Branched-chain amino acids (BCAA) are a group of essential amino acids consisting of leucine, isoleucine, and valine. Leucine, in particular, has signaling functions affecting protein and energy metabolism. Plasma leucine concentration is positively correlated with obesity and associated metabolic disorders. We set out to test the hypothesis that metabolic dysfunction from high fat diets precedes dysfunctional BCAA metabolism. First, BCAA were supplemented to neonatal pigs for 4 weeks to evaluate whether the anabolic signaling function of leucine could increase muscle growth when fed for a longer duration than in previous studies. Neither normal pigs nor low birth weight pigs, which have naturally impaired muscle growth, grew better in response to BCAA supplementation, despite low birth weight pigs expressing less of the leucine sensing protein Sestrin2 in skeletal muscle. Furthermore, high plasma BCAA concentrations caused by the experimental diets had no effect on adiposity, liver fat accumulation, or expression of genes related to fatty acid synthesis, mitochondrial biogenesis, or energy expenditure in the pigs' livers. Having produced strong evidence that long term BCAA supplementation neither improves lean growth nor causes abnormal fat metabolism, we then tested whether fat supplementation changes BCAA metabolism. Pigs were fed milk replacer formula with either low energy (Control), or high energy from long-chain fatty acids (LCFA) or medium-chain fatty acids (MCFA) for 22 days. Although high fat diets did not increase plasma BCAA concentrations, the MCFA diet in particular caused metabolic changes which could lead to fatty liver disease and decreased oxidative BCAA disposal. Expression of fatty acid synthesizing genes were increased in the livers of pigs fed MCFA formula compared to Control and LCFA formula. Oxidation of α-ketoisocaproic acid was decreased in liver homogenate of pigs fed MCFA and LCFA formulas compared to Control. Additionally, hepatic oxidation of α-ketoisovalerate was decreased, and plasma concentration of α-ketoisovalerate was consequently increased, in pigs fed MCFA formula compared to Control, with LCFA formula causing intermediate results. In future research, it would be valuable to feed high MCFA formula for a longer period of time to determine whether nonalcoholic fatty liver disease will develop, and whether plasma BCAA concentrations will increase due to decreased oxidation. Overall, these studies concluded that long term BCAA supplementation does not increase muscle growth in neonatal pigs, but there is also no indication that they cause obesity or dysfunctional fat metabolism. On the other hand, high fat diets cause impairments in BCAA catabolism which may precede elevated plasma BCAA concentrations. / Doctor of Philosophy / Branched-chain amino acids (BCAA) are essential amino acids which are abundant in plant and animal proteins. In addition, the BCAA leucine has functions in protein and energy metabolism. Leucine consumption induces a signal to build new muscle protein. However, leucine concentration is also higher in blood plasma of obese individuals than in non-obese individuals, which has caused uncertainty regarding the safety of leucine consumption. In order to demonstrate that leucine does not cause obesity, we set out to test the hypothesis that high fat diets cause decreased breakdown of BCAA. In the first study, we tested whether one month of BCAA supplementation could increase muscle growth in neonatal pigs. Neither normal pigs nor low birth weight pigs, which have naturally impaired muscle growth, grew better in response to BCAA supplementation, despite low birth weight pigs expressing less of a leucine sensing protein in skeletal muscle. Furthermore, BCAA supplementation caused higher BCAA concentrations in blood plasma, but did not cause pigs to gain more fat, or cause any changes in liver fat metabolism. Having produced strong evidence that BCAA supplementation neither improves lean growth nor causes abnormal fat metabolism, we then tested whether fat supplementation changes BCAA metabolism. Pigs were fed milk replacer formula which was either low calorie (Control), or high calorie from animal fat, which is rich in long-chain fatty acids (LCFA) or high calorie from coconut oil, which is rich in medium-chain fatty acids (MCFA). Although high fat diets did not increase blood plasma BCAA concentrations, the MCFA formula in particular caused changes which could lead to fatty liver disease and decreased breakdown of BCAA. Genes which synthesize new fatty acids were increased in the livers of pigs fed MCFA formula compared to those fed LCFA and Control formulas. Furthermore, liver samples taken from pigs fed the MCFA and LCFA formulas were less able to fully break down metabolites of leucine compared to pigs fed the Control formula. In addition, liver samples from MCFA fed pigs were less able to fully break down metabolites of the BCAA valine, which led to higher concentrations of that metabolite in the blood plasma of pigs fed MCFA formula compared to pigs fed LCFA or Control formula. In the future, it would be valuable to feed a high MCFA formula for a longer period of time to determine whether nonalcoholic fatty liver disease will develop, and whether blood plasma BCAA concentrations will increase due to decreased breakdown. Overall, these studies concluded that long term BCAA supplementation does not increase muscle growth in neonatal pigs, but there is also no indication that they cause obesity or dysfunctional fat metabolism. On the other hand, high fat diets cause impairments in BCAA breakdown which may lead to elevated BCAA concentrations in blood plasma.

