Indiana University-Purdue University Indianapolis (IUPUI) / For years, the leading killer of Americans has been coronary artery disease (CAD), which has a strong correlation to the U.S. obesity epidemic. Obesity, along with the presence of other risk factors including hyperglycemia, hypercholesterolemia, dyslipidemia, and high blood pressure, comprise of the diagnosis of metabolic syndrome (MetS). The presentation of multiple MetS risk factors increases a patients risk for adverse cardiovascular events. CAD is a complex progressive disease. We utilized the superb model of CAD and MetS, the Ossabaw miniature swine, to investigate underlying mechanisms of CAD progression. We studied the influence of coronary epicardial adipose tissue (cEAT) and coronary smooth muscle cell (CSM) intracellular Ca2+ regulation on CAD progression. By surgical excision of cEAT from MetS Ossabaw, we observed an attenuation of CAD progression. This finding provides evidence for a link between local cEAT and CAD progression. Intracellular Ca2+ is a tightly regulated messenger in CSM that initiates contraction, translation, proliferation and migration. When regulation is lost, CSM dedifferentiate from their mature, contractile phenotype found in the healthy vascular wall to a synthetic, proliferative phenotype. Synthetic CSM are found in intimal plaque of CAD patients. We investigated the changes in intracellular Ca2+ signaling in enzymatically isolated CSM from Ossabaw swine with varying stages of CAD using the fluorescent Ca2+ indicator, fura-2. This time course study revealed heightened Ca2+ signaling in early CAD followed by a significant drop off in late stage calcified plaque. Coronary artery calcification (CAC) is a result of dedifferentiation into an osteogenic CSM that secretes hydroxyapatite in the extracellular matrix. CAC is clinically detected by computed tomography (CT). Microcalcifications have been linked to plaque instability/rupture and cannot be detected by CT. We used 18F-NaF positron emission tomography (PET) to detect CAC in Ossabaw swine with early stage CAD shown by mild neointimal thickening. This study validated 18F-NaF PET as a diagnostic tool for early, molecular CAC at a stage prior to lesions detectable by CT. This is the first report showing non-invasive PET resolution of CAC and CSMC Ca2+ dysfunction at an early stage previously only characterized by invasive cellular Ca2+ imaging.

Thesis (PhD)-- Stellenbosch University, 2014. / ENGLISH ABSTRACT: Introduction: The cardioprotective actions of the hormone melatonin against myocardial ischaemiareperfusion injury (IRI) are well-established. It has recently been shown to prevent the harmful effects of hyperphagia-induced obesity on the susceptibility of the heart to IRI as well as many of the harmful effects of obesity and insulin resistance. However, the exact mechanism whereby it exerts its beneficial action is still unknown. The aims of this study were to determine the effects of relatively short-term melatonin treatment in a rat model of diet-induced obesity on: (i) biometric and metabolic parameters, lipid peroxidation, myocardial IRI and intracellular signalling (ii) mitochondrial oxidative phosphorylation function (iii) cardiomyocyte glucose uptake and intracellular signalling. In addition, the effects of acute melatonin treatment of cardiac microvascular endothelial cells (CMEC) were determined on cell viability, nitric oxide production (NO), TNF- -induced dysfunction and intracellular signalling. Material and Methods: Male Wistar rats were randomly allocated to two groups for 20 weeks feeding with either standard rat chow or a high calorie diet. Each group was subdivided into 3 groups receiving either water throughout or melatonin (4mg/kg/day, in the drinking water) for the last 6 or 3 weeks of the experimental programme. Hearts, perfused in the working mode, were subjected to ischaemia/reperfusion and infarct size determined. Mitochondria and cardiomyocytes were isolated according to standard techniques and oxidative function and glucose uptake respectively determined. CMEC NO production and cell viability were quantified by FACS analysis of the fluorescent probes, DAF-2/DA and propidium iodide/Annexin V respectively. Intracellular signalling was evaluated using Western blot and appropriate antibodies. Results: The high-calorie diet caused significant increases in body weight gain, visceral adiposity, fasting blood glucose, serum insulin, triglycerides, HOMA-IR index and a concomitant reduction in serum adiponectin levels as well as larger myocardial infarct sizes after exposure to IRI compared to the control, indicating increased susceptibility to damage. Three as well as six weeks of melatonin administration to obese and insulin resistant rats reduced serum insulin levels and the HOMA-IR index. Myocardial infarct size was reduced in both control and diet groups. These effects were associated with increased activation of baseline myocardial STAT- 3 and the RISK pathway during reperfusion. The diet had no effect on the oxidative phosphorylation capacity of mitochondria, isolated from non-perfused hearts (baseline), but melatonin