Magister Scientiae (Medical Bioscience) - MSc(MBS) / Background: It is well known that some genetic factors and dietary factors, such as excessive salt intake and excessive caloric intake (resulting in obesity) are risk factors for hypertension. Fifty percent of all hypertensive patients are also insulin resistant. Both hypertension and insulin resistance are again risk factors for other cardiovascular diseases such as atherosclerosis and heart failure. The nature of the association between hypertension and insulin resistance has not been clearly elucidated. Spontaneously hypertensive rats are the ideal models to study the aspects of the relationships between hypertension and insulin resistance. Models of high-fat feeding induce obesity,hypertension and insulin resistance and are thus used extensively to study hypertension because these models closely mimic some of the renal and cardiovascular changes found in human hypertensive patients. The present study was initiated to evaluate if insulin resistance will develop within 6 weeks in a model of high-fat diet induced hypertension and if so, to determine whether captopril will affect the presence of insulin resistance.This model should in future be used to study vascular reactivity to phenylephrine (PHE),acetylcholine (ACH) and sodium nitroprusside (SNP) in hypertensive animals in theabsence or presence of insulin resistance and in normotensive insulin resistant animals. Methods: In a series of experiments, rats were divided into four groups that received different treatments: (i) laboratory pellets, (ii) high-fat diet, (iii) high-fat diet plus captopril and (iv) high-fat diet plus vehicle. Body weight was measured weekly for 6 weeks. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured every week during the 6-weeks feeding period by the tail cuff method using a two channel computerized non-invasive system from Kent Scientific Corporation, USA.m Intraperitonealy glucose tolerance tests (IPGTTs) were performed at week 3 and week 6.After 6 weeks, and after an overnight fast, the plasma lipid profile was determined using a portable CardiochekTM blood test system. Fasting plasma insulin was determined using an immunoenzymatic assay for the in vitro quantitative measurement of rat insulin (INS) in serum and plasma. Insulin sensitivity was estimated by the quantitative insulin sensitivity check index (QUICKI) using the fasting plasma insulin and fasting glucose levels. After week 6 on the high-fat diet, thoracic aortae from the control and high-fat fed(HFD) animals were excised and vascular response to PHE, ACH and SNP were assessed in intact and denuded endothelium.Result: High-fat feeding did not cause a significant increase in body weight. High-fat feeding significantly increased systolic blood pressure from 125±2.1 mmHg in control animals to 155±5.9 mmHg in the HFD group (P < 0.05) and 158±5.6 mmHg in the HFDV group (P < 0.05). Diastolic blood pressure was increased from 86±2.8 mmHg in the control group to 117±2.5 mmHg in the HFD group (P < 0.05) and 113±3.4 mmHg in the HFDV group (P < 0.05). Visceral fat was increased from 0.8±0.1g in the control group to 3.1±0.6 g in the HFD group and 3.8±0.6 g in the HFDV group. IPGTTs performed at weeks 3 and 6 respectively did not differ significantly from the control group as evidenced from the AUC’s at weeks 3 and 6 respectively. High-fat feeding had no significant effects on blood cholesterol, triglyceride, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C) values or and fasting plasma insulin levels. The KCl induced contraction in both aortic rings with intact and denuded endothelium did not differ significantly between the control and HFD groups (P= 0.4 and 0.8) respectively. The contraction mediated by KCl in aortic rings with intact and denuded endothelium from the control or HFD groups also did not differ significantly(control: intact vs denuded, P = 0.2; HFD: intact vs denuded, P = 1). Dose responsecurves(1-10 μM) to PHE indicated slightly stronger contractions in the high-fat fed animals at submaximal doses tested. The maximum contraction achieved was however the same (94±19% and 99±2.6% relative to KCl induced contraction, in the control and HFD group respectively, P<0.05). Relaxation responses to ACH and SNP represent preliminary data.Conclusion: These data suggest that 6 weeks of high-fat feeding induces hypertension but does not produce obesity, dyslipidemia and insulin resistance. However, this model may be useful in studying vascular reactivity in hypertension in the absence of insulin resistance.

