PT  - JOURNAL ARTICLE
AU  - Ben-Gary Harvey
AU  - Yael Strulovici-Barel
AU  - Robert J. Kaner
AU  - Abraham Sanders
AU  - Thomas L. Vincent
AU  - Jason G. Mezey
AU  - Ronald G. Crystal
TI  - Risk of COPD with obstruction in active smokers with normal spirometry and reduced diffusion capacity
AID  - 10.1183/13993003.02377-2014
DP  - 2015 Nov 05
TA  - European Respiratory Journal
PG  - ERJ-02377-2014
4099  - http://erj.ersjournals.com/content/early/2015/11/05/13993003.02377-2014.short
4100  - http://erj.ersjournals.com/content/early/2015/11/05/13993003.02377-2014.full
AB  - Smokers are assessed for chronic obstructive pulmonary disease (COPD) using spirometry, with COPD defined by the Global Initiative for Chronic Obstructive Lung Disease (GOLD) as airflow limitation that is not fully reversible with bronchodilators. There is a subset of smokers with normal spirometry (by GOLD criteria), who have a low diffusing capacity of the lung for carbon monoxide (DLCO), a parameter linked to emphysema and small airway disease. The natural history of these “normal spirometry/low DLCO” smokers is unknown.From a cohort of 1570 smokers in the New York City metropolitian area, all of whom had normal spirometry, two groups were randomly selected for lung function follow-up: smokers with normal spirometry/normal DLCO (n=59) and smokers with normal spirometry/low DLCO (n=46). All had normal history, physical examination, complete blood count, urinalysis, HIV status, α1-antitrypsin level, chest radiography, forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC), FEV1/FVC ratio and total lung capacity. Throughout the study, all continued to be active smokers.In the normal spirometry/normal DLCO group assessed over 45±20 months, 3% developed GOLD-defined COPD. In contrast, in the normal spirometry/low DLCO group, followed over 41±31 months, 22% developed GOLD-defined COPD.Despite appearing “normal” according to GOLD, smokers with normal spirometry but low DLCO are at significant risk of developing COPD with obstruction to airflow.Smokers with normal spirometry but low DLCO have a higher risk of COPD than smokers with normal spirometry and DLCO http://ow.ly/RWzxB