Hypertension artérielle résistante et maladie rénale chronique : Déterminants et risques associésL’hypertension résistante, définie par une pression artérielle au-dessus de la cible en dépit de la prise de trois antihypertenseurs à dose optimale dont un diurétique, est fréquemment associée à la maladie rénale chronique (MRC). Sa prévalence, ses déterminants et l’impact potentiel de la MRC sur son pronostic à long terme sont mal connus, notamment chez le sujet âgé. Dans l’étude des 3 cités, incluant 4262 personnes de plus de 65 ans traitées pour hypertension, la prévalence de l’hypertension apparemment résistante (HTAR) - la notion de traitement à dose optimale étant inconnue - était de 11,8% vs 5,2% chez ceux avec vs sans MRC (définie par une fonction rénale < 60 mL/min/1.73 m2). Nous avons montré que l’apparition d’une HTAR était plus fortement liée à la rapidité du déclin annuel de la fonction rénale qu’à son niveau, indépendamment des autres facteurs de risque : obésité, diabète, sexe masculin, antécédent cardiovasculaire. Comparé au groupe de référence (avec hypertension contrôlée et sans MRC), les personnes avec une HTAR et une MRC n’avaient pas de risque significativement plus élevé de mortalité toute cause, mais avaient deux fois plus de risque d’accident vasculaire cérébral (AVC), létal ou non, et de récurrence d’un AVC ou d’un événement coronaire, et trois fois plus de décès coronaire. Cependant, l’’hypothèse d’un effet aggravant de la MRC sur le pronostic de l’HTAR n’a pas été confirmé (interaction non significative).Dans la cohorte CKD-REIN, incluant plus de 3000 patients avec une MRC modérée ou avancée suivis en néphrologie (âge moyen, 70 ans, 60% d’hommes), nos résultats préliminaires montrent une prévalence élevée d’HTAR, 36,7%, et plusieurs facteurs de risque potentiellement modifiables : adhérence médiocre au traitement, absence de diurétique, consommation de sel en excès, obésité.Dans l’ensemble, ces travaux montrent l’importance de la MRC dans le développement de l’HTAR et des risques cardiovasculaires associés, et suggère des moyens de prévention au-delà des traitements médicamenteux. / Resistant hypertension and chronic kidney disease: Determinants and outcomesResistant hypertension defined as blood pressure above goal despite simultaneous use of 3 antihypertensive classes at optimal doses including a diuretic, is commonly associated with chronic kidney disease (CKD). Resistant hypertension prevalence and determinants, and the impact of CKD on its long term outcomes are poorly known, particularly in the elderly population.In the 3 Cities cohort, including 4262 community-dwelling elderly individuals, aged 65 years or older treated for hypertension, the prevalence of apparent treatment resistant hypertension (aTRH) – because of lack of information on optimal treatment dose – was 11.8% vs 5.2% in those with vs without CKD (defined as estimated glomerular filtration rate < 60 mL/min/1.73 m2). We showed that new-onset aTRH was more strongly related to the speed of kidney function decline than kidney function level itself, independent of other risk factors: male sex, obesity, diabetes, and history of cardiovascular disease. Compared to the reference group (with controlled hypertension and no CKD), participants with aTRH and CKD had no significantly higher risk of all-cause mortality, but had a risk of fatal or non-fatal stroke and of recurrent stroke or coronary events more than twice as high, and of coronary death more than three times higher. However, the hypothesis that CKD may worsen the prognosis of aTRH was not confirmed (no significant interaction).In the CKDREIN cohort, which included more than 3000 nephrology outpatients with moderate or severe CKD (mean age, 70 years, 60% of men), our preliminary results showed a high prevalence of aTRH, 36,7% and several potentially modifiable risk factors : poor treatment adherence, lack of diuretic use, excess salt intake and obesity.Overall, this work shows the importance of CKD in the development of aTRH and associated cardiovascular outcomes, and suggests means for prevention beyond drug therapy.

