any difference with respect to sex steroids and HOMA-IR levels. CONCLUSIONS: CEE/MPA users had lower free testosterone and improved insulin sensitivity. Tibolone on the other hand associated with higher free testosterone, while raloxifene did not relate to any of these parameters.     

Postmenopausal uterine bleeding profiles with two forms of continuous combined hormone replacement therapy.

OBJECTIVE: This study was designed to compare the bleeding profiles of conjugated equine estrogens 0.625 mg in combination with 2.5 mg medroxyprogesterone acetate (Prempro; CEE/MPA group), the most widely prescribed continuous combined hormone replacement therapy (CCHRT) in the United States, with 17beta-estradiol 1 mg combined with 0.5 mg norethindrone acetate (Activella; E(2)/NETA group), a newly available CCHRT preparation, over a 6-month period. DESIGN: This study was a prospective, randomized, multicenter, double-blind, controlled trial. A total of 438 healthy postmenopausal women were randomized and received treatment (Activella n = 217, Prempro n = 221). Each woman recorded bleeding diaries daily. Total cholesterol, triglycerides, and endometrial biopsies were obtained at screening and end-of-trial visits. RESULTS: The more favorable bleeding profile was found in the E(2)/NETA (Activella) group. The differences in bleeding patterns were most marked in the first 3 months of treatment in women who were 1-2 years from last menses, with no bleeding in 71.4% vs. 40.0%; ( p = 0.005) and with no bleeding and no spotting in 54.8% vs. 17.1%; (p = 0.001). Triglycerides fell by 8.5% in the E(2)/NETA group and increased by 11.7% in the CEE/MPA group (p < 0.001). Total cholesterol declined by 9.1% and 6.9%, respectively. CONCLUSION: The most important factor in the continuation of HRT is uterine bleeding. E(2)/NETA has significantly less bleeding than the most commonly prescribed CCHRT CEE/MPA, therefore; E(2)/NETA should be associated with improved continuation rates. The patient taking E(2)/NETA will receive effective treatment for her menopausal symptoms with less bleeding.     

Progestins oppose the effects of estradiol on the endothelin-1 receptor type B in coronary arteries from ovariectomized hyperlipidemic rabbits

OBJECTIVE: Progestins may be associated with the adverse cardiovascular outcomes observed with estrogen plus progestogen therapy, but the mechanism is not resolved. In this study we examined the effect of 17beta-estradiol (E2) alone and in combination with two progestins on the endothelin-1 (ET-1) system in coronary arteries. DESIGN: Watanabe heritable hyperlipidemic rabbits were treated orally with either E2 (4 mg/d), medroxyprogesterone acetate (MPA) (10 mg/d), norethisterone acetate (NETA) (2 mg/d), E2 + MPA, E2 + NETA, or placebo for 16 weeks (n=10 in each group). Coronary arteries were used for mRNA and myograph analyses. RESULTS: E2 alone but not in combination with MPA or NETA increased ETB mRNA expression in coronary arteries. Accordingly, E2 alone but not in combination with MPA or NETA reduced the maximal contraction to ET-1, and the reduction was sustained after ETA but not after ETB blockade. E2 reduced preproendothelin-1 mRNA expression; however, this effect was not blunted by MPA or NETA. ETA and ET-converting enzyme-1 mRNA expression was unaffected by treatment. CONCLUSIONS: The data suggest that long-term E2 treatment selectively attenuates ET-1-induced vasoconstriction, possibly by increasing ETB gene expression in rabbit coronary arteries and that this effect is abolished by the two progestins investigated. This observation may help to explain how progestins oppose the supposed beneficial effects of estrogen on the arterial wall.     

