Cardiorespiratory fitness may reduce long-term risk for bronchiectasis

Preservation of cardiorespiratory fitness over 2 decades was associated with lower odds for developing bronchiectasis on CT scans at 25 years, researchers reported in Radiology.

“Studies demonstrated that higher levels of cardiorespiratory fitness were associated with a reduced risk of declining lung function and incident airway diseases, such as chronic obstructive pulmonary disease,” Alejandro A. Diaz, MD, MPH, instructor in medicine at Harvard Medical School and associate scientist in the division of pulmonary and critical care medicine at Brigham and Women’s Hospital, and colleagues wrote. “Nevertheless, whether cardiorespiratory fitness reduces the risk of bronchiectasis is, to our knowledge, unknown.”

Researchers conducted a secondary analysis of the Coronary Artery Risk Development in Young Adults (CARDIA) cohort, a long-term, prospective, observational study of healthy individuals aged 18 to 30 years. The current analysis focused on 2,177 participants (mean age, 25 years; 56.2% women). Participants underwent treadmill exercise testing during visits in year 0 and 20. Cardiorespiratory fitness was assessed by the duration of treadmill exercise, and the 20-year difference was used as the fitness measurement.

The primary outcome was development of bronchiectasis on the chest CT scans performed at year 25.

At year 25, 209 (9.6%) participants had bronchiectasis.

In multivariable models, preservation of cardiorespiratory fitness during follow-up was associated with lower odds of bronchiectasis at time of chest CT scan at year 25 (OR = 0.88; 95% CI, 0.8-0.98; P = .02) after adjusting for various other confounders, including age, race, sex, study site, BMI, smoking status, tuberculosis history, pneumonia, asthma, myocardial infarction, peak lung function and cardiorespiratory fitness at baseline, according to the results. This model also showed an association with change in cardiorespiratory fitness over 20 years and bronchiectasis severity, with CT scores of 2 or less vs. no bronchiectasis (OR = 0.88; 95% CI, 0.79-0.98; P = .02) and CT scores greater than 2 vs. no bronchiectasis (OR = 0.83; 95% CI, 0.7-0.91; P = .02).

The researchers reported a consistent, strong association when cough and phlegm were included in bronchiectasis (OR = 0.72; 95% CI, 0.59-0.87; P < .001), according to the results.

“Our results suggest fitness might be a modifiable factor that can contribute positively to the preservation of airway health,” the researchers wrote.

In an accompanying editorial, Jadranka Stojanovska, MD, assistant professor in the department of radiology and director of the cardiothoracic MRI program at Michigan Medicine at the University of Michigan, Ann Arbor, said, “[t]he corollary of these results suggests that high cardiorespiratory fitness decreases systemic and airway inflammation, improves the capacity and efficiency of cardiorespiratory systems with improved airway perfusion including mucociliary system, and therefore prevents the development of bronchiectasis.

“The underlying premise is that improving cardiorespiratory fitness presents health professionals with unique opportunities to encourage lifestyle-based strategies designed to reduce the risk of respiratory diseases including bronchiectasis,” Stojanovska wrote.

Reference:

Stojanovska J. Radiology. 2021;doi:10.1148/radiol.2021210422.