O objetivo do primeiro estudo foi avaliar a produção in vitro de embriões (PIVE) em vacas holandesas não lactantes submetidas a aspiração oocitária (OPU) posteriormente ao protocolo de superestimulação folicular similar ao descrito por Nivet et al. (2012) em comparação à realização da OPU em dia aleatório do ciclo estral. Para tal, vacas holandesas não lactantes e não gestantes foram distribuídas aleatoriamente em delineamento tipo crossover em Controle (n = 35), em que as vacas não foram tratadas com FSH, mas submetidas a uma sessão de aspiração em dia aleatório do ciclo estral; ou p-FSH (n = 35), em que, 36 horas após a OPU para sincronização da onda folicular, as vacas foram tratadas com p-FSH por 3 dias e 44 horas após, submetidas a sessões de OPU. O número total de complexos cumulusoócito (CCO) recuperados e o número de oócitos viáveis foram semelhantes entre os grupos controle e p-FSH. Além disso, não houve aumento na proporção de CCO viáveis (CCO viáveis / CCO total recuperado). Da mesma forma, não se detectaram diferenças no número de embriões / sessão de OPU e taxa de blastocistos. O protocolo de superestimulação folicular não melhorou a PIVE em vacas holandesas não lactantes. O experimento 2 testou a hipótese de que vacas leiteiras de alta produção se tornam cada vez mais resistentes à insulina com o avançar da lactação, e consequentemente, a qualidade do oócito é comprometida. Foram utilizadas vacas holandesas em 50 (51,5 ± 3,7; n = 30), 100 (102,3 ± 9,4; n = 30) e 150 (154,5 ± 18,9; n = 30) dias em lactação (DEL). Durante o teste de tolerância à glicose (TTG), não houve diferença entre grupos para qualquer variável relacionada à glicose circulante. No entanto, medidas de insulina circulante foram diferentes em vacas aos 150 DEL em comparação com 50 ou 100 DEL, tais como: maior insulina basal, pico, &Delta; máx de insulina e AUC 5-60. Porém, não houve diferença entre os grupos para o número ou percentagem de oócitos viáveis. Assim, as vacas desenvolveram resistência à insulina com o aumento do DEL. No entanto, o aumento da resistência à insulina não foi associado com alteração detectável na qualidade dos oócitos aspirados de folículos pequenos e médios. O experimento 3 foi para avaliar se o aumento de insulina circulante durante os períodos de pré e pós desvio folicular aumenta o desenvolvimento inicial e final, do folículo, bem como do corpo lúteo (CL). Além disso, por induzir a ovulação de um folículo maior, o CL resultante de vacas com alta insulina circulante também é maior e mais esteroidogênico, refletindo em maiores concentrações circulantes de progesterona (P4). O delineamento experimental utilizado foi o quadrado latino em arranjo fatorial 2x2, em quatro grupos experimentais: 1) CC = água pré e pós desvio folicular (n = 16); 2) CP = água e propilenoglicol (PPG) pré e pós desvio folicular, respectivamente (n = 16); 3) PC = PPG e água pré e pós desvio folicular, respectivamente (n = 16) e 4) PP = PPG pré e pós desvio folicular (n = 16). O aumento agudo e transitório, durante os períodos de pré e pós desvio não aumentou o desenvolvimento folicular, luteal e concentrações plasmáticas de P4. / The aim of the first study was to evaluate the in vitro embryo production (IVEP) in nonlactating Holstein cows subjected to ovum pick-up (OPU) after ovarian superstimulation with a protocol similar to that described by Nivet et al. (2012) in comparison with OPU at a random day of the estrous cycle. Nonlactating Holstein cows were randomly assigned in a crossover design to: Control (n = 35) in which cows were not treated with p-FSH, but subjected to OPU at a random day of the estrous cycle; or p-FSH (n = 35), in which, 36 hours after OPU to synchronize follicle wave, the cows were treated with p-FSH for 3 days and 44 hours later, subjected to OPU sessions. The total number of cumulus-oocyte complex (COC) recovered and the number of viable oocytes were similar between control and p-FSH groups. In addition, there was no increase in the proportion of viable COC (viable COC / overall COC recovered). Likewise, we detected no differences in the number of embryos / OPU session and blastocyst rate. Follicle superstimulation protocol with p-FSH did not improve IVEP in nonlactating Holstein cows. Experiment 2 tested the hypothesis that high-producing dairy cows become increasingly resistant to insulin with advancing lactation, and consequently oocyte quality is compromised. We used Holstein cows at 50 (51.5 ± 3.7; n = 30), 100 (102.3 ± 9.4; n = 30) and 150 (n = 30 154.5 ± 18.9) days in milk (DIM). During the glucose tolerance test (GTT), there was no difference between groups for any variable related to circulating glucose. However, circulating insulin measurements such as basal insulin, peak insulin, &Delta; max and AUC 5-60 were higher for cows at 150 DIM. Nevertheless, there was no difference between groups for the number or percentage of viable oocytes. Therefore, although cows developed insulin resistance with increasing DIM, this has not been associated with detectable change in the quality of oocytes aspirated from small and medium follicles. The third experiment assessed whether the increase in circulating insulin during periods of pre- and post-follicle deviation increases the initial and final follicle size and corpus luteum (CL) volume. Moreover, by inducing ovulation of greater follicles, resulting in greater CL, cows with high circulating insulin also have higher circulating progesterone (P4). The experimental design was a Latin square in a 2x2 factorial arrangement in four groups: 1) CC = water pre and post follicle deviation (n = 16); 2) CP = water pre and propylene glycol (PPG) post follicle deviation (n = 16); 3) PC = PPG and water pre and post follicle deviation, respectively (n = 16), 4) PP = PPG pre and post follicle deviation (n = 16). Acute and transient circulating insulin increase during periods of pre and post follicle deviation has not affected follicle development, luteal volume or plasma concentrations of P4.

