Estrogen replacement reverses endothelial dysfunction in postmenopausal women

Sex Differences in the Inflammatory Response: Pharmacological Opportunities for Therapeutics for Coronary Artery Disease

Coordinated molecular responses are key to effective initiation and resolution of both acute and chronic inflammation. Vascular inflammation plays an important role in initiating and perpetuating atherosclerotic disease, specifically at the site of plaque and subsequent fibrous cap rupture. Both men and women succumb to this disease process, and although management strategies have focused on revascularization and pharmacological therapies in the acute situation to reverse vessel closure and prevent thrombogenesis, data now suggest that regulation of host inflammation may improve both morbidity and mortality, thus supporting the notion that prevention is better than cure. There is a clear sex difference in the incidence of vascular disease, and data confirm biological differences in inflammatory initiation and resolution between men and women. This article reviews contemporary opinions describing the sex difference in the initiation and resolution of inflammatory responses, with a view to explore potential targets for pharmacological intervention.

ETB receptor contribution to vascular dysfunction in postmenopausal women

Endothelin-1 (ET-1) contributes to age-related endothelial dysfunction in men via the ET_A receptor. However, there are sex differences in the ET-1 system, and ET_B receptors are modulated by sex hormones. The purpose of this study was to test the hypothesis that ET_B receptors contribute to impaired vasodilatory function in postmenopausal women (PMW). We measured flow-mediated dilation (FMD) using ultrasound, and cutaneous nitric oxide-mediated vasodilation during local heating (42°C) via laser Doppler flowmetry in 18 young women (YW; 22 ± 1 yr) and 16 PMW (56 ± 1 yr). Cutaneous microdialysis perfusions of lactated Ringer (control), an ET_B receptor antagonist (BQ-788, 300 nM), and an ET_A receptor antagonist (BQ-123, 500 nM), were done through separate fibers, followed by perfusions of sodium nitroprusside (28 mM) and local heating to 43°C (max). Cutaneous vascular conductance (CVC) was calculated as cutaneous blood flow/mean arterial pressure and expressed as a percent of maximal dilation. FMD (YW: 7.5 ± 0.5 vs. PMW: 5.6 ± 0.6%) and cutaneous vasodilation (YW: 93 ± 2 vs. PMW: 83 ± 4%CVC_max) were lower in PMW (both P < 0.05). Blockade of ET_B receptors decreased cutaneous vasodilation in YW (87 ± 2%CVC_max; P < 0.05 vs. control) but increased vasodilation in PMW (93 ± 1%CVC_max; P < 0.05 vs. control). ET_A receptor blockade had minimal effect in YW (92 ± 1%CVC_max) but increased cutaneous vasodilation in PMW (91 ± 2%CVC_max; P < 0.05 vs. control). In conclusion, ET_B receptors mediate vasodilation in YW, but this effect is lost after menopause. Impaired vasodilatory function in PMW is due in part to a loss of ET_B-mediated dilation.

Vasodilator prostanoids compensate for attenuated nitric oxide mediated vasodilation in type 1 diabetes

Background Previous research examining endothelial function and the biochemical pathways mediating vasodilation in type 1 diabetes has been conflicting. Both impaired and preserved nitric oxide (NO) mediated vasodilation have been reported whilst some authors have suggested enhanced vasodilator prostanoid (P) activity. The aim of this study was to determine the relative contributions of NO and P to endothelial function in a homogenous group of type 1 diabetic patients free of other confounding factors that may influence vascular behaviour.^f ^

Methods and results Endothelial function was assessed using forearm venous plethysmography in 16 patients with uncomplicated type 1 (duration of diabetes 16.8±2.5 years (mean±SEM), HbA1C 7.53±0.21% ) and 15 non-diabetic age and sex matched healthy control subjects. Forearm responses to the endothelium-dependent vasodilator, acetylcholine (ACh) (7.5, 15 and 30 µg/min), were recorded at baseline and after intra-arterial infusion of L-NMMA (a NO synthase inhibitor). Responses to ACh were re-examined following co-infusion of L-NMMA and indomethacin (a cyclo-oxygenase inhibitor). Responses to ACh were calculated as areas under the curve (AUC). At baseline vasodilator responses to ACh were similar (p=0.3) in diabetic and non-diabetic subjects. However, L-NMMA reduced ACh mediated responses to a lesser extent in diabetic subjects than control subjects (3±6% versus 18±3%; p<0.03 respectively). Co-infusion with indomethacin further reduced blood flow, but the relative decrease in AUC was greater in the diabetic group (28±3% vs. 14±3%; p<0.001). The contribution of biochemical pathways other than NO and P were similar in both diabetic and control groups (69±7% vs. 68±4%; p=0.45).

Conclusions Vasodilator responses to ACh were unchanged in type 1 diabetes but this was reliant up on enhanced P mediated activity compensating for attenuated NO activity. Furthermore, vasoactive substances in addition to NO and P contribute significantly to vascular tone in both diabetic and non-diabetic subjects.

Peripheral Microvascular Vasodilatory Response to Estradiol and Genistein in Women with Insulin Resistance

OBJECTIVE

E2 enhances vasodilation in healthy women, but vascular effects of the phytoestrogen GEN are still under investigation. IR compromises microvascular function. We therefore examined the interaction of E2 , GEN, and IR on microvascular vasodilatory responsiveness.

METHODS

We hypothesized that E2 and GEN increase microvascular vasodilation in healthy women (control, n = 8, 23 ± 2 year, BMI: 25.9 ± 2.9 kg/m2) but not in women with IR (n = 7, 20 ± 1 year, BMI: 27.3 ± 3.0 kg/m2). We used the cutaneous circulation as a model of microvascular vasodilatory function. We determined CVC with laser Doppler flowmetry and beat-to-beat blood pressure during local cutaneous heating (42 °C) with E2 or GEN microdialysis perfusions. Because heat-induced vasodilation is primarily an NO-mediated response, we examined microvascular vasodilation with and without L-NMMA.

RESULTS

In C, E2 enhanced CVC (94.4 ± 2.6% vs. saline 81.6 ± 4.2% CVCmax , p < 0.05), which was reversed with L-NMMA (80.9 ± 7.8% CVCmax , p < 0.05), but GEN did not affect vasodilation. Neither E2 nor GEN altered CVC in IR, although L-NMMA attenuated CVC during GEN.

