Effets de l'alimentation méditerranéenne sur le profil de risque cardiovasculaire chez l'homme et la femme

Tableau d’honneur de la Faculté des études supérieures et postdoctorales, 2010-2011Les résultats mitigés des études d'intervention évaluant l'impact d'un seul nutriment ou aliment sur le profil de risque cardiovasculaire ont contribué à l'intérêt de plus en plus grandissant pour les modes alimentaires complets en prévention des maladies cardiovasculaires. À ce sujet, l'alimentation méditerranéenne traditionnelle a été associée à maintes reprises à un risque plus faible de maladies cardiovasculaires et de mortalité suite à ces maladies. Toutefois, aucune étude contrôlée n'a comparé la réponse cardiovasculaire des hommes et des femmes suite à une intervention nutritionnelle basée sur le mode alimentaire méditerranéen et ce, même si certaines évidences suggèrent que les femmes répondent différemment des hommes à un changement alimentaire. L'objectif de ce mémoire de maîtrise est donc d'étudier les différences sexuelles par rapport aux changements du profil lipidique et d'autres variables métaboliques associées au risque cardiovasculaire en réponse à une intervention nutritionnelle isocalorique basée sur les principes de l'alimentation méditerranéenne

Impact of the traditional Mediterranean diet on the Framingham risk score and the metabolic syndrome according to sex

Background: The traditional Mediterranean diet (MedDiet) has been recognized as a food pattern with beneficial effects on cardiovascular health. However, even if sex-related differences in the cardiovascular response to diet have been previously highlighted, the existence of such differences in the impact of the MedDiet on the global cardiovascular risk has not been yet investigated. This study examined sex differences in the global cardiovascular impact of a 4-week isoenergetic controlled MedDiet using the Framingham risk score and the National Cholesterol Education Program (NCEP) metabolic syndrome criteria. Methods: This study included 38 men and 32 premenopausal women (24–53 years) who had slightly elevated low-density lipoprotein cholesterol (LDL-C) concentrations (between 3.4 and 4.9¿mmol/L) or total cholesterol-to-high-density lipoprotein cholesterol (HDL-C) ratios =5.0. Cardiovascular risk factors were measured before and after the controlled MedDiet. Results: A time effect (P=0.04) was found for the Framingham risk score, with both men and women showing a nonsignificant decrease in response to the MedDiet. No time effect was found for the prevalence of the metabolic syndrome and the number of metabolic syndrome criteria that were met by participants (P>0.05). However, a time effect was noted for the continuous metabolic syndrome score (P=0.008), with nonsignificant decreases in both men and women. No sex-by-time interaction was noted for any of variables studied (P>0.05). Conclusions: Results from this study suggest that the global cardiovascular impact of the MedDiet, as assessed by the Framingham risk score and metabolic syndrome criteria, is not significantly different in men than in premenopausal women in isoenergetic conditions

Gender differences in the effects of repeated taste exposure to the Mediterranean diet : a 6-month follow-up study