Die gesundheitsfördernden Eigenschaften von grünem Tee sind weitgehend akzeptiert. Den Teecatechinen, insbesondere dem Epigallocatechin-3-gallat (EGCG), werden zahlreiche positive Effekte zugesprochen (z. B. antioxidativ, antikanzerogen, antiinflammatorisch, Blutdruck und Cholesterinspiegel senkend). Die Mechanismen, die zu einer Reduktion der in Tierversuchen beschriebenen Körper- und Fettmasse führen, sind nicht ausreichend geklärt. Ziel dieser Arbeit bestand darin, die kurz- und mittelfristigen Wirkungen einer TEAVIGO®-Applikation (mind. 94 % EGCG) am Mausmodell im Hinblick auf den Energie- und Fettstoffwechsel sowie die Expression daran beteiligter Gene in wichtigen Organen und Geweben zu untersuchen. In verschiedenen Tierversuchen wurde männlichen C57BL/6-Mäusen eine Hochfettdiät (HFD) mit und ohne Supplementation (oral, diätetisch) des entkoffeinierten Grüntee-Extraktes TEAVIGO® in unterschiedlichen Dosierungen gefüttert. Es wurden sowohl kurz- als auch mittelfristige Wirkungen des EGCG auf die Energiebilanz (u. a. indirekte Tierkalorimetrie) und Körperzusammensetzung (NMR) sowie die exogene Substratoxidation (Stabilisotopentechnik: Atemtests, Inkorporation natürlicher 13C-angereicherter Triglyceride aus Maiskeimöl in diverse Organe/Gewebe) und Gen-expression (quantitative real-time PCR) untersucht. Die Applikationsform und ihre Dauer riefen unterschiedliche Wirkungen hervor. Mäuse mit diätetischer Supplementation zeigten bereits nach kurzer Zeit eine verminderte Körperfettmasse, die bei weiterer Verabreichung auch zu einer Reduktion der Körpermasse führte. Beide Applikationsformen resultieren, unabhängig von der Dauer der Intervention, in einer erhöhten Energieausscheidung, während die Futter- und Energieaufnahme durch EGCG nicht beeinflusst wurden. Der Energieverlust war von einer erhöhten Fett- und Stickstoffausscheidung begleitet, deren Ursache die in der Literatur beschriebene Interaktion und Hemmung digestiver Enzyme sein könnte. Besonders unter postprandialen Bedingungen wiesen EGCG-Mäuse erniedrigte Triglycerid- und Glycogengehalte in der Leber auf, was auf eine eingeschränkte intestinale Absorption der Nährstoffe hindeutet. Transkriptanalysen ergaben im Darm eine verminderte Expression von Fettsäuretransportern, während die Expression von Glucosetransportern durch EGCG erhöht wurde. Weiterhin reduzierte EGCG, nach Umstellung von Standard- auf eine maiskeimölhaltige Hochfettdiät, die Inkorporation natürlicher 13C-angereicherter Triglyceride in diverse Organe und Gewebe – insbesondere Leber, viszerales und braunes Fettgewebe sowie Skelettmuskel. Die Analyse der 13C-Anreicherung im Atem der Mäuse und die Energieumsatzmessungen ergaben nach kurzer Applikation eine erhöhte Fettoxidation, die im weiteren Verlauf der Intervention auf eine erhöhte Kohlenhydratoxidation umgeschaltet wurde. Weiterhin war die orale Applikation von EGCG bei gleichzeitiger Fütterung einer Hochfettdiät von makroskopischen und mikroskopischen degenerativen Veränderungen der Leber begleitet. Diese Effekte wurden nach diätetischer Supplementation der Hochfettdiät mit EGCG nicht beobachtet. Zusammenfassend zeigen die Ergebnisse, dass die Körpergewichts- und Fettgewebs-abnahme durch diätetisches EGCG sich durch eine herabgesetzte Verdaulichkeit der Nahrung erklären lässt. Dies führte zu verschiedenen kurz- und mittelfristigen Veränderungen in der Fettverteilung und im Fettmetabolismus. / The health-promoting properties of green tea are widely accepted. Tea catechins, particularly epigallocatechin-3-gallate (EGCG), are attributed to many positive effects (anti-oxidative, anti-cancerogen, anti-inflammatory, blood pressure and cholesterol lowering). Mechanisms leading to a reduction of body mass and fat mass in animal experiments are not fully elucidated. The aim of this study was to examine multiple effects of TEAVIGO® application (at least 94% EGCG) in a mouse model in terms of energy and fat metabolism. Expressions of genes involved in these processes were also determined in different organs and tissues. In several animal studies, male C57BL/6 mice were fed a high fat diet supplemented with decaffeinated TEAVIGO® (oral, dietetic) at different dosages. Short- and medium-term effects of EGCG were investigated on energy balance (indirect animal calorimetry), body composition (NMR), exogenous substrate oxidation (stable isotopes: breath tests, incorporation of naturally 13C-enriched triglycerides from corn oil into various organs/tissues), and gene expression (quantitative real-time PCR). Type of application and its duration elicited different effects. Supplemented mice already showed a reduced body fat mass after short- and medium-term treatment. Further administration lead to a reduction of body weight. Regardless of the duration of intervention, both types of application resulted in an increased energy excretion, while food and energy intake was not affected by EGCG. Fecal energy loss was accompanied by an increased fat and nitrogen excretion, which was probably due to an inhibition of digestive enzymes. Fed mice displayed a decreased triglyceride and glycogen content in liver suggesting a reduced absorption of nutrients in the intestine. This was supported by a decreased expression of intestinal fatty acid transporters. However, expression of glucose transporters was increased after short- and medium term application. Furthermore, EGCG attenuated incorporation of naturally 13C-enriched triglycerides into various organs and tissues – particularly liver, visceral and brown adipose tissue, and skeletal muscle. Analysis of 13C-enrichment in breath and measurement of energy expenditure revealed an initial increased fat oxidation, which was switched to an increased carbohydrate oxidation over time. Besides, a combination of oral administration of EGCG and high fat feeding was accompanied by macroscopic and microscopic deleterious changes in liver. These effects were not observed after dietary supplementation of EGCG. Altogether, reduction in body mass and fat mass by EGCG can be explained by a decreased food digestibility leading to various short- and medium-term changes in fat distribution and lipid metabolism.

Pregnancy toxaemia (ketosis) is a metabolic disease of ewes which occurs during the late gestation as a result of the inability of the pregnant ewe to maintain an adequate energy balance for the fast growing maternal fetal unit. As a result of energy defi-ciency mobilization of lipid reserves results in a doubling of the plasma free fatty acid (FFA) giving rise to fatty liver and increased ketone bodies β-hydroxybutyrate (BHB) in blood and urine. It is associated with a higher rate of mortality and causes severe economic losses. The objective of this study was directed at investigating the relationship between metabolic parameters and cytokine TNFα, to check the interaction between the TNFα and fat metabolism in late pregnant ewes of different breeds, and whether TNFα play a role in the pathogenesis of pregnancy toxaemia, which may serve as marker to early diagnosis of the disease. In this study, 29 pregnant and clinically healthy ewes (16 Merino, 13 Blackhead) were selected out of a flock of sheep. Blood samples were collected at 5, 3, and 1 week be-fore parturition (b.p.) and also 4 weeks after parturition (a.p.). The average numbers of lambs were 2.18 and 1.58 /ewe for Merino and Blackhead breeds respectively. The blood samples were analyzed for the following:  Concentration of metabolic parameters: glucose, insulin, free fatty acids (FFA), β-hydroxybutyrate (BHB), albumin, total protein (TP), iron (Fe), glutamat-dehydro-genase (GLDH), creatin kinase (CK), gamma-glutamyl-transferase (GGT), choles-terol, haptoglobin.  