The Relation Between Daytime Sleepiness and Awake and Sleep Bruxism Report in Patients With Obstructive Sleep Apnoea

Objective: To assess the relationship between daytime sleepiness and both self-reported awake bruxism (AB) and sleep bruxism (SB) in patients with different severities of obstructive sleep apnoea (OSA). Material and Methods: One hundred and seventy-four participants (female = 33.9%; mean age [+/- SD] = 55.1 +/- 12.3 years) with polygraphy-confirmed OSA underwent a self-reported assessment for both awake and SB and daytime sleepiness, using the BRUX scale questionnaire and Epworth sleepiness scale, respectively. Three BRUX scale sum scores were computed for each patient: total sum score, AB sum score and SB sum score. To assess OSA severity, the apnoea-hypopnoea index and minimal oxygen saturation (MinSat) were considered. Correlations between daytime sleepiness, BRUX scale scores and OSA severity were assessed using Pearson's test. In addition, a multiple linear regression analysis model was used to assess the predictive effect of both self-reported awake and SB and OSA severity on daytime sleepiness. Results: A significant, but weak correlation emerged between daytime sleepiness and the BRUX scale total sum score (r = 0.155; p < 0.05), the awake BRUX scale sum score (r = 0.174; p < 0.05) and MinSat (r = 0.194; p < 0.01). No significant correlations were found between OSA severity and any other variables. The multiple linear regression analysis showed that only the awake BRUX scale sum score had a positive predictive association with daytime sleepiness (B = 0.485; [95% CI = 0.076; 0.936]; p = 0.027). Conclusions: Within the limitations of this study, in individuals with OSA, self-reported AB showed a predictive effect for daytime sleepiness, while no significant correlation between daytime sleepiness and OSA severity emerged.