Das Metabolische Syndrom (MetSyn) ist gekennzeichnet durch eine Kombination verschiedener kardiovaskulärer Risikofaktoren: Glukoseintoleranz, Adipositas, Dyslipidämie sowie arterielle Hypertonie. Es gilt beim Menschen als eine der Hauptursachen für Herzkreislauferkrankungen und befindet sich weltweit auf enormem Vormarsch. Die Weichen für die Erkrankung werden zum Teil schon vor der Geburt durch eine veränderte Umwelt in utero gestellt. So können Stress oder eine Glukokortikoidbehandlung während der Schwangerschaft zu einem veränderten Phänotyp des Embryos/Fetus führen - mit Konsequenzen für das gesamte spätere Leben. Dieses Phänomen wird als pränatale Programmierung bezeichnet. Neben diesen epigenetischen Effekten spielen u. a. auch geschlechtsabhängige Faktoren eine Rolle für das Risiko, am MetSyn zu erkranken. Die vorliegende Arbeit befasst sich mit den Auswirkungen einer Glukokortikoidbehandlung in der frühen Trächtigkeit sowie dem Einfluss des Geschlechts auf kardiovaskuläre Risikofaktoren im Erwachsenenalter. Als Modelltier für die Studie wurde der Weißbüschelaffe eingesetzt. In einem 2002 stattgefundenen Vorversuch im Deutschen Primatenzentrum in Göttingen wurde tragenden Tieren (F0) eine Woche lang täglich oral Dexamethason verabreicht. Dieses synthetische Glukokortikoid kann die Plazentaschranke passieren. Die drei folgenden in Leipzig gehaltenen Generationen DexF1/2/3W (weibliche Tiere, n = 4/6/2) und DexF2/3M (männliche Tiere, n = 2/4) gingen in die Untersuchung ein. Tiere, die keine Nachkommen der F0-Generation darstellten, bildeten jeweils eine weibliche (ControlW, n = 11) und eine männliche (ControlM, n = 15) Kontrollgruppe und wurden ebenfalls herangezogen, um die Auswirkungen des Geschlechts auf die untersuchten Parameter zu ermitteln. Es wurde ein oraler Glukosetoleranztest (OGTT) durchgeführt (inklusive der Erfassung der Insulinwerte), der Quantitative Insulin Sensitivity Check Index (QUICKI – Maß für die Insulinsensitivität) berechnet sowie Lipidstoffwechselparameter bestimmt. Außerdem fanden wöchentlich Erfassungen des Körpergewichts statt. In mehreren Sitzungen pro Tier wurde der Blutdruck gemessen. Die statistische Auswertung erfolgte mittels Mann-Whitney-U-Test für unabhängige Stichproben. Unterschiede mit einer Irrtumswahrscheinlichkeit p ≤ 0,05 wurden als signifikant angesehen. Im OGTT wies DexF1W im Vergleich zu ControlW 120 Minuten nach oraler Glukoseapplikation eine signifikant niedrigere Insulinkonzentration auf. Da nach 30 und 120 Minuten auch die Glukosekonzentration signifikant erniedrigt war, ist jedoch nicht von einer klinischen Relevanz auszugehen. Weitere Auswirkungen der Dexamethasonapplikation auf die F1- bis F3-Generation konnten nicht beobachtet werden. Beim Vergleich der weiblichen und männlichen Nachkommen unbehandelter Weißbüschelaffen fiel auf, dass weibliche Tiere signifikant höhere Insulinkonzentrationen und damit eine signifikant größere Insulin-AUC (Fläche unter der Kurve) im OGTT zeigten. Ihr QUICKI war signifikant niedriger. Hyperinsulinämie und niedriger QUICKI stellen Symptome einer gestörten Glukoseregulation dar. Die weiblichen Tiere zeigten außerdem eine signifikante Erhöhung hinsichtlich Körpergewicht, VLDL-Triglycerid- und folglich Plasmatriglyceridkonzentrationen. Ihre HDL-Cholesterolwerte waren signifikant niedriger. Diese Kombination einer Hypertriglyceridämie mit niedrigem HDL-Cholesterol wird als atherogene Dyslipidämie bezeichnet. Eine gestörte Glukosehomöostase, eine Adipositas sowie eine atherogene Dyslipidämie stellen kardiovaskuläre Risikofaktoren und wichtige Komponenten des MetSyn dar. Zusammenfassend lässt sich sagen, dass beim Weißbüschelaffen eine Glukokortikoidbehandlung während der frühen Trächtigkeit nicht zum MetSyn der F1- bis F3-Generationen im Erwachsenenalter führte. Hingegen ergab die Untersuchung auf ein geschlechtsabhängiges Erkrankungsrisiko eine eindeutige Prädisposition bei den weiblichen Tieren. Die zu Grunde liegenden Mechanismen dieses Phänomens bleiben Gegenstand weiterer Untersuchungen. / The metabolic syndrome (MetSyn) consists of a cluster of metabolic disorders, characterized by glucose intolerance, obesity, dyslipidemia and hypertension. In humans, it is a major cause for cardiovascular disease. Its worldwide prevalence is increasing. The way for the disease can be paved even before birth. An adverse intrauterine environment due to prenatal stress or an iatrogenic overexposure of the fetus to glucocorticoids can lead to an altered phenotype with consequences for later life. This phenomenon is called prenatal programming. In addition gender specific factors play a leading role for the risk of developing