Effect of estradiol valerate alone or in association with cyproterone acetate upon vascular function of postmenopausal women at increased risk for cardiovascular disease

Effect of hormone replacement therapy with the anti-mineralocorticoid progestin Drospirenone compared to tibolone on endothelial function and central haemodynamics in post-menopausal women

Drospirenone (DRSP) is an antialdosterone agent with progestogenic and antiandrogenic effects. This compound, has been recently used in combination with 17β-estradiol (E2) as hormonal therapy in postmenopausal women and has been shown to exert a significant antihypertensive effect in hypertensive post-menopausal women. Aim of the present study was to compare the effect of DRSP/E2 with those of Tibolone (T) on endothelial function, arterial stiffness, and lipid profile of early postmenopausal women naïve on post-menopausal hormonal therapy. Twenty-four women met the inclusion criteria and entered the study. Women were randomized to receive either DRSP/E2 or T for 6months. Blood pressure and heart rate were similar in both groups at baseline and at the end of the study. Compared to baseline, endothelial function assessed by Reactive Hyperemia (RH) significantly improved in women receiving E2/DRSP, whereas no significant differences between baseline and follow up were detected in women receiving Tibolone. Women receiving E2/DRSP showed a significant decrease in pulse wave velocity and Augmentation Index compared to baseline while no changes were observed in women receiving Tibolone. The capacity of sera to trigger endothelial cells apoptosis in vitro measured by cell death assay was significantly reduced by E/DRSP but not by T (HFA-E 70±5,6% vs HFD-E 41±4,5%, p<0,001). In conclusion, the present study shows that the association of Estradiol and Drospirenone as hormonal replacement therapy significantly improves vascular parameters and the composition of sera relevant for vascular protection in early post-menopausal normotensive women. These effects are not shared by Tibolone.

Experimental benefits of sex hormones on vascular function and the outcome of hormone therapy in cardiovascular disease

Cardiovascular disease (CVD) is more common in men and postmenopausal women than premenopausal women, suggesting vascular benefits of female sex hormones. Experimental data have shown beneficial vascular effects of estrogen including stimulation of endothelium-dependent nitric oxide, prostacyclin and hyperpolarizing factor-mediated vascular relaxation. However, the experimental evidence did not translate into vascular benefits of hormone replacement therapy (HRT) in postmenopausal women, and HERS, HERS-II and WHI clinical trials demonstrated adverse cardiovascular events with HRT. The lack of vascular benefits of HRT could be related to the hormone used, the vascular estrogen receptor (ER), and the subject’s age and preexisting cardiovascular condition. Natural and phytoestrogens in small doses may be more beneficial than synthetic estrogen. Specific estrogen receptor modulators (SERMs) could maximize the vascular benefits, with little side effects on breast cancer. Transdermal estrogens avoid the first-pass liver metabolism associated with the oral route. Postmenopausal decrease and genetic polymorphism in vascular ER and post-receptor signaling mechanisms could also modify the effects of HRT. Variants of cytosolic/nuclear ER mediate transcriptional genomic effects that stimulate endothelial cell growth, but inhibit vascular smooth muscle (VSM) proliferation. Also, plasma membrane ERs trigger not only non-genomic stimulation of endothelium-dependent vascular relaxation, but also inhibition of [Ca²⁺]i, protein kinase C and Rho kinase-dependent VSM contraction. HRT could also be more effective in the perimenopausal period than in older postmenopausal women, and may prevent the development, while worsening preexisting CVD. Lastly, progesterone may modify the vascular effects of estrogen, and modulators of estrogen/testosterone ratio could provide alternative HRT combinations. Thus, the type, dose, route of administration and the timing/duration of HRT should be customized depending on the subject’s age and preexisting cardiovascular condition, and thereby make it possible to translate the beneficial vascular effects of sex hormones to the outcome of HRT in postmenopausal CVD.

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.

