Abstract

"Lung age" calculated from the height, sex, and 1-second forced expiratory volume is a new index to express the respiratory function. We assessed the differences in the lung age among smokers, past smokers, and non-smokers. The subjects comprised 886 Japanese who visited the Shimbashi Medical Checkup Office at Jikei University Hospital. The smokers (n=215), past smokers (n=300), and non-smokers (n=371) were classified. In the smokers, the number of cigarettes smoked per day was 19.7+/-9.8, and the period of smoking was 27.5+/-9.4 years. The non-smokers were divided into those in the presence or absence of second-hand smoke. The lung age added to the calendar age was 9.8+/-14.7 years in smokers, 4.8+/-17.8 years in past smokers, and -0.8+/-14.0 years in non-smokers. These data showed significant differences(p= 0.0003). The smoking index was calculated from smoking years multiplied by the cigarette number per day. The lung age with a smoking index >or=600 was 13.2+/-14.9 years, being significantly higher than that (7.2 +/-14.0 years) with a smoking index <600 (p=0.003). In the non-smokers, the lung age was -0.5+/-12.8 years in the presence and -1.0+/-14.1 in the absence of second-hand smoke. In conclusion, smoking increases the lung age.