CONCLUSIONS

Our study does not support improved microvascular responsiveness during GEN exposure in healthy young women, and demonstrates that neither E2 nor GEN improves microvascular vasodilatory responsiveness in women with IR.

The effect of hormone therapy on biochemical and ultrasound parameters associated with atherosclerosis in 46,XY DSD individuals with female phenotype

The aim of this study was to evaluate the effect of hormone therapy (HT) in the endothelial function of 46,XY disorders of sexual development (DSD) patients with female phenotype. Biochemical and ultrasound measurements were performed in 20 patients at initiation of oral 2 mg 17β-estradiol/1 mg norethisterone acetate, and after 6 months of therapy. Lipid profile, including total cholesterol (TC), LDL, HDL, triglycerides (TG) and Atherogenic Index of Plasma (AIP), as well as levels of VE-Cadherin, E-Selectin, Thrombomodulin and vWf were determined. Ultrasonographic examinations included evaluation of flow-mediated dilatation (FMD) and measurement of Carotid and Femoral Intima Media Thickness (IMT). HT raised HDL (35.4 mg/dl versus 40.1 mg/dl, p = 0.019) while lowering TG (166 mg/dl versus 109 mg/dl, p = 0.026) and AIP (0.24 versus 0.04, p = 0.007). No changes were noted in TC and LDL (215.7 mg/dl versus 192.25 mg/dl and 87.46 mg/dl versus 76.35 mg/dl, respectively). There was significant reduction of VE-Cadherin (4.05 ng/ml versus 2.20 ng/ml, p = 0.002) and E-selectin (73.98 ng/ml versus 56.73 ng/ml, p = 0.004). No change was observed in Thrombomodulin and vWf (11.76 ng/ml versus 13.90 ng/ml and 80.75% versus 79.55%, respectively). FMD improved significantly (5.4% versus 8.15%, p = 0.003), while only carotid bulb IMT decreased significantly (0.65 mm versus 0.60 mm, p = 0.018). Overall, HT was found to improve biochemical and ultrasound markers of endothelial function in 46,XY DSD patients with female phenotype.

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.

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.

Ethanolic extract of rhizome of Ligusticum chuanxiong Hort. (chuanxiong) enhances endothelium-dependent vascular reactivity in ovariectomized rats fed with high-fat diet

Rhizome of Ligusticum chuanxiong Hort. (LC), also known as chuanxiong, is a very common herb widely used to treat cardiovascular and cerebrovascular diseases.

Modulation of vascular tone control under isometric muscular stress: role of estrogen receptors

AIMS

The aim of this study was to evaluate isometric muscle contraction (handgrip) changes on key elements of cardiac afterload, before and after raloxifene administration in postmenopausal women.

METHODS/RESULTS

12 postmenopausal and 12 fertile women were studied. Postmenopausal women underwent raloxifene administration (60 mg/day for 30 days). We evaluated vascular reactivity in superficial palmar arterial arch during handgrip in postmenopausal women before and after (M+R) drug administration, and in controls. Blood flow was higher after raloxifene administration (p<0.05). Mean arterial pressure (MAP)/mean arterial flow (Fmed) and arterial pulse pressure (APP)/systolic maximum arterial flow (Fmax syst) were lower after raloxifene administration (p<0.001). Systolic blood pressure (SBP)/R-R ratio was higher in postmenopausal women than in the controls and M+R (p<0.01). End-handgrip systolic and diastolic blood pressure were higher in patients before raloxifene administration than in controls (p<0.001); diastolic and mean arterial pressure reduced after raloxifene administration (p<0.001). End-effort APP/Fmax syst-ratio before treatment was higher than baseline (p<0.05). Controls and no-treated patients showed a MAP/Fmed ratio at end-handgrip higher than M+R group and rest (p<0.05). Handgrip reduced R-R interval and increased SBP/R-R ratio were shown in all groups (p<0.05).

CONCLUSIONS

Raloxifene reduced the vascular effects of isometric muscle contraction by modulating the vasomotor tone of peripheral vessels in relation to exercise.

Exposure to isoflavone-containing soy products and endothelial function: a Bayesian meta-analysis of randomized controlled trials

BACKGROUND AND AIMS

To determine whether and to what degree exposure to isoflavone-containing soy products affects EF. Endothelial dysfunction has been identified as an independent coronary heart disease risk factor and a strong predictor of long-term cardiovascular morbidity and mortality. Data on the effects of exposure to isoflavone-containing soy products on EF are conflicting.

METHODS AND RESULTS

A comprehensive literature search was conducted using the PUBMED database (National Library of Medicine, Bethesda, MD) inclusively through August 21, 2009 on RCTs using the keywords: soy, isoflavone, phytoestrogen, EF, flow mediated vasodilation, and FMD. A Bayesian meta-analysis was conducted to provide a comprehensive account of the effect of isoflavone-containing soy products on EF, as measured by FMD. A total of 17 RCTs were selected as having sufficient data for study inclusion. The overall mean absolute change in FMD (95% Bayesian CI) for isoflavone-containing soy product interventions was 1.15% (-0.52, 2.75). When the effects of separate interventions were considered, the treatment effect for isolated isoflavones was 1.98% (0.07, 3.97) compared to 0.72% (-1.39, 2.90) for isoflavone-containing soy protein. The models were not improved when considering study-specific effects such as cuff measurement location, prescribed dietary modification, and impaired baseline FMD.

CONCLUSIONS

Cumulative evidence from the RCTs included in this meta-analysis indicates that exposure to soy isoflavones can modestly, but significantly, improve EF as measured by FMD. Therefore, exposure to isoflavone supplements may beneficially influence vascular health.

Metabolic and cardiovascular outcomes in a group of adult patients with Turner's syndrome under hormonal replacement therapy

OBJECTIVE

Turner's syndrome (TS) is a rare genetic disorder caused by complete or partial X chromosome monosomy in a phenotypic female, and it is associated with increased morbidity and mortality for cardiovascular diseases, impaired glucose tolerance, and dyslipidemia.

