Vascular effects of estrogen in type II diabetic postmenopausal women

Effect of Postmenopausal Hormone Therapy on Glucose Regulation in Women With Type 1 or Type 2 Diabetes: A Systematic Review and Meta-analysis

BACKGROUND

Blood glucose regulation in women with diabetes may change during and after menopause, which could be attributed, in part, to decreased estrogen levels.

PURPOSE

To determine the effect of postmenopausal hormone therapy (HT) on HbA1c, fasting glucose, postprandial glucose, and use of glucose-lowering drugs in women with type 1 and women with type 2 diabetes.

DATA SOURCES

We conducted a systematic search of MEDLINE, Embase, Scopus, the Cochrane Library, and the ClinicalTrials.gov registry to identify randomized controlled trials (RCTs).

STUDY SELECTION

We selected RCTs on the effect of HT containing estrogen therapy in postmenopausal women (≥12 months since final menstrual period) with type 1 or type 2 diabetes.

DATA EXTRACTION

Data were extracted for the following outcomes: HbA1c, fasting glucose, postprandial glucose, and use of glucose-lowering medication.

DATA SYNTHESIS

Nineteen RCTs were included (12 parallel-group trials and 7 crossover trials), with a total of 1,412 participants, of whom 4.0% had type 1 diabetes. HT reduced HbA1c (mean difference -0.56% [95% CI -0.80, -0.31], -6.08 mmol/mol [95% CI -8.80, -3.36]) and fasting glucose (mean difference -1.15 mmol/L [95% CI -1.78, -0.51]).

LIMITATIONS

Of included studies, 50% were at high risk of bias.

CONCLUSIONS

When postmenopausal HT is considered for menopausal symptoms in women with type 2 diabetes, HT is expected to have a neutral-to-beneficial impact on glucose regulation. Evidence for the effect of postmenopausal HT in women with type 1 diabetes was limited.

Visceral fat and attribute-based medicine in chronic kidney disease

Visceral adipose tissue plays a central role in obesity and metabolic syndrome and is an independent risk factor for both cardiovascular and metabolic disorders. Increased visceral adipose tissue promotes adipokine dysregulation and insulin resistance, leading to several health issues, including systemic inflammation, oxidative stress, and activation of the renin-angiotensin-aldosterone system. Moreover, an increase in adipose tissue directly and indirectly affects the kidneys by increasing renal sodium reabsorption, causing glomerular hyperfiltration and hypertrophy, which leads to increased proteinuria and kidney fibrosis/dysfunction. Although the interest in the adverse effects of obesity on renal diseases has grown exponentially in recent years, the relationship between obesity and renal prognosis remains controversial. This may be attributed to the long clinical course of obesity, numerous obesity-related metabolic complications, and patients' attributes. Multiple individual attributes influencing the pathophysiology of fat accumulation make it difficult to understand obesity. In such cases, it may be effective to elucidate the pathophysiology by conducting research tailored to individual attributes from the perspective of attribute-based medicine/personalized medicine. We consider the appropriate use of clinical indicators necessary, according to attributes such as chronic kidney disease stage, level of visceral adipose tissue accumulation, age, and sex. Selecting treatments and clinical indicators based on individual attributes will allow for advancements in the clinical management of patients with obesity and chronic kidney disease. In the clinical setting of obesity-related nephropathy, it is first necessary to accumulate attribute-based studies resulting from the accurate evaluation of visceral fat accumulation to establish evidence for promoting personalized medicine.

Gender Difference in the Risk of Adverse Outcomes After Diabetic Foot Disease: A Mini-Review

Diabetic foot disease (DFD) is a complication of diabetes mellitus, characterized by multiple pathogenetic factors, bearing a very high burden of disability as well as of direct and indirect costs for individuals or healthcare systems. A further characteristic of DFD is that it is associated with a marked risk of subsequent hospitalizations for incident cardiovascular events, chronic renal failure or of allcause mortality. Additionally, DFD is strongly linked to the male sex, being much more prevalent among men. However, even if DFD mainly affects males, several past reports suggest that females are disadvantaged as regards the risk of subsequent adverse outcomes. This review aims to clarify this point, attempting to provide an explanation for this apparent oddity: being DFD a typically male complication of diabetes but, seemingly, with a greater load of subsequent consequences for females.

Obesity and cardiovascular disease in women

As the prevalence of obesity continues to grow worldwide, the health and financial burden of obesity-related comorbidities grows too. Cardiovascular disease (CVD) is clearly associated with increased adiposity. Importantly, women are at higher risk of CVD when obese and insulin resistant, in particular at higher risk of developing heart failure with preserved ejection fraction and ischemic heart disease. Increased aldosterone and mineralocorticoid receptor activation, aberrant estrogenic signaling and elevated levels of androgens are among some of the proposed mechanisms explaining the heightened CVD risk. In addition to traditional cardiovascular risk factors, understanding nontraditional risk factors specific to women, like excess weight gain during pregnancy, preeclampsia, gestational diabetes, and menopause are central to designing personalized interventions aimed to curb the epidemic of CVD. In the present review, we examine the available evidence supporting a differential cardiovascular impact of increased adiposity in women compared with men and the proposed pathophysiological mechanisms behind these differences. We also discuss women-specific cardiovascular risk factors associated with obesity and insulin resistance.

Estrogen effects on arteries vary with stage of reproductive life and extent of subclinical atherosclerosis progression

The past several years have been marked by confusion and controversy concerning whether estrogens are cardioprotective. The issue is of utmost public health importance because coronary heart disease (CHD) remains the leading cause of death among postmenopausal women. Fortunately, a unifying hypothesis has emerged that reproductive stage is a major determinant of the effect of estrogens on atherosclerosis progression, complications, and plaque vulnerability.

PREMENOPAUSAL YEARS

Premenopausal atherosclerosis progression seems to be an important determinant of postmenopausal atherosclerosis and thus the risk for CHD. Clearly, plasma lipids/lipoproteins influence this progression; however, estradiol deficiency seems to be the major modulator. Both monkeys and women with premenopausal estrogen deficiency develop premature atherosclerosis, an effect that can be prevented in both species by estrogen-containing oral contraceptives.