Haematological parameters: Haematocrite (HK), haemoglobin concentration (HB), erythrocyte count (EC), leukocyte count (LC), mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC).  Cytokine TNFα by using ovine TNFα ELISA assay. The results of glucose concentration of pregnant ewes showed significant increase (3.8 mmol/l) in five weeks b.p. and declined with advancing gestation (2.6 mmol/l) one week b.p. Insulin concentration remained constant with an average of 0.11 nmol/l b.p., and then significantly increased to 0.22 nmol/l four weeks a.p. Maximal FFA concentrations were found at five weeks b.p. (976 µmol/l). The levels of FFA showed high levels b.p. compared with reference range (R.R. < 600 µmol/l), and the FFA levels significantly decreased postpartum (four weeks b.p.). while there was significant increasing (p<0.05) in the level of FFA in Merino sheep than in Black-head sheep b.p. On the other hand there was no significant difference a.p. The mean values of BHB in all periods of sampling, period 1(5 w.b.p.), period 2 (3 w.b.p.), period 3 (1 w.b.p.), and period 4 (4 w.a.p.) were 0.37 mmol/l, 0.23 mmol/l, 0.17 mmol/l and 0.3 mmol/l respectively. The mean of BHB indicated normal levels of BHB before and after parturition compared to subclinical ketosis (BHB > 1 mmol/l) and clinical ketoses (BHB > 1.6 mmol/l), and there was a significant difference (p<0.05) in the values of BHB between Blackhead and Merino breeds before parturi-tion while there was no significant difference after parturition. The concentration of TNFα showed elevated levels in all period of sampling before parturition. The TNFα values were 30.4 (17.2, 785.0) ng/ml (median, first, and third quartiles), 35.6 (13.6, 54.3), and 26.6 (13.0, 39.9) ng/ml in period 1(5 w.b.p.), period 2 (3 w.b.p.), and period 3 (1 w.b.p.) respectively. These values decreased to 19.1 (9.9, 33.8) ng/ml at 4 weeks after parturition. Statistical analysis showed that there was a positive correlation between free fatty ac-ids and TNFα. This correlation means that adipose tissue produces TNFα causing insu-lin resistance, which stimulates the lipolysis and leads to an increase of circulatory free fatty acids levels. It is concluded that fat mobilization occurs in the prepartum clinically healthy ewes with a significant increase in the levels of FFA, and also there is an increase in the proinflammatory cytokine TNFα at late gestation which predisposes ewes to pregnancy toxaemia and can aid in the diagnosis of the disease.:Table of contents 1 Introduction…………….…………………………………………………..1 2 Review of literature……....…………….……………………………….….3 2.1 Metabolic condition of ewes in the late pregnancy………….………………3 2.2 Metabolic disorders subacute and acute pregnancy Toxaemia…….………..4 2.3 The Importance and dynamic of the different biochemical parameters glucose, insulin, free fatty acids, and β-hydroxybutyrate of ewes in the late pregnancy…………………….………..….……………………………10 2.3.1 Glucose……………………………………………………………………..10 2.3.2 Insulin………………………………………………………………………12 2.3.3 β-hydroxybutyrate (BHB)…….……………………………………………16 2.3.4 Free fatty acids……………………………………………………………...20 2.4 TNFα and its role in fat metabolism and pregnancy toxaemia………….….22 3 Animals, material and methods……………………………………..……38 3.1 Animals……………………………………………………………………..38 3.2 Clinical examination………………………………………………………..38 3.3 Collection of blood samples……………………………………………..…38 3.4 Analysis of haematological parameters in blood samples……………….....38 3.5 Determination of biochemical parameters………………………………….39 3.6 Determination of haptoglobin by using haptoglobin assay……………...…39 3.6.1 Haptoglobin assay principle………………………………………………..39 3.6.2 Components………………………………………………………………...40 3.6.3 Additional materials required………………………………………………40 3.6.4 Sample and reagent preparation………………………………….….……..40 3.6.4.1 Samples……………………………………………………………………..40 3.6.4.2 Haemoglobin.................................................................................................40 3.6.4.3 Chromogen/Substrate………………………………………………………40 3.6.5 Manual methods (microplate or spectrophotometric)……………………...41 3.6.5.1 Calibrator…………………………………………………………………...41 3.6.5.2 Test temperature…………………………………………………………....41 3.6.5.3 Procedure………………..………………………………………………….41 3.7 Analysis of TNFα by using ovine TNFα ELISA assay…………………….42 3.8 Statistical analysis…………………………………………………….…….43 4 Results.……………………………………………………………………..44 4.1 Clinical examination (observation)…………………………………….…...44 4.2 Biochemical parameters………………………………………………….…44 4.2.1 Glucose………………………………………………………………….…..44 4.2.1.1 Glucose concentrations in all sheep…………………………..…………….44 4.2.1.2 Glucose concentrations in Blackhead sheep…………………………..…....44 4.2.1.3 Glucose concentrations in Merino sheep………………………...…………45 4.2.2 Insulin……………………………………………………………………….45 4.2.2.1 Insulin concentrations in all sheep………………………………..………...45 4.2.2.2 Insulin concentrations in Blackhead sheep………………………..………..46 4.2.2.3 Insulin concentrations in Merino Sheep…………………………………….46 4.2.3 Free fatty acids……………………………………………………………...47 4.2.3.1 Free fatty acid concentrations in all sheep………………………………….47 4.2.3.2 Free fatty acid concentrations in Blackhead sheep………………………....47 4.2.3.3 Free fatty acid concentrations in Merino sheep………………………….....47 4.2.4 β-hydroxybutyrate (BHB)…….…………………………………………….48 4.2.4.1 β-hydroxybutyrate concentrations in all sheep……..……………………....48 4.2.4.2 β-hydroxybutyrate concentrations in Blackhead sheep……… …………....48 4.2.4.3 β-hydroxybutyrate concentrations in Merino sheep…………………...…...49 4.2.5 Tumor necrosis factor alpha (TNFα)………………….……………….…...50 4.2.5.1 TNFα concentrations in all sheep…………..................................................50 4.2.5.2 TNFα concentrations in Blackhead sheep……………………………….....50 4.2.5.3 TNFα concentrations in Merino sheep………………………………….......51 4.2.6 Haptoglobin………………………………………………………………....51 4.2.6.1 Haptoglobin concentrations in all sheep……………………………..…......51 4.2.6.2 Haptoglobin concentrations in Blackhead and Merino sheep…….………..51 4.2.7 Albumin…………………………………………………………………….52 4.2.7.1 Albumin concentrations in all sheep…………………………..…………...52 4.2.7.2 Albumin concentrations in Blackhead and Merino sheep……………….....53 4.2.8 Creatinkinase (CK)…………………………………………………………53 4.2.8.1 Creatinkinase activity in all sheep………………………………………….53 4.2.8.2 Creatinkinase activity in Blackhead and Merino sheep…………………….53 4.2.9 Gamma-Glutamyl Transferase (GGT)………………………….