Explore the intriguing links between asthma, allergies, and heart disease, hinting at shared inflammatory pathways and potential preventive strategies, urging further reading for insights into managing these conditions effectively.

The heart and lungs represent continuous organ systems that regulate gas exchange. In addition to their overlapping physiology, the pathophysiology between the organ systems also overlaps. For instance, asthma and atopic dermatitis contribute to heart failure, coronary artery disease, and other forms of cardiovascular disease (CVD).

Allergic disorders

In the study, the allergic group exhibited at least one of the following: asthma, respiratory allergy, digestive allergy, or skin allergy. The researchers found that individuals with a history of allergic disorders who were aged 18–57 years had a higher risk of high blood pressure. Asthma contributed most to the risk of hypertension and coronary heart disease.

In another population-based study (n=91,692), Danish researchers found that the highest risk of coronary heart disease was observed in patients with asthma-COPD overlap with late-onset asthma and FEV1 <50%.[2] They also found that asthma was correlated with coronary heart disease, but the hazard ratio (HR) was only 1.1 in those with asthma without allergy, compared with an HR of 1.4 in those with asthma and allergies.

Furthermore, patients with active asthma are more likely to experience (ischemic) stroke vs those with inactive disease.  

Results from the largest asthma and atopic dermatitis genome-wide association study (GWAS) showed a causal relationship between allergic disease and heart failure, with inflammation being a key factor.[4] The researchers noted the findings “emphasise the importance of asthma and allergy control in the prevention and management of heart failure.”

Mechanisms

Asthma can be linked to CVD by three possible mechanisms, according to the Hypertension Research authors.

Second, chronic airway obstruction due to prolonged asthma results in decreased pulmonary function and hypoxemia. Hypoxia may contribute to the pathogenesis of atherosclerosis, in part by the increased secretion of inflammatory mediators.

Third, medications used to treat asthma, including steroids, long-acting β2-agonists (LABAs), or long-acting antimuscarinic antagonists (LAMAs), may contribute to CVD.

Chronic atopic dermatitis also increases the risk of dying of CVD, according to authors publishing in The Journal of Atherosclerosis and Thrombosis, with inflammation once again being the tie that binds.[5]

“Speculated mechanisms linking chronic dermatitis with CVD include inflammation, which is in part related to impaired skin barrier, platelet dysfunction, and decreased fibrinolysis—all of which can contribute to increased clotting—and treatment for eczema,” wrote one author. “In fact, observational evidence suggests that severe eczema is more clearly associated with an increased risk of CVD, and long-term treatment for chronic eczema by itself appears to increase the risk.”

Clinical significance

The relationship between atopy and heart disease is still being investigated, and no evidence-based interventions can yet be recommended. Nevertheless, experts have floated potential preventive interventions based on recent studies.

First, it’s important to appropriately manage asthma—especially in patients with risk factors for CVD. These patients should have their risk factors for CVD systematically assessed and aggressively targeted—including smoking, hypertension, diabetes, and dyslipidemia.

Second, patients with allergic disorders should have their blood pressure routinely evaluated—along with a routine examination for coronary heart disease—to ensure early treatment.

Disclaimer: This story is contributed by Naveed Saleh and is a part of our Global Content Initiative, where we feature selected stories from our Global network which we believe would be most useful and informative to our doctor members.