Comparative effects of conventional vs. novel hormone replacement therapy on blood pressure in postmenopausal women

Menopausal hyperinsulinism and hypertension - new approach

Aim: to test effects of estradiol (E2) 1 mg and drospirenone (DRSP) 2 mg in treatment of normal weight menopausal women with typical menopausal symptoms, hyperinsulinism, and grade I hypertension.Material and methods: The participants were 133 menopausal women, mean age 51.82 ± 3.25 years, body mass index (BMI) 24.9 ± 2.6 kg/m², waist/hip 0.80 ± 0.05, amenorrhoeic period 2.12 ± 2.10 years. All patients were treated with E2 1 mg and DRSP 2 mg during 12 months period. Blood samples were taken at 8 am before and during 12 months of therapy for: glycemia, lipids, hormonal analysis, follicle-stimulating hormone (FSH), luteinizing hormone (LH), E2, testosterone (T), prolactin (PRL), dehydroepiandrosterone sulfate (DHEAS), and sex hormone-binding globulin (SHBG). Oral glucose tolerance test (OGTT) was performed with 75 g glucose in order to assess insulin secretion. All had grade I hypertension 24 h blood pressure monitoring was performed before and after 12 months of therapy.Results: E2/DRSP significantly decreased total cholesterol, low-density lipoprotein (LDL), apolipoprotein B (ApoB), and increased high-density lipoprotein cholesterol (HDL) and apolipoprotein A (ApoA). Insulin area under the curve (AUC) significantly decreased (6586.1 ± 4194.2 vs. 5315.3 ± 2895.0, p < .05) and homeostatic model assessment (HOMA) (3.53 ± 2.18 vs. 3.0 ± 1.8, p < .05). FSH, LH decreased, E2 increased significantly. Of 24 h day blood pressure decreased significantly.Conclusions: E2/DRSP represents suitable therapy for hyperinsulinemic, grade I hypertensive menopausal women with typical symptoms and normal weight.

Endocrine Hypertension: A Practical Approach

Elevated blood pressure resulting from few endocrine disorders (endocrine hypertension) accounts for a high proportion of cases of secondary hypertension. Although some features may be suggestive, many cases of endocrine hypertension remain silent until worked up for the disease. A majority of cases result from primary aldosteronism. Other conditions that can cause endocrine hypertension are: congenital adrenal hyperplasia, Liddle syndrome, pheochromocytomas, Cushing's syndrome, acromegaly, thyroid diseases, primary hyperparathyroidism and iatrogenic hormone manipulation. Early identification and treatment of the cause of endocrine hypertension may help to reduce morbidity and mortality related to these disorders. This article gives a comprehensive and practical approach to the diagnosis and management of endocrine hypertension.

Sex hormones in the cardiovascular system

Gender-associated differences in the development of cardiovascular diseases have been described in humans and animals. These differences could explain the low incidence of cardiovascular disease in women in the reproductive period, such as stroke, hypertension, and atherosclerosis. The cardiovascular protection observed in females has been attributed to the beneficial effects of estrogen on endothelial function. Besides estrogen, sex hormones are able to modulate blood pressure by acting on important systems as cardiovascular, renal, and neural. They can have complementary or antagonistic actions. For example, testosterone can raise blood pressure by stimulating the renin-angiotensin-aldosterone system, whereas estrogen alone or combined with progesterone has been associated with decreased blood pressure. The effects of testosterone in the development of cardiovascular disease are contradictory. Although some researchers suggest a positive effect, others indicate negative actions of testosterone. Estrogens physiologically stimulate the release of endothelium-derived vasodilator factors and inhibit the renin-angiotensin system. Although the cardioprotective effects of estrogen are widely appreciated, little is known about the effects of progesterone, which is commonly used in hormone replacement therapy. Progesterone has both vasodilatory and vasoconstrictive effects in the vasculature, depending on the location of the vessel and the level of exposure. Nevertheless, the mechanisms through which sex hormones modulate blood pressure have not been fully elucidated. Therefore, the characterization of those could lead to a better understanding of hypertension in women and men and perhaps to improved forms of therapy.

Modification of blood pressure in postmenopausal women: role of hormone replacement therapy

The rate of hypertension increases after menopause. Whether estrogen and progesterone deficiency associated with menopause play a role in determining a worst blood pressure (BP) control is still controversial. Also, studies dealing with the administration of estrogens or hormone therapy (HT) have reported conflicting evidence. In general it seems that, despite some negative data on subgroups of later postmenopausal women obtained with oral estrogens, in particular conjugated equine estrogens (CEE), most of the data indicate neutral or beneficial effects of estrogen or HT administration on BP control of both normotensive and hypertensive women. Data obtained with ambulatory BP monitoring and with transdermal estrogens are more convincing and concordant in defining positive effect on BP control of both normotensive and hypertensive postmenopausal women. Overall progestin adjunct does not hamper the effect of estrogens. Among progestins, drospirenone, a spironolactone-derived molecule, appears to be the molecule with the best antihypertensive properties.