administration for 6 weeks induced a reduction in state 3 respiration rate; mitochondria isolated from diet hearts subjected to global ischaemia, exhibited an attenuated oxidative phosphorylation process which was improved by melatonin treatment. Melatonin in vitro enhanced cardiomycyte insulin stimulated glucose uptake of normal young rats but not of insulin resistant rats. In vivo melatonin treatment for 6 weeks increased basal (in diet group) and insulin stimulated glucose uptake in both control and diet groups. Melatonin (1nM) in vitro caused a significant reduction in necrosis and apoptosis of cultured CMEC, associated with a decrease in nitric oxide availability and eNOS activation and a concomitant increase in PKB/Akt, p38MAPK and AMPK activation. The harmful effects of TNF- treatment on signalling in CMEC could be prevented by co-treatment with melatonin. Conclusions: The results suggest that short-term melatonin treatment was able to significantly attenuate the diet-induced increased myocardial susceptibility to ischaemia/reperfusion damage. It may also improve cardiac glucose homeostasis and mitochondrial oxidative phosphorylation in an insulin resistant state. Melatonin in vitro protects CMEC against apoptosis and necrosis and reduces nitric oxide availability. These beneficial effects of melatonin may ultimately be due to its antioxidant capacity or receptor-mediated actions, but this remains to be established. / AFRIKAANSE OPSOMMING: Inleiding: Die vermoë van die hormoon, melatonien, om die hart teen iskemie/ herperfusiebesering (IHB) te beskerm, is welbekend. Onlangs is ook getoon dat melatonien IHB en verskeie van die nadelige effekte van vetsug en insulienweerstandigheid in hiperfagiegeïnduseerde vetsug kan voorkom. Die meganisme(s) betrokke by hierdie voordelige prosesse is egter grootliks onbekend. Die doel van hierdie studie was om die gevolge van korttermyn melatonienbehandeling in ‘n model van hiperfagiegeïnduseerde vetsug te ondersoek op (i) biometriese en metaboliese parameters, lipiedperoksidasie, miokardiale IHB en intrasellulêre seintransduksie, (ii) mitochondriale oksidatiewe fosforilasie, (iii) glukoseopname en intrasellulêre seintransduksie in kardiomiosiete en aanvullend, (iv) die invloed van akute melatonienbehandeling van kardiale mikrovaskulêre endoteelselle op sellulêre oorlewing, stikstofoksiedproduksie, TNF- - geïnduseerde disfunksie en seintransduksie. Metodiek: Manlike Wistarrotte is ewekansig in twee groep verdeel en vir 20 weke met standaard-rotkos of ‘n hoëkaloriedieet gevoer. Elke groep is in 3 subgroepe verdeel, wat deurgaans water of melatonien (4mg/kg/dag in die drinkwater) vir 3 of 6 weke voor die beëindiging van die eksperiment ontvang het. Harte is geperfuseer volgens die werkharttegniek, blootgestel aan iskemie/herperfusie en die infarktgrootte bepaal. Mitochondria en kardiomiosiete is volgens standaardtegnieke geïsoleer vir bepaling van oksidatiewe funksie en glukoseopname respektiewelik. NO produksie en sellewensvatbaarheid was gekwantifiseer deur vloeisitometriese analises (FACS) van die fluoresserende agense, DAF-2/DA en propidium jodied/Annexin V onderskeidelik. Intrasellulêre seintransduksie is evalueer met behulp van die Western kladtegniek en geskikte antiliggame. Resultate: Die hoëkaloriedieet het ‘n beduidende toename in liggaamsgewig, visserale vet, vastende bloedglukose, seruminsulienvlakke, trigliseriede, HOMA-IR-indeks en ‘n gepaardgaande verlaging in serumadiponektienvlakke tot gevolg gehad, sowel as groter miokardiale infarkte na iskemie/herperfusie. Laasgenoemde dui op ‘n groter vatbaarheid vir iskemiese beskadiging in harte van vetsugtige diere. Drie sowel as ses weke van melatonienbehandeling het die seruminsulienvlakke en HOMAindeks in vetsugtige diere beduidend verlaag, vergeleke met die kontroles. Miokardiale infarktgroottes was verminder in beide kontrole- en vetsuggroepe. Hierdie effekte het met ‘n verhoogde aktivering van basislyn STAT-3 en PKB/Akt en ERKp44/p42 tydens herperfusie gepaard gegaan. Die dieet het geen invloed op die oksidatiewe fosforilasiekapasiteit van mitochondria, geïsoleer uit harte van ongeperfuseerde harte, gehad nie (basislyn), maar melatonienbehandeling vir 6 weke het Staat 3 respirasie verlaag. Mitochondria, geïsoleer uit harte van vetsugtige rotte wat aan globale iskemie onderwerp was, het ‘n onderdrukte oksidatiewe fosforilasieproses gehad, wat egter deur melatonienbehandeling verbeter is. Melatonien in vitro het insuliengestimuleerde glukoseopname deur kardiomiosiete van jong, maar nie vetsugtige rotte nie, verhoog. In vivo melatonientoediening vir 6 weke het egter basale (in die dieetgroep) en insuliengestimuleerde glukoseopname in beide kontrole- en vetsuggroepe verhoog. Toediening van melatonien in vitro aan mikrovaskulêre endoteelselkulture het ‘n beduidende afname in nekrose, apoptose, stikstofoksied- beskikbaarheid en eNOS aktivering teweeggebring, tesame met ‘n verhoogde aktivering van PKB/Akt, p38MAPK en AMPK. Die nadelige effekte van TNF- toediening op seintransduksie in die mikrovaskulêre endoteelselle is deur melatonien voorkom. Gevogtrekkings: Die resultate toon dat melatonien ‘n merkwaardige beskermende effek op die toename in vatbaarheid vir iskemiese beskadiging in vetsugtige rotte gehad het. Dit mag ook miokardiale glukose-homeostase en mitochondriale oksidatiewe funksie in insulienweerstandigheid verbeter. Melatonien in vitro beskerm mikrovaskulêre endoteelselle teen nekrose asook apoptose en verminder die beskikbaarheid van stikstofoksied. Hierdie voordelige effekte van melatonien mag aan sy anti-oksidantvermoëns of stimulasie van die melatonienreseptor toegeskryf word, maar bewyse daarvoor ontbreek nog. / Division of Medical Physiology (Stellenbosch University), / National Research Foundation / Harry Crossley Foundation

