Étude des mécanismes responsables des effets bénéfiques de la diète Méditerranéenne, avec et sans perte de poids, chez des hommes avec le syndrome métabolique

Authors: Richard, Caroline
Advisor: Lamarche, BenoîtCouture, Patrick
Abstract: Metabolic syndrome (MetS) is a cluster of metabolic perturbations that predisposes to the development of cardiovascular disease (CVD). Scientific evidence increasingly suggests that adherence to the Mediterranean diet (MedDiet) improves several components of MetS and decreases the incidence of cardiovascular events. However, it is unclear why the MedDiet reduces the risk of CVD and what are the mechanisms underlying this beneficial effect. Moreover, studies have shown that adherence to the MedDiet is associated with weight loss which is a major confounding factor. So far, the impact of the MedDiet per se, i.e. without weight loss, on the main components of MetS is unknown. This thesis presents study results for which the main objective was to investigate the mechanisms by which the MedDiet, with and without weight loss, reduces the risk of CVD in men with MetS. Several components of the metabolism were studied in order to determine the mechanisms underlying the favorable impact of the MedDiet on features of MetS. The extent to which body weight reduction maximizes the impact of the MedDiet on these CVD risk factors was also studied. Altogether, data from this study revealed that consumption of the MedDiet, even without weight loss, beneficially modified lipid metabolism except for HDL (high-density lipoprotein) in men with MetS. The MedDiet led to a reduction in plasma LDL-apoB (low-density lipoprotein-apolipoprotein B) concentrations, which was mainly attributable to an increase in the clearance rate of LDL particles. The MedDiet without weight loss was also associated with reductions in the proportion of small, dense LDL particles and plasma concentrations of C-reactive protein. However, the MedDiet without weight loss had no beneficial effect on adipokines and pro-inflammatory cytokines derived from adipose tissue as well as concentrations of cell adhesion molecules; weight loss is required to improve these components of MetS. Thus, the beneficial effect of the MedDiet, irrespective of weight loss, on CVD risk is mainly due to an improvement in apoB metabolism and a lower systemic inflammation. Overall, weight loss has little additional impact on lipid metabolism except that of HDL particles.
Document Type: Thèse de doctorat
Issue Date: 2013
Open Access Date: 19 April 2018
Permalink: http://hdl.handle.net/20.500.11794/24659
Grantor: Université Laval
Collection:Thèses et mémoires

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