The Oxygen Desaturation Index for Severity Assessment of Obstructive Sleep Apnea Associated With Cigarette Smoking

Abstract

Objectives: Nicotine stimulates release of neurotransmitters that regulate the sleep-wake cycle and thereby leads to insomnia. Smoking is associated with upper airway distress; however, its role in severe sleep-related breathing disorders remains controversial. In this study, we investigated the effects of smoking on obstructive sleep apnea (OSA).Methods: We investigated 1,163 patients diagnosed with OSA who underwent polysomnography between March 2020 and July 2022. We recorded details including smoking status (current, former, and non-smoker), demographics, questionnaire-related data, and polysomnography findings and performed univariate analysis to compare these variables between smokers and non-smokers. We also analyzed the correlation between smoking status and OSA severity. The risk of smoking on the severity of OSA was determined using logistic regression analysis.Results: Current and former smokers included 461 male (49.1%) and 10 female (4.4%) (<i>p</i>=0.001). Smokers had a high apnea-hypopnea index (AHI) and oxygen desaturation index (ODI) (<i>p</i><0.001), high arousal index (<i>p</i>=0.001), and severe daytime sleepiness (indicated by the Epworth Sleepiness Scale, <i>p</i><0.001). We observed no correlation between the AHI and the number of cigarettes smoked per day and the duration of smoking. Logistic regression analysis after adjustment for age, sex, body mass index, and alcohol consumption showed that smoking was a risk factor for ODI (ODI >15, odds ratio 1.33, <i>p</i>=0.04), and AHI was independent of smoking.Conclusions: Controversy regarding the severity of OSA with smoking has currently not been definitively determined. However, our results provide new evidence to support the association between smoking and the ODI, which few studies have investigated to date.