Estrogènes endogènes et risque cardiovasculaire chez les femmes ménopausées

The low incidence of coronary heart disease among women has often been attributed to sex hormones. However, adverse effects of estrogens on arterial disease have been recently reported in older postmenopausal women. In the French Three-City prospective cohort study of subjects over 65 years of age, I investigated the association of endogenous estradiol with cardiovascular risk among postmenopausal women who did not use any hormone therapy. In a first part, I showed that high levels of plasma estradiol were related to the 4-year incidence of ischemic arterial disease (IAD), independently of traditional cardiovascular risk factors such as obesity or diabetes. Then, I reported that the relation between estrogens and IAD risk could be modulated by estrogen receptor-α (ESR1) polymorphisms. Indeed, endogenous estrogens were positively associated with IAD risk in women carrying the ESR1 rs9340799-AA genotype but not in those carrying the ESR1 rs9340799-AG/GG genotype. Further analyses revealed that both hypercoagulability and inflammatory state might act as mediators. Finally, I assessed the long-term predictor role of endogenous estrogens in arterial disease. I showed a positive and independent association of estrogens levels with the 10-year incidence of cardiovascular disease. Overall, high plasma levels of endogenous estradiol emerge as a new significant predictor of cardiovascular disease in older postmenopausal women. If confirmed, these findings could have the potential to improve the stratification of IAD risk in postmenopausal women.La relative immunité des femmes vis-à-vis du risque cardiovasculaire a longtemps été attribuée aux hormones sexuelles. Néanmoins, le rôle protecteur des estrogènes dans le développement de l’athérosclérose et de ses complications a été récemment remis en cause chez les femmes ménopausées. A partir de la cohorte française des Trois Cités incluant environ 10.000 sujets de plus de 65 ans, j’ai évalué l’association entre les estrogènes endogènes et le risque de maladies cardiovasculaires chez des femmes n’utilisant pas de traitement hormonal. J’ai montré pour la première fois que des taux élevés d’estradiol plasmatique étaient associés à une augmentation du risque artériel ischémique à 4 ans, indépendamment des facteurs de risque cardiovasculaire traditionnels, notamment l’obésité ou le diabète. Dans une deuxième partie, j’ai étudié le rôle modulateur des polymorphismes génétiques des récepteurs des estrogènes α (ESR1) et β (ESR2). J’ai montré que le risque cardiovasculaire augmentait avec les taux élevés d’estradiol chez les femmes porteuses du génotype rs9340799-AA mais pas chez celles avec le génotype rs9340799-AG/GG. Des analyses complémentaires m’ont également permis de suggérer que l’effet des estrogènes était lié en partie à une hypercoagulabilité et un état inflammatoire. Dans une dernière étape, j’ai évalué le rôle prédicteur à long terme des estrogènes endogènes. J’ai confirmé la relation indépendante entre les taux élevés d’estrogènes et la survenue d’un évènement cardiovasculaire après 10 ans de suivi. Globalement, ces résultats suggèrent un effet délétère des estrogènes dans le développement des maladies artérielles ischémiques chez les femmes ménopausées après 65 ans . Si ces résultats étaient confirmés, une meilleure stratification du risque artériel pourrait être proposée chez les femmes ménopausées avec des implications potentielles dans la prévention des maladies cardiovasculaires

