Self-reported Asthma is Associated with Increased Risk of Hospitalization and/or Death Due to Coronary Heart Disease among Never Smoking Men and Women.
Inflammation is thought to play a crucial role in the pathogenesis of coronary atherosclerosis. Asthma is a chronic inflammatory disease and a major cause of pulmonary morbidity and mortality. However, very few prospective studies exist evaluating the question of whether asthma is related to increased risk of cardiovascular diseases, and none were restricted to never smokers. We examined the prospective association between self-reported asthma diagnosis and risk of hospitalization and/or death due to coronary heart disease (CHD, ICD-9 codes 410-414) in a large population-based sample. Data on self-reported health conditions, including asthma, and cardiovascular risk factors were collected at a health maintenance organization (HMO) in the San Francisco Bay Area between 1979 and 1985. The sample included 14,047 never smoking women and 7,989 never smoking men aged 35-89 years (mean ± SD, 50.4 ± 11.9 years), 56% Caucasian, who were free of known CHD at baseline. Of those, 652 women (4.6%) and 410 men (5.1%) self-reported physician-diagnosed asthma. Follow-up for hospitalization and/or death was available through the end of 1998 (median=13.4 years). Using Cox proportional hazards regression, we censored persons leaving the health plan at their last known date of HMO membership. Compared to subjects with no-known history of asthma, and after adjustment for age, sex, race, education level, alcohol consumption, body mass index, serum cholesterol, systolic blood pressure and diabetes, self-reported asthma was significantly associated with higher risk of hospitalization and /or death due to CHD (RR=1.33; 95% CI=1.05-1.67; p=0.02). Also in multivariate analysis, asthma under treatment at the time of the baseline examination was more strongly associated with CHD risk (RR=1.82; 95% CI=1.23-2.69; p=0.003). No interactions were found between self-reported asthma or asthma under treatment and patient sex. We conclude that, in a large representative population-based sample of non-smokers, self-reported asthma was associated with increased risk of coronary heart disease.