Asthma that requires daily medication is associated with a significantly higher risk of heart attack or stroke, according to a new study from the University of Wisconsin School of Medicine and Public Health (SMPH).
The study was presented Monday at the American Heart Association's Scientific Sessions in Dallas.
After adjusting for heart disease risk factors, including cholesterol, blood pressure, age, gender, and smoking, researchers found that people with asthma who required daily medications were 60 percent more likely to have a cardiovascular event such as a heart attack, stroke or other related conditions during a 10-year follow-up than people without asthma.
"Our study suggests that physicians should do all they can to control every other modifiable cardiovascular risk factor in patients with asthma," said Dr. Matthew C. Tattersall, assistant professor of medicine in the Division of Cardiology at the School of Medicine and Public Health and lead investigator of the study.
"Although we know that asthma and heart disease are both associated with increased levels of inflammation in the body, we do not yet know if the increased risk of heart disease is caused by the persistent asthma, the drugs used to treat persistent asthma, or if they simply share a common inflammatory cause."
In the study, asthmatics on controller medications, compared to non-asthmatics, had significantly higher levels of inflammatory markers including C-reactive protein and fibrinogen - the latter being a measure of blood stickiness that inflammation can worsen. Patients with a history of asthma but not currently requiring daily medication had intermediate levels of these markers.
The researchers say this study alone should not change clinical practice, but that it should serve as a reminder that primary preventive efforts are necessary for everyone and that additional research needs to be performed in order to further define the relationship between asthma and cardiovascular disease.
The study involved 6,792 participants from the Multi-Ethnic Study of Atherosclerosis (MESA), a prospective cohort study that examines risk factors and subclinical cardiovascular disease progression in an ethnically diverse population from six communities across the United States.
Patients were an average 62 years old, 47 percent male, 28 percent African-American, 22 percent Hispanic, 12 percent Chinese-American and 38 percent Caucasian. This research is the first contemporary prospective study to describe the association of asthma and cardiovascular disease events in a large, ethnically diverse cohort.
According to the most recent estimates by the Centers for Disease Control and Prevention, there are more than 25 million people nationwide diagnosed with asthma, 7 million of whom are children.
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