Clinical Significance of Symptoms in Smokers with Preserved Pulmonary Function.

TitleClinical Significance of Symptoms in Smokers with Preserved Pulmonary Function.
Publication TypePublication
Year2016
AuthorsWoodruff PG, R Barr G, Bleecker E, Christenson SA, Couper D, Curtis JL, Gouskova NA, Hansel NN, Hoffman EA, Kanner RE, Kleerup E, Lazarus SC, Martinez FJ, Paine R, Rennard S, Tashkin DP, Han MK
Corporate AuthorsSPIROMICS Research Group
JournalN Engl J Med
Volume374
Issue19
Pagination1811-21
Date Published2016 May 12
ISSN1533-4406
KeywordsAdult, Aged, Aged, 80 and over, asthma, Bronchodilator Agents, Confounding Factors, Epidemiologic, Female, Forced Expiratory Volume, Humans, Lung, Male, Middle Aged, Pulmonary Disease, Chronic Obstructive, smoking, Symptom Assessment, Tomography, X-Ray Computed, Vital Capacity
Abstract

BACKGROUND: Currently, the diagnosis of chronic obstructive pulmonary disease (COPD) requires a ratio of forced expiratory volume in 1 second (FEV1) to forced vital capacity (FVC) of less than 0.70 as assessed by spirometry after bronchodilator use. However, many smokers who do not meet this definition have respiratory symptoms.METHODS: We conducted an observational study involving 2736 current or former smokers and controls who had never smoked and measured their respiratory symptoms using the COPD Assessment Test (CAT; scores range from 0 to 40, with higher scores indicating greater severity of symptoms). We examined whether current or former smokers who had preserved pulmonary function as assessed by spirometry (FEV1:FVC ≥0.70 and an FVC above the lower limit of the normal range after bronchodilator use) and had symptoms (CAT score, ≥10) had a higher risk of respiratory exacerbations than current or former smokers with preserved pulmonary function who were asymptomatic (CAT score, <10) and whether those with symptoms had different findings from the asymptomatic group with respect to the 6-minute walk distance, lung function, or high-resolution computed tomographic (HRCT) scan of the chest.RESULTS: Respiratory symptoms were present in 50% of current or former smokers with preserved pulmonary function. The mean (±SD) rate of respiratory exacerbations among symptomatic current or former smokers was significantly higher than the rates among asymptomatic current or former smokers and among controls who never smoked (0.27±0.67 vs. 0.08±0.31 and 0.03±0.21 events, respectively, per year; P<0.001 for both comparisons). Symptomatic current or former smokers, regardless of history of asthma, also had greater limitation of activity, slightly lower FEV1, FVC, and inspiratory capacity, and greater airway-wall thickening without emphysema according to HRCT than did asymptomatic current or former smokers. Among symptomatic current or former smokers, 42% used bronchodilators and 23% used inhaled glucocorticoids.CONCLUSIONS: Although they do not meet the current criteria for COPD, symptomatic current or former smokers with preserved pulmonary function have exacerbations, activity limitation, and evidence of airway disease. They currently use a range of respiratory medications without any evidence base. (Funded by the National Heart, Lung, and Blood Institute and the Foundation for the National Institutes of Health; SPIROMICS ClinicalTrials.gov number, NCT01969344.).

DOI10.1056/NEJMoa1505971
Alternate JournalN Engl J Med
PubMed ID27168432
PubMed Central IDPMC4968204
Grant ListHHSN268200900019C / HL / NHLBI NIH HHS / United States
HHSN268200900009C / WH / WHI NIH HHS / United States
S10 OD018526 / OD / NIH HHS / United States
P30 ES005605 / ES / NIEHS NIH HHS / United States
K12 HL119997 / HL / NHLBI NIH HHS / United States
HHSN268200900015C / HL / NHLBI NIH HHS / United States
I01 CX000911 / CX / CSRD VA / United States
HHSN268200900018C / HL / NHLBI NIH HHS / United States
HHSN268200900014C / HL / NHLBI NIH HHS / United States
R01 HL095372 / HL / NHLBI NIH HHS / United States
HHSN268200900016C / HL / NHLBI NIH HHS / United States
R01 HL110906 / HL / NHLBI NIH HHS / United States
HHSN268200900017C / HL / NHLBI NIH HHS / United States
HHSN268200900020C / HL / NHLBI NIH HHS / United States
HHSN268200900013C / HL / NHLBI NIH HHS / United States
HHSN2682009000019C / / PHS HHS / United States
MS#: 
MS032
Manuscript Full Title: 
Clinical Significance of Symptoms in Smokers with Preserved Pulmonary Function.
Manuscript Lead/Corresponding Author Affiliation: 
Clinical Center: San Francisco (University of California at San Francisco)
ECI: 
Manuscript Status: 
Published and Public