Racial Differences in Circadian and Sleep Mechanisms for Nicotine Dependence, Craving, and Withdrawal

The number one preventable cause of death in the world is tobacco use. Cigarette smoking in particular, costs an estimated $300 billion due to expenses related to medical care and lost productivity. Despite similar smoking prevalence rates, blacks suffer disproportionately from smoking-related harms compared to whites.Sleep disparities such as shortened sleep duration, shorter circadian periodicity, earlier chronotype, and increased variability of sleep timing have been reported more frequently in blacks compared to whites. Given that poor sleep quality predicts relapse from smoking cessation programs, particularly among socioeconomically disadvantaged adults, sleep deficiencies and irregular timing of sleep may impact smoking craving and withdrawal symptoms over the course of the 24-hour day. Surprisingly, few studies have examined these temporal patterns of smoking and craving, and none with regard to sleep disruption, chronotype or racial disparities. A better understanding of these factors may explain heterogeneity within the smoking population, especially in minorities. Thus, the purpose of this proposal is to test the central hypothesis that the impact of chronotype and impaired sleep on cigarette usage as well as smoking dependence, urge/craving, and withdrawal depends on race.