Mediterranean Diet and the Metabolic Syndrome

This study has been completed.
Sponsor:
Information provided by:
Second University of Naples
ClinicalTrials.gov Identifier:
NCT00640783
First received: March 4, 2008
Last updated: March 19, 2008
Last verified: March 2008
  Purpose

The metabolic syndrome has been identified as a target for dietary therapies to reduce risk of cardiovascular disease; however, the role of diet in the etiology of the metabolic syndrome is poorly understood. To assess the effect of a Mediterranean-style diet on endothelial function and vascular inflammatory markers in patients with the metabolic syndrome

Randomized, single-blind trial conducted from June 2001 to January 2004 at a university hospital in Italy among 180 patients (99 men and 81 women) with the metabolic syndrome, as defined by the Adult Treatment Panel III.

Patients in the intervention group (n = 90) were instructed to follow a Mediterranean-style diet and received detailed advice about how to increase daily consumption of whole grains, fruits, vegetables, nuts, and olive oil; patients in the control group (n = 90) followed a prudent diet (carbohydrates, 50%-60%; proteins, 15%-20%; total fat, <30%).

After 2 years, patients following the Mediterranean-style diet consumed more foods rich in monounsaturated fat, polyunsaturated fat, and fiber and had a lower ratio of omega-6 to omega-3 fatty acids. Total fruit, vegetable, and nuts intake (274 g/d), whole grain intake (103 g/d), and olive oil consumption (8 g/d) were also significantly higher in the intervention group (P<.001). The level of physical activity increased in both groups by approximately 60%, without difference between groups. Mean body weight decreased more in patients in the intervention group (-4.0 kg) than in those in the control group (-1.2 kg) (P<.001). Compared with patients consuming the control diet, patients consuming the intervention diet had significantly reduced serum concentrations of hs-CRP (P = .01), IL-6 (P = .04), IL-7 (P = 0.4), and IL-18 (P = 0.3), as well as decreased insulin resistance (P<.001). Endothelial function score improved in the intervention group but remained stable in the control group. At 2 years of follow-up, 40 patients in the intervention group still had features of the metabolic syndrome, compared with 78 patients in the control group (P<.001).

A Mediterranean-style diet might be effective in reducing the prevalence of the metabolic syndrome and its associated cardiovascular risk.


Condition Intervention
Metabolic Syndrome
Behavioral: Mediterranean diet
Behavioral: Control

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Parallel Assignment
Masking: Single Blind (Outcomes Assessor)
Primary Purpose: Treatment
Official Title: Effect of a Mediterranean-Style Diet on Endothelial Dysfunction and Markers of Vascular Inflammation in the Metabolic Syndrome

Resource links provided by NLM:


Further study details as provided by Second University of Naples:

Primary Outcome Measures:
  • Endothelial function and vascular inflammatory markers [ Time Frame: 2 years ] [ Designated as safety issue: Yes ]

Secondary Outcome Measures:
  • Resolution of metabolic syndrome [ Time Frame: 2 years ] [ Designated as safety issue: Yes ]

Enrollment: 180
Study Start Date: June 2001
Study Completion Date: January 2004
Primary Completion Date: October 2003 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: 1
Mediterranean diet
Behavioral: Mediterranean diet
The dietary advice was tailored to each patient on the basis of 3-day food records. The recommended composition of the dietary regimen was as follows: carbohydrates, 50% to 60%; proteins, 15% to 20%; total fat, less than 30%; saturated fat, less than 10%; and cholesterol consumption, less than 300 mg per day. Moreover, patients were advised to consume at least 250 to 300 g of fruits, 125 to 150 g of vegetables, and 25 to 50 g of walnuts per day; in addition, they were also encouraged to consume 400 g of whole grains (legumes, rice, maize, and wheat) daily and to increase their consumption of olive oil.
Active Comparator: 2
Control diet
Behavioral: Control
Patients consuming the control diet were given general oral and written information about healthy food choices at baseline and at subsequent visits but were offered no specific individualized program. However, the general recommendation for macronutrient composition of the diet was similar to that for the intervention group (carbohydrates, 50%-60%; proteins, 15%-20%; and total fat, <30%).

Detailed Description:

Patients consuming the intervention diet were given detailed advice about the usefulness of the experimental diet. Through a series of monthly small-group sessions, intervention patients received education in reducing dietary calories (if needed), personal goal-setting, and self-monitoring using food diaries. Behavioral and psychological counseling was also offered. The dietary advice was tailored to each patient on the basis of 3-day food records. The recommended composition of the dietary regimen was as follows: carbohydrates, 50% to 60%; proteins, 15% to 20%; total fat, less than 30%; saturated fat, less than 10%; and cholesterol consumption, less than 300 mg per day. Moreover, patients were advised to consume at least 250 to 300 g of fruits, 125 to 150 g of vegetables, and 25 to 50 g of walnuts per day; in addition, they were also encouraged to consume 400 g of whole grains (legumes, rice, maize, and wheat) daily and to increase their consumption of olive oil. Patients were in the program for 24 months and had monthly sessions with the nutritionist for the first year and bimonthly sessions for the second year. Compliance with the program was assessed by attendance at the meetings and completion of the diet diaries.

  Eligibility

Ages Eligible for Study:   25 Years to 60 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

  • To be enrolled in the study, patients had to have 3 or more of the following criteria to meet the diagnosis of the metabolic syndrome, as defined by the Adult Treatment Panel III

Exclusion Criteria:

  • Patients were excluded if they had cardiovascular disease, psychiatric problems, a history of alcohol abuse (alcohol consumption 500 g/wk in the last year), if they smoked, or if they took any medication.
  Contacts and Locations
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Please refer to this study by its ClinicalTrials.gov identifier: NCT00640783

Locations
Italy
Department of Geriatrics and Metabolic Diseases
Naples, Italy, 80138
Sponsors and Collaborators
Second University of Naples
Investigators
Principal Investigator: Dario Giugliano, MD, PhD Department of Geriatrics and Metabolic Diseases
  More Information

Publications:
Responsible Party: Dario Giugliano, MD, PhD, Department of Geriatrics and Metabolic Diseases
ClinicalTrials.gov Identifier: NCT00640783     History of Changes
Other Study ID Numbers: DGMM/06/2000
Study First Received: March 4, 2008
Last Updated: March 19, 2008
Health Authority: Italy: Ethics Committee

Keywords provided by Second University of Naples:
Metabolic syndrome
Mediterranean diet
Inflammatory markers
Endothelial function

Additional relevant MeSH terms:
Syndrome
Metabolic Syndrome X
Disease
Pathologic Processes
Insulin Resistance
Hyperinsulinism
Glucose Metabolism Disorders
Metabolic Diseases

ClinicalTrials.gov processed this record on September 18, 2014