Hormone replacement therapy, C-reactive protein, and fibrinogen in healthy postmenopausal women

Objective: To investigate short-term and long-term effects of combined hormone replacement therapy (HRT) on C-reactive protein (CRP) and fibrinogen plasma concentrations in healthy postmenopausal women. Methods: In this cross-sectional study 241 healthy postmenopausal women were enrolled. A total of 81 women were receiving the following treatments for 3 months; transdermal 17β-estradiol (17β-E₂)+medroxyprogesterone acetate (MPA) (n=21), oral 17β-E₂+norethisterone acetate (NETA) (n=27), and conjugated equine estrogens (CEE)+MPA (n=33). The same combined therapies were implemented in another 58 women for 12 months; transdermal 17β-E₂+MPA (n=10), oral 17β-E₂+NETA (n=16), and CEE+MPA (n=32). Control group included 102 healthy postmenopausal women not receiving HRT. The effect of the type and the duration of HRT regimens on plasma levels of CRP, fibrinogen and lipids were investigated. Results: Median CRP concentrations were significantly higher in women receiving oral 17β-E₂+NETA (P=0.037) and CEE+MPA (P=0.0001) for 3 months than in women taking the same types of HRT for 12 months and of those were not on HRT. Median CRP levels were similar in women taking transdermal 17β-E₂+MPA for 3 and 12 months, compared with controls. Fibrinogen levels were not different between nonusers and any group of HRT users. Conclusions: These elevated levels of CRP, which appears very recently as a crucial marker for cardiovascular disease, may be responsible for the early increased cardiovascular risk after starting oral combined HRT. But this increased risk in the early period seems to decrease with long-term use. Transdermal 17β-E₂+MPA had insignificant effect on CRP both in short-term or in long-term use.     

Transvaginal sonographic monitoring of the uterine effects of raloxifene and a continuous combined replacement therapy in postmenopausal women

OBJECTIVE: To study the effect of 17beta-estradiol+norethisterone acetate and raloxifene on the endometrium and uterine volume in postmenopausal women. METHODS: Patients were randomly assigned to 17beta-estradiol 2 mg+norethisterone acetate 1mg (E2+NETA) daily (n=90) or raloxifene HCl 60 mg (Evista) daily (n=43). Transvaginal sonography was done at baseline and at 6, 12 and 18 months, and at 6 and 12 months in-patients treated with E2+NETA and EVISTA respectively. Patients were asked to record bleeding-spotting episodes. Whenever required patients were referred for hysteroscopy+/-biopsy of the endometrium. RESULTS: Patients under E2+NETA had a higher bleeding-spotting incidence (48.6%) compared with EVISTA (7.7%). Endometrial thickness increased significantly under E2+NETA as compared with baseline; however, at end point thickness reverted to baseline values. Evista had a non-stimulatory effect on the endometrium. Changes in uterine volume were not statistically significant. CONCLUSIONS: Both treatment regimens provided comparable uterine safety. However, raloxifene exhibited a more favorable safety profile on the uterus as expressed in the bleeding-spotting incidence and the effect on endometrial thickness and uterine volume. Transvaginal sonography appears to be a dependable method for monitoring the effect of treatment on the uterus.     

Effect of hormone replacement therapy on serum levels of tumor markers in healthy postmenopausal women