PERIMENOPAUSAL/EARLY POSTMENOPAUSAL YEARS

During this stage, there are robust estrogen benefits. Monkeys given estrogens immediately after surgical menopause have a 70% inhibition in coronary atherosclerosis progression. Estrogen treatment prevented progression of atherosclerosis of women in the Estrogen in the Prevention of Atherosclerosis Trial. A meta-analysis of women younger than 60 years given hormone therapy had reduced total mortality (relative risk = 0.61, 95% CI: 0.39-0.95).

LATE POSTMENOPAUSAL YEARS

This stage is one in which there are no or possible deleterious estrogen effects. Monkeys lose CHD benefits of estrogens when treatment is delayed. The increase in CHD events associated with initiating hormone therapy 10 or more years after menopause seems to be related to up-regulation of the plaque inflammatory processes and plaque instability and may be down-regulated by statin pretreatment.

Gender difference in diabetes related excess risk of cardiovascular events: When does the 'risk window' open?

OBJECTIVE

Women with diabetes have a greater excess risk for cardiovascular diseases (CVD) than men. This study was aimed at clarifying whether this effect is lifelong or more evident in some life-periods.

METHODS

The effect of diabetes and gender on the risk of first ever hospitalization for acute myocardial infarction (AMI), ischemic stroke (IS), congestive heart failure (CHF), lower extremity amputations (LEA) or any of these major cardiovascular events (MACE) have been evaluated by a Cox-hazard model, over years 2008-2012 querying administrative databases of a cohort living in Tuscany, Italy.

RESULTS

Comparing subjects with diabetes to those without it the overall age-adjusted excess risk was higher in women than in men for AMI and MACE and higher in men for LEA, with no difference for IS or CHF. In women the excess risk for AMI and MACE started earlier (46yr) and lasted until age of more than 85yr, while 'risk-windows' opened later and had a shorter duration for CHF (56-65yr) and IS (66-75yr).

CONCLUSION

Diabetic women have a significant diabetes-associated excess of CVD risk, except for LEA, with a 'risk window' opening earlier and lasting longer for AMI and MACE, later and with a shorter duration for IS and CHF.

Gender difference in diabetes-associated risk of first-ever and recurrent ischemic stroke

OBJECTIVE

To evaluate the effect of diabetes by gender on the peak-risk of first-ever-ischemic stroke and its recurrence.

METHODS

Administrative datasets including all hospital discharges for ischemic stroke (N = 43,332) in the diabetic (N = 207,568) and non-diabetic (N = 2,808,554) population of the Tuscany region, Italy were used to calculate Hazard ratios (HR) after Cox-regression, of first-ever and recurrent ischemic strokes, between 2005 and 2011.

RESULTS

Overall, diabetes increased the HR of first-ever ischemic stroke by about 50% in both genders. However, this risk significantly declined with age and was higher in women aged 55-74 yr than in men of the same age (HR; 95% CI: 1.392; 1.228-1.579 in age-class 55-64 yr and 1.203; 1.110-1.304 in age class 65-74 yr; p < 0.001). Diabetes also increased the adjusted risk of three-year-stroke recurrence (N = 5,998) in women, independently of age, whereas this was the case in men < 70 yr.

CONCLUSIONS

Diabetes is associated with increased risk of ischemic stroke although it declines with age though at lower rate among women than men. Moreover, diabetic women have greater risk of recurrence than in men > 70 yrs old, supporting a high-risk "time-window" in postmenopausal-elderly diabetic women.

Daily blueberry consumption improves blood pressure and arterial stiffness in postmenopausal women with pre- and stage 1-hypertension: a randomized, double-blind, placebo-controlled clinical trial

BACKGROUND

Postmenopausal women have a high prevalence of hypertension and often develop arterial stiffness thereby increasing cardiovascular disease risk. Although antihypertensive drug therapies exist, increasing numbers of people prefer natural therapies. In vivo studies and a limited number of clinical studies have demonstrated the antihypertensive and vascular-protective effects of blueberries.

OBJECTIVE

To examine the effects of daily blueberry consumption for 8 weeks on blood pressure and arterial stiffness in postmenopausal women with pre- and stage 1-hypertension.

DESIGN

This was an 8-week, randomized, double-blind, placebo-controlled clinical trial.

PARTICIPANTS/SETTING

Forty-eight postmenopausal women with pre- and stage 1-hypertension recruited from the greater Tallahassee, FL, area participated.

INTERVENTION

Participants were randomly assigned to receive either 22 g freeze-dried blueberry powder or 22 g control powder.

MAIN OUTCOME MEASURES

Resting brachial systolic and diastolic blood pressures were evaluated and arterial stiffness was assessed using carotid-femoral pulse wave velocity and brachial-ankle pulse wave velocity. C-reactive protein, nitric oxide, and superoxide dismutase were measured at baseline, 4 weeks, and 8 weeks.

STATISTICAL ANALYSES PERFORMED

Statistical analysis was performed using a split plot model of repeated measures analysis of variance.

RESULTS

After 8 weeks, systolic blood pressure and diastolic blood pressure (131±17 mm Hg [P<0.05] and 75±9 mm Hg [P<0.01], respectively) and brachial-ankle pulse wave velocity (1,401±122 cm/second; P<0.01) were significantly lower than baseline levels (138±14 mm Hg, 80±7 mm Hg, and 1,498±179 cm/second, respectively), with significant (P<0.05) group×time interactions in the blueberry powder group, whereas there were no changes in the group receiving the control powder. Nitric oxide levels were greater (15.35±11.16 μmol/L; P<0.01) in the blueberry powder group at 8 weeks compared with baseline values (9.11±7.95 μmol/L), whereas there were no changes in the control group.

CONCLUSIONS

Daily blueberry consumption may reduce blood pressure and arterial stiffness, which may be due, in part, to increased nitric oxide production.

Coronary Heart Disease in Postmenopausal Women with Type II Diabetes Mellitus and the Impact of Estrogen Replacement Therapy: A Narrative Review

Coronary heart disease is the main cause of death in postmenopausal women (PMW); moreover its mortality exceeds those for breast cancer in women at all ages. Type II diabetes mellitus is a major cardiovascular risk factor and there is some evidence that the risk conferred by diabetes is greater in women than in men. It was established that the deficiency of endogenous estrogens promotes the atherosclerosis process. However, the impact of estrogen replacement therapy (ERT) on cardiovascular prevention remains controversial. Some authors strongly recommend it, whereas others revealed a concerning trend toward harm. This review tries to underlines the different components of cardiovascular risk in diabetic PMW and to define the place of ERT.