SUBJECTS AND METHODS

In 30 adult TS patients under chronic hormonal replacement therapy (HRT), 17β-estradiol (E(2)), body mass index (BMI), waist circumference, fasting glucose and insulin, homeostatic model assessment (HOMA) index, serum lipids, oral glucose tolerance test (OGTT), 24 h ambulatory blood pressure monitoring (ABPM), and intima-media thickness (IMT) were evaluated and compared with those in 30 age- and sex-matched controls (CS).

RESULTS

No difference was found between TS and CS in E(2) and BMI, whereas waist circumference was higher (P<0.05) in TS (77.7±2.5 cm) than in CS (69.8±1.0 cm). Fasting glucose in TS and in CS was similar, whereas fasting insulin, HOMA index, and 2 h glucose after OGTT were higher (P<0.0005) in TS (13.2±0.8 mUI/l, 2.5±0.2, and 108.9±5.5 mg/dl respectively) than in CS (9.1±0.5 mUI/l, 1.8±0.1, and 94.5 ± 3.8 mg/dl respectively). Total cholesterol was higher (P<0.05) in TS (199.4 ± 6.6 mg/dl) than in CS (173.9±4.6 mg/dl), whereas no significant differences in high-density lipoprotein, low-density lipoprotein, and triglycerides were found between the two groups. In 13% of TS, ABPM showed arterial hypertension, whereas IMT was <0.9 mm in all TS and CS. A negative correlation between insulin levels, HOMA index, or 2 h glucose after OGTT and E(2) was present in TS.

CONCLUSIONS

Our results indicate that adult patients with TS under HRT are connoted by higher frequency of central obesity, insulin resistance, hypercholesterolemia, and hypertension.

Gender differences in vascular function and insulin sensitivity in young adults

To examine influence of insulin resistance and other clinical risk factors for the MetS (metabolic syndrome) on vascular structure and function in young adults. This cross-sectional study was conducted in a cohort of young adults (mean age 22 years) and their siblings participating in a longitudinal study of cardiovascular risk (n=370). Insulin sensitivity was determined by euglycaemic insulin clamp. EDD (endothelium-dependent dilation) was determined by flow-mediated dilation using high-resolution ultrasound imaging of the brachial artery. EID (endothelium-independent dilation) was determined by NTG (nitroglycerine)-mediated dilation. The diameter and cIMT (intima-media thickness) of the carotid artery were also measured. There was no significant difference between males and females for age or body mass index. However, males had significantly higher glucose and triacylglycerol (triglyceride) levels, while the females had significantly higher HDL-C (high-density lipoprotein-cholesterol) and insulin sensitivity (13.00 ± 0.33 compared with 10.71 ± 0.31 mg·kg-1 of lean body mass·min-1, P<0.0001). Although peak EDD was significantly lower (6.28 ± 0.26 compared with 8.50 ± 0.28%, P<0.0001) in males than females, this difference was largely explained by adjustment for brachial artery diameter (P=0.15). Peak EID also was significantly lower in males than females (20.26 ± 0.44 compared with 28.64 ± 0.47%, P<0.0001), a difference that remained significantly lower after adjustment for brachial artery diameter. Males had a significantly greater cIMT compared with females (females 0.420 ± 0.004 compared with males 0.444 ± 0.004 mm, P=0.01), but when adjusted for carotid diameter, there was no significant difference (P=0.163). Although there were gender differences in vascular function and structure in the young adult population examined in this study, many of the differences were eliminated simply by adjusting for artery diameter. However, the lower EID observed in males could not be explained by artery diameter. Future studies need to continue to examine influence of gender on EID and other measures of vascular function.

Sex/gender medicine. The biological basis for personalized care in cardiovascular medicine

Sex differences in morbidity and mortality associated with cardiovascular disease have been recognized by the medical community for decades. Investigation into the underlying biological basis of these differences was largely neglected by the scientific community until a report released by the Institute of Medicine in the United States in 2001 "Exploring the Biological Contributions to Human Health: Does Sex Matter?" Recommendations from this report included the need for more accurate use of the terms "sex" and "gender", better tools and resources to study the biological basis of sex differences, integration of findings from different levels of biological organization and continued synergy between basic and clinical researchers. Ten years after the Institute's report, this review evaluates some of the sex differences in cardiovascular disease, reviews new approaches to study sex differences and emphasizes areas where further research is required. In the era of personalized medicine, the study of the biological basis of sex differences promises to optimize preventive, diagnostic and therapeutic strategies for cardiovascular disease in men and women, but will require diligence by the scientific and medical communities to remember that sex does matter.

The long-term effects of tibolone on aortic stiffness and endothelial function

OBJECTIVE

To investigate the effect of 10 years of treatment with tibolone on aortic stiffness and endothelial function.

DESIGN

Cross-sectional study of women currently participating in an open-label, non-randomized study of the long-term efficacy of tibolone. A total of 113 recently postmenopausal women were recruited in 1988. Fifty-eight agreed to take tibolone 2.5 mg daily and 55 were followed during the study as matched controls (who chose not to take any form of hormone replacement therapy (HRT) for the duration of the study). The groups were matched for age, weight and time since last menstrual period.

SETTING

A Central London Teaching Hospital.

SUBJECTS

After 10 years, 60 women remained in the study, 32 in the tibolone group and 28 in the control group. All of these women were invited to participate in this pilot study and attend the Menopause Research Unit. Fourteen women from each group agreed to attend. The main outcome measures were aortic stiffness, measured by pulse wave velocity, and endothelial function, as assessed by flow-mediated dilatation of the brachial artery.

RESULTS

Pulse wave velocity was significantly lower in the tibolone group (10.4 +/- 1.2) than in the control group (11.6 +/- 1.2), p = 0.042. The flow-mediated dilatations were similar in both groups.

CONCLUSION

In this study, long-term use of tibolone over 10 years has a beneficial effect on aortic stiffness. The differences seen in brachial artery vasoreactivity failed to reach statistical significance. Whether this is a true indication of the effects of long-term tibolone on brachial artery vasoreactivity will only be determined by performing a larger, placebo-controlled, randomized study.

