Sleep quality in cigarette smokers: Associations with smoking-related outcomes and exercise

Introduction: Compared to the general population, cigarette smokers report poorer sleep quality. Poor sleep quality in cigarette smokers is associated with greater nicotine dependence. While exercise is known to improve sleep quality in the general population, less is known about how exercise effects sleep in those who smoke. The goal of this study was to explore the relationships between exercise, sleep, and smoking in cigarette smokers. Methods: Data on sleep quality (Insomnia Severity Index (ISI) and Pittsburgh Sleep Quality Index (PSQI)), smoking-related outcomes (e.g., cigarettes/day, Fagerstrom Test for Nicotine Dependence, Minnesota Nicotine and Withdrawal Scale, and Questionnaire of Smoking Urges) and exercise (Fitbit activity measures) were collected for 32 participants (63% female, mean age 30.3 ± 1.0 years) participating in a 12-week clinical research study. Analyses included simple linear regression models. Results: Overall, participants reported poor sleep quality at baseline (PSQI > 5). Poorer sleep quality at baseline was associated with increased withdrawal (β = 1.63 ± 0.53, p = 0.0043), craving (β = 0.51 ± 0.43, p = 0.2471), and total smoking urges (β = 1.10 ± 0.41, p = 0.0118). During follow-up (i.e., from baseline to week 12), a daily increase in exercise was associated with improved sleep quality over the same time period (PSQI: β = −0.82 ± 0.35, p = 0.0379). Conclusion: Our data suggest that better sleep quality may be associated with lower levels of withdrawal, craving, and smoking urges. Further, exercise may be associated with better sleep quality in cigarette smokers. Future work should explore how increasing exercise and improving sleep quality could inform future smoking cessation interventions.