Combination of caregiving stress and hormone replacement therapy is associated with prolonged platelet activation to acute stress among postmenopausal women

OBJECTIVE

To investigate the combined effects of caregiving and hormone replacement therapy (HRT) on platelet hyperactivity to acute psychological stress. Both HRT and the chronic stress of caregiving have been associated with increased cardiovascular risk, potentially through a mechanism of platelet hyperactivity.

METHODS

A total of 78 elderly postmenopausal women (51 caregivers (CG) and 27 noncaregivers (NC)) were assessed for platelet activation in response to a laboratory speech test. Half the sample was taking HRT. Blood was sampled at baseline, post speech, and after 14 minutes of recovery. Platelet activation was assessed through whole blood flow cytometry assays of % aggregates (Agg), and expression of % fibrinogen receptors (FbR) and % P-selectin (P-sel) on platelet surface.

RESULTS

Multivariate repeated-measures analysis of variance revealed that CG taking HRT exhibited significantly prolonged platelet activation in response to acute stress. There was an interaction between HRT and CG on recovery from stress for Agg (F (1,71) = 5.260, p = .025), P-Sel (F(1,71 = 6.426, p = .013), and FbR (F(1,71 = 6.653, p = .012), controlling for age, cardiovascular disease, and aspirin. Among HRT users, regression analysis revealed that CG had delayed recovery of Agg (beta = 0.354, t(34) = 2.154, p = .038) and P-sel (beta = 0.498, t(34)=3.126, p = .004) from stress relative to NC. No caregiving effects on recovery were present among non-HRT users. In addition, these effects were maintained after controlling for health behaviors, medications, and medical conditions.

CONCLUSION

Chronic dementia caregiving stress in combination with HRT may impair recovery of platelet activation after acute mental stress (i.e., activation levels do not quickly return to resting levels), thereby potentially increasing cardiovascular risk among CG who take HRT.

Estrogen effects on arteries vary with stage of reproductive life and extent of subclinical atherosclerosis progression

The past several years have been marked by confusion and controversy concerning whether estrogens are cardioprotective. The issue is of utmost public health importance because coronary heart disease (CHD) remains the leading cause of death among postmenopausal women. Fortunately, a unifying hypothesis has emerged that reproductive stage is a major determinant of the effect of estrogens on atherosclerosis progression, complications, and plaque vulnerability. PREMENOPAUSAL YEARS: Premenopausal atherosclerosis progression seems to be an important determinant of postmenopausal atherosclerosis and thus the risk for CHD. Clearly, plasma lipids/lipoproteins influence this progression; however, estradiol deficiency seems to be the major modulator. Both monkeys and women with premenopausal estrogen deficiency develop premature atherosclerosis, an effect that can be prevented in both species by estrogen-containing oral contraceptives. PERIMENOPAUSAL/EARLY POSTMENOPAUSAL YEARS: During this stage, there are robust estrogen benefits. Monkeys given estrogens immediately after surgical menopause have a 70% inhibition in coronary atherosclerosis progression. Estrogen treatment prevented progression of atherosclerosis of women in the Estrogen in the Prevention of Atherosclerosis Trial. A meta-analysis of women younger than 60 years given hormone therapy had reduced total mortality (relative risk = 0.61, 95% CI: 0.39-0.95). LATE POSTMENOPAUSAL YEARS: This stage is one in which there are no or possible deleterious estrogen effects. Monkeys lose CHD benefits of estrogens when treatment is delayed. The increase in CHD events associated with initiating hormone therapy 10 or more years after menopause seems to be related to up-regulation of the plaque inflammatory processes and plaque instability and may be down-regulated by statin pretreatment.

Therapeutic regulation of endothelial dysfunction in type 2 diabetes mellitus

Endothelial dysfunction is universal in diabetes, being intimately involved with the development of cardiovascular disease. The pathogenesis of endothelial dysfunction in diabetes is complex. It is initially related to the effects of fatty acids and insulin resistance on 'uncoupling' of both endothelial nitric oxide synthase activity and mitochondrial function. Oxidative stress activates protein kinase C (PKC), polyol, hexosamine and nuclear factor kappa B pathways, thereby aggravating endothelial dysfunction. Improvements in endothelial function in the peripheral circulation in diabetes have been demonstrated with monotherapies, including statins, fibrates, angiotensin-converting enzyme (ACE) inhibitors, metformin and fish oils. These observations are supported by large clinical end point trials. Other studies show benefits with certain antioxidants, L-arginine, folate, PKC-inhibitors, peroxisome proliferator activated receptor (PPAR)-alpha and -gamma agonists and phosphodiesterase (PDE-5) inhibitors. However, the benefits of these agents remain to be shown in clinical end point trials. Combination treatments, for example, statins plus ACE inhibitors and statins plus fibrates, have also been demonstrated to have additive benefits on endothelial function in diabetes, but there are no clinical outcome data to date. Measurement of endothelial dysfunction in cardiovascular research can provide fresh opportunities for exploring the mechanism of benefit of new therapeutic regimens and for planning and designing large clinical trials.

Cardiovascular disease in diabetic nephropathy patients: cell adhesion molecules as potential markers?

Cardiovascular disease is a major complication of diabetes mellitus, especially for patients with diabetic nephropathy. The underlying factor or pathogenic mechanism that links diabetic nephropathy with cardiovascular disease is not known. The endothelial cell adhesion molecules, intercellular adhesion molecule-1 or vascular cell adhesion molecule-1, play a crucial role in the initiation of atherosclerosis. Levels of both cell adhesion molecules are raised by the diabetic and kidney disease states. This review focuses on these important cell adhesion molecules and their role in the pathogenesis of cardiovascular disease in diabetes and diabetic nephropathy.

