Standard and Low-dose Hormone Therapy for Postmenopausal Women—Focus on the Breast

[Menopause hormone treatment in practice. Postmenopausal women management: CNGOF and GEMVi clinical practice guidelines]

Menopause Hormonal Treatment (MHT) was initially developed to correct the climacteric symptoms induced by postmenopausal estrogen deficiency. In non-hysterectomized women, MHT combines estrogens and a progestogen, the latter opposing the negative impact of estrogen on endometrial proliferation. In France, and contrary to the USA and Northern European countries, MHT mainly combines 17β-estradiol, which is the physiological estrogen produced by the ovary, and progesterone or its derivative, dihydrogesterone. France has been a pioneer in the development of cutaneous administration routes (gel or transdermal patch) for estradiol, allowing better metabolic tolerance and a reduction of the risk of venous thromboembolism compared to the oral route. The choice of the doses as well as the treatment regimen is underpinned by tolerance as well as acceptance and compliance. The risk of breast cancer, which is one of the main risks of MHT, is higher with estro-progestogen combinations than with estrogens alone ; the preferential use of progesterone or dihydrogesterone being likely to limit the excess risk of breast cancer associated with MHT at least for duration of treatment of less than 5 to 7 years. The question of the optimal duration of MHT remains an issue and must take into account the initial indication of treatment as well as the benefit-risk balance, which is specific to each woman. Continuation of MHT is conditioned by the benefit-risk balance, which must be evaluated regularly, but also by the evolution of symptoms when MHT is stopped as well as menopause-related health risks or induced by MHT. After stopping MHT, it is necessary to maintain a medical follow-up to be adapted to the clinical situation of each woman and in particular, her cardiovascular and gynecological risk factors.

Effects of estrogen therapy and aerobic training on sympathetic activity and hemodynamics in healthy postmenopausal women: a double-blind randomized trial

OBJECTIVE

The aim of this study was to evaluate the isolated and associated effects of aerobic training and estrogen therapy on sympathetic nerve activity and hemodynamics in healthy postmenopausal women.

METHODS

Forty-five postmenopausal women (mean [SD] age, 51 [3] y) were randomly divided into four groups: sedentary-placebo (SED-PLA; n = 11), sedentary-estrogen therapy (SED-ET; n = 14), aerobic training-placebo (AT-PLA; n = 12), and aerobic training-estrogen therapy (AT-ET; n = 8). The ET groups received oral estradiol valerate (1 mg/d), whereas the PLA groups received placebo. The AT groups performed aerobic exercise three times a week on a cycle ergometer for 50 minutes, whereas the SED groups remained sedentary. All participants were evaluated before and after 6 months. Muscle sympathetic nerve activity (MSNA; microneurography), forearm blood flow (plethysmography), blood pressure (oscillometry), and heart rate (HR) were measured at rest for 10 minutes. Data were analyzed by three-way analysis of variance.

RESULTS

Estrogen administration itself did not change any of the studied parameters. AT improved forearm blood flow (AT-PLA, 2.02 [0.85] vs 2.92 [1.65] mL min(-1) 100 mL(-1), P = 0.03; AT-ET, 1.68 [1.11] vs 2.27 [0.76] mL min(-1) 100 mL(-1), P = 0.03), reduced MSNA in the AT-PLA group (39 [6] vs 34 [5] bursts/min(-1), P = 0.01), and decreased HR in the AT-ET group (65 [8] vs 62 [7] beats/min, P = 0.01).

CONCLUSIONS

AT reduces sympathetic nerve activity and improves muscle blood flow in healthy hysterectomized postmenopausal women. Moreover, AT decreases HR when combined with ET. However, ET abolishes the reducing effect of AT on MSNA.

Low-dose estrogen is as effective as high-dose treatment in rats with postmenopausal hypertension

: This study was conducted to test the hypothesis that 17β-estradiol therapy improves redox balance by decreasing reactive oxygen species production and increasing nitric oxide (NO) bioavailability, favoring Akt pathway activation and resulting in a better autonomic vascular control. Ovariectomized female Wistar rats were divided into 4 groups: (1) vehicle (VL) and animals treated with a pellet of 17β-estradiol for 21 days; (2) low dose (LE; 0.05 mg); (3) medium dose (ME; 0.2 mg); and (4) high dose (HE; 0.5 mg). Arterial pressure and its sympathetic nervous system modulation were evaluated by spectral analysis. Nitric oxide synthase and NADPH oxidase (Nox) activities, H2O2 concentration, redox status (GSH/GSSG), protein expression of Trx-1 and p-Akt/Akt were evaluated in the aorta, whereas NO metabolites were measured in the serum. Estrogen-treated groups showed a significant decrease in arterial pressure and sympathetic vascular drive. Redox status was significantly improved and NADPH oxidase and H2O2 were decreased in all estrogen-treated groups. Estrogen also induced an enhancement in NO metabolites, nitric oxide synthase activity, and Akt phosphorylation. This study demonstrated that estrogen treatment to ovariectomized rats induced cardioprotection, which was evidenced by reduced blood pressure variability and vascular sympathetic drive. These effects were associated with an improved redox balance and Akt activation, resulting in an enhanced NO bioavailability.