…………..54 4.2.9.1 GGT activity in all sheep…………………………………………………...54 4.2.9.2 GGT activity in Blackhead and Merino sheep……………………………..55 4.2.10 Glutamat-Dehydrogenase (GLDH)………………………………………...56 4.2.10.1 GLDH activity in all sheep…………………………………………………56 4.2.10.2 GLDH activity in Blackhead and Merino sheep………….…………….......56 4.2.11 Total protein………………………………………………………………..57 4.2.11.1 Total protein concentrations in all sheep………………………………...…57 4.2.11.2 Total protein concentrations in Blackhead and Merino sheep……………..57 4.2.12 Cholesterol……………………………………………………………….…58 4.2.12.1 Cholesterol concentrations in all sheep………………………………...…...58 4.2.12.2 Cholesterol concentrations in Blackhead and Merino sheep…………....….58 4.2.13 Iron………………………………………………………………………….59 4.2.13.1 Iron concentrations in all sheep…………………………...………………..59 4.2.13.2 Iron concentrations in Blackhead and Merino sheep………………….........60 4.3 Haematological parameters………………………………………………...60 4.3.1 Haematological parameters in all sheep……………………………………60 4.3.2 Haematological parameters in Blackhead sheep…………………………...61 4.3.3 Haematological parameters in Merino sheep………………………………61 4.3.4 Statistical analysis of haematological parameters………………………….62 4.3.4.1 Haemoglobin concentration (Hb)…………………………………………..62 4.3.4.2 Haematocrite (HK)…………………………………………………………62 4.3.4.3 Mean corpuscular volume (MCV) …………………………………………62 4.3.4.4 Mean corpuscular haemoglobin (MCH)……………………………………62 4.3.4.5 Mean corpuscular hemoglobin concentration (MCHC)……………………63 4.3.4.6 Thrombocytes volume (THB)……………………..…………………….…63 4.3.4.7 Leukocytes (LC)………..…………………………………………………..63 4.3.4.8 Erythrocytes.……………………………………………………………….63 5 Discussion…………………………………………………………………..65 6 Summary…………………………………………………………………..71 7 Zusammenfassung………………………………………………………...73 8 References…………………………………………………………………75 Acknowledgements.......................................................................................................84

Introdução: A Síndrome dos Ovários Policísticos (SOP) é uma doença que implica em várias alterações como metabólicas, endócrinas e de composição corporal. Atualmente têm se discutido sobre medidas não farmacológicas para seu tratamento, e o exercício tem sido indicado como primeira conduta para melhora de diversos parâmetros. Objetivos: Avaliar os efeitos de dois protocolos de treinamento físico aeróbio sobre parâmetros hormonais, metabólicos, inflamatórios, de composição corporal, índices antropométricos e comprimento do telômero em mulheres com SOP. Material e Métodos: Trata-se de um ensaio clínico controlado com alocação aleatória e randomização estratificada pelo índice de massa corporal em 3 grupos: treinamento aeróbio contínuo (AC) com 28 voluntárias, treinamento aeróbio intermitente (AI) com 29 voluntárias e controle sem treinamento (GC) com 30 voluntárias. As avaliações dos parâmetros hormonais, metabólicos, inflamatórios e comprimento do telômero, foram realizadas por meio da dosagem sanguínea; os índices da composição corporal, avaliados pela circunferência de cintura e quadril e a composição corporal por meio da avaliação da absortometria de raio x de dupla energia. As avalições ocorreram antes e após o período de 16 semanas de intervenção do treinamento físico aeróbio ou de observação no grupo controle. Resultados: No grupo AC houve redução da circunferência de cintura (CC) (p = 0,045), circunferência de quadril (p = 0,032), níveis de colesterol total (p <= 0,01), LDL (p = 0,03) e testosterona (p <= 0,01). No grupo AI houve redução da CC (p = 0,014), relação cintura-quadril (p = 0,012), testosterona (p = 0,019) e índice de androgênio livre (p = 0,037). No grupo GC houve aumento da CC (p = 0,049), gordura corporal total (p = 0,015) e percentual da gordura corporal total (%) (p = 0,034), massa total dos braços (p < 0,01), percentual de gordura do tronco (p = 0,033), % de gordura das pernas (p = 0,021) e massa total ginóide (p = 0,011). Não houve alteração nas demais variáveis. Conclusão: Ambos os protocolos de treinamento reduziram índices antropométricos e hiperandrogenismo. O treinamento intermitente foi mais eficiente no controle do hiperandrogenismo, enquanto ocontínuo além de melhorar o hiperandrogenismo, promoveu redução nos parâmetros lipídicos, sem correlação entre a melhora de ambos parâmetros. Adicionalmente, ambos foram eficazes na prevenção do ganho de gordura corporal e do aumento da CC. Não ocorreram alterações após a intervenção no comprimento do telômero e demais variáveis analisadas. / Introduction: A Polycystic Ovary Syndrome (PCOS) is a disease that implicates in various changes like metabolic, endocrine and body composition. At present, non-pharmacological measures have been discussed for its treatment, and exercise has been indicated as the first conduit for improvement of several parameters.. Objectives: To evaluate the effects of two aerobic physical training protocols on hormonal, metabolic, inflammatory parameters, body composition, anthropometric indices and telomere length in women with PCOS. Material and methods: This was a randomized controlled trial and stratified randomized to body mass index into 3 groups: continuous aerobic training (CA) with 28 volunteers, intermittent aerobic training (IA) with 29 volunteers, and control without training with 30 volunteers. The evaluations of hormonal, metabolic, inflammatory parameters and telomere length were performed by means of a blood sample; body composition indices evaluated by waist and hip circumference and body composition by means of dual energy x-ray absorptiometry. The evaluations occurred before and after the 16-week intervention period of aerobic physical training or observation in the control group. Results: In the AC group, waist circumference (WC) (p = 0.045), hip circumference (HC) (p = 0.032), total cholesterol levels (p <= 0.01), LDL (p = 0.03) and testosterone (p <= 0.01). In the AI group there was a reduction in WC (p = 0.014), waist-hip ratio (p = 0.012), testosterone (p = 0.019) and free androgen index (p = 0.037). In the CG group there was an increase in WC (p = 0.049), total body fat (p = 0.015) and percentage (%) (p = 0.034), total arms mass (p <0.01), % trunk fat (p = 0.033), % of leg fat (p = 0.021) and total gynoid mass (p = 0.011). There was no change in the other variables. Conclusion: Both training protocols reduced anthropometric indices and hyperandrogenism. Intermittent training was more efficient in the control of hyperandrogenism, while the continuous, besides improving hyperandrogenism, promoted a reduction in lipid parameters, without correlation between the improvement of both parameters. Additionally, both wereeffective in preventing body fat gain and increased CC. There were no changes after intervention in telomere length and other variables analyzed.

