PITTSBURGH, Sept. 16, 2020 - People with one of the most common heart disorders who are exposed to greater levels of pollution have a 1.2-fold higher risk of stroke than their peers who live with less pollution, according to a JAMA Network Open study published recently by researchers at the UPMC Heart and Vascular Institute and University of Pittsburgh School of Medicine.
The study is the largest of its kind to include neighborhood-specific pollution data--rather than simply hospitalization data--and further emphasizes the importance of air pollution alerts in advising the activities of people with certain heart conditions.
"We measured pollution exposure at people's doorsteps by using geocoding and then determined their annual exposure to particulate matter. This approach and the sample size make our study particularly powerful," said Jared W. Magnani, M.D., M.Sc., UPMC cardiologist and associate professor of medicine at Pitt. "We can use this information to guide our patients by advising them to limit exposure to pollution. For example, we can notify those with atrial fibrillation to avoid being outside on days with unhealthy air quality, which may reduce their risk of stroke."
Magnani and his colleagues followed more than 31,000 people living in Allegheny County since 2007 with atrial fibrillation (AFib), a common heart rhythm disorder affecting at least 2.7 million Americans. Using suitcase-sized air pollution monitors mounted on telephone poles, the team was able to measure the exact levels of fine particulate pollution--soot--that the participants were breathing on a daily basis. The Pittsburgh region is ranked by the American Lung Association as one of the 10 most polluted in the U.S.
The researchers found that stroke risk steadily increased with higher daily exposure to air pollution. People with AFib already are at five times the risk of stroke, so the additional risk posed by fine particulate pollution is particularly concerning, Magnani noted.
"Our results advance the understanding of how air pollution impacts public health and strengthens the argument for continued advocacy to curb pollution," he said. "Fine particulate pollution is very small--it is able to get into our bodies through our lungs and into our blood stream where it can trigger heart events."
The team went on to examine the impact of pollution on different demographic and socioeconomic groups. They found that fine particulate exposure is 1.5-fold higher in blacks compared to whites, and 1.3-fold higher in those living below poverty versus above.
"Pollution exposure correlates with socioeconomic position, as people living closer to industrial sources tend to be lower income and minoritized. Hence, air pollution worsens racial disparities in health outcomes, due to the increased residential exposure," Magnani said. "Our study indicates the importance of modifying pollution as a risk factor for adverse health outcomes."
Magnani said future research will explore how individual factors--such as physical activity, diet, health care access and medication--might interact with pollution levels to modify stroke risk for people with AFib.
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Additional authors on this research publication are Zachary J. Rhinehart, M.D., Ellen Kinnee, M.S., Emily Guhl, M.D., and Melissa Saul, M.S., all of Pitt; Utibe R. Essien M.D, M.P.H., of Pitt and the VA Pittsburgh Healthcare System; and Jane E. Clougherty, M.Sc., Sc.D., of Drexel University.
This research was funded by National Institutes of Health Award UL1 TR001857-02 and the University of Pittsburgh Clinical & Translational Science Institute.
To read this release online or share it, visit https://www.upmc.com/media/news/091620-af-pollution.
About the University of Pittsburgh School of Medicine
As one of the nation's leading academic centers for biomedical research, the University of Pittsburgh School of Medicine integrates advanced technology with basic science across a broad range of disciplines in a continuous quest to harness the power of new knowledge and improve the human condition. Driven mainly by the School of Medicine and its affiliates, Pitt has ranked among the top 10 recipients of funding from the National Institutes of Health since 1998. In rankings recently released by the National Science Foundation, Pitt ranked fifth among all American universities in total federal science and engineering research and development support.
Likewise, the School of Medicine is equally committed to advancing the quality and strength of its medical and graduate education programs, for which it is recognized as an innovative leader, and to training highly skilled, compassionate clinicians and creative scientists well-equipped to engage in world-class research. The School of Medicine is the academic partner of UPMC, which has collaborated with the University to raise the standard of medical excellence in Pittsburgh and to position health care as a driving force behind the region's economy. For more information about the School of Medicine, see http://www.medschool.pitt.edu.
Journal
JAMA Network Open