MedicalResearch.com: What are the main findings of the study?
Dr. Branstetter: This study demonstrated that the time to the first cigarette of the day after waking is associated with increased levels of a NNAL, a metabolite of a powerful tobacco-specific carcinogen, NNK — even after controlling for the total number of cigarettes smoked per day.
For years, the time to the first cigarette of the day after waking was one of several questions assessing nicotine dependence on the Fagerstrom Test for Nicotine Dependence (FTND), the gold standard questionnaire int he field. Over time, it was found that much of the predictive validity of the FTND was due to the time to first cigarette item. Researchers have found that single time to first cigarette item was highly correlated with other measures of nicotine dependence, and was predictive of more difficulty quitting smoking and increased intake of nicotine. Our current study demonstrates that this behavioral measure, is predictive of exposure to the cancer-causing components of cigarettes, regardless of the total number of cigarettes smoked per day. The results suggest that researchers, clinicians and smokers can assess the level of nicotine dependence and potential cancer risk by looking at the time to the first cigarette of the day after waking.
MedicalResearch.com: Were any of the findings unexpected?
Dr. Branstetter: Given our previous work, we did expect that time to first cigarette of the day after waking would relate to levels of NNAL among these smokers. However, the fact that time to first cigarette continued to predict NNAL levels even after controlling for a number of other potential explanatory factors, including the number of cigarettes smoker per day, number of years as a regular smoker, and having other smokers in the home, was somewhat surprising. The emerging evidence suggests that this single behavioral measure may be among the best at predicting nicotine dependence, risk exposure, and difficulty quitting.
MedicalResearch.com: What should clinicians and patients take away from your report?
Dr. Branstetter: The take home message is that how soon after waking up a smoker reaches for a cigarette is a very strong indicator of dependence and risk. Traditionally, clinicians have asked about the number of cigarettes smoked per day, which is still an important factor. However, the total number of cigarettes smoked may not always be the best question to ask to assess dependence or risk: for example, there is a non-linear relationship between cigarettes per day and blood levels of cotinine (the metabolite of nicotine). At some level after about 20 cigarettes per day, nicotine levels plateau such that someone smoking 25 cigarettes may have similar blood cotinine levels as someone smoking 40 cigarettes per day. Therefore, asking about the time to the first cigarette of the day after waking may tell clinicians (and patients) about the level of addiction, how difficult it may be to quit, and perhaps even the risk of lung cancer.
MedicalResearch.com: What recommendations do you have for future research as a result of this study?
Dr. Branstetter: The biggest question that we are looking into is what exactly the time to first cigarette is telling us. Our best guess is that time to first cigarette reflects how smokers are going about smoking their cigarettes. They are likely inhaling more deeply, holding their smoke longer, and taking more puffs per cigarette. Unfortunately, we don’t yet fully understand why time to first cigarette is so strongly related to these outcomes. Our future studies will be providing smokers with a small topography device that measures exactly how each cigarette, especially the first cigarette of the day, is smoked.
Time to First Cigarette and 4-(Methylnitrosamino)-1-(3-Pyridyl)-1-Butanol (NNAL) Levels in Adult Smokers; National Health and Nutrition Examination Survey (NHANES), 2007–2010
S. A. Branstetter, J. E. Muscat. Cancer Epidemiology Biomarkers & Prevention, 2013; 22 (4): 615 DOI: 10.1158/1055-9965.EPI-12-0842