A new study conducted by researchers in Denmark has found that using high efficiency particle air (HEPA) filters might improve cardiovascular health.
The findings are based on a study, which showed that using HEPA filters for just two days significantly improved a key measure of cardiovascular health in healthy, non-smoking elderly individuals.
"Reduction of particle exposure by filtration of recirculated air for only 48 hours improved the microvascular function (MVF) in healthy elderly citizens. This suggests that indoor air filtration represents a feasible means of reducing cardiovascular risk," said Professor Steffen Loft, M.D., D.M.Sc., of the Institute of Public Health in Copenhagen.
The researchers said that abnormal function of the inner lining of small vessels is known to be a predictor of dangerous or possibly fatal cardiovascular events.
For the study, the researchers measured MVF and ambient airborne particles in the homes of 21 non-smoking couples aged 60-75 who lived close to heavily trafficked roads. An air filter was run with a HEPA filter for 48 hours and without a HEPA filter for another 48 hours.
The participants were monitored for their MVF and their blood and urine samples were analyzed to determine markers of inflammation, homeostasis and oxidative stress.
"Our main finding was a significant improvement in the function of small finger blood vessels after reduction of indoor air particles. This effect most likely indicates a general improvement in the function of the inner lining of small vessels, including those supplying the heart," Dr. Loft said.
The study showed that HEPA filtration removed about 60 percent of the ultrafine, fine and coarse air particles in homes, and was associated with an 8.1 percent improvement in individual MVF.
"We expected that removing air particles with the HEPA filters would result in improvement of MVF but we were heartened and surprised by the extent it did, considering the modest levels of particles in the indoor air of the homes of the elderly," Dr. Loft said.
None of the secondary endpoints considered showed significant differences after statistical corrections, suggesting that the mechanism underlying the improvement in MVF after air filtration remains unclear, and underscoring the need for further study.
"The results of this study indicate that reduction of particles in recirculated indoor air by filtration significantly improves MVF in a healthy, non-smoking, elderly population. The improvement could not be ascribed to significant reduction in inflammation or oxidative stress by means of biomarkers," Dr. Loft said.
The study was published in the second issue for February of the American Journal of Respiratory and Critical Care Medicine, published by the American Thoracic Society.