RESUMO
Objective/Background: Sleep disturbances are considered among the negative consequences of smoking. However, the relationship between sleep quality and smoking among young adults, a population in which the prevalence of smoking is highest, has scarcely been examined. The current study aimed at examining differences in sleep indices, assessed by both subjective and objective (actigraphy) measures, between smokers and nonsmokers, and whether such differences are associated with levels of nicotine dependence. Participants: Eighty-six young (19-28 years old) volunteers, of them 46 nonsmokers (69.6% women) and 40 regular smokers (70.0% women) smoking at least 10 cigarettes a day. Methods: The participants completed the State-Trait Anxiety Inventory, Beck Depression Inventory, Brief Questionnaire on Smoking Urges, the Fagerstrom Test for Nicotine Dependence, and the Pittsburgh Sleep Quality Index. Their sleep was monitored objectively for one week using an actigraph. Results: Smokers' self-reported sleep quality was similar to that of nonsmokers. However, actigraphy data pointed to lower sleep continuity in smokers compared to nonsmokers as reflected by increased wake time after sleep onset (Mean ± SD: 18.56 ± 15.29 vs. 11.21 ± 11.19, p < .01) and decreased sleep efficiency (Mean ± SD: 95.63 ± 3.53 vs. 97.23 ± 2.62, p < .012). Total sleep time and sleep onset latency did not differ between the groups. Notably, severity of nicotine dependence was negatively associated with sleep efficiency (ß = -.32; p < .05). Conclusion: Young adult smokers have lower sleep continuity without necessarily subjectively experiencing their sleep as poor. Nevertheless, their lower sleep continuity is related to their level of nicotine dependence.
