Nicotine Metabolite Ratio Predicts Smoking Topography and Carcinogen Biomarker Level

Background: Variability in smoking behavior is partly attributable to heritable individual differences in nicotine clearance rates. This can be assessed as the ratio of the metabolites cotinine and 3'-hydroxycotinine (referred to as the nicotine metabolism ratio; NMR). We hypothesized that faster NMR would be associated with greater cigarette puff volume and higher levels of total 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), a carcinogen biomarker. Methods: Current smokers (n = 109) smoked one of their preferred brand cigarettes through a smoking topography device and provided specimens for NMR and total NNAL assays. Results: Faster nicotine metabolizers (third and fourth quartiles versus first quartile) based on the NMR exhibited significantly greater total puff volume and total NNAL; the total puff volume by daily cigarette consumption interaction was a significant predictor of total NNAL level. Conclusion: A heritable biomarker of nicotine clearance predicts total cigarette puff volume and total NNAL. Impact: If validated, the NMR could contribute to smoking risk assessment in epidemiologic studies and potentially in clinical practice. Cancer Epidemiol Biomarkers Prev; 20(2); 234-8. 2011 AACR.