Objectif. Déterminer si une intervention basée principalement sur l'exposition au régime méditerranéen, accompagnée de recommandations et d'outils pour encourager une alimentation saine, mène à des effets différents en ce qui concerne l'adhésion au régime alimentaire et la gestion du poids six mois après l'intervention chez des femmes et des hommes canadiens. Méthodes. Trente-huit hommes et 32 femmes préménopausées (tous âgés de 24 à 53 ans) ont été exposés au même régime méditerranéen expérimental pendant 4 semaines au cours desquelles la nourriture leur était fournie. Les participants ont aussi reçu des recommandations et des outils pour les aider à adhérer à un régime alimentaire sain, sans autre contact jusqu'à la visite de suivi 6 mois plus tard. Résultats. En comparaison au début de l'étude, le score méditerranéen a augmenté à la fin du suivi de 6 mois (effet temps P = 0,003) sans différence entre les sexes (interaction entre le sexe et le temps P = 0,97). Concernant les composantes du score méditerranéen, on a observé des différences entre les sexes, les hommes déclarant des changements dans plus de groupes alimentaires que les femmes. Bien que l'intervention n'était pas axée sur la gestion du poids, en comparaison au début, l'IMC des participants a diminué au cours de l'intervention tant chez les hommes que chez les femmes. Cependant, seules les femmes ont maintenu un IMC plus bas 6 mois après l'intervention. Conclusions. L'exposition de courte durée au régime méditerranéen favorise l'adhésion à ce modèle alimentaire chez les deux sexes et aide à la gestion du poids, particulièrement chez les femmes.Purpose: To determine whether an intervention based mainly on exposure to the Mediterranean diet (MedDiet), along with recommendations/tools for encouraging healthy eating, lead to different effects on dietary adherence and body weight management six months post-intervention in Canadian men and women. Methods: Thirty-eight men and 32 premenopausal women (24-53 years) were exposed to the same 4-week experimental MedDiet during which all foods were provided to participants. Participants also received some recommendations/tools to adhere to a healthy way of eating, with no other contact until the 6-month follow-up visit. Results: Compared to baseline, the Mediterranean score (MedScore) had increased at the end of the 6-month follow-up (time effect P=0.003), with no gender difference (gender-by-time interaction P=0.97). Although our intervention was not focused on body weight management, compared to baseline, BMI decreased during the intervention in both men and women (respectively P<0.0001 and P=0.03); however, only the female participants of this study managed to maintain the lower BMI, six months after the intervention (P=0.03 for women; gender-by-time interaction P=0.04). Conclusions: Exposure to the MedDiet for a short duration promotes the adherence to this food pattern in both genders and helps in the management of body weight, especially in women

Effects of a dietary intervention promoting the adoption of a Mediterranean food pattern on fast-food consumption among healthy French-Canadian women

It is expected that a dietary intervention based on the traditional Mediterranean food pattern should be associated with a reduction in fast-food consumption but this has never been tested before. We assessed the impact of a 12-week dietary intervention, promoting the adoption of a Mediterranean food pattern, on fast-food consumption among seventy-one healthy women aged between 30 and 65 years. The dietary intervention consisted of two group sessions and seven individual sessions with a dietitian. To determine the Mediterranean dietary score (MedScore) and fast-food consumption, an FFQ was administered. During the 12-week intervention, the MedScore significantly increased (from 21·1 (SD 3·6) units at baseline to 28·6 (SD 4·4) units at week 12, P,0·0001), while the fast-food consumption significantly decreased (from 51·7 (SD 46·4) g/d at baseline to 20·5 (SD 18·2) g/d at week 12, P,0·0001). Moreover, women who had a higher consumption of fast food at baseline decreased their fast-food consumption to the most (r 20·50, P,0·0001). When four subgroups were formed on the basis of median values of Medscore and fast-food consumption changes, it was found that only the subgroup of women which increased the most their MedScore and decreased the most their fast-food consumption experienced a significant decrease in BMI (P,0·01). In conclusion, a dietary intervention promoting the Mediterranean food pattern led to a decrease in fast-food consumption among healthy women even if it was not a specific target of the intervention. Dietary strategies for increasing intake of healthy foods may be a useful approach for decreasing intake of less healthy foods

Sex differences in the impact of the Mediterranean diet on cardiovascular risk profile

The traditional Mediterranean diet (MedDiet) is now widely recommended in the prevention of CVD. However, it is not known whether the MedDiet has the same beneficial cardiovascular effects in women and in men. The objective of the present study was to investigate sex-related differences with regard to changes in cardiometabolic variables in response to a 4-week isoenergetic MedDiet. Participants were thirty-eight men and thirty-two premenopausal women aged between 25 and 50 years who had slightly elevated LDL-cholesterol (LDL-C) concentrations (3·4–4·9 mmol/l) or total cholesterol:HDL-cholesterol ratio = 5·0. A 4-week run-in period preceded the MedDiet in order to control the inter- and intra-individual variability. Cardiometabolic variables were measured before and after the MedDiet. Total cholesterol, LDL-C, apoB and apoA-1 plasma concentrations as well as diastolic blood pressure decreased (P < 0·05) in both men and women (respectively, 10, 10, 10, 6 and 5 % for men and 6, 7, 9, 4 and 4 % for women). ApoA-2 concentrations and insulin concentrations 2 h after the oral administration of 75 g of glucose demonstrated sex × time interactions (respectively, P = 0·05 and P = 0·03) and only men experienced a decrease for these variables (respectively, 8 and 25 %). In conclusion, consuming a MedDiet led to significant changes in plasma lipid profile in both men and women, while only men had significant improvements in insulin homeostasis. These results support the importance of investigating sex-related differences in response to diet in order to perhaps further individualise dietary guidelines in the prevention of CVD and type 2 diabetes

