Effects of cigarette smoking status on lung function in Chinese people 40 years of age or over

Objective To observe the effect of smoking status on lung function in Chinese people >40 years of age by a 2-year longitudinal follow-up. Methods This study prospectively investigated 2 682 cases of pulmonary ventilation function, smoking status, regularity of residents drug combination and gender, age, height, weight and other information, observation time for two years, 2 290 people (85.4%) complete the follow-up study. Results Of the 2 290 people, 1 197 people (52.3%) are never-smokers, 467 people (20.4%) are ex-smokers, 626 people (27.3%) are current smokers.There were statistically significant differences in the number of age, sex, BMI, lung function COPD and combination therapy among the three groups.After 2 years of follow-up, results show that the lung function FEV1, FEV1 % pred, FVC, FEV1 / FVC showed decreased year by year.After adjusted the difference variables, It showed that, to compared with never smokers, ex-smokers significantly reduced lung function FEV1, FEV1 %pred and FEV1 / FVC, P values were 0.030, 0.011 and <0.001, current smokers significantly reduced lung function FEV1/FVC. Conclusions Never-smokers have the slowest decline in lung function, We advocate non smoking or smoking as early as possible. Key words: Smoking; Lung function; Chronic obstructive pulmonary disease