L’hyperglycémie associée au diabète de type 2 induit des complications vasculaires menant à des désordres cérébrovasculaires, comme l’accident vasculaire cérébral. En effet, l’hyperglycémie altère l’intégrité de la barrière hémato-encéphalique, et les cellules endothéliales cérébrales qui la composent sont particulièrement affectées. Le stress oxydant et l’état pro-inflammatoire engendrés par l’hyperglycémie jouent un rôle causal. Dans ce contexte, un intérêt croissant est accordé aux polyphénols d’origine végétale qui pourraient exercer une action antioxydante et anti-inflammatoire protectrice. L’objectif du travail de thèse était d’évaluer l’impact de l’hyperglycémie sur des marqueurs redox, inflammatoires et vasoactifs des cellules endothéliales cérébrales. L’action protectrice de l’insuline en tant qu’hormone hypoglycémiante clé a été explorée. De plus, nous avons étudié le rôle protecteur de polyphénols antioxydants extraits de la plante médicinale Antirhea borbonica de La Réunion. Pour ce faire, un modèle de cellules endothéliales cérébrales murines ainsi qu’un modèle animal d’ischémie cérébrale en condition d’hyperglycémie ont été utilisés. Nos résultats ont montré que l’hyperglycémie a induit un stress oxydant et une réponse pro-inflammatoire contribuant à une altération de la fonction endothéliale. Plusieurs cibles moléculaires ont été identifiées dont les protéines redox Nox4, Cu/ZnSOD, MnSOD, catalase et HO-1 ainsi que les facteurs vasoactifs ET-1, eNOS et NO. L’implication des médiateurs de signalisation Nrf2, AMPK, PI3K, JNK, ERK, p38 MAPK, NFκB et de la cytokine pro-inflammatoire IL-6 a été mise en évidence. L’insuline et les polyphénols ont exercé des effets antioxydants et anti- inflammatoires protégeant la fonction endothéliale. En situation d’ischémie cérébrale, l’hyperglycémie a exacerbé la dérégulation de l’état redox et pro-inflammatoire cérébral, associée à une altération de la barrière hémato-encéphalique. De plus, l’hyperglycémie a aggravé le déficit neurologique, le volume de l’infarctus cérébral et la transformation hémorragique. Les polyphénols ont exercé un rôle protecteur. L’acide caféique et son métabolite circulant, l’acide férulique, détectés au niveau cérébral, pourraient rendre compte de cette action protectrice. Des travaux complémentaires ont montré que les polyphénols protègent également contre l’altération de la fonction de cellules endothéliales aortiques humaines et la perte de vasorelaxation d’anneaux aortiques isolés de souris exposés à une hyperglycémie associée aux lipopolysaccharides de la bactérie Escherichia coli, qui sont des endotoxines liées de manière causale au contexte diabétique. En conclusion, ce travail de thèse a mis en évidence l’effet délétère de l’hyperglycémie sur la fonction endothéliale et le rôle protecteur de polyphénols antioxydants. L’utilisation des modèles expérimentaux développés permettra d’approfondir l’exploration des voies moléculaires impliquées et d’identifier de possibles cibles thérapeutiques innovantes. / Type 2 diabetes promotes vascular complications, leading to cerebrovascular disorders such as stroke. Indeed, hyperglycemia alters the blood-brain barrier integrity by deregulating the cerebral endothelial cell function. Oxidative stress and pro-inflammatory response may play a causal role. Thus, the biological effect of plant polyphenols known to exert antioxidant and anti-inflammatory capacities is of high interest. We evaluated the impact of hyperglycemia on the production of redox, inflammatory and vasoactive markers of cerebral endothelial cells, and the protective effect of polyphenols from the medicinal plant Antirhea borbonica from Reunion island. The murine bEnd.3 cerebral endothelial cells and an ischemia-reperfusion mouse model exposed to hyperglycemia were used. Our results demonstrated that hyperglycemia induced an oxidative stress and a pro-inflammatory state, leading to cerebral endothelial dysfunction through the activation of specific signaling molecules. Importantly, polyphenols extracted from Antirhea borbonica counteracted hyperglycemia deleterious effects and protected cerebral endothelial cells. Moreover, hyperglycemia exacerbated oxidative stress and pro-inflammatory state promoting cerebrovascular damages and loss of endothelial barrier integrity in ischemia-reperfusion mice model. Polyphenols exerted antioxidant and anti-inflammatory activities, attenuating cerebrovascular damages. These findings suggest that polyphenols extracted from Antirhea borbonica exerted protective effects on cerebral endothelial cells and an ischemia-reperfusion mouse model against deleterious effects of hyperglycemia.