Objective: The effect of hormone replacement therapy (HRT) on serum levels of tumor markers is barely defined. The aim of this study was to evaluate the effect of HRT on levels of tumor markers CA 125, CA 15-3, CA 19-9, CEA and -FP. Methods: Retrospective analysis of prospectively collected data in healthy postmenopausal women under oral estrogen replacement therapy (ERT, conjugated equine estrogen (CEE) 0.625 mg (n=21) or estradiol 2 mg (n=31)), and continuous combined estrogen and progesterone regimen (HRT, CEE 0.625 mg plus medroxyprogesterone acetate 2.5 mg (n=34) or estradiol 2 mg plus norethisterone acetate 1 mg (n=37)). One hundred and twenty-three healthy women among a sampled population of 654 postmenopausal patients with complete records, initial normal tumor marker levels, and at least 1 year of follow-up were included into the study. Tumor markers were measured with 1-year interval. Results: Fifty-two (41.5%) patients were under ERT and 71 (58.5%) were under combined HRT. The number of months since menopause, age and age at menopause did not influence tumor marker levels at first admission. All of the tumor marker levels were in normal range after 1 year. Pretreatment CA 125 II, CA 15-3 and CEA levels were significantly low (median and range) 5.0 (1.0–11.8) versus 7.45 (1.0–18.1) U/ml for CA 125, 27.05 (7.3–37.5) versus 32.6 (12.5–37.9) U/ml for CA 15-3, 0.88 (0.58–2.8) versus 1.34 (0.53–2.41) ng/ml for CEA in women with hysterectomy when compared to women without hysterectomy. There was no effect of ERT on CA 125 II, CA 19-9, CEA and -FP levels. E2 led to a significant decrease in post-treatment CA 15-3 levels [32.9 (8.1–34.9) vs. 18.1 (6.7–31.4); P<0.001]. CA 125 levels were only significantly reduced in hysterectomised women using continuously combined HRT [7.9 (2.6–17.7) vs. 5.6 (1.3–19.2) for CEE+MPA, and 7 (1–18.1) vs. 5.8 (1.8–17.4) for E2+NETA; P<0.05]. There was a small, but not significant, increase in CA 125 levels in women under ERT. Conclusion: Although there was a statistically significant decrease in CA 15-3 levels in current E2 and E2+NETA users, and a decrease in CA 125 levels in combined regimens, this change is clinically not relevant in healthy postmenopausal women. This data will be useful for the caregivers in the management and follow-up of cancer survivors who preferred replacement therapy as the only treatment of their postmenopausal symptoms.     

Effects of continuous combined conjugated estrogen/medroxyprogesterone acetate and 17beta-estadiol/norethisterone acetate on lipids and lipoproteins

OBJECTIVES: Various estrogen/progestogen combinations used in hormonal replacement therapy (HRT) have been reported to influence lipid and lipoprotein fractions differently. This motivated a comparative study where the two continuous combined regimens most commonly used in Sweden during the 1990s have been studied regarding effects on lipid profile. METHODS: In a 1-year prospective, double-blind study, 62 post-menopausal women were randomized to conjugated estrogen (CE), 0.625 mg, and medroxyprogesterone acetate (MPA), 5 mg, or 17beta-estradiol (E2), 2 mg, and norethisterone acetate (NETA), 1 mg. Serum concentrations of lipids and lipoproteins were measured at baseline and after 1 year of treatment. RESULTS: Both treatment groups significantly lowered the lipoprotein(a) (Lp(a)) levels. The CE/MPA group showed no significant changes in total cholesterol (TC), high-density (HDL) and low-density lipoprotein (LDL), but a significant increase of triglyceride (TG) levels. The E2/NETA group developed a significant lowering of total cholesterol, HDL, and LDL, but no significant changes of TG levels. The magnitude of change in serum concentrations of total cholesterol, HDL and TG differed significantly between the two treatment groups. CONCLUSIONS: Continuous combined treatment with CE/MPA and E2/NETA equally lowered Lp(a), an important risk factor for cardiovascular disease in women. Apart from this, the two treatments produced different effects on lipids and lipoproteins, findings that are more delicate to interpret.     

Association of serum complement (C3, C4) and immunoglobulin (IgG,IgM) levels with hormone replacement therapy in healthy post-menopausal women