Aging, obesity and increased waist circumference (WC) increases risk for metabolic syndrome (MetS). MetS is a cluster of symptoms (elevated WC, triglycerides, blood pressure, fasting glucose, and decreased high-density lipoprotein cholesterol [HDL-C]) increasing risk for chronic disease. Low-energy dense (LED) diets, emphasizing whole food eating patterns, have not been examined in combination with moderate (mod)/high-intensity physical activity (PA) or dietary protein levels to determine their impact on changes in body weight (BW) and WC in premenopausal, abdominally obese women. PURPOSE: To determine the effect of two 16-wk diet and PA interventions, differing in protein intake, on BW, WC, MetS risk factors, dietary patterns, energy density (ED), and min of Mod-Hi PA. METHODS: Healthy, abdominally obese (WC≥80cm) women (n=38; 34±10y) were randomly assigned to either a 15 or 25% (+18 g/d whey protein) en from protein diet. Individualized LED diets plans decreased energy intake (EI) by ~300kcal/d; PA 5 d/wk (30-60 min/d) consisted of supervised, high-intensity Zumba classes 3d/wk (≥65%HRmax; ≥6METs) and self-selected mod-intensity PA (≥3METs) 2d/wk. Servings of fruits/vegetables, whole grains, and low-fat/fat-free dairy (LFD), fiber, high calorie beverages (BEV), ED, and PA were monitored before (T1), during (T2) and after (T3) the intervention using repeated measures ANOVA. Bonferroni simultaneous testing procedure was used in analysis of multiple comparisons. RESULTS: At T1, groups did not differ in dietary patterns, PA, BW, WC, or MetS risk. Groups responded similarly to the interventions so data were combined, with BW and WC decreasing (p<0.0001) by -4.8±2.7kg and -7.1±3.6cm, respectively. Comparing T1 vs. T2, there were increases (p<0.0001) in fruits/vegetables, (Δ=+1.5 ser/d), whole grains (Δ=+1.0 ser/d), LFD (Δ=+0.5 ser/d), fiber (Δ=+5.7g/1000 kcal), and decreases in BEV (Δ=-165 kcal/d) and ED (Δ=-0.55 kcal/g). During the intervention high-intensity Zumba PA was 87min/wk; total min of all mod-intensity PA increased by 75 min/d (p<0.0001); VO2max improved from 29.3±4.7 (T1) to 34.4±5.3 (T3) mL/kg/min (p<0.0001). Triglycerides significantly decreased (-24±52 mg/dl; p=0.006), no other significant changes occurred in MetS risk factors. Exploratory analysis indicated that increases in fruits/vegetables and LFD, and decreases ED were associated with BW loss, while increases in whole grains, fiber, LFD, and min/wk of high-intensity PA (Zumba) were associated with WC reductions. CONCLUSION: For abdominally obese women, an intervention focused on LED foods and high-intensity PA significantly reduced BW and WC and improved dietary patterns regardless of protein intake. Helping clients identify a few key factors that positively promote reductions in BW and WC may improve weight loss success, while reducing MetS risk factors. / Graduation date: 2012

Objectives: To examine variation in clustered metabolic risk (cMetS) in adolescents classified as not overweight/active (NOA), not overweight/not active (NONA), overweight/active (OA), and overweight/not active (ONA). Background: While studies to date have shown that children and adolescents who meet the current physical activity (PA) recommendations and maintain a healthy body weight demonstrate significantly lower cardiometabolic risk, there are some studies that suggest the relationship between PA and metabolic risk may be mediated by adiposity. Methods: The sample included adolescent participants (n=875; 12-17 years) of the 2007-2012 National Health and Nutrition Examination Survey (NHANES). The cMetS score included triglycerides, high-density lipoprotein cholesterol, fasting plasma glucose, and mean arterial pressure. Age- and sex-specific body mass index (BMI) percentiles were utilized; overweight was defined as BMI percentile ≥ 85th. Activity data included self-reported frequency of moderate-to-vigorous PA. Adolescents reporting ≥ 60 min/day of PA were considered “active”. General linear models, adjusted for age, sex, and race-ethnicity, were used. A six-year fasting sample weight was applied to the analyses in order to ensure representativeness of the data. Results: The cMetS scores were significantly (p Conclusions: The cMetS scores were higher in OA and ONA adolescents when compared to those classified as NOA. Whereas only ONA males demonstrated significantly higher cMetS score when compared to the NOA referent, both OA and ONA cMetS scores (vs NOA) were significantly higher in females.

