accounted for a significant amount of the variance in the development of SUD among AI/AN (Ehlers et al., 2009; Wilhelmsen and Ehlers, 2005). Genetic factors involved in nicotine and cotinine metabolism may contribute to variations in the amount of daily tobacco consumption in several racial-ethnic groups (Benowitz et al., 2009). For instance, Hawaiian (Derby et al., 2008) and Canadian Native-Americans (Hukkanen et al., 2005; Schoedel et al., 2004) smokers exhibit increased activity of the cytochrome P450 2A6 (CYP2A6), the primary enzyme that inactivates nicotine to cotinine. This increased activity may lead them to increased daily tobacco consumption and vulnerability to develop nicotine dependence.