BACKGROUND: Recently published data suggest that hormone replacement therapy (HRT) may increase cardiovascular risk during the early months of therapy. Activation of the immune system is known to be involved in several types of cardiovascular disease. In this cross-sectional study, serum C3, C4, IgG and IgM levels were evaluated in healthy post-menopausal women receiving two different short-term HRT regimens, and in untreated women. METHODS: Serum C3, C4, IgM and IgG levels were assessed in 18 women receiving transdermal 17beta-estradiol (50 micro g/day) + continuous oral medroxyprogesterone acetate (MPA; 2.5 mg/day), in 56 women taking oral conjugated equine estrogen (CEE; 0.625 mg/day) + continuous MPA, and in 80 control women not receiving HRT. RESULTS: The mean serum C3 level was significantly higher in women using oral CEE + MPA than in women receiving transdermal 17beta-estradiol + MPA, and those not on HRT (P = 0.02 and P < 0.001 respectively). Furthermore, women taking oral CEE + MPA had significantly higher mean levels of C4 compared with untreated women (P < 0.01). IgG and IgM levels were similar among women either of the two HRT regimens and between women not on HRT. CONCLUSIONS: Oral HRT may be involved in the development of cardiovascular disease through inflammatory mechanisms, as suggested by increased serum levels of C3 and C4.     

Effects of tibolone and combined 17beta-estradiol and norethisterone acetate on serum C-reactive protein in healthy post-menopausal women: a randomized trial

BACKGROUND: Serum C-reactive protein (CRP) is an independent risk factor for the development of cardiovascular diseases in healthy post-menopausal women. Oral unopposed and progestin-combined 17beta-estradiol (E(2)) increase serum CRP in post-menopausal women. The aim of this study was to compare the effects of tibolone, a steroid with estrogenic, androgenic or progestogenic properties, with a combination of E(2) and norethisterone acetate (E(2) + NETA) on serum CRP levels in healthy post-menopausal women. METHODS: A total of 139 post-menopausal women (mean age: 55 years, range 44-48) was randomly assigned to receive tibolone 1.25 mg/day (n = 52), tibolone 2.5 mg/day (n = 39) or E(2) 2 mg/day plus NETA 1 mg/day (n = 48) for 2 years. Serum CRP was measured at baseline and at 6, 12 and 24 months. RESULTS: Both doses of tibolone and E(2) + NETA increased serum CRP by a similar extent as soon as 6 months with a sustained effect over the 24 month treatment period. For example, after 6 months of treatment, serum CRP increased by a median of +106% (P < 0.001), +89% (P < 0.05) and +139% (P < 0.001) for tibolone 1.25 mg/day, tibolone 2.5 mg/day and E(2) + NETA respectively. CONCLUSIONS: Tibolone and E(2) + NETA significantly increase serum CRP levels in healthy post-menopausal women to a comparable extent. Relationships between induced elevated CRP levels with tibolone and E(2) + NETA and cardiovascular events require further studies.     

Quality of life assessment in a chemoprevention trial: fenretinide and oral or transdermal HRT

BACKGROUND: Oral conjugated equine estrogen (CEE) and medroxyprogesterone acetate (MPA) relief menopause symptoms, but may increase breast cancer risk, while the effects of transdermal estradiol (E2) and MPA are less known. In previous studies, fenretinide decreased second breast malignancies in premenopausal but not in postmenopausal women, suggesting a hormone-sensitizing effect. We have evaluated the quality of life through a self-administered questionnaire during a randomized study of oral CEE or transdermal E2 and fenretinide or placebo. METHODS: A total of 226 postmenopausal women were randomly assigned to either CEE 0.625mg/day and placebo (n=55), or CEE and fenretinide 100mg/bid (n=56), or E2, 50microg/day and placebo (n=59), or E2 and fenretinide (n=56) for 12 months. Sequential MPA 10mg/day was added in all groups. Treatment effects were investigated using a validated questionnaire, the Menopause Quality of Life questionnaire (MENQOL). RESULTS: Oral CEE and transdermal E2 have a comparable activity in reducing menopausal symptoms (p=ns). Both routes ameliorate significantly the symptoms after 1 year of treatment (p<0.0001). Fenretinide does not modify the effects of hormonal replacement therapy. CONCLUSIONS: Oral CEE and transdermal E2 have similar effect on menopausal symptoms relief. The choice of the best estrogen replacement therapy (ERT) route should be decided based on a careful analysis of all the clinical aspects of every subject, considering that transdermal therapy may have a safer effect on the cardiovascular system.     

