RESUMO
BACKGROUND: While several studies assessed the relation between cigarette smoking and sleep, there are still very few studies assessing the effect of nicotine in cigarette smoking on sleep. AIM: This study aimed to compare higher vs lower nicotine levels in cigarette smoking on sleep quality. METHODS: We used data from the recently released dataset for the Randomized Trial of Reduced-Nicotine Standards for Cigarettes. We included three groups in the current study: the least nicotine concentration (i.e., 0.4 mg/g), a moderate nicotine concentration (i.e., 5.2 mg/g), and the highest nicotine concentration (i.e., 15.8 mg/g). For each participant, we included data regarding baseline and the last follow up at 6 weeks, where we compared insomnia, sleep problems, and awakening at night, in addition to different depression and affect scores. RESULTS: A total of 360 patients were included in this study, with a mean age of 42.4 (±13.4) years. For the three nicotine groups (i.e., 0.4 mg/g, 5.2 mg/g, and 15.8 mg/g), we included 119 (33%), 122 (34%), and 119 (33%) participants. Among the high-nicotine-dose group, the number of participants who had worsened sleep was significantly higher than the number of those who had improved sleep (p = 0.01) after 6 weeks of consumption, where 37 (31%) had worsened sleep score after 6 weeks while only 19 (16%) had improved score compared with baseline. CONCLUSION: While previous studies established a relation either between cigarette smoking and sleep or between nicotine patches and sleep, the present study is the first to establish that higher nicotine doses in cigarettes were associated with more sleep disturbances.