<p>Gojaznost se najče&scaron;će defini&scaron;e kao uvećanje udela masne mase u ukupnoj telesnoj masi. Danas gojaznost poprima pandemijske razmere i karakter globalnog zdravstveno-socijalnog problema jer predstavlja faktor rizika za razvoj masovnih nezaraznih bolesti, pre svega tipa 2 &scaron;ećerne bolesti (T2DM) i kardiovaskularnih bolesti. Adipokini su molekule koje luči masno tkivo i koji imaju značajnu ulogu u regulaciji mnogobrojnih procesa u ljudskom organizmu. Adiponektin (ADN) je adipokin sa antidijabetogenim, antiinflamatornim i antiaterogenim dejstvom. Tokom razvoja, pre svega, centralnog tipa gojaznosti dolazi do poremećaja u sekretornom profilu masnog tkiva, nastaje pad serumske koncentracije ADN i dolazi do razvoja mnogobrojnih kardiometaboličkih poremećaja. Cilj rada je ispitivanje značaja određivanja serumskog ADN u proceni kardiometaboličkog profila i utvrđivanje povezanosti njegovog nivoa sa procenjenim desetogodi&scaron;njim rizikom za razvoj T2DM kod gojaznih osoba. Studija preseka sprovedena na Klinici za endokrinologiju, dijabetes i bolesti metabolizma, Kliničkog centra Vojvodine je obuhvatila 65 ispitanika sa hiperalimentacionim tipom gojaznosti. Kod ispitanika je procenjen desetogodi&scaron;nji rizik za razvoj T2DM i sprovedena su odgovarajuća antropometrijska, laboratorijska i morfolo&scaron;ka ispitivanja. Ispitanici sa sniženim serumskim ADN su imali nepovoljniji kardiometabolički profil u odnosu na ispitanike sa normalnom vredno&scaron;ću serumskog ADN dok nije bilo razlike u nivou desetogodi&scaron;njeg rizika za razvoj T2DM između navedenih grupa. Takođe, ispitanici sa metaboličkim sindromom (MS) i ispitanici sa nealkoholnom masnom bole&scaron;ću jetre (NAFLD) su imali niži serumski ADN u odnosu na osobe bez MS i osobe bez NAFLD. Kod gojaznih osoba postoji značajna povezanost serumskog ADN sa većim brojem pokazatelja kardometaboličkog profila ali ne i sa procenjenim desetogodi&scaron;njim rizikom za razvoj T2DM.</p> / <p>Obesity is often defined as the significant increase in proportion of fat mass in total body mass. Nowadays, obesity exhibits pandemic proportions and acquires character of the global health and social problem, as it represents the risk factor for the development of non-communicable diseases, especially type 2 diabetes mellitus (T2DM) and cardiovascular diseases. Adipokines are molecules secreted by adipose tissue which play an important role in the regulation of various processes in the human organism. Adiponectin (ADN) is an adipokine with anti-diabetic, anti-inflammatory and anti-atherogenic effects. During development of, above all, central obesity, disorders in the secretory profile of adipose tissue are arising, decline in serum concentrations of ADN advents, which leads to occurrence of numerous cardiometabolic disorders. The aim of study is to examine the significance of determining serum ADN in assessing the cardiometabolic profile, and determining its association with the estimated ten-year risk of developing T2DM in obese persons. Cross-sectional study conducted at the Clinic for Endocrinology, Diabetes and Metabolic Disorders, Clinical Center of Vojvodina, included 65 persons with hyperalimentation type of obesity. Ten-year risk of developing T2DM was assessed and appropriate anthropometric, laboratory and morphological evaluations were performed. Persons with lower serum ADN had worse cardiometabolic profile compared to those with normal serum ADN value, while there was no difference in the level of ten-year risk of developing T2DM between two groups. Also, subjects with metabolic syndrome (MS) and subjects with nonalcoholic fatty liver disease (NAFLD) had lower serum ADN compared to persons without MS and to those without NAFLD. There is a significant association of serum ADN with a larger number of cardiometabolic profile indicators but not with the estimated ten-year risk of developing T2DM.</p>

Ce travail a été réalisé avec l'appui du Centre Collaborateur de l'OMS sur la Transition Nutritionnelle et le Développement (TRANSNUT) de l'Université de Montréal, en collaboration avec deux parténaires du Bénin: l'Institut de Sciences Biomédicales Appliquées (ISBA) de Cotonou et l'Institut Régional de Santé Publique de Ouidah. / L’étude visait à décrire la transition nutritionnelle et ses liens avec des facteurs de risque de maladies cardiovasculaires (MCV) dans une ville secondaire du Bénin et dans ses environs ruraux, puis de comparer à cet égard, les habitants de la petite ville avec ceux du milieu rural et de la métropole. Les sujets de 25 à 60 ans (n = 541), apparemment en bonne santé, ont été aléatoirement sélectionnés dans la petite ville de Ouidah (n = 171), sa périphérie rurale (n = 170) et dans la métropole Cotonou (n = 200). Les apports alimentaires et l’activité physique ont été cernés par trois rappels de 24 heures. Les données socioéconomiques ont été recueillies par questionnaire. La qualité de l’alimentation a été évaluée par un score de diversité alimentaire, un score d’adéquation en micronutriments et un score de prévention contre les maladies chroniques. Des mesures anthropométriques et de composition corporelle ont été prises. La tension artérielle a été mesurée. Des échantillons sanguins ont été prélevés pour déterminer le profil lipidique à l’aide du sérum et la glycémie à jeun plasmatique. La transition alimentaire était plus poussée dans la métropole que dans la petite ville et le milieu rural, et elle était marquée par des apports plus importants en viande, produits