Background: Average life expectancy has doubled over the last 200 years and therefore as quantity of life increased it is important to improve the quality of life as well and this can be through the promotion of lifestyle factors linked to providing a better protection against the development of chronic diseases. CVD is the worldwide number one cause, the second most common cause of death in developing countries and the leading cause of disability worldwide. In the UK, diseases of the heart and circulatory system are the main cause of premature (death before the age of 75) and normal death. Death rates for CHD have been falling rapidly in the UK since the late 1970s. However, death rates from CHD in the UK are still among the highest in Western Europe. Atherosclerosis and thrombotic events are the two main pathological features of CVD and the major cause for chronic vascular disease. Endothelium plays an important role in start and progress of atherosclerosis and Nitric oxide (NO) plays a key role in systemic physiological functions of the endothelium. Epidemiological and medical anthropological investigations suggest that flavonoid-rich foods, in particular those rich in flavanols exert cardiovascular health benefits which one of this benefits is through improvement of endothelium derived nitric oxide synthesis and bioavailability. The aim of this thesis was to assess impacts of acute ingestion of blueberry polyphenols, which are mainly anthocyanins and f1avanols, on blood pressure, platelet function and vascular function (through improvement in endothelium-dependant vasorelaxation).

'Previous studies (Brat, et al, 2006) have shown that the consumption of fruit and vegetables play a role in preventing the onset ot cardiovascular diseases, such as itherosclerosis, ischemic heart disease and coronary heart disease. These beneficial effects on cardiovascular health have been suggested to be due to the presence of polyphenolic compounds and perhaps their antioxidant capacity. The aim ot the study was to investigate whether dietary polyphenols have any direct ettects on vascular endothehal cell expression of genes involved in angiogenesis and other roles of the endothelium and whether physiological concentrations of the red wine polyphenols Quercetin and Resveratrol have a beneficial effect on vasoconstriction and vasodilation at the gene expression and protein expression level.

L’augmentation de l’obésité durant les dernières décennies expose la population à un risque accru de problèmes métaboliques et des maladies cardiovasculaires. Ce travail étudiait, d’une part, l’association de l’obésité avec la dysfonction diastolique et la rigidité artérielle aortique vingt ans plus tard chez des adultes initialement en bonne santé. Cette étude montrait que l’obésité générale mesurée par l’indice de masse corporelle et l’adiposité abdominale mesurée par le tour de taille étaient associées positivement à la dysfonction diastolique. Mais elles semblaient jouer un rôle protecteur sur la rigidité artérielle. Le ratio “tour de taille/indice de masse corporelle” semblait mieux isoler l’adiposité abdominale/viscérale de l’obésité générale, et était associé positivement à la rigidité artérielle. Il permettrait de montrer un rôle néfaste à long terme de l’adiposité abdominale/viscérale sur la rigidité artérielle même quand le poids est normal. La présence combinée de l’obésité abdominale (mesurée par le tour de taille) et d’un taux plus élevé de triglycérides était associée à un risque élevé de dysfonction diastolique. Dans la deuxième partie, nous nous sommes intéressés aux individus ayant déjà une hypertension artérielle. Ce travail montrait que, parmi les sujets ayant une hypertension, ceux ayant une hypertension non-diagnostiquée avaient un profil spécifique (plus souvent de sexe masculin, un tour de taille moins élevé, et moins souvent de maladies cardiovasculaires/diabète, antécédents familiaux d’hypertension et consultations de soins primaires moins fréquents). La présence concomitante d’un nombre élevé de ces critères renforçait fortement l’absence de primo-diagnostic. Nos résultats peuvent aider dans l’identification précoce des sujets à risque, la prévention et le management thérapeutique / Worldwide increasing obesity over the last decades expose the population to an increased risk of metabolic perturbations and cardiovascular diseases. This research investigated first the association of obesity with diastolic dysfunction and aortic stiffness observed 20 years later in initially healthy adults. General obesity measured with body mass index and abdominal adiposity measured with waist circumference were positively associated with diastolic dysfunction. But, these anthropometric parameters played a protective role in aortic stiffness. The ratio “waist circumference / body mass index” appeared to better isolate abdominal adiposity from general obesity and was then positively associated with aortic stiffness. It allowed to evidence a harmful role of abdominal adiposity in aortic stiffness, even in subjects with normal body weight. The presence of abdominal adiposity (measured with waist circumference) combined with an elevated level of triglycerides was associated with a higher risk of diastolic dysfunction. In the second part, our research focused on hypertensive individuals. It showed that among hypertensive subjects, those having undiagnosed-hypertension had specific features (being more often male, having less elevated waist circumference, and having fewer cardiovascular diseases/diabetes, familial hypertension history, and primary care uses). The concomitant presence of a higher number of these criteria appeared to strongly reinforce the absence of diagnosis. Our findings may help to early identify subjects at risk, and to establish prevention and therapeutic management