Combined therapy with ramipril and simvastatin has beneficial additive effects on tissue factor activity and prothrombin fragment 1+2 in patients with type 2 diabetes

Tissue factor (TF) plays a pivotal role in thrombus formation. Statins and angiotensin converting enzyme inhibitors attenuate expression of TF by distinct mechanism. Therefore, we hypothesized that combined therapy with simvastatin and ramipril may have additive beneficial anti-atherogenic effects to lower TF activity when compared with either drug alone. This was a randomized, double-blind, placebo-controlled cross-over trial with three treatment arms (each 2 months) and two washout periods (each 2 months). Fifty patients with type 2 diabetes were given simvastatin 20 mg and placebo, simvastatin 20 mg and ramipril 10 mg, or ramipril 10 mg and placebo daily during each treatment period. Simvastatin and ramipril monotherapy tended to reduce TF activity (0.53 to 0.46 nM, P=0.056; 0.54 to 0.50 nM, P=0.167, respectively) while combined therapy had a significant effect (0.64 to 0.43 nM, P<0.001). All three therapies significantly reduced prothrombin fragment 1+2 (F1+2) levels from their respective baselines (P=0.037, P<0.001, and P=0.057, respectively). Combined therapy significantly reduced TF activity and F1+2 levels to a greater extent than either simvastatin or ramipril alone (P=0.029 and P=0.040 by ANOVA, respectively). Percent changes in TF activity and percent changes in F1+2 levels were significantly correlated. All three therapies reduced CD40 ligand levels from their respective baselines (P=0.098, P<0.001, and P=0.002, respectively) with no significant differences among these three therapies (P=0.204 by ANOVA). Ramipril combined with simvastatin significantly reduces plasma TF activity and F1+2 levels to a greater extent than monotherapy with either drug in patients with type 2 diabetes.

Biochemical markers surrogating on vascular effects of sex steroid hormones

The main mechanism of possible cardioprotection by estrogens appears to be a direct effect on the vasculature, resulting in an improvement of endothelial function and inhibition of atherogenesis. Numerous observational and experimental studies have demonstrated a positive correlation between estrogens and various biochemical markers surrogating direct vascular effects. In general, most markers are influenced in a similar way by oral and transdermal hormone therapy, although oral therapy may have a faster and more pronounced effect. The main difference between oral and transdermal administration may be confined to markers that are mainly or exclusively produced in the liver. Clinical studies demonstrate that progestogen addition can have an impact on the beneficial estrogen-induced changes of biochemical markers. Concerning the effects of tibolone, inconsistent data have been found. Overall, tibolone-induced beneficial changes on the various biochemical markers appear to be less marked compared with those of hormone therapy. The few data available on the direct effects of androgens on the vascular wall indicate a less favorable action of androgens on biochemical markers than of estrogens. The practical relevance of marker measurements is currently under discussion. Although evidence strongly supports some of these markers as predictors of acute events, it remains to be established whether modifying circulating levels of these markers will influence outcomes.

Oestrogen and stroke in women: assessment of risk

The Women's Health Initiative reported an increased risk of stroke with hormone therapy, which has had a major effect on the use of these drugs. The increased risk was unexpected because research with animals showed that oestrogen reduces the extent of experimental strokes, and in human beings, oestrogen improves endothelial-dependent blood flow and lipid profiles. The mechanisms of risk might be related to oestrogen's proinflammatory and prothrombotic effects. However, the overall risk is still uncertain because of the complex actions of oestrogen at different doses, with or without progesterone, and the presence or absence of atherosclerotic risk factors. A similar debate about oral contraceptives and stroke risk in young women continues as data accumulate. Further studies are needed to identify the mechanisms of risk of stroke with oestrogen, as well as the risk factors that put women at particularly high risk of stroke with these hormones.

Significant differential effects of lower doses of hormone therapy or tibolone on markers of cardiovascular disease in post-menopausal women: a randomized, double-blind, crossover study

AIMS

We have previously reported that lower doses of hormone therapy (L-HT) and tibolone have different effects on markers of cardiovascular disease when compared with conventional doses of HT. The objective was to compare the effects of L-HT and tibolone on lipid profile, vasodilation, and factors associated with inflammation and haemostasis.

METHODS AND RESULTS

Forty-one women received a combination of micronized progesterone 100 mg with conjugated equine estrogen 0.3 mg vs. tibolone 2.5 mg alone daily in random order during 2 months with 2 months washout period. When compared with L-HT, tibolone significantly reduced total cholesterol (P<0.001), triglyceride (P<0.001), HDL cholesterol (P<0.001) levels, and triglyceride/HDL cholesterol ratios (P=0.004) except total cholesterol/HDL cholesterol ratios. Tibolone improved flow-mediated response to hyperaemia from baseline values (P<0.001) by a similar magnitude to L-HT. L-HT and tibolone did not increase high-sensitivity C-reactive protein relative to baseline values. L-HT reduced antithrombin III from baseline values (P=0.037), compared with tibolone showing no changes. However, there was no difference between either. In contrast, tibolone increased pro-thrombin fragment 1+2 (F1+2) from baseline values (P=0.002), compared with L-HT showing no changes. Tibolone significantly reduced plasma plasminogen activator inhibitor type 1 (PAI-1) antigen levels from baseline values (P=0.004), compared with L-HT showing no changes. The effects of L-HT and tibolone on F1+2 and PAI-1 were significantly different (P=0.045 and P=0.008, respectively).

CONCLUSION

Both tibolone and L-HT improved flow-mediated response by a similar magnitude and did not significantly increase high-sensitivity C-reactive protein. However, tibolone significantly reduced PAI-1, but increased F1+2 more than L-HT.

Long-term hormone replacement therapy delays the age related progression of carotid intima-media thickness in healthy postmenopausal women

OBJECTIVES

Carotid intima-media thickness (IMT) is an appropriate intermediate end point to investigate clinically relevant effects on atherogenesis. The study objective was to clarify whether long-term hormone replacement therapy (HRT) modifies the progress of age-related IMT in healthy postmenopausal Japanese women.

METHODS

One hundred and eighty-eight healthy postmenopausal women aged 42-69 years were recruited into the retrospective study. IMT was measured by B-mode real-time ultrasound in the following three groups of patients. One hundred and fifteen women who were prescribed estrogen plus progestin or estrogen alone were classified into two groups according to the HRT treated period: short-term (<2 years of treatment, n = 52) and long-term (> or =2 years, n = 63) HRT groups. The third group consisted an age-matched women (n = 73), who were never treated with HRT (non-HRT group) as a control.

