University of California, San Francisco, CA, USA.
Cancer Epidemiol Biomarkers Prev. 2012 Jun;21(6):934-42. doi: 10.1158/1055-9965.EPI-11-1178. Epub 2012 Apr 6.
The prevalence of tobacco use, both cigarette smoking and smokeless, including iqmik (homemade smokeless tobacco prepared with dried tobacco leaves mixed with alkaline ash), and of tobacco-related cancer is high in Alaskan Native people (AN). To investigate possible mechanisms of increased cancer risk we studied levels of nicotine and tobacco-specific nitrosamines (TSNA) in tobacco products and biomarkers of tobacco toxicant exposure in Southwestern AN people.
Participants included 163 cigarette smokers, 76 commercial smokeless tobacco, 20 iqmik, 31 dual cigarette smokers and smokeless tobacco, and 110 nontobacco users. Tobacco use history, samples of tobacco products used, and blood and urine samples were collected.
Nicotine concentrations were highest in cigarette tobacco and TSNAs highest in commercial smokeless tobacco products. The AN participants smoked on average 7.8 cigarettes per day. Nicotine exposure, assessed by several biomarker measures, was highest in iqmik users, and similar in smokeless tobacco and cigarette smokers. TSNA exposure was highest in smokeless tobacco users, and polycyclic aromatic hydrocarbon exposure was highest in cigarette smokers.
Despite smoking fewer cigarettes per day, AN cigarette smokers had similar daily intake of nicotine compared to the general U.S. population. Nicotine exposure was greatest from iqmik, likely related to its high pH due to preparation with ash, suggesting high addiction potential compared to other smokeless tobacco products. TSNA exposure was much higher with smokeless tobacco than other product use, possibly contributing to the high rates of oral cancer.
Our data contribute to an understanding of the high addiction risk of iqmik use and of the cancer-causing potential of various forms of tobacco use among AN people.
在阿拉斯加原住民中，无论是香烟还是无烟烟草（包括用干烟叶和碱性灰混合制成的 iqmik）的吸烟率以及与烟草相关的癌症发病率都很高。为了研究癌症风险增加的可能机制，我们研究了西南地区阿拉斯加原住民中烟草制品中的尼古丁和烟草特异性亚硝胺（TSNA）水平以及烟草毒剂暴露的生物标志物。
参与者包括 163 名香烟吸烟者、76 名商业无烟烟草使用者、20 名 iqmik 使用者、31 名香烟和无烟烟草双重使用者以及 110 名非烟草使用者。收集了烟草使用史、使用的烟草制品样本以及血液和尿液样本。
尼古丁浓度在香烟烟草中最高，TSNA 在商业无烟烟草制品中最高。参与者平均每天吸烟 7.8 支。通过几种生物标志物测量评估的尼古丁暴露量在 iqmik 使用者中最高，与无烟烟草和香烟吸烟者相似。TSNA 暴露量在无烟烟草使用者中最高，多环芳烃暴露量在香烟吸烟者中最高。
尽管每天吸烟较少，但与美国一般人群相比，阿拉斯加原住民香烟吸烟者的尼古丁日摄入量相似。从 iqmik 中摄入的尼古丁最多，可能与其由于准备过程中使用灰分而导致的高 pH 值有关，这表明与其他无烟烟草产品相比，它具有更高的成瘾潜力。与其他产品相比，使用无烟烟草导致的 TSNA 暴露量要高得多，这可能是导致口腔癌发病率高的原因之一。
我们的数据有助于了解 iqmik 使用的高成瘾风险以及阿拉斯加原住民中各种形式的烟草使用的致癌潜力。
