A Longitudinal Study on the Effects of Cigarette Smoking on Rate of Decline in Spirometric Measurements in Male Japanese Workers

Abstract

To estimate the effect of cigarette smoking on decline of forced expiratory volume in one second (FEW) and forced vital capacity (FVC) with aging in the Japanese population, 461 male workers were longitudinally followed for over seven years. Analyses were conducted on 336 of them who were 30 years old or more, had not changed their smoking habits, were effectively followed up for at least three years, and had acceptable spirometric results in three or more surveys. The annual decline in the indices for each subject was estimated in the form of the slope of a simple regression after correction for height. Significant acceleration of the decline in FEV1 was observed as a result of cigarette smoking, and the magnitude of the effect appeared to be well within the range reported previously for white populations in Europe and North America. The magnitude of the decline in FEW of non-smokers, however, appeared smaller than in previous reports. These findings suggest that the susceptibility of Japanese people to cigarette smoke is similar to that of white populations in terms of acceleration of FEV1 decline, although there may be a racial difference in the magnitude of the decline in the ordinal aging process in Japanese and white populations. J Epidemiol, 1995; 5 : 59-65.