Influence of respiratory and cardiovascular diseases on smoking cessation

Aims: Varenicline is used in smoking cessation. The patients recruited by the respiratory physician at our unit had a higher rate of comorbidities than in other studies conducted in a general population of healthy smokers. This can be explained because they were referred from other respiratory specialists or from general practitioners to the Stop-Smoking Clinic. The aims of the study were: -evaluate if Varenicline effectiveness is influenced by any of these comorbidities -compare the use of different doses in all subgroups Methods: Open-label randomized parallel-group controlled trial with 1-year follow-up, at the Stop-Smoking Clinic of the Virgen Macarena University Hospital in Seville. Patients were randomized either to 1 mg or 0.5 mg (both doses were taken twice daily during 8 weeks). Results: Patients with metabolic syndrome (n=27) had better quit rates than those without this condition (74,1% vs 42,3%, p=0,01). Patients with chronic obstructive pulmonary disease (COPD) (n=162) were more successful in quitting smoking than those who did not have this disease (52,5% vs 43,5%, p=0,067). However, having bronchial asthma (n=41) was related to having more difficulties in stopping smoking (26,8% vs 49,1%, p=0,005). The differences obtained comparing doses were not remarkable, as they only were seen in very small subgroups. Conclusions: Some comorbidities are related to the success of the smoking cessation programme and it would be necessary to design specific studies for these subgroups of patients.