Lung function decline in bronchiectasis

<bold>Introduction:</bold> Bronchiectasis patients experience an accelerated decline in forced expiratory volume in 1 second (FEV1). However, the pathophysiology of bronchiectasis is complex and the evolution over time of other functional variables is still unknown. Aim of the present study was to assess the trend over time in static and dynamic lung volumes in patients with clinically significant non-cystic fibrosis bronchiectasis <bold>Methods:</bold> This was a prospective, observational study of adult outpatients attending the Bronchiectasis Program of the IRCCS Fondazione Ca’ Granda Ospedale Maggiore Policlinico in Milan and of IRCCS S. Gerardo Hospital in Monza (Italy). Consecutive patients with clinically significant bronchiectasis diagnosed on high-resolution computed tomography scan in stable state were recruited and followed up between 2012 and 2018. Patients that underwent body plethysmography in at least two visits three years apart were considered for analysis. <bold>Results:</bold> A total of 255 patients were analyzed, with a mean follow up of 3.5 years (76.1% woman, median age (IQR) 67 (53-76) years). During follow up, patients experienced a median (IQR) decline in forced vital capacity of -30 (−320 - 0.220) ml and a decline in forced expiratory volume in the first second (FEV1) of 100 (−300 – 70). Total lung capacity declined by 40 (−420 – 430) ml and residual volume increased by 10 (−422 – 470) ml. <bold>Conclusions:</bold> There is a large variability in lung function decline in patients with bronchiectasis. Some patients experience a reduction in static volumes, indicating an evolution towards a restrictive pattern, in other cases we observed an increase in residual volume and air trapping. The clinical correlates of these lung function trajectories should be explored.