Il termine malattia renale cronica (Chronic Kideny Disease: CKD) si riferisce a differenti condizioni caratterizzate da un progressivo declino della funzione renale. Le linee guida internazionali hanno definito la CKD come una condizione in cui siano presenti marcatori di danno renale e/o la velocità di filtrazione glomerulare stimata (Estimated Glomerular Filtration Rtae: eGFR) sia inferiore a 60 ml/min/1.73 m2 per almeno 3 mesi. L’insufficienza renale in stadio terminale è associata ad un alto rischio di malattia cardiovascolare (Cardiovascular Disease: CVD), la più frequente causa di morte in questi pazienti. Fattori di rischio “non-tradizionali” come: infiammazione cronica, stress ossidativo, deplezione proteico-energetica, disordini del metabolismo minerale e deficit di inibitori della calcificazione, partecipano alla patogenesi della CVD. L’infiammazione gioca un ruolo cruciale nella risposta fisiologica all’infezione e al danno renale e partecipa anche nell’evoluzione del danno renale irreversibile con la produzione di diverse molecole infiammatorie a partire da acidi grassi polinsaturi a lunga catena (Long Chain PolyuUsaturated Fatty Acids: LCPUFA) della serie Omega-6. La supplementazione di Omega-3, con effetto antinfiammatorio, nei pazienti affetti da CKD è stata ed è oggetto di molti studi, nonostante ciò, l’effetto sul danno renale è ancora poco chiaro. Comunque, è ampiamente riconosciuto che un alterato profilo lipidico possa determinare la progressione della patologia, inducendo lo stato infiammatorio. Inoltre, elevati/normali livelli di Omega-3 potrebbero essere associati al miglioramento della funzionalità renale, diminuendo quindi il rischio di peggioramento della malattia. Le concentrazioni e il rapporto di Omega-3 e Omega-6 sono strettamente associati alla salute del rene, poiché svolgono ruoli importanti in differenti vie metaboliche. Un altro aspetto, preso poco in considerazione, è l’effetto dei livelli di acidi grassi circolanti e dei loro metaboliti sullo stato infiammatorio e sulla sua modulazione. Il primo scopo di questo studio è stato quello di analizzare il profilo degli acidi grassi in soggetti anziani affetti da CKD. Sono stati arruolati 57 pazienti afferenti agli ambulatori di Nefrologia dell’Ospedale Maggiore Policlinico di Milano e sono stati raccolti campioni di sangue su cui è stata effettuata l’analisi del profilo lipidico. Negli ultimi anni, diversi studi hanno sottolineato la stretta associazione tra infiammazione a livello intestinale e peggioramento del quadro in pazienti con CKD. Il mantenimento di un ottimo stato del tratto gastrointestinale è fondamentale per assicurare lo stato di salute dell’ospite, contribuendo ai processi metabolici, fisiologici e immunologici. Le comunità batteriche instaurano un rapporto mutualistico con l’individuo che colonizzano, giocando un ruolo importante negli stati di salute e malattia. Un’anomala colonizzazione o cambiamenti nella composizione del microbiota intestinale, determina disbiosi, uno squilibrio associato a diverse condizioni patologiche come obesità, diabete di tipo II, malattia intestinale cronica, CVD e anche CKD. Il rapporto tra intestino e rene è bidirezionale, nei pazienti affetti da malattia renale cronica, la composizione del microbiota intestinale risulta essere modificata rispetto a quella del soggetto sano. Alti livelli di urea che si riversano facilmente nel tratto intestinale modificano il microambiente chimico con conseguente innalzamento del pH del colon che esercita una pressione selettiva a favore di specie ureasi-positive, responsabili della conversione dell’urea in ammoniaca. Lo strato protettivo di muco viene degradato e la permeabilità della barriera intestinale viene compromessa. In conseguenza di ciò si ha il passaggio di materiale batterico attraverso la mucosa e l’attivazione di un meccanismo infiammatorio. Nei pazienti con funzionalità renale compromessa, il rene perde progressivamente la capacità di eliminare sia le sostanze provenienti dal metabolismo umano, sia quelle della comunità microbica intestinale. Alcune di queste sostanze sono rappresentate dalle tossine uremiche, tra quelle di derivazione intestinale le principali e più studiate sono p-cresil solfato (PCS) e indossile solfato (IS). IS e p-CS, strettamente legate all’albumina sierica (Human Serum Albumin: HSA), non vengono eliminate facilmente ma rimangono nel torrente ematico. HSA è la più abbondante proteina sierica ed è la principale trasportatrice di composti esogeni ed endogeni, inclusi gli acidi grassi che sembrano rappresentare il maggior ligando endogeno della proteina. Multipli siti di legame vengono utilizzati per gli acidi grassi monoinsaturi (MonoUnsaturated Fatty Acids: MUFA) e PUFA. Acidi grassi e tossine uremiche competono quindi per gli stessi siti di legame sulla proteina. Il potenziale ruolo degli acidi grassi nel contrastare l’accumulo di tossine uremiche derivate dalla comunità batterica intestinale ne giustifica l’importanza della valutazione dei loro livelli ematici. Secondo scopo di questa tesi di dottorato è stato quello di valutare la possibile correlazione tra i livelli di acidi grassi circolanti e la composizione del microbiota intestinale in soggetti affetti da CKD. Sono stati arruolati nello studio 64 pazienti anziani con CKD non dializzati e 15 soggetti anziani con normale funzionalità renale. La composizione del microbiota intestinale è stata precedentemente