Association of chronic respiratory symptoms with incident cardiovascular disease and all-cause mortality: findings from the Coronary Artery Risk Development in Young Adults Study

Abstract Background Respiratory and cardiovascular disease (CVD) frequently coexist; however, there is limited evidence on the relationship between chronic respiratory symptoms in young adulthood and late-onset CVD. Research Question Are chronic respiratory symptoms in young adulthood associated with CVD and all-cause mortality in later life? Study Design and Methods A total of 4,621 participants from CARDIA (Coronary Artery Risk Development in Young Adults) cohort study aged 18–30 were included. Chronic respiratory symptoms were identified through respiratory symptom questionnaires in two consecutive exams. Incident CVD and all-cause mortality were adjudicated over 30-year follow-up. Multivariable Cox proportional hazards models were used to explore association of chronic respiratory symptoms with incident CVD and all-cause mortality. Results During a median follow-up of 30.9 years, 284 CVD events (6.15%) and 378 deaths (8.18%) occurred. After multivariable adjustment for demographics, cardiovascular risk factors, smoking and lung function, the hazard ratios (95% CIs) for CVD events were 1.51 (1.18-1.93) for any respiratory symptom, 1.57 (1.18-2.09) for cough or phlegm, 1.31 (1.01-1.68) for wheeze, 1.73 (1.25-2.41) for shortness of breath, and 1.32 (1.01-1.71) for chest illnesses. Similar findings were also observed in all-cause mortality. Comparing 0 versus 3-4 respiratory symptoms, the hazard ratios (95% CIs) were 1.97 (1.34-2.91) for CVD and 1.75 (1.23-2.47) for all-cause mortality. Similar results were observed in various sensitivity analyses. Interpretation Chronic respiratory symptoms in young adulthood are associated with an increased risk of CVD and all-cause mortality in midlife independent of established cardiovascular risk factors, smoking and lung function. Identifying chronic respiratory symptoms in young adulthood may help provide prognostic information regarding future cardiovascular health.