Background: Several diseases characterized by chronic inflammation and immune activation have been linked to enhanced risk for atherosclerosis. The potential association between allergies and atherosclerosis, however, remains to be defined.
Methods: The association between common allergic diseases (allergic rhinitis and asthma) and 5-year development and progression of carotid atherosclerosis (Bruneck Study) and high intima-media thickness in carotid and femoral arteries (Atherosclerosis Risk Factors in Male Youngsters [ARMY] study) was investigated. The Bruneck Study is a prospective population-based survey of 826 men and women aged 40 to 70 years; the ARMY study is a cross-sectional evaluation of 141 men aged 17 or 18 years.
Results: Subjects with allergic disorders were at a significantly increased risk for high intima-media thickness in the ARMY study (odds ratio, 2.5; 95% confidence interval, 1.1-5.5; P=.03) and for atherosclerosis development and progression in the Bruneck Study (odds ratio, 3.8; 95% confidence interval, 1.4-10.2; P=.007). The associations remained significant after multivariate adjustment for a broad array of established and potential vascular risk factors. When IgE levels were substituted for the clinical allergy variable, findings were confirmed in the Bruneck Study (adjusted odds ratio, 1.7; 95% confidence interval, 1.1-8.0), for a 1-SD increase in IgE level (P=.02).
Conclusions: This study documents enhanced atherosclerosis among subjects with common allergic diseases. Our findings fit well with the emerging concept that key components of allergies, such as leukotrienes or mast cells, are active in human atherogenesis and further extend the growing list of immune system-mediated and chronic inflammatory disorders that have been linked with enhanced risk for atherosclerosis.