caratterizzata attraverso l’impiego delle tecniche di elezione: PCR-DGGE e la PCR quantitativa (qPCR). In accordo con la letteratura scientifica, è stata evidenziata una riduzione di batteri saccarolitici e produttori di butirrato nei pazienti con CKD rispetto al gruppo di controllo. Il butirrato sembra giocare un ruolo cruciale nel mantenimento delle ottimali condizioni della barriera intestinale. Tenendo ciò in considerazione è stato deciso di approfondire lo studio e valutare l’associazione tra la comunità microbica intestinale e i livelli di acidi grassi basali in tali pazienti. Come risultato più importante ottenuto, è stata osservata una correlazione positiva statisticamente significativa tra la specie batterica Faecalibacterium Prausnitzii e i livelli totali di Omega-3 entrambi associati a proprietà antinfiammatorie. La presente tesi di dottorato evidenzia la necessità di sostenere ulteriori ricerche per supportare i risultati qui presentati. Studi futuri potrebbero essere utili per migliorare la comprensione del ruolo degli acidi grassi circolanti e i loro metaboliti sulla composizione del microbiota intestinale, sullo stato infiammatorio e sulla malattia renale cronica. / The aim of this thesis was to explore the possible associations between fatty acids (FA) profile and gut microbiota (gMb) with several conditions throughout the lifespan, from infancy to old age. In particular, we focused our attention on elderly subjects with Chronic Kidney Disease (CKD) and children with Acute Otitis Media (AOM). The terms “Chronic Kidney Disease” refers to several disorders with a progressive kidney function decline. International guidelines approved the definition of CKD as a condition with the presence of markers of kidney damage or with the estimated glomerular filtration rate (eGFR) less than 60 ml/min/1.73 m2 or both, for at least three months. End-stage renal disease is associated with a high cardiovascular disease (CVD) risk, the major cause of death in these patients. Chronic inflammation, oxidative stress, protein-energy wasting, disordered mineral metabolism, and deficiency of endogenous calcification inhibitors, known as non-traditional risks factor, take part in cardiovascular pathology in CKD. Inflammatory processes influence the physiological response to renal infection and injury but also participate in the development of potentially irreversible kidney damage with the production of various inflammatory molecular species, among whom eicosanoids and cytokines, from parental omega-6 long-chain polyunsaturated fatty acids (LCPUFA). Several studies focused their attention on the potential role of omega-3 (n-3) LCPUFA supplementation in subjects with CKD. Despite this, their effect on kidney damage is still not clear. However, it is widely agreed that a modified FA profile in CKD can determine a progression of the disease, inducing the inflammatory state. Moreover, high/normal n-3 LCPUFA levels decrease the risk of a decline of the disease. Omega-3 and omega-6 (n-6) LCPUFA concentrations and their ratios are tightly associated with renal health, because of their important roles in different pathways. Another aspect not very considered in the field of CKD is the role of circulating FA levels and their metabolites on the modulation of inflammation. The first aim of this study is to analyze the FA profile in elderly subjects with CKD. Blood samples have been collected from 57 subjects enrolled in the study, and FA analysis has been performed. During the last years, several studies underlined the strong relationship between intestinal inflammation and adverse outcomes in CKD. The health of gastrointestinal tract is fundamental to ensure the well being of the host contributing to its nutrition, metabolism, physiology, and immune function. The bacterial communities colonizing humans have been seen in terms of mutualistic symbiosis with their hosts, a mutually beneficial coexistence, playing an important role in health and disease. Abnormal colonization or changes in the gut microbial composition determine dysbiosis, a state associated with different illnesses, such as obesity, type 2 diabetes, inflammatory bowel disease, cardiovascular disease, and also chronic kidney disease. The relationship between gut and kidney is a bi-directional relation with a mutual influence. Chronic kidney disease influences gMB characteristics, especially through high levels of urea that easily spread in the intestinal fluid where bacterial urease enzymes degrade it, then it is hydrolyzed in ammonium hydroxide that increases fecal pH with a consequent alteration of intestinal cellular junctions. Besides, high levels of urea change intestinal microbiota composition damaging permeability of intestinal barrier and promoting proteolysis with production and absorption of uremic toxins, such as indoxyl sulfate (IS) and p-cresol sulfate (p-CS). These toxins induce an inflammatory process associated with CKD. Under physiologic conditions, the kidney through the urine eliminates these compounds, but CKD patients have a compromised renal clearance. Therefore, these solutes tend to accumulate in the organs. IS and p-CS are tightly bound to human serum albumin (HSA), the most abundant plasma protein in the bloodstream. HSA is recognized as the main means of transport for endogenous and exogenous compounds, including fatty acids that seem to be the main endogenous ligand of HSA, multiple binding sites are used for monounsaturated fatty acids (MUFA) and PUFA. Thus, free fatty acids and uremic toxins compete for the same binding sites on HSA. It is important to assess fatty acid (FA) levels in patients with CKD because of the potential role to contrast the accumulation of uremic toxins derived from the intestinal bacterial community. As a consequence of this bi-directional relation between gut and kidney and the possible involvement of some compounds as metabolites of FA in the inflammatory response, we investigate the correlation between circulating FA levels and the gMB composition in the same subjects with CKD, as the second aim of this thesis. 