Smoking

Tobacco smoke (including passive exposure) is the most common risk factor associated with COPD. Continuous smokers have at least a 25% risk of developing COPD after twenty-five years of smoking and this risk increases with age as cumulative smoke exposure increases.¹

Smoking cessation is the primary measure for slowing the development of COPD at all stages of the disease. This is as relevant for patients with no current symptoms as it is for those at more severe stages of the disease. Those patients who continue to smoke will lose lung function at a rapid rate whereas those who stop smoking will deteriorate more slowly (although lost function cannot be regained).

The Fletcher-Peto curve illustrating the effect of continued smoking and smoking cessation on FEV₁ is illustrated in Figure 1.²

Figure 1: Fletcher-Peto curve illustrating the effect of smoking on FEV₁.²
Reproduced from BMJ, [Fletcher C, Peto R. The natural history of COPD. BMJ, 1977:1;1645-1648] with permission from BMJ Publishing Group Ltd.
 

References

1. Jorgensen NR, Schwarz P, Holme I, et al. The prevalence of osteoporosis in patients with COPD: a cross sectional study. Respir Med 2007;101:177-185.
2. Fletcher C & Peto R. The natural history of COPD. BMJ, 1977;1:1645-1648.