In a study published in the online edition of Addiction, UCSF School of Medicine researcher Mark Rubinstein, MD, and his team found that slower metabolism of nicotine may increase susceptibility to dependence by increasing nicotine exposure and nicotine effects on the developing brain in teens.
The study, Nicotine Metabolism and Addiction among Adolescent Smokers Addiction, is according to Rubinstein the first to employ labeled cotinine (a byproduct of nicotine which is chemically inactive) as a means of measuring nicotine metabolism in adolescent smokers. This allowed researches to study even very light and non-daily smokers.
This was really interesting because it is the opposite of what is found in most studies of adult smokers.Mark Rubinstein, MD
“We looked at rates of nicotine metabolism in 164 adolescent smokers and found that slower metabolism was associated with more self-reported addiction and more cigarettes smoked,” Rubinstein said. “The brains of slower metabolizers are likely being exposed to greater amounts of nicotine for a longer period of time.”
“This was really interesting because it is the opposite of what is found in most studies of adult smokers, in which faster metabolizers smoke more and are thought to be more addicted,” Rubinstein said. The findings highlight the importance of studying smokers at various stages of smoking progression, he added.
UCSF School of Medicine co-authors of the research included Anna-Barbara Moscicki, MD, professor; Saunak Sen, PhD, MS, assistant professor in residence; and Neal Benowitz, MD, professor in residence.
The study was supported by the Clinical Research Services (CRS) program managed by UCSF’s Clinical and Translational Science Institute (CTSI). At the Pediatric Clinical Research Center, one of eight clinical sites managed by the CTSI CRS in the Bay Area, adolescent participants were housed for nine hours. When they arrived in the morning, they ingested labeled cotinine, and eight hours later, their saliva was tested to determine how quickly they had metabolized nicotine.
UCSF's CTSI is a member of the Clinical and Translational Science Awards network funded through the National Center for Advancing Translational Sciences at the National Institutes of Health (Grant Number UL1 TR000004). Under the banner of Accelerating Research to Improve Health, the Institute provides a wide range of services for researchers, and promotes online collaboration and networking tools such as UCSF Profiles.