Assessment lipophilic micronutrient status in obesity : relationship with inflammation and insulin resistance

L’obésité s’accompagne d’un état inflammatoire chronique qui joue un rôle délétère.Cet état associé à l’obésité été impliqué dans le développement de complications métaboliques:insulino-résistance et DT2.Chez les obèses,le TA est un site de production de médiateurs pro et/ou anti-inflammatoires, des adipokines.Les modifications et changements de style de vie et les approches thérapeutiques sont privilégiés pour lutter contre l’obésité.Toutefois,les approches préventives ne doivent pas être négligées,des études épidémiologiques ont mises en évidence une corrélation entre obésité et carence en micronutriments.Par ailleurs,il existe une corrélation inverse entre micronutriments lipophiles et caroténoïdes et la prévalence de l’obésité et du DT2.Le but de cette thèse est de comprendre le lien qui existe entre carence en micronutriments,obésité et complications associés.Une étude clinique transversale a été réalisée chez des obèses non diabétiques.Les résultats nous ont permis de montrer qu’il existe une association positive entre b-carotène et sensibilité à l'insuline chez l'obèse,effet pouvant être lié à une modulation de l'expression de certaines adipokines dont l'adiponectine qui est indépendamment associée à la concentration plasmatique en b-carotène.Une étude préclinique a été menée, dont l'objectif évaluer l'impact de la teneur en vitamines alimentaires sur la prise de poids et l'insulino-sensibilité.Des souris ont été soumises à un régime hypovitaminé.A 10 semaines,ce régime favorise la prise de masse grasse,modifie la sensibilité à l'insuline,en agissant au niveau du métabolisme lipidique hépatique,via une diminution des capacités oxydatives.Obesity is associated with chronic inflammatory condition that plays a deleterious role.This inflammatory state associated with obesity was involved in the development of metabolic complications : insulin resistance and T2DM.Obese, AT is a site for the production of pro and/or anti-inflammatory adipokines, and plays a major role in the development of chronic inflammation associated with obesity.Modifications and changes in lifestyle and therapeutic approaches are preferred to deal with obesity. However,preventive approaches should not be ignored,several epidemiological studies have shown a correlation between obesity and micronutrient deficiency.In addition,there is an inverse correlation between lipophilic micronutrients and carotenoids and the prevalence of obesity and T2DM.The purpose of this thesis is to understand the possible link between LM and carotenoids deficiency, obesity and associated physiological disorders.A cross-sectional study was performed in non-diabetic obese patients.The results allowed us to conclude the existence of a favorable effect of b-carotene on insulin sensitivity in obese patients.This effect may be related to modulation of inflammation or the expression of some adipokines(such as adiponectin), either directly or through its pro-vitamin A activity.A preclinical study was performed; the objective is to assess the impact of the vitamins on weight gain and insulin sensitivity.Mice were subjected to a hypovitaminic diet.After 10 weeks of regimen, we observed an increased adiposity and an altered insulin sensibility.This diet probably acts on the hepatic lipid metabolism via a decrease in oxidative capacity

Multivitamin restriction increases adiposity and disrupts glucose homeostasis in mice

International audienceA strong association between obesity and low plasma concentrations of vitamins has been widely reported; however, the causality of this relationship is still not established. Our goal was to evaluate the impact of a multivitamin restriction diet (MRD) on body weight, adiposity and glucose homeostasis in mice. The mice were given a standard diet or a diet containing 50 % of the recommended vitamin intake (MRD) for 12 weeks. At the end of the experiment, total body weight was 6 % higher in MRD animals than in the control group, and the adiposity of the MRD animals more than doubled. The HOMA-IR index of the MRD animals was significantly increased. The adipose tissue of MRD animals had lower expression of mRNA encoding adiponectin and Pnpla2 (47 and 32 %, respectively) and 43 % higher leptin mRNA levels. In the liver, the mRNA levels of Ppar alpha and Pgc1 alpha were reduced (29 and 69 %, respectively) in MRD mice. Finally, the level of beta-hydroxybutyrate, a ketonic body reflecting fatty acid oxidation, was decreased by 45 % in MRD mice. Our results suggest that MRD promotes adiposity, possibly by decreasing adipose tissue lipolysis and hepatic beta-oxidation. These results could highlight a possible role of vitamin deficiency in the etiology of obesity and associated disorders

Independent positive association of plasma beta-carotene concentrations with adiponectin among non-diabetic obese subjects