Vascular actions of estrogens: functional implications

The impact of estrogen exposure in preventing or treating cardiovascular disease is controversial. But it is clear that estrogen has important effects on vascular physiology and pathophysiology, with potential therapeutic implications. Therefore, the goal of this review is to summarize, using an integrated approach, current knowledge of the vascular effects of estrogen, both in humans and in experimental animals. Aspects of estrogen synthesis and receptors, as well as general mechanisms of estrogenic action are reviewed with an emphasis on issues particularly relevant to the vascular system. Recent understanding of the impact of estrogen on mitochondrial function suggests that the longer lifespan of women compared with men may depend in part on the ability of estrogen to decrease production of reactive oxygen species in mitochondria. Mechanisms by which estrogen increases endothelial vasodilator function, promotes angiogenesis, and modulates autonomic function are summarized. Key aspects of the relevant pathophysiology of inflammation, atherosclerosis, stroke, migraine, and thrombosis are reviewed concerning current knowledge of estrogenic effects. A number of emerging concepts are addressed throughout. These include the importance of estrogenic formulation and route of administration and the impact of genetic polymorphisms, either in estrogen receptors or in enzymes responsible for estrogen metabolism, on responsiveness to hormone treatment. The importance of local metabolism of estrogenic precursors and the impact of timing for initiation of treatment and its duration are also considered. Although consensus opinions are emphasized, controversial views are presented to stimulate future research.

Review: Endothelial dysfunction: A potential tool in gender related cardiovascular disease

The overwhelming importance of distinctive cardiovascular disease profile in women has stimulated enormous efforts to disclose its cause. In this review, we discuss vascular endothelium as a potential phenotypic marker for the genetic difference. As it is a potentially modifiable factor for cardiovascular disease, every effort should be made to detect it, either directly or indirectly, at the earliest in females who are at risk, so that the future cardiovascular events might be prevented.

Isoflavones and endothelial function

Dietary isoflavones are thought to be cardioprotective due to their structural similarity to oestrogen. Oestrogen is believed to have beneficial effects on endothelial function and may be one of the mechanisms by which premenopausal women are protected against CVD. Decreased NO production and endothelial NO synthase activity, and increased endothelin-1 concentrations, impaired lipoprotein metabolism and increased circulating inflammatory factors result from oestrogen deficiency. Oestrogen acts by binding to oestrogen receptors α and β. Isoflavones have been shown to bind with greater affinity to the latter. Oestrogen replacement therapy is no longer thought to be a safe treatment for prevention of CVD; isoflavones are a possible alternative. Limited evidence from human intervention studies suggests that isoflavones may improve endothelial function, but the available data are not conclusive. Animal studies provide stronger support for a role of isoflavones in the vasculature, with increased vasodilation and endothelial NO synthase activity demonstrated. Cellular mechanisms underlying the effects of isoflavones on endothelial cell function are not yet clear. Possible oestrogen receptor-mediated pathways include modulation of gene transcription, and also non-genomic oestrogen receptor-mediated signalling pathways. Putative non-oestrogenic pathways include inhibition of reactive oxygen species production and up regulation of the protein kinase A pathway (increasing NO bioavailability). Further research is needed to unravel effects of isoflavones on intracellular regulation of the endothelial function. Moreover, there is an urgent need for adequately powered, robustly designed human intervention studies in order to clarify the present equivocal findings.

Effect of soy isoflavone protein and soy lecithin on endothelial function in healthy postmenopausal women

OBJECTIVE

To assess the effects of soy isoflavone protein concentrate and soy lecithin on endothelial function, measured as flow-mediated dilation (FMD) of the brachial artery in healthy postmenopausal women.

DESIGN

This was a randomized, double-blind, placebo-controlled crossover trial with 25 participants (mean age, 61 years; body mass index, 25.46 kg/m2). The women underwent endothelial function testing at baseline and after 4 weeks of randomly assigned treatment with intervening 4-week washout periods. Treatment assignments included soy isoflavone protein (25 g/day) and soy lecithin (20 g/day), soy isoflavone protein (25 g/day) and placebo lecithin, placebo protein and soy lecithin (20 g/day), and double placebo. FMD and serum lipid levels were assessed at baseline and the end of each 4-week treatment phase.

RESULTS

Twenty-two women completed the trial. No statistically significant (P > 0.05) difference was seen in FMD between treatment groups. A trend was suggested with FMD highest after treatment with soy protein plus lecithin (7.50 +/- 9.85), followed by soy protein (5.51 +/- 10.11), soy lecithin (5.35 +/- 6.13), and lowest after placebo (4.53 +/- 7.84). Soy isoflavone protein and soy lecithin significantly increased the high-density lipoprotein/low-density lipoprotein ratio (soy isoflavone protein plus soy lecithin, 0.64 +/- 0.19, P < 0.0001; soy isoflavone protein plus placebo lecithin, 0.58 +/- 0.17, P = 0.0058; placebo protein plus soy lecithin, 0.65 +/- 0.18, P < 0.0001) relative to the baseline value (0.49 +/- 0.15).

CONCLUSIONS

In this sample of healthy postmenopausal women, soy isoflavone protein and soy lecithin significantly improved the lipid profile. A favorable influence on endothelial function could not be confirmed.

A dose-response study of hormone replacement in young hypogonadal women: effects on intima media thickness and metabolism

OBJECTIVE

Young hypogonadal women appear to have an increased risk of cardiovascular disease. We studied the influence of increasing doses of hormone replacement therapy (HRT) on markers of metabolism and vascular physiology.

DESIGN

Nine-month sequential dose-ranging study.

PATIENTS

A total of 25 young hypogonadal women (Turner Syndrome, n = 14; 46,XX gonadal dysgenesis, n = 9), hypogonadotrophic hypogonadism (n = 2), mean age 31.9 years (range 18.5-42.2). All subjects sequentially received oral 17beta-oestradiol 1,2 and 4 mg daily in a cyclical formulation for 12 weeks each.

MEASUREMENTS

Metabolic markers and vascular physiology measurements to assess intima media thickness (IMT); arterial stiffness: pulse wave velocity (PWV) and augmentation index (AIx); endothelial function: flow-mediated dilatation (FMD). Results Increasing doses of oestrogen resulted in a reduction in IMT (0.63 +/- 0.06 vs. 0.58 +/- 0.06 vs. 0.56 +/- 0.06 mm at 1 mg, 2 mg and 4 mg 17beta-oestradiol, respectively, P = 0.001).