Effective bleeding control and symptom relief by lower dose regimens of continuous combined hormone replacement therapy: A randomized comparative dose-ranging study

Objectives: We compared two different continuous combined hormone replacement therapy (HRT) regimens of estradiol valerate (E₂V) and medroxyprogesterone acetate (MPA) with a combination of micronized estradiol (E₂) and norethisterone acetate (NETA) to determine bleeding pattern, control of climacteric symptoms, lipid profile, endometrial and general safety in a 1-year multicenter study. Methods: 440 postmenopausal women were randomized to three treatment groups to receive: 1 mg E₂V+2.5 mg MPA; 1 mg E₂V+5 mg MPA; or 2 mg of E₂+1 mg NETA. After the first 6 months, the E₂V dose was increased to 2 mg in both E₂V/MPA groups. Information on bleeding was recorded on diaries by the women and intensity of climacteric symptoms was assessed using VAS scales. Physical and laboratory examinations, endometrial biopsy and vaginal ultrasonography were performed at baseline and follow-up visits. Results: Significantly fewer bleeding days were experienced in the first 3 months by women taking E₂V/MPA compared with women taking E₂/NETA. When the dose of E₂V was increased in the E₂V/MPA groups, an increase in maximum bleeding intensity was observed in the group receiving 2.5 mg of MPA, but not in the group taking 5 mg of MPA. All dose combinations effectively relieved climacteric symptoms and beneficial effects on the lipid profile were seen after 6 months in all groups. Tolerability and endometrial safety were good and no cases of hyperplasia were observed. More women discontinued treatment prematurely in the E₂/NETA group compared with either of the E₂V/MPA groups. The overall continuation rates ranged from 70 to 86%. Conclusions: These results confirm that lower dose combinations of continuous combined HRT are usually sufficient to control symptoms or avoid breakthrough bleeding. However, if higher E₂V dose is needed for symptom control, it should be combined with the higher dose of progestin (5 mg) to avoid bleeding disturbances. Flexible treatment regimens should be available for individualized HRT.     

The effects of 17 beta-oestradiol plus dydrogesterone compared with conjugated equine oestrogens plus medroxyprogesterone acetate on lipids, apolipoproteins and lipoprotein(a)

OBJECTIVE: To compare the effects of 17 beta-oestradiol plus dydrogesterone with conjugated equine oestrogens plus medroxyprogesterone acetate on serum lipids, apolipoproteins and lipoprotein(a) in postmenopausal women. METHODS: A multi-centre, prospective, randomised, double-blind, comparative one-year study in 362 healthy postmenopausal women aged 39-74 years with an intact uterus. Fasting blood samples were taken at baseline and after 28 and 52 weeks of treatment. Participants received daily oral treatment with continuous combined 1 mg micronised 17 beta-oestradiol/5 mg dydrogesterone (E/D: n=180) or 0.625 mg conjugated equine oestrogens/5 mg medroxyprogesterone acetate (CEE/MPA: n=182). RESULTS: Significant differences between the two groups after 52 weeks were observed for total cholesterol (E/D: -1.7%; CEE/MPA: -7.3%), LDL-cholesterol (E/D: -4.5%; CEE/MPA: -11.3%), HDL-cholesterol (E/D: +15.3%; CEE/MPA: +7.5%), triglycerides (E/D: +9.8%; CEE/MPA: +16.6%), VLDL-triglycerides (E/D: -3.3%; CEE/MPA: +10.0%), lipoprotein(a) (E/D: 0.0%; CEE/MPA: -25.2%) and for the ratio apolipoprotein B/LDL-cholesterol (E/D: +0.9%; CEE/MPA +5.9%). CONCLUSIONS: E/D and CEE/MPA differ in their anti-atherogenic effects on lipids and lipoproteins. This however can not easily be translated to differences in clinical cardiovascular outcomes.     