MetSyn. The aim of the present study was to investigate the influence of a glucocorticoid application in early pregnancy and gender on cardiovascular risk factors in adulthood. The common marmoset was used as model species. In a preliminary experiment (2002) at the german primate centre (Göttingen) animals (F0) were orally treated with dexamethasone for one week during early pregnancy. Dexamethasone is a synthetic glucocorticoid that can pass the placental barrier. The following three generation offspring, reared in Leipzig, DexF1/2/3W (female animal, n = 4/6/2) and DexF2/3M (male animal, n = 2/4) were regarded. Animals that were no descendants of the F0 generation built a female (ControlW, n = 11) and a male (ControlM, n = 15) control group and were also regarded for gender-specific risk for MetSyn. An oral glucose tolerance test (OGTT) was carried out (including measurements of insulin concentration), the Quantitative Insulin Sensitivity Check Index (QUICKI – measure of insulin sensitivity) was calculated and parameters of lipid metabolism were investigated. Furthermore, all animals were weighed weekly and blood pressure was monitored at a series of meetings. Statistical analysis was performed by Mann-Whitney-U-Test for independent samples. The level of significance was defined at p ≤ 0.05. DexF1W in comparison to ControlW had a significantly lower insulin concentration 120 minutes after glucose application in the OGTT and a significantly lower glucose concentration 30 and 120 minutes after reaching the sugar solution. These findings did not seem to be clinically relevant. Apart from that, no consequences could be determined in the F1-3 generation offspring after dexamethasone treatment in pregnancy. Regarding gender comparison of untreated common marmosets, female animals had significantly higher insulin concentrations in OGTT and therefore a significantly greater insulin AUC (area under the curve). QUICKI was significantly lower. Hyperinsulinemia and a low QUICKI are symptoms of an impaired glucose regulation. Furthermore, the female animals showed an increase in body weight, VLDL triglycerides and therefore total triglycerides. HDL cholesterol was significantly lower. Hypertriglyceridemia in combination with low HDL cholesterol is called atherogenic dyslipidemia. A disturbed glucose homeostasis, obesity and an atherogenic dyslipidemia are cardiovascular risk factors and important components of MetSyn. In summary, dexamethasone applied in early pregnancy did not lead to metabolic syndrome in the F1-F3 generation offspring of common marmoset in adulthood. However, the female gender was associated with a higher risk of developing the disease. The underlying mechanisms require further investigation.

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第19892号 / 医博第4141号 / 新制||医||1016(附属図書館) / 32969 / 京都大学大学院医学研究科医学専攻 / (主査)教授 川村 孝, 教授 横出 正之, 教授 妹尾 浩 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

<p dir="ltr">Obesity is a worldwide epidemic that is partially linked to changing lifestyles within the modern world, including increased access to calorically dense foods and decreased energy output due to more sedentary jobs. Obesity can lead to many different health complications, such as cardiovascular diseases or Type 2 Diabetes (T2D). Obesity-induced T2D is caused by dysfunction of the insulin-producing beta cells of the pancreas. However, mechanisms that promote obesity and the mechanisms by which obesity leads to beta cell dysfunction are not fully known.</p><p dir="ltr">Spinophilin is a filamentous (F)-actin binding, protein scaffolding, and protein phosphatase 1 (PP1)-targeting protein that can regulate protein. Spinophilin has multiple actions. Spinophilin can bundle filamentous actin to modulate the cellular cytoskeleton. Spinophilin also mediates substrate phosphorylation by targeting and modulating PP1 activity. In addition, spinophilin interacts with multiple proteins, including certain G-protein coupled receptors and can scaffold them with F-actin and/or PP1. Previous studies established that spinophilin KO mice have decreased fat mass, increased lean mass, and improved glucose tolerance. Yet, how spinophilin modulates the above metabolic parameters is unclear. We found that spinophilin is expressed in hypothalamic tissue and appears to also be expressed in the feeding center of the hypothalamus, as well as in other glucose-sensing cells known as tanycytes that neighbor the arcuate nucleus and the third ventricle. We found that loss of spinophilin limited weight gain observed in both a leptin receptor db/db mouse line (Leprdb/db<i>)</i> and mice fed a high-fat diet. Moreover, we found that