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

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

Interventions

DEVICE

Active Air Purifier

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.

DEVICE

Placebo Air Purifier

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.

Sponsors & Collaborators

• National Institute of Environmental Health Sciences (NIEHS)

  collaborator NIH

• Johns Hopkins University

  lead OTHER

Principal Investigators

• Meredith C. McCormack, MD, MHS · Johns Hopkins University, Pulmonary and Critical Care Medicine

Study Design

Allocation

RANDOMIZED

Purpose

OTHER

Masking

QUADRUPLE

Model

PARALLEL

Eligibility

Min Age

8 Years

Max Age

17 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2016-08-31

Primary Completion

2026-09-30

Completion

2027-09-30

Countries

• United States

Study Locations