Persistent asthma is linked to higher levels of inflammation and plaque in the arteries that deliver blood to the brain, potentially increasing heart attack and stroke risk. The corresponding study was published in the Journal of the American Heart Association.
"Many physicians and patients don't realize 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 lead study author Matthew C. Tattersall, D.O., M.S., assistant professor in the department of medicine at the University of Wisconsin in Madison. "The presence and burden of carotid artery plaque- [plaques in the arteries that deliver blood to the brain]- is a strong predictor of future cardiovascular events."
For the study, the researchers examined data from the ongoing Multi-Ethnic Study of Atherosclerosis (MESA) that began in 2000. Altogether, they included 5, 029 adults with an average age of 61 years old from six locations across the US. The participants were ethnically diverse: 26% identified as African American, 23% Hispanic, and 12% Chinese.
All participants reported their asthma status to physicians at the beginning of the study. 109 participants had persistent asthma- defined as requiring asthma medication daily to control symptoms- and 388 had intermittent asthma- defined as a history of the condition without the need for daily medication. The remaining participants did not have asthma.
Participants also received an ultrasound of the left and right carotid arteries at the start of the study, and underwent blood tests to measure inflammatory biomarkers.
After analyzing the data, the researchers found that 67% of those with persistent asthma and 49.5% of those with intermittent asthma had carotid plaques. Those with persistent asthma had an average of two plaques, whereas the intermittent group had one plaque. Meanwhile, 50.5% of the group without asthma had carotid plaques; those with plaques had an average of around one.
After adjusting for factors including sex, race, comorbidities, prescription use, and smoking, the researchers found that those with persistent asthma were almost twice as likely to have plaques in their carotid arteries than those without the condition. They also had higher levels of inflammatory biomarkers.
"This analysis tells us that the increased risk for carotid plaques among people with persistent asthma is probably affected by multiple factors," Dr. Tattersall said, "Participants who have persistent asthma had elevated levels of inflammation in their blood, even though their asthma was treated with medication, which highlights the inflammatory features of asthma. We know that higher levels of inflammation lead to negative effects on the cardiovascular system."
The researchers noted that their study was observational, so the identified associations may not be causal. Nevertheless, they concluded that their findings highlight the need for additional studies to investigate the shared mechanistic underpinnings of asthma and atherosclerotic cardiovascular disease risk.
Sources: Science Daily, Journal of the American Heart Association