A study of hyperglycemia and its effects on endothelial activation, macrophage recruitment, and atherosclerotic plaque development in mice. Hyperglycemic mice demonstrated greater VCAM but not ICAM expression along the endothelium, increased macrophage presence within the subendothelial space of these regions, and a greater volume of plaque in adulthood. / Cardiovascular disease is the leading cause of death in the world today. Atherosclerosis is the formation of plaque in the arteries and a major underlying cause of these fatalities. Type I and II diabetes are each strong independent risk factors for atherosclerosis. This study examines the effects of hyperglycemia on early atherosclerosis. Hyperglycemia did not promote atherosclerosis in the absence of hypercholesterolemia. Hyperglycemic mice demonstrated greater VCAM, but not ICAM, expression in regions of the endothelium susceptible to atherogenesis, prior to initiation of plaque development. Regions correlating to upregulation of VCAM exhibited a greater quantity of macrophages infiltrating the intima. This study suggests a unique and important role for VCAM in early atherosclerotic development and may explain the accelerated atherosclerotic plaque progression seen in hyperglycemic mice. This study also identifies VCAM as a potential target for the development of therapies to block or slow atherosclerotic plaque development in people with diabetes. / Thesis / Master of Science (MSc) / Cardiovascular disease is the leading cause of death in the world today. A major underlying cause of cardiovascular disease is atherosclerosis – a condition involving the thickening of the artery wall. Type I and II diabetes are each strong independent risk factors for atherosclerosis. The purpose of this study is to examine the effects of high blood glucose (hyperglycemia) on early events leading to atherosclerosis. This study found that hyperglycemia was not sufficient to promote atherosclerosis unless plasma cholesterol levels were also elevated. Hyperglycemia appeared to induce atherosclerosis by increasing the expression of factors responsible for recruiting white blood cells to the artery wall. This is consistent with the observation that hyperglycemic mice also had significantly more macrophages in the sites of plaque development. This study implicates one macrophage-recruitment factor in particular, vascular cell adhesion molecule (VCAM), as playing an important and unique role in the initiation of atherosclerosis by hyperglycemia. Therefore, VCAM is a possible target for the development of therapies to block or slow the development of atherosclerosis in individuals with diabetes.

Le diabète de type 1 (DT1) se caractérise par la destruction auto-immune des cellules ß des îlots de Langerhans du pancréas productrices d’insuline, entraînant un état d’hyperglycémie chronique. Malgré une prise en charge très fine de la maladie, s’appuyant sur l’insulinothérapie fonctionnelle, les personnes vivant avec le DT1 sont fréquemment sujettes à des épisodes hypoglycémiques et hyperglycémiques en raison de difficultés à adapter le traitement insulinique, notamment lors de l’activité physique. L’activité physique procure de nombreux bénéfices pour la santé que l’on ait ou non un diabète. Cependant, dans le cadre du DT1, les excursions glycémiques lors de l’activité physique peuvent conduire à des barrières à l’activité physique dans cette population ou peuvent limiter les performances sportives d’athlètes vivant avec le DT1. L’objectif de cette thèse était triple : 1) Étudier les barrières à l’activité physique chez les enfants et adultes vivant avec le DT1 et à leurs liens avec les excursions glycémiques réellement vécues dans la vie quotidienne et d’autant plus autour de l’activité physique, 2) Chez des enfants vivant avec le DT1, comparer deux types d’exercice (exercice aérobie continu vs. intermittent intense), représentatifs de leur activité physique spontanée, et explorer leurs effets sur les variations glycémiques à l’exercice et à la récupération précoce et tardive et, 3) Mesurer la glycémie en continu, à l’exercice et à la récupération, chez des sportifs en endurance qui n’ont pas de diabète, afin de comprendre les mécanismes impliqués dans la régulation de la glycémie lors d’épreuves d’ultra-endurance et de transposer ces résultats chez des sportifs vivant avec le DT1. Les résultats montrent que : 1) Chez les enfants, plus le temps passé <54 mg.dL-1 les nuits suivant les séances d'activités physiques augmente, plus la peur de l'hypoglycémie est importante. Chez les adultes, étonnamment, ceux qui déclarent le moins l’hypoglycémie comme une barrière à l’activité physique sont ceux qui ont le plus grand pourcentage de séances d’activités physiques entraînant une baisse de glycémie; 2) Le risque hypoglycémique n’est pas supérieur lors d’un exercice continu modéré représentatif de l’activité physique spontanée des enfants et, cet exercice semble efficace pour diminuer l’hyperglycémie retrouvée les jours inactifs sur la même période de temps; 