laitiers, œufs, légumes et huiles, mais plus faibles en céréales, poisson, légumineuses, fruits et fibres. La diversité alimentaire y était plus élevée, mais l’adéquation en micronutriments et la prévention étaient plus faibles que dans les autres sites. Il n’y avait pas de différences majeures entre le milieu rural et la petite ville pour la consommation et la qualité alimentaire. L’influence du niveau socioéconomique sur l’alimentation et sa qualité était surtout marquée dans la métropole. Un gradient positif du milieu rural vers la petite ville et la métropole a été observé pour l’obésité générale (8,8%; 12,3%; 18%, p = 0,031) et abdominale (28,2%, 41,5%, 52,5%; P<0,001) et pour le syndrome métabolique (4,1% ; 6,4% ; 11%; P = 0,035) d’après les critères de la Fédération Internationale de Diabète. La fréquence de tension artérielle élevée [TAE] (24,1% ; 21,6% et 26,5%, respectivement pour le milieu rural, la petite ville et la métropole), bien qu’importante, n’était pas significativement différente selon les sites. Le HDL-cholestérol bas était moins fréquent dans la petite ville (18,1%) par rapport au milieu rural (25,3%) et à la métropole (37,5%). L’activité physique, plus importante en milieu rural et en petite ville que dans la métropole, était protectrice contre des valeurs élevées d’IMC (ß = -0,145 ; p<0,01), de tour de taille (ß = -0,156 ; p<0,001), de tension systolique (ß = -0,134 ; p<0,01) et diastolique (ß = -0,112, p<0,01), et de triglycérides (ß = -0,098 ; p<0,05). La consommation de légumes était négativement et indépendamment associée à la tension artérielle diastolique (ß = -0,129, p<0,01), alors que celle de poisson était positivement associée au HDL-cholestérol (ß = 0,168 ; p<0,01). L’adéquation en micronutriments était positivement associée au HDL-cholestérol (ß = 0,144; p<0,01) et à un moindre risque de tension artérielle élevée (OR = 0,46 ; IC 95% : 0,26-0,84). L’étude a confirmé l’existence d’un plus grand risque de MCV avec l’urbanisation, un stade plus avancé de transition alimentaire et un mode de vie sédentaire. Ce risque pourrait être réduit par la promotion d’un mode de vie plus actif associé à des apports plus adéquats en micronutriments et une consommation élevée de poisson et de légumes. //// / The purpose of this study was to describe the nutrition transition and its links with cardiovascular disease (CVD) risk factors in a small-size city of Benin and its rural outskirts, and to compare in this regard, the small-size city and the rural area with the major city. A sample of 541 apparently healthy subjects aged 25-60 years was randomly selected from Ouidah, a small-size city of Benin (n = 171), the rural outskirts of Ouidah (n = 170), and Cotonou, the major city (n= 200). Dietary intake and physical activity were assessed with three non consecutives 24-hour recalls. Socioeconomic data were collected by questionnaire. Dietary quality was assessed using a dietary diversity score, a micronutrient adequacy score and a healthfulness score. Blood pressure was measured. Anthropometric measurements were taken. Blood samples were collected to determine serum lipid profile and plasma glucose. A more advanced stage of dietary transition was observed in the major city, which was characterised by higher intakes of meat, milk products, eggs, vegetables and oils, but lower intakes of cereal, fish, legumes, fruit and fibre than the small-size city and the rural area. Dietary diversity was higher in the major city, while micronutrient adequacy and healthfulness scores were lower compared to the small city and the rural area. There was no significant difference in diet and diet quality scores between the small-size city and the rural area. Socioeconomic factors had a strong influence on diet and its quality in the major city. A positive gradient from the rural area to the small-size city to the major city was observed in the prevalence of overall obesity (18%, 12.3%, 8.8%, p = 0.031), abdominal obesity (28.2%, 41.5%, 52.5%; P<0,001) and the metabolic syndrome (4.1%; 6.4%; 11%; p = 0.035) according to the International Diabetes Federation criteria. The prevalence of elevated blood pressure was high, but did not differ across sites (24.1%, 21.6%, 26.5% for rural, small-size city and major city, respectively). The prevalence of low HDL-cholesterol was lower in the small-city (18.1%) compared to the rural area (25.3%) and the major city (37.5%), while fasting plasma glucose was more highly prevalent in the small city (14.6%) and the rural area (10%) compared to the major city (4%). Elevated triglycerides were uncommon. Physical activity was higher in the rural area and small-size city than in the major city, and it was protective against elevated body mass index (ß = -0.145; p<0.01), waist circumference (ß = -0.156; p<0.001), systolic (ß = -0.134; p<0.01) and diastolic (ß = -0.112, p<0.01) blood pressure, and triglycerides (ß = -0,098; p<0,05). Vegetable intakes were negatively and independently associated with diastolic blood pressure, while fish intake was positively associated with HDL-cholesterol. Micronutrient adequacy score was positively associated with HDL-cholesterol (ß = 0,144; p<0,01) and with a lower likelihood of high blood pressure (OR = 0.46; CI 95%: 0.26-0.84). The study confirmed a higher CVD risk with urbanization, advanced stage of dietary transition and a sedentary lifestyle. This risk could be curtailed by improving micronutrient adequacy and increasing vegetables and fish consumption, and by promoting an active lifestyle.

