CT-quantified emphysema in male heavy smokers: association with lung function decline

Thorax. 2011 Sep;66(9):782-7. doi: 10.1136/thx.2010.145995. Epub 2011 Apr 7.

Abstract

Background: Emphysema and small airway disease both contribute to chronic obstructive pulmonary disease (COPD), a disease characterised by accelerated decline in lung function. The association between the extent of emphysema in male current and former smokers and lung function decline was investigated.

Methods: Current and former heavy smokers participating in a lung cancer screening trial were recruited to the study and all underwent CT. Spirometry was performed at baseline and at 3-year follow-up. The 15th percentile (Perc15) was used to assess the severity of emphysema.

Results: 2085 men of mean age 59.8 years participated in the study. Mean (SD) baseline Perc15 was -934.9 (19.5) HU. A lower Perc15 value correlated with a lower forced expiratory volume in 1 s (FEV(1)) at baseline (r=0.12, p<0.001). Linear mixed model analysis showed that a lower Perc15 was significantly related to a greater decline in FEV(1) after follow-up (p<0.001). Participants without baseline airway obstruction who developed it after follow-up had significantly lower mean (SD) Perc15 values at baseline than those who did not develop obstruction (-934.2 (17.1) HU vs -930.2 (19.7) HU, p<0.001).

Conclusion: Greater baseline severity of CT-detected emphysema is related to lower baseline lung function and greater rates of lung function decline, even in those without airway obstruction. CT-detected emphysema aids in identifying non-obstructed male smokers who will develop airflow obstruction.

Publication types

  • Comparative Study
  • Multicenter Study
  • Randomized Controlled Trial

MeSH terms

  • Disease Progression
  • Follow-Up Studies
  • Forced Expiratory Volume / physiology*
  • Humans
  • Male
  • Middle Aged
  • Pulmonary Emphysema / complications
  • Pulmonary Emphysema / diagnostic imaging*
  • Pulmonary Emphysema / physiopathology
  • Reproducibility of Results
  • Respiratory Insufficiency / diagnostic imaging*
  • Respiratory Insufficiency / etiology
  • Respiratory Insufficiency / physiopathology
  • Smoking / adverse effects*
  • Spirometry
  • Time Factors
  • Tomography, X-Ray Computed*