Are patients with asthma at increased risk of coronary heart disease?

Background Inflammation plays a role in the pathogenesis of athero-thrombosis. Because of the chronic, inflammatory nature of asthma, we hypothesized a possible link asthma and prospective risk of coronary heart disease (CHD). Methods We performed a cohort study among 70 047 men and 81 573 women, 18-85 years old, enrolled in a large managed care organization in Northern California. Asthma was ascertained by self-report at baseline in 1964-1973 and/or interim hospitalization for asthma during follow-up. The primary endpoint was combined non-fatal or fatal CHD. Results After a median follow-up time of 27 years, and adjusting for age, race/ethnicity, education level, smoking status, alcohol consumption, body mass index, serum total cholesterol, white blood cell count, hypertension, diabetes, and history of occupational exposures, asthma was associated with a 1.22-fold (95% CI: 1.14, 1.31) increased hazard of CHD among women. This association was seen both in never and in ever smoking women, and in younger and older women. By contrast, asthma was not associated with CHD among men (multivariate-adjusted hazard ratio = 0.99; 95% CI: 0.93, 1.05). Conclusions Asthma was independently associated with a modest but statistically significant increased hazard of CHD among women. Further studies are warranted to confirm or refute these preliminary epidemiological findings.