Time to first cigarette of the day and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) in adult regular and non-daily smokers: (NHANES) 2007-10.

As the number of regular smokers has decreased over the last decade, the prevalence of light (<10 cigarettes per day) and non-daily smokers has increased. As the FDA continues to develop regulations for tobacco products, understanding factors related to toxin exposure in all smokers is essential. The present study evaluated the relation between the tobacco-specific carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), as measured by its metabolite, and patterns of heavy smoking (>10 cigarettes per day), light smoking and non-daily smoking and the time to the first cigarette of the day (TTFC), a robust predictor of nicotine addiction, cessation failure, sleep disruption and other health indicators. Findings from a sample of 352 smokers suggest that among intermittent, non-daily and light daily smokers, TTFC of the day was associated with higher levels of NNK metabolite, an effect which was mediated by urinary cotinine levels, but not by the number of cigarettes smoked per day. This suggests these groups of smokers may be puffing each cigarette more intensely, thus increasing nicotine and toxin exposure, despite fewer overall cigarettes. These findings provide further information regarding toxicant exposure associated with lower-frequency smoking and has implications for future regulatory research approaches with lowered nicotine cigarettes and other tobacco products.