By Theresa Ahearn
According to a new study from Faculté de Médicine Dentaire, Université de Montreal, and Hôpital du Sacré-Coeur de Montréal, Québec, sleep bruxism is associated with blood pressure fluctuations during sleep. Researchers in the study published in SLEEP the international journal for sleep and circadian science examined ten young healthy participants with sleep bruxism compared to nine non-bruxism subjects. In the trial, participants underwent three nights of a comprehensive sleep study, that included noninvasive monitoring of beat-to-beat blood pressure recordings and observation of Rhythmic Masticatory Muscle Activity (RMMA)4. RMMA is frequently observed during sleep in normal subjects and those with sleep bruxism.
Notably, the data from this study, when compared to the non-bruxers, supported the hypothesis that sleep bruxism is associated with a significant increase in both systolic and diastolic blood pressure as well as fluctuations in breathing4. Researchers also observed that arousals and body movements that occur with sleep bruxism can impact the magnitude of blood pressure surges in otherwise healthy subjects. The increase in blood pressure could be significant for sleep bruxism related to cortical arousals and sleep bruxism with cortical arousal with body movement4.
Though this study holds promise that sleep bruxism appears to be correlated to blood pressure surges, it was unclear whether the blood pressure surges were caused by, or merely associated with, the sleep bruxism event. The team concluded that there was no correlation found between the relationship of the electromyography (EMG) amplitude of the sleep bruxism episode and the magnitude of the blood pressure surge. Therefore, this study would need to be revisited with a larger subject population, over a longer period4.
Sleep Bruxism and its Link to Other Sleep Disorders
Though there is no direct cause of sleep bruxism, some evidence points to a possible link related to sleep arousals in which the cardiac and respiratory systems spontaneously increase during sleep1. The majority of sleep bruxism takes place during non-REM sleep, stages 1 and 2 of the sleep cycle. Though a small percentage of episodes can be observed during REM sleep1. Arousals during sleep are accompanied by increased muscle activity which could explain the tightening of the jaw muscles that happen with bruxism. Bruxism is also found in patients who suffer from sleep disorders such as sleep apnea, REM sleep disorder, and snoring3. It is assumed that the jaw movement in patients with sleep apnea could be the body’s unconscious reaction to collapsed airways or restricted airflow, though it is important to highlight this is only a hypothesis. While there is a correlation between sleep apnea and sleep bruxism the connection is still inconclusive. Sleep studies have developed several compelling possibilities about the relationship between sleep apnea and sleep bruxism, but the results of each study fail to identify a consistent sequence.
Sleep Disorders and Blood Pressure
Sleep disorders are a common health concern in today’s modern world and can have a significant impact on the quality of life. Sleep disorders trigger daytime sleepiness, irritability, and chronic sleep deprivation. Sleep bruxism is considered a sleep disorder. Most commonly, patients who have sleep bruxism also have another sleep disorder like sleep apnea or restless leg syndrome2. Further studies have shown that teeth grinding, in general, can often signal sleep apnea and vice versa. One theoretical explanation for the relationship between sleep apnea and sleep bruxism is that teeth grinding is the body’s reaction to trying to open the airways3]. The relationship between elevated blood pressure and sleep apnea has been well documented, though the relationship between sleep bruxism and elevated blood pressure continues to gain momentum. As aforementioned, considering the relationship between sleep bruxism and blood pressure remains uncertain, a larger long-term study would be needed to assess whether a significant blood pressure surge is present when sleep bruxism occurs alone. Long-term studies could also assess if the blood pressure changes associated with sleep bruxism impact the cardiovascular system over time.
It is common knowledge that disrupted sleep can impact cardiovascular health. The research conducted by Faculté de Médicine Dentaire, Université de Montreal, and Hôpital du Sacré-Coeur de Montréal, Québec, spotlights a possible correlation between sleep bruxism and elevated systolic and diastolic blood pressure. Though more research is warranted to determine what degree sleep bruxism contributes to hypertension or cardiovascular disease when presenting alone and over a longer span of time. Nonetheless, initiating early treatment for sleep bruxism could help reduce not just the risk to teeth, but cardiovascular health as well.
Theresa Ahearn is a freelance writer with clients spanning from academia to mass media. Beyond writing, she serves as a project manager at Oak Ridge National Laboratory, a multiprogram science, and technology laboratory sponsored by the U.S. Department of Energy. She earned her master’s degree from Central Connecticut State University in Organizational Development and bachelor’s degree in Communications from the New York Institute of Technology in New York, New York.
- Carra, M. C., Rompré, P. H., Kato, T., Parrino, L., Terzano, M. G., Lavigne, G. J., & Macaluso, G. M. (2011). Sleep bruxism and sleep arousal: an experimental challenge to assess the role of cyclic alternating pattern. Journal of oral rehabilitation, 38(9), 635-642.
- Lavigne, G. J., & Montplaisir, J. Y. (1994). Restless legs syndrome and sleep bruxism: prevalence and association among Canadians. Sleep, 17(8), 739-743.
- Mansukhani, M. P., Covassin, N., & Somers, V. K. (2019). Neurological sleep disorders and blood pressure: current evidence. Hypertension, 74(4), 726-732.
- Nashed, A., Lanfranchi, P., Rompré, P., Carra, M. C., Mayer, P., Colombo, R., ... & Lavigne, G. (2012). Sleep bruxism is associated with a rise in arterial blood pressure. Sleep, 35(4), 529-536.