Is having asthma associated with an increased risk of dying from cardiovascular disease? A prospective cohort study of 446 346 Taiwanese adults

Objectives A significant proportion of cardiovascular disease (CVD) cannot be explained by well-known risk factors such as high cholesterol, hypertension and diabetes. One potential novel risk factor for CVD is asthma. We aimed to investigate the association between asthma and mortality due to CVD. Design Prospective cohort study. Setting A large health check-up programme from 1994 to 2011 in Taipei, Taiwan. Participants 446 346 Taiwanese adults. Each participant answered questions regarding asthma history (yes/no) and current daily use of asthma medications (yes/no). Active asthma was defined as those using current daily medications for asthma. Outcomes The participants were followed for mortality from CVD, coronary heart disease (CHD) and stroke obtained through linkage to the cause-of-death register until 31 December 2011. Results We found an increased risk of dying from CVD in individuals with active asthma (adjusted HR (aHR) 1.32, 95% CI 1.08 to 1.62). The risk of death from CHD or stroke was increased in a similar manner (aHR 1.16, 95% CI 0.78 to 1.73 and aHR 1.23, 95% CI 0.86 to 1.74, respectively) although the HR estimates were less precise than that of CVD. For deaths from CVD, CHD and stroke, we found stronger associations with active asthma than non-active asthma, and for CVD and stroke stronger associations in men than women. Conclusion Our study suggests that asthma, particularly active asthma, may be associated with adverse cardiovascular consequences.