64 old CKD non-dialysis patients (eGFR 15-45 ml/min/1.73 m2) and 15 elderly subjects (>65 years) with normal renal function (eGFR >60 ml/min/1.73 m2, CKD-EPI) are enrolled. Bacterial composition was studied in a previous observational study by denaturating gel gradient electrophoresis (DGGE), high-throughput sequencing (16S ribosomal RNA), and quantitative real-time PCR (qPCR). This study described an increased abundance of some bacteria associated with pathological conditions. In agreement with the literature, the author found a reduced abundance of saccharolytic and butyrate-producing bacteria (Prevotella, Faecalibacterium prausnitzii, Roseburia) in CKD patients respect to the control group. Butyrate plays a crucial role in the maintenance of the gut barrier function. Taking that into account, we decided to investigate the correlation between gMB composition and FA profile in these subjects. The main result of the study was the significant positive correlation between Faecalibacterium prausnitzii and total n-3 levels, both associated with the antiinflammatory action. The present doctoral thesis underlines the need to perform further investigations in order to support evidence presented. Future studies may be useful to improve understanding of the effect of circulating fatty acids levels and their metabolites on gut microbial composition, inflammation process, and pathological conditions such as kidney disease. Our results showed that CKD patients with previous cardiovascular events had lower total and specific n-3 levels comparing with patients without them. Moreover, higher docosahexaenoic acid (DHA) levels and having had previous cardiovascular events seemed to have protective effects against further cardiovascular events. Moreover, we observed a significant reduction of the genera Roseburia and Faecalibacterium in CKD patients compared to C group and a significant lower abundance of F. prausnitzii and Roseburia spp. in CKD patients. Thus, our results seem in accordance with anti-inflammatory actions of total n-3, DHA, and saccharolytic and butyrateproducing bacteria. Many gMB changes seem to be related both to CKD and CVD. If the different gMB composition might play a causal role in cardiovascular events by an unbalanced production of some toxic substances, or if the gMB changes are merely a consequence of different dietary and lifestyle behaviours of these patients, it cannot be explained by the present study and all the yet available data. Further studies, possibly utilizing new high-throughput tools, will be required to understand the potential correlations between the gMB composition and other inflammation and oxidative stress markers in these patients. Other two studies have been performed during the doctoral course, to reach a better comprehension of fatty acids, gut microbial community and inflammatory states. A prospective pilot clinical study has been performed to to explore possible changes of gMB composition in children with AOM treated with amoxicillin with or without clavulanic acid. AOM is one of the most common bacterial infections in children and is normally treated with antibiotic therapies that lead to increasing antimicrobial resistance rates among otopathogens and may impair the correct development of the microbiota in early life. No significant differences were shown in the gMB composition of the overall cohort at different time intervals of the samples collection and in subjects treated with amoxicillin with or without clavulanic acid at different time intervals (T0, T1 and T2). A literature revision on lipids in infant formulae has been performed to better understanding quality and quality of dietary lipids because of their significant impact on health outcomes, especially when fat storing and/or absorption are limited (e.g., preterm birth and short bowel disease) or when fat byproducts may help to prevent some pathologies. The lipid composition of infant formulae varies according to the different fat sources used, and the potential biological effects are related to the variety of saturated and unsaturated FAs. Instead, ruminant-derived trans FAs and metabolites of n-3 LCPUFA with their anti-inflammatory properties can modulate immune function. Furthermore, dietary fats may influence the nutrient profile of formulae, improving the acceptance of these products and the compliance with dietary schedules. During the doctoral course, I spent a period abroad at Dell Pediatric Research Institute (DPRI), The University of Texas at Austin. In particular, I attended the laboratory of Doctor Brenna. I focused my research activity on a specific regulatory insertion-deletion polymorphism in the FADS gene cluster for better understanding its influence on PUFA and lipid profile.