L’hypertension artérielle et l’obésité sont deux composantes conjointement reliées du syndrome métabolique. Les récepteurs de l’ANP (GCA) et de l’oxyde nitrique (GCs) ont des propriétés diurétiques, natriurétiques, vasodilatatrices et sont liés au contrôle de la pression. Des études récentes ont démontré leur implication dans l’obésité. Hypothèse : Une différence génétique au niveau du gène GCA pourrait contribuer à des différences physiologiques. La composante lipidique et/ou sodique de la diète pourrait influencer la fonction rénale, cardiaque et les valeurs anthropométriques différemment chez les souches congéniques. Objectifs : (1) Déterminer l’effet de la composante lipidique et sodique des diètes; (2) Évaluer l’influence de GCA sur la réponse physiologique des souches congéniques; (3) Expliquer les mécanismes physiologiques procurant une réduction de la pression artérielle chez la souche SM9. Méthodologie : Des modèles congéniques du rat Dahl (DSS) hypertendu, nourri avec une diète riche en gras (HF) ou normale (NF), ont été utilisés pour démontrer l’impact d’un segment chromosomique d’origine normotendue. Résultats : La souche SM9 a une prise de poids plus importante que SM12 et DSS sur diète HF malgré un apport alimentaire équivalent. La souche SM9 présente également un ratio masse adipeuse/masse maigre plus élevé que SM12 et DSS. Nous n’avons observé aucune augmentation de la pression artérielle en réponse à la diète HF pour les 3 souches malgré une augmentation du dommage rénal pour les 3 souches. Le dommage rénal est plus important chez DSS que pour les 2 congéniques. La réponse diurétique à l’ANP est plus élevée chez SM9 et est influencée par le contenu en sel dand la diète. La perte glomérulaire plus importante chez le rat DSS semble compensée par une augmentation de la réponse à l’ANP par les glomérules résiduels. Il y a une corrélation entre l’activité de GCA en réponse à l’ANP, les niveaux d’ARNm et le nombre de répétition du dinucléotide TA dans son promoteur. Le rat DSS présente une hypertrophie cardiaque plus importante que les deux souches congénique et ceci n’est pas modifié par la diète HF. Conclusion : Nos études ont permis de mettre en évidence un effet génétique impliquant le segment chromosomique normotendu contenant GCA dans la réponse à une diète HF chez le rat DSS. / Hypertension and obesity are two related components of the metabolic syndrome. The ANP receptor (GCA) and nitric oxide receptor (sGC) have diuretic, natriuretic, vasodilatory properties, and are linked to blood pressure control. Furthermore a recent study has demonstrated the implication of GCA and sGC in the development of obesity. Hypothesis: A genetic difference in GCA gene could contribute to physiological differences. The differencial lipid and/or sodium composition of the diet could influence the renal, cardiac and anthropometric values. Objectives: (1) To determine the effect of fat and sodium on the physiological parameters; (2) To evaluate the influence of GCA on the physiological response of the congenic rat; (3) To explain the mechanisms of the blood pressure reduction in SM9 rats. Methodology: Congenic model of DSS rat, fed with either high fat (HF) or normal (NF) diet, were used to demonstrate the impact of a chromosome segment from normotensive origin on physiological functions. C2SM9 contains GCA and sGC from normotensive origin while C2SM12 harbours only sGC from normotensive origin. Results: HF diet had negative feature on body composition, renal damage, creatinine clearance and inhibited the diuretic/natriuretic effect of ANP. The normotensive segment including GCA and sGC has reduced the blood pressure, improve the renal damage and increased the diuretic/natriuretic capacity of SM9 in response to ANP injection when compared to SM12 and DSS. GCA mRNA and the clearance receptor ratio were reduced in SM9 in the renal cortex and retroperitoneal fat. SM12 and SM9, containing the chromosomal segment that includes sGC, improve their lipid profile compared with DSS. Conclusion: Our results suggested a compensatory increase in the GCA levels for SM12 and DSS that is insufficient to improve their pathophysiologic status as observed in SM9. HF diet increases the metabolic syndrome in those rats.

Thèse réalisée dans le cadre d'une cotutelle entre l'Université de Montréal et l'Université d'Auvergne en France / Introduction De nombreuses études indiquent que la prématurité, qui représente 8 % des naissances, est associée à des indices précoces de dysfonction vasculaire, d’élévation de la pression sanguine et de survenue de diabète de type 2. Les enfants nés prématurément sont plus sujets aux blessures oxydatives de par l’immaturité de leurs défenses antioxydantes et de leur exposition à des situations pro-oxydantes (exposition à l’air ambiant, à un supplément d’oxygène, ou à une exposition aux infections). Cependant, les conséquences à long terme des blessures oxydatives induites par une exposition à l’oxygène en période périnatale restent méconnues. Le but de ce doctorat a été de mettre en évidence certains mécanismes pouvant relier les dommages de la prématurité induits par l’oxygène, et le risque à long terme de développer des maladies cardiovasculaires et métaboliques dans le concept global d’une programmation développementale de l’hypertension et des pathologies reliées au syndrome métabolique. Matériels et méthodes Des ratons Sprague-Dawley (SD) ont été exposés à 80 % O2 (O2) vs air ambiant (AA) du 3ème au 10ème jour de vie. Concernant les paramètres cardiovasculaires, nous avons mesuré au cours de la croissance, la pression sanguine à la queue (de la 4ème semaine à la 15ème semaine) et à l’âge adulte : la réactivité vasculaire à l’angiotensine II (AngII) et au carbachol (ex vivo, carotides) avec ou sans le tempol; la production d’oxyde nitrique (NO) en présence ou non L-arginine et de L-sépiaptérine (aorte, immunohistochimie) ainsi que l’expression de la nitric oxyde synthase endothéliale (eNOS) (aorte, immunohistochimie et western blot); le stress oxydant vasculaire (aorte, chemiluminescence) par la mesure de la production