Abstract
COPD develops mainly due to accelerated decline in FEV1 from early adulthood throughout the middle-age (fast FEV1 decline trajectory). However, low maximal level of FEV1 in early adulthood may also be important (low maximally attained FEV1 trajectory). In this study we investigated different trajectories leading to the development of airflow limitation.
Design: Longitudinal study of individuals aged 20 to 40 yrs recruited from the general population in 1976-78 and followed with spirometry for 25 years (n = 1249) and with hospital admissions and mortality for 35 years (n= 2092).
Results: At the final spirometry, 203 (16.1%) had airflow limitation. They differed significantly from those without airflow limitation with regard to smoking, respiratory symptoms and frequency of acute respiratory infections but not with regard to blood levels of inflammatory biomarkers, early life events like childhood asthma and bronchitis or parental smoking. Among those with airflow limitation, 132 (65%) had an initial FEV1 >80% of predicted (mean 93%p), whereas 70 (35%) had initial FEV1 below 80% of predicted (mean 70%p). These two groups differed significantly with regard to mean annual FEV1 –decline (51 ml/yr (1.4%/yr) versus 29 ml/yr (1.1%/yr)), but not with regard to other factors except for a higher frequency of respiratory infections in the group with low initial FEV1. The incidence of hospital admissions due to respiratory diseases was higher in the group with low initial FEV1, but respiratory mortality in this group was lower than in those with high initial FEV1 and fast FEV1 –decline.
- © 2014 ERS