La glycogénose de type Ia (GSDIa) est une maladie métabolique rare causée par une déficience en glucose-6-phosphatase (G6Pase), due à des mutations de la sous-unité catalytique (G6PC). Cette enzyme confère au foie, aux reins et à l’intestin la capacité de produire du glucose. Les patients atteints de GSDIa sont donc incapables de produire du glucose et souffrent d’hypoglycémies sévères lors de jeûnes courts. De plus, la déficience en G6Pase provoque une accumulation de glucose-6 phosphate dans le foie et les reins, conduisant à l’accumulation de glycogène et de lipides. A long terme, la plupart des patients souffre d’une maladie chronique rénale (MCR), qui peut évoluer en insuffisance rénale, nécessitant une mise sous dialyse ou une transplantation rénale. Cette MCR se caractérise par une fibrose, ainsi que par le développement de kystes dans les stades tardifs. Au niveau du foie, les patients développent une hépatomégalie et une stéatose hépatique qui peut évoluer vers le développement d’adénomes ou carcinomes hépatocellulaires. Le but de mes travaux de thèse a été d’identifier les mécanismes moléculaires impliqués dans l’établissement de la pathologie rénale et la formation des kystes, à l’aide de modèles murins invalidés pour le gène G6pc spécifiquement dans les reins (souris K.G6pc-/-). Alors que la GSDIa est une maladie caractérisée par l’accumulation hépatique et rénale de glycogène, nous avons d’abord montré que le développement de la fibrose, à l’origine de la perte de la fonction rénale, était induit par l’accumulation de lipides, indépendamment du contenu en glycogène. De plus, l’utilisation d’un agoniste de PPARα, le fénofibrate, en diminuant le contenu lipidique rénal, a ralenti l’installation de la fibrose et l’évolution de la MCR. Le mécanisme moléculaire impliqué est l’activation du système rénine angiotensine par les dérivés lipidiques, qui induit l’expression du facteur profibrotique TGFβ1. De même, le fénofibrate en limitant l’accumulation de lipides hépatiques a prévenu le développement d’atteintes hépatiques caractéristiques de la GSDI. Ainsi, l’activation du catabolisme des lipides par des agonistes de PPARα semble une stratégie thérapeutique intéressante pour réduire la progression des maladies rénales et hépatique de la GSDI. La deuxième partie de mes résultats suggèrent que le développement de kystes rénaux chez les patients atteints de la GSDI pourrait être causé par une altération du cil primaire, organelle jouant un rôle clé dans le maintien d’une structure et fonction normale des reins. En effet, une augmentation de la longueur du cil primaire a pu être observée dans les reins des souris K.G6pc-/- associée à une dérégulation de différentes protéines impliquées dans sa structure et sa fonction, par rapport aux souris contrôles. Nous avons également mis en évidence une reprogrammation métabolique de type Warburg, caractérisée par une activation accrue de la glycolyse aérobie, une inhibition de l’oxydation mitochondriale du pyruvate et une production de lipides. Ainsi, l’ensemble de ces perturbations va favoriser la prolifération cellulaire et le développement de kystes, et pourrait mener au développement de tumeur rénale comme observée chez une souris K.G6pc-/-. En conclusion nous avons démontré que, dans le cadre de la GSDI, l’accumulation de lipides dans les reins et le foie, secondaire à la déficience en G6Pase, joue un rôle clé dans le développement des complications hépatiques et rénales à long terme. Également, la reprogrammation métabolique rénale de type Warburg, prenant place dans le cadre de la GSDI, associée à un défaut du cil primaire pourrait être à l’origine de la formation des kystes et de tumeurs rénales. Ces études, en permettant une meilleure compréhension de la physiopathologie des complications à long terme de la GSDIa, offrent de nouvelles perspectives concernant les stratégies thérapeutiques à développer pour une meilleure prise en charge des patients atteints de GSDIa / Glycogen storage disease type Ia (GSDIa) is a rare metabolic disease caused by glucose-6-phosphatase (G6Pase) deficiency, due to mutations on the gene encoding G6Pase catalytic subunit (G6PC). This enzyme confers to the liver, kidneys and intestine the ability to produce glucose. Thus, patients with GSDIa are unable to ensure endogenous glucose production and suffer from severe hypoglycemia during fasting in the absence of nutritional control. In addition, G6Pase deficiency causes intracellular accumulation of glucose-6 phosphate in the liver and kidneys, leading to metabolic defects and the accumulation of glycogen and lipids. Over time, most adult patients suffer from chronic kidney disease (CKD), which can progress to kidney failure, requiring dialysis or kidney transplantation. This nephropathy is characterized in particular by tubulo-interstitial fibrosis and glomerulosclerosis, as well as by the development of cysts in the late stages. Moreover, patients develop hepatomegaly and hepatic steatosis that may progress to the development of hepatocellular adenomas or carcinomas. The aim of my thesis was to identify the molecular mechanisms involved in the