Postmenopausal oestrogen replacement therapy and atherosclerosis: can current compounds provide cardiovascular protection?

Clinical usefulness of metabolic risk factors to identify young asymptomatic women adults with subclinical atherosclerosis: A cross-sectional study

Interventions of cardiovascular disease should be implemented in early ages. But most studies were performed in middle aged or elderly adults because of the low prevalence in young, especially for women. We investigate the association between metabolic risk factors and subclinical atherosclerosis in young asymptomatic women adults, using carotid intima-media thickness (CIMT) as a marker of the atherosclerotic process.We performed a cross-sectional study of 950 Chinese young asymptomatic women adults (37.28 ± 5.16 years) who underwent a routine health screening examination. Triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), total cholesterol (TC), fasting blood glucose (FBG), homocysteine (HCY), gamma glutamyltransferase (GGT), uric acid, and CIMT were measured.Out of 950 subjects, 16 (1.7%) were detected with increased CIMT. Significant differences existed in the indicators including age, body mass index (BMI), TC, TG, LDL-C, LDL-C/HDL-C, non-HDL-C, and TC/HDL-C. Although TG, LDL-C, non-HDL-C, TC/HDL-C, and TG/HDL-C were the significant indicators when adjusted for age only, age, LDL-C/HDL-C, FBG, and GGT were the only independent relative indicators of increased CMIT that entered the multivariate model. The area under receiver operating characteristic curve for a linear combination of age, LDL-C/HDL-C, FBG, and GGT was 0.809 (95% confidence interval = 0.712-0.906), superior to any of the variables taken alone (age, AUC = 0.707; FBG, AUC = 0.710; LDL-C/HDL-C, AUC = 0.695; GGT, AUC = 0.648).The combined assessment of age, LDL-C/HDL-C, FBG, and GGT contributes to an early detection for subclinical atherosclerosis, providing guidance to clinicians for women's early interventions of latent cardiovascular disease. Neither of the above four individual indicators is qualified alone.

Estrogens and Coronary Artery Disease: New Clinical Perspectives

In premenopausal women, endogenous estrogens are associated with reduced prevalence of arterial hypertension, coronary artery disease, myocardial infarction, and stroke. Clinical trials conducted in the 1990s such as HERS, WHI, and WISDOM have shown that postmenopausal treatment with horse hormone mixtures (so-called conjugated equine estrogens) and synthetic progestins adversely affects female cardiovascular health. Our understanding of rapid (nongenomic) and chronic (genomic) estrogen signaling has since advanced considerably, including identification of a new G protein-coupled estrogen receptor (GPER), which like the "classical" receptors ERα and ERβ is highly abundant in the cardiovascular system. Here, we discuss the role of estrogen receptors in the pathogenesis of coronary artery disease and review natural and synthetic ligands of estrogen receptors as well as their effects in physiology, on cardiovascular risk factors, and atherosclerotic vascular disease. Data from preclinical and clinical studies using nonselective compounds activating GPER, which include selective estrogen receptor modulators such as tamoxifen or raloxifene, selective estrogen receptor downregulators such as Faslodex™ (fulvestrant/ICI 182,780), vitamin B3 (niacin), green tea catechins, and soy flavonoids such as genistein or resveratrol, strongly suggest that activation of GPER may afford therapeutic benefit for primary and secondary prevention in patients with or at risk for coronary artery disease. Evidence from preclinical studies suggest similar efficacy profiles for selective small molecule GPER agonists such as G-1 which are devoid of uterotrophic activity. Further clinical research in this area is warranted to provide opportunities for future cardiovascular drug development.

The value of the apoB/apoAΙ ratio and the non-HDL-C/HDL-C ratio in predicting carotid atherosclerosis among Chinese individuals with metabolic syndrome: a cross-sectional study

BACKGROUND

Metabolic syndrome (MetS) is associated with carotid intima-media thickness (CIMT), which is a good predictor of cardiovascular disease (CVD). However, among individuals with MetS, direct comparative data regarding the utility of the apoB/apoAΙ ratio and the non-HDL-C/HDL-C ratio to diagnose carotid atherosclerosis are scarce, particularly in Chinese populations. We aimed to determine the relationship between the apoB/apoAΙ ratio and the non-HDL-C/HDL-C ratio and carotid atherosclerosis among Chinese individuals with MetS.