3) Un risque hyperglycémique existe lors des phases intenses de la course et pendant 48 heures de récupération lors d’un ultra-trail réalisé chez des athlètes qui n’ont pas de diabète. Ce risque hyperglycémique à la récupération pourrait être en lien avec les dommages musculaires. / Type 1 diabetes (T1D) is characterized by the autoimmune destruction of the insulin-producing ß-cells of the islets of Langerhans in the pancreas, leading to a state of chronic hyperglycemia. Despite very sophisticated management of the disease, based on functional insulin therapy, people living with T1D are frequently subject to hypoglycemic and hyperglycemic episodes because of difficulties in adapting insulin treatment, particularly during physical activity. Physical activity has many health benefits, whether or not you have diabetes. However, in the context of T1D, glycemic excursions during physical activity may lead to barriers to physical activity in this population or may limit the sporting performance of athletes living with T1D. The aim of this thesis was threefold: 1) Investigate the barriers to physical activity in children and adults living with T1D and their links with the glycemic excursions actually experienced in daily life and all the more so around physical activity, 2) In children living with T1D, compare two exercise modalities (continuous aerobic exercise vs. intense intermittent), representative of their spontaneous physical activity, and explore their effects on glycemic variations during exercise and early and late recovery and, 3) Measure glycemia continuously, during exercise and recovery, in endurance athletes without diabetes in order to understand the mechanisms involved in regulating glycaemia during ultra-endurance events and transpose these results to athletes living with T1D. The results show that: 1) In children, the greater the time spent <54 mg.dL-1 on the nights following physical activity sessions, the greater the fear of hypoglycemia. Surprisingly, among adults, those who least reported hypoglycemia as a barrier to physical activity were those who had the highest percentage of physical activity sessions resulting in a drop in blood glucose levels; 2) The risk of hypoglycemia is no greater during continuous moderate exercise representative of the spontaneous physical activity of children, and this exercise appears to be effective in reducing the hyperglycemia found on inactive days over the same period of time; 3) A hyperglycemic risk exists during the intense phases of the race and during 48 hours of recovery during an ultra-trail run carried out in athletes who do not have diabetes. This hyperglycemic risk during recovery could be related to muscle damage.

The worldwide increasing number of persons affected by largely preventable diseases like diabetes demands better prevention and treatment. Insulin is required for effective utilisation of circulating nutrients. Impaired responsiveness to insulin (insulin resistance, IR) is a hallmark of type 2 diabetes and independently raises the risk of heart attack and stroke. The pathophysiology of IR is incompletely understood. High-throughput measurement of large numbers of circulating biomarkers may provide new insights beyond established risk factors. The aims of this thesis were to (i) use proteomics, metabolomics and genomics methods in large community samples to identify biomarkers of IR; (ii) assess biomarkers for risk prediction and insights into aetiology and consequences of IR; and (iii) use Mendelian randomisation analysis to assess causality. In Study I, analysis of 80 circulating proteins in 70-to-77-year-old Swedes identified cathepsin D as a biomarker for IR and highlighted a tentative causal effect of IR on raised plasma tissue plasminogen activator levels. In Study II, nontargeted fasting plasma metabolomics was used to discover 52 metabolites associated with glycaemic traits in non-diabetic 70-year-old men. Replication in independent samples of several thousand persons provided evidence for a causal effect of IR on reduced plasma oleic acid and palmitoleic acid levels. In Study III, nontargeted metabolomics in plasma samples obtained at three time points during an oral glucose challenge in 70-year-old men identified associations between a physiologic measure of IR and concentration changes in medium-chain acylcarnitines, monounsaturated fatty acids, bile acids and lysophosphatidylethanolamines. Study IV provided evidence in two large longitudinal cohorts for causal effects of type 2 diabetes and impaired insulin secretion on raised coronary artery disease risk. In conclusion, the Studies in this thesis provide new insights into the pathophysiology and adverse health consequences of IR and illustrate the value of combining traditional epidemiologic designs with recent molecular techniques and bioinformatics methods. The results provide limited evidence for the role of circulating proteins and small molecules in IR and require replication in separate studies and validation in experimental designs.