establishment of renal pathology and cyst formation in GSDIa, by using mouse models where G6pc gene is specifically deleted in the kidneys (K.G6pc-/- mice). While GSDIa is a disease characterized by glycogen accumulation in the liver and kidneys, we first showed that the development of fibrosis, which causes progressive loss of kidney function, was induced by intracellular accumulation of lipids, regardless of glycogen content. The molecular mechanism probably involved is the activation of the renin angiotensin system by lipid derivatives such as diacylglycerol, which induced the expression of the profibrotic factor TGFβ1 and an epithelial-mesenchymal transition. In addition, the use of a PPARα agonist, i.e. fenofibrate, by decreasing renal lipid content, reduced the development of fibrosis and CKD evolution. Similarly, fenofibrate treatment prevented the accumulation of lipids in the liver and the development of liver damages that cause tumor development. Thus, the activation of lipid catabolism by PPARα agonists such as fenofibrate seems to be an interesting therapeutic strategy to reduce the progression of renal and hepatic diseases of GSDIa. The second part of my results suggest that the development of renal cysts in GSDI patients may be caused by an alteration of the primary cilia, a non-motile organelle that plays a key role in maintaining normal kidney structure and function. Indeed, defects in the primary cilia are involved in many polycystic kidney diseases. In summary, an increase in the length of the primary cilia was observed in the kidneys of K.G6pc-/- mice, which could be explained by a deregulation of the expression of different proteins involved in cilia structure and function, compared to control mice. We also demonstrated a metabolic reprogramming leading to a Warburg metabolism, characterized by the increased activation of aerobic glycolysis and the inhibition of mitochondrial pyruvate oxidation and lipid production in K.G6pc-/- mice. Thus, all these disorders would promote cell proliferation and cyst development, and could lead to the development of renal tumor, as recently observed in one K.G6pc-/- mouse (out of 36 studied mice). In conclusion, we have shown that, in GSDI, the accumulation of lipids in the kidneys and liver that occurs secondary to G6Pase deficiency plays a key role in the development of hepatic and renal long-term complications. In addition, the Warburg like metabolic reprogramming taking place in the GSDIa kidneys, associated with a defect in the primary cilia, could be at the origin of cysts formation and renal tumors. These new studies, by providing a better understanding of the pathophysiology of long-term complications of GSDIa, offer new perspectives on therapeutic strategies to be developed for better management of patients

Les omégas trois ont un bénéfice prouvé dans la prévention de maladie cardiovasculaire et l’inflammation. Un apport optimal peut être réalisé avec des modifications diététiques simples permettant d’avoir un enrichissement des membranes cellulaires et un effet métabolique. Le tissu adipeux de part son rôle important dans la genèse du syndrome métabolique semble être une cible importante du traitement par oméga trois. Les patients avec une maladie rénale chronique (MRC) ont un risque cardiovasculaire accru et cumulent les perturbations métaboliques comme le syndrome métabolique et un état micro inflammatoire. Des doses supra physiologiques d’oméga trois ont été utilisés dans le passé dans des études de prévention rénale ou traitement de dyslipidémie. Or l’effet métabolique en fonction de la dose d’oméga 3 n’est pas connu. En accord, avec les études chez le sujet sain, en fonction de la dose administrée, les omégas 3 ont un impact différent métabolique et sur l’expression génique. Des études complémentaires sont nécessaires pour vérifier la faisabilité et l’impact métabolique d’une modification de régime afin de diminuer le rapport n-6/n-3, ainsi que l’effet à long terme des omégas trois chez ces patients. Par ailleurs, les mécanismes impliqués dans les différences de dose réponse devront être caractérisés sur un modèle animal / Omega 3 fatty acids play an important modulatory role in metabolic and inflammatory responses, the progression of atherosclerosis and gene expression. Recent studies suggest their beneficial impact on adipocyte morphology and function. Chronic kidney disease (CKD) patients have an increased cardiovascular morbi-mortality and suffer from a cluster of metabolic disorders. On the basis of previous studies there are reasons to suggest that omega 3 supplementation may offer a host of benefits to CKD patients. Unfortunatly, published studies on the effect of such supplementation are characterized by supra physiological omega 3 doses, that may be difficult to implement for extended periods in one hand and in the other hand the metabolic effect of different doses of omega 3 hasn’t been studied in detail. Simple dietary modifications can help achieve the recommended n-6/n-3 ratio in healthy subjects. In CKD patients supplementation with n-3 shows a differential dose response effect. Further studies are required to test the faisability and metabolic impact of dietary modifications in order to decrease n-6/n-3 ratio and to assess the long term effect of omega supplementation in CKD patients. Finally the molecular pathways implicated in this differential dose response should be assessed in animal models