RESULTS

were similar in women with Turner Syndrome and normal karyotype. High-density lipoprotein (HDL) cholesterol concentrations increased (1.9 +/- 0.4 vs. 2.0 +/- 0.5 vs. 2.2 +/- 0.4 mmol/l, P = 0.001) and plasma glucose (4.8 +/- 0.4 vs. 4.7 +/- 0.3 vs. 4.6 +/- 0.6 mmol/l, P = 0.038) decreased slightly with the increasing dose of HRT. There was no correlation between the changes in IMT and HDL. Increasing HRT dose had no significant impact on blood pressure, weight, other lipid parameters, insulin, C-reactive protein, interleukin-6 and fibrinogen concentrations or FMD, PWV and AIx.

CONCLUSIONS

Increasing doses of HRT result in a reduction in carotid IMT in young hypogonadal women, along with increased serum HDL and decreased plasma glucose. This study raises the possibility that exogenous oestrogen may be cardioprotective in young women, but this observation needs to be balanced against a prothrombotic effect which is predominant in postmenopausal women.

Tibolone and estradiol plus norethisterone acetate similarly influence endothelium-dependent vasodilatation in healthy postmenopausal women

In healthy postmenopausal women, E(2) plus norethisterone acetate (1 mg + 0.5 mg) or tibolone (2.5 mg) similarly modify flow-mediated endothelium-dependent vasodilatation. The effect is dependent on baseline vasodilator reserve, with low values being augmented by either treatment.

Premature ovarian failure, endothelial dysfunction and estrogen-progestogen replacement

Cardiovascular disease, including coronary artery disease, stroke and peripheral vascular disease, is the leading cause of death among women. Vascular endothelial dysfunction is an early marker of atherosclerosis. Women with premature ovarian failure (or premature menopause) present an increased risk for cardiovascular disease, which might be attributed to the early onset of vascular endothelial dysfunction, associated with sex steroid deficiency. Cyclical estrogen and progestogen therapy has been shown to restore endothelial function in these young women. Further research is required to assess primarily the long-term effects of hormone replacement therapy on cardiovascular and overall prognosis in young women with premature ovarian failure, as well as the effects of different doses, duration and routes of hormone administration in these women.

Circadian variation in endothelial function is attenuated in postmenopausal women

OBJECTIVE

The present study was undertaken to investigate the possible existence of an endogenously generated circadian rhythm in endothelial function in women and whether this rhythm is altered after the menopause.

METHODS

Healthy non smoking women (11 pre-menopausal and 13 postmenopausal women) were studied during a 22 h period under constant routine conditions; endothelium-dependent (flow-mediated dilation (%FMD)) and -independent (glyceryl-trintrate (GTN)-mediated) function was assessed every 2 and 4 h, respectively, by high-resolution ultrasound of the brachial artery.

RESULTS

%FMD and %GTN was significantly higher in pre-menopausal women (9.9+/-1.0%FMD (mean+/-S.E.M.); 18.2+/-1.8%GTN; P<0.01) compared with postmenopausal women (6.5+/-0.5%FMD; 11.5+/-1.6%GTN). A significant day-night variation in %FMD was observed pre-menopausal women (day 9.2+/-0.8%; night 10.4+/-1%; P<0.05) with an attenuated rhythm in postmenopausal women (day 6.8+/-0.6%; night 6.0+/-0.4%).

CONCLUSIONS

The findings show a circadian rhythm in %FMD in pre-menopausal women, which disappears after the menopause. The reduction in %FMD and an absence of a day-night variation in %FMD in postmenopausal women may have important implications for the incidence of coronary heart disease in women after the menopause.

Endothelial function and its assessment

Endothelial dysfunction is a characteristic aspect of most of the conditions associated with atherosclerosis and is commonly found as an early feature in atherothrombotic vascular disease. An appreciation of the underlying mechanisms of endothelial function, as well as dysfunction, is essential as this has critical influence on the different methods in the assessment of endothelial function and effects of various treatments on its quantification. Furthermore, endothelial dysfunction is recognised as a type of 'target organ damage' in common cardiovascular conditions (e.g., hypertension) and the area is of increasing interest for new drug development, as therapies that modulate the endothelium will have added advantages; thus, for the development of new/experimental drugs, an awareness of ways to assess the endothelium is necessary. In this review, an overview of different methods including biochemical markers, and invasive and non-invasive tools, to determine endothelial function is presented as well as their clinical relevance. Furthermore, the effects of various treatments on endothelial dysfunction and their underlying mechanisms are elucidated.

Gender-based differences in brachial artery flow-mediated vasodilation as an indicator of significant coronary artery disease

Ultrasound of the brachial artery is widely used to assess endothelial function, but whether brachial artery flow-mediated vasodilation (FMD) differs between women and men who have coronary artery disease (CAD) has not been examined. To investigate gender-based differences in brachial artery FMD as an indicator of significant CAD, FMD was measured in women and men outpatients who had CAD (coronary stenosis >50%, n = 64) and those who did not have significant CAD (n = 145). FMD in women who had CAD (n = 33, 9.1 +/- 0.8%) was higher than that in similarly aged men who had CAD (n = 31, 6.4 +/- 0.5%; p = 0.008). The FMD cutpoint that maximized sensitivity with least effect on specificity for screening CAD was 15% (91% sensitivity, 25% specificity) in women but 10% (90% sensitivity, 43% specificity) in men. If the cutpoint as defined in men were used to evaluate women, brachial artery ultrasound would fail to diagnose 42% of women who do not have significant CAD; thus, a higher FMD cutpoint is required to optimize the sensitivity of FMD for identifying women who have significant CAD compared with similarly aged men. In studies using FMD to evaluate cardiovascular risk, different standards should be applied for women and men.

Peripheral vascular endothelial function correlates with exercise capacity in women

BACKGROUND

Vascular endothelial function has been observed to correlate with exercise capacity in predominantly male populations. Gender-based differences exist in the clinical course of coronary artery disease, and previous studies indicate that estrogen may influence endothelial function. These observations raise the possibility that the relationship between endothelial function and exercise capacity in women may differ from that in men.

HYPOTHESIS

This study aimed to determine whether peripheral vascular endothelial function correlates with exercise capacity in women.

