Risk of COPD with obstruction in active smokers with normal spirometry and reduced diffusion capacity.

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.

Harvey BG ，Strulovici-Barel Y ，Kaner RJ ，Sanders A ，Vincent TL ，Mezey JG ，Crystal RG ... -  《-》

Comparison of clinical features between non-smokers with COPD and smokers with COPD: a retrospective observational study.

Zhang J ，Lin XF ，Bai CX 《International Journal of Chronic Obstructive Pulmonary Disease》

Identification of COPD Patients at High Risk for Lung Cancer Mortality Using the COPD-LUCSS-DLCO.

The COPD-Lung Cancer Screening Score (COPD-LUCSS) is a tool designed to help identify patients with COPD with the highest risk of developing lung cancer (LC). The COPD-LUCSS includes the determination of radiological emphysema, a potential limitation for its implementation in clinical practice. The diffusing capacity for carbon monoxide (DLCO) is a surrogate marker of emphysema and correlates well with CT-determined emphysema. To explore the use of the COPD-LUCSS using the DLCO instead of radiological emphysema, as a tool to identify patients with COPD at higher risk of LC death. The Body Mass Index, Airflow Obstruction, Dyspnea, Exercise Performance international cohort database was analyzed. By logistic regression analysis, we confirmed that the other parameters included in the COPD-LUCSS (age > 60, pack-years > 60, BMI < 25) were independently associated with LC death. We selected the best cutoff value for DLCO that independently predicted LC death. We then integrated the new COPD-LUCSS-DLCO assigning points to each parameter according to its hazard ratio value in the Cox regression model. The score ranges from 0 to 8 points. By regression analysis, age > 60, BMI <25 kg/m(2), pack-year history > 60, and DLCO < 60% were independently associated with LC diagnosis. Two COPD-LUCSS-DLCO risk categories were identified: low risk (scores 0-3) and high risk (scores 3.5-8). In comparison to patients at low risk, risk of death from LC increased 2.4-fold (95% CI, 2.0-2.7) in the high-risk category. The COPD-LUCSS using DLCO instead of CT-determined emphysema is a useful tool to identify patients with COPD at risk of LC death and may help in its implementation in clinical practice.

de-Torres JP ，Marín JM ，Casanova C ，Pinto-Plata V ，Divo M ，Cote C ，Celli BR ，Zulueta JJ ... -  《-》

On the role of abnormal DL(CO) in ex-smokers without airflow limitation: symptoms, exercise capacity and hyperpolarised helium-3 MRI.

Kirby M ，Owrangi A ，Svenningsen S ，Wheatley A ，Coxson HO ，Paterson NA ，McCormack DG ，Parraga G ... -  《-》

The effect of comorbidities on COPD assessment: a pilot study.

Weinreich UM ，Thomsen LP ，Bielaska B ，Jensen VH ，Vuust M ，Rees SE ... -  《International Journal of Chronic Obstructive Pulmonary Disease》