New York: Home air purifiers can also improve cardiovascular health in people with chronic obstructive pulmonary disease, or COPD, a new research from Johns Hopkins University led by an Indian-origin scientist has revealed.
Cardiovascular diseases such as arrhythmias, heart failure, stroke and heart attack commonly accompany COPD, and both COPD and cardiovascular disease are leading causes of death around the world, according to the World Health Organisation.
The new six-month study, led by Johns Hopkins Medicine researchers and published in the American Journal of Respiratory and Critical Care Medicine, is a secondary study of a larger Johns Hopkins-led project, the CLEAN AIR study.
The CLEAN AIR study, which investigated the effects of indoor air pollution on COPD, found that people with COPD experienced improved symptoms after using portable air purifiers indoors.
"We've seen that air pollution in the home, where people spend a majority of their time, contributes to impairments in respiratory health. We hypothesised that this pollution is a big driver of cardiovascular disease and cardiac events in people with COPD," says lead author Sarath Raju, an assistant professor of medicine who specialises in obstructive lung diseases.
For the new study, researchers recruited 85 men and women from the original CLEAN AIR study, who were adults (average age 65) with COPD.
The level of PM 2.5 indoors should stay at or below 12 micrograms per cubic foot for the air to be considered healthy to breathe. Participants' homes had an average of 13.8 micrograms per cubic foot of PM 2.5.
Then, 46 randomised participants received two portable air cleaners with HEPA and carbon filters to use at home; the other participants received placebo air cleaners that circulated air but had the filters removed.
Researchers tracked and measured several indicators of lung and heart health at the one week, three-month and six-month periods of the study using standard clinical tests, such as blood pressure and heart ultrasounds (echocardiograms).
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 improved markers of heart health, specifically a 25 per cent increase in heart rate variability. Participants without the active filters saw no increase.