by A six-month study led by Johns Hopkins Medicine researchers concluded that the use of portable home air purifiers can improve some markers of cardiovascular health in people with chronic obstructive pulmonary disease or COPD. People suffering from COPD often experience shortness of breath, chest tightness, and a chronic cough. Cardiovascular diseases such as arrhythmias, heart failure, stroke, and heart attack often accompany COPD, and both COPD and cardiovascular disease are leading causes of death worldwide, according to the World Health Organization.
New research announced online Oct. American Journal of Respiratory and Critical Care Medicineis a secondary study of CLEAN AIR, a larger project led by Johns Hopkins. The CLEAN AIR study, which investigated the effects of indoor air pollution on COPD, found that people with COPD experienced improvement in their symptoms after using portable air purifiers indoors.
“We found that air pollution at home, where people spend most of their time, contributes to deterioration in respiratory health. We hypothesized that this pollution is a major driver of cardiovascular disease and cardiac events in people with COPD,” Lead says. author Sarath Raju, MD, MPH, is an assistant professor at the Johns Hopkins University School of Medicine specializing in obstructive pulmonary diseases.
Researchers recruited 85 men and women who were adults (mean age 65) with COPD in the original CLEAN AIR study. Participants primarily lived in the Baltimore area.
First, the researchers had trained technicians take indoor particulate matter air samples of various sizes from the participants’ homes. These indoor air pollutants consist of things like mold and pet dander. PM 2.5, one of the smallest types of particulate matter and smaller than the diameter of a human hair, can be harmful to respiratory and heart health by leaking into the bloodstream from the lungs and causing inflammation. The level of PM 2.5 inside must remain at or below 12 micrograms per cubic foot to be considered healthy for breathing air. Participants had an average of 13.8 micrograms/cubic foot PM 2.5 in their homes.
Then, 46 random participants were given two portable air cleaners with HEPA and carbon filters for home use; other participants received placebo air purifiers that circulated air but had their filters removed.
Using standard clinical tests such as blood pressure and heart ultrasounds (echocardiograms), the researchers tracked and measured various indicators of lung and heart health over the one-week, three-month, and six-month periods of the study. Additionally, participants wore heart rate monitors for 24 hours during each clinical testing period to assess heart rate variability.
At the end of the experiment, all 46 participants with active HEPA and carbon filters had a 25% increase in heart health markers, specifically heart rate variability. Participants without active filters did not see any increases.
Heart rate variability, or HRV, is a common measure of heart health calculated using other statistical variables, such as the standard deviation between heartbeats. HRV consists of changes in the time intervals between successive heartbeats. A healthy heart constantly adjusts its speed to meet the physical demands of the body, and therefore heart rate variability is higher.
Among the 20 participants who 100% used air purifiers with active filters at home, there was also a 105.7% increase in a measure of heart health variability called the root mean squared difference between consecutive normal heart rates, or RMSSD. associated with improved heart fitness.
The team also studied the effects of ultrafine particles in homes. These particles, which are smaller than one thousandth of a millimeter or one micron, can go deep into the lungs when inhaled and even pass into the bloodstream.
When the researchers evaluated 29 participants and their homes, they uncovered a correlation between the increase in ultrafine particles and poorer markers of heart health, such as lower heart rate variability. The team says more research is needed in this area.
“Ultrafine particles may be the most potent particles in terms of health outcomes,” says study author Meredith McCormack, MHS, MHS, professor of medicine at the Johns Hopkins University School of Medicine and director of the Center for Bridging Research (Lung Health). and Environment). “These particles and other indoor air pollutants can cause systemic inflammation in susceptible patients, such as patients with COPD. Our study shows that they also have a negative impact on cardiovascular health.”
“In the future, air purifiers may be something to be recommended to patients along with medications, but also be part of a larger debate about the importance of home environments,” says Raju.
Other researchers involved in the study include Han Woo, Ashraf Fawzy, Chen Liu, Nirupama Putcha, Aparna Balasubramanian, Cheng Ting Lin, Ronald Berger, and Nadia Hansel from Johns Hopkins University School of Medicine; Kirsten Koehler and Roger Peng of the Johns Hopkins Bloomberg School of Public Health; Chantel Lemoine of the University of Pittsburgh Medical Center; and Jennifer Wineke of the University of Maryland Medical Center.
This research was funded by NIH/NIEHS grants (R01ES022607, R21ES025840 and F32ES029786), an NHLBI grant (K12HL143957 and K23HL164151), and a Johns Hopkins University Catalyst Award.
