title: Smoking cessation in COPD causes a transient improvement in spirometry and decreases micronodules on high-resolution CT imaging.
abstract: BACKGROUND
  Smoking cessation is of major importance for all smokers; however, in patients with COPD, little information exists on how smoking cessation influences lung function and high-resolution CT (HRCT) scan appearances.
  
  
  METHODS
  In this single-center study, we performed screening spirometry in a group of heavy smokers aged 40 to 80 years (N = 358). We then studied the effects of smoking cessation in two groups of selected subjects: smokers with COPD (n = 38) and smokers with normal spirometry (n = 55). In parallel to subjects undergoing smoking cessation, we studied a control group of nonsmokers (n = 19).
  
  
  RESULTS
  Subjects with COPD who quit smoking had a marked, but transient improvement in FEV1 at 6 weeks (184 mL, n = 17, P &lt; .01) that was still present at 12 weeks (81 mL, n = 17, P &lt; .05) and only partially maintained at 1 year. In contrast, we saw improvement in the transfer factor of lung for carbon monoxide at 6 weeks in both subjects with COPD who quit smoking (0.47 mmol/min/kPa, n = 17, P &lt; .01) and subjects who quit smoking with normal spirometry (0.40 mmol/min/kPa, n = 35, P &lt; .01). An upper-zone single HRCT image slice reliably identified emphysema at baseline in 74% of smokers with COPD (28 of 38) and 29% of healthy smokers (16 of 55). Smoking cessation had no significant effect on the appearances of emphysema but decreased the presence of micronodules on HRCT imaging.
  
  
  CONCLUSIONS
  Cigarette smoking causes extensive lung function and HRCT image abnormalities, even in patients with normal spirometry. Smoking cessation has differential effects on lung function (FEV1 and gas transfer) and features on HRCT images (emphysema and micronodules). Cessation of smoking in patients with COPD causes a transient improvement in FEV1 and decreases the presence of micronodules, offering an opportunity for concomitant therapy during smoking cessation to augment these effects. Smoking cessation at the earliest possible opportunity is vital to minimize permanent damage to the lungs.
authors: Chest and Allergy Department, St. Mary's Hospital, Imperial College Healthcare NHS Trust, London.
authors: Jaideep
authors: J
authors: Dhariwal
authors: Departments of Thoracic Medicine, Radiology, and Lung Function and Clinical Studies Unit, National Heart and Lung Institute at the Royal Brompton Hospital, Imperial College, London.
authors: Rachel C
authors: RC
authors: Tennant
authors: Departments of Thoracic Medicine, Radiology, and Lung Function and Clinical Studies Unit, National Heart and Lung Institute at the Royal Brompton Hospital, Imperial College, London.
authors: David M
authors: DM
authors: Hansell
authors: Novartis Pharmaceuticals UK Ltd, Horsham, England.
authors: John
authors: J
authors: Westwick
authors: Novartis Pharmaceuticals UK Ltd, Horsham, England.
authors: Christoph
authors: C
authors: Walker
authors: Departments of Thoracic Medicine, Radiology, and Lung Function and Clinical Studies Unit, National Heart and Lung Institute at the Royal Brompton Hospital, Imperial College, London.
authors: Simon P
authors: SP
authors: Ward
authors: Departments of Thoracic Medicine, Radiology, and Lung Function and Clinical Studies Unit, National Heart and Lung Institute at the Royal Brompton Hospital, Imperial College, London.
authors: Neil
authors: N
authors: Pride
authors: Departments of Thoracic Medicine, Radiology, and Lung Function and Clinical Studies Unit, National Heart and Lung Institute at the Royal Brompton Hospital, Imperial College, London.
authors: Peter J
authors: PJ
authors: Barnes
authors: Chest and Allergy Department, St. Mary's Hospital, Imperial College Healthcare NHS Trust, London.
authors: Onn Min
authors: OM
authors: Kon
authors: Departments of Thoracic Medicine, Radiology, and Lung Function and Clinical Studies Unit, National Heart and Lung Institute at the Royal Brompton Hospital, Imperial College, London. Electronic address: t.hansel@imperial.ac.uk.
authors: Trevor T
authors: TT
authors: Hansel
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D005541:Forced Expiratory Volume; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000000981:diagnostic imaging* / Q000503:physiopathology; D011856:Radiographic Image Enhancement; D012907:Smoking / Q000009:adverse effects / Q000503:physiopathology; D016540:Smoking Cessation; D000074606:Smoking Prevention; D013147:Spirometry; D014057:Tomography, X-Ray Computed / Q000379:methods*