Adults with a history of allergies have an increased risk of coronary heart disease.
A new study used 2012 data from a cross-sectional survey of the U.S. population. The allergic group included adults with at least 1 allergic disorder, including but not limited to asthma, respiratory allergies, digestive allergies, and skin allergies. The study included around 35,000 adults with an average age of 48.5 years and more than half of whom were women. The researchers found that individuals with a history of allergies between the ages of 18 and 57 had an increased risk of developing high blood pressure and coronary heart disease. “For patients with allergic disorders, routine evaluation of blood pressure and routine examination for coronary heart disease should be given by clinicians to ensure early treatments are given to those with hypertension or coronary heart disease,” elaborated Yang Guo, PhD, and the study’s lead author.1
Previous studies have reported an association between allergies and cardiovascular disease, but these findings had remained controversial. Long-term follow-ups alongside large cohort studies will be needed to confirm the findings. However, knowing that allergies may be an underlying cause of high blood pressure and heart disease may help management of these disease in individuals in the future.
How do allergies contribute to high blood pressure?
There are a few theories on how allergies contribute to high blood pressure. When an allergen triggers an allergic response, histamines in the body boost blood flow into the area that the allergen attacks. This causes the immune system to send antibodies to that area, triggering inflammation. Inflammation is the body’s natural way of fighting off allergens and pathogens. Science shows that a long-lasting inflammatory response is an underlying factor in many chronic diseases including diabetes, high blood pressure, and heart disease.
Many allergy medications are antihistamines, which counter the body’s inflammatory response. Antihistamines and pseudoephedrine (also found in many allergy medications), constrict blood flow by narrowing the blood vessels in the body. These narrow blood vessels can also lead to high blood pressure and increased heart rate. Another medication often prescribed for allergies or asthma is steroids. Steroids increase both blood pressure and blood sugar. Having high blood pressure and high blood sugar are important risk factors for coronary artery disease and stroke.2
In addition, nasal congestion associated with many allergy disorders may interfere with breathing while sleeping. Nasal congestion may promote or worsen sleep apnea. People with sleep apnea have an increased risk of high blood pressure. About 50% of sleep apnea patients have hypertension. Sleep apnea can also contribute to poor quality of sleep and shorter periods of sleep, which can raise someone’s blood pressure.3
- Katie Glenn. “History of Allergies May Be Associated with Increased Risk of High Blood Pressure, Heart Disease”, available at History of Allergies May Be Associated with Increased Risk of High Blood Pressure, Heart Disease – American College of Cardiology (acc.org)
- Harvard Health Publishing. “Ask the doctor: Can allergies cause high blood pressure?”, available at Ask the doctor: Can allergies cause high blood pressure? – Harvard Health
- Alexa Fry. “How Sleep Apnea Affects Blood Pressure”, available at How Sleep Apnea Affects Blood Pressure | Sleep Foundation