No increase in C-reactive protein levels during intranasal compared to oral hormone therapy in healthy post-menopausal women

BACKGROUND: Inflammation plays an important role in the development of atherosclerotic disease. Oral post-menopausal hormone therapy increases serum C-reactive protein (CRP) levels. This study compared the effects of intranasal and oral administration of 17beta-estradiol (E2) combined with norethisterone acetate (NETA) on markers of inflammation in healthy post-menopausal women. METHODS: Ninety healthy post-menopausal women (age 56.6 +/- 4.7 years) participated in this 1-year trial. After computerized block randomization, they daily received, in a double-blind fashion, either intranasal E2/NET [175 microg/275 microg (n = 47)] or oral E2/NETA [1 mg/0.5 mg (n = 43)]. Concentrations of high sensitivity CRP and adhesion molecules were measured at baseline and after 12, 24 and 52 weeks of treatment. RESULTS: CRP levels were increased (P = 0.001) in the oral but not in the intranasal group. The increase in the oral group was highest at week 12 (64.9%) and was larger (P < 0.01) compared with the non-significant increase (8.6%) found in the intranasal group. Both groups showed decreases (P < 0.001) in soluble vascular cell adhesion molecule (sVCAM), soluble intracellular adhesion molecule (sICAM) and sE-selectin. The decreases were larger (P < 0.01) in the oral than in the intranasal group. CONCLUSION: Intranasal E2/NET therapy did not significantly increase CRP levels, in contrast to the increase observed in the oral E2/NETA treatment group. Both intranasal and oral therapy lowered plasma concentrations of adhesion molecules, however, more so in the oral group.     

Effects of four different regimens of hormone replacement therapy on hemostatic parameters: a prospective randomized study

OBJECTIVE: To compare the effects of four different regimens including oral and transdermal formulations with or without progestins on the hemostatic system in a prospective randomized fashion. METHODS: Eighty-eight women were randomized to four groups receiving continuous transdermal estradiol 50 microg/day (tE2), oral conjugated equine estrogen 0.625 mg/day (CEE 0.625 mg), oral conjugated equine estrogen 0.625 mg/day plus medroxyprogesterone acetate 2.5 mg/day (CEE 0.625 mg/MPA 2.5 mg), or oral 2 mg 17-beta estradiol combined with 1 mg norethistrone acetate (E2/norethistrone). The hysterectomized patients received only estrogen, and the remaining women received the estrogen plus progesterone combination regimens. As a marker of hemostatic system fibrinogen, tissue plasminogen activator (tPA), and plasminogen activator inhibitor-1 (PAI-1) levels were measured initially, and after 1 and 6 months of therapy. RESULTS: The treatment groups were well matched for baseline characteristics including age, height, weight, body mass index, and systolic and diastolic blood pressures. During the study period fibrinogen levels were below the baseline values in all groups. However, the decrease was only statistically significant in patients treated with oral 0.625 mg/day CEE. tPA levels were decreased significantly by tE2, CEE 0.625 mg, and CEE 0.625 mg/MPA 2.5 mg. PAI-1 levels were decreased significantly by CEE 0.625 mg, and CEE 0.625 mg/MPA 2.5 mg. When the effects of the four different regimens were compared using percentage changes from the baseline, no significant difference was found among the treatment groups. CONCLUSION: One of the treatment regimens resulted in a more coagulable state. Oral therapy with CEE decreased the levels of all parameters, and MPA did not impair this beneficial effect, except for in fibrinogen. Transdermal therapy had a minimal effect. No significant difference was noted among the four regimens.     