the decreased fat mass seen in global spinophilin KO mice, at least in the Leprdb/db mice, was not due to major differences in feeding behaviors, consistent with what was observed by other groups using high-fat diet-fed mice. </p><p dir="ltr">As spinophilin was not associated with alterations in feeding, we posited that its ability to modulate glucose homeostasis may be linked to non-neuronal actions of the protein. Previous studies have found that spinophilin may regulate adipose tissue function and <i>in vitro</i> pancreatic beta cell function; however, its role in the pancreas and beta cells <i>in vivo</i> is not well characterized. We found that spinophilin is expressed in mouse pancreas. Using proteomics-based approaches we identified multiple putative spinophilin interacting proteins isolated from intact pancreas, including: PP1, the spinophilin homolog neurabin, and myosin-9. KEGG pathway analysis of proteomic proteins identified multiple pathways regulating ER stress, such as the unfolded protein response, and cytoskeletal arrangement. We observed decreased associations of spinophilin with PP1 and neurabin and increased association with myosin-9 in obese, Leprdb/db mice as early as 6 weeks, as well as significant decreases in body weight when spinophilin was knocked out in Leprdb/db mice. Moreover, we confirmed a robust and specific increased interaction of spinophilin with myosin-9, and other cytoskeletal proteins. Additionally, we found specific spinophilin interactions with ribosomal proteins, and exocrine and digestion proteins in high-fat diet-fed mice. Using our recently generated pancreatic beta cell-specific spinophilin KO mice, we found that loss of spinophilin in mice on a high-fat diet significantly reduces weight gain and improves whole- body glucose tolerance, and loss of spinophilin specifically within the beta cells also improves whole-body glucose tolerance, with no effect on body weight, further suggesting cell type-specific and independent roles for spinophilin on body weight and glucose homeostasis.</p>

Résumé L’augmentation de l’espérance de vie chez les patients atteints de fibrose kystique (FK) entraine une augmentation de la prévalence des anomalies de tolérance au glucose, soit l’intolérance au glucose (IGT) et le diabète (DAFK). En dépit du fait, que les anomalies de la tolérance au glucose soient associées à un mauvais prognostic, l’origine de ces troubles n’est pas encore clairement établie. Notre objectif était d’examiner le rôle de l’insulinopénie et de la résistance à l’insuline dans la détérioration de la tolérance au glucose dans une cohorte prospective observationelle patients FK non diabétique. Nos résultats démontrent une réduction marquée de la phase précoce de la sécrétion de l’insuline ainsi qu’une augmentation de l’aire sous la courbe de la glycémie (AUC) chez tous les groupes de patients. Nous avons aussi démontré qu’une variation de la sensibilité à l’insuline joue un rôle prépondérant dans les changements de catégorie de tolérance au glucose dans cette population. Finalement, il semblerait que l’augmentation de l’AUC du glucose et la réduction de la phase précose de la sécrétion d’insuline sont des meileurs prédicateurs du status clinique que les catégories de tolérance au glucose. Il existe plusieurs indices pour évaluer la sécrétion d’insuline et pourtant aucun n’a été validé chez les patients FK. Nous avons examiné la validité des index de la sécrétion de l’insuline dérivés de l’hyperglycémie provoquée par voie orale (HGPO) ainsi que des valeurs à jeun par rapport au test de référence. Alors que la plupart des index calculés à partir de l’HGPO corrèlent significativement avec les valeurs du test de référence, cela n’est pas le cas pour les index calculés à partir des valeurs à jeun. La validation de ces index nous permet d’évaluer la sécrétion de l’insuline prospectivement dans notre cohorte de FK à partir de l’HGPO, est un test recommandé pour le dépistage du DAFK. Les recommandations nutritionnelles suggèrent aux patients FK une diète comprenant environ 40% de lipides afin d’éviter la malnutrition. Nous avons examiné le profil lipidique des patients FK diabétiques et non diabétiques après une HGPO et un repas hyperlipidique (RT). Nos résultats démontrent que la FK est associée à des augmentations de l’excursion glycémique lors de l’HGPO ou d’un RT comparativement aux témoins. Cependant, le RT provoque 1) une plus faible excursion glycémique comparativement à l’HGPO ; 2) une meilleure suppression de la production hépatique de glucose et 3) l’excursion lipidique postprandiale des patients FK reste normale. Il est donc peu probable que les anomalies