Dataset Information

A Comparison of Direct and Indirect Analytical Approaches to Measuring Total Nicotine Equivalents in Urine.

ABSTRACT: Background: Total nicotine equivalents (TNE), the sum of nicotine and metabolites in urine, is a valuable tool for evaluating nicotine exposure. Most methods for measuring TNE involve two-step enzymatic hydrolysis for indirect quantification of glucuronide metabolites. Here, we describe a rapid, low-cost direct LC/MS assay.Methods: In 139 smokers' urine samples, Bland-Altman, correlation, and regression analyses were used to investigate differences in quantification of nicotine and metabolites, TNE, and nicotine metabolite ratio (NMR) between direct and indirect LC/MS methods. DNA from a subset (n = 97 smokers) was genotyped for UGT2B10*2 and UGT2B17*2, and the known impact of these variants was evaluated using urinary ratios determined by the direct versus indirect method.Results: The direct method showed high accuracy (0%-9% bias) and precision (3%-14% coefficient of variation) with similar distribution of nicotine metabolites to literary estimates and good agreement between the direct and indirect methods for nicotine, cotinine, and 3-hydroxycotinine (ratios 0.99-1.07), but less agreement for their respective glucuronides (ratios 1.16-4.17). The direct method identified urinary 3HC+3HC-GLUC/COT as having the highest concordance with plasma NMR and provided substantially better estimations of the established genetic impact of glucuronidation variants compared with the indirect method.Conclusions: Direct quantification of nicotine and metabolites is less time-consuming and less costly, and provides accurate estimates of nicotine intake, metabolism rate, and the impact of genetic variation in smokers.Impact: Lower cost and maintenance combined with high accuracy and reproducibility make the direct method ideal for smoking biomarker, NMR, and pharmacogenomics studies. Cancer Epidemiol Biomarkers Prev; 27(8); 882-91. ©2018 AACR.

SUBMITTER: Taghavi T

PROVIDER: S-EPMC6072604 | biostudies-literature | 2018 Aug

REPOSITORIES: biostudies-literature

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A Comparison of Direct and Indirect Analytical Approaches to Measuring Total Nicotine Equivalents in Urine.

Taghavi Taraneh T Novalen Maria M Lerman Caryn C George Tony P TP Tyndale Rachel F RF

Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology 20180531 8

<b>Background:</b> Total nicotine equivalents (TNE), the sum of nicotine and metabolites in urine, is a valuable tool for evaluating nicotine exposure. Most methods for measuring TNE involve two-step enzymatic hydrolysis for indirect quantification of glucuronide metabolites. Here, we describe a rapid, low-cost direct LC/MS assay.<b>Methods:</b> In 139 smokers' urine samples, Bland-Altman, correlation, and regression analyses were used to investigate differences in quantification of nicotine and ...[more]

PMID: 29853480

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Project description:IntroductionDual use of electronic cigarettes (e-cigarettes) and combustible cigarettes is a major public health issue. It is generally accepted that exclusive e-cigarette use is less harmful than exclusive combustible cigarette use, but most e-cigarette users continue to smoke combustible cigarettes as well. To what extent the use of e-cigarettes reduces harm in people who continue to smoke combustible cigarettes has been debated. The aim of this study was to explore the utility of biomarkers as measures of dual use.MethodsIn two human studies of participants who used e-cigarettes only or both combustible cigarettes and e-cigarettes, we measured urine concentrations of the metabolites of nicotine (total nicotine equivalents) as well as two biomarkers of tobacco exposure: 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), a tobacco-specific carcinogen metabolite, and nicotelline, a tobacco alkaloid not found in significant concentrations in e-cigarette products.ResultsThe presence of nicotine metabolites indicates either e-cigarette or combustible cigarette use. Nicotelline (half-life of 2-3 hours) indicates recent combustible cigarette use and NNAL (half-life of 10 days or more), indicates combustible cigarette use occurring within several weeks prior to sample collection.ConclusionsNicotelline and NNAL are useful biomarkers for combustible tobacco use in users e-cigarettes. The application of these biomarkers provides a tool to help assess whether, or to what extent, dual use of e-cigarettes and combustible cigarettes reduces harm compared to sole use of combustible cigarettes. These biomarkers can also verify exclusive use of e-cigarettes over short (24 hour) or long (several week) time periods.ImplicationsTo what extent dual use of e-cigarettes and combustible cigarettes reduce harm compared to smoking combustible cigarettes only is of considerable public health interest. We show that the levels of the minor tobacco alkaloid nicotelline and the nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) are extremely low in electronic cigarette fluids. The urine biomarkers nicotelline and the NNK metabolite 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) are indicative of cigarette smoking and can be used to assess recent and past smoking in dual users.

Project description:BackgroundTo reach non-participants, reluctant to undergo clinician-based cervical cancer screening and vaginal self-sampling, urine collection for high-risk human papillomavirus detection (hrHPV) may be valuable. Using two hrHPV DNA assays, we evaluated the concordance of hrHPV positivity in urine samples in comparison with vaginal self-samples and cervical cytology samples taken by the general practitioner (GP). We also studied women's acceptance of urine collection and preferences towards the different sampling procedures.MethodsOne hundred fifty paired self-collected urine and vaginal samples and GP-collected cervical cytology samples were obtained from 30 to 59-year-old women diagnosed with ASC-US within the Danish cervical cancer screening program. After undergoing cervical cytology at the GP, the women collected first-void urine and vaginal samples at home and completed a questionnaire. Each sample was hrHPV DNA tested by the GENOMICA CLART® and COBAS® 4800 assays. Concordance in hrHPV detection between sample types was determined using Kappa (k) statistics. Sensitivity and specificity of hrHPV detection in urine was calculated using cervical sampling as reference.ResultsWith the COBAS assay, urine showed good concordance to the vaginal (k = 0.66) self-samples and cervical samples (k = 0.66) for hrHPV detection. The corresponding concordance was moderate (k = 0.59 and k = 0.47) using CLART. Compared to cervical sampling, urinary hrHPV detection had a sensitivity of 63.9% and a specificity of 96.5% using COBAS; compared with 51.6 and 92.4% for CLART. Invalid hrHPV test rates were 1.8% for COBAS and 26.9% for CLART. Urine collection was well-accepted and 42.3% of the women ranked it as the most preferred future screening procedure.ConclusionsUrine collection provides a well-accepted screening option. With COBAS, higher concordance between urine and vaginal self-sampling and cervical sampling for hrHPV detection was found compared to CLART. Urinary hrHPV detection with COBAS is feasible, but its accuracy may need to be improved before urine collection at home can be offered to non-participants reluctant to both cervical sampling and vaginal self-sampling.

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Dataset Information

A Comparison of Direct and Indirect Analytical Approaches to Measuring Total Nicotine Equivalents in Urine.

Publications

A Comparison of Direct and Indirect Analytical Approaches to Measuring Total Nicotine Equivalents in Urine.

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