METHODS

We performed a retrospective study of 5822 Chinese participants who underwent a routine health screening examination. Lipid profiles, fasting glucose, fasting insulin, CRP, apoB, apoAΙ and CIMT were measured.

RESULTS

We observed that among Chinese individuals with MetS, men (53.95±0.58 ys) developed carotid atherosclerosis at a younger age than women (58.47±1.17 ys) (P<0.001). Both the apoB/apoAΙ ratio and the non-HDL-C/HDL-C ratio positively correlated with carotid atherosclerosis among Chinese individuals with MetS, particularly among women. Meanwhile, CIMT increased progressively across the quartiles of the non-HDL-C/HDL-C ratio (P for trend, <0.05). Receiver Operating Characteristic (ROC) analysis indicated that the AUC of the apoB/apoAΙ ratio (0.561) was higher than that of the non-HDL-C/HDL-C ratio (0.522) in men (P<0.05) and the AUC of the apoB/apoAΙ ratio (0.640) was lower than that of the non-HDL-C/HDL-C ratio (0.695) in women (P<0.05). Among Chinese individuals with MetS, the AUC of the non-HDL-C/HDL-C ratio was more prominent among women compared with men (P<0.05).

CONCLUSION

Our findings indicate that among individuals with MetS, Chinese men develop carotid atherosclerosis at a much younger age than women. There were no significant differences between the apoB/apoAΙ ratio and the non-HDL-C/HDL-C ratio for the prediction of carotid atherosclerosis among Chinese individuals with MetS. Among Chinese individuals with MetS, the utility of the non-HDL-C/HDL-C ratio was found to be greater among women than among men.

Non-genomic regulation of vascular cell function and growth by estrogen

Estrogens exert rapid, non-genomic effects, which are mediated by plasma membrane-associated estrogen receptors (mER) mERalpha and mERbeta, and the intracellular transmembrane G protein-coupled estrogen receptor (GPER). Membrane-initiated responses contribute to transcriptional activation, resulting in a complex interplay of nuclear and extra-nuclear mechanisms that mediate the acute physiological responses to estrogens. Non-genomic estrogen signaling also activates a variety of intracellular estrogen signaling pathways that regulate vascular function and cell growth involving rapid but also long-term effects. This review discusses recent advances in understanding of the mechanisms of non-genomic estrogen receptor signaling in the vascular wall.

Need for research on estrogen receptor function: importance for postmenopausal hormone therapy and atherosclerosis

BACKGROUND

Cardiovascular disease is the leading cause of morbidity and mortality in men and women worldwide. Although rare in premenopausal women, its incidence rises sharply after menopause, indicating atheroprotective effects of endogenous estrogens.

OBJECTIVE

This review discusses the differential effects of estrogen receptor function on atherosclerosis progression in pre- and postmenopausal women, including aspects of gender differences in vascular physiology of estrogens and androgens.

METHODS

Recent advances in the understanding of the pathogenesis of atherosclerosis, estrogen receptor function, and hormone therapy are reviewed, with particular emphasis on clinical and molecular issues.

RESULTS

Whether hormone therapy can improve cardiovascular health in postmenopausal women remains controversial. Current evidence suggests that the vascular effects of estrogen are affected by the stage of reproductive life, the time since menopause, and the extent of subclinical atherosclerosis. The mechanisms of vascular responsiveness to sex steroids during different stages of atherosclerosis development remain poorly understood in women and men.

CONCLUSION

In view of the expected increase in the prevalence of atherosclerotic vascular disease worldwide due to population aging, research is needed to determine the vascular mechanism of endogenous and exogenous sex steroids in patients with atherosclerosis. Such research may help to define new strategies to improve cardiovascular health in women and possibly also in men.

Obesity-associated activation of angiotensin and endothelin in the cardiovascular system

The renin-angiotensin system (RAS) and the endothelin system have been implicated in the pathogenesis of human cardiovascular and renal diseases, and inhibition of the RAS markedly improves morbidity and survival. Obesity in humans is associated with an increased risk for the development of hypertension, atherosclerosis and focal-segmental glomerulosclerosis, however the exact mechanisms underlying these pathologies in obese individuals are not known. This article discusses the clinical importance of obesity and the current evidence for local activation of the renin-angiotensin system and its interactions with the endothelin system in obesity and the cardiovascular pathologies associated with it.