Angiotensin II receptor antagonism with telmisartan increases number of endothelial progenitor cells in normotensive patients with coronary artery disease: a randomized, double-blind, placebo-controlled study

INTRODUCTION

Circulating endothelial progenitor cells (EPCs) provide an endogenous repair mechanism of the dysfunctional endothelium and therefore can play a crucial role in the pathophysiology of coronary artery disease (CAD). Angiotensin II receptor antagonism has been shown to be able to increase EPCs in hypertension but its effect in patients with CAD is unknown. Aim of this study was to evaluate whether telmisartan, an angiotensin II receptor antagonist, can modify the number of subpopulations of EPCs and may in turn affect the endothelial function of normotensive patients with CAD.

METHODS

In a prospective double-blind parallel group study, 40 normotensive patients with CAD were randomly treated with telmisartan (80 mg) or placebo for 4 weeks at time of coronary angiography. Measurements of EPCs and assessment of flow-mediated dilatation (FMD) of the brachial artery was performed before and after therapy.

RESULTS

Absolute number of EPCs was similar at baseline in the telmisartan and placebo groups. After 4 weeks treatment, CD34+/KDR+/CD45- cells increased significantly in the telmisartan group (from 0.010+/-0.003 to 0.014+/-0.004%, P=0.0001) but not in the placebo group (from 0.009+/-0.004 to 0.009+/-0.005%, NS). Similarly, CD133+/KDR+/CD45- cells raised significantly with telmisartan (from 0.003+/-0.002 to 0.006+/-0.002%, P=0.0001) but not with placebo (from 0.004+/-0.003 to 0.003+/-0.002%, NS). Also, CD14+/CD45+ cells increased significantly with telmisartan (from 0.005+/-0.002 to 0.008+/-0.002%, P=0.0001) and were unchanged with placebo (0.006+/-0.002 vs. 0.005+/-0.003%, NS). FMD improved significantly in patients who received telmisartan (10.4+/-3.9%, P=0.0015 vs. baseline) but did not change in the placebo group (5.9+/-2.8%; P=0.32 vs. baseline; telmisartan vs. placebo, P=0.002). A significant positive correlation was found in the telmisartan group between the improvement in FMD and the increase in CD34+/KDR+/CD45- cells and CD133+/KDR+/CD45- cells (r=0.55, P<0.01, and r=0.49, P<0.05, respectively).

CONCLUSION

Angiotensin II receptor antagonism with telmisartan increases the number of regenerative EPCs and improves endothelial function in normotensive patients with CAD. These novel effects are interrelated and can explain, at least in part, why telmisartan has beneficial cardiovascular effects independent of its blood pressure lowering action.

Influence of vitamin E supplementation on endothelial complications in type 2 diabetes mellitus patients who underwent coronary artery bypass graft

BACKGROUND

Diabetes mellitus (DM) is associated with increased risk for complications following coronary artery bypass graft (CABG) surgery, in which tissue damage involves leukocyte-endothelial interactions mediated by endothelin-1 (ET-1) and adhesion molecules (AMs).

AIM

This study compared lipids and their peroxidation product, malondialdehyde (MDA), high-sensitivity C-reactive protein (hsCRP), ET-1, platelet-selectin (P-selectin), intercellular AM-1 (ICAM-1), and vascular cell AM-1 (VCAM-1) between healthy controls and type 2 DM subjects who did not receive CABG surgery as well as those who did. Vitamin E as an adjunctive therapy in subjects who underwent CABG was evaluated.

METHODS

ELISA was used to measure hsCRP, ET-1, and AMs. For all subjects, glycosylated hemoglobin (HbA(1c)) and lipid profile were estimated.