de la sécrétion de l’insuline par les cellules  soient secondaires à une lipotoxicité. Nous avons aussi examiné les taux d’adiponectine, une hormone sécrétée par le tissu adipeux et pouvant moduler l’action de l’insuline. Les niveaux d’adiponectine corrèlent négativement avec plusieurs facteurs présents chez les patients FK incluant l’IGT, l’inflammation et une adiposité centrale en dépit d'un faible poids corporel. Les patients FK ne présentaient aucune altération des taux d’adiponectine malgré la présence d’une résistance à l’insuline, une inflammation sub-clinique et de l’IGT. La FK apparaît donc comme une condition où il existe une discordance entre les taux d’adiponectine et la résistance à l’insuline ou l’inflammation. En conclusion la prévalence de l’IGT est élevée dans cette population caractérisée par une excursion glycémique anormalement plus élevée, due principalement à une altération de la sécrétion de l’insuline exacerbée par une résistance à l’insuline. Mots clés : Adiponectine, Hyperglycémie par voie oral (HGPO), intolérance au glucose, fibrose kystique, diabète, résistance à l’insuline, sécrétion de l’insuline. / Abstract Abnormal glucose tolerance is a frequent co-morbidity in cystic fibrosis patients (CF), and is associated with a worse prognosis. However, the most pertinent factors to predict the clinical status and the physiopathology of glucose intolerance remain unclear. The aim of this study was to investigate the roles of impaired insulin secretion and insulin resistance in the progression of glucose intolerance from the normal state up to diabetes (CFRD) using an ongoing prospective observational cohort of non-diabetic CF patients. We demonstrated that CF patients displayed a reduced first phase insulin secretion across glucose tolerance categories (normal; intolerance and CFRD). Moreover, variation in insulin resistance has a significant impact on glucose tolerance in this population. Finally, early in the course of the disease, increased glucose area under the curve (AUC) and reduced first phase insulin secretion are better predictors of clinical status than conventional glucose tolerance categories. Numerous indices to evaluate insulin secretion have been proposed, but their validity has not been explored in cystic fibrosis (CF). The aim of this study was to validate surrogate indices of insulin secretion calculated from fasting values or the oral glucose tolerance test (OGTT) in CF patients against the gold standard, the intravenous glucose tolerance test (IVGTT). This is an essential step to study the physiopathological role of defective insulin secretion in the development of CFDR in large cohort. We showed that all insulin secretion indices correlated significantly with the IGVTT in control individuals. However, while OGTT-derived indices correlated significantly with the gold standard test in all CF groups, this was not the case for fasting-derived indices. Since the OGTT is required on a regular basis in CF patients to screen for CFRD, OGTT-derived indices should be used to evaluate insulin secretion. Abnormal insulin secretion combined with recommended high fat intake could be associated with dysregulation of glucose and lipid metabolisms in CF patients. Thus, the second objective was to examine postprandial glucose and lipid profiles during an OGTT and a standardized high-fat test meal (TM) in CF patients. CF patients presented higher glucose excursion compared to controls after the OGTT and TM. This excursion was significantly reduced in both amplitude and length during the TM for CF patients. In addition, control and CF patients presented similar profiles for both triglycerides and fatty acids. These results exclude lipotoxicity as a major player in ß cell defect for these patients. Circulating adiponectin levels are negatively associated with glucose intolerance, inflammation and central adiposity. Since these conditions are common in CF patients, we examined whether adiponectin values are altered in this population. CF patients did not show any changes in adiponectin levels despite insulin resistance, glucose intolerance and sub-clinical inflammation. Thus, CF appears to be one of the rare conditions in which discordance between adiponectin values and insulin resistance or inflammation is evident. In conclusion, CF patients are characterized by a high prevalence of glucose abnormalities due to an insulin secretion defect but also the contribution of insulin resistance. Key words: Adiponectin, Cystic fibrosis, diabetes, glucose intolerance, Oral glucose tolerance test, insulin resistance, insulin secretion.

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.