Testostérone plasmatique et risque cardiovasculaire chez les hommes après 65 ans

Le déclin des hormones sexuelles avec l'âge a été mis en cause dans le développement de nombreuses maladies. Chez les hommes, la baisse de la testostérone circulante est un prédicteur de la mortalité toutes causes mais son impact sur le risque cardiovasculaire est incertain. A partir de l étude de cohorte des Trois Cités (3C), réalisée en France dans la population générale, j'ai étudié le rôle de la testostérone plasmatique dans la survenue des évènements artériels ischémiques chez les hommes de plus de 65 ans.J'ai montré, dans une première partie, que des taux diminués de testostérone étaient associés à des facteurs de risque cardiovasculaire. J'ai notamment confirmé le rôle central de la masse grasse et du diabète comme déterminants des androgènes. De plus, j'ai mis en évidence une association inverse entre la testostérone et l épaisseur intima-media (EIM) des artères carotidiennes. J'ai montré que cette relation dépendait du statut inflammatoire systémique avec des variations significatives de l'EIM observées uniquement chez les hommes ayant des niveaux élevés de protéine C-réactive. En revanche, aucune association significative n'a pu être détectée entre les androgènes et la présence de plaques d'athérome.Dans une seconde partie, j'ai mis en évidence une relation originale en forme de J entre la testostérone et le risque de maladies artérielles ischémiques. Les hommes ayant des taux élevés ou diminués de testostérone présentaient un risque accru d évènements artériels et cette relation ne dépendait pas des principaux facteurs de risque cardiovasculaire. Des résultats similaires étaient observés pour les cardiopathies ischémiques et les accidents vasculaires cérébraux ischémiques.Ces résultats suggèrent que des taux moyens de testostérone totale circulante (4-5 ng/mL) protègent des maladies artérielles ischémiques. Ce rôle modulateur des androgènes pourrait être lié à un processus de vieillissement précoce non spécifique.The age-related decline in sex hormones has been involved in the development of many diseases. In men, low endogenous testosterone levels predict mortality due to all causes. However, the role of testosterone in the development of cardiovascular disease remains uncertain. In the french Three-City population-based cohort study, I assessed the association of plasma sex hormones with the incidence of ischemic arterial disease in men aged over 65 years.First, I showed that low testosterone levels were associated with cardiovascular risk factors. I confirmed a leading role of obesity and diabetes as determinants of androgens. I also found an inverse association between testosterone and carotid intima-media thickness (IMT). I highlighted that, this relationship was mediated through systemic inflammation as significant changes in IMT were observed only in men with high C-reactive protein levels. However, no significant association was detected between androgens and the presence of carotid plaques.Second, I found an original J-shaped association between testosterone and risk of ischemic arterial disease. Men with elevated or decreased testosterone levels had higher risk of arterial events and this association was independent of major cardiovascular risk factors. Similar results were observed for ischemic heart disease and ischemic stroke.Overall, these results suggest that intermediate testosterone levels (4-5 ng/mL) could protect against cardiovascular events. Androgens could also be involved in general ageing process.PARIS11-SCD-Bib. électronique (914719901) / SudocSudocFranceF

A U-shaped relationship between haematocrit and mortality in a large prospective cohort study

Background: Only a limited number of studies have investigated the correlation between haematocrit (HCT) and mortality in the general population, and few of those studies have had data on a wide range of low and high levels of HCT. We investigated the association between baseline HCT and mortality in a prospective cohort study of 49 983 adult subjects in Iran with a broad spectrum of HCT values. Methods: Data on socio-demographic and life-style factors, past medical history, and levels of HCT were collected at enrollment. During a mean follow-up of 5 years (follow-up success rate ±99%), 2262 deaths were reported. Cox proportional hazards regression models were used to estimate hazard ratios and corresponding 95% confidence intervals. Results: There was a U-shaped relationship between categories of HCT and mortality in both sexes: both low and high levels of HCT were associated with increased overall mortality and mortality from cardiovascular disease. The U-shaped relationship persisted after several sensitivity analyses were done, including analyses restricted to non-smokers and non-users of opium; analyses excluding deaths from accidents and other external causes as well as deaths of persons with self-reported ischemic heart disease at the baseline interview for the study; and analyses excluding the first 2 years of follow-up. Self-reported past medical history and lack of data about lipids and other cellular blood components were the major limitations of the study. Conclusions: Low and high levels of HCT are associated with increased mortality in the general population. The findings in the present study can be of particular importance for low- and middle-income countries in which a substantial proportion of the population lives with suboptimal levels of HCT. © Published by Oxford University Press on behalf of the International Epidemiological Association 2013

