From GOLD 0 to Pre-COPD

Currently the diagnosis of chronic obstructive pulmonary disease (COPD) requires the demonstration of airflow limitation, defined as a post-bronchodilator FEV1/FVC <0.7, a measurement that remains methodologically robust and widely available. FEV1 is one of the most powerful predictors of clinically relevant outcomes including symptoms, exacerbations and mortality. However, reliable data suggest that respiratory symptoms, in particular chronic bronchitis, airway abnormality and emphysema detected using modern imaging techniques such as computed tomography (CT), and certain physiologic measures including rapid decline in FEV1 and DLCO are present among individuals who do not meet spirometric criteria for COPD. These abnormalities may help to identify individuals at increased risk for developing airflow limitation in the future. Here, we review the evidence that support the use of the term "pre-COPD" in individuals with symptoms (e.g., "Non-Obstructive Chronic Bronchitis" (NOCB)), physiologic (e.g., low DLCO) and/or imaging abnormalities (e.g. CT emphysema) but spirometry in the normal range, who are at risk of developing COPD defined by a reduced FEV1/FVC ratio. We acknowledge, however, that further research on early disease in young individuals will be critical to develop a clinically operable definition of "pre-COPD" that demonstrates good sensitivity and specificity.