METHODS

Women who were referred for clinically indicated exercise testing with technetium-99 myocardial perfusion imaging were consecutively recruited. To ensure a population free of exercise limitation due to ischemic heart disease, women without myocardial perfusion defects were included for analysis in this study (n = 105). Endothelial function was assessed by brachial artery ultrasound flow-mediated vasodilation (FMD). Exercise capacity was defined as the duration of exercise on a symptom-limited Bruce protocol.

RESULTS

Mean FMD was 11.8 +/- 0.6%, and median FMD was 12%. Subjects with an FMD less than the median of 12% had a significantly shorter exercise time than those with FMD > or = 12% (411 +/- 17 vs. 482 +/- 24 s, p = 0.014). There was a significant correlation between FMD and exercise time (r = 0.34, p < 0.001). Age and body mass index were additional predictors of exercise time; however, the relationship between FMD and exercise time was independent of these variables.

CONCLUSION

Brachial artery FMD correlates with exercise capacity in women, even in the absence of ischemic heart disease.

Influence of hormone therapy on the cardiovascular responses to stress of postmenopausal women

Epidemiological and psychophysiological data suggest that groups that differ in reproductive hormones and stress responses also differ in risk for cardiovascular disease. To evaluate the effects of hormone therapy on women's cardiovascular responses to laboratory stressors, 89 healthy postmenopausal women were tested twice, before and after exposure for about 8 weeks to one of the five conditions: placebo, Estratab (primarily estrone), Estratab plus Prometrium (micronized progesterone), Estratab plus Provera (synthetic progestin), and Estratest (same estrogen as in Estratab plus methyltestosterone). Results showed that women assigned to Estratab plus Prometrium and Estratest had diminished systolic blood pressure responses to stress upon retesting, whereas the other groups did not change in the level of their responses. Women assigned to Estratab plus Prometrium had diminished diastolic blood pressure responses during a speech stressor upon retesting, whereas women assigned to Estratab plus Provera increased. Our findings show that hormone therapy does affect women's stress responses, but they do not provide a simple explanation as to why groups at high and low risk for cardiovascular disease differ in reproductive hormones and stress responses.

Effect of long-term hormone replacement therapy on coronary endothelial function in postmenopausal women

OBJECTIVES

To determine the difference in endothelial function between premenopausal and postmenopausal women and to determine whether hormone replacement therapy (HRT) is associated with an improvement in coronary endothelial function.

PATIENTS AND METHODS

Women undergoing coronary physiology studies for chest pain at the Mayo Clinic In Rochester, Minn, between December 1992 and April 2002 underwent assessment of coronary endothelium-independent and -dependent function with intracoronary administration of adenosine and acetylcholine, respectively. The coronary diameters, coronary blood flows, and coronary velocity reserves were measured.

RESULTS

A total of 270 women (89 premenopausal and 181 postmenopausal) participated in the study. Endothelium-dependent coronary blood flow change (baseline to peak flow) in response to acetylcholine (10(-4), 10(-5), and 10(-4) mol/L) was lower in postmenopausal women compared with premenopausal women (39.7% vs 72.9%, P = .03). There was no significant difference between the postmenopausal women receiving and not receiving HRT with regard to percent change in coronary diameter (-21.8% vs -13.9%, P = .15), percent change in coronary blood flow (37.3% vs 42.7%, P = .74), or coronary velocity reserve (2.7 vs 2.7, P = .82).

CONCLUSION

This study shows that the postmenopausal state is associated with a greater abnormality in coronary endothelial function at the level of the microcirculation. Moreover, HRT status was not associated with an improvement in coronary endothelial function in postmenopausal women.

Interactions between autonomic nervous system activity and endothelial function: a model for the development of cardiovascular disease

OBJECTIVES

Endothelial dysfunction is a new pathway in cardiovascular disease (CVD) development. Psychosocial factors have been little studied in relation to endothelial function, although they may interact via associations with the autonomic nervous system (ANS). The purpose of this review is to propose a model by which psychosocial factors are related to CVD development through interactions between the ANS and vascular endothelium.

METHODS

The literature supporting an interaction between the ANS and endothelium in healthy and disease states is reviewed. Potential mechanisms linking the two systems are explored as a pathway for CVD development.

RESULTS

Endothelial dysfunction and impaired cardiovascular ANS regulation are both markers for increased CVD risk. Sympathetic nerves and vascular endothelial cells share a functional antagonism in healthy states to maintain appropriate blood vessel tone. Alterations in sympathetic activity and endothelial cell function are both observed early in the development of CVD and may result from an inability to maintain the functional antagonism. Impairments in either ANS regulation or endothelial function may contribute to further disease development by evoking maladaptive changes in the opposing system.

CONCLUSIONS

Although interactions between cardiovascular ANS regulation and endothelial function are likely involved in CVD development, further research is needed to determine whether ANS and endothelium interactions are a plausible pathway linking psychosocial factors with increased CVD risk.

The short-term effects of different regimens of hormone replacement therapy on left ventricular structure and performance in healthy postmenopausal women. A prospective, controlled echocardiographic study

OBJECTIVE

To compare the short-term effects of different hormone replacement therapy (HRT) regimens on left ventricular structure and function in healthy postmenopausal women.

METHODS

Forty-two apparently healthy postmenopausal women were evaluated prospectively in this controlled study. Subjects were divided into 4 groups. Ten subjects, who did not accept HRT or any other treatments, formed the control group. The remaining subjects were assigned to receive oral estradiol (2 mg/day) + norethisterone acetate (1 mg/day) (n = 11), transdermal estradiol (0.05 mg) + norethisterone acetate (0.25 mg) (n = 11) or tibolone (2.5 mg/day) (n = 10) therapy during 12 weeks. Echocardiography and Doppler techniques were used to assess the cardiac effects of different HRT regimens.

RESULTS

After 12 weeks of treatment, there were significant increases in left ventricular ejection fraction (transdermal group: p = 0.008, oral group: p = 0.003, tibolone group: p = 0.005) and cardiac output (transdermal group: p = 0.003, oral group: p = 0.003, tibolone group: p = 0.021) in all treatment groups. In addition, in the transdermal group, a slight increase in left ventricular end-diastolic volume was significant (p = 0.046).

CONCLUSION

These data suggest that oral and transdermal HRT regimens and tibolone may contribute to the improvement in left ventricular systolic function without having an effect on left ventricular structure after short-term administration in healthy postmenopausal women.

