Dietary Intake in Adults From the GA2LEN Folow-up Survey

Study Overview
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Brief Summary
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The Nutrition Study of the GA2LEN Follow-Survey was designed to investigate the association between usual dietary intake and allergic and respiratory outcomes in adults across Europe. Within this framework, a food frequency questionnaire (FFQ) was designed to ascertain usual dietary intake of 250 food items, which was translated into the languages of the participant centres. Information on daily intake of foods, nutrients, and flavonoids was derived.

Detailed Description
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Within the GA2LEN Follow-up Survey, the Nutrition Survey was aimed at assessing dietary intake in adults across European countries and its association with various outcomes of allergy and respiratory health. In absence of an internationally comparable dietary questionnaire to ascertain usual dietary intake, a single and standardized food frequency questionnaire (FFQ) was design to be used as a common instrument in all participant countries. The FFQ is comprised of 32 food sections and 250 food items. The FFQ sections were designed following the recommendations by the EFCOSUM Group, which facilitate international comparisons of dietary intake. It also included several staple foods to capture locally representative dietary intake. Participants reported how often they had consumed each of the foods over the previous month, using eight predefined options (rarely or never, 1-3 times per month, once, 2-4, or 5-6 times per week, once, 2-3 times per day). Standard food portion sizes were used to quantify the intake following the recommendations from the UK's Food Standards Agency. Daily intake of foods (g) were estimated and macro- and micronutrient and flavonoid intakes were derived. The GA2LEN FFQ was validated in five EU countries, namely Finland, UK, Portugal, Germany, Poland, and Greece, and demonstrated to be a good tool to assess mid-term intake of foods, specifically essential polyunsaturated fatty acids (PUFAs). The instrument has also been demonstrated to be an accurate tool to assess dietary sources of flavonoids. Various approaches were planned to derive dietary exposures and to examine their association with respiratory and allergic outcomes. These included the use of dietary patterns derived from Principal Component Analysis (PCA), a dietary inflammatory index (DII), as well as single antioxidants, and individual food items.

Official Title
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Dietary Intake, Allergy and Respiratory Diseases in European Adults From the GA2LEN Follow-up Survey

Conditions
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Asthma, Lung Function Decreased, Food Allergy, Allergic Sensitisation, Allergic Rhinitis, COPD, Atopy

Intervention / Treatment
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* Other: Dietary intake of various nutrients, foods and biocompounds


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Participants aged 15-75 years old, who had responded to the GA2LEN Baseline survey and who met the definition of cases or controls (as described below) Exclusion Criteria: Participants who did not answer the baseline survey

Ages Eligible for Study
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Minimum Age: 15 Years
Maximum Age: 75 Years

Sexes Eligible for Study
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All

Study Plan
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How is the study designed?
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Arms and Interventions

| Intervention/Treatment |
| --- |
|Other: Dietary intake of various nutrients, foods and biocompounds|Participants answered a self-administered FFQ, in which they reported the usual frequency of intake of a list of 250 food items|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Asthma score | Five questions on symptoms in the last 12 months (breathless when wheezing, woken with tightness in chest, shortness of breath while at rest, shortness of breath after exercise, woken by shortness of breath) were used to construct an asthma symptom score on a five-point scale | Last 12 months | 
| Chronic rhinosinusitis (CRS) | defined following the EP3OS criteria, that is, the presence of at least two of the following symptoms for at least 12 weeks in the past year: (i) nasal blockage, (ii) nasal discharge, (iii) facial pain or pressure or (iv) reduction in sense of smell with at least one of the symptoms being nasal blockage or nasal discharge | Last 12 weeks | 
| Lung function | Spirometric lung function (Forced Expiratory Volume in one second (FEV1), and Forced Vital Capacity (FVC)) were measured pre- and post- administration of bronchodilator (salbutamol 200 mg). Spirometric restriction was defined by an FVC below the limit of normal, chronic obstruction by an FEV1/FVC below the limit of normal. All spirometries were checked centrally for quality. Only spirometry that met the ERS/ATS criteria was accepted | Day | 
| Atopy | Skin prick tests (SPTs) to grass pollen, grass mix, Dermatophagoides pteronyssinus, Dermatophagoides farinae, cockroach (Blatella), olive, Alternaria, dog, Artemisia, birch, cat and Parietaria were conducted. A SPT was regarded as positive where the allergen weal was >1 mm more than the diluent control. Atopy was defined as any positive response to any of the allergens tested | 1 day | 
| Allergic rhinitis | Defined based on a positive answer to the question 'Do you have any nasal allergies or hay fever'? | Last month | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Asthma, Adults, Europe, Lung function, Allergy, Atopy, IgE, Sensitisation, Diet, Dietary patterns, Dietary antioxidants, Flavonoids, Fruits and vegetables, Food frequency questionnaire (FFQ), Fatty acids