Healthy Eating Better Breathing: A Feeding Study in Patients With Asthma

Not Applicable

Completed

• Conditions: Asthma
• Interventions: Other: healthy diet

• Registration Number: NCT02904655
• Lead Sponsor: Johns Hopkins University

Brief Summary

The study is a randomized, crossover meal-replacement pilot intervention to determine feasibility of a larger scale dietary trial in asthma and gather preliminary evidence for the impact of a healthy diet on asthma outcomes. Participants with doctor-diagnosed asthma were randomized to crossover trial of a 4-week dietary intervention or usual diet with a 4-week washout period. During the dietary intervention, all meals and snacks were provided by the study.

Detailed Description

The objective of the study is to demonstrate feasibility of a randomized, controlled clinical trial of a dietary intervention in a population of adults with asthma and to determine sample size estimates for a larger, more definitive trial aimed at improving asthma clinical outcomes and improving markers of inflammation and oxidative stress. The study uses a feeding trial design comprised of a 4 week dietary intervention in which all meals are provided to study participants and a 4 week control diet comprised of usual dietary intake. Participants are randomized to the intervention or control diet and then cross over to the alternate assignment after a 4 week washout period.

Study Timeline

• Study Start: 2012-09
• Primary Completion: 2013-02
• Study Completion: 2013-02
• Status Verified: 2016-09
• Study First Submitted: 2016-09-09
• Study First Submitted QC: 2016-09-13
• Study First Posted: 2016-09-19
• Last Update Submitted: 2016-09-21
• Last Update Posted: 2016-09-23

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 19

Inclusion Criteria

• ages 18-50, self-reported physician diagnosis and treatment for asthma within the 12 months prior to enrollment, stable asthma defined as no asthma exacerbation (emergency department visit, systemic steroid treatment, or urgent care visit) or respiratory infection in the 4 weeks prior to enrollment.

Exclusion Criteria

• active smokers,pregnant or breastfeeding, using systemic corticosteroids or warfarin, had another major pulmonary diagnosis or significant systemic illness, reported excessive alcohol consumption (over 14 drinks per week or six or more drinks on one or more occasions per week), reported food allergy, or weighed over 350 pounds or changed weight by over ten pounds in the two months prior to screening

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
healthy diet	healthy diet	Participants were provided all meals and snacks for four weeks. Menus were created to target a healthy diet high in unsaturated fats.

Primary Outcome Measures

Name	Time	Method
Feasibility as assessed by the number of participant drop outs	Change from baseline and 4 weeks	Feasibility will be assessed by the number of drop outs.
Adherence assessed by serum carotenoids	Change from baseline to 4 weeks	Serum carotenoids will be measured at baseline and at 4 weeks. An increase in serum carotenoids is expected with adherence to the dietary intervention.
Adherence using 24 hour diet recall	Change from baseline to 4 weeks	Adherence to the dietary intervention will be assessed using self-report of dietary intake via 24 hour dietary recall.

Secondary Outcome Measures

Name	Time	Method
FEV1	Difference between baseline and 2 weeks	Spirometry will be measured according to the American Thoracic Society standards. The forced expiratory volume in one second (FEV1) will be assessed and compared between baseline and 2 weeks after the dietary intervention
FVC	Difference between baseline and 4 weeks	Spirometry will be measured according to the American Thoracic Society standards. The forced vital capacity (FVC) will be assessed and compared between baseline and 4 weeks after the dietary intervention
Asthma status	Difference between baseline and 2 weeks	Asthma Control Test (ACT, range 5-25, higher score denoting better asthma control). The change in score between baseline and week 2 will be assessed.
Asthma Quality of Life Questionnaire (AQLQ)	Difference between baseline and 2 weeks	Asthma Quality of Life Questionnaire (AQLQ) is a 32 item questionnaire and each question uses a 7-point Likert scale (7 = not impaired at all - 1 = severely impaired). Scores between week 0 (baseline) and week 2 will be assessed.
FEV1/FVC ratio	Difference between baseline and 2 weeks	Spirometry will be measured according to the American Thoracic Society standards. The forced expiratory volume in one second (FEV1)/forced vital capacity (FVC) ratio will be assessed and compared between baseline and 2 weeks after the dietary intervention
Exhaled nitric oxide	Difference between baseline and 2 weeks	Exhaled nitric oxide is an indicator of airway inflammation and will be measured according to American Thoracic Society standards at baseline and 2 weeks.
Adherence assessed by serum carotenoids	Difference between baseline and 2 weeks	Serum carotenoids will be measured at baseline and at 4 weeks. An increase in serum carotenoids is expected with adherence to the dietary intervention.
Asthma Symptom Utility Index	Difference between baseline and 2 weeks	Asthma Symptom Utility Index (ASUI, range 0-1, higher score denoting fewer symptoms) will be measured and the difference between week 2 and week 0 (baseline) will be assessed.