d’anions superoxide en présence ou non des inhibiteurs de la nicotinamide-adenine-dinucleotide-phosphate (NADPH oxydase) et de la nitric oxyde synthase endotheliale (eNOS), l’apocynine, et N-nitro-L-arginine methyl ester (L-NAME) respectivement, ainsi que le stress oxydant circulant par la mesure des niveaux plasmatiques de malondialdéhyde (MDA, HPLC); la densité microvasculaire a été évaluée au niveau du muscle tibial antérieur, immunohistochimie); la vitesse d’onde pulsée (VOP) (entre la valve aortique et juste avant la bifurcation ilio-fémorale) a été mesurée par ultrason; le nombre de néphrons a été compté par digestion acide. L’ontogenèse de la plupart de ces mécanismes a été regardée à l’âge de 4 semaines. Concernant les paramètres métaboliques, le poids a été mesuré au cours de la croissance. À l’âge adulte, la composition corporelle et la tolérance au glucose ont été évaluées. Résultats À l’âge de 4 semaines, aucune différence n’a été observée dans la pression sanguine, la réactivité vasculaire et le stress oxydant, mais chez les rats O2 vs AA, la densité microvasculaire est moindre, et des changements histologiques suggèrent la présence d’une rigidité artérielle augmentée. À l’âge adulte chez les rats O2 vs AA (n = 6-8 /groupe) : i) les pressions sanguines systoliques et diastoliques sont augmentées; ii) la réactivité vasculaire à l’AngII est augmentée et celle au carbachol est diminuée, le tempol prévient ces dysfonctions; iii) la production de NO est plus faible au niveau basal et après stimulation par le carbachol, mais est restaurée après la pré-incubation avec L-arginine et L-sépiaptérine; iv) l’expression d’eNOS est diminuée par immunohistochimie et augmentée par western blot; v) les niveaux d’anions superoxide, au niveau basal et en réponse à l’AngII, sont augmentés et sont induits par la NADPH oxydase et le non-couplage d’eNOS; vi) les niveaux plasmatiques de MDA sont augmentés; vii) La densité microvasculaire est moindre; viii) la VOP est augmentée; ix) le nombre de néphrons par rein est réduit; x) le poids est plus faible au cours de la croissance et un catch up est observé à l’âge adulte; la composition corporelle n’est pas différente entre les groupes; xi) la tolérance au glucose est diminuée. Conclusion Ces résultats supportent l’hypothèse d’une programmation développementale des maladies cardiovasculaires et métaboliques à l’âge adulte à la suite d’un stress hyperoxique néonatal. / Introduction Many studies showed that prematurity, which represents 8 % of birth, is associated with early indices of vascular dysfunction, increased blood pressure and Type 2 diabetes. Prematurity babies are more susceptible to oxidative injury, consequence of the immaturity of their antioxidant defences, and exposure to pro-oxidant situations (oxygen supplementation, infection). However, the long-term consequences of oxidative injury induced by oxygen exposure in the neonatal period are unknown. The aim of these PhD studies was to unravel some mechanisms that might underlie the damage induced by oxygen and the long-term risk of developing vascular and metabolic diseases in the overall concept of developmental programming of hypertension and metabolic syndrome-related diseases. Materials and methods Sprague-Dawley pups were kept with their mother in 80 % O2 (O2) or room air (RA) from day 3 to 10 of life. Cardiovascular parameters, tail blood pressure was measured between 4 and 15 weeks of life. In adulthood : vascular reactivity (ex vivo carotid rings) to angiotensine II (AngII) and carbachol with and without tempol was studied; studies of nitric oxide (NO) production with and without L-arginine and L-sépiaptérine (aorta, immunohistochemistry) and endothelial nitric oxide synthase expression (eNOS; aorta, immunohistochemistry, western blot) were performed; vascular oxidative stress (aorta, using chemiluminescence) by measuring superoxide anion production with and without inhibitors of nicotinamide-adenine-dinucleotide-phosphate (NADPH oxydase) and nitric oxyde synthase endotheliale (eNOS), apocynin and N-nitro-L-arginine methyl ester (L-NAME) respectively, and circulating oxidative stress by measuring the plasma levels of malondialdéhyde (MDA, HPLC) were evaluated; microvascular density was assessed on tibialis anterior muscle sections; pulse wave velocity (PWV) was measured by ultrasound, between aortic valve and ilio-femoral bifurcation; nephrons were counted after hydrochloric acid digestion. The main observations were also evaluated at 4 weeks of age. Metabolic parameters: body weight has been measured during the growth. In adulthood, body composition, glucose tolerance were evaluated. Results A 4 weeks of age, no difference was observed regarding blood pressure, vascular reactivity, and oxidative stress indices, but in rats O2 vs. RA (n = 6-8 /group), microvascular rarefaction and histological changes suggesting enhanced vascular stiffness were present. To adulthood, rats O2 vs. RA (n = 6-8/group) : i) systolic and diastolic blood pressures are increased; ii) vascular reactivity to Ang II is increased and to carbachol is decreased, these dysfunction were totally abolished by co-incubation of the vessel rings with tempol; iii) NO-production is decreased in basal condition and after carbachol stimulation, but is restored after pre-incubation of aorta sections with L- arginine and L-sépiaptérine; iv) eNOS expression is decreased by immunohistochemistry but increased by western blot; v) vascular superoxide anion levels are increased in basal condition, after AngII stimulation and this is mediated by NADPH oxydase and eNOS uncoupling; vi) the plasma levels of MDA are increased; vii) microvascular density is decreased; viii) PWV is increased; ix) nephron count per kidney is decreased; x) body weight is less during growth, but a catch up is observed in adulthood, body composition is similar; xi) the glucose tolerance is decreased in adults. Conclusion These results support the hypothesis of developmental programming of vascular and metabolic diseases in adulthood, after exposure to hyperoxic stress in the neonatal period.