Raloxifene, conjugated oestrogen and endothelial function in postmenopausal women

OBJECTIVES

To study the long-term effects of raloxifene, a potential designer oestrogen, and oestrogen monotherapy on endothelial function in healthy postmenopausal women.

DESIGN

A 2-year double-blind, randomized and placebo-controlled study in an Academic Medical Center. Fifty-six hysterectomized but otherwise healthy postmenopausal women randomly received raloxifene hydrochloride 60 mg day-1 (n = 15) or 150 mg day-1 (n = 13), conjugated equine oestrogen (CEE) 0.625 mg day-1 (n = 15), or placebo (n = 13).

MAIN OUTCOME MEASURES

Endothelial function as estimated from brachial artery flow-mediated, endothelium-dependent vasodilation and nitroglycerine-induced endothelium-independent vasodilation, and plasma levels of the endothelium-derived regulatory proteins, von Willebrand factor (vWF) and endothelin (ET).

RESULTS

Raloxifene 60 mg did not significantly affect endothelial function. As compared with placebo, at 6 months of therapy, raloxifene 150 mg and CEE were associated with a mean increase in vWF of 25.5% point (95% CI 3.6-47.3) and 26.6% point (95% CI 6.9-46.3), respectively. At 24 months of therapy, raloxifene 150 mg was associated with a mean decrease in ET of 0.96 pg mL-1 (95% CI -1.57 to -0.36). Raloxifene nor CEE significantly affected endothelium-dependent and/or -independent vasodilation.

CONCLUSIONS

Our results suggest that long-term therapy with raloxifene or oral CEE does not affect endothelium-dependent vasodilation in healthy postmenopausal women. Raloxifene 150 mg day-1 might have both positive and negative effects on endothelium. The clinical significance of these findings remains to be investigated.

Lipid profiles and endothelial function with low-dose hormone replacement therapy in postmenopausal women at risk for coronary artery disease: a randomized trial

AIMS

To compare the effect of low (0.3 mg) and commonly prescribed (0.625 mg) doses of conjugated equine estrogens (CEE) on brachial artery flow-mediated dilation and lipid profiles.

METHODS AND RESULTS

Twenty-five postmenopausal women (mean age, 65+/-6 years) at risk for coronary artery disease (CAD) (> or =2 established risk factors) entered a double-blind crossover study. Brachial artery endothelial function was evaluated by means of high-resolution vascular echography. Both CEE doses significantly decreased total cholesterol (-13%, 0.3 mg; -15%, 0.625 mg), low-density lipoprotein-cholesterol (LDL-C) (-15%, 0.3 mg; -16%, 0.625 mg), and lipoprotein(a) (-28%, 0.3 mg; -39%, 0.625 mg) values from baseline levels. Both treatments increased high-density lipoprotein-cholesterol (HDL-C) (5%, 0.3 mg; 7%, 0.625 mg) and triglycerides (3%, 0.3 mg; 8%, 0.625 mg). There was no dose effect for changes in the LDL-C/HDL-C ratio (-21%, 0.3 mg; -23%, 0.625 mg). Both doses improved brachial artery dilation during reactive hyperemia by 63% over baseline.

CONCLUSION

In women at risk for CAD, low-dose hormone replacement treatment (HRT) improves lipid profiles and brachial artery endothelial function comparably to the most commonly prescribed dose. The benefit:risk ratio of low-dose HRT provides an attractive option for postmenopausal women at risk for CAD.

Associations between psychological traits and endothelial function in postmenopausal women

OBJECTIVE

The objective of this study was to determine whether psychosocial risk factors for cardiovascular disease (CVD) are associated with impairments in endothelial function and to determine whether use of hormone replacement therapy (HRT) can moderate observed associations among women without prior CVD.

METHODS

Flow-mediated dilation was assessed by brachial ultrasound after reactive hyperemia in 193 postmenopausal women enrolled in the prospective Healthy Women Study. Measures of psychosocial characteristics had been completed at study entry, when the women were premenopausal (mean = 13.6 years earlier), and at a separate postmenopausal follow-up exam near the time of the ultrasound (mean = 1.5 years earlier).

RESULTS

Factor analyses of the psychosocial characteristics yielded two factors: Type A/anger and anxiety/depression. Anxiety/depression scores at the study entry and follow-up exams and Type A/anger scores at the study entry exam were associated with less vasodilation (p values < 0.05). Type A/anger scores at the follow-up exam were associated with less vasodilation among women not using HRT (p <.05).

CONCLUSIONS

Psychosocial risk factors for CVD are associated with impaired brachial artery dilation among postmenopausal women. HRT use may mask some associations between psychosocial risk factors and endothelial dysfunction among postmenopausal women.

Orally and transdermally replaced estradiol improves endothelial function equally in middle-aged women after surgical menopause

OBJECTIVE

Improvement in endothelial function may be an important mechanism by which estrogen replacement therapy protects postmenopausal women against coronary artery disease. We determined whether the vascular effects of estradiol depend on the route of administration.

STUDY DESIGN

Six weeks after surgically induced menopause, 43 healthy women were assigned randomly to 28 weeks of treatment by either orally or transdermally replaced estradiol. Endothelium-dependent and endothelium-independent dilation were calculated with the use of the diameters of the brachial artery that were measured at rest by high resolution ultrasound scanning after reactive hyperemia and after sublingual glyceryl trinitrate.

RESULTS

Endothelium-dependent dilation increased after oral estradiol replacement from 6% +/- 3.9% to 13.2% +/- 4.4% (P <.0001) and after transdermal estradiol replacement from 7% +/- 4.9% to 14.9% +/- 5.6%(P <.0001). Endothelium-independent dilation did not change significantly in either group. The improvements in endothelium-dependent dilation after estrogen substitution were independent of the changes in blood lipids and lipoproteins.

CONCLUSION

Both oral and transdermal long-term replacement of estradiol lead to improved endothelial function in healthy middle-aged women after surgically induced menopause.

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.