La fibrose kystique (FK) est la maladie autosomique récessive la plus fréquente chez les individus de race caucasienne. Elle est secondaire à la mutation du gène Cystic Fibrosis Transmembrane Regulator (CFTR). Grâce à des traitements plus agressifs, la médiane de l’espérance de vie des individus atteints de la FK a augmenté et cette augmentation est associée à l’émergence du diabète secondaire ou associé à la FK (DAFK), une complication associée à une augmentation du taux de mortalité. La pathophysiologie du DAFK n’est pas parfaitement comprise. Par exemple, la cause de l’accélération de la perte de la fonction pulmonaire, qui débute des années avant l’apparition du DAFK, n'est pas élucidée. Tous les patients atteints de la FK, même ceux sans le DAFK, présentent de l’hyperglycémie et des fluctuations glycémiques. D’ailleurs, une étude a démontré que la réactivité immunitaire est affectée par l’hyperglycémie dans un modèle animal de la FK et il y a des évidences que les lymphocytes sans CFTR fonctionnel ou en présence d’un excès de glucose ont des réactions inflammatoires anormales. Donc, nous avons émis l’hypothèse que les patients atteints de la FK, surtout ceux non-diabétiques et pré-diabétiques, auront une plus grande proportion de lymphocytes Th17 et Treg produisant la cytokine pro-inflammatoire IL-17A comparativement aux sujets sains et que l’augmentation de cette cytokine pourrait influencer la chute accélérée des fonctions pulmonaires avant l’apparition du DAFK. Des niveaux élevés d’IL-17A sont retrouvés dans les poumons des patients atteints de la FK et dans le sang périphérique des patients avec le diabète de type 1 (DT1) et de type 2 (DT2). L’IL-17A peut aussi être produite par les lymphocytes Treg dysfonctionnels. Habituellement, ces lymphocytes atténuent les réponses inflammatoires excessives, mais lorsqu’ils sont dysfonctionnels, ils peuvent produire de l’IL-17A, contribuant ainsi à l’état inflammatoire. De plus, nous avons supposé que les proportions de Th17 et Treg produisant de l’IL-17A seront associées aux fonctions pulmonaires des patients atteints de la FK et que l’alimentation, l’activité physique et la composition corporelle influenceraient ces relations. Les résultats de cette thèse ont montré que, malgré une association entre la proportion de lymphocytes dans le sang périphérique et les indices de fluctuations glycémiques, celles-ci n’influençaient pas les proportions de lymphocytes Th17 et Treg produisant de l’IL-17A lorsqu’ils étaient mis en culture pour 24 ou 48 heures dans des milieux contenant soit 5 mM ou 25 mM de glucose et stimulés par le phorbol 12-myristate 13-acetate (PMA) et le phytohemagglutinine (PHA) ou, encore, non stimulés. De plus, ces proportions étaient semblables entre les patients atteints de la FK et les individus en santé. Toutefois, les proportions de lymphocytes Treg stimulés produisant de l’IL-17A des sujets sains étaient plus élevées que les proportions de lymphocytes Treg non stimulés de tous les participants (patients atteints de la FK et individus en santé). Tout ceci suggérant donc que les Treg des sujets sains et atteints de la FK ne réagissaient pas de la même façon à la stimulation. D’ailleurs, la durée d’incubation affectait les proportions de Th17 produisant de l’IL-17A, mais elle n’avait aucun effet sur les proportions de Treg produisant cette cytokine. Donc, ces types cellulaires réagissaient différemment dans les mêmes milieux de culture. De plus, nous avons observé que seulement l’énergie provenant des glucides affectait modestement les indices de fluctuations glycémiques et que les proportions de Th17 et Treg produisant de l’IL-17A n’étaient pas associées aux fonctions pulmonaires des patients atteints de la FK. En conclusion, les patients atteints de la FK avaient plus d’hyperglycémie et de fluctuations glycémiques, mais elles n’influençaient pas les proportions de lymphocytes Th17 et Treg produisant de l’IL-17A ex vivo. Dans des études futures, il faudrait étudier le rôle de l’IL-17A dans les poumons des patients avec et sans le DAFK et réaliser une étude prospective pour déterminer si une augmentation des niveaux d’IL-17A chez les patients sans le DAFK se traduit par une chute accélérée des fonctions pulmonaires avant l’apparition de cette complication. / Cystic fibrosis (CF) is the most common autosomal recessive genetic disease among Caucasians and it is cause by a mutation in the Cystic Fibrosis Transmembrane Regulator (CFTR) gene. With the emergence of more aggressive therapies to treat CF, the median life expectancy of patients with CF has increased and new complications, such as CF-related diabetes (CFRD), have emerged. CFRD is associated with increased mortality. The physiopathology of this complication is not fully understood. For instance, the reason why people with CF have an accelerated decline in lung functions years before the diagnosis of CFRD is not known. Patients with CF, even those without CFRD, have increased hyperglycemia and glucose fluctuations. In addition, a study has reported that hyperglycemia affected immune reactivity in a mouse model of the disease. Furthermore, studies have shown that lymphocytes without a functional CFTR or that have increased uptake of glucose have abnormal immune responses. Therefore, we hypothesized that patients with CF, specifically those with normal and impaired glucose tolerance, would have increased proportions of Th17 and Treg lymphocytes producing the pro-inflammatory cytokine IL-17A and that the increase in IL-17A levels would contribute to the accelerated decline of lung functions before the onset of CFRD. Increased levels of IL-17A have been found in the lungs of patients with CF and the peripheral blood of patients with type 1 (T1D) and 2 diabetes (T2D). Dysfunctional Treg lymphocytes can also produce IL-17A. These lymphocytes usually attenuate excessive immune responses but, in certain cases, can be dysfunctional and produce the pro-inflammatory cytokine IL-17A. Moreover, we hypothesized that the proportions of these cells producing IL-17A would be associated to lung functions in patients with CF and that nutrition, physical activity and body composition could influence the relationship between inflammation and glucose fluctuations. Although an association between the proportion of lymphocytes in the peripheral blood of participants and glucose fluctuations was observed, glucose fluctuations did not affect the proportions of Th17 and Treg lymphocytes producing IL-17A stimulated with PHA and PMA or not stimulated in media containing either 5 or 25 mM of glucose for 24 or 48 hours. Furthermore, these proportions were similar between healthy individuals and patients with CF with the exception of the proportion of stimulated Treg lymphocytes producing IL-17A of healthy individuals that was greater than the proportions of non-stimulated Treg lymphocytes producing IL-17A of all participants (patients with CF and healthy individuals). This suggests that Treg lymphocytes of healthy individuals and CF patients do not respond in the same manner to stimulation by phorbol 12-myristate 13-acetate (PMA) and phytohemagglutinin (PHA). Also, the duration of incubation affected the proportions of Th17 cells producing IL-17A but did not affect the proportion of Treg producing this cytokine. Therefore, these two types of lymphocytes are differently affected in the same culture media. Also, only the proportion of calories from carbohydrates affected modestly glucose fluctuations and the proportions of Th17 and Treg lymphocytes producing IL-17A were not associated to lung functions in CF patients. To conclude, patients with CF had increased hyperglycemia and glucose flucutations when compared to healthy individuals but this glucose variability did not affect the proportions of Th17 and Treg lymphocytes producing IL-17A ex vivo. Future studies are needed to explore the role of IL-17A in the lungs of patients with CFRD and a prospective study would be important in order to determine if an increase in IL-17A in patients without CFRD is associated to an accelerated decrease in lung functions before the onset of this complication.

