Suspected bronchiectasis, defined as a combination of clinical symptoms and radiologic evidence of abnormal airways, is associated with a 15% higher risk for death in adults with normal spirometry, according to a new study suggesting that smokers with no apparent deficit in lung function may face significant health risks associated with bronchiectasis.
Researchers analyzed data from 7662 non-Hispanic Black and White current and former smokers aged 45-80 years who were part of the COPDGene study.
Participants were stratified into groups with normal spirometry (n = 3277), preserved ratio impaired spirometry (PRISm) (n = 986), and obstructive spirometry (n = 3399).
Among all participants, 17.6% had suspected bronchiectasis, which was identified by CT using measurements of an airway-to-artery ratio (AAR) greater than 1, plus two of the following symptoms: cough, phlegm, dyspnea, and a history of two or more exacerbations.
During a median follow-up of 11 years, 2095 (27.3%) of participants died.
Participants with suspected bronchiectasis had a 15% higher risk for 10-year mortality compared with those without airway thickening (difference in mortality probability, 0.15; 95% CI, 0.09 to 0.21).
Participants with obstructive spirometry (COPD) and suspected bronchiectasis experienced a greater risk for mortality (10-year cumulative all-cause mortality probability, 0.26; 95% CI, 0.24-0.28). The increased risk was observed across different stages of COPD severity, including mild to moderate and severe to very severe cases.
In a secondary analysis using CT measurement alone, the researchers found that all-cause mortality increased with increasing quartiles of AAR greater than 1 among the normal spirometry, PRISm, and COPD groups.
“These findings support including lung imaging as a tool for clinically defining bronchiectasis and for COPD workup to improve patient care,” the study authors wrote.
The study was published in Annals of Internal Medicine. The lead author is Alejandro A. Diaz, MD, MPH, of Harvard Medical School and Brigham and Women’s Hospital, Boston, Massachusetts.
Because the COPDGene cohort only included Black persons and White persons, the findings may not be generalizable to other racial groups. The imaging protocol used to define bronchiectasis is not routinely used in clinical settings. Further research is needed to establish causality.
The study was funded by the National Heart, Lung, and Blood Institute. The study authors report no conflicts of interest.
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