RESULTS

Each group was divided into three subgroups according to age: < or =49 years, 50-59 years and 60 years or older. IMT in patients of age > or =60 years in the non-HRT group was 0.607 +/- 0.064 mm and was significantly higher compared with that in the other two age subgroups of non-HRT patients (< or =49 years: [0.495 +/- 0.051 mm; 50-59 years: 0.505 +/- 0.068 mm) (P < 0.05). In the short-term HRT group, IMT of > or =60-year-old-subjects (0.588 +/- 0.074 mm) was also significantly higher compared with that in the other two age subgroups (< or =49 years: 0.480 +/- 0.034 mm; 50-59 years: 0.511 +/- 0.062 mm). However, in the long-term HRT group, IMT was not significantly different among the three age subgroups. There was a significant relationship between IMT and age in non-HRT (r = 0.594, P < 0.0001) and short-term HRT (r = 0.542, P < 0.001) groups, but no significant relationship was observed in the long-term HRT (r = 0.195 , P = 0.1266) group.

CONCLUSIONS

In long-term HRT, more than 2 years may delay the age-related increase in IMT in healthy postmenopausal Japanese women.

Assessment of flow-mediated vasodilatation (FMD) of the brachial artery: effects of technical aspects of the FMD measurement on the FMD response

AIMS

The ability to assess endothelial function non-invasively with B-mode ultrasound has lead to its widespread application in a variety of studies. However, the absolute values obtained using this approach vary considerably across studies. We studied whether technical aspects of the methodology can explain the wide variety in absolute values across studies.

METHODS AND RESULTS

A literature search was performed to identify published reports on flow-mediated vasodilatation (FMD) of the brachial artery published between 1992 and 2001. Information on type of equipment (wall track/B-mode), location of the measurement (antecubital fossa/upper arm), occlusion site (lower/upper arm), occlusion duration (min), and occlusion pressure was extracted. Patient characteristics were also extracted. For the healthy populations, mean FMD varied from 0.20 to 19.2%; for the coronary heart disease (CHD) patients FMD varied from -1.3 to 14%; for subjects with diabetes mellitus FMD varied from 0.75 to 12%. Compared with occlusion at the upper arm, lower arm occlusion was related to decreased FMD (mean difference in FMD -2.47%; 95% CI 0.55-4.39). An occlusion duration of > or =4.5 min was related to an increased FMD compared with an occlusion time of < or =4 min (mean difference 1.30%; 95% CI 0.35-2.46). These findings were adjusted for other technical aspects of the methodology and for differences in risk factors between populations.

CONCLUSION

Mean FMD differs widely between studies. There is a great overlap between populations (healthy, CHD, diabetics). Our findings suggest that the technical aspects of the measurements, the location, and the duration of the occlusion may explain some of these differences, whereas type of equipment, location of the measurement, and occlusion pressure do not.

Effects of low-dose continuous combined HRT on vascular function in women with type 2 diabetes

BACKGROUND

Improvement in vascular endothelial function is widley cited as a beneficial effect of hormone replacement therapy (HRT). Women with type 2 diabetes (T2DM) are at increased cardiovascular risk and have impaired endothelial function. Any benefits of HRT on endothelial function in this group are of particular interest.

OBJECTIVES

We assessed effects on vascular function of oral 17beta oestradiol (1 mg) and norethisterone (0.5 mg) in postmenopausal women with T2DM.

DESIGN

Double-blind, randomised, placebo-controlled trial.

ASSESSMENTS

Twenty-eight women had pulse wave velocity (PWV) and adhesion molecules VCAM-1 and ICAM-1 assessed before and after three months' treatment. Twenty-four women also had gluteal fat biopsy for assessment of resistance vessel function (using wire myography).

RESULTS

HRT did not affect PWV, VCAM-1, ICAM-1 or carbachol response. Effects of L-NAME and indomethacin on carbachol sensitivity were similar in both groups.

CONCLUSIONS

This HRT preparation had no detectable effect on these measures of endothelial function in women with T2DM.

Effects of Conventional or Lower Doses of Hormone Replacement Therapy in Postmenopausal Women

OBJECTIVE

The effects of hormone replacement therapy (HRT) can affect many aspects relevant to cardiovascular disease, including vasomotor function, inflammation, and hemostasis. Recent studies have demonstrated that current doses of HRT exert a mixture of both protective and adverse effects. In the current study, we compared the effects of lower doses of HRT (L-HRT) and conventional doses of HRT (C-HRT) on a variety of relevant cardiovascular parameters.

METHODS AND RESULTS

This randomized, double-blind, crossover study included 57 women who received micronized progesterone 100 mg with either conjugated equine estrogen 0.625 mg (C-HRT) or 0.3 mg (L-HRT) daily for 2 months. L-HRT showed comparable effects to C-HRT on high-density lipoprotein cholesterol and triglyceride levels, but not on low-density lipoprotein cholesterol levels. C-HRT and L-HRT significantly improved the percent flow-mediated dilator response to hyperemia from baseline values (both P<0.001) by a similar degree (P=0.719). C-HRT significantly increased high-sensitivity C-reactive protein (hsCRP) levels from baseline values (P<0.001); however, L-HRT did not significantly change hsCRP (P=0.874). C-HRT and L-HRT significantly decreased antithrombin III from baseline values (P<0.001 and P=0.042, respectively). C-HRT significantly increased prothrombin fragment 1+2 (F1+2) from baseline values (P<0.001); however, L-HRT did not significantly change F1+2 (P=0.558). Of interest, the effects of C-HRT and L-HRT on hsCRP, antithrombin III, and F1+2 were significantly different (all P<0.001). C-HRT and L-HRT significantly reduced plasma PAI-1 antigen levels from baseline values (P=0.002 and P=0.038, respectively) to a similar degree (P=0.184).

CONCLUSIONS

Compared with C-HRT, L-HRT has comparable effects on lipoproteins, flow-mediated dilation, and PAI-1 antigen levels. However, L-HRT did not increase hsCRP or F1+2 levels, and it decreased antithrombin III less than C-HRT.

Should Progestins Be Blamed for the Failure of Hormone Replacement Therapy to Reduce Cardiovascular Events in Randomized Controlled Trials?