Introdução: Glicemia de jejum alterada tem sido associada a maior risco de desenvolver diabetes, comparando a indivíduos normoglicêmicos. Apesar de diabetes ser relacionado a aterosclerose e a piores desfechos cardiovasculares, os dados de literatura relacionando glicemia de jejum alterada à doença aterosclerótica são conflitantes. Os objetivos deste trabalho foram determinar (a) a incidência de diabetes em indivíduos com glicemia de jejum normal ou alterada em 1998 após um seguimento de até 12 anos; (b) se a glicemia de jejum alterada em 1998 e/ou diabetes incidente estiveram associados com aterosclerose subclínica no Estudo Longitudinal da Saúde do Adulto (ELSA-Brasil) ou à variável combinada de eventos clínicos não-fatais e escore de cálcio coronariano maior ou igual a 400. Métodos: Avaliamos 1.536 trabalhadores da Universidade de São Paulo, que participaram de um programa de avaliação em 1998 (idade 23-63 anos) e da linha de base do ELSA-Brasil (2008-2010). Apresentamos as taxas de incidência de diabetes brutas e ajustadas para todos os indivíduos e também estratificados por gênero e por índice de massa corpórea (IMC) em 1998. Utilizamos modelos de regressão brutos e ajustados para estimar a associação entre glicemia de jejum alterada em 1998 ou diabetes incidente com a espessura de íntima-média de carótidas (EIMC), escore de cálcio coronariano (CACS, do inglês Coronary Artery Calcium Score) e a variável composta CACS >= 400 ou eventos cardiovasculares incidentes (infarto do miocárdio ou revascularização). Resultados: Encontramos diabetes incidente em 177 indivíduos. A incidência de diabetes em nossa amostra foi de 9,8/1.000 pessoas-ano (Intervalo de confiança de 95% [IC95%]: 7,7-13,6). A incidência foi mais elevada entre os homens (11,2/1.000 pessoas-ano, IC95%: 8,6-15,0) do que entre as mulheres (8,5/1.000 pessoas-ano, IC95%: 5,3-15,3). Glicemia de jejum alterada em 1998 mostrou associação com maior risco de progressão para diabetes ao longo do seguimento (hazard ratio [HR]: 3,17; IC95%: 2,14-4,68) e HR: 7,42; IC95%: 4,75-11,57 para glicemias de jejum entre 100 e 109mg/dl e entre 110 e 125mg/dl, respectivamente). Glicemias entre 110 e 125mg/dl em 1998 foram associadas a maiores valores de EIMC (beta=+0,028; IC95%: 0,003 a 0,053) na linha de base do ELSA-Brasil. Ao excluir da análise aqueles com diabetes incidente, houve associação limítrofe, não-significativa, entre maiores valores de EIMC e glicemia de jejum entre 110 e 125mg/dl em 1998 (?=0,030; IC95%: -0,005 a 0,065). Ambos os níveis de glicemia de jejum alterada em 1998 não se mostraram associados ao CACS ou à variável composta de CACS >= 400 ou eventos cardiovasculares incidentes nos modelos de ajuste completo. Diabetes incidente foi associado a maiores valores de EIMC (em milímetros) (?=0,034; IC95%: 0,015 a 0,053), a CACS >= 400 (Razão de chances=2,84; IC95%: 1,17-6,91) e ao desfecho combinado de CACS >= 400 ou eventos cardiovasculares incidentes (Razão de chances=3,50; IC95%: 1,60-7,65). Conclusões: Glicemia de jejum alterada em 1998, especialmente nos valores mais próximos dos limiares de corte para diabetes, foram associados a maior incidência de diabetes ao longo do seguimento e a maiores valores de EIMC quando da avaliação inicial do ELSA-Brasil. Diabetes incidente entre as avaliações foi associado a maior risco cardiovascular / Introduction: Impaired fasting glucose has been associated with higher risk of incident diabetes, compared to normoglycemic individuals. Although diabetes mellitus is related to atherosclerosis and higher long-term cardiovascular burden, there are conflicting data about the association between impaired fasting glucose and atherosclerotic disease. We aimed (a) to determine diabetes incidence rates in individuals with normal or impaired fasting glucose in 1998 after follow-up of up to 12 years, (b) whether impaired fasting glucose in 1998 and/or incident diabetes were associated with subclinical atherosclerosis in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil) or the combined variable of non-fatal clinical events or a coronary calcium score >= 400. Methods: We evaluated 1,536 civil servants from the University of São Paulo, who participated in both 1998 (aged 23-63 years) and ELSA-Brasil baseline (2008-2010) assessments and had complete data. We presented crude and adjusted diabetes incident rates for all individuals and then stratified by sex and body mass index (BMI) in 1998. We used crude and adjusted regression models to estimate the association between impaired