Cigarette nicotine yields and nicotine intake among Japanese male workers.

OBJECTIVES: To analyse brand nicotine yield including "ultra low" brands (that is, cigarettes yielding less-than-or-equal 0.1 mg of nicotine by Federal Trade Commission (FTC) methods) in relation to nicotine intake (urinary nicotine, cotinine and trans-3'-hydroxycotinine) among 246 Japanese male smokers. DESIGN: Cross sectional study. SETTING: Two companies in Osaka, Japan. SUBJECTS: 130 Japanese male workers selected randomly during their annual regular health check up and 116 Japanese male volunteers taking part in a smoking cessation programme. MAIN OUTCOME MEASUREMENTS: Subjects answered a questionnaire about smoking habits. Following the interview, each participant was asked to smoke his own cigarette and, after extinguishing it, to blow expired air into an apparatus for measuring carbon monoxide concentration. Urine was also collected for the assays of nicotine metabolites. RESULTS: We found wide variation in urinary nicotine metabolite concentrations at any given nicotine yield. Based on one way analysis of variance (ANOVA), the urinary nicotine metabolite concentrations of ultra low yield cigarette smokers were significantly lower compared to smokers of high (p = 0.002) and medium yield cigarettes (p = 0.017). On the other hand, the estimated nicotine intake per ultra low yield cigarette smoked (0.59 mg) was much higher than the 0.1 mg indicated by machine. CONCLUSIONS: In this study of Japanese male smokers, actual levels of nicotine intake bore little relation to advertised nicotine yield levels. Our study reinforces the need to warn consumers of inappropriate advertisements of nicotine yields, especially low yield brands.

Natural killer activity and its changes among participants in a smoking cessation intervention program--a prospective pilot study of 6 months' duration.

We examined the effect of smoking cessation on natural killer (NK) activity of peripheral blood lymphocytes in terms of a prospective study of 27 Japanese subjects who participated in a smoking cessation intervention program. This program was delivered by means of group-counseling offering 7 sessions of about 2 hours over 6 months to help smokers to discontinue the habit. Thirteen subjects ceased smoking (quitters), while 14 continued to smoke (cigarette smokers). NK activity before the intervention was correlated positively with age (correlation coefficient=0.46, P<0.05). NK activity remained almost constant among quitters, comparing the activity before and after the intervention, while it decreased among cigarette smokers although it was not statistically significant. In the subgroup analysis, NK activity increased among those aged less than 65 years, or urine cotinine levels over 800 ng/ml before the intervention, especially among quitters, but there were no statistical significances. Multiple regression analysis showed changes in NK activity were correlated significantly only with age (standard regression coefficient=-0.44, P<0.05). These findings suggest that smoking cessation intervention programs might have been more effective for younger than elder subjects in consideration of NK activity.

[The relationship between stages and biochemical markers of smoking. Workplace-based cross-sectional and longitudinal studies].

In order to clarify smokers' characteristics by "Stages of Change" based on Prochaska's transtheoretical model, we conducted cross-sectional and logitudinal studies with biochemical markers of smoking and smoking habits. In a workplace-based sample of 277 male smokers, we examined cross-sectionally the relationships between stages and biochemical markers of smoking which include expired carbon monoxide concentrations and urinary nicotine metabolite concentrations, and smoking habits which include the number of cigarettes smoked per day, yields of cigarettes, inhalation patterns, time to first morning cigarette, and quit attempts in the past. Additionally we examined longitudinally the relationship between stages and expired carbon monoxide concentrations, the number of cigarettes, and yields of cigarettes. In the cross-sectional study there were significant differences among stages on expired carbon monoxide concentrations (P = 0.006), urinary nicotine metabolite concentrations (P = 0.049), the number of cigarettes smoked per day (P = 0.001), and yields of cigarettes (P = 0.042) using analyses of variance. There were also significant differences among stages on time to first morning cigarette (P = 0.018) and quit attempts in the past (P < 0.001) using chi-square tests. In the longitudinal study for each level of elevation in stage during a one-year period, expired carbon monoxide concentrations decreased on an average of 2.3 ppm (P = 0.125) and the number of cigarettes smoked per day decreased on an average of 2.8 cigarettes per day (P = 0.07). However, the yields of cigarettes did not change during the one-year period.