Introdução: A Síndrome dos Ovários Policísticos (SOP) é uma doença que implica em várias alterações como metabólicas, endócrinas e de composição corporal. Atualmente têm se discutido sobre medidas não farmacológicas para seu tratamento, e o exercício tem sido indicado como primeira conduta para melhora de diversos parâmetros. Objetivos: Avaliar os efeitos de dois protocolos de treinamento físico aeróbio sobre parâmetros hormonais, metabólicos, inflamatórios, de composição corporal, índices antropométricos e comprimento do telômero em mulheres com SOP. Material e Métodos: Trata-se de um ensaio clínico controlado com alocação aleatória e randomização estratificada pelo índice de massa corporal em 3 grupos: treinamento aeróbio contínuo (AC) com 28 voluntárias, treinamento aeróbio intermitente (AI) com 29 voluntárias e controle sem treinamento (GC) com 30 voluntárias. As avaliações dos parâmetros hormonais, metabólicos, inflamatórios e comprimento do telômero, foram realizadas por meio da dosagem sanguínea; os índices da composição corporal, avaliados pela circunferência de cintura e quadril e a composição corporal por meio da avaliação da absortometria de raio x de dupla energia. As avalições ocorreram antes e após o período de 16 semanas de intervenção do treinamento físico aeróbio ou de observação no grupo controle. Resultados: No grupo AC houve redução da circunferência de cintura (CC) (p = 0,045), circunferência de quadril (p = 0,032), níveis de colesterol total (p <= 0,01), LDL (p = 0,03) e testosterona (p <= 0,01). No grupo AI houve redução da CC (p = 0,014), relação cintura-quadril (p = 0,012), testosterona (p = 0,019) e índice de androgênio livre (p = 0,037). No grupo GC houve aumento da CC (p = 0,049), gordura corporal total (p = 0,015) e percentual da gordura corporal total (%) (p = 0,034), massa total dos braços (p < 0,01), percentual de gordura do tronco (p = 0,033), % de gordura das pernas (p = 0,021) e massa total ginóide (p = 0,011). Não houve alteração nas demais variáveis. Conclusão: Ambos os protocolos de treinamento reduziram índices antropométricos e hiperandrogenismo. O treinamento intermitente foi mais eficiente no controle do hiperandrogenismo, enquanto ocontínuo além de melhorar o hiperandrogenismo, promoveu redução nos parâmetros lipídicos, sem correlação entre a melhora de ambos parâmetros. Adicionalmente, ambos foram eficazes na prevenção do ganho de gordura corporal e do aumento da CC. Não ocorreram alterações após a intervenção no comprimento do telômero e demais variáveis analisadas. / Introduction: A Polycystic Ovary Syndrome (PCOS) is a disease that implicates in various changes like metabolic, endocrine and body composition. At present, non-pharmacological measures have been discussed for its treatment, and exercise has been indicated as the first conduit for improvement of several parameters.. Objectives: To evaluate the effects of two aerobic physical training protocols on hormonal, metabolic, inflammatory parameters, body composition, anthropometric indices and telomere length in women with PCOS. Material and methods: This was a randomized controlled trial and stratified randomized to body mass index into 3 groups: continuous aerobic training (CA) with 28 volunteers, intermittent aerobic training (IA) with 29 volunteers, and control without training with 30 volunteers. The evaluations of hormonal, metabolic, inflammatory parameters and telomere length were performed by means of a blood sample; body composition indices evaluated by waist and hip circumference and body composition by means of dual energy x-ray absorptiometry. The evaluations occurred before and after the 16-week intervention period of aerobic physical training or observation in the control group. Results: In the AC group, waist circumference (WC) (p = 0.045), hip circumference (HC) (p = 0.032), total cholesterol levels (p <= 0.01), LDL (p = 0.03) and testosterone (p <= 0.01). In the AI group there was a reduction in WC (p = 0.014), waist-hip ratio (p = 0.012), testosterone (p = 0.019) and free androgen index (p = 0.037). In the CG group there was an increase in WC (p = 0.049), total body fat (p = 0.015) and percentage (%) (p = 0.034), total arms mass (p <0.01), % trunk fat (p = 0.033), % of leg fat (p = 0.021) and total gynoid mass (p = 0.011). There was no change in the other variables. Conclusion: Both training protocols reduced anthropometric indices and hyperandrogenism. Intermittent training was more efficient in the control of hyperandrogenism, while the continuous, besides improving hyperandrogenism, promoted a reduction in lipid parameters, without correlation between the improvement of both parameters. Additionally, both wereeffective in preventing body fat gain and increased CC. There were no changes after intervention in telomere length and other variables analyzed.

Les maladies cardiovasculaires (MCV) demeurent au tournant de ce siècle la principale cause de mortalité dans le monde. Parmi les facteurs de risque, l’hypercholestérolémie et l’obésité abdominale sont directement liées au développement précoce de l’athérosclérose. L’hypercholestérolémie familiale, communément associée à une déficience des récepteurs des lipoprotéines de basse densité (LDLR), est connue comme cause de maladie précoce d’athérosclérose et de calcification aortique chez l’humain. La subtilisine convertase proprotéine/kexine du type 9 (PCSK9), membre de la famille des proprotéines convertases, est trouvée indirectement associée aux MCV par son implication dans la dégradation du LDLR. Chez l'humain, des mutations du gène PCSK9 conduisent soit à une hypercholestérolémie familiale, soit à une hypocholestérolémie, selon que la mutation entraîne un gain ou une perte de fonction, respectivement. Il demeure incertain si les individus porteurs de mutations causant un gain de fonction de la PCSK9 développeront une calcification aortique ou si des mutations entraînant une perte de fonction provoqueront une obésité abdominale. Dans cette étude, nous avons examiné : 1) l’effet d’une surexpression de PCSK9 dans le foie de souris sur la calcification aortique ; 2) les conséquences d’une déficience en PCSK9 (Pcsk9 KO), mimant une inhibition pharmacologique, sur le tissu graisseux. Nous avons utilisé un modèle de souris transgénique (Tg) surexprimant le cDNA de PCSK9 de souris dans les hépatocytes de souris et démontrons par tomographie calculée qu’une calcification survient de façon moins étendue chez les souris PCSK9 Tg que chez les souris déficientes en LDLR. Alors que le PCSK9 Tg et la déficience en LDLR causaient tous deux une hypercholestérolémie familiale, les niveaux seuls de cholestérol circulant ne parvenaient pas à prédire le degré de calcification aortique. Dans une seconde étude, nous utilisions des souris génétiquement manipulées dépourvues de PSCK9 et démontrons que l’accumulation de graisses viscérales (adipogenèse) apparaît régulée par la PCSK9 circulante. Ainsi, en l’absence de PCSK9, l’adipogenèse viscérale augmente vraisemblablement par régulation post-traductionnelle des récepteurs à lipoprotéines de très basse densité (VLDLR) dans le tissu adipeux. Ces deux modèles mettent en évidence un équilibre dynamique de la PCSK9 dans des voies métaboliques différentes, réalisant un élément clé dans la santé cardiovasculaire. Par conséquent, les essais d’investigations et d’altérations biologiques de la PCSK9 devraient être pris en compte dans un modèle animal valide utilisant une méthode sensible et en portant une attention prudente aux effets secondaires de toute intervention. / Cardiovascular disease (CVD) is the leading cause of death in the 21st century. Among risk factors, hypercholesterolemia and abdominal obesity are directly linked to premature development of atherosclerosis. Familial hypercholesterolemia, commonly due to low-density lipoprotein receptor (LDLR) deficiency, is known to cause premature atherosclerosis and aortic calcification in humans. Proprotein convertase subtilisin/kexin 9 (PCSK9), a member of the proprotein convertase family, is indirectly associated with CVD through enhanced LDLR degradation. Mutations in the human PCSK9 gene lead to either familial hypercholesterolemia or hypocholesterolemia, depending on whether the mutation causes a gain or a loss of function, respectively. It is uncertain if individuals carrying mutations causing a gain-of-function of PCSK9 will develop aortic calcification or whether loss-of-function mutations will lead to abdominal obesity. In this thesis, we investigated: 1) the effect of PCSK9 overexpression on aortic calcification; 2) the consequences of PSCK9 deficiency, mimicking pharmacological inhibition of PCSK9 on fat tissue. We employed a transgenic (Tg) mouse model overexpressing mouse PCSK9 and illustrated by micro-computerized tomography that calcification occurs to a lesser extent in PCSK9 Tg mice than in LDLR-deficient mice. While both PCSK9 Tg and LDLR deficiency caused familial hypercholesterolemia, circulating cholesterol levels alone could not dictate the degree of aortic calcification. In another study, we used genetically modified mice lacking PCSK9 and demonstrated that visceral fat accumulation (adipogenesis) is regulated by circulating PCSK9. Thus in the absence of PCSK9, visceral adipogenesis increases likely via post-translational regulation of very-low-density lipoproteins receptors (VLDLR) in the adipose tissue. In conclusion, these two studies highlight the dynamic balance of PCSK9 in different metabolic pathways, making it a key element in cardiovascular health. Consequently, attempts to survey and/or alter PCSK9 biology should be performed in a valid animal model using sensitive methods and with careful attention to side effects of any given intervention.