Postmenopausal hypertension and sodium sensitivity

It has been well established that women generally have lower incidence rates of hypertension than men at similar ages and these differences may vary with age. It also has been observed in many studies that after menopause, blood pressure (BP) increases in women to levels even higher than in men. The lack of estrogens may not be suggested as the only component involved in the development of postmenopausal hypertension. Thus, in this mini-review, the possible mechanisms by which sex hormones may influence the BP are discussed. This review also examines the renal regulatory mechanisms for gender differences in BP and explores the effects of salt intake on BP (salt-sensitivity) in pre and post-menopausal women.

Estrogen has been shown to stimulate nitric oxide (NO) production, thus female sex hormones have a beneficial effect on BP control. Evidences that angiotensin type 2 receptor (AT₂R) is up-regulated by estrogen support the favorable effects on BPs in women than men. The kidney plays an integral role in the regulation of arterial pressure through the mechanism of pressure-natriuresis, which has been shown to be modulated by the RAS. The prevalence of salt-sensitivity increases with age and low-salt diets has shown to help reduce systolic BP (SBP) and diastolic BP. While oral hormone replacement therapy has yielded only a neutral or minimal effect on the elevation of SBP, both the transdermal route replacement and a novel progestin with anti-aldosterone activity (drospirenone) has also shown to reduce SBP.

Blood pressure and mesenteric vascular reactivity in spontaneously hypertensive rats 7 months after gonadectomy

OBJECTIVE

Sexual dimorphism in the degree of high blood pressure (BP) has been observed in both animal and human hypertension. However, the mechanisms are still poorly understood. We tested the hypothesis that long-term loss of sex steroids promotes changes in mesenteric vascular reactivity that impact the maintenance of hypertension in the spontaneously hypertensive rats (SHR).

METHODS

Male SHR were sham operated (M-SHAM) or castrated (M-CX), and female SHR were sham-operated (F-SHAM) or ovariectomized (F-OVX) at 3 weeks of age. Seven months later, BP was measured in anesthetized rats, and vascular responsiveness was evaluated in the isolated perfused mesentery.

RESULTS

Mean arterial BP (mm Hg) was significantly greater in M-SHAM (186 ± 6) compared with F-SHAM (159 ± 5). Gonadectomy reduced BP in male SHR (M-CX: 160 ± 4) but had no significant effect in female SHR (F-OVX: 153 ± 7). Norepinephrine-induced constriction was similar in all groups. Gonadectomy attenuated serotonin-induced vasoconstriction in the mesentery. Acetylcholine (ACh)- and isoproterenol (ISO)-induced vasodilation was greater in female than male SHR. Ovariectomy of female SHR blunted ACh and ISO dilatory responses. ISO dose-response curves were shifted to the left in castrated male SHR.

CONCLUSIONS

Gonadectomy exerts long-term effects on mesenteric vascular reactivity and hypertension in the SHR.

Low-dose estrogen and drospirenone combination: effects on glycoinsulinemic metabolism and other cardiovascular risk factors in healthy postmenopausal women

OBJECTIVE

To evaluate the effects of a daily E2 (1 mg) plus drospirenone oral formulation (2 mg) on glycoinsulinemic metabolism, lipid profile, and endothelial function in symptomatic healthy menopausal women.

DESIGN

Randomized, double-blind study.

SETTING

Operative Division of Endocrinological Gynecology, Catholic University of the Sacred Heart, Rome, Italy.

PATIENT(S)

Forty postmenopausal women.

INTERVENTION(S)

Patients were randomly submitted to receive treatment with an oral dose of E2 (1 mg) plus drospirenone (2 mg) (group A) or placebo (group B).

MAIN OUTCOME MEASURE(S)

Hormonal and lipid assessment; evaluation of glucose and insulin metabolism by the clamp test and the oral glucose tolerance test; evaluation of endothelial function by the vascular reactivity test.

RESULT(S)

Total cholesterol levels, low-density lipoprotein cholesterol levels, and nonesterified fatty acids levels significantly decreased both after 3 and 6 months. No changes in high-density lipoprotein, triglycerides, apolipoprotein A1, apolipoprotein B, and lipoprotein (a) were found. Treatment resulted in few changes in glycoinsulinemic metabolism. We observed a significant reduction of the area under curve of insulin after 6 months of therapy. Endothelial function was significantly influenced by treatment, and an improvement in both flow-mediated dilatation and nitrate-mediated dilatation values after 6 months was observed.

CONCLUSION(S)

Low-dose E2/drospirenone treatment did not reveal any negative effect on carbohydrate metabolism, acting in a neutral way on insulin sensitivity. The treatment induced favorable changes in lipid profile and showed a significant improvement of vascular reactivity.