Effects of the Mediterranean Diet on Cardiovascular Risk Profile in Men and Women

Study Overview
=================
Brief Summary
-----------------
The purpose of this study is to document differences between men and women in changes in metabolic variables associated with cardiovascular risk in response to a 4 weeks isocaloric controlled nutritional intervention based on the Mediterranean diet in which all foods and drinks are provided to subjects. The investigators hypothesize that the decrease in LDL-cholesterol will be more important in men than in women.

Detailed Description
-----------------
Nutritional interventions promoting the adoption of the traditional Mediterranean diet (MedDiet) are known to have significant and beneficial effects on cardiovascular disease (CVD) risk profile. On the other hand, recent evidence suggests that women respond differently to diet than men. No study has yet compared men and women metabolic response to the MedDiet in a controlled metabolic context in which all foods and drinks consumed are provided to the participant prepared by the research team. Therefore, we do not know whether being fed a MedDiet in controlled conditions would have similar health benefits in men and women. The purpose of this study is to document differences between men and women in changes in metabolic variables associated with cardiovascular risk in response to a 4 weeks isocaloric controlled nutritional intervention based on the MedDiet in which all foods and drinks are provided to subjects. We hypothesize that the decrease in LDL-cholesterol will be more important in men than in women. In this parallel controlled trial, both men and women are assigned to the same 4 weeks experimental diet formulated to be concordant with characteristics of the traditional MedDiet. Data will be collected before and after the controlled nutritional intervention based on the MedDiet.

Official Title
-----------------
Gender Differences in Response to the Mediterranean Diet

Conditions
-----------------
Cardiovascular Diseases

Intervention / Treatment
-----------------
* Other: Controlled nutritional intervention based on the Mediterranean diet
* Other: Controlled nutritional intervention based on the Mediterranean diet


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Men and premenopausal women from de Quebec City metropolitan area. Slightly elevated LDL-cholesterol concentrations (3.4-4.9 mM) or total cholesterol to HDL-C ratio ≥ 5.0 At least one of the four following factors of the metabolic syndrome: 1) waist circumference > 94 cm in men and > 80 cm in women; 2) TG > 1.7 mmol/L; 3) fasting glycemia between 6.1 and 6.9 mmol/L and 4) blood pressure concentrations ≥ 130 / 85 mm Hg. Age: between 25 to 50 years Stable body weight (+/- 2.5 kg) for at least 3 months before the beginning of the study In women, a regular menstrual cycle for the last 3 months Exclusion Criteria: Subjects with endocrine disorders, cardiovascular events, type 1 or 2 diabetes and those using medication that could affect dependent variables measured (namely lipid-lowering, hypoglycemic, insulin sensitizers and anti hypertensive medication) Smokers Subjects with history of alcoholism Subjects with food allergies or food aversion that could impede compliance to the Mediterranean diet Pregnant women and those using systemic hormonal contraceptives

Ages Eligible for Study
-----------------
Minimum Age: 25 Years
Maximum Age: 50 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Prevention
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Men and Mediterranean diet<br>Men who are assigned to a 4 weeks experimental diet formulated to be concordant with characteristics of the traditional Mediterranean diet. | Other: Controlled nutritional intervention based on the Mediterranean diet<br>* Men are assigned to a 4 weeks isocaloric controlled nutritional intervention based on the Mediterranean diet (MedDiet) in which all foods and drinks are provided. The respective percentages of kcal derived from lipids, carbohydrates, protein and alcohol are respectively of 32%, 48%, 15% and 5%. Habitual energy intake of each participant is established by averaging energy requirements estimated by a validated food-frequency questionnaire (FFQ) and energy needs as determined by the Harris-Benedict formula. Body weight is measured on weekdays and total energy provided is revised if necessary for minimizing body weight fluctuations. This intervention period is preceded by a 4 weeks uncontrolled run-in period based on the Canada's Food Guide.<br>|
| Experimental: Women and Mediterranean diet<br>Women who are assigned to a 4 weeks experimental diet formulated to be concordant with characteristics of the traditional Mediterranean diet. | Other: Controlled nutritional intervention based on the Mediterranean diet<br>* Women are assigned to the same intervention than men in order to compare men and women metabolic response to the MedDiet.<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Cardiometabolic outcomes | Total cholesterol, LDL-cholesterol, HDL-cholesterol, triglycerides, apolipoprotein (apo) B, apo A-1 and apo A-2 plasma concentrations, systolic and diastolic blood pressure, glucose and insulin concentrations during a 180-min oral glucose tolerance test, insulin sensitivity, CRP and Interleukine-6 levels, oxidized-LDL, E-selectin, ICAM-1 and VCAM-1. | At baseline (at the beginning of the intervention) and at the end of the intervention period (4 weeks). | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Nutritional variables | Dietary intakes | At baseline (at the beginning of the intervention), at the end of the intervention period (4 weeks) and at 6-months post-intervention (28 weeks). | 
| Eating behaviors | Restraint, disinhibition, and susceptibility to hunger | At baseline (at the beginning of the intervention) and at the end of the intervention period (4 weeks) | 
| Appetite ratings | Desire to eat, hunger, fullness, and prospective food consumption | At baseline (at the beginning of the intervention) and at the end of the intervention period (4 weeks) | 
| physical activity habits | Weekly questionnaire about physical activities, a validated 3-day physical activity record (two weekdays and one weekend day) | At baseline (at the beginning of the intervention) and at the end of the intervention period (4 weeks) | 
| Anthropometric measurements | Height, weight, body mass index, waist and hip circumferences, | At baseline (at the beginning of the intervention), at the end of the intervention period (4 weeks) and at 6-months post-intervention (28 weeks) | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Cardiovascular diseases, Controlled nutritional intervention, Sex differences, Women, Men, Cardiovascular risk, Lipid profile, Blood pressure, Insulin sensitivity, Inflammatory markers, Endothelial function, Oxidative stress