RESULTS

Percentage of HbA(1c), lipids, MDA, hsCRP, ET-1, P-selectin, ICAM-1, and VCAM-1 levels were significantly higher in the diabetic groups than in healthy controls. Vitamin E supplementation for 3 successive months significantly lowered MDA, hsCRP, ET-1, ICAM-1, and VCAM-1 levels by 64%, 47%, 12%, 74%, and 25%, respectively. However, high-density lipoprotein cholesterol (HDL-C) and vitamin E serum levels were increased by 65% and 90.55%, respectively (P<or=.05). Vitamin E cosupplementations correlated restored ET-1, P-selectin, and ICAM-1 levels, which have been functionally damaged by decreased HDL-C, hypercholesterolemia, and hypertriacylglycerolemia, respectively.

CONCLUSION

This study indicates that increased levels of the proinflammatory markers and AMs occur in type 2 DM. Vitamin E administration appears beneficial in lowering proinflammatory markers and their downstream effectors that played an important role in diabetic complications following CABG.

Time since menopause influences the acute and chronic effect of estrogens on endothelial function

OBJECTIVE

We evaluated whether time since menopause influences the acute and chronic effect of Estradiol (E) on vascular endothelial function.

METHODS AND RESULTS

We studied flow-mediated dilatation (FMD) in 134 postmenopausal women (PMW) before and after acute and chronic E administration. At baseline FMD was inversely associated to time from menopause (r=-0.67, P<0.001) and age (r=-0.43, P<0.05), in exogenous estrogen naïve but not in previous users. Acute and chronic E improved endothelial function in all women. E administration improved FMD more in women within 5 years since menopause than in those with more than 5 years since menopause (76% and 74% versus 45% and 48%, acute and chronic E, respectively; P<0.05). Among women with more than 5 years since menopause acute and chronic E increased FMD more in previous E users than in nonusers (59% and 63% versus 31% and 38%, acute and chronic E, respectively; P<0.01). Multivariate analysis showed that time from menopause was a predictor of impaired FMD and of its improvement after acute and chronic E.

CONCLUSIONS

Time from menopause influences FMD in PMW. The acute and chronic effect of E on FMD is time dependent and is reduced by a longer time since menopause.

Evaluation of C-reactive protein, endothelin-1, adhesion molecule(s), and lipids as inflammatory markers in type 2 diabetes mellitus patients

This study compared lipids, the product of lipid peroxidation malondialdehyde (MDA), the acute phase reactant high-sensitive C-reactive protein (hsCRP), endothelin-1 (ET-1), P-selectin, intercellular adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-1 (VCAM-1) between healthy controls, subjects with ischemic heart disease (IHD) and type 2 diabetes mellitus (DM) subjects who did not perform coronary artery bypass graft (CABG) surgery as well as type 2 DM subjects who performed CABG. HbA_1c, lipids, MDA, hsCRP, ET-1, P-selectin, ICAM-1, and VCAM-1 levels were significantly higher in the diabetic groups than in either healthy controls or IHD subjects. In the diabetic groups, there was a negative association among hsCRP and HDL-C. ET-1, ICAM-1 levels, and TAG were positively correlated, as do the association between P-selectin, VCAM-1, and HbA_1c%. Also a positive relation was found among hsCRP levels and ICAM-1, as well as MDA and ET-1. P-selectin and ICAM-1 were significantly positively correlated. This study indicates that increased level of oxidative stress marker, proinflammatory markers, and their downstream effectors adhesion molecules occur in type 2 DM.