Many observational studies and experimental and animal studies have demonstrated that estrogen replacement therapy (ERT) or hormone replacement therapy (HRT) (estrogen plus progestin) significantly reduces the risk of coronary heart disease. Nonetheless, recent randomized controlled trials demonstrated some trends toward an increased risk of cardiovascular events rather than a reduction of risk. Recently, both the HRT and ERT arms of the Women’s Health Initiative (WHI) study were terminated early because of an increased/no incidence of invasive breast cancer, increased incidence of stroke, and increased trend/no protective effects of cardiovascular disease. We discuss the controversial effects of HRT and ERT on cardiovascular system and provide a hypothesis that the failure of HRT and ERT in reducing the risk of cardiovascular events in postmenopausal women might be because of the stage of their atherosclerosis at the time of initiation of HRT or ERT.

Effect of hormone replacement therapy on cardiovascular risk factors in postmenopausal women with diabetes

BACKGROUND

Hormone replacement therapy (HRT) in postmenopausal women improves menopausal symptoms, decreases the incidence of osteoporotic fracture, but the effects on cardiovascular risk factors remain controversial.

AIM

To test the hypothesis that HRT may have beneficial effects on the cardiovascular risk profile in postmenopausal women with diabetes.

METHODS

One hundred and fifty postmenopausal patients with type 1 (T1DM) and type 2 diabetes (T2DM) were randomized to receive HRT (Kliofem) or placebo for 12 months. We monitored the effects on cardiovascular risk factors, including lipid profile, glycaemic control, blood pressure and body weight.

RESULTS

Mean low-density lipoprotein (LDL) cholesterol was associated with a nonsignificant decrease [-0.14 mmol/l (CI=-0.44, 0.17) (p=0.37)] in the Kliofem-treated group. Total cholesterol fell by 0.42 mmol/l (CI=-0.78, -0.05) (p=0.027). High-density lipoprotein (HDL) cholesterol was reduced by a mean of 0.07 mmol/l compared to a mean rise of 0.12 mmol/l on placebo. There were apparent differences in the treatment effects between T1DM and T2DM. There was no change in triglycerides or apoprotein B and no effect on glycaemic control, blood pressure or menopausal symptom scores. In the Kliofem group, BMI fell by 0.66 kg/m2 compared to an increase of 0.14 kg/m2 for placebo patients (p=0.046).

CONCLUSIONS

Although the long-term effects of HRT in women with or without diabetes appear to suggest that some types of HRT either confer no cardiovascular protection or may increase risk, the impact of Kliofem diabetic women on cardiovascular risk factors is probably neutral.

The neointimal response to endovascular injury is increased in obese Zucker rats

BACKGROUND

Restenosis after revascularization procedures is accelerated in persons with type 2 diabetes.

AIM

The current study tested the hypothesis that the neointimal response to endovascular injury is enhanced in female obese Zucker (OZ) rats, a model of type 2 diabetes.

METHODS

Animals were randomized to receive either a standard diet (SD) or a diabetogenic diet (DD) for 6 weeks. Four weeks later, balloon injury of the right common carotid artery was induced. All rats were euthanized 2 weeks after injury. Lean Zucker (LZ) rats served as controls.

RESULTS

At the time of death, plasma glucose was elevated in OZ rats fed a SD (208 +/- 13 mg/dl) and a DD (288 +/- 21 mg/dl) compared to corresponding LZ rats (SD: 153 +/- 8; DD: 132 +/- 7 mg/dl). The ratio of high-density lipoprotein cholesterol (HDLc) to total cholesterol (Totc), an index of atherogenicity, was reduced in OZ rats on both diets (SD: 0.77 +/- 0.06; DD: 0.80 +/- 0.09) compared to LZ controls (SD: 1.11 +/- 0.02; DD: 1.20 +/- 0.05). Histomorphometric analysis of injured arteries showed that the intima to media (I : M) ratio was significantly increased in OZ (1.37 +/- 0.07) compared to LZ (0.79 +/- 0.08) rats. Elevations in plasma glucose and triglycerides (Tg) correlated positively and decreases in HDLc negatively with an increased I : M ratio. Administration of the DD did not further enhance the I : M ratio in LZ (0.87 +/- 0.06) or OZ (1.29 +/- 0.09) rats.

CONCLUSIONS

These results suggest that neointima formation following endoluminal injury of the carotid artery is enhanced at an early stage in the development of diabetes mellitus.

Significant differential effects of hormone therapy or tibolone on markers of cardiovascular disease in postmenopausal women: a randomized, double-blind, placebo-controlled, crossover study

OBJECTIVE

The objective was to compare the effects of tibolone and hormone therapy (HT) on lipid profile, vasodilation, and factors associated with inflammation and hemostasis.

METHODS AND RESULTS

Fifty-three women received micronized progesterone (MP, 100 mg) with conjugated equine estrogen (CEE, 0.625 mg) or tibolone (2.5 mg) daily for 2 months, with a 2-month washout period. Compared with HT, tibolone significantly reduced total cholesterol (P<0.001), triglyceride (P<0.001), and HDL cholesterol (P<0.001) levels as well as triglyceride/HDL cholesterol ratios (P<0.001) but not LDL cholesterol levels. Tibolone significantly improved flow-mediated brachial artery dilator response to hyperemia from baseline values (P<0.001) by a magnitude similar to that found with HT (P=0.628). Compared with tibolone, which showed no changes, HT significantly increased high-sensitivity C-reactive protein (hsCRP, P=0.030) and reduced antithrombin III (P<0.001). HT and tibolone significantly increased prothrombin fragment 1+2 (F1+2) from baseline values (P<0.001 and P=0.004, respectively). The effects of HT and tibolone on hsCRP, antithrombin III, and F1+2 were significantly different. HT and tibolone significantly reduced plasma levels of plasminogen activator inhibitor type 1 antigen from baseline levels (P=0.006 and P=0.005, respectively) to a similar degree (P=0.988).

CONCLUSIONS

Tibolone significantly improved flow-mediated brachial artery dilator response by a magnitude similar to that found with CEE+MP; however, tibolone did not significantly change hsCRP and antithrombin III, and tibolone increased F1+2 less than did CEE+MP.