Impaired cardiac response to exercise in post-menopausal women: relationship with peripheral vascular function

Endothelial dysfunction has been demonstrated in post-menopausal women. To assess the relationship between peripheral vascular reserve and cardiac function during exercise in post-menopausal women, 91 subjects, who had no ischaemic findings on myocardial SPECT, were assigned to four groups: pre-menopausal women (n=13), post-menopausal women (n=33), younger men aged < or =50 years (n=10), and older men aged >50 years (n=35). First-pass radionuclide angiography was performed before and during bicycle exercise to calculate ejection fraction (EF) and peripheral vascular resistance (VR). There were no differences in haemodynamic variables among the groups at baseline. The per cent increase in EF=(exercise EF - resting EF)x100/resting EF, and the per cent decrease in VR=(resting VR - exercise VR)x100/resting VR were depressed in the post-menopausal women (0.4+/-2% and 35+/-3%, respectively) compared to the pre-menopausal women (10+/-3% and 47+/-3%, respectively; P<0.05 each). Although the age dependent impairment is thought to cause this depression, neither the per cent increase in EF nor the per cent decrease in VR in the older men was significantly different from that in the younger men. Post-menopausal women exhibited depressed cardiac function during exercise, which may be related to the impairment of peripheral vascular function after menopause.

Raloxifene does not influence flow-mediated endothelium-dependent and endothelium-independent vasodilatation of osteopenic postmenopausal women

OBJECTIVE

The study was undertaken to evaluate whether raloxifene influences endothelium-dependent and endothelium-independent vasodilatation in women.

STUDY DESIGN

In a double-blind, placebo-controlled randomized study, 30 osteopenic but otherwise healthy postmenopausal women received either placebo (n = 15 with one dropout) or raloxifene (60 mg/d, n = 15). Brachial artery flow-mediated endothelium-dependent and endothelium-independent vasodilatation was evaluated by ultrasound before and after 6 months of treatment, along with lipid and glucose metabolism. Endothelium-dependent dilatation was evaluated after a 4-minute block of artery blood flow through a cuff insufflated at suprasystolic blood pressure. Endothelium-independent vasodilatation was evaluated after sublingual nitroglycerin administration (400 microg).

RESULTS

Placebo did not modify any vascular or metabolic parameter. Raloxifene significantly decreased low-density lipoprotein levels (4.60 +/- 0.18 mmol/L vs 3.94 +/- 0.30 mmol/L, P <.015) but did not modify endothelium-dependent (21.6% +/- 4.6% vs 20.6% +/- 3.8%) or endothelium-independent vasodilatation (26.3% +/- 5.1% vs 32.0% +/- 5.5%).

CONCLUSION

Prolonged administration of raloxifene does not influence endothelium-dependent and endothelium-independent vasodilatation of osteopenic but otherwise healthy postmenopausal women.

Estrogen effect on heart rate variability in hypertensive postmenopausal women

Healthy postmenopausal women and hypertensive patients show an imbalance in the modulation of autonomic nervous control of the cardiovascular system, which may increase the cardiovascular risk.

OBJECTIVE

To examine the heart rate variability (HRV) response to estrogen replacement therapy (ERT) and its association with changes in metabolic variables in hypertensive postmenopausal women.

METHODS

A double-blind, placebo-controlled clinical trial was conducted in 30 hypertensive postmenopausal women receiving 180 mg/day of verapamil. The experimental group (n=16) received 0.625 mg OD of natural conjugated estrogens during 4 months, while control group (n=14) received a placebo. Lipids, lipoproteins, apolipoproteins, glucose and insulin were measured at 0, 2 and 4 months. HRV was determined in time and frequency domains using a 24-h Holter before and after ERT.

RESULTS

Significant higher values of spectral and non-spectral parameters of HRV, associated with a lower LF/HF ratio, were found at the end of 4 months of ERT. Multiple regression analysis revealed that estrogen treatment itself and changes in total cholesterol, LDL-cholesterol, glucose and waist circumference, contributed to the changes observed in indexes reflecting parasympathetic activity in time and frequency domains.

CONCLUSIONS

We conclude that ERT partially improves HRV favoring increased parasympathetic drive, and that part of the effect may be mediated by changes in metabolic variables.

Women's angiographic vitamin and estrogen trial: design and methods

The Women's Angiographic Vitamin and Estrogen trial was a randomized, double-blind, placebo-controlled study designed to test the efficacy of estrogen replacement and antioxidant vitamins for preventing angiographic progression of coronary artery disease. Postmenopausal women with one or more angiographically documented coronary stenoses of 15-75% at baseline were assigned in a 2 x 2 factorial randomization to active hormone replacement therapy (conjugated estrogens for women who had had a hysterectomy or conjugated estrogens with medroxyprogesterone for women with intact uteri) or placebo and to active vitamins E and C or their placebos. Seven clinical centers, five in the United States and two in Canada, randomized 423 women between July 1997 and July 1999. Quantitative coronary angiography was performed at baseline and repeated after projected mean follow-up of 3 years.

Inflammation and outcome in end-stage renal failure: does female gender constitute a survival advantage?

BACKGROUND

Elevated C-reactive protein (CRP) is a strong predictor of cardiovascular events and all-cause mortality in end-stage renal disease (ESRD) patients. However, although sex hormones may influence serum levels of inflammatory proteins, gender has not been taken into consideration in previous studies of inflammation and outcome in ESRD patients.

METHODS

We included 663 (374 males) ESRD patients (59 +/- 1 year) from three European renal centers (Sweden, Germany and Italy) in which CRP levels and outcome data (follow-up 33 +/- 1 months) were available. The relation between outcome and serum levels of the soluble intercellular adhesion molecule (sICAM-1) was evaluated in 312 of the patients.

RESULTS

The present study shows that elevated CRP is a strong predictor of outcome, but whereas no difference in all-cause mortality was observed between non-inflamed (CRP <or=3.4 mg/L) males and females, inflamed males had a significantly (log rank 6.1; P = 0.01) higher mortality rate than inflamed females. A strong positive correlation between CRP and sICAM-1 was found in the combined patient material (rho = 0.37; P < 0.0001) as well as in the male (rho = 0.25; P < 0.01) and female (rho = 0.52; P < 0.0001) subgroups. The Cox proportional hazard model showed that whereas both elevated sICAM-1 and log CRP predicted outcome in males, neither predicted outcome significantly in females.

CONCLUSIONS

As inflamed female patients have a better outcome that inflamed males the present observation suggests that sex hormones may have important cardioprotective effects that limit the effect of inflammation on vascular injury in female ESRD patients.