Les maladies cardiovasculaires (MCV) demeurent au tournant de ce siècle la principale cause de mortalité dans le monde. Parmi les facteurs de risque, l’hypercholestérolémie et l’obésité abdominale sont directement liées au développement précoce de l’athérosclérose. L’hypercholestérolémie familiale, communément associée à une déficience des récepteurs des lipoprotéines de basse densité (LDLR), est connue comme cause de maladie précoce d’athérosclérose et de calcification aortique chez l’humain. La subtilisine convertase proprotéine/kexine du type 9 (PCSK9), membre de la famille des proprotéines convertases, est trouvée indirectement associée aux MCV par son implication dans la dégradation du LDLR. Chez l'humain, des mutations du gène PCSK9 conduisent soit à une hypercholestérolémie familiale, soit à une hypocholestérolémie, selon que la mutation entraîne un gain ou une perte de fonction, respectivement. Il demeure incertain si les individus porteurs de mutations causant un gain de fonction de la PCSK9 développeront une calcification aortique ou si des mutations entraînant une perte de fonction provoqueront une obésité abdominale. Dans cette étude, nous avons examiné : 1) l’effet d’une surexpression de PCSK9 dans le foie de souris sur la calcification aortique ; 2) les conséquences d’une déficience en PCSK9 (Pcsk9 KO), mimant une inhibition pharmacologique, sur le tissu graisseux. Nous avons utilisé un modèle de souris transgénique (Tg) surexprimant le cDNA de PCSK9 de souris dans les hépatocytes de souris et démontrons par tomographie calculée qu’une calcification survient de façon moins étendue chez les souris PCSK9 Tg que chez les souris déficientes en LDLR. Alors que le PCSK9 Tg et la déficience en LDLR causaient tous deux une hypercholestérolémie familiale, les niveaux seuls de cholestérol circulant ne parvenaient pas à prédire le degré de calcification aortique. Dans une seconde étude, nous utilisions des souris génétiquement manipulées dépourvues de PSCK9 et démontrons que l’accumulation de graisses viscérales (adipogenèse) apparaît régulée par la PCSK9 circulante. Ainsi, en l’absence de PCSK9, l’adipogenèse viscérale augmente vraisemblablement par régulation post-traductionnelle des récepteurs à lipoprotéines de très basse densité (VLDLR) dans le tissu adipeux. Ces deux modèles mettent en évidence un équilibre dynamique de la PCSK9 dans des voies métaboliques différentes, réalisant un élément clé dans la santé cardiovasculaire. Par conséquent, les essais d’investigations et d’altérations biologiques de la PCSK9 devraient être pris en compte dans un modèle animal valide utilisant une méthode sensible et en portant une attention prudente aux effets secondaires de toute intervention. / Cardiovascular disease (CVD) is the leading cause of death in the 21st century. Among risk factors, hypercholesterolemia and abdominal obesity are directly linked to premature development of atherosclerosis. Familial hypercholesterolemia, commonly due to low-density lipoprotein receptor (LDLR) deficiency, is known to cause premature atherosclerosis and aortic calcification in humans. Proprotein convertase subtilisin/kexin 9 (PCSK9), a member of the proprotein convertase family, is indirectly associated with CVD through enhanced LDLR degradation. Mutations in the human PCSK9 gene lead to either familial hypercholesterolemia or hypocholesterolemia, depending on whether the mutation causes a gain or a loss of function, respectively. It is uncertain if individuals carrying mutations causing a gain-of-function of PCSK9 will develop aortic calcification or whether loss-of-function mutations will lead to abdominal obesity. In this thesis, we investigated: 1) the effect of PCSK9 overexpression on aortic calcification; 2) the consequences of PSCK9 deficiency, mimicking pharmacological inhibition of PCSK9 on fat tissue. We employed a transgenic (Tg) mouse model overexpressing mouse PCSK9 and illustrated by micro-computerized tomography that calcification occurs to a lesser extent in PCSK9 Tg mice than in LDLR-deficient mice. While both PCSK9 Tg and LDLR deficiency caused familial hypercholesterolemia, circulating cholesterol levels alone could not dictate the degree of aortic calcification. In another study, we used genetically modified mice lacking PCSK9 and demonstrated that visceral fat accumulation (adipogenesis) is regulated by circulating PCSK9. Thus in the absence of PCSK9, visceral adipogenesis increases likely via post-translational regulation of very-low-density lipoproteins receptors (VLDLR) in the adipose tissue. In conclusion, these two studies highlight the dynamic balance of PCSK9 in different metabolic pathways, making it a key element in cardiovascular health. Consequently, attempts to survey and/or alter PCSK9 biology should be performed in a valid animal model using sensitive methods and with careful attention to side effects of any given intervention.

