Sleep Bruxism Is Associated with a Rise in Arterial Blood Pressure

Study Objectives: Sleep bruxism (SB) is a movement disorder identified by grinding of teeth and rhythmic masticatory muscle activity (RMMA). RMMA is associated with body movements and cortical arousals. Increases in autonomic sympathetic activities that characterize sleep cortical arousal precede RMMA/SB. Based on these findings, this study examined whether RMMA/SB episodes are also associated with significant changes in arterial blood pressure (BP). Design: Participants underwent 3 nights of full polysomnography that included noninvasive beat-to-beat BP recording. Single RMMA/SB episodes and arousal episodes were analyzed in stage 2 sleep and categorized as: (i) RMMA/SB + arousal; (ii) RMMA/SB + body movement; (iii) RMMA/SB + arousal + body movement; or (iv) arousal alone. Sleep and RMMA/SB data were compared to a Non SB group. RMMA/SB clusters (RMMA/SB episodes <= 30 sec apart) were also analyzed. Setting: Sleep Laboratory at l'Hopital du Sacre-Coeur de Montreal. Participants: Ten young, healthy participants with SB (mean age = 26 +/- 1.8 years) and 9 without SB (mean age = 29 +/- 1.2 years). Interventions: N/A Measurements and Results: BP increased with all RMMA/SB and arousal episodes (P <= 0.05). The average maximum BP surges (systolic/diastolic +/- SE mm Hg) were: 25.6 +/- 3.3/12.6 +/- 2.0 for RMMA/SB + arousal; 30.1 +/- 1.7/19.1 +/- 1.9 for RMMA/SB + body movement; 26.0 +/- 2.8/15.1 +/- 2.0 for RMMA/SB + arousal + body movement; 19.4 +/- 2.3/8.9 +/- 1.2 for arousal alone; and for RMMA/SB clusters: Episode: 1:26.2 +/- 8.7/16.4 +/- 5.7; Episode 2:21.1 +/- 7.9/12.6 +/- 6.4. Conclusion: Rhythmic masticatory muscle activity/sleep bruxism (RMMA/SB) is associated with blood pressure fluctuations during sleep. Arousals and body movements often occur with RMMA/SB and can impact the magnitude of this BP surge.