Adults with persistent asthma may be more likely to have a heart attack or stroke due to excess plaque buildup in the carotid arteries, according to new research published today in the journal Journal of the American Heart AssociationIt is an open-access, peer-reviewed journal of the American Heart Association. People in the study had more plaque buildup in the carotid arteries, the large arteries on the left and right side of the neck that carry blood to the brain, than people without asthma.
Asthma is a respiratory condition that causes inflammation of the airways — often due to allergies — that makes breathing difficult. Chronic inflammation over time is known to contribute to the buildup of arterial plaques known as atherosclerosis and is associated with an increased risk of plaque rupture, leading to a heart attack or stroke.
“Many clinicians and patients are not aware that asthmatic airway inflammation may affect the arteries, so for people with persistent asthma, addressing risk factors for cardiovascular disease may be really helpful,” said study lead author Matthew C. Tattersall. Assistant Professor in the Department of Medicine at the University of Wisconsin at Madison. “The presence and burden of carotid artery plaque is a strong predictor of future cardiovascular events.”
For this analysis, the researchers used data from participants enrolled in the Multiethnic Study of Atherosclerosis (MESA) to examine a possible association between asthma and carotid plaque. MESA is a research study of nearly 7,000 adults that began in 2000 and still follows participants today in six locations across the United States: Baltimore; chicago; New York; Los Angeles County, California; Forsyth County, North Carolina; and St. Paul, Minnesota. At the time of enrollment, all MESA participants were free of cardiovascular disease.
The researchers reviewed the health data of 5,029 adults, average age 61, with baseline risk factors for cardiovascular disease and for whom carotid artery ultrasound data was available. The group of participants is diverse: 26% of adults identified themselves as African American, 23% identified themselves as Hispanic and 12% identified themselves as Chinese. In addition, more than half of the group (53%) were female.
Participants in this analysis group were classified as having persistent asthma, intermittent asthma, or no asthma. The persistent asthma subgroup, defined as using daily control medications to control asthma symptoms, consisted of 109 participants. The intermittent asthma subgroup, defined as a history of asthma, but no use of daily medications to control asthma symptoms, consisted of 388 participants; The rest of the participants did not have asthma.
At the start of the MESA study, all participants had ultrasounds of the left and right carotid arteries to determine any plaque in the carotid artery. The total plaque score determined the number of plaques in the walls of the carotid arteries. Blood levels of the inflammatory biomarkers interleukin-6 (IL-6) and C-reactive protein (CRP) were also measured at the start of the MESA study.
The analysis found:
- Carotid plaque was present in 67% of the participants with persistent asthma and 49.5% of the participants with intermittent asthma. Those with persistent asthma have an average of two carotid plaques, and those with intermittent asthma have about one carotid plaque.
- Carotid plaque was present in 50.5% of non-asthmatic participants, with an average of about one carotid artery plaque.
- After adjusting for age, sex, race, weight, other health conditions, use of prescription medications, and smoking, participants with persistent asthma had nearly two times higher odds of developing plaque in the carotid arteries than those without asthma.
When compared to non-asthmatic participants, those with persistent asthma had higher levels of inflammatory biomarkers. (Individuals with persistent asthma had an average IL-6 level of 1.89 pg/mL, while those without asthma had an average IL-6 level of 1.52 pg/mL.) -6 and CRP in the fully adjusted analysis did not reduce the association between persistent asthma and carotid artery plaque.
“This analysis tells us that the increased risk of carotid plaques among people with persistent asthma is likely influenced by multiple factors,” Tattersall said. “Participants with persistent asthma had elevated levels of inflammation in their blood, despite their asthma being treated with medication, which highlights the inflammatory features of asthma. We know that high levels of inflammation lead to negative effects on the cardiovascular system.”
In 2019, the American Heart Association issued guidelines for the primary prevention of cardiovascular disease including inflammatory disorders such as arthritis and lupus as cardiovascular risk factors. This study adds to the understanding of the impact of inflammatory diseases on cardiovascular health.
“The most important message from our findings is that more significant forms of asthma are associated with more cardiovascular disease and cardiovascular events,” Tattersall said. “Tackling cardiovascular risk factors through lifestyle and behavior modification can be a powerful preventative tool for patients with more severe forms of asthma.”
Everyone can improve cardiovascular health by following the American Heart Association’s 8 Life Basics: eat healthy food, get physical activity, don’t smoke, get enough sleep, maintain a healthy weight, and control your cholesterol, sugar, and blood pressure levels. Cardiovascular disease claims more lives each year in the United States than all forms of cancer and chronic lower respiratory disease combined, according to the American Heart Association.
The main limitation of the study is that it was observational because it was an analysis of the data, and thus, the findings suggest an association between asthma and an increased risk of cardiovascular disease, rather than cause and effect.
Co-authors are Alison S. Dasiewicz, MS; Robin L. McClelland, Ph.D.; Nizar Jarjour, MD; Claudia E. Korkarz, DVM; Carol C. Mitchell, Ph.D.; Stefan Esno, Ph.D.; Moyses Szklo, MD, MPH; and James H. Stein, MD, FAHA.
The study was supported by a Peer Development Award from the American Heart Association.