Smoking cessation: a preventive effect on the development of confirmed COPD

Quitting smoking can prevent the development of chronic obstructive pulmonary disease (COPD), confirm two studies presented at the 25 Congress of the European Respiratory Society (ERS) in Copenhague.Ces results are important in terms of public health because they can provide a quantitative assessment of the benefits of smoking cessation, commented one of the moderators of this oral session.

Tobacco is the main risk factor for COPD but until now no study had evaluated the preventive effect of smoking cessation, said Desiree Jansen of the University of Groningen (Netherlands).

With his colleagues, the Dutch researcher conducted a cohort study of 12,517 people after the general population, not with COPD at baseline. In the 25 years of monitoring, 1,206 people have developed the disease (9.6%).

These results allowed the authors to calculate the risk of COPD in a person who has never smoked shows 49% lower risk which faced the participants who smoked during the entire follow-up period.

Individuals who have stopped smoking at the time of enrollment also had a lower than smokers (53%) risk of COPD.

In contrast, the risk of COPD in former smokers who resumed smoking during the study joined the risk affecting those who still smoked.

The researchers then analyzed only data on one hand the people who continued to smoke throughout the study and secondly those who stopped. Overall, it appears that stopping smoking reduces by 45% the risk of developing COPD.

Positive point is the benefit of smoking cessation remains the same, even if the person also has one or more other risk factors for COPD (male, bronchial hyperresponsiveness, age over 50 years, cumulative amount smoked more than 35 pack-years, presence of airway hyperresponsiveness).

This work highlights the need to strengthen support programs for smoking cessation, Desiree Jansen added, noting that this study was only observational and, overall, only 5% of smokers successfully quit permanently without special support.

The second study presented during this session, with the aim to assess the progress and the absolute risk of COPD for over 25 years has indirectly led to the same conclusion as the first.

It was conducted by Anders Lokke of Hvidovre University Hospital (Denmark), on a comparable model. Using data from the Copenhagen City Heart Study, the Danish researchers analyzed the relationship between smoking cessation and COPD risk, analyzing the case of 2,096 people who did not have COPD at the time of inclusion in the study.

After 25 years of monitoring, it appears that, overall, 36% of people who have smoked have developed COPD against only 8% of those who had never smoked. Presenting the data from another perspective, the researcher also explained that after 25 years of follow 91.4% of never smokers are still healthy. This rate was 88.4% among former smokers and down to 62.8% in those who have smoked.

In addition, the results of this study also showed an association between smoking status and disease severity.

These results suggest that smoking cessation reduces the risk of COPD significantly, concluded Anders Lokke.