Sleep bruxism is associated with a rise in arterial blood pressure

Abstract

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'Hôpital du Sacré-Coeur de Montréal.

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.

Keywords: Sleep; blood pressure; polysomnography; rhythmic masticatory muscle activity; sleep bruxism; teeth grinding.

Figures

Figure 1

BP increase associated with RMMA/SB single episode. Sample of the 45-beat temporal window used for beat-to-beat BP analysis during an RMMA/SB episode. The vertical line depicts RMMA/SB onset as detected by the RM signal (right masseter EMG). The beat to beat blood pressure increase is represented by the BP signal. Additional signals included ECG, EOG, SANT (thoracic belt), and EEG.

Figure 2

BP increase associated with RMMA/SB cluster episode. RMMA/SB cluster example with 2 episodes.

Figure 3

Changes in DBP and SBP in the 4 categories. Significant increases in DBP and SBP compared to baseline were observed in the RMMA/SB categories Arousal alone; RMMA/SB +arousal; RMMA/SB + body movement; and RMMA/SB + body movement + arousal. Once increased, SBP, but not DBP, remained statistically significant for the duration of the analyzed temporal window. Vertical line represents RMMA/SB onset; (*) represents onset of statistical significance, P ≤ 0.05. Error bars ± 2 SEM.

Figure 4

Comparison of mean SBP and DBP increases among the 4 single RMMA/SB categories. Error bars ± SE.