Relationship between habit of cigarette smoking and airflow limitation in healthy Japanese individuals: the Takahata study.
BACKGROUND
Chronic obstructive pulmonary disease (COPD) is characterized by chronic airflow limitation. The prevalence of airflow limitation in Japan is 10.9% (16.4% of males and 5.0% of females). Cigarette smoking is well known as a major cause of COPD. However, few epidemiological studies have evaluated the effects of cigarette smoking on pulmonary function in healthy subjects.


METHODS
Subjects aged 40 years or older (n=2,917), who had participated in a community-based annual health check in Takahata, Japan, from 2004 through 2005, were enrolled in the study. The smoking histories of these subjects were investigated using a self-reported questionnaire. Forced vital capacity (FVC), forced expiratory volume in 1 second (FEV(1)), and forced expiratory flow at 25-75% of FVC (FEF(25-75)) were measured by standard procedures using spirometric machines.


RESULTS
There were 554 current smokers (18.6%) and 403 former smokers (13.8%). The prevalence of airflow limitation defined by FEV(1)/FVC <0.7 in this population was 10.6%, and prevalence of airflow limitation defined by 5th percentile lower limit of normal was 6.4%. In smokers, percent predicted values of measured spirometric parameters (%FVC, %FEV(1) and %FEF(25-75)) decreased significantly with age, except for male %FVC. Also, percent predicted values of measured spirometric parameters decreased significantly with increasing pack-years, except for female %FEF(25-75).


CONCLUSIONS
Cigarette smoking increased the prevalence and severity of airflow limitation. It is concluded that cigarette smoking increases the risk of airflow limitation in a healthy Japanese population.
Osaka
Daisuke
D
Department of Cardiology, Pulmonology, and Nephrology, Yamagata University School of Medicine.
Shibata
Yoko
Y
Abe
Shuichi
S
Inoue
Sumito
S
Tokairin
Yoshikane
Y
Igarashi
Akira
A
Yamauchi
Keiko
K
Kimura
Tomomi
T
Sato
Michiko
M
Kishi
Hiroyuki
H
Takabatake
Noriaki
N
Sata
Makoto
M
Watanabe
Tetsu
T
Konta
Tsuneo
T
Kawata
Sumio
S
Kato
Takeo
T
Kubota
Isao
I
D000368:Aged; D044466:Asian People / Q000208:ethnology*; D003153:Community Health Services / Q000379:methods; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology; D006801:Humans; D007564:Japan / Q000208:ethnology; D008297:Male; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000208:ethnology / Q000209:etiology / Q000503:physiopathology*; D012123:Pulmonary Ventilation / Q000502:physiology*; D015656:Respiratory Mechanics / Q000502:physiology; D012907:Smoking / Q000009:adverse effects / Q000208:ethnology / Q000503:physiopathology*; D014797:Vital Capacity / Q000502:physiology