|Black, White Teens Show Differences in Nicotine Metabolism
New research by scientists with the National Institute on Drug Abuse (NIDA),
National Institutes of Health, suggests that some of the racial and ethnic differences
underlying how adults’ bodies metabolize nicotine also are at work during adolescence.
The findings have implications for the way teens of different racial and ethnic
backgrounds are provided smoking cessation treatments. The study is published
in the January 2006 issue of Ethnicity and Disease.
“Previous research in adults showed that black smokers take in 30 percent more
nicotine per cigarette and take longer to rid their bodies of the drug, compared
to white smokers,” says NIDA Director Dr. Nora D. Volkow. “The current findings,
among the first on adolescent nicotine metabolism, reveal that these differences
are in effect during the teen years, as well.”
“Because nicotine plays an active role in smoking reinforcement, these variations
may influence early onset addiction to tobacco,” Dr. Volkow adds. “Thus, these
findings may constitute a strong warning to black youth to keep from smoking
in the first place. They also may explain why certain smoking cessation therapies
work better in some populations than in others, and therefore, which treatments
should be offered to which teens.”
A team of scientists led by Dr. Eric T. Moolchan, Director of NIDA's Teen Tobacco
Addiction Research Clinic in Baltimore, Maryland, recruited 61 white and 30 black
adolescent smokers to participate in the study.
The scientists measured the ratio of one nicotine breakdown product to another
to assess the rates at which the teens’ bodies disposed of the drug. The ratio
of the two metabolites was lower among black youth, indicating that nicotine/cotinine
metabolism was occurring more slowly in this group.
They also measured the ratio of one nicotine breakdown product (cotinine) to
the number of cigarettes smoked per day (CPD). Although black youth smoked significantly
fewer cigarettes per day — 15.1 cigarettes vs. 19.6 cigarettes for white youth — white
and black youth exhibited similar measures of nicotine dependence and blood cotinine
concentrations. The significantly higher cotinine-to-CPD ratio among black youth
confirmed the slower metabolism among black teens.
“Our findings support the hypothesis that racial and ethnic differences in nicotine
metabolism exist among adolescent smokers, with black teens smoking less but
being exposed to as much nicotine as white teens,” says Dr. Moolchan.
The findings also suggest that smoking rates may be only one of a number of
factors to consider when selecting appropriate treatments for smoking cessation. “An
important implication is that black youth may not be offered certain smoking
cessation therapies if those treatments are selected largely on the number of
cigarettes smoked per day,” says Dr. Volkow. “Thus, we need to look at aspects
of nicotine dependence other than consumption to guide the selection of appropriate
and effective therapies.”
The study results remained statistically significant after controlling for smoking
menthol cigarettes. Recent findings have suggested that menthol might increase
the addictiveness of tobacco, and that menthol may play a role in inhibiting
nicotine metabolism. Studies also have indicated that blacks show a preference
for menthol cigarettes compared to white smokers.
The National Institute on Drug Abuse is a component of the National Institutes
of Health, U.S. Department of Health and Human Services. NIDA supports most
of the world’s research on the health aspects of drug abuse and addiction.
The Institute carries out a large variety of programs to ensure the rapid dissemination
of research information and its implementation in policy and practice. Fact
sheets on the health effects of drugs of abuse and information on NIDA research
and other activities can be found on the NIDA home page at http://www.drugabuse.gov.
The National Institutes of Health (NIH) — The Nation's Medical Research
Agency — includes 27 Institutes and Centers and is a component of
the U. S. Department of Health and Human Services. It is the primary Federal
agency for conducting and supporting basic, clinical, and translational medical
research, and it investigates the causes, treatments, and cures for both common
and rare diseases. For more information about NIH and its programs, visit http://www.nih.gov.