and key words Enhanced activation of renin-angiotensin system (RAS) and endothelin system (ES) plays the key pathophysiological role in the progression of hypertension and the chronic kidney disease (CKD). The aim of this study was to verify wheter the combined inhibition RAS and selective inhibition ETA receptor for endothelin 1 (ET-1) will show additive renoprotective effects in experimental model CKD. This therapeutic aproach was tested on the transgenic rats with mouse renin gen (TGR), to whome ablation nephrectomy (5/6 NX) was done in the age of 6 weeks. After next 6 weeks the relevant treatment was given in drinking-water: dual RAS blockade (trandolapril 6mg/L + losartan 100mg/L) or the combination of dual RAS blockade + inhibitor of ETA receptor (atrasentan 25mg/L). Results of the first series show 100 % mortality in untreated rats with 5/6 NX to the 30th week. Both type of treatments increased the survival rate up to 30 % in 5/6 NX TGR after the 50th week. In the second series influence of treatments on the blood pressure (BP) was monitored in 5/6 NX TGR, which had systolic BP over 210 mmHg. Both treatments decreased BP to the level normotensive rats and reduced heart hypertrophy. In the third series the results showed that treatment significantly decreased renal level of angiotensin II...

An increase in cellular inflammatory biomarkers directly increases the risk of cardiovascular disease (CVD). Using the social ecological and biomedical theories, the study examined quantitatively how specific inflammatory biomarkers are associated with cardiorenal syndrome (CRS), a potential complication of hypertension and diabetes, and how sociodemographic factors modify this association in the U.S. adult population. A retrospective secondary data analysis of the data collected from National Health and Nutrition Examination Survey (NHANES) 1999-2010 was utilized to evaluate these hypotheses. High sensitivity C-reactive protein, homocysteine (hcy), and fibrinogen had a modifying effect on Type 4 (chronic reno-cardiac etiology), Type 2 CRS (chronic cardio-renal etiology), and a significant additive effect on CRS even after controlling for known CVD and Chronic Kidney Disease (CKD) risk factors. For Type 4 CRS, the adjusted Odds Ratio of CVD in individuals with CKD was elevated, 2.29 (Confidence Interval [CI] 1.17-3.64, p < 0.05), among individuals with elevated hcy levels but close to 1.0 (0.65 CI 0.28-1.53, p > 0.05) among patients with normal hcy after the results were controlled for medical and demographic risk factors. Finally, race modified the effect of inflammatory markers on CRS. Out of all the biomarkers, income only modified the effect of hcy on CRS. Education level modified the effect of every inflammatory marker on CRS. While Ferritin-to-Transferrin ratio (F/T ratio) had a non-significant additive effect, due to the lack of adequate subjects, the modifying effect of F/T ratio could not be tested. This study can help initiate social change by urging healthcare professionals to monitor these biomarkers as a part of preventing hypertension, diabetes, and CRS.

Health literacy is widespread, but its potential is not recognized. By not recognizing health literacy, patients have the burden of coping with diabetes with renal complications without full knowledge of their responsibility to their health. The focus of the project was to assess participants with diabetes with low health literacy and low mean glomerular filtration rate (eGFR). The project goal was achieved by the assessment of the participants' health literacy and eGFR before and after education for their diabetes, then assessed to determine if teaching the participants would improve their health literacy, lab values, and overall health. Participants were recruited by being patients of the designated clinic and screened for diabetes and low eGFR, for a total of 30 participants. The Brief Health Literacy Screen was used to measure health literacy. The health of the participants was appraised by the laboratory values of eGFR and fasting glucose. The project methodology was an observational design using correlation and 2-sample t analysis with the variables eGFR, fasting glucose, and health literacy. The variables were compared before and after the participants' education. Results showed health literacy with patient education was associated with greater patient self-efficacy and improved fasting glucose numbers, eGFR flows, and health literacy scores. The current health climate shows value in different types of health providers. Social change was defined by the project launching a nurse practitioner as the leader for advancing the treatment plans of chronic kidney disease. This project impacts social change by showing patients in the process of improved health and empowering the patients to be advocates of their own health.