Sex differences in the impact of the Mediterranean diet on LDL particle size distribution and oxidation

Sex differences have been previously highlighted in the cardioprotective effects of the Mediterranean diet (MedDiet). The objective of this study was to investigate whether sex differences also exist with regard to LDL particle size distribution and oxidation. Participants were 37 men and 32 premenopausal women (24–53 years) with slightly elevated LDL-C concentrations (3.4–4.9 mmol/L) or total cholesterol/HDL-C =5.0. Variables were measured before and after a four-week isoenergetic MedDiet. Sex differences were found in response to the MedDiet for the proportion of medium LDL (255–260 Å) (p for sex-by-time interaction = 0.01) and small, dense LDL (sdLDL; <255 Å) (trend; p for sex-by-time interaction = 0.06), men experiencing an increase in the proportion of medium LDL with a concomitant reduction in the proportion of sdLDL, while an opposite trend was observed in women. A sex difference was also noted for estimated cholesterol concentrations among sdLDL (p for sex-by-time interaction = 0.03), with only men experiencing a reduction in response to the MedDiet. The MedDiet marginally reduced oxidized LDL (oxLDL) concentrations (p = 0.07), with no sex difference. Results suggest that short-termconsumption of the MedDiet leads to a favorable redistribution of LDL subclasses from smaller to larger LDL only in men. These results highlight the importance of considering sex issues in cardiovascular benefits of the MedDie

Sex differences in the impact of the Mediterranean diet on systemic inflammation

Background: Some intervention trials have reported a reduction in systemic inflammation with the Mediterranean diet (MedDiet) while others have observed no effect. Despite the fact that sex differences have been highlighted in the inflammatory regulation, it is still not known whether MedDiet exerts similar effects on systemic inflammation in men and women. The aim of this study was therefore to investigate sex differences in the effects of the MedDiet on high-sensitivity C-reactive protein (hs-CRP). Findings: Participants were 35 men and 27 premenopausal women (24–53 years) presenting a slightly deteriorated lipid profile. All foods were provided to participants during a 4-week isocaloric MedDiet. At baseline, women had higher hs-CRP concentrations than men (P¿=¿0.03). No sex difference was observed in hs-CRP response to the MedDiet (P for sex-by-time interaction¿=¿0.36), with both men and women experiencing no change (respectively P¿=¿0.62 and P¿>¿0.99). When subgroups were formed according to hs-CRP concentration before the MedDiet phase, men with elevated baseline values (=2 mg/l) experienced a reduction in hs-CRP over time with the MedDiet (-26.5 %) while an increase was observed in men with lower baseline values (+96.6 %; P for group-by-time interaction¿=¿0.02). This pattern of change was not observed in women. Conclusions: Results from this controlled feeding study suggest that men and women have similar effects from the MedDiet on systemic inflammation. The individual’s overall inflammatory status seems to influence these effects, but only in men

Effect of the Mediterranean diet on lipid and lipoprotein profile : is it influenced by the family history of dyslipidemia?