Increased levels of C-reactive protein after oral hormone replacement therapy may not be related to an increased inflammatory response

BACKGROUND

It has been suggested that hormone replacement therapy (HRT) in postmenopausal women is associated with an increased inflammatory response that may trigger acute cardiovascular events. This suggestion is mainly based on the finding of elevated C-reactive protein (CRP) levels after HRT. The aim of the present study was to evaluate a broad spectrum of vascular inflammation markers in 389 postmenopausal women with increased cardiovascular risk at baseline and after either 6 months of HRT (126 women) or no HRT (263 women).

METHODS AND RESULTS

Compared with baseline, CRP levels significantly increased after HRT (0.9+/-0.2 versus 1.6+/-0.4 mg/L, P<0.01); on the contrary, soluble intracellular adhesion molecule-1 decreased from 208+/-57 to 168+/-37 ng/mL (P<0.01) after HRT. Similarly, vascular cell adhesion molecule-1 decreased from 298+/-73 to 258+/-47 ng/mL (P<0.01), plasma E-selectin levels were reduced from 17.8+/-5.6 to 14.8+/-3.9 ng/mL (P<0.01), interleukin-6 levels decreased from 1.51+/-0.22 to 1.29+/-0.28 pg/mL, and s-thrombomodulin plasma levels decreased from 4.8+/-0.7 to 4.3+/-0.9 ng/mL (P<0.01). No significant changes in either CRP or vascular inflammatory marker were detected in women not taking HRT.

CONCLUSIONS

The discrepancy between increased plasma levels of CRP and reduced plasma levels of all other markers of inflammation suggests that the increased CRP levels after oral HRT may be related to metabolic hepatic activation and not to an acute-phase response. HRT seems to be associated with an overall decrease in vascular inflammation.

Detection of endothelial dysfunction with brachial artery ultrasound scanning

The role of the endothelium in human disease recently has become the focus of intense scientific investigation. Impaired endothelial function is associated with a number of disease states, including cardiovascular disease (CVD) and its major risk factors. Endothelial dysfunction precedes overt vascular disease by years and may itself be a potentially modifiable CVD risk factor. Although no gold standard for the measurement of endothelial function exists, the measurement of flow-mediated dilation (FMD) in the brachial artery, assessed with Doppler ultrasonography, is the most studied method and shows the most promise for clinical application. It is a well-tolerated, noninvasive, and low-risk procedure. Brachial artery FMD after transient vascular occlusion may serve as an index of nitric oxide bioavailability, and its impairment correlates with coronary arterial abnormalities. These factors, with the wide availability of vascular ultrasound scanning in clinical practice, make brachial artery FMD an attractive screening tool for endothelial dysfunction. Present limitations of this procedure include the lack of a consensus definition of normal FMD and the variability among centers in both procedural technique and image analysis. However, these limitations are likely to be overcome with increasing experience and advances in technology, and with further refinements, the measurement of brachial artery FMD will likely become the clinical technique of choice for the evaluation of endothelial disease.

Does elevated body mass modify the influence of postmenopausal estrogen replacement on atherosclerosis progression: results from the estrogen in the prevention of atherosclerosis trial

OBJECTIVE

To determine whether the estrogen-related reduction in atherosclerosis progression demonstrated in the estrogen in the prevention of atherosclerosis trial (EPAT) is modified by body mass index (BMI).

STUDY DESIGN

Subgroup analyses were performed using data from EPAT, a randomized, double-blind, placebo-controlled trial designed to determine whether unopposed 17beta-estradiol administered for a 2-year treatment period reduces the progression of subclinical atherosclerosis in healthy postmenopausal women. The primary trial endpoint was the rate of change of common carotid artery intima-media thickness (IMT). In this subgroup analysis, the sample was divided into 122 women with BMI<30 kg/m(2) and 77 women with BMI> or =30 kg/m(2). Statistical analysis was performed using mixed general linear models to evaluate whether the treatment effects on IMT progression rates differed in the two BMI groups.

RESULTS

There was no significant difference in the estradiol treatment effect on IMT progression rates between postmenopausal women with BMI<30 vs. > or =30 kg/m(2) (P=0.52). In the 77 subjects who did not use lipid-lowering therapy, there was significant improvement in IMT with estradiol treatment that was evident in both BMI groups (P=0.48 for differences between BMI groups).

CONCLUSIONS

In contrast to the epidemiological observation that obese postmenopausal women do not derive benefit from estrogen replacement therapy, results of this study indicate that estradiol treatment is beneficial in preventing progression of atherosclerosis regardless of initial BMI.

CONDENSATION

Estradiol treatment is beneficial in preventing progression of atherosclerosis in postmenopausal women not receiving lipid-lowering therapy, regardless of their initial body mass index.

HRT does not improve urinary albumin excretion in postmenopausal diabetic women

The effect of 6 months combined, continuous hormone replacement therapy (HRT) with conjugated equine oestrogen (0.625 mg) and medroxyprogesterone acetate (2.5 mg) on albumin/creatinine ratio (ACR) was determined in postmenopausal diabetic women in a randomised, controlled study. Mean (interquartile range) change in plasma ACR was not (P=0.96) different in women receiving HRT [2 (-11, 21) mg/g, n=20] compared with those randomised to placebo [2 (-1, 14) mg/g, n=27]. Also, the proportion of women with microalbuminuria did not change (P=0.75) during HRT (baseline, 0.45; end of study, 0.53). Furthermore, several risk factors for microalbuminuria including systolic blood pressure (SBP), fasting blood glucose, glycated haemoglobin (HbA1c) and adiposity did not vary significantly during HRT. These data suggest that 6 months HRT does not reverse microalbuminuria caused by prolonged hyperglycaemia and other risk factors that underlie leakage of albumin into the urine in postmenopausal women with type 2 diabetes.

Effects of statin on plaque stability and thrombogenicity in hypercholesterolemic patients with coronary artery disease

OBJECTIVE

Plaque stability and thrombogenicity contribute to development and clinical expression of atherosclerosis. Experimental studies have shown that lipoproteins or mevalonate regulate matrix metalloproteinase (MMP)-9, tissue factor (TF), plasminogen activator inhibitor-1 (PAI-1) expression, providing nonlipid mechanism.

METHODS

We administered simvastatin 20 mg daily during 14 weeks to 32 hypercholesterolemic patients with coronary artery disease.