Effects of two continuous hormone therapy regimens on C-reactive protein and homocysteine

OBJECTIVE: To compare the effects of two continuous hormone therapy (HT) regimens on the cardiovascular risk markers, C-reactive protein (CRP) and homocysteine. DESIGN: A prospective study in which 43 postmenopausal women were randomly assigned to either tibolone 2.5 mg/day (n = 20) or 0.625 mg/day conjugated equine estrogens (CEE) plus continuous medroxyprogesterone acetate (MPA) 5 mg/day (n = 23). Serum levels of CRP, homocysteine, vitamin B12, and folate were determined before and during 12 weeks of therapy. RESULTS: C-reactive protein levels were increased by tibolone (76%; P < 0.001) and CEE+MPA (81%; P < 0.001). Neither tibolone nor CEE+MPA had any significant effect on homocysteine levels, but there was a significant difference between the effects of treatment over time (P = 0.046). Both tibolone and CEE+MPA reduced vitamin B12 levels (11%; P < 0.001, and 8%; P < 0.01, respectively), but had no statistically significant effect on folate levels. Individual changes in homocysteine levels were negatively associated with changes in vitamin B12 levels (r = -0.68; P < 0.01) after tibolone therapy. CONCLUSION: Both tibolone and CEE plus MPA increased CRP levels and reduced levels of vitamin B12. Neither therapy had any significant effect on homocysteine levels. Further long-term studies into the effect of HRT on these markers, and the relationship to cardiovascular disease risk, are required.     

Effects of tibolone and hormone replacement therapy on the breast of cynomolgus monkeys

OBJECTIVE: To measure the effects of 2 years of treatment with tibolone on the breasts of cynomolgus macaques (Macaca fascicularis) in comparison with conventional hormone replacement therapy. DESIGN: Ovariectomized cynomolgus macaques were randomized into five groups and treated for 2 years. Groups included controls (n = 31) and four drug treatments, including tibolone at 0.05 mg/kg (LoTIB, n = 30) or 0.2 mg/kg (HiTIB, n = 31), conjugated equine estrogens at 0.042 mg/kg (CEE, n = 28), or CEE + medroxyprogesterone acetate (MPA) at 0.167 mg/kg (CEE + MPA, n = 29). Endpoints included histologic, histomorphometric, and immunohistochemical assessment of the mammary gland. RESULTS: Tibolone did not cause stimulation of the breast in contrast to distinct proliferative responses of the breast to CEE and CEE + MPA, as measured by increases in breast epithelial tissue area and expression of the proliferation marker Ki67 in breast epithelial cells. Tibolone at the higher dose increased progesterone receptor expression in the breast relative to controls, indicating partial estrogen-agonist activity, but without induction of proliferation. Progesterone receptor expression was also induced by CEE. CONCLUSIONS: Tibolone may have an advantage over conventional hormone replacement therapy because it does not stimulate proliferation in the breast. This lack of mammotrophic effect may reflect a lower risk for promotion of breast cancer.     

Effects of estradiol and norethisterone on lipids, insulin resistance and carotid flow

OBJECTIVES: To evaluate the lipid profile, insulin resistance and vasomotricity, and the interaction between these factors, in postmenopausal women receiving hormone therapy. METHODS: A prospective, randomized, double-blind study was carried out in which 77 postmenopausal women received one of the three treatment regimens: (A) 2mg oral micronized estradiol (E2) (n=25); (B) 2mg oral E2+1mg oral norethisterone acetate (NETA) (n=28); or C) placebo (n=24), daily for 6 months. Evaluations were carried out at baseline and at the end of treatment on lipid and lipoprotein profiles, homeostasis model assessment of insulin resistance (HOMA-IR) and pulsatility index (PI) of the internal carotid artery by Doppler ultrasonography. RESULTS: Mean increases of 15.6% and 2.4% and a reduction of 6.4% in high-density lipoprotein (HDL) levels were found for the E2, E2+NETA and placebo groups, respectively. Reductions of 9.5% and 3.7% and an increase of 12.1% in low-density lipoprotein (LDL), and reductions of 20.0% and 3.8% and an increase of 28.8% in the LDL:HDL ratio were found for the E2, E2+NETA and placebo groups, respectively (p<0.001 in all cases). Insulin levels and HOMA-IR decreased 12.8% and 12.3% in the E2 group and increased 12.9% and 16.0% in the E2+NETA group (p<0.05), respectively. Carotid PI following treatment was 1.18+/-0.23, 1.38+/-0.20 and 1.41+/-0.21 for the E2, E2+NETA and placebo groups, respectively (p=0.0006). CONCLUSIONS: Oral estrogen therapy led to an improvement in lipid profile, insulin resistance and carotid blood flow, which was cancelled when NETA was associated.     