International audienceMany epidemiological studies find an inverse correlation between carotenoids intake or carotenoids plasma concentrations and body mass index (BMI), insulin resistance or metabolic syndrome in the general population. However, it is not clear whether these relationships occur in obese population. We conducted a cross-sectional study in 108 obese non-diabetic patients. There was an inverse correlation between plasma levels of pro-vitamin A carotenoids (alpha-carotene, beta-carotene and beta-cryptoxanthin) and both BMI and insulin resistance (estimated by the HOMA-IR). No correlation between plasma concentrations of lycopene or lutein/zeaxanthin and BMI or insulin resistance was found. The inverse association between the three pro-vitamin A carotenoids and HOMA-IR disappeared after adjustment for BMI and waist circumference. Interestingly, we identified a positive association between concentrations of beta-carotene and adiponectin in plasma that was independent of sex, age, smoking status, BMI and waist circumference. To our knowledge, such association has never been described in obese patients. These results suggest the existence of a favourable effect of beta-carotene on insulin sensitivity in obese individuals that could involve a positive regulation of adiponectin, either directly or via its pro-vitamin A activity. The demonstration of the potential benefits of beta-carotene towards insulin sensitivity would open the way to dietary strategies to prevent metabolic syndrome

Multivitamin restriction increases adiposity and disrupts glucose homeostasis in mice

A strong association between obesity and low plasma concentrations of vitamins has been widely reported; however, the causality of this relationship is still not established. Our goal was to evaluate the impact of a multivitamin restriction diet (MRD) on body weight, adiposity and glucose homeostasis in mice. The mice were given a standard diet or a diet containing 50 % of the recommended vitamin intake (MRD) for 12 weeks. At the end of the experiment, total body weight was 6 % higher in MRD animals than in the control group, and the adiposity of the MRD animals more than doubled. The HOMA-IR index of the MRD animals was significantly increased. The adipose tissue of MRD animals had lower expression of mRNA encoding adiponectin and Pnpla2 (47 and 32 %, respectively) and 43 % higher leptin mRNA levels. In the liver, the mRNA levels of Pparα and Pgc1α were reduced (29 and 69 %, respectively) in MRD mice. Finally, the level of β-hydroxybutyrate, a ketonic body reflecting fatty acid oxidation, was decreased by 45 % in MRD mice. Our results suggest that MRD promotes adiposity, possibly by decreasing adipose tissue lipolysis and hepatic β-oxidation. These results could highlight a possible role of vitamin deficiency in the etiology of obesity and associated disorders. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s12263-014-0410-x) contains supplementary material, which is available to authorized users

Similar 5-year HCC occurrence in Tenofovir- and Entecavir-treated HBV chronic infection in the French AFEF/ANRS CO22 Hepather cohort.

International audienceBackground: Chronic hepatitis B virus (HBV) infection results in a high risk of cirrhosis and its complications, cirrhosis decompensation (DC), hepatocellular carcinoma (HCC), liver transplantation (LT), death or any of these outcomes (composite endpoint [CE]). Nucleos(t)ide analogues (NUCs) such as tenofovir or entecavir are associated with a reduction in these complications.Aim: To compare the impact of tenofovir and entecavir on these outcomes in patients treated for HBV infection and included in the prospective Hepather cohort.Methods: All patients with HBV infection who had received tenofovir or entecavir for more than 6 months at or after entry in the ANRS CO22 cohort were selected. Patients with HDV and HCV co-infection or prior liver event were excluded. Incidence rates of events were compared using inverse probability of treatment weighting (IPW).Results: The cohort included 1800 patients (986 tenofovir and 814 entecavir). Median follow-up was 4.2 years. The incidences of HCC, DC, LT, ACD, LRD and CE were not different between tenofovir- (1.8 (0.9; 3.2), 0.6 (0.2; 1.6), 0.2 (0.0; 0.8), 1.7 (0.8; 3.0), 0.8 (0.2, 1.8) and 4.1 (3.0; 5.4) per 1000 person-years) and entecavir-treated patients (1.6 (0.7; 3.0), 0.7 (0.2; 1.8), 0.2 (0.0; 1.0), 3.0 (1.7, 4.8), 0.5 (0.1; 1.5) and 5.0 (3.3; 7.2)) per 1000 person-years, respectively.Conclusion: The risk of liver-related events or death was not different between tenofovir- and entecavir-treated patients in this large prospective cohort of predominantly non-cirrhotic French patients.Trial registration number: NCT019553458

Early Hepatocellular Carcinoma Detection Using Magnetic Resonance Imaging Is Cost-Effective in High-Risk Patients with Cirrhosis

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