New research suggests that patients with allergic rhinitis face significantly lower risks for heart attacks, cerebrovascular disease, and all-cause mortality.
Several studies have suggested an association between allergy-related phenomena, such as eosinophilia, positive skin tests, total IgE, daily pollen burden and asthma, and cardiovascular disease. Now, new research suggests that patients with allergic rhinitis may be at lower risk for heart attacks and other cardiovascular events.
During a session on research highlights in asthma, rhinitis, and rhinosinusitis at the 2014 Annual Meeting of the American Academy of Allergy, Asthma & Immunology, held February 28 — March 4, 2014, in San Diego, CA, Angelina M. Crans Yoon, MD, described work she has carried out with her colleagues at Kaiser Permanente Los Angeles Medical Center on the relationship between both allergic rhinitis and asthma and cardiovascular disease. Crans Yoon gave a figure of 7% for the prevalence of allergic rhinitis in adults in the US.
Using the Kaiser Permanente Southern California regional database and ICD-9 codes, researchers matched a cohort of 109,229 allergic rhinitis patients and a cohort of 92,775 asthma patients 1:1 by age, sex, and ethnicity to reference cohorts. They compared the incidence of cardiovascular and cerebrovascular events and all-cause mortality from 1/1/1995 through 12/31/2012. They calculated hazard ratios (HR) using survival analysis with a fully-adjusted COX proportional model.
Crans Yoon and colleagues found that patients with allergic rhinitis had a significantly lower risk for acute myocardial infarction (HR 0.75), cerebrovascular disease (HR 0.81), and all-cause mortality (HR 0.51) than the control subjects. However, these patients’ risk for all cardiovascular events was equivalent to that for the control cohort (HR 0.97) for all cardiovascular events.
Asthma patients had a significantly higher risk of all cardiovascular disease (HR 1.36). However, the researchers found no corresponding increased risk of cerebrovascular disease (HR 1.03) or all-cause mortality (HR 1.00) although some previous research has suggested such links.
This group concluded that their study supported other results that patients with asthma have increased cardiovascular events. Their observations that patients with allergic rhinitis have decreased acute myocardial infarct, cerebrovascular disease, and all-cause mortality appear to be new findings. These suggest that atopy may not be contributing to the increased cardiovascular events seen in patients with asthma.
Crans Yoon also mentioned that the group’s findings were consistent with results obtained with the mouse model, whereas the correlation between data from other human studies and mouse data has been inconsistent. There have also been conflicting findings regarding IgE, with specific IgE levels being possibly inversely related to the incidence of allergic rhinitis.
Crans Yoon and colleagues plan to perform a secondary analysis on the data to try and find an explanation for the decreased risk of cardiovascular events in allergic rhinitis. The group will investigate whether the use of medication is a factor and they are starting to look at specific IgE in such patients. However, there are a limited number of patients for which specific IgE values have been obtained. The results of this study also complicate the role of genetics in the development of allergic diseases.
In a news release, Crans Yoon said, “In contrast, the group of patients with allergic rhinitis had significantly lower risks for heart attacks, cerebrovascular disease and all-cause mortality. The overall risk of all forms of heart disease in the allergic rhinitis patients was equal to the control group though. “More research is needed but considering the lower risk of heart attacks found in the allergic rhinitis patients, it suggests that the genetic tendency to develop allergic diseases may not be contributing to the increased risk of heart disease observed in the asthma patients.”