Using Basic Science to Design a Clinical Trial: Baseline Characteristics of Women Enrolled in the Kronos Early Estrogen Prevention Study (KEEPS)

Observational and epidemiological studies suggest that menopausal hormone therapy (MHT) reduces cardiovascular disease (CVD) risk. However, results from prospective trials showed neutral or adverse effects most likely due to differences in participant demographics, such as age, timing of initiation of treatment, and preexisting cardiovascular disease, which reflected in part the lack of basic science information on mechanisms of action of hormones on the vasculature at the time clinical trials were designed. The Kronos Early Estrogen Replacement Study (KEEPS) is a prospective, randomized, controlled trial designed, using findings from basic science studies, to test the hypothesis that MHT when initiated early in menopause reduces progression of atherosclerosis. KEEPS participants are younger, healthier, and within 3 years of menopause thus matching more closely demographics of women in prior observational and epidemiological studies than women in the Women’s Health Initiative hormone trials. KEEPS will provide information relevant to the critical timing hypothesis for MHT use in reducing risk for CVD

Hormone Treatment, Estrogen Receptor Polymorphisms and Mortality: A Prospective Cohort Study

International audienceBACKGROUND: The association between hormone treatment (HT) and mortality remains controversial. This study aimed to determine whether the risk of mortality associated with HT use varies depending on the specific characteristics of treatment and genetic variability in terms of the estrogen receptor. METHODOLOGY/PRINCIPAL FINDINGS: A prospective, population-based study of 5135 women aged 65 years and older who were recruited from three cities in France and followed over six years. Detailed information related to HT use was obtained and five estrogen receptor polymorphisms were genotyped. The total follow-up was 25,436 person-years and during this time 352 women died. Cancer (36.4%) and cardiovascular disease (19.3%) were the major causes of death. Cox proportional hazards models adjusted for age, education, centre, living situation, comorbidity, depression, physical and mental incapacities, indicated no significant association between HT and mortality, regardless of the type or duration of treatment, or the age at initiation. However, the association between HT and all-cause or cancer-related mortality varied across women, with significant interactions identified with three estrogen receptor polymorphisms (p-values = 0.004 to 0.03) in adjusted analyses. Women carrying the C allele of ESR1 rs2234693 had a decreased risk of all-cause mortality with HT (HR: 0.42, 95% CI: 0.18-0.97), while in stark contrast, those homozygous for the T allele had a significantly increased risk of cancer-related mortality (HR: 3.18, 95% CI: 1.23-8.20). The findings were similar for ESR1 rs9340799 and ESR2 rs1271572. CONCLUSIONS/SIGNIFICANCE: The risk of mortality was not associated with HT duration, type or age at initiation. It was however not equal across all women, with some women appearing genetically more vulnerable to the effects of HT in terms of their estrogen receptor genotype. These findings, if confirmed in another independent study, may help explain the differential susceptibility of women to the beneficial or adverse effects of HT

Evidence-based guidelines for the pharmacological treatment of postmenopausal osteoporosis: a consensus document by the Belgian Bone Club

Several drugs are available for the management of postmenopausal osteoporosis. This may, in daily practice, confuse the clinician. This manuscript offers an evidence-based update of previous treatment guidelines, with a critical assessment of the currently available efficacy data on all new chemical entities which were granted a marketing authorization. Osteoporosis is widely recognized as a major public health concern. The availability of new therapeutic agents makes clinical decision-making in osteoporosis more complex. Nation-specific guidelines are needed to take into consideration the specificities of each and every health care environment. The present manuscript is the result of a National Consensus, based on a systematic review and a critical appraisal of the currently available literature. It offers an evidence-based update of previous treatment guidelines, with the aim of providing clinicians with an unbiased assessment of osteoporosis treatment effect