Background Obesity, in particular abdominal adiposity, is associated with elevated fatty acids and pro-inflammatory adipokines, which are linked to ectopic fat storage and insulin resistance. During menopause, there is a redistribution of fat from the peripheral to abdominal depots. This transition is associated with an increased risk of type 2 diabetes and cardiovascular diseases. We hypothesized that a Paleolithic diet, with high proportions of lean meat, fish, vegetables, fruits, and oils, but devoid of dairy products and cereals, might have long-term beneficial effects on inflammation, fat metabolism, and circulating fatty acids. These effects might potentially reduce the risk of metabolic complications in postmenopausal women that are obese.  Methods Postmenopausal women with obesity were studied before, after six months, and after 24 months of one of two specified ad libitum diets. One diet was a Paleolithic diet, in which approximately 30% of the total energy (E%) was protein, 30 E% was fat, and 40 E% was carbohydrate. The other diet was a prudent control diet, consistent with Nordic Nutrition recommendations of 15 E% protein, 25 E% fat, and 55 E% carbohydrate. Dietary intakes of polyunsaturated fatty acids and protein were validated objectively by measuring circulating and urinary biomarkers. Anthropometrics and diet reports were analyzed, and abdominal subcutaneous fat samples were evaluated for the expression of proteins key in inflammation and fat metabolism and for lipoprotein lipase mass and activity. In addition, blood samples were analyzed to determine concentrations of specific serum proteins, serum lipids, and the fatty acids carried in cholesterol esters. Results The Paleolithic diet group reported reduced intakes of saturated fatty acids and carbohydrates and elevated intakes of protein and unsaturated fatty acids, compared to baseline. The elevated intakes of polyunsaturated fatty acids and protein were objectively verified for this group. After 24 months, both diets were found to have beneficial effects on the expression of inflammation-related genes in adipose tissue and pro-inflammatory factors in the circulation. Compared to the control group, the Paleolithic diet group exhibited more pronounced reductions of circulating cardiometabolic risk factors, including the ratio of triglycerides to high density lipoprotein, lipogenic index, specific fatty acids, and indices of desaturase activities. After six months, the Paleolithic group also exhibited more pronounced reductions in lipogenesis-promoting factors, including the expression of key proteins in fat synthesis, the activity of lipoprotein lipase, and the activity of stearoyl-CoA desaturase 1, compared to the control group. Conclusion Long-term weight loss in postmenopausal obese women was accompanied by reductions in low-grade inflammation in adipose tissue and in the circulation. In addition, a Paleolithic diet, with a high content of unsaturated fatty acids and a low content of refined carbohydrates, appeared to provide greater reductions in cardiometabolic risk factors associated with insulin resistance and lipogenesis, compared to a prudent control diet. / Bakgrund De senaste decennierna har förekomsten av övervikt och fetma ökat kraftigt i stora delar av världen. Detta beror på en kombination av olika faktorer såsom specifika gener vilka främjar fettinlagring, men kanske främst ett överintag av energirik mat i kombination med minskad fysisk aktivitet. Fetma och specifikt bukfetma, vilket tilltar hos kvinnor efter klimakteriet (postmenopausala), ökar risken för höjda blodfettsnivåer och låggradig inflammation, vilket kan leda till utveckling av typ 2-diabetes samt hjärt- och kärlsjukdomar. Kost och viktnedgång är avgörande för bibehållen hälsa och av stort intresse är att urbefolkningar runt om i världen har låg förekomst av fetma, diabetes, hjärt- och kärlsjukdom, troligtvis kopplat till olika livsstilsfaktorer som högre fysisk aktivitet samt kostfaktorer.  Syfte Vårt syfte var att undersöka metabola förändringar i fettväv och cirkulation hos postmenopausala kvinnor med fetma kopplat till en 24 månaders paleolitisk kostintervention. Den paleolitiska kosten, som ingick i studien består av en hög andel magert kött, fisk, grönsaker, frukt, nötter, oliv- och rapsolja och där mjölkprodukter och spannmål är uteslutna. Vår hypotes var att en paleolitisk kost med hög andel protein och omättade fettsyror har fördelaktiga långtidseffekter på inflammation, fettmetabolism och cirkulerande fettsyror jämfört med en kost baserad på Nordiska näringsrekommendationer med ett högt intag av kolhydrater. Metoder Postmenopausala kvinnor med fetma studerades före, vid sex månader och efter 24 månaders intag, utan energirestriktioner, av antingen en paleolitisk kost eller en kost enligt Nordiska näringsrekommendationer. Kroppsmätningar, kostregistreringar, genuttryck av nyckelproteiner i inflammation och fettmetabolism i fettväv samt koncentrationer av blodfetter, specifika proteiner och fettsyror bestämdes i plasma. Resultat I linje med rekommendationerna så rapporterade gruppen som åt den paleolitiska kosten ett minskat intag av mättat fett och kolhydrater samt ett ökat intag av protein och omättat fett jämfört med baslinjenivåerna. Det ökade intaget av fleromättade fettsyror och protein bekräftades med objektiva mätmetoder. Efter 24 månaders intervention uppvisade båda grupperna en jämförbar viktnedgång och en minskning av flertalet proinflammatoriska faktorer i såväl fettväv som i cirkulation. Den grupp som åt paleolitisk kost uppvisade en kraftigare reduktion av cirkulerande kardiometabola riskfaktorer som index för fettsyntes och desaturaser, specifika fettsyror samt kvoten triglycerider till HDL (high density lipoprotein). Efter sex månader bidrog den paleolitiska kosten också till en mer påtaglig minskning av faktorer involverade i fettinlagring, som uttryck av specifika nyckelproteiner i fettsyntes, aktivitet för lipoprotein lipas och stearoyl-CoA desaturase 1 index jämfört med kontrollkosten. Slutsatser En långvarig viktminskning hos postmenopausala kvinnor med fetma åtföljs av en minskad låggradig inflammation i fettväv och i cirkulation. En paleolitisk kost med hög andel omättade fettsyror och låga halt kolhydrater är kopplat till en kraftigare minskning av riskparametrar för insulinresistens och nyckelfaktorer för fettinlagring jämfört med en kontrollkost enligt Nordiska näringsrekommendationer.

Contexte : La dysfonction du tissu adipeux blanc (TAB) favorise les facteurs de risque de diabète de type 2 (DbT2), c’est-à-dire la résistance à l’insuline (RI), l’hyper sécrétion d’insuline glucostimulée (SIGS), le délai de clairance des gras et les concentrations élevées d’apoBlipoprotéines (apoB plasmatique) incluant les lipoprotéines de faible densité (LDL). De récentes études de notre laboratoire et d’autres suggèrent que le niveau élevé d’apoB plasmatique (hyperapoB) est une cause et non seulement une conséquence de la dysfonction du TAB. De plus, une internalisation augmentée d’apoB-lipoprotéines via les récepteurs tels que le récepteur aux LDLs (LDLR) et le cluster de différenciation 36 (CD36), favorise le risque de DbT2. Cependant, les mécanismes sous-jacents de même que les interventions nutritionnelles pour les cibler demeurent incertains. L'activation de la voie de l’inflammasome NLRP3/ interleukine (IL) -1β favorise la dysfonction du TAB et les facteurs de risque de DbT2 et est activée par les LDLs oxydées dans les cellules immunitaires. L'acide eicosapentaénoïque (AEP) et l'acide docosahexaénoïque (ADH) réduisent l'hyperapoB, l'activité de l’inflammasome NLRP3 dans les cellules immunitaires et les facteurs de risque de DbT2 chez l’humain. Ils sont synthétisés de façon endogène par l’entremise des désaturases d’acides gras δ-5 (D5D) et δ-6 (D6D). Chez l’humain, de faibles niveaux d’AEP et d’ADH circulants et d’activité de la D5D et une activité élevée de la D6D prédisent l'incidence de DbT2 et la RI par des mécanismes inconnus. Objectifs : L'hypothèse de ma thèse est que l'AEP et l’ADH améliorent les facteurs de risque de DbT2, soit la dysfonction du TAB, le délai de clairance des gras, la RI et l’hyper SIGS, ceci via une baisse de l'apoB plasmatique et de l’activité de l’inflammasome NLRP3 dans le TAB. Les objectifs sont d'examiner si: 1) les associations entre les activités de la D5D et de la D6D et les facteurs de risque de DbT2 dépendent de l'apoB plasmatique; 2) la supplémentation en AEP+ADH réduit l'apoB plasmatique, l'expression du LDLR et du CD36 dans le TAB, l'activité de l’inflammasome NLRP3 dans le TAB et les facteurs de risque de DbT2; 3) l’AEP+ADH inhibe la sécrétion d'IL-1β par le TAB humain stimulée par des signaux canoniques ou les LDLs natives. Méthodes: Des hommes et des femmes postménopausées normoglycémiques ont été testés à l’état basal et après une supplémentation en AEP (1,8 g/jour) et ADH (0,9 g/jour) de 12 semaines. Les activités de la D5D et de la D6D ont été estimées à partir des acides gras produits/précurseurs dans les phospholipides plasmatiques. Nous avons mesuré la SIGS, la RI et le disposition index lors d’un clamp Botnia. Après un repas à 66% de gras, le délai de clairance des gras a été mesuré par l’aire sous la courbe (sur 6 h) des triglycérides (TG) ou de l’apoB48 (chylomicrons) plasmatiques. Ex vivo dans une biopsie de TAB, nous avons mesuré l'expression de surface du LDLR et du CD36 par immunohistochimie, l'ARNm de NLRP3 et IL1B par RT-qPCR et la sécrétion d'IL-1β par alpha-LISA en l’absence ou en présence d’une stimulation par le lipopolysaccharide (LPS), l'adénosine triphosphate (ATP) et/ou les LDLs humaines natives et lors d’une co-incubation avec l’AEP+ADH. Résultats: À l’état basal (N=98), l'activité de la D5D corrélait négativement avec l'apoB plasmatique, la 2e phase de SIGS, la RI et le délai de clairance des chylomicrons et ces associations étaient dépendantes de l'apoB plasmatique. Inversement, l'activité de la D6D corrélait positivement avec la SIGS, la RI et le délai de clairance des chylomicrons indépendamment de l'apoB plasmatique. Chez les sujets ayant complété la supplémentation en AEP+ADH (N=30), on notait une amélioration de la 1e phase de SIGS, du disposition index et de la clairance des TGs. Des niveaux initiaux plus élevés d'apoB plasmatique, de TGs postprandiaux plasmatiques et de RI, et dans le TAB d'expression du LDLR et du CD36, de sécrétion d’IL-1β et d'ARNm de NLRP3 prédisaient une plus grande réduction de ces paramètres. En comparaison à l'acide palmitique, l’AEP+ADH inhibait la sécrétion d'IL-1β par le TAB, en l’abscence ou en présence d’une stimulation par le LPS, l'ATP et/ou les LDLs natives de ces sujets. Conclusion: Les associations inverses entre l'activité de la D5D avec les facteurs de risque de DbT2 sont dépendantes de l'apoB plasmatique. Les meilleurs répondants à la supplémentation en AEP et ADH, en termes de réduction d'apoB plasmatique, d’expression du LDLR et du CD36 dans le TAB, d'activité de l’inflammasome NLRP3 dans le TAB, de TGs postprandiaux et de RI, sont les sujets avec des niveaux initiaux élevés de ces paramètres. L’AEP et l’ADH inhibent directement la sécrétion d'IL-1β par le TAB humain induite par les LDLs natives ou d'autres signaux. Nous proposons que la supplémentation en AEP et ADH puisse cibler l'activité de l’inflammasome NLRP3 dans le TAB, induite par un niveau élevé d’apoB-lipoprotéines plasmatiques ou internalisées par les récepteurs, et ainsi aider à prévenir le DbT2. / Background: White adipose tissue (WAT) dysfunction promotes risk factors for type 2 diabetes (T2D), namely insulin resistance (IR), high glucose-stimulated insulin secretion (GIIS), delayed fat clearance and high concentrations of apoB-lipoproteins (measured as plasma apoB) including low density lipoproteins (LDL). Recent studies from our lab and others suggest that high plasma apoB (hyperapoB) is a cause and not only a consequence of WAT dysfunction. Moreover, upregulated receptor-mediated uptake of apoB-lipoproteins via LDL receptor (LDLR) and cluster of differentiation 36 (CD36), promotes the risk for T2D. However, underlying mechanisms as well as nutritional interventions to target them remain unclear. Activation of the NLRP3 inflammasome/interleukin (IL)-1β pathway promotes WAT dysfunction and risk factors for T2D and is activated by oxidized LDLs in immune cells. Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) reduce hyperapoB, NLRP3 inflammasome activity in immune cells and risk factors for T2D in humans. They are synthesized endogenously through δ-5 (D5D) and δ-6 (D6D) fatty desaturases. In humans, low levels of circulating EPA and DHA and D5D activity and high D6D activity predict the incidence of T2D and IR by unknown mechanisms. Objectives: The hypothesis of my thesis is that EPA and DHA improve T2D risk factors, namely WAT dysfunction, delayed fat clearance, IR and high GIIS, this via a reduction of plasma apoB and WAT NLRP3 inflammasome activity. The objectives are to examine whether: 1) the associations between the levels of D5D and D6D activities and the risk factors for T2D are dependent on plasma apoB; 2) supplementation with EPA+DHA reduces plasma apoB, WAT LDLR and CD36 expression, WAT NLRP3 inflammasome activity and T2D risk factors; 3) EPA+DHA directly inhibits IL-1β secretion from human WAT stimulated by canonical signals or native LDLs. Methods: Normoglycemic men and postmenopausal women were tested at baseline and after supplementation with EPA (1.8 g/day) and DHA (0.9 g/day) for 12 weeks. The activities of D5D and D6D were estimated from the product/precursor fatty acids in plasma phospholipids. We measured GIIS, IR and disposition index by a Botnia clamp. Following a 66% fat meal, delayed fat clearance was measured as the area under the curve (over 6 h) of plasma triglycerides (TG) or apoB48 (chylomicrons). Ex vivo in a WAT biopsy, we measured LDLR and CD36 surface expression by immunohistochemistry, NLRP3 and IL1B mRNA by RT-qPCR, and IL-1β secretion by alpha-LISA either unstimulated or stimulated by lipopolysaccharide (LPS), adenosine triphosphate (ATP), and/or native human LDLs, and during co-incubation with EPA+DHA. Results: At baseline (N=98), D5D activity correlated negatively with plasma apoB, 2nd phase GIIS, IR and delayed chylomicron clearance and these associations were dependent on plasma apoB. Conversely, D6D activity correlated positively with GIIS, IR, and delayed chylomicron clearance independently of plasma apoB. In subjects who completed the EPA+DHA supplementation (N=30), there was an amelioration in 1st phase GIIS, disposition index and TG clearance. Higher baseline levels of plasma apoB, plasma postprandial TGs, IR, WAT LDLR and CD36 surface expression, WAT IL-1β secretion and WAT NLRP3 mRNA predicted a greater reduction of these parameters. In comparison with palmitic acid, EPA+DHA inhibited IL-1β secretion from WAT, either unstimulated or stimulated by LPS, ATP and/or subjects’ native LDLs. Conclusion: The negative associations of D5D activity with risk factors for T2D are dependent on plasma apoB. Best responders to EPA and DHA supplementation to reduce plasma apoB, WAT LDLR and CD36 expression, WAT NLRP3 inflammasome activity, delayed TG clearance, and IR are subjects with elevated baseline levels of these parameters. EPA and DHA directly inhibit IL-1β secretion from human WAT induced by native LDLs or other signals. We propose that EPA and DHA supplementation may target upregulated WAT NLRP3 inflammasome activity induced by high plasma concentrations, or receptor-mediated uptake, of apoB-lipoproteins, and thus help prevent T2D.