The prevalence of childhood obesity and Type 2 Diabetes Mellitus (T2DM) has increased during recent decades. T2DM is accompanied with functional changes in the islets of Langerhans, which can be identified early in the pathogenesis. The aim of this thesis was to explore how metabolic changes caused by obesity early in life relate to islet function prior to overt T2DM. To address this, Uppsala Longitudinal Study of Childhood Obesity (ULSCO) was established (paper I). Initially, the association between palmitate and insulin secretion was investigated using a translational approach with obese and lean normoglycemic juveniles and isolated human islets (paper II). Secondly, dynamics of islet-hormones insulin and glucagon, and gut-hormones glucagon like-peptide 1 (GLP-1) and glicentin (paper III) and magnetic resonance imaging of pancreatic fat fraction (PFF) (paper IV) were studied in association to glucose tolerance and beta-cell function. Finally, a novel method of analysing shape features of oral glucose tolerance test (OGTT) curves was introduced and evaluated (paper V). Obese subjects had high prevalence of prediabetes and metabolic syndrome (MetS) (paper I). In obese pre-pubertal children with elevated palmitate levels, hyperinsulinemia was observed (paper II). In contrast, obese pubertal adolescents with similar palmitate levels showed moderate insulin levels during OGTT with delayed first phase insulin response. To explore mechanisms for these variations, isolated human islets were exposed to palmitate for different time periods in vitro. After 2 days accentuated insulin response was observed. Impaired beta-cell function and apoptosis were evident after 7 days, however. Hyperglucagonemia and disturbed GLP-1 and glicentin levels were associated with obesity and glycaemic status, with fasting glicentin being predictive of prediabetes (paper III). Furthermore, PFF was increased in obese subjects and associated to MetS and visceral adipose tissue, but not to beta-cell function (paper IV). OGTT curves were converted into geometric centres, centroids, which correlated with differences in glucose tolerance (paper V). In conclusion, the islet function in obese children was associated with elevated levels of palmitate, but not pancreatic fat. Fasting palmitate and glicentin levels, as well as centroid analyses of OGTT curves, could potentially identify obese children at risk of prediabetes and subsequent T2DM.

Les antipsychotiques de deuxième génération (ADG) sont de plus en plus employés dans le traitement de troubles psychiatriques. Selon de nombreuses observations cliniques, les effets secondaires reliés à la prise d’ADG diffèrent chez les patients atteints de schizophrénie (SCZ) et de maladies affectives (MA) éprouvent divers. Ainsi, il s’avère nécessaire d’étudier la fréquence et l'intensité des effets secondaires induits par les ADG qui pourraient différer selon le diagnostic. Pour ce faire, nous avons effectué une revue systématique de la littérature afin d’identifier l’ensemble des études rapportant les effets secondaires de cinq ADG (aripiprazole, olanzapine, quétiapine, rispéridone et ziprasidone) dans le traitement de la schizophrénie ou des maladies affectives. Les effets secondaires métaboliques et extrapyramidaux ont été recueillis séparément pour les deux groupes de patients, puis ont été combinés dans une méta-analyse. Des méta-régressions ainsi que des sous-analyses ont également été effectuées dans le but de regarder l’effet de différents modérateurs (i.e. âge, genre, et dose). Dans la présente méta-analyse, 107 études ont été inclues. Les résultats montrent que le traitement avec l’olanzapine a occasionné une plus importante prise de poids chez les patients SCZ comparativement aux patients MA. De plus, le traitement à la quétiapine a amené une hausse significative du taux de LDL et de cholestérol total dans le groupe SCZ par rapport au groupe MA. Selon nos résultats, les symptômes extrapyramidaux étaient plus fréquents dans le groupe MA, excepté pour le traitement à l'olanzapine qui a induit davantage de ces symptômes chez les patients SCZ. Également, nos résultats suggèrent que les patients SCZ seraient plus vulnérables à certains effets métaboliques induits par les ADG dû à une possible susceptibilité génétique ou à la présence de facteurs de risque associés au style de vie. D'autre part, les patients MA en comparaison aux SCZ étaient plus enclins à souffrir de troubles du mouvement induits par les ADG. Bref, les ADG semblent exacerber certains types d’effets secondaires tout dépendant de la maladie dans laquelle on les utilise. / Second generation antipsychotics (SGAs) are extensively prescribed for psychiatric disorders. Based on clinical observations, schizophrenia (SCZ) and affective disorders (AD) patients experience different SGAs side effects. The expanded use of SGAs in psychiatry suggests a need to investigate whether there is a difference in the incidence and severity of side-effects related to diagnosis. A comprehensive literature search was conducted to identify studies reporting side effects of five SGAs (aripiprazole, olanzapine, quetiapine, risperidone and ziprasidone) in the treatment of SCZ or AD. The metabolic and extrapyramidal side effects were collected separately for each group, and then were combined in a meta-analysis. Meta-regression and sub-analyses were also performed to investigate the role of different moderators (e.g., age, dose and gender). One hundred and seven studies were included in the analysis. Olanzapine induced a body weight gain significantly higher in SCZ patients than in AD patients. In addition, quetiapine treatment led to significantly higher LDL and total cholesterol mean change in the SCZ group relative to the AD group. Based on our results, the incidence of extrapyramidal side effects was more frequent in the AD group, except for olanzapine that caused more parkinsonism in SCZ patients. Our results suggest that SCZ patients may be more vulnerable to some SGA-induced metabolic disturbances, in which lifestyle risk factors and a possible inherent genetic vulnerability may play a role. Most of the studied SGAs caused more movement disorders in AD patients than in schizophrenics. It might be that an antipsychotic induces severity of side effect according to the phenotype.