fasting glucose in 1998 or incident diabetes and coronary intima-media thickness (CIMT), coronary artery calcium score (CACS) and the composite variable of a CACS?400 or incident cardiovascular events (myocardial infarction or revascularization). Results: We found incident diabetes in 177 individuals. Diabetes incidence in our sample was 9.8/1,000 person-years (95% confidence interval [95%CI]:7.7-13.6). Diabetes incidence was higher in men (11.2/1,000 person-years, 95%CI: 8.6-15.0) than women (8.5/1,000 person-years, 95%CI: 5.3 to 15.3). Impaired fasting glucose in 1998 was associated with a higher risk of progression to diabetes during follow-up (hazard ratio [HR]: 3.17; 95%CI: 2.14-4.68 and HR: 7.42; 95%CI: 4.75-11.57 for a fasting plasma glucose between 100 to 109mg/dl and 110 to 125 mg/dl, respectively). Fasting plasma glucose levels between 110 to 125 mg/dl in 1998 were associated with higher CIMT (beta=+0.028; 95%CI: 0.003 to 0.053) in ELSA-Brasil baseline. Excluding those with incident diabetes, there was a non-significant borderline association between higher CIMT (in mm) and fasting plasma glucose 110 to 125mg/dl (beta=0.030; 95%CI: -0.005 to 0.065). Fasting plasma glucose levels in 1998 were not associated with CACS or the composite variable of a CACS ? 400 or incident cardiovascular events in full-adjusted models. Incident diabetes was associated with higher CIMT (in mm) (beta=0.034; 95%CI: 0.015 to 0.053), CACS >= 400 (OR=2.84; 95%CI: 1.17-6.91) and the combined outcome of a CACS >= 400 or incident cardiovascular event (OR=3.50; 95%CI: 1.60-7.65). Conclusions: Elevated fasting plasma glucose in 1998, especially those near diabetes diagnosis limits were associated with higher diabetes incidence during follow-up and higher CIMT in ELSA-Brasil baseline assessment. Incident diabetes between assessments was associated with higher cardiovascular burden

L’hyperglycémie de stress et la variabilité glycémique, consécutives à la réaction inflammatoire péri opératoire, sont associées à une morbidité et une mortalité accrues en chirurgie cardiaque. L’insulinothérapie intraveineuse administrée à l’aide de protocoles complexes, dits « dynamiques », constitue à l’heure actuelle le traitement de référence de l’hyperglycémie de stress. L’intérêt du contrôle glycémique péri-opératoire est admis par tous, sans qu’il existe de consensus véritable quant aux objectifs à atteindre, et reste très exigeant en termes de charge de soins. Dans la 1ère partie de ce travail, nous avons voulu vérifier si, 7 ans après sa mise en place, l’observance du protocole d’insulinothérapie utilisé dans notre Unité de Soins Intensifs de Chirurgie Cardiaque était conforme à celle mesurée lors de son implantation. Nous avons constaté des dérives majeures dans l’application du protocole qui ont pu être corrigées par la mise en place de mesures correctrices simples. Dans une 2ème partie du travail, nous avons cherché à évaluer si, à l’instar de la chirurgie cardiaque classique, une variabilité glycémique accrue était associée à une altération du pronostic des patients bénéficiant d’une procédure moins invasive (remplacement valvulaire aortique percutané ou TAVI). Nous avons ainsi analysé les données des patients ayant bénéficié d’un TAVI dans notre centre, et inclus dans les registres multicentriques français France et France-2. Nos résultats suggèrent une association entre une augmentation de la variabilité glycémique et un risque accru de complications cardiovasculaires majeures dans les 30 premiers jours, indépendamment de la qualité du contrôle glycémique obtenu. Enfin, dans une 3ème partie nous avons voulu savoir si exenatide, analogue de synthèse de GLP-1, permettait d’améliorer le contrôle glycémique péri opératoire en chirurgie cardiaque. Nous avons conduit un essai randomisé contrôlé de phase II/III montrant que l’administration intraveineuse (IV) d’exenatide, ne permettait pas d’améliorer la qualité du contrôle glycémique ou de réduire la variabilité glycémique par rapport à l’insuline IV, mais permettait de retarder l’administration d’insuline et de diminuer la quantité d’insuline administrée. Notre étude suggère également une diminution de la charge en soins. Du fait des données rapportées chez l’animal et dans l’infarctus du myocarde, nous avons également conduit une étude ancillaire suggérant l’absence d’effets cardioprotecteurs majeurs d’exenatide sur les lésions d’ischémie-reperfusion myocardiques, ne permettant pas d’améliorer la fonction cardiaque gauche à court et à moyen