RESULTS

Compared with pretreatment values, simvastatin significantly lowered lipoprotein levels (all P<0.01). Compared with pretreatment values, simvastatin significantly lowered plasma levels of MMP-9, TF, and PAI-1 (P=0.009, P=0.032, and P=0.007, respectively). There were significant inverse correlations between pretreatment MMP-9, TF activity or PAI-1 antigen and the degree of change in those levels after simvastatin (r=-0.793, P<0.001; r=-0.482, P=0.005 and r=-0.590, P<0.001, respectively). Of interest, there were significant correlation between pretreatment or percent changes in MMP-9 levels and pretreatment or percent changes in PAI-1 antigen (r=0.293, P=0.019 and r=0.375, P=0.034, respectively). However, no significant correlations between lipoprotein levels and levels of plaque stability or thrombogenicity markers were determined.

CONCLUSIONS

Reduction of plaque stability and thrombogenicity markers with statin may contribute to the cardiovascular event reduction and explain the early clinical benefit in clinical trials, independent of lipoprotein changes.

Relation between hormone replacement therapy and ischaemic heart disease in women: prospective observational study

OBJECTIVE

To investigate the risk of ischaemic heart disease and myocardial infarction among women using hormone replacement therapy, especially the potential modifying effect of cardiovascular risk factors.

DESIGN

Prospective observational study.

SETTING

Denmark.

PARTICIPANTS

19 898 nurses aged 45 and over completing a questionnaire on lifestyle and use of hormone replacement therapy in 1993.

MAIN OUTCOME MEASURES

All cases of death and incident cases of ischaemic heart disease and myocardial infarction until the end of 1998.

RESULTS

Current users of hormone replacement therapy smoked more, consumed more alcohol, had lower self rated health, but were slimmer and had a lower prevalence of diabetes than never users. In current users compared with never users, hormone replacement therapy had no protective effect on ischaemic heart disease (hazard ratio 1.2, 0.9 to 1.7) or myocardial infarction (1.0, 0.6 to 1.7), whereas current users with diabetes had an increased risk of death (3.2, 1.4 to 7.5), ischaemic heart disease (4.2, 1.4 to 12.5), and myocardial infarction (9.2, 2.0 to 41.4) compared with never users with diabetes.

CONCLUSION

Hormone replacement therapy showed no protective effect on ischaemic heart disease, but there was a significantly increased risk of death from all causes and ischaemic heart disease among women with diabetes.

Can a healthy endothelium influence the cardiovascular effects of hormone replacement therapy?

Emerging clinical and observational evidences suggest that estrogen confers physiologic benefits that are receptor mediated and depend on the integrity and functional status of the endothelium within the coronary vasculature. In postmenopausal women, estrogen replacement therapy (ERT) and hormone replacement therapy (HRT) regimens can enhance the lipoprotein panel; blunt the expression of numerous cytokines, chemokines, and other proinflammatory mediators of endothelial injury and vascular smooth muscle cell proliferation; up-regulate endothelial nitric oxide synthase activity and nitric oxide production; and augment fibrinolysis potential and vasodilator capacity (diminish arterial resistance). Advancing age and atherosclerotic injury to the vessel wall tend to deplete estrogen receptors, compromise endothelial function, promote thrombus formation, and thus potentially diminish the efficacy of ERT and HRT. Therefore, optimizing the clinical benefits of these regimens in postmenopausal women depends largely on promoting a healthy endothelium through life-style modifications that diminish coronary risk.

Effects of continuous combined hormone replacement therapy on inflammation in hypertensive and/or overweight postmenopausal women

OBJECTIVE

We observed that estrogen did not show cardioprotective benefits in type 2 diabetic postmenopausal women. We hypothesized that hypertensive and/or overweight women may be less likely to realize cardiovascular benefits from estrogen.

METHODS AND RESULTS

We administered micronized progesterone (MP) 100 mg or medroxyprogesterone acetate (MPA) 2.5 mg with conjugated equine estrogen (CEE) 0.625 mg daily during 2 months to 35 hypertensive and/or overweight postmenopausal women with a randomized, double-blind, crossover design. With significant changes of lipoproteins, CEE+MP or MPA significantly improved flow-mediated dilation and reduced plasma E-selectin, intercellular adhesion molecule type-1, monocyte chemoattractant protein-1, and tumor necrosis factor-alpha levels (P<0.001, P<0.001, P=0.021, P<0.001, and P<0.001 by ANOVA, respectively), but not C-reactive protein and fibrinogen levels. Of note, there were no significant differences between each therapy regarding these effects. However, the magnitude of improvement of flow-mediated dilation in these women was less than in healthy postmenopausal women and more than in diabetic postmenopausal women reported by our previous studies. The effects of CEE+MP or MPA on inflammatory markers were comparable to healthy postmenopausal women, but not comparable to diabetic postmenopausal women.

CONCLUSIONS

Estrogen combined with synthetic progestin significantly improved flow-mediated brachial artery dilator response and reduced inflammation markers in hypertensive and/or overweight women, comparable to estrogen combined with natural progesterone.

Estrogen has opposing effects on vascular reactivity in obese, insulin-resistant male Zucker rats

We hypothesized that estradiol treatment would improve vascular dysfunction commonly associated with obesity, hyperlipidemia, and insulin resistance. A sham operation or 17beta-estradiol pellet implantation was performed in male lean and obese Zucker rats. Maximal vasoconstriction (VC) to phenylephrine (PE) and potassium chloride was exaggerated in control obese rats compared with lean rats, but estradiol significantly attenuated VC in the obese rats. Estradiol reduced the PE EC50 in all groups. This effect was cyclooxygenase independent, because preincubation with indomethacin reduced VC response to PE similarly in a subset of control and estrogen-treated lean rats. Endothelium-independent vasodilation (VD) to sodium nitroprusside was similar among groups, but endothelium-dependent VD to ACh was significantly impaired in obese compared with lean rats. Estradiol improved VD in lean and obese rats by decreasing EC50 but impaired function by decreasing maximal VD. The shift in EC50 corresponded to an upregulation in nitric oxide synthase III protein expression in the aorta of the estrogen-treated obese rats. In summary, estrogen treatment improves vascular function in male insulin-resistant, obese rats, partially via an upregulation of nitric oxide synthase III protein expression. These effects are counteracted by adverse factors, such as hyperlipidemia and, potentially, a release of an endothelium-derived contractile agent.