Hecht Stephen S, Murphy Sharon E, Carmella Steven G, Zimmerman Cheryl L, Losey London, Kramarczuk Irene, Roe Mikel R, Puumala Susan S, Li Y Shelby, Le Chap, Jensen Joni, Hatsukami Dorothy K
Transdisciplinary Tobacco Use Research Center and College of Pharmacy, University of Minnesota, Minneapolis, USA.
J Natl Cancer Inst. 2004 Jan 21;96(2):107-15. doi: 10.1093/jnci/djh016.
Limited data are available on carcinogen uptake in smokers who reduce their smoking. To determine whether reducing the number of cigarettes smoked per day would lead to a corresponding reduction in carcinogen uptake, we measured levels of metabolites of the tobacco-specific lung carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) in the urine of smokers who reduced their smoking for up to 26 weeks.
We recruited 153 smokers, of whom 151 were randomly assigned to a reduction group or a waitlist group. In the reduction group of 102 smokers, we measured the metabolites 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) and its glucuronides (NNAL-Gluc) at two baseline times and at weeks 4, 6, 8, 12, and 26 after baseline. Smokers were then expected to reduce their number of cigarettes per day by 25% in weeks 0-2, 50% in weeks 2-4, and 75% in weeks 4-6 and to maintain the reduced level through week 26. In the waitlist group of 49 smokers, four baseline measurements over 7 weeks were made to assess the longitudinal stability of the metabolite measurements, and then the smokers began the reduction program. All statistical tests were two-sided.
For waitlist and reduction groups results were comparable. Statistically significant reductions in the lung carcinogen metabolites were observed at most intervals as smokers reduced the number of cigarettes smoked each day. However, the observed decreases were generally modest, always proportionally less than the reductions in cigarettes smoked per day, and sometimes transient. For example, among the 65 individuals in the reduction group who reduced cigarettes per day by 40% or more during weeks 4-12 after baseline, mean decreases in cigarettes per day were 53% (week 4), 74% (week 6), 75% (week 8), and 74% (week 12); whereas the corresponding mean reductions in NNAL plus NNAL-Gluc were 29%, 33%, 37%, and 29%. (P<.001 for all NNAL plus NNAL-Gluc values)
Statistically significant reductions in levels of urinary metabolites of a tobacco-specific lung carcinogen were achieved by reduction in smoking, but for most smokers, reductions were modest and transient.
关于减少吸烟量的吸烟者对致癌物摄取情况的数据有限。为了确定每天吸烟量的减少是否会相应地降低致癌物摄取量，我们测量了吸烟量减少长达26周的吸烟者尿液中烟草特异性肺致癌物4-(甲基亚硝胺基)-1-(3-吡啶基)-1-丁酮（NNK）的代谢物水平。
我们招募了153名吸烟者，其中151人被随机分配到减量组或候补名单组。在102名吸烟者的减量组中，我们在两个基线时间以及基线后的第4、6、8、12和26周测量了代谢物4-(甲基亚硝胺基)-1-(3-吡啶基)-1-丁醇（NNAL）及其葡糖苷酸（NNAL-葡糖苷）。吸烟者随后预计在第0 - 2周将每日吸烟量减少25%，在第2 - 4周减少50%，在第4 - 6周减少75%，并在第26周维持减少后的水平。在49名吸烟者的候补名单组中，在7周内进行了4次基线测量以评估代谢物测量的纵向稳定性，然后这些吸烟者开始减量计划。所有统计检验均为双侧检验。
候补名单组和减量组的结果具有可比性。随着吸烟者每天吸烟量的减少，在大多数时间间隔都观察到肺致癌物代谢物有统计学显著降低。然而，观察到的降低通常较为适度，总是按比例小于每日吸烟量的减少，并且有时是短暂的。例如，在减量组中，65名在基线后第4 - 12周期间每日吸烟量减少40%或更多的个体中，每日吸烟量的平均减少分别为5周时的53%（第4周）、74%（第6周）、75%（第8周）和74%（第12周）；而NNAL加NNAL-葡糖苷的相应平均降低分别为29%、33%、37%和29%。（所有NNAL加NNAL-葡糖苷值的P<0.001）
通过减少吸烟，烟草特异性肺致癌物的尿液代谢物水平在统计学上有显著降低，但对大多数吸烟者来说，降低是适度且短暂的。