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第19599号 / 医博第4106号 / 新制||医||1014(附属図書館) / 32635 / 京都大学大学院医学研究科医学専攻 / (主査)教授 柳田 素子, 教授 妹尾 浩, 教授 浅野 雅秀 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

Chronic Kidney Disease (CKD) is a common and dangerous health condition that requires early detection and treatment to be effective. Current diagnostic methods are time-consuming and expensive. In this research, we hope to construct a predictive model for CKD utilizing a combination of time series and static variables for early detection of CKD. In this study, we investigate the influence of multimodal approach by combining the predictions from multiple models that utilize different modalities. The ROCKET method is utilized for classification using time series features, whilst the Random Forest approach is employed for static data. XGBoost has been utilized to gain information about feature importance among labs and demographics-comorbidities data. In this study, we use the MIMIC-III database, adopting various strategies to handle data and class imbalance, such as stratification, balancing techniques, and backwards and forward fill for missing value imputation. The evaluation metrics for CKD and non-CKD class labels include precision, recall, F1, and accuracy. Our findings show that aggregating time series data produce contrasting results for labs compared to vitals data. We also addressed the significance of the different demographic, comorbidities and lab events features. The findings indicate that a multimodal approach did not show significant advantages over individual models when the individual models performed suboptimal. The study also found that Ethnicity is more significant than age and gender in predicting CKD. Furthermore, the study revealed some significant features from lab events and comorbidities. The study also provides some recommendations for future work to explore the potential of a multimodal approach further.

Peripheral blood biomarkers can inform clinical care and drug development. Establishing causality between biomarker and disease is often critical for such applications, but epidemiological studies are limited due to biases from confounding and reverse causation. Mendelian randomization analysis leverages random inheritance of genetic variants at conception to mimic properties of randomized studies and estimate unconfounded effects between biomarker and disease, or vice-versa. This thesis demonstrates the utility of Mendelian randomization as a complementary tool to elucidate observational studies, predict drug safety and repurposing opportunities, and improve diagnostic biomarkers for cardiometabolic diseases. First, we characterized the hypothesized relationship between lipoprotein(a) and atrial fibrillation. We demonstrated both observed and genetically predicted lipoprotein(a) levels were associated with higher risk of atrial fibrillation across multiple independent cohorts. Importantly, risk was partly mediated independent of atherosclerotic cardiovascular disease, a known consequence of elevated lipoprotein(a) and itself a risk factor for atrial fibrillation. Next, we explored the lifelong effects of endogenous testosterone across a comprehensive set of 461 health outcomes in 161,268 males from the UK Biobank cohort. Using Mendelian randomization analysis, we found higher testosterone had beneficial effects on body composition and bone mineral density but adverse effects on prostate cancer, androgenic alopecia, spinal stenosis, and hypertension. Finally, we applied Mendelian randomization with the intention of discovering biomarkers caused by disease, which are expected to represent markers of early disease. As a proof-of-concept, we applied this framework to identify biomarkers associated with genetic predisposition to kidney function among 238 biomarkers measured in the ORIGIN trial. We discovered reduced kidney function caused increased trefoil factor 3 and showed its addition to models with known risk factors improved discrimination of incident early-stage chronic kidney disease. Taken together, Mendelian randomization identified biomarkers that warrant further study, with promising implications for screening, prevention, and treatment of different cardiometabolic diseases. / Thesis / Doctor of Philosophy (PhD) / Biological markers associated with disease can inform novel therapeutics or diagnostics but distinguishing causation from correlation is challenging. Mendelian randomization – a technique that leverages random inheritance of genetic variation to infer causality – was used to examine the role of biomarkers in cardiometabolic diseases. First, we implicated lipoprotein(a) as a risk factor for atrial fibrillation that acts independent of atherosclerotic cardiovascular disease. Second, we comprehensively characterized the lifelong effects of testosterone on health outcomes in males, where we found evidence of both beneficial and adverse effects on disease. Finally, we discovered trefoil factor 3 as a diagnostic marker for early-stage chronic kidney disease. Altogether, this thesis demonstrated different applications of Mendelian randomization that showcase its utility as a complementary tool to reveal causal biomarkers, and served to identify biomarkers for cardiometabolic diseases that merit further studies to evaluate their potential benefit on patient care.