By Katherine Lee | Medically reviewed by Pat F. Bass III, MD, MPH for everydayhealth.com/
Studies have suggested a link between asthma and heart disease. Find out about the connection and whether you may be at risk.
Doctors have yet to hammer out a clear connection between asthma and heart disease, but the link is a statistical fact, according to Russell B. Leftwich, MD, a physician specializing in allergy and immunology in Nashville, Tenn., and a spokesperson for the American Academy of Allergy Asthma and Immunology. “Even when you take away smoking and other risk factors, there is still an increased risk of heart disease in people with asthma.”
Are you doing everything you can to manage your asthma? Find out with our interactive checkup.
Doctors have a variety of theories about the possible link between asthma and heart disease, including:
- The gene theory. One theory suggests some kind of genetic link. “There are 29 genes known to be associated with asthma,” says Leftwich. “Perhaps it’s one of those genes.”
- The inflammation question. Heart disease is an inflammatory disease, as that’s what makes the arteries harden. Similarly, asthma is caused by airway swelling. Leftwich notes it’s possible for inflammation in one part of the body to spread.
- The weight factor. Obesity certainly contributes to developing asthma and to developing heart disease, says Leftwich, but experts still don’t understand exactly what the connection is.
- A case of mistaken identity. “People who are having heart failure,angina, or heart pain such as tightness in the chest may mistake those symptoms for breathing difficulty and other asthma symptoms,” says Leftwich. Heart failure can cause fluid to build up in the lungs and airways, and can lead to symptoms that resemble asthma symptoms such aswheezing, coughing, and shortness of breath.
Is Asthma Medication a Culprit?
A big question mark about the link between asthma and heart disease concerns certain asthma medications.
“The medicines used to treat asthma may increase the likelihood of heart events,” says Leftwich. “For example, beta-agonists, which are quick-release drugs, stimulate the heart. It has long been thought that they may increase the chance of a cardiac event.”
Beta-agonists are all adrenalin derivatives and are known to affect the heart, explains Leftwich, adding, “They also lower the potassium level in the blood, which can lead to disturbances in heart rhythm.”
Similarly, high doses of corticosteroids, which are also commonly used to treat asthma, have been associated with atrial fibrillation, a condition in which the upper chambers of the heart quiver instead of beating normally.
It’s a chicken-or-egg conundrum: Doctors aren’t sure if the medications are causing the cardiovascular events or whether the asthma attacks are precipitating the heart disease. “Beta-agonists have long been suspected as a cause, but this has not been absolutely confirmed and there are some studies that suggest this is not the link,” says Leftwich.
For example, one recent study found that most people who used beta-agonists did not have a risk of heart disease and only patients with underlying heart disease had an increased risk, which was unrelated to the direct effects of the drugs.
That said, excessive use of beta-agonists over a short period of minutes or hours can have a dangerous effect on the heart, says Leftwich. But he adds that, again, it’s not clear whether overuse of beta-agonists is the cause of the link between asthma and heart disease. What do doctors know? “Severe asthma, and even severe attacks in persons who usually have only mild asthma, does lead to decreased oxygen in the blood and this certainly can have an effect on the heart,” Leftwich says.
Asthma and Heart Disease: Other Findings
One recent large-scale study of more than 15,000 men and women found a correlation between adult onset of asthma and heart disease in women. Researchers compared the risk of coronary heart disease or stroke in people with childhood-onset asthma to those with adult-onset asthma and found that women with adult-onset asthma have twice the risk for coronary heart disease and stroke, even after adjusting data for known heart disease risk factors such as age, body mass index, cigarette use, and a lack of exercise.
As an example of how asthma triggers may be part of the equation, another study found that ordinary exposure to even small amounts of coarse particles in the air, such as road or construction dust, raised bad cholesterol levels and increased coronary risk factors for heart problems in people with asthma. Considering the connection between these two conditions, talk to your doctor about managing asthma symptoms along with ways to maintain or even boost your cardiovascular health.
Learn more in the Everyday Health Asthma Center.