Zeng S, et al. - In this study of the Veterans Affairs electronic health records, researchers investigated the significance of abnormal lung volumes that reflect air trapping in smokers with preserved spirometry (normal FEV₁ to FVC ratio). For identified 7479 patients, who were at risk for COPD (ever smokers >40 years of age without restrictive lung disease) and had preserved spirometry and concomitant lung volume measurements, they analyzed subsequent health records for clinical diagnoses of COPD, healthcare utilisation, follow-up spirometry and mortality. They found that air trapping was common in smokers with preserved spirometry. Moreover, findings highlighted the role of air trapping as a predictor of adverse respiratory outcomes and progression to overt COPD.