terme. L’optimisation du contrôle glycémique en chirurgie cardiaque nécessite ainsi la recherche de stratégies visant à améliorer l’observance des protocoles de soins et à réduire la variabilité glycémique. La place des analogues du GLP-1 reste à définir dans cette indication. / Stress hyperglycemia and glycemic variability are associated with increased morbidity and mortality in cardiac surgery patients. Intravenous (IV) insulin therapy using complex dynamic protocols is the gold standard treatment for stress hyperglycemia. If the optimal blood glucose target range remains a matter of debate, blood glucose control using IV insulin therapy protocols has become part of the good clinical practices during the postoperative period, but implies a significant increase in nurse workload. In the 1st part of the thesis, we aimed at checking the nurse-compliance to the insulin therapy protocol used in our Cardiac Surgery Intensive Care Unit 7 years after its implementation. Major deviations have been observed and simple corrective measures have restored a high level of nurse compliance. In the 2nd part of this thesis, we aimed at assessing whether blood glucose variability could be related to poor outcome in transcatheter aortic valve implantation (TAVI) patients, as reported in more invasive cardiac surgery procedures. The analysis of data from patients who undergone TAVI in our institution and included in the multicenter France and France-2 registries suggested that increased glycemic variability is associated with a higher rate of major adverse events occurring between the 3rd and the 30th day after TAVI, regardless of hyperglycemia. In the 3rd part if this thesis, we conducted a randomized controlled phase II/III trial to investigate the clinical effectiveness of IV exenatide in perioperative blood glucose control after coronary artery bypass graft surgery. Intravenous exenatide failed to improve blood glucose control and to decrease glycemic variability, but allowed to delay the start in insulin infusion and to lower the insulin dose required. Moreover, IV exenatide could allow a significant decrease in nurse workload. The ancillary analysis of this trial suggested that IV exenatide did neither provide cardio protective effect against myocardial ischemia-reperfusion injuries nor improve the left ventricular function by using IV exenatide. Strategies aiming at improving nurse compliance to insulin therapy protocols and at reducing blood glucose variability could be suitable to improve blood glucose control in cardiac surgery patients. The use of the analogues of GLP-1 in cardiac surgery patients needs to be investigated otherwise.

Introdução: Glicemia de jejum alterada tem sido associada a maior risco de desenvolver diabetes, comparando a indivíduos normoglicêmicos. Apesar de diabetes ser relacionado a aterosclerose e a piores desfechos cardiovasculares, os dados de literatura relacionando glicemia de jejum alterada à doença aterosclerótica são conflitantes. Os objetivos deste trabalho foram determinar (a) a incidência de diabetes em indivíduos com glicemia de jejum normal ou alterada em 1998 após um seguimento de até 12 anos; (b) se a glicemia de jejum alterada em 1998 e/ou diabetes incidente estiveram associados com aterosclerose subclínica no Estudo Longitudinal da Saúde do Adulto (ELSA-Brasil) ou à variável combinada de eventos clínicos não-fatais e escore de cálcio coronariano maior ou igual a 400. Métodos: Avaliamos 1.536 trabalhadores da Universidade de São Paulo, que participaram de um programa de avaliação em 1998 (idade 23-63 anos) e da linha de base do ELSA-Brasil (2008-2010). Apresentamos as taxas de incidência de diabetes brutas e ajustadas para todos os indivíduos e também estratificados por gênero e por índice de massa corpórea (IMC) em 1998. Utilizamos modelos de regressão brutos e ajustados para estimar a associação entre glicemia de jejum alterada em 1998 ou diabetes incidente com a espessura de íntima-média de carótidas (EIMC), escore de cálcio coronariano (CACS, do inglês Coronary Artery Calcium Score) e a variável composta CACS >= 400 ou eventos cardiovasculares incidentes (infarto do miocárdio ou revascularização). Resultados: Encontramos diabetes incidente em 177 indivíduos. A incidência de diabetes em nossa amostra foi de 9,8/1.000 pessoas-ano (Intervalo de confiança de 95% [IC95%]: 7,7-13,6). A incidência foi mais elevada entre os homens (11,2/1.000 pessoas-ano, IC95%: 8,6-15,0) do que entre as mulheres (8,5/1.000 pessoas-ano, IC95%: 5,3-15,3). Glicemia de jejum alterada em 1998 mostrou associação com maior risco de progressão para diabetes ao longo do seguimento (hazard ratio [HR]: 3,17; IC95%: 2,14-4,68) e HR: 7,42; IC95%: 4,75-11,57 para glicemias de jejum entre 100 e 109mg/dl e entre 110 e 125mg/dl, respectivamente). Glicemias entre 110 e 125mg/dl em 1998 foram associadas a maiores valores de EIMC (beta=+0,028; IC95%: 0,003 a 0,053) na linha de base do ELSA-Brasil. Ao excluir da análise aqueles com diabetes incidente, houve associação limítrofe, não-significativa, entre maiores valores de EIMC e glicemia de jejum entre 110 e 125mg/dl em 1998 (?