Hormones and cardiovascular health in women

Cardiovascular diseases (CVDs) may have their origin before birth: the combination of being small at birth and having an overly rich post-natal diet increases the likelihood of obesity and of acquiring a specific metabolic syndrome in adulthood that carries an increased risk of CVD. The incidence of CVD and mortality is very low in women of reproductive age but rises to a significant level in older women. In this article, we discuss CVD in relation to hormonal contraception, pregnancy and polycystic ovarian syndrome (PCOS) in younger women and menopause in older women. Women with PCOS have a higher risk of diabetes and hypertension, but studies to date have not shown an effect on CVD events. Use of combined hormonal contraception has only small effects on CVD because of the low baseline incidence of myocardial infarction (MI), stroke and venous thromboembolism (VTE) among young women. Women with existing risk factors or existing CVD, however, should consider alternative contraception. In pregnancy, CVD is rare, although, in the West, it now accounts for a significant proportion of maternal mortality as the frequency of obstetrical causes of mortality has substantially declined. The frequency of VTE is 15 per 10,000 during pregnancy and the post-partum period. In older women, menopause causes a slightly higher risk of MI after allowing for age, although there is substantial heterogeneity in the results of studies on menopause and age at menopause and MI. A larger effect might have been expected, because estrogen reduces the risk of developing atherosclerosis in premenopausal women, whereas in post-menopausal women who may have established atherosclerotic disease, estrogen increases the risk of myocardial disease through the effects on plaque stability and clot formation. Recent trial results indicate that hormone treatment in menopause does not favourably affect the risk of MI, stroke or other vascular disease. Thus, prevention of CVD should rely on diet and fitness, low-dose aspirin and treatment of hypertension, hyperglycaemia and hyperlipidaemia.

Metformin improves endothelial function in patients with metabolic syndrome

BACKGROUND

Metabolic Syndrome (MS) is associated with impaired endothelial function and increased cardiovascular risk. Insulin resistance is a key feature of MS and plays an important role in the pathogenesis of endothelial dysfunction. Aim of the present study was to evaluate the effect of metformin on endothelial function and insulin resistance, assessed by the homeostasis model (HOMA-IR, homeostasis model assessment-insulin resistance), in patients with MS.

METHODS

Sixty-five subjects (37 men and 28 women, mean age 54 +/- 6 years) with MS were allocated to receive metformin 500 mg twice daily (n = 32) or placebo (n = 33) for 3 months. Before and after treatment we assessed endothelial function, using flow-mediated dilatation of the brachial artery, and HOMA-IR.

RESULTS

Patients who received metformin demonstrated statistically significant improvement in endothelium-dependent vasodilation compared with those treated with placebo (from 7.4 +/- 2.1% to 12.4 +/- 1.9% vs. 7.3 +/- 2.5% to 6.9 +/- 2.7%, P = 0.0016, metformin vs. placebo respectively), without significant effect on endothelium-independent response to sublingual glyceryl trinitrate (P =0.32). Metformin improved insulin resistance compared with placebo group (HOMA-IR from 3.39 to 2.5 vs. 3.42 to 3.37; 26% reduction in HOMA-IR, P = 0.01). An association between the improvement in insulin resistance and the improvement in endothelial function (r = -0.58, P = 0.0016) was found.

CONCLUSION

Metformin improves both endothelial function and insulin resistance in patients with MS. These findings support the central role of insulin resistance in the development of endothelial dysfunction and the role of metformin for the treatment of patients with MS.

Different effect of hormone replacement therapy, DHEAS and tibolone on endothelial function in postmenopausal women with increased cardiovascular risk

Menopause is associated with an increased cardiovascular risk and with a decrease in endothelial function. Hormone replacement therapy (HRT) improves endothelial function in post-menopausal women (PMW) without established atherosclerosis. New alternative treatments, among which tibolone (T) and DHEAS have been suggested to reduce postmenopausal cardiovascular risk. Although, in vitro animal studies have suggested that T and DHEAS improve endothelial function, their effect in humans has never been tested. The aim of the present study was to compare the effects of HRT (continuous combined 0.625 mg conjugated equine estrogen plus 2.5 mg/d medoxyprogesterone) DHEAS and T on endothelium-dependent flow-mediated vasodilatation (FMD), plasma nitrite, nitrate and endothelin-1 levels in 16 PMW with increased cardiovascular risk in a double-blinded, double-crossover study. Women were randomized and treated for 4 weeks with HRT, T or DHEAS. Brachial artery diameter, FMD, endothelin-1 and plasma nitrite and nitrate levels were measured at baseline and after each treatment phase. Brachial artery diameters remained unchanged after each treatment phase. HRT significantly improved FMD compared to both baseline and to T and DHEAS therapies while no effect of T or DHEAS on FMD was noted. In conclusion, HRT, but neither T nor DHEAS, improves endothelial function and reduces plasma levels of endothelin-1 in PMW at risk of CAD.

