Division of Cancer Prevention, National Cancer Control Institute, National Cancer Center, Goyang, Republic of Korea.
Department of Social and Preventive Medicine, Inha University College of Medicine, Incheon, Republic of Korea.
Nicotine Tob Res. 2022 Oct 26;24(11):1821-1828. doi: 10.1093/ntr/ntac133.
We examined the age- and sex-specific distributions of biomarkers of tobacco smoke exposure to determine the optimal cutoffs to distinguish smokers from non-smokers over the last 10 years in Korea, during which smoking prevalence and secondhand smoke (SHS) exposure declined due to changes in tobacco control policy.
We analyzed data from the Korea National Health and Nutrition Examination Survey on creatinine-adjusted urinary cotinine (2008-2018; 33 429 adults: 15 653 males and 17 776 females) and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL; 2016-2018; 6337 adults: 3091 males and 3246 females). We determined the optimal cutoffs and confidence intervals (CIs) to distinguish smokers from non-smokers using receiver operator characteristic curve analysis and bootstrapping (1000 resamples).
The optimal cutoff values of creatinine-adjusted urine cotinine and NNAL concentration were 20.9 ng/mg (95% CI: 20.8-21.0, sensitivity: 96.6%, specificity: 93.8%) and 8.9 pg/mg (95% CI: 8.8-8.9, sensitivity: 94.0%, specificity: 94.7%), respectively, in 2016-2018. The optimal cutoffs of both biomarkers increased with age and were higher in females than in males for NNAL concentration. In both sexes, the optimal cutoff of urine cotinine continuously declined over the study period.
The optimal cotinine cutoff declined along with smoking prevalence and levels of SHS exposure due to enforcement of tobacco control policies, including smoke-free ordinances and tax increases. Monitoring of biomarkers of tobacco exposure appears necessary for verification of smoking status and regulatory use.
Our results based on nationally representative data suggest that a large decrease in the optimal cutoff value of urine cotinine to distinguish smokers from non-smokers was caused by decreases in smoking prevalence and SHS exposure following enforcement of tobacco control policies over the last 10 years. We determined the optimal cutoff values of urine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), which were not previously reported in representative population in Asia, to enable more accurate estimation of exposure to tobacco smoke and proper assessment of disease risks. Gender- and age-specific differences in the optimal cutoffs require further study. Monitoring of biomarkers of tobacco smoke exposure seems necessary for verification of smoking status and regulatory use.
本研究旨在探讨过去 10 年来，由于控烟政策的改变导致韩国吸烟率和二手烟暴露率下降，不同年龄和性别的吸烟人群生物标志物的分布情况，以确定区分过去 10 年内吸烟者和非吸烟者的最佳切点。
本研究对 2008-2018 年韩国全国健康和营养检查调查中经过肌酐校正的尿液可替宁（33429 名成年人，其中 15653 名男性和 17776 名女性）和 4-（甲基亚硝胺）-1-（3-吡啶基）-1-丁醇（NNAL；6337 名成年人，其中 3091 名男性和 3246 名女性）的数据进行了分析。本研究使用受试者工作特征曲线分析和自举法（1000 次重采样）来确定区分吸烟者和非吸烟者的最佳切点及其置信区间（CI）。
2016-2018 年，肌酐校正尿液可替宁和 NNAL 浓度的最佳切点值分别为 20.9ng/mg（95%CI：20.8-21.0，灵敏度：96.6%，特异性：93.8%）和 8.9pg/mg（95%CI：8.8-8.9，灵敏度：94.0%，特异性：94.7%）。这两个生物标志物的最佳切点值均随年龄的增长而增加，且 NNAL 浓度的最佳切点值在女性中高于男性。在男性和女性中，尿液可替宁的最佳切点值在研究期间连续下降。
由于控烟政策的实施，包括无烟令和税收增加，可替宁的最佳切点值随吸烟率和二手烟暴露水平的下降而下降。监测烟草暴露的生物标志物对于验证吸烟状况和进行监管使用似乎是必要的。
本研究基于全国代表性数据，表明过去 10 年来，由于实施控烟政策导致吸烟率和二手烟暴露率下降，尿液可替宁区分吸烟者和非吸烟者的最佳切点值大幅下降。本研究确定了尿液中 4-（甲基亚硝胺）-1-（3-吡啶基）-1-丁醇（NNAL）的最佳切点值，此前在亚洲代表性人群中未报告过该值，以便更准确地估计烟草烟雾暴露量，并适当评估疾病风险。最佳切点值的性别和年龄差异需要进一步研究。监测烟草烟雾暴露的生物标志物对于验证吸烟状况和进行监管使用似乎是必要的。
