Tobacco-induced sleep disturbances: A systematic review and meta- analysis

Even though tobacco-induced sleep disturbances (TISDs) have been reported in previous studies, the present article is the first meta-analysis quantitatively assessing the impact of tobacco on sleep parameters. We conducted a systematic review and meta-analysis of the studies comparing objective (i.e. polysomnography and actigraphy) and/or subjective sleep parameters in chronic tobacco smokers without comorbidities versus healthy controls. Studies were retrieved using PubMed, PsycINFO, and Web of Science. Differences are expressed as standardized mean deviations (SMD) and their 95% confidence intervals (95%CI). Fourteen studies were finally included into the review, among which ten were suitable for meta-analysis. Compared to healthy controls, chronic tobacco users displayed increased N1 percentage (SMD = 0.65, 95%CI: 0.22 to 1.07), N2 percentage (SMD = 1.45, 95%CI: 0.26 to 2.63), wake time after sleep onset (SMD = 6.37, 95%CI: 2.48 to 10.26), and decreased slow-wave sleep (SMD =-2.00, 95% CI:-3.30 to-0.70). Objective TISDs preferentially occurred during the first part of the night. Regarding subjective parameters, only the Pittsburgh Sleep Quality Index (PSQI) total score could be analyzed, with no significant between-groups difference (SMD = 0.53, 95%CI:-0.18 to 1.23). Smoking status should be carefully assessed in sleep medicine, while TISDs should be regularly explored in chronic tobacco users. (c) 2021 Elsevier Ltd. All rights reserved.

Automated summary

This meta-analysis found that chronic tobacco users had increased wake time after sleep onset, reduced slow-wave sleep, and disrupted sleep architecture compared to healthy controls. Objective tobacco-induced sleep disturbances were more prominent in the first part of the night, while subjective sleep quality did not show significant differences between groups.