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Background: Polysomnography (PSG) is the gold standard for sleep bruxism (SB) assessment, it is expensive, not widely accessible, and time-consuming., Objective: Given the increasing prevalence of SB, there is a growing need for an alternative, readily available, reliable and cost-effective diagnostic method. This study aimed to evaluate the diagnostic validity of portable respiratory polygraphy (PRPG) compared with PSG for SB diagnosis., Methods: One hundred and three subjects underwent simultaneous examinations using PRPG (NOX T3, NOX Medical) and PSG (NOX A1, NOX Medical) in a sleep laboratory., Results: The mean Bruxism Episodes Index (BEI) measured by PRPG was 4.70 ± 3.98, whereas PSG yielded a mean BEI of 3.79 ± 3.08. The sensitivity for detecting sleep bruxism (BEI >2) by PRPG was 48.3%, with a specificity of 81.2%. The positive predictive value was estimated at 51.9%, and the negative predictive value at 78.9%. However, when distinguishing between mild bruxism (BEI >2 < 4) and severe bruxism (BEI >4), PRPG demonstrated a sensitivity of 77.8% and 68.3% and a specificity of 48.6% and 71.4%, respectively., Conclusion: Polysomnography continues to be the SB diagnostic gold standard tool, as the sensitivity and specificity of PRPG are significantly lower when compared with PSG. Nevertheless, PRPG could serve as an