Introdução: A doença cardiovascular prematura é uma das maiores causas de morbi-mortalidade no lúpus eritematoso sistêmico (LES) e parece estar relacionada à maior prevalência de fatores de risco clássicos e não clássicos. A resistência à insulina (RI) é um importante fator de risco para doenças cardiovasculares (DCV), podendo ter papel no risco cardiovascular aumentado no LES. Objetivo: Avaliar a sensibilidade à insulina de pacientes com LES em resposta ao teste oral de tolerância à refeição (MTT - Meal tolerance test), controlando por potenciais variáveis intervenientes, a saber, nível de atividade física, composição corporal e consumo alimentar. Metodologia: Pacientes com LES (LES; n=33) recrutadas no ambulatório de Reumatologia do HC-FMUSP e voluntárias saudáveis (CTRL; n = 16), pareadas por idade, gênero e índice de massa corporal foram selecionadas. As participantes foram submetidas ao MTT para determinação de estimativas da sensibilidade à insulina e de função das células beta, nível de atividade física (acelerometria), composição corporal (DXA), consumo alimentar (recordatórios alimentares), concentração de adipocinas e citocinas inflamatórias, atividade da doença e uso de medicamentos. Resultados: LES e CTRL apresentaram glicemia de jejum e em resposta ao MTT similares. Em contrapartida, LES apresentou maior insulinemia de jejum, HOMA RI, razão insulina/glicose de jejum e em resposta ao MTT, glucagonemia de jejum e em resposta ao MTT (p < 0,05) e tendência ao menor Índice de sensibilidade à inulina Matsuda (p = 0,06) e à maior insulinemia em resposta ao MTT (p=0,09) quando comparado ao CTRL. Em relação às estimativas da função das células beta, a razão pró-insulina/insulina de jejum e em resposta ao MTT foram similares entre os grupos, embora o grupo LES tenha apresentado maior índice insulinogênico (p=0,02). Conclusão: O grupo LES apresentou maior RI e hiperglucagonemia apesar de tolerância normal à glicose e função preservada das células beta quando comparado ao grupo controle. Esses resultados sugerem que os pacientes LES possuem maior risco de desenvolver DCV quando comparados a sujeitos saudáveis com composição corporal, ingestão alimentar e nível de atividade física similares, o que reforça a necessidade de estratégias para melhorar a sensibilidade à insulina, potencialmente prevenindo ou retardando o surgimento de DCV no LES / Background: Premature cardiovascular disease (CVD) is one of the leading causes of morbidity and mortality in systemic lupus erythematosus (SLE) and may be associated with classic and non-classic risk factors. Insulin resistance (IR) is an independent risk factor for CVD and could play a fundamental role in the substantially increased CVD risk in SLE. Objective: To assess insulin sensitivity in a cohort of patients with systemic lupus erythematosus (SLE) fasting and in response to a meal tolerance test (MTT), controlling by potential intervening components, such as physical activity level, body composition and food intake. Methods: SLE patients (LES; n=33) recruited in the HC-FMUSP ambulatory of rheumatology and 16 age- and BMI-matched healthy women (CTRL) were selected. The participants underwent a mixed meal test for assess insulin sensitivity and beta-cell function. Further measurements included physical activity level (assessed by accelerometry), body composition (assessed by DXA), food intake (assessed by a 3-day food record), inflammatory cytokines and adipokines concentrations, disease activity and drug intake. Results: SLE and CTRL showed similar fasting glucose and glucose response to the MTT. In contrast, SLE showed higher fasting insulin levels, HOMA IR, fasting insulin-to-glucose ratio, insulin-to-glucose ratio response to the MTT, fasting glucagon levels, glucagon response to the MTT (p < 0.05), and a tendency towards a lower Matsuda index of whole-body insulin sensitivity (p = 0.06) and a higher insulin response to the MTT (p = 0.09) when compared with CTRL. With respect to the beta-cell function estimates, fasting proinsulin-to-insulin ratio and proinsulin-to-insulin ratio response to the MTT were similar between groups, although SLE showed a higher insulinogenic index (p = 0.02). Conclusion: SLE group showed increased IR and hyperglucagonemia despite normal glucose tolerance and preserved beta-cell function when compared with healthy controls. These results suggest that SLE patients are at higher risk of developing CVD, when compared with healthy subjects with similar body composition, food intake and physical activity level, which reinforces the need of strategies capable of ameliorating insulin sensitivity, thus, potentially preventing or delaying the onset of CVD in SLE

Introdução: A doença cardiovascular prematura é uma das maiores causas de morbi-mortalidade no lúpus eritematoso sistêmico (LES) e parece estar relacionada à maior prevalência de fatores de risco clássicos e não clássicos. A resistência à insulina (RI) é um importante fator de risco para doenças cardiovasculares (DCV), podendo ter papel no risco cardiovascular aumentado no LES. Objetivo: Avaliar a sensibilidade à insulina de pacientes com LES em resposta ao teste oral de tolerância à refeição (MTT - Meal tolerance test), controlando por potenciais variáveis intervenientes, a saber, nível de atividade física, composição corporal e consumo alimentar. Metodologia: Pacientes com LES (LES; n=33) recrutadas no ambulatório de Reumatologia do HC-FMUSP e voluntárias saudáveis (CTRL; n = 16), pareadas por idade, gênero e índice de massa corporal foram selecionadas. As participantes foram submetidas ao MTT para determinação de estimativas da sensibilidade à