Clinical trial NCT02763917: AIRWEIGHS: Investigating Obesity as a Susceptibility Factor for Air Pollution in Childhood Asthma
Official title: AIRWEIGHS: Investigating Obesity as a Susceptibility Factor for Air Pollution in Childhood Asthma
Study type: INTERVENTIONAL
Overall status: ACTIVE_NOT_RECRUITING
Phase: NA
Conditions: Asthma
Lead sponsor: Johns Hopkins University
Sponsor class: OTHER
Collaborators: name: National Institute of Environmental Health Sciences (NIEHS)
First posted: 2016-05-05
Enrollment: 198
Sex: ALL
Minimum age (years): 8
Maximum age (years): 17
Standard ages: CHILD
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: OTHER

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.

Detailed description: The primary object of this study is to determine the efficacy of a targeted environmental intervention among overweight inner city children as compared to normal weight inner city children with asthma.

Specific Aim #1: To determine if overweight inner-city children, compared to lean inner-city children, have greater improvement in asthma with an air purifier intervention aimed at reducing indoor PM.

Hypothesis 1: An intervention using HEPA filter air purifiers in the homes of inner-city children with asthma will be associated with greater respiratory improvement in overweight children than in normal weight children.

Specific Aim #2a: To investigate mediators of susceptibility among overweight versus normal weight children with asthma.

Hypothesis #2. Candidate mediators, including increases in a) tidal volume and thereby increases in doses of inhaled particles, b) inflammatory and oxidative stress responses, c) corticosteroid resistance, and d) sleep disordered breathing mediate increased susceptibility to indoor PM among overweight versus normal weight children with asthma.

Children with asthma will be enrolled in the study for about 16 weeks. They will have three clinic visits, an overnight sleep study, and two home environmental assessments for one week each. They will have a home and clinical assessment before randomization and another home and clinical assessment about 12 weeks after randomization. The primary outcome measure is maximum number of asthma symptom days.

Eligibility criteria: Inclusion Criteria:

1. 8-17 years of age
2. Persistent asthma (NAEPP criteria)
3. Exacerbation in previous 12 months
4. Non-smoker
5. Spends ≥4 nights/week at home
6. No plans to move during the study

Exclusion Criteria:

1. Significant pulmonary or cardiac disease
2. Home not appropriate candidate due to disrepair
3. Underweight, defined by BMI \<5th percentile
4. Pregnancy

Primary outcomes:
measure: Maximum Symptom Days
timeFrame: Baseline and about 12 weeks after the intervention
Secondary outcomes:
measure: Asthma Control
timeFrame: Baseline and about 12 weeks after the intervention
measure: Asthma Symptoms
timeFrame: Baseline and about 12 weeks after the intervention
measure: Health Care Utilization
timeFrame: Baseline and about 12 weeks after the intervention
measure: Lung Function
timeFrame: Baseline and about 12 weeks after the intervention.
measure: FENO
timeFrame: Baseline and about 12 weeks after the intervention
Other outcomes:
Locations:
city: Baltimore
country: United States
facility: Meredith McCormack
state: Maryland
Study officials:
affiliation: Johns Hopkins University, Pulmonary and Critical Care Medicine
name: Meredith C. McCormack, MD, MHS
role: PRINCIPAL_INVESTIGATOR
References:
citation: 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.