@article {Osanaip1008, author = {Shinobu Osanai and Mie Aoki and Toshiyuki Ogasa}, title = {Influences of smoking on FEV1 remain over the long-term after cessation}, volume = {38}, number = {Suppl 55}, elocation-id = {p1008}, year = {2011}, publisher = {European Respiratory Society}, abstract = {Backgrounds and objectives: Natural course of forced expiratory volume in on second (FEV1) after smoking cessation is still unclear. We sought to assess influences of smoking habits to FEV1 in subjects without obstructive pulmonary disorders.Subjects and methods: Subjects were recruited from patients who attended to rural primary care clinics except for respiratory disorders. Each participant was asked to answer a questionnaire including smoking history and measure forced vital capacity (FVC) and FEV1. Results are presented as mean {\textpm} SD.Results: In the present study, 408 of male (61.2{\textpm}13.7 years-old) and 500 of female (60.2{\textpm}15.6 years-old) were analyzed. There was no significant difference in smoking duration between current smokers (28.1{\textpm}23.9 pack/year) and ex-smokers (31.3{\textpm}30.8 pack/year). In the ex-smokers, duration after smoking cessation was 14.3{\textpm}13.0 yr. Both \%FEV1 (measured FEV1/predicted FEV1 (\%)) in current smokers (95.3{\textpm}14.8, n=253) and \%FEV1 in ex-smokers (93.7{\textpm}15.4, n=269) were lower than \%FEV1 in non-smokers (103.2{\textpm}16.5, n=386) (P\<0.01). There was no difference in\%FEV1 among the subgroups divided by age both in current smokers and ex-smokers. Also, there was no difference in \%FEV1 among the subgroups divided by duration of smoking cessation in ex-smokers. The ex-smokers under 40 years-old had lower \%FEV1 comparing to non-smokers under 40 years-old. The ex-smokers who stopped smoking more 20 years had still lower \%FEV1 than that in non-smokers.Conclusion: In conclusion, influence of smoking on FEV1 starts under 40 year-old, and decrease of FEV1 remain over 20 years after cessation in subjects without obstructive pulmonary disorders.}, issn = {0903-1936}, URL = {https://erj.ersjournals.com/content/38/Suppl_55/p1008}, eprint = {https://erj.ersjournals.com/content}, journal = {European Respiratory Journal} }