Lung volume measurements in patients at risk for chronic obstructive pulmonary disease (COPD) could be used to assess risk stratification, especially in smokers with abnormal lung volumes, according to a study published in the Annals of the American Thoracic Society.

Researchers analyzed the clinical significance of lung volume measurements and associated ratios representing air trapping to the development of adverse respiratory outcomes and COPD. The Veterans Administration Informatics and Computing Infrastructure database was used to collect data from patients who were smokers, older than 40 years of age, and at risk for COPD. All included patients also had preserved spirometry. Lung volume measurements correlated with air trapping included residual volume, functional residual capacity, inspiratory capacity, and their ratios to total lung capacity.

In the 7479 patients included, 30.8% experienced air trapping with the residual volume to total lung capacity greater than the upper limit of normal. Patients with the higher residual volume to total lung capacity ratio were more likely to be diagnosed with COPD (odds ratio [OR], 1.47±0.08; P <.001) and had higher all-cause mortality (hazard ratio, 1.41±0.06; P <.001) compared with patients with a normal residual volume to total lung capacity ratio. A measurement of an abnormal residual volume to total lung capacity ratio predicted a higher risk for spirometric COPD (OR, 1.27±0.15; P =.044).

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Future studies need to explore the physiologic and biologic mechanisms of the association between air trapping and the increased risk for the development of COPD to help create new therapeutic approaches.

The researchers concluded that “[s]mokers with abnormal lung volumes representing air trapping are at higher risk to develop adverse respiratory outcomes and COPD.”

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Disclosures: This research was supported by the Flight Attendant Medical Research Institute.


Zeng S, Tham A, Bos B, Jin J, Arjomandi M. Back to the box: using lung volumes to predict susceptibility to develop chronic obstructive pulmonary disease among smokers.Ann Am Thorac Soc. 2018;15(Suppl 4):S286-S287.