Conjugated estrogen plus medroxyprogesterone does not impair blood rheological properties in hypertensive postmenopausal women

OBJECTIVES: Hypertension and estrogens are both prothrombotic. We used the microchannel method to investigate whether hormone replacement therapy (HRT) with conjugated equine estrogen (CEE) plus medroxyprogesterone acetate (MPA) affects blood flow through the microchannels in hypertensive postmenopausal women being treated with antihypertensive drugs and in normotensive postmenopausal women. METHODS: Sixty-two consecutive postmenopausal women were randomly assigned to a hypertensive HRT group (n=16), hypertensive control group (n=15), normotensive HRT group (n=16) and normotensive control group (n=15). Each HRT group received CEE 0.625 mg plus MPA 2.5 mg daily orally for 12 months. Both hypertensive groups were being treated with antihypertensive drugs before the study. Microvascular blood flow was assessed on the basis of blood passage time, the time required for 100 microl of whole blood to pass through a cylinder, was determined before and 12 months after the start of HRT by the microchannel method (micro channel array flow analyzer). RESULTS: CEE plus MPA therapy did not change blood passage time in any of the groups. Microscopic observation showed that the whole blood passed smoothly through the microchannels in every group. CONCLUSIONS: CEE plus MPA therapy may not impair blood flow through the microchannels in hypertensive postmenopausal women receiving antihypertensive drugs or in normotensive postmenopausal women. However, administration of CEE plus MPA to postmenopausal women with hypertension warrants caution against the occurrence of thromboembolic events.     

Prevention of postmenopausal bone loss with long-cycle hormone replacement therapy

OBJECTIVE: Postmenopausal bone loss and osteoporotic fractures can be prevented by hormone replacement therapy (HRT). However, opposed HRT may increase the risk of breast cancer above that associated with estrogen alone and in non-hysterectomized women estrogen substitution alone increases the risk of uterine cancer, which triggered renewed interest in long-cycle HRT regimens (estrogen replacement therapy with progesterone-free intervals up to 6 months). The effects on bone of such long-cycle HRT regimens are unknown. The objective of the present study was to compare the effects on bone and the endometrium of long-cycle HRT and conventional HRT. METHODS: Seventy-three healthy non-hysterectomized postmenopausal women were randomized to either conventional HRT (estradiol (E2) 2 mg/d during 12 days, E2 2 mg/d plus 1 mg/d of norethisterone acetate (NETA) during 10 days, E2 1 mg/d for 6 days) or long-cycle HRT treatment (two cycles with E2 2 mg/d during 28 days, followed by one cycle of conventional HRT and repeated every 3 months). Primary endpoint was the change in bone mineral density (BMD) at the lumbar spine (LS) over 24 months. RESULTS: BMD at LS increased significantly versus baseline in both treatment groups (conventional HRT +3.8 +/- 0.6%, long-cycle HRT +3.3 +/- 0.5%, p < 0.0001 for both) with no significant difference between treatment groups over 24 months. Similar significant BMD increases versus baseline were observed at the femoral neck, while biochemical markers of bone turnover (osteocalcin and deoxypyridinoline) were significantly decreased over 24 months. There were no endometrial or breast related adverse events reported. CONCLUSION: Long-cycle HRT may be a valid alternative to conventional HRT with regard to protection against postmenopausal bone loss.