"Most importantly, we found that NNAL level was highest among people who smoked the soonest upon waking, regardless of the frequency of smoking and other factors that predict NNAL concentrations," Branstetter said. "We believe these people who smoke sooner after waking inhale more deeply and more thoroughly, which could explain the higher levels of NNAL in their blood, as well as their higher risk of developing oral or lung cancer. As a result, time to first cigarette might be an important factor in the identification of high-risk smokers and in the development of interventions targeted toward early-morning smokers."
The sooner a person smokes a cigarette upon waking in the morning, the more likely he or she is to acquire lung or oral cancer, according to Penn State researchers.
"We found that smokers who consume cigarettes immediately after waking have higher levels of NNAL -- a metabolite of the tobacco-specific carcinogen NNK -- in their blood than smokers who refrain from smoking a half hour or more after waking, regardless of how many cigarettes they smoke per day," said Steven Branstetter, assistant professor of biobehavioral health.
According to Branstetter, other research has shown that NNK (4-(methylnitrosamino)-1-[3-pyridyl]-1-butanone) induces lung tumors in several rodent species. Levels of NNAL (4-(methylnitrosamnino)-1-(3-pyridyl)-1-butanol) in the blood can therefore predict lung cancer risk in rodents as well as in humans. In addition, NNAL levels are stable in smokers over time, and a single measurement can accurately reflect an individual's exposure.
Branstetter and his colleague Joshua Muscat, professor of public health sciences, examined data on 1,945 smoking adult participants from the National Health and Nutrition Examination Survey who had provided urine samples for analysis of NNAL. These participants also had provided information about their smoking behavio
|Contact: Sara LaJeunesse|