Mortality of asthma, COPD, and asthma-COPD overlap during an 18-year follow up

Background: We studied asthma, COPD, and asthma-COPD overlap (ACO) to predict mortality in a cohort of Finnish adults with an 18-year follow up.Methods: A national health examination survey representing Finnish adults aged >= 30 years was performed in 2000-2001. The study cohort included 5922 participants (73.8% of the sample) with all relevant data, including a comprehensive clinical examination and spirometry. These participants were followed continuously from baseline until end of 2018 for total, cardiovascular, cancer, and respiratory mortality through a record linkage. Asthma, COPD, and ACO were defined based on the survey data, including spirometry and register data. There were three separate groups of obstructive subjects (one definition excluding the others).Results: Asthma and COPD were significantly associated with higher total mortality in Cox's model adjusted for sex, age, smoking, education level, BMI, leisure time physical activity, cardiovascular disease, diabetes, and hypertension. Hazard ratios (HR) (95% confidence interval [CI]) for asthma, COPD, and ACO were 1.29 (1.05-1.58), 1.50 (1.20-1.88), and 1.26 (0.97-1.65), respectively. Additionally, asthma (HR 1.47, 95% CI 1.09-1.97) and COPD (HR 1.53, 95% CI 1.08-2.16) were associated with cardiovascular mortality. Although ACO did not predict mortality in the whole cohort, there was a significant association with mortality risk among those with hs-CRP 1-2.99 mg/l.Conclusions: Asthma or COPD predicts higher total mortality and premature death from cardiovascular diseases.