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Effect of the Mediterranean Diet on Lung Function in Smokers Without Previous Respiratory Disease

MEDISTAR STUDY: Mediterranean Diet and Smoking in Tarragona and Reus

Status
Completed
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT03362372
Acronym
MEDISTAR
Enrollment
566
Registered
2017-12-05
Start date
2017-06-01
Completion date
2020-07-01
Last updated
2023-03-14

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Lung Diseases

Brief summary

Several studies have shown the influence of the eating pattern on lung function. However, the benefits of the Mediterranean diet (DiMet) in preventing pulmonary dysfunction are not well known. Objective: To evaluate the effect of adherence to DiMet on the deterioration of lung function in smokers. Methodology: Design: Controlled, parallel, multicenter, cluster-randomized clinical trial. Participants: 566 active smokers with a cumulative consumption of more than 10 packets a year, within 25 to 75 year-old age group, without previous respiratory disease and who agree with the conditions of the study and sign an informed consent . Scope: 20 Primary Care Centers managed by the Catalan Health Institutes in Tarragona that will be randomly assigned to a control or an intervention group (1: 1). Intervention: During 2 years a nutritional intervention will be carried out to increase adherence to DiMet based on: 1) annual visit of personalized nutritional education, 2) annual telephone contact for intervention reinforcement, and 3) computer access to a dietary block designed ad hoc. The control group will follow their usual diet style. All participants will receive advice to quit smoking. It will be evaluated: a) pulmonary function by forced spirometry and b) adherence to the DiMet with a questionnaire of 14 items and biological determinations. Statistical analysis: For intention to treat. The unit of analysis will be the individual smoker. Parameters of pulmonary function and adherence to the DiMet of both groups will be compared. Expected results: DiMet prevents the appearance of altered lung function in smokers without previous respiratory pathology. Thus, DiMet will be key in pulmonary prevention, together with the fundamental recommendation of smoking cessation.

Detailed description

Several studies have shown the influence of the eating pattern on lung function. However, the benefits of the Mediterranean diet (DiMet) in preventing pulmonary dysfunction are not well known. Objective: To evaluate the effect of adherence to DiMet on the deterioration of lung function in smokers. Methodology: Design: Controlled, parallel, multicenter, cluster-randomized clinical trial. Participants: 566 active smokers with a cumulative consumption of more than 10 packets a year, within 25 to 75 year-old age group, without previous respiratory disease and who agree with the conditions of the study and sign an informed consent . Scope: 20 Primary Care Centers managed by the Catalan Health Institutes in Tarragona that will be randomly assigned to a control or an intervention group (1: 1). Intervention: During 2 years a nutritional intervention will be carried out to increase adherence to DiMet based on: 1) annual visit of personalized nutritional education, 2) annual telephone contact for intervention reinforcement, and 3) computer access to a dietary block designed ad hoc. The control group will follow their usual diet style. All participants will receive advice to quit smoking. It will be evaluated: a) pulmonary function by forced spirometry and b) adherence to the DiMet with a questionnaire of 14 items and biological determinations. Statistical analysis: For intention to treat. The unit of analysis will be the individual smoker. Parameters of pulmonary function and adherence to the DiMet of both groups will be compared. Expected results: DiMet prevents the appearance of altered lung function in smokers without previous respiratory pathology. Thus, DiMet will be key in pulmonary prevention, together with the fundamental recommendation of smoking cessation.

Interventions

The participants of the intervention CAP will enter into an educational program to increase adherence to the DiMet that will integrate three operational components: 1. Explain the particularities of DiMet and the benefits of its monitoring. It will be an individual visit of 25-30 minutes (V1) where the study variables will be collected and the medical tests will be performed and repeated annually for two years (V3 and V5). 2. Clarify the doubts of the DiMet monitoring and the advice received. It will be a telephone visit to reinforce the intervention, with annual frequency, for two years (V2 and V4). 3. Report on DiMet's own foods, cooking habits, adapted recipes and other related topics. It will be for access to an ad hoc designed nutrition blog.

Sponsors

Preventive Services and Health Promotion Research Network
CollaboratorOTHER
Fundacio d'Investigacio en Atencio Primaria Jordi Gol i Gurina
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
NONE

Intervention model description

Controlled, parallel, multicenter, cluster-randomized clinical trial.

Eligibility

Sex/Gender
ALL
Age
25 Years to 75 Years
Healthy volunteers
Yes

Inclusion criteria

* Active smoking and cumulative consumption ≥10 pack-years. * Age between 25-75 years. * Internet connection.

Exclusion criteria

* History of respiratory disease. * Chronic or terminal disorder that alters basal parameters. * Any reason that limits follow up.

Design outcomes

Primary

MeasureTime frameDescription
Change in lung function values in smokers without previous respiratory disease2 yearsChanges in lung function measured by spirometry. An altered lung function was considered if values of FVC \<80% and / or FEV1 \<80% and / or FEV1 / FVC \<0.7

Secondary

MeasureTime frameDescription
Nutritional intervention2 yearsThe effectiveness of the intervention will be measured by dietary changes by a food frequency questionnaire
Anthropometric parameters2 yearsChanges in anthropometric parameters: weight in kilograms and height in meters. Weight and height will be combined to report BMI in kg/m2
Changes in food consumption markers2 yearsChanges in food consumption markers: excreted of total polyphenols in fresh urine.
Changes in inflammation markers2 yearsChanges in serum inflammation markers: high-sensitivity C-reactive protein

Countries

Spain

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026