AIRWEIGHS: Investigating Obesity as a Susceptibility Factor for Air Pollution in Childhood Asthma

NCT02763917 | Active Not Recruiting DMC

• 2 other identifiers: IRB00074171P50ES018176
• Study Type: interventional
• Target: 198
• Locations: 1 country
• Sites: 1

Brief Summary

Background: Asthma and obesity are public health crises that have concurrently risen over the past decades, affecting millions of children in the United States and disproportionately affecting low-income minority children in urban areas. The same children at highest risk for asthma and obesity also have greater exposure to indoor and outdoor pollution. Emerging evidence suggests that obesity may confer increased susceptibility to health effects of air pollution. Methods: Aiming to provide causal-level evidence of these observational findings, we propose a home intervention study to 1) test whether targeted reductions of indoor Particulate Matter (PM) concentrations improve the respiratory health of overweight inner-city children with asthma more than that of lean inner-city children with asthma and 2) investigate mediators of susceptibility to indoor PM among overweight versus lean children with asthma. We will accomplish these aims using a 1:1 randomized controlled trial of 200 children with persistent asthma (half normal weight, half overweight) living in Baltimore City. Participants will be randomized to receive either two active air purifiers containing high-efficiency particulate air (HEPA) filters or two sham air purifiers with their filters removed. Implications: If the aforementioned observational findings are confirmed, implications will be directly relevant to the over 170 million children around the world now estimated to be overweight or obese.

Conditions

Asthma

Outcome Measures

Primary Outcomes (1)

• Maximum Symptom Days

  We have chosen symptoms based on the strong relationship between symptoms and PM observed in previous studies. Symptoms during the previous two weeks will be captured with standardized questions used in many inner-city asthma studies, including our own that detected a strong association between indoor PM and asthma symptoms. A 'maximum symptom days' variable will constructed as the maximum of the variables: days of slowed activity, days of wheezing, coughing or chest tightness when running or going upstairs, and nights of waking with asthma symptoms in the past two weeks. We will administer questionnaires to the primary caregiver of children 8-11 years and to both participant and caregiver for adolescents age 12-17. Previous studies have indicated concordance between adolescent and the caregiver responses, and we will collect data to assess concordance within our study population. Individual symptom variables will serve as secondary outcomes.

  Baseline and about 12 weeks after the intervention

Secondary Outcomes (5)

• Asthma Control

  Baseline and about 12 weeks after the intervention

• Asthma Symptoms

  Baseline and about 12 weeks after the intervention

• Health Care Utilization

  Baseline and about 12 weeks after the intervention

• Lung Function

  Baseline and about 12 weeks after the intervention.

• FENO

  Baseline and about 12 weeks after the intervention

Study Arms (2)

Active Air Purifier

ACTIVE COMPARATOR

Two portable air purifiers containing HEPA filters will be placed in the bedroom and room where the participant reports spending the most time. We have chosen to deploy two air purifiers because we have observed a 50% reduction in indoor PM concentrations with two air purifiers. Participants will be instructed to run the air purifiers continually. Participants will receive educational materials about environmental factors that are important for asthma health and environmental modification strategies. Participants will also receive educational materials about health benefits of maintaining a normal weight.

Device: Active Air Purifier

Placebo Air Purifier

PLACEBO COMPARATOR

Homes in the control group will receive placebo air purifiers that have the internal air filters removed, but which will run normally. Participants will receive educational materials about environmental factors that are important for asthma health and environmental modification strategies, and educational materials about health benefits of maintaining a normal weight. At the end of the study, participants in the control group will receive active air purifiers. A control group is needed to ensure that reduced pollutant levels and health effects are not due to temporal trends and 'placebo effects' of being enrolled in an intervention trial. Participants will also be informed that being in the study does not prevent them from purchasing and using air cleaners during the study period.

Device: Placebo Air Purifier

Interventions

Active Air Purifier DEVICE

Two portable air purifiers containing HEPA filters will be placed in the bedroom and room where the participant reports spending the most time. Participants will be instructed to run the air purifiers continually. Participants will receive educational materials about environmental factors that are important for asthma health and environmental modification strategies, and educational materials about health benefits of maintaining a normal weight.

Active Air Purifier

Placebo Air Purifier DEVICE

Homes in the control group will receive placebo air purifiers that have the internal air filters removed, but which will run normally. Participants will receive educational materials about environmental factors that are important for asthma health and environmental modification strategies, and educational materials about health benefits of maintaining a normal weight. At the end of the study, participants in the control group will receive active air purifiers. A control group is needed to ensure that reduced pollutant levels and health effects are not due to temporal trends and 'placebo effects' of being enrolled in an intervention trial. Participants will be informed that being in the study does not prevent them from purchasing and using air cleaners during the study period.

Placebo Air Purifier

Eligibility Criteria

• Age: 8 Years - 17 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17)

You may qualify if:

• years of age
• Persistent asthma (NAEPP criteria)
• Exacerbation in previous 12 months
• Non-smoker
• Spends ≥4 nights/week at home
• No plans to move during the study

You may not qualify if:

• Significant pulmonary or cardiac disease
• Home not appropriate candidate due to disrepair
• Underweight, defined by BMI \<5th percentile
• Pregnancy

Sponsors & Collaborators

• Johns Hopkins University: lead
• National Institute of Environmental Health Sciences (NIEHS): collaborator

Study Sites (1)

Meredith McCormack

Baltimore, Maryland, 21224, United States

Location

Related Publications (1)

• Kaviany P, Brigham EP, Collaco JM, Rice JL, Woo H, Wood M, Koehl R, Wu TD, Eakin MN, Koehler K, Hansel NN, McCormack MC. Patterns and predictors of air purifier adherence in children with asthma living in low-income, urban households. J Asthma. 2022 May;59(5):946-955. doi: 10.1080/02770903.2021.1893745. Epub 2021 Mar 10.

  PMID: 33625291 DERIVED

MeSH Terms

Conditions

Asthma

Condition Hierarchy (Ancestors)

Bronchial Diseases; Respiratory Tract Diseases; Lung Diseases, Obstructive; Lung Diseases; Respiratory Hypersensitivity; Hypersensitivity, Immediate; Hypersensitivity; Immune System Diseases

Study Officials

• Meredith C. McCormack, MD, MHS

  Johns Hopkins University, Pulmonary and Critical Care Medicine

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: QUADRUPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: OTHER
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: May 3, 2016
• First Posted: May 5, 2016
• Study Start: August 1, 2016
• Primary Completion (Estimated): September 1, 2026
• Study Completion (Estimated): September 1, 2027
• Last Updated: October 3, 2025

Record last verified: 2025-09

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)