Background: A large inter-individual variability in the lipid-lipoprotein response to Mediterranean diet (MedDiet) has been highlighted in clinical studies. This variability may be attributed to multiple factors, including inherited genetic susceptibilities to dyslipidemia. The aim of the present study was to examine whether family history of dyslipidemia influences the lipid-lipoprotein response to the MedDiet. Design and Methods: We recruited 36 individuals with a positive family history of dyslipidemia (i.e. having at least one firstdegree relative with a diagnosis of dyslipidemia) and 28 individuals with a negative family history of dyslipidemia, aged between 24-53 years, who had slightly elevated LDL-C concentrations (3.4-4.9 mmol/l) or total cholesterol to HDL-&UDWLR Variables related to the lipid-lipoprotein profile were measured before and after a 4-week isocaloric MedDiet during which all foods and drinks were provided to participants. Results: A group by time interaction was noted for plasma total cholesterol concentrations (P=0.03), subjects with a negative family history of dyslipidemia having greater decreases than those with a positive family history of dyslipidemia (respectively -11.3% vs. -5.1%). Decreases in LDL-C, HDLC, total cholesterol to HDL-C ratio, LDL-C to HDL-C ratio, apolipoprotein (apo) B, apo A- 1, apo A-2 and apo B to apo A-1 ratio were also noted, with no difference between groups (P for group by time interaction ). No change was observed for triglyceride (TG) concentrations and TG to HDL-C ratio. Conclusions: Results highlight that inherited susceptibilities to dyslipidemia may explain at least in part the heterogeneity in the cholesterol-lowering effects of the MedDiet. (A

Effects of the traditional Mediterranean diet on adiponectin and leptin concentrations in men and premenopausal women : do sex differences exist?

Background/Objectives: Most of the interventional studies have investigated the impact of the diet on adiponectin and leptin concentrations only in men or in women. Consequently, it is still unknown whether the consumption of a healthy diet influences in a sex-specific manner these adipocytokines. We examined sex differences in the effects of the Mediterranean diet (MedDiet) on adiponectin and leptin concentrations, and determined whether changes in these adipocytokines are associated with changes in cardiovascular risk factors in both sexes. Subjects/Methods: Participants were 38 men and 32 premenopausal women (24–53 years) with slightly elevated low-density lipoprotein cholestrol concentrations (3.4–4.9¿mmol/l) or total cholesterol/high-density lipoprotein cholestrol (HDL-C)greater than or equal to5.0. Adiponectin, leptin and cardiovascular risk factors were measured before and after a 4-week fully controlled isoenergetic MedDiet. Results: Adiponectin concentration decreased in response to the MedDiet, but this decrease reached statistical significance only in men (P<0.001 for men and P=0.260 for women; sex-by-time interaction, P=0.072). Adjustments for body weight or waist circumference did not change results obtained. Changes in adiponectin were positively associated with concomitant variations in HDL-C in men (r=0.52, P=0.003) and with variations in apolipoprotein A-1 and insulin sensitivity as calculated by both the homeostasis model assessment index for insulin sensitivity and Cederholm indices in women (respectively, r=0.44, P=0.021; r=0.79, P<0.001 and r=0.47, P=0.020). The MedDiet had no impact on leptin and the leptin-to-adiponectin ratio in both sexes. Conclusions: Results suggest a sex difference in adiponectin response to the short-term consumption of the MedDiet, with only men experiencing a decrease. Also sex-specific patterns of associations between changes in adiponectin concentration and changes in cardiovascular risk factors were observed

Sex-Related Differences in the Effects of the Mediterranean Diet on Glucose and Insulin Homeostasis

Objective. To document sex differences in the impact of the Mediterranean diet (MedDiet) on glucose/insulin homeostasis and to verify whether these sex-related effects were associated with changes in nonesterified fatty acids (NEFA). Methods. All foods were provided to 38 men and 32 premenopausal women (24–53 y) during 4 weeks. Variables were measured during a 180 min OGTT before and after the MedDiet. Results. A sex-by-time interaction for plasma insulin iAUC was found (men: −17.8%, P=0.02; women: +9.4%, P=0.63; P for sex-by-time interaction = 0.005). A sex-by-time interaction was also observed for insulin sensitivity (Cederholm index, P=0.03), for which only men experienced improvements (men: +8.1%, P=0.047; women: −5.9%, P=0.94). No sex difference was observed for glucose and C-peptide responses. Trends toward a decrease in NEFA AUC (P=0.06) and an increase in NEFA suppression rate (P=0.06) were noted, with no sex difference. Changes in NEFA were not associated with change in insulin sensitivity. Conclusions. Results suggest that the more favorable changes in glucose/insulin homeostasis observed in men compared to women in response to the MedDiet are not explained by sex differences in NEFA response. This clinical trial is registered with clinicaltrials.gov NCT01293344