insulina e de função das células beta, nível de atividade física (acelerometria), composição corporal (DXA), consumo alimentar (recordatórios alimentares), concentração de adipocinas e citocinas inflamatórias, atividade da doença e uso de medicamentos. Resultados: LES e CTRL apresentaram glicemia de jejum e em resposta ao MTT similares. Em contrapartida, LES apresentou maior insulinemia de jejum, HOMA RI, razão insulina/glicose de jejum e em resposta ao MTT, glucagonemia de jejum e em resposta ao MTT (p < 0,05) e tendência ao menor Índice de sensibilidade à inulina Matsuda (p = 0,06) e à maior insulinemia em resposta ao MTT (p=0,09) quando comparado ao CTRL. Em relação às estimativas da função das células beta, a razão pró-insulina/insulina de jejum e em resposta ao MTT foram similares entre os grupos, embora o grupo LES tenha apresentado maior índice insulinogênico (p=0,02). Conclusão: O grupo LES apresentou maior RI e hiperglucagonemia apesar de tolerância normal à glicose e função preservada das células beta quando comparado ao grupo controle. Esses resultados sugerem que os pacientes LES possuem maior risco de desenvolver DCV quando comparados a sujeitos saudáveis com composição corporal, ingestão alimentar e nível de atividade física similares, o que reforça a necessidade de estratégias para melhorar a sensibilidade à insulina, potencialmente prevenindo ou retardando o surgimento de DCV no LES / Background: Premature cardiovascular disease (CVD) is one of the leading causes of morbidity and mortality in systemic lupus erythematosus (SLE) and may be associated with classic and non-classic risk factors. Insulin resistance (IR) is an independent risk factor for CVD and could play a fundamental role in the substantially increased CVD risk in SLE. Objective: To assess insulin sensitivity in a cohort of patients with systemic lupus erythematosus (SLE) fasting and in response to a meal tolerance test (MTT), controlling by potential intervening components, such as physical activity level, body composition and food intake. Methods: SLE patients (LES; n=33) recruited in the HC-FMUSP ambulatory of rheumatology and 16 age- and BMI-matched healthy women (CTRL) were selected. The participants underwent a mixed meal test for assess insulin sensitivity and beta-cell function. Further measurements included physical activity level (assessed by accelerometry), body composition (assessed by DXA), food intake (assessed by a 3-day food record), inflammatory cytokines and adipokines concentrations, disease activity and drug intake. Results: SLE and CTRL showed similar fasting glucose and glucose response to the MTT. In contrast, SLE showed higher fasting insulin levels, HOMA IR, fasting insulin-to-glucose ratio, insulin-to-glucose ratio response to the MTT, fasting glucagon levels, glucagon response to the MTT (p < 0.05), and a tendency towards a lower Matsuda index of whole-body insulin sensitivity (p = 0.06) and a higher insulin response to the MTT (p = 0.09) when compared with CTRL. With respect to the beta-cell function estimates, fasting proinsulin-to-insulin ratio and proinsulin-to-insulin ratio response to the MTT were similar between groups, although SLE showed a higher insulinogenic index (p = 0.02). Conclusion: SLE group showed increased IR and hyperglucagonemia despite normal glucose tolerance and preserved beta-cell function when compared with healthy controls. These results suggest that SLE patients are at higher risk of developing CVD, when compared with healthy subjects with similar body composition, food intake and physical activity level, which reinforces the need of strategies capable of ameliorating insulin sensitivity, thus, potentially preventing or delaying the onset of CVD in SLE

<p>In patients with diabetes mellitus (DM), acute myocardial infarction (AMI) is a major cause of death. We have studied two populations with respect to the relationship between DM or related glucometabolic disturbances and AMI.</p><p>In the first population, the prevalence of DM and the importance of the glycaemic state for the long-term prognosis in non-diabetic patients were investigated in patients with AMI admitted to the Coronary Care Unite at Västerås Central Hospital.</p><p>In the second population, the prevalence of impaired glucose tolerance (IGT), DM and other metabolic abnormalities was investigated in patients with AMI and without known DM admitted to the Coronary Care Units at Västerås and Karolinska Hospital, Stockholm.</p><p>21% of the patients with AMI had previously known DM and 4% had newly detected DM if diagnosis is based upon fasting blood glucose (F-BG). The glycemic state, measured as HbA1c, at a 5.5 years follow-up was a risk factor for re-infarction and/or death in non-diabetic patients after AMI.</p><p>If an oral glucose tolerance test (OGTT) is performed, 40-45% of all patients with AMI have DM and in addition about 30% have IGT. Both an OGTT and a single post-challenge blood glucose value after 60 minutes performed at hospital discharge, were independent predictors of IGT or DM at follow-up. Insulin resistance, measured by homeostatic model assessment (HOMA-IR), decreased during hospital stay, with no further decrease from hospital discharge to follow-up.</p><p>In summary, the studies in this dissertation have revealed an unexpectedly high prevalence of abnormal glucose tolerance in patients with AMI. The glycaemic state, reflected by HbA1c, in non-diabetic patients after AMI has an impact on the long-term prognosis. Consequently, in all patients with AMI, HbA1c and casual blood glucose should be measured at admission and, at least, F-BG at hospital discharge.</p>