Exacerbations and lung function decline in COPD: new insights in current and ex-smokers

Respir Med. 2007 Jun;101(6):1305-12. doi: 10.1016/j.rmed.2006.10.012. Epub 2006 Nov 16.


Aim: To investigate whether there is a significant relationship between an increased frequency of exacerbations and the rate of forced expiratory volume in 1s (FEV(1)) decline in COPD patients. METHODS-MEASUREMENTS: About 102 COPD patients (44 smokers, 58 ex-smokers) participated in a 3-year prospective study. Exacerbations were identified as worsening of patient's respiratory symptoms as recorded on diary cards. Spirometry was performed every 6 months. The effect of frequent exacerbations on lung function was investigated using random effects models.

Results: The median (mean(95% CI)) annual exacerbation rate was 2.85 (3.1 (2.7-3.6)). Patients with an annual exacerbation rate over the median rate had significantly lower baseline post-bronchodilation FEV(1)(%pred), higher MRC dyspnoea score and chronic cough compared to patients who had an annual exacerbation rate less than the median. The average annual rate of FEV(1)(%pred), adjusted for smoking decline (DeltaFEV(1)), was found significantly increased in frequent compared to infrequent exacerbators (P=0.017). The highest DeltaFEV(1) was observed in smokers frequent exacerbators and a significant interaction between exacerbation frequency and DeltaFEV(1) was also observed in ex-smokers.

Conclusions: Our findings suggest that an increased frequency of exacerbations is significantly associated with FEV(1) decline even in ex-smokers. Thus, smoking and frequent exacerbations may have both negative impact on lung function. Smoking cessation and prevention of exacerbations should be a major target in COPD.

MeSH terms

  • Aged
  • Chronic Disease
  • Cough / etiology
  • Cough / physiopathology
  • Disease Progression
  • Dyspnea / etiology
  • Dyspnea / physiopathology
  • Female
  • Follow-Up Studies
  • Forced Expiratory Volume*
  • Humans
  • Male
  • Middle Aged
  • Prospective Studies
  • Pulmonary Disease, Chronic Obstructive / etiology
  • Pulmonary Disease, Chronic Obstructive / physiopathology*
  • Severity of Illness Index
  • Smoking / adverse effects
  • Smoking / physiopathology*
  • Smoking Cessation
  • Spirometry