Chronic Treatment with Tadalafil Improves Endothelial Function in Men with Increased Cardiovascular Risk

OBJECTIVE

Erectile dysfunction (ED) is often associated with a cluster of risk factors for coronary artery disease and reduced endothelial function. Acute and chronic administration of oral sildenafil, a phosphodiesterase type 5 (PDE5) inhibitor, improves endothelial function in patients with ED. Tadalafil (TAD) is a new PDE5 inhibitor with a long half life that allows alternate day administration. Aim of the study was to evaluate whether chronic therapy (4 weeks) with TAD improves endothelial function in patients with increased cardiovascular risk and whether this effect is sustained after discontinuation of therapy.

METHODS

We randomized 32 patients with increased cardiovascular risk to receive either TAD 20 mg on alternate days or matching placebo (PLB) for 4 weeks. Patients underwent evaluation of brachial artery flow-mediated dilation (FMD), nitrite/nitrate and endothelin-1 plasma levels at baseline, at the end of treatment period and after two-weeks follow-up.

RESULTS

At 4 weeks, FMD was significantly improved by TAD (from 4.2+/-3.2 to 9.3+/-3.7%, p<0.01 vs. baseline), but was not modified by PLB (from 4.1+/-2.8 to 4.0+/-3.4%, p=NS). At 6 weeks the benefit in FMD was sustained in patients that received TAD (9.1+/-3.9% vs. 4.2+/-3.2%, p=0.01 vs. baseline; 9.1+/-3.9% vs. 9.3+/-3.7%, vs. 4 weeks, p=NS) while no changes in FMD were observed in patients randomized to PLB. Also, compared to baseline, a net increase in nitrite/nitrate levels (38.2+/-12.3 vs. 52.6+/-11.7 and 51.1+/-3.1, p<0.05) and a decrease in endothelin-1 levels (3.3+/-0.9 vs. 2.9.+/-0.7 and 2.9+/-0.9, p<0.05) was found both at four and six-weeks after TAD; these changes were inversely correlated as shown by regression analysis (adjusted R2=0.81, p<0.0001).

CONCLUSIONS

Chronic therapy with TAD improves endothelial function in patients with increased cardiovascular risk regardless their degree of ED. The benefit of this therapy is sustained for at least two weeks after the discontinuation of therapy. Larger studies are needed in order to assess the possible clinical implications of chronic therapy with TAD.

Differential effects of progestins on hemostasis

Recently large, prospective, randomized studies on hormone replacement therapy (HRT) have indicated that the progestin use might interfere with hemostasis and thus increase venous thrombotic events. Therefore, available publications were evaluated to determine whether progestins interfere with hemostasis, either when given alone via oral or parenteral routes or in combination with ethinylestradiol as synthetic estrogen or natural estrogens. There are indications that such interference is dependent upon the type and dose of the progestin, the route of application, the length of treatment and the type and dose of the estrogen with which it is combined. For natural progesterone, no negative effects on the hemostatic system were seen with either oral or parenteral application, in cyclic or continuous regimens, for the doses investigated. Similarly, no unwanted effects were seen with progestin only pills (POP), independent of the type and dose of progestin, or parenteral progestins. With the high-dose progestins used in gynaecological oncology, the increased activation of the hemostatic system resulting from the disease itself has to be taken into account when looking at any increased incidence of thromboembolic events in these patients. For estrogen/progestin combinations, the risk of venous thromboembolism is attributed to the estrogen used. Recent studies showed an increased rate of thromboembolic events in association with desogestrel-and gestodene-containing oral contraceptives, compared with those containing levonorgestrel. With HRT, a decrease in antithrombin factors could explain the increased rate of venous thrombotic events. In conclusion, progestins seems to have different effects on the hemostatic system due to their different pattern of biological activities. This was also shown in the arterial vascular system, where some progestins may reduce the endothelium-dependent vasodilating action of estrogens and stimulate intima proliferation and upregulate thrombin receptor expression while other progestins did not.

