Air Pollution Warning for Americans With Heart Problems

Individuals with pre-existing heart problems may be more at risk from the negative consequences of air pollution on heart health, a study by Intermountain Health, Salt Lake City, has found. Scientists compared inflammatory markers in the blood of 35 people without heart disease, and 44 people with heart disease, on days when air pollution was low versus very high. "These biomarkers rose in response to air pollution in people who already had heart disease, but not in patients who were heart disease free, showing that heart failure patients are not as able to adapt to changes in the environment," said principal investigator Professor Benjamin Horne, of Intermountain Health, in a statement. Heart disease is the leading cause of death among adults in the United States, according to the Centers for Disease Control and Prevention, linked to 1 in 5 deaths that occurred in 2022. The phrase "heart disease" is an umbrella term that refers to multiple diseases and events that occur related to the heart and blood system, including cardiovascular disease, coronary artery disease, stroke and heart attack. "It's important that individuals with known heart disease, including those diagnosed with heart failure, need to be especially cautious during periods of poor air quality," said Horne. "This includes exercising indoors, making sure to take their prescribed medications, and avoiding areas like roadways and highways where there's a lot more traffic and pollution." Previous research has shown that people with some chronic health conditions, including some forms of heart disease, struggle more during spikes in air pollution. But in this study, researchers at Intermountain Health found that two markers of inflammation were elevated in the blood of heart failure patients on days of worse air quality.

But these inflammatory markers—called C-C motif chemokine ligand 27 (CCL27) and interleukin 18 (IL-18)—were not raised on low air quality days, or among individuals without heart problems. Inflammation is an immune system response to infection, invasion or injury, that can be triggered on a more permanent basis. This version of low-level, chronic inflammation is a key risk factor for heart disease. In this study, Intermountain Health researchers worked with scientists at Stanford University and the Harvard School of Public Health and examined the blood of patients enrolled in the Intermountain INSPIRE registry. Blood samples were collected of healthy patients and patients with diagnosed heart failure and preserved ejection fraction: a condition where the heart does not relax properly between contractions and pressure inside the heart can rise. The scientists analyzed the blood samples, looking at the levels of 115 different proteins that are signs of increased inflammation of the body. Some of the blood was drawn on days with low air pollution, and some on days when air pollution spiked, for instance, due to wildfire smoke. Horne said the findings gave scientists and doctors "some information about mechanisms in people with heart failure who are having inflammation," and that they suggested these individuals were "not as capable in responding to acute inflammation as people who are healthy." This research was presented on Saturday at the American Heart Association's 2024 Scientific Sessions international conference, held in Chicago. Do you have a tip on a food story that Newsweek should be covering? Is there a nutrition concern that's worrying you? Let us know via science@newsweek.com. We can ask experts for advice, and your story could be featured in Newsweek.

Reference

Horne, B. D., Haddad, F., Anderson, J. L., Maecker, H. T., Bair, T. L., Johnson, M. M., Bride, D., Muhlestein, J. B., Kim, J. B., Knight, S., Nadeau, K. C., Knowlton, K. U. (2024). Association of PM2.5 Air Pollution with Inflammatory Biomarkers in Patients with Heart Failure, Intermountain Health.