Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Comparative Study
. 2017 Jul;26(7):1093-1099.
doi: 10.1158/1055-9965.EPI-16-0920. Epub 2017 Mar 6.

Low Cotinine Glucuronidation Results in Higher Serum and Saliva Cotinine in African American Compared to White Smokers

Sharon E Murphy  1 , Christopher J Sipe  2 , Kwangsoo Choi  2 , Leah M Raddatz  2 , Joseph S Koopmeiners  3 , Eric C Donny  4 , Dorothy K Hatsukami  5
Affiliations
Comparative Study

Low Cotinine Glucuronidation Results in Higher Serum and Saliva Cotinine in African American Compared to White Smokers

Sharon E Murphy et al. Cancer Epidemiol Biomarkers Prev. 2017 Jul.

Abstract

Background: Tobacco exposure is often quantified by serum or saliva concentrations of the primary nicotine metabolite, cotinine. However, average cotinine concentrations are higher in African Americans (AA) compared with Whites with similar smoking levels. Cotinine is metabolized by UGT2B10 and CYP2A6, and low UGT2B10 activity is common in AA, due to the prevalence of a UGT2B10 splice variant.Methods: UGT2B10 activity was phenotyped in 1,446 smokers (34% AA) by measuring the percentage of cotinine excreted as a glucuronide. Urinary total nicotine equivalents (TNE), the sum of nicotine and 6 metabolites, were determined to quantify smoking dose, and cotinine and 3'-hydroxycotinine were quantified in saliva (study 1) or serum (study 2).Results: Ninety-seven smokers (78% AA) were null for UGT2B10 activity, and the saliva and serum cotinine levels, after adjustment for TNE and cigarettes per day (CPD), were 68% and 48% higher in these smokers compared with nonnull smokers (P < 0.001). After adjustment for TNE and CPD, salivary cotinine was 35% higher, and serum cotinine 24% higher in AA versus White smokers, but with additional adjustment for UGT2B10 activity, there were no significant differences in saliva and serum cotinine concentrations between these two groups.Conclusions: UGT2B10 activity significantly influences plasma cotinine levels, and higher cotinine concentrations in AA versus White smokers (after adjustment for smoking dose) result from lower levels of UGT2B10-catalyzed cotinine glucuronidation by AA.Impact: UGT2B10 activity or genotype should be considered when using cotinine as a tobacco exposure biomarker, particularly in populations such as AA with high frequencies of UGT2B10 nonfunctional variants. Cancer Epidemiol Biomarkers Prev; 26(7); 1093-9. ©2017 AACR.

PubMed Disclaimer

Conflict of interest statement

Conflict of Interest Statement

We confirm that there are no known conflicts of interest associated with this publication and there has been no significant financial support for this work that could have influenced its outcome.

Figures

Figure 1
Figure 1
Nicotine metabolic pathways. Adapted from Murphy et al, Carcinogenesis (2014) 35 (11): 2526–2533. Used by permission of Oxford University Press.
See this image and copyright information in PMC

References

    1. Wagenknecht LE, Cutter GR, Haley NJ, Sidney S, Manolio TA, Hughes GH, et al. Racial differences in serum cotinine levels among smokers in the Coronary Artery Risk Development in (Young) Adults study. Am J Public Health. 1990;80:1053–56. - PMC - PubMed
    1. Caraballo RS, Giovino GA, Pechacek TF, Mowery PD, Richter PA, Strauss WJ, et al. Racial and ethnic differences in serum cotinine levels of cigarette smokers - Third National Health and Nutrition Examination Survey, 1988–1991. J Am Med Assoc. 1998;280:135–39. - PubMed
    1. Benowitz NL, Bernert JT, Caraballo RS, Holiday DB, Wang J. Optimal serum cotinine levels for distinguishing cigarette smokers and nonsmokers within different racial/ethnic groups in the United States between 1999 and 2004. Am J Epidemiol. 2009;169:236–48. - PubMed
    1. Jain RB. Trends in serum cotinine concentrations among daily cigarette smokers: data from NHANES 1999–2010. Sci Total Environ. 2014;472:72–77. - PubMed
    1. Jain RB. Serum cotinine and urinary 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanonol levels among non-Hispanic Asian American smokers and nonsmokers as compared to other race/ethnicities: data from NHANES 2011–2012. Chemosphere. 2015;120:584–91. - PubMed

Publication types

MeSH terms

LinkOut - more resources