Metabolic and vascular effect of progestins in post-menopausal women. Implications for cardioprotection

Estrogen therapy causes changes in a variety of cardiovascular risk factors, including insulin resistance, lipoprotein profile, haemostasis, coronary atherosclerosis and vascular reactive, that suggest a potential cardioprotective effect in postmenopausal women. With respect to the role of adjunctive progestins, currently available data suggest that the cardiovascular effects may differ depending on the type, dosage and route of administration of the progestin. Androgenic progestins antagonise the favourable cardiovascular effect of estrogens, whilst non-androgenic progestins do not impair, or may even enhance, the beneficial effect of estrogens. Therefore, less androgenic progestins would appear to be the agent of choice for combined hormone therapy in postmenopausal women with cardiovascular risk factors.

Comparative vascular effects of hormone replacement therapy and raloxifene in women at increased cardiovascular risk

Hormone replacement therapy (HRT) improves endothelial function in postmenopausal women while the effects of raloxifene, a selective estrogen receptor modulator, are still under debate. The aim of this study was to evaluate endothelium-dependent flow-mediated vasodilatation in the brachial artery and plasma levels of nitrite, nitrate and endothelin-1 in 20 postmenopausal women with increased cardiovascular risk treated with either HRT or raloxifene for 4 weeks in a randomized double-blind single cross-over study. Patients had an endothelium-dependent flow-mediated dilatation of 4% prior to initiation of the study. Treatment with HRT resulted in a 67% increase in dilatation compared with baseline (from a 7.4% increase to a 12.4% increase, p < 0.01). Raloxifene treatment resulted in no change in vasodilatation from baseline. Endothelium-dependent dilatation was significantly improved by HRT compared with raloxifene treatment (12.4+/-0.6% vs. 6.1+/-2.0%; p < 0.01). Compared with baseline values, nitrate plus nitrite levels increased significantly (p < 0.05) with HRT but not with raloxifene. Similarly, endothelin-1 decreased from baseline with both treatments, but only the HRT-induced decrease was statistically significant (p < 0.05). In conclusion, HRT improved endothelial function and reduced plasma levels of endothelin-1 in postmenopausal women at risk of coronary artery disease. These beneficial effects were not shared by raloxifene.

Effect of genistein on endothelial function in postmenopausal women: a randomized, double-blind, controlled study

PURPOSE

Genistein, a phytoestrogen found in soybeans, corrects endothelial dysfunction induced by oophorectomy in animals. Using a double-blind, controlled, randomized design, we evaluated its effects on endothelial function in women.

METHODS

We enrolled 79 healthy postmenopausal women (mean [+/- SD] age, 56 +/- 4 years) and randomly assigned them to receive continuous estrogen/progestin therapy (n = 26; 17beta-estradiol [1 mg/d] combined with norethisterone acetate [0.5 mg/d]), genistein (n = 27; 54 mg/d), or placebo (n = 26). Brachial artery flow-mediated, endothelium-dependent vasodilation and plasma levels of nitrites/nitrates (a marker of nitric oxide metabolism) and endothelin-1 were measured at baseline and after 1 year of therapy.

