Why sniffles and sneezes should make you think about heart health this allergy season

Most people probably would not connect seasonal allergies with their hearts. Itchy, watery eyes and stuffy noses, sure – but not cardiovascular issues.

Researchers are finding signs of just such a link between allergies, asthma and heart health. And while nobody is saying your next sneeze is cause for alarm, experts say the connection is worth being aware of.

That link is not a straightforward case of an allergen triggering a sudden heart problem, said Dr. Rauno Joks, a rheumatologist and allergist at State University of New York Downstate Health Sciences University in Brooklyn. It's about long-term inflammation.

"You could say that allergic disease is a systemic and inflammatory condition," said Joks, who is both chief of the division and program director of allergy and immunology at the university. The stimulus may be pollen in the nose, but the response goes all the way down into the bone marrow, where the body creates specialized cells to fight off intruders.

That response can lead to chronic inflammation, he said. And as noted in a 2018 review of research on allergic inflammation in the American Heart Association journal Circulation, inflammation plays a role in both the initiation and progression of coronary artery disease, the buildup of plaque in the heart's arteries that can lead to a heart attack or stroke.

Joks was senior author of the largest study to examine the links between allergies and heart disease. Published in June in the Journal of Allergy and Clinical Immunology: In Practice, the study used data from about 603,000 people taking part in the U.S. National Health Interview Surveys between 1999 and 2018.

Dr. Sairaman Nagarajan, a physician editor at The Merck Manuals and an adjunct faculty member at SUNY Downstate Health Sciences, was lead author on that study. It found that both asthma and allergic rhinitis, the formal name for hay fever, were associated with increased odds for heart disease, heart attack, chest pain or any other self-reported heart condition.

Specifically, people who reported having allergic rhinitis in the prior year had 25% greater odds of also having coronary heart disease and 20% greater odds of having had a heart attack. The odds were even higher for people who'd recently had an asthma attack, which can be triggered by allergens.

Earlier studies had been less clear about or even contradicted the idea of connections between allergies and heart issues. Nagarajan said that those efforts were smaller and not as representative of the whole population but that long-term, forward-looking studies were needed to provide better answers.

The links between allergy-related inflammation and heart disease have been getting more attention of late, Nagarajan said. Such inflammation has long been seen as separate from the type related to arterial plaque. "So historically, they were viewed as different entities and different pathways, and they were treated differently. We're finding, especially with asthma, there's a lot more overlap than was previously thought."

Dr. Nora Lin, a Philadelphia-area allergist, has seen firsthand how allergies directly and indirectly affect cardiovascular health. Directly, when allergens inflame the respiratory tract, it can become hard to breathe. "If your breathing gets challenged or taxed because of chronic inflammation, that's going to affect your heart," she said.

Indirectly, restricted breathing can get in the way of heart-healthy exercise, she said. Patients regularly tell her, "'I can't do 30 minutes of exercise because I can't breathe five minutes into it.' And so they don't exercise, and that leads them down the sedentary path."

But Lin has also seen how an allergist and cardiologist can work together to make a difference. "I can point to one patient I have in particular who is the perfect example of this," she said.

The man, around 60 years old, had high blood pressure that he kept under control through medication. But his allergies and asthma would flare in the spring and fall as he worked in his garden, and his blood pressure also would creep up.

Instead of boosting his blood pressure medications, his cardiologist recommended he try allergy shots, which can help build resistance to allergens. It's not an approach that would work for everyone, Lin said, but "we were able to get him through five years of allergy shots, and he is a different person. His asthma is so much better controlled. His allergies are so much better controlled." And his blood pressure is no longer increasing at the end of allergy season.

Not every case will be so clear-cut, Lin said. But she and the other doctors have this advice about handling allergies with heart health in mind.

Start with the basics

Get screened and be vigilant about the standard risk factors for heart health, Joks said. Be aware of your blood pressure and cholesterol levels, monitor for diabetes and know your family history.

A symptom such as shortness of breath could be a sign of either asthma or heart disease, he said. A primary care physician can do a proper evaluation and send someone to specialized care if needed.

On the allergy side, Nagarajan said, if you had hay fever or severe and uncontrolled asthma within the past year, be aware of the risk to your heart. There is no guideline mandating a referral to a cardiologist, he said, but the concern would be greater in older people, given that risks from heart disease increase with age.

Get the right diagnosis

Even if you have classic allergy symptoms, don't assume you know the cause, Lin said. In her experience, "on any given day, over half the time, it turns out that it's not allergies."

Many people she sees taking over-the-counter medications for a cough, runny nose or post-nasal drip end up not having allergies but a form of reflux. Other people come in thinking they have allergies but end up having asthma, she said.

Getting the right treatment can make a world of difference. If people are easily fatigued or short of breath during activities, they assume it's because they're out of shape, Lin said. "People are surprised to learn that they really had allergies and asthma all along. And once you treat that, then you can finally do the exercise that is so crucial for cardiac health."

Watch these medications

Lin asks her patients to bring in a complete list of medications they've been taking, including supplements. They can overlap in complicated ways.

Many people take over-the-counter pseudoephedrine to treat a stuffy nose. "It's a great decongestant, but it can exacerbate high blood pressure," she said. And some beta blockers, which are used to treat high blood pressure, can interfere with albuterol, which is commonly used in asthma inhalers.

Another asthma treatment, oral corticosteroids, can increase blood pressure and affect blood sugar and cholesterol levels, Joks said.

Don't ignore symptoms

If your allergies leave you feeling lightheaded or cause chest pain, alert your doctor immediately, Nagarajan said. It could be a sign of a heart problem. Sudden chest pain can be a sign of a heart attack, and for that or other heart attack or stroke symptoms, call 911.

Coordinate care

Lin said that not everybody who is treated for allergies or asthma gets to work with an allergist. And she does not often get to follow up with allergy or asthma patients' cardiologists to see how treatment affected conditions such as high blood pressure.

She wishes she had more opportunities for such coordination. Given how common both heart disease and allergies are, "there's got to be huge overlap," she said.

And Lin said, "when we can improve somebody's allergies and asthma, whether they realize it or not, I think there's improvements in their cardiovascular health."