The Relationship between Sleep Bruxism Intensity and Renalase Concentration—An Enzyme Involved in Hypertension Development

Abstract

Background and objectives: Renalase, a novel amine oxidase, is involved in the development of hypertension. Sleep bruxism (SB) is a sleep-related behavior characterized by rhythmic or non-rhythmic activity of the masticatory muscles, which leads to the mechanical wear of teeth, pain in the masticatory muscles, and disturbed sleep. Recent studies indicate that SB plays a role in increased blood pressure. Therefore, this study aimed to determine the relationship between sleep bruxism intensity and renalase concentration, which may help in the future to elucidate the pathogenesis of hypertension and other cardiovascular disorders. Material and methods: SB was evaluated in 87 adult patients using single-night diagnostic polysomnography with video and audio recordings, and the episodes of bruxism were scored according to the standards of the American Academy of Sleep Medicine. The levels of serum renalase were measured in the patients using enzyme-linked immunosorbent assay kits. Results: SB (Bruxism Episode Index (BEI) ≥2) was diagnosed in 54% (n = 47) of the studied population, and the mean concentration of renalase was found to be decreased in the hypertensive group compared with the normotensive group (133.33 ± 160.71 vs 219.23 ± 220.58, p = 0.047). In addition, a linear negative correlation was observed between the renalase concentration and the body mass index (BMI) in the SB group (r = 0.38, p < 0.05) but not in controls. Thus, higher BEI and higher BMI were identified as factors independently associated with the lower concentration of renalase, but only in the group of patients which had a blood renalase concentration of >212.5 ng/mL. Conclusion: There exists an association between renalase concentration and SB intensity, and further studies are needed to clarify the role of renalase in the pathogenesis of hypertension and other cardiovascular disorders.

Cardiovascular Implications of Sleep Bruxism—A Systematic Review with Narrative Summary and Future Perspectives

“…Most of the revised papers investigated bruxism events during sleep with polysomnography [ 24 , 25 , 26 , 29 , 32 , 33 , 34 , 35 ], three studies collected data using polygraphy devices [ 27 , 28 , 30 ] and one employed a sleep bruxism monitoring system composed of two accelerometers, an infrared camera, electroencephalography, electromyography and electrocardiography devices [ 31 ].…”

“…Through analysis, we identified publications on autonomic function in bruxers [ 25 , 27 , 31 ]. Some studies focused on blood pressure in the context of sleep bruxism [ 29 , 30 , 32 , 35 ]; others evaluated changes in heart rate (heart rate variability, HRV) [ 24 , 26 , 28 , 33 ] in sleep bruxers. One study determined inflammatory markers and hormonal disturbances as cardiovascular risk factors [ 34 ].…”

“…BP recordings were based on beat-to-beat measures using finger cuffs [ 29 ]. The publication by Martynowicz et al [ 32 ] presented some information about the background of renalase involvement in hypertension pathogenesis and indicated that there is an association between renalase concentration and sleep bruxism severity. The next study by Martynowicz et al [ 30 ] was designed to evaluate the intensity of SB in a hypertensive group of patients compared with normotensives.…”

“…The reviewed literature was also heterogeneous with respect to SB diagnostic criteria. Five recent studies [ 30 , 32 , 33 , 34 , 35 ] defined RMMA/SB events depending on EMG recordings in line with AASM standards [ 10 ]. On the other hand, Nashed et al [ 29 ], Huynh et al [ 27 , 28 ] and Kato et al [ 26 ] diagnosed SB according to validated research criteria demonstrated by Lavigne et al [ 38 ].…”

Renalase and hypertension—demographic and clinical correlates in obstructive sleep apnea

“…OSA (AHI ≥ 5) was diagnosed in 71.42% (n = 80) of the studied population. The mild (AHI 5-15), moderate (AHI [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30], and severe (AHI ≥ 30) OSA were diagnosed in 28.57% The statistically significant negative correlation was observed between AHI and renalase in the entire study group (r = − 0.19, p = 0.039; Fig. 2), in males (r = − 0.29, p = 0.046), and in the group of age < 60 (r = − 0.20; p = 0.042).…”