Efficacy of a low dose of estrogen on antioxidant defenses and heart rate variability

This study tested whether a low dose (40% less than the pharmacological dose of 17-β estradiol) would be as effective as the pharmacological dose to improve cardiovascular parameters and decrease cardiac oxidative stress. Female Wistar rats (n = 9/group) were divided in three groups: (1) ovariectomized (Ovx), (2) ovariectomized animals treated for 21 days with low dose (LE; 0.2 mg), and (3) high dose (HE; 0.5 mg) 17-β estradiol subcutaneously. Hemodynamic assessment and spectral analysis for evaluation of autonomic nervous system regulation were performed. Myocardial superoxide dismutase (SOD) and catalase (CAT) activities, redox ratio (GSH/GSSG), total radical-trapping antioxidant potential (TRAP), hydrogen peroxide, and superoxide anion concentrations were measured. HE and LE groups exhibited an improvement in hemodynamic function and heart rate variability. These changes were associated with an increase in the TRAP, GSH/GSSG, SOD, and CAT. A decrease in hydrogen peroxide and superoxide anion was also observed in the treated estrogen groups as compared to the Ovx group. Our results indicate that a low dose of estrogen is just as effective as a high dose into promoting cardiovascular function and reducing oxidative stress, thereby supporting the approach of using low dose of estrogen in clinical settings to minimize the risks associated with estrogen therapy.

Correlation of endogenous hormonal levels, fibroglandular tissue volume and percent density measured using 3D MRI during one menstrual cycle

BACKGROUND

We measured breast density (BD) on MRI and correlated with endogenous hormonal levels.

PATIENTS AND METHODS

Twenty-four premenopausal women received four weekly breast MRI. A blood sample was collected on the same day of MRI. BD was measured using a computer-based algorithm. The generalized estimation equation method was applied to model mean fibroglandular tissue volume (FV) and mean percent density (PD) from predictor variables including estradiol, progesterone, and week during a cycle.

RESULTS

In week 3, a borderline significant correlation between estradiol and PD (r = 0.43, P = 0.04), estradiol and FV (r = 0.40, P = 0.05) and between progesterone and FV (r = 0.42, P = 0.04) was noted. The FV and PD measured in weeks 4 and 1 were higher than in weeks 2 and 3, adjusted for variation in endogenous estradiol and progesterone, indicating that the hormone change could not account for the changes in density. No lag effect of endogenous hormone on the change of FV or PD was noted (all P-values > 0.05).

CONCLUSIONS

Our results showed that BD is not strongly associated with the endogenous hormone. Their association with breast cancer risk was likely coming from different mechanisms, and they should be considered as independent risk factors.

The management of menopause with complementary and alternative medicine using an experimental model: ovariectomized rats

AIM

The purpose of this research was to assess the effects of the flower essences She Oak and Bush Fuchsia on behavioral anxiety in ovariectomized (OVX) rats.

METHODS

For four weeks, OVX rats received the flower essences She Oak, Bush Fuchsia or a combination of the two. After flower therapy, the animals were subjected to an elevated plus maze (EPM) behavioral anxiety-test. Cortisol blood level was also evaluated.

RESULTS

OVX rats treated with the flower essence She Oak became less anxious and had more entries in the EPM open arms. On the other hand, OVX rats treated with the Bush Fuchsia essence spent more time in the EPM closed arms. This finding is similar to those obtained with controls. In addition, OVX rats that received She Oak and Bush Fuchsia in combination presented the same results as those receiving the Bush Fuchsia alone.

CONCLUSIONS

Our results suggest that the flower essence She Oak could have an anxiolytic effect in OVX rats, but that the combination therapy of the She Oak and Bush Fuchsia could avoid the effects of the She Oak.

Rationale for using raloxifene to prevent both osteoporosis and breast cancer in postmenopausal women

Both osteoporosis with fracture and breast cancer are important health issues for postmenopausal women. It is well known that estrogen and estrogen receptors (ERs) play an important role in the pathogenesis of both diseases. In past decades, hormone therapy (HT), mainly estrogen plus progestin (EPT), has been frequently used for the purpose of preventing and treating postmenopausal osteoporosis because of its efficacy, but it also contributes to a significant increase in breast cancer. Currently, there is a dilemma regarding the use of estrogen for postmenopausal women. Fortunately, an increasing understanding of the action of estrogen has led ultimately to the design of new drugs that work by virtue of their interaction with the ER; these drugs have come to be known as selective estrogen receptor modulators (SERMs), and are not only effective in preventing osteoporosis and managing those with osteoporosis, but also in decreasing the incidence of breast cancer. Among these SERMs, raloxifene may be the most attractive agent based on the evidence from five recent large trials (Multiple Outcomes of Raloxifene Evaluation [MORE], Continuing Outcomes Relevant to Evista [CORE], Raloxifene Use for the Heart [RUTH], Study of Tamoxifen and Raloxifene [STAR], and Evista Versus Alendronate [EVA]). The former three trials showed that raloxifene not only decreases the incidence of osteoporosis-associated fractures, but also has efficacy in breast cancer prevention. The head-to-head comparison with the anti-fracture agent alendronate (EVA trial) and the chemoprevention agent tamoxifen (STAR trial) further confirmed that raloxifene is a better choice. We concluded that since there is an absence of a therapeutic effect on relieving climacteric symptoms and there is the presence of a potential risk of thromboembolism in the use of raloxifene, this drug can be prescribed for clear indications, such as the management of osteoporosis, the prevention of fracture, and decreasing the incidence of invasive breast cancer, with careful monitoring for thromboembolism. It is reasonable to use raloxifene as an appropriate medicine that targets climacteric symptom-free postmenopausal women because of its overall favorable risk-benefit safety profile using the global index proposed by the Women's Health Initiation (WHI).