=0,030; IC95%: -0,005 a 0,065). Ambos os níveis de glicemia de jejum alterada em 1998 não se mostraram associados ao CACS ou à variável composta de CACS >= 400 ou eventos cardiovasculares incidentes nos modelos de ajuste completo. Diabetes incidente foi associado a maiores valores de EIMC (em milímetros) (?=0,034; IC95%: 0,015 a 0,053), a CACS >= 400 (Razão de chances=2,84; IC95%: 1,17-6,91) e ao desfecho combinado de CACS >= 400 ou eventos cardiovasculares incidentes (Razão de chances=3,50; IC95%: 1,60-7,65). Conclusões: Glicemia de jejum alterada em 1998, especialmente nos valores mais próximos dos limiares de corte para diabetes, foram associados a maior incidência de diabetes ao longo do seguimento e a maiores valores de EIMC quando da avaliação inicial do ELSA-Brasil. Diabetes incidente entre as avaliações foi associado a maior risco cardiovascular / Introduction: Impaired fasting glucose has been associated with higher risk of incident diabetes, compared to normoglycemic individuals. Although diabetes mellitus is related to atherosclerosis and higher long-term cardiovascular burden, there are conflicting data about the association between impaired fasting glucose and atherosclerotic disease. We aimed (a) to determine diabetes incidence rates in individuals with normal or impaired fasting glucose in 1998 after follow-up of up to 12 years, (b) whether impaired fasting glucose in 1998 and/or incident diabetes were associated with subclinical atherosclerosis in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil) or the combined variable of non-fatal clinical events or a coronary calcium score >= 400. Methods: We evaluated 1,536 civil servants from the University of São Paulo, who participated in both 1998 (aged 23-63 years) and ELSA-Brasil baseline (2008-2010) assessments and had complete data. We presented crude and adjusted diabetes incident rates for all individuals and then stratified by sex and body mass index (BMI) in 1998. We used crude and adjusted regression models to estimate the association between impaired fasting glucose in 1998 or incident diabetes and coronary intima-media thickness (CIMT), coronary artery calcium score (CACS) and the composite variable of a CACS?400 or incident cardiovascular events (myocardial infarction or revascularization). Results: We found incident diabetes in 177 individuals. Diabetes incidence in our sample was 9.8/1,000 person-years (95% confidence interval [95%CI]:7.7-13.6). Diabetes incidence was higher in men (11.2/1,000 person-years, 95%CI: 8.6-15.0) than women (8.5/1,000 person-years, 95%CI: 5.3 to 15.3). Impaired fasting glucose in 1998 was associated with a higher risk of progression to diabetes during follow-up (hazard ratio [HR]: 3.17; 95%CI: 2.14-4.68 and HR: 7.42; 95%CI: 4.75-11.57 for a fasting plasma glucose between 100 to 109mg/dl and 110 to 125 mg/dl, respectively). Fasting plasma glucose levels between 110 to 125 mg/dl in 1998 were associated with higher CIMT (beta=+0.028; 95%CI: 0.003 to 0.053) in ELSA-Brasil baseline. Excluding those with incident diabetes, there was a non-significant borderline association between higher CIMT (in mm) and fasting plasma glucose 110 to 125mg/dl (beta=0.030; 95%CI: -0.005 to 0.065). Fasting plasma glucose levels in 1998 were not associated with CACS or the composite variable of a CACS ? 400 or incident cardiovascular events in full-adjusted models. Incident diabetes was associated with higher CIMT (in mm) (beta=0.034; 95%CI: 0.015 to 0.053), CACS >= 400 (OR=2.84; 95%CI: 1.17-6.91) and the combined outcome of a CACS >= 400 or incident cardiovascular event (OR=3.50; 95%CI: 1.60-7.65). Conclusions: Elevated fasting plasma glucose in 1998, especially those near diabetes diagnosis limits were associated with higher diabetes incidence during follow-up and higher CIMT in ELSA-Brasil baseline assessment. Incident diabetes between assessments was associated with higher cardiovascular burden