Mediterranean Diet and the Metabolic Syndrome
Condition: Cardiovascular Disease
MeSH terms: Cardiovascular Diseases; Metabolic Syndrome
Study type: Interventional

Summary: 
      While there is now undisputable evidence relating elevated plasma low-density lipoprotein
      (LDL) cholesterol levels to an increased risk of coronary heart disease (CHD), it is being
      increasingly recognized that a significant proportion of CHD events occur in individuals
      characterized by a cluster of additional metabolic and physiological perturbations now
      defined as the metabolic syndrome. Epidemiological and clinical evidence have shown us that
      nutritional factors, often in conjunction with obesity, play a pivotal role in the
      pathophysiology of the metabolic syndrome. In that regard, accumulating evidence suggest that
      a Mediterranean-style diet (MedDiet) may beneficially modify several components of the
      metabolic syndrome including plasma triglycerides (TG) and high-density lipoprotein (HDL)
      cholesterol levels, insulin resistance, waist circumference and markers of vascular
      inflammation. However, the physiological mechanisms underlying the cardioprotective effects
      of the MedDiet on features of the metabolic syndrome and the importance of body weight
      reduction in maximizing these effects represent key issues that have yet to be investigated.

      The general objective of the study is to investigate for the first time in a controlled
      feeding study the mechanisms and factors underlying the impact of the MedDiet, with and
      without weight loss on the dyslipidemic features of the metabolic syndrome.
    

Detailed description: 
      The study has a duration of 35 weeks for each participant. Subjects will be first assigned to
      a North American control diet that they will consume for five weeks under isocaloric,
      weight-maintaining conditions. Participants will then consume the MedDiet for 5 weeks, again
      under isocaloric, weight-maintaining conditions. All foods will be provided to participants
      during these consecutive 5-week diets. Participants subsequently will then undergo a 20-week
      weight loss period in free-living conditions during which they will be given advice on how to
      create a 500 kcal deficit in their daily energy intake. The last phase of the study consists
      of a second 5-week MedDiet consumed under feeding, weight stabilizing conditions. Metabolic
      studies and CHD risk factor assessment will be performed at the end of each experimental
      diets. Metabolic studies include the measurement of in vivo kinetics of apolipoprotein
      (apo)B-containing lipoproteins including small dense LDL, apoCIII, HDL (apoAI) and C-reactive
      protein (CRP) as well as indirect measures of cholesterol absorption and synthesis.
    

Intervention name(s): isocaloric diet; free living conditions
Intervention type(s): Other; Other
Other intervention name(s): 3 isocaloric die; weight lost free living conditions
Allocation: Non-Randomized
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Prevention
Keywords: Metabolic syndrome; Mediterranean diet; Blood lipids; Coronary heart disease; Apolipoprotein