RESULTS

Treatment with genistein increased levels of nitrites/nitrates (mean increase, 21 micromol/L; 95% confidence interval [CI]: 15 to 26 micromol/L; P <0.001 vs. placebo); estrogen/progestin therapy caused similar changes (P <0.001 vs. placebo). Plasma endothelin-1 levels decreased following 12 months of genistein (mean decrease, 7 pg/mL; 95% CI: 3 to 10 pg/mL; P <0.001 vs. placebo) and after 12 months of estrogen/progestin (P <0.001 vs. placebo). When compared with placebo, brachial artery flow-mediated dilation was improved by genistein (mean increase, 5.5%; 95% CI: 3.9% to 7.0%; P <0.001) and by estrogen/progestin (P <0.001). There were no significant differences between estrogen and genistein for any of these parameters (all P >0.4).

CONCLUSION

One year of genistein therapy improves endothelium function in postmenopausal women to a similar extent as does an estrogen/progestin regimen.

Vascular reactivity in hypogonadal men is reduced by androgen substitution

The effect of testosterone (T) substitution therapy on blood vessel functions in relation to cardiovascular disease has not been fully elucidated. In 36 newly diagnosed nonsmoking hypogonadal men (37.5 +/- 12.7 yr) endothelium-dependent flow-mediated vasodilatation (FMD; decreased in atherosclerosis) of the brachial artery was assessed before treatment and after 3 months of T substitution therapy (250 mg testosterone enanthate im every 2 wk in 19 men, human chorionic gonadotropin sc twice per week in 17 men). Twenty nonsmoking controls matched for age, low-density lipoprotein cholesterol (LDL-C), body height, and baseline diameter of the artery were selected for repeated measurements from a larger eugonadal control group (n = 113). In hypogonadal men, basal FMD (17.9 +/- 4.5%) was significantly higher than in the large (11.9 +/- 6.4%) and matched control (11.8 +/- 7.1%, both P < 0.001) groups. Grouped multiple linear regression analysis revealed a significant negative association of T levels with FMD within the hypogonadal range, but no significant association was seen within the eugonadal range. During substitution therapy, T levels increased from 5.8 +/- 2.3 to 17.2 +/- 5.1 nmol/liter and FMD decreased significantly to 8.6 +/- 3.1% (P < 0.001, analysis for covariance for repeated measurements including matched controls). LDL-C and advanced age contributed significantly to decrease FMD (P = 0.01, P = 0.04, respectively). Because T substitution adversely affects this important predictor of atherosclerosis, other contributing factors (such as smoking, high blood glucose, and LDL-C) should be eliminated or strictly controlled during treatment of hypogonadal men.

Dydrogesterone does not reverse the effects of estradiol on endothelium-dependant vasodilation in postmenopausal women: a randomised clinical trial

OBJECTIVES

The purpose of this study was to evaluate endothelium-dependent flow-mediated dilation (FMD) in the brachial artery and the plasma levels of endothelin-1 in postmenopausal women at risk for coronary artery disease before and after treatment with both estradiol and estradiol plus dydrogesterone.

METHODS

Sixteen postmenopausal women (PMW) (mean age 58+/-9 years) with more than two risk factors for coronary artery disease, were randomized to receive either oral estradiol (2 mg) for 28 days or oral estradiol (2 mg) for 14 days and oral estradiol (2 mg) and dydrogesterone (10 mg) for 14 days, in a double-blind, placebo-controlled, single cross-over study. Patients were crossed-over the complementary treatment 7 days after completing the first treatment. The study of forearm blood flow and the measurement of plasma endothelin-1 levels was carried out before and after each treatment.

RESULTS

Estradiol significantly increased FMD as compared to baseline; the addition of dydrogesterone did not affect the effect of estradiol on FMD. Similarly reactive hyperemic flow increased after estradiol alone or in association with dydrogesterone compared to baseline. Plasma levels of endothelin-1 were significantly reduced by estradiol both when administered alone or in association with dydrogesterone.

CONCLUSIONS

Hormone replacement therapy with estradiol and dydrogesterone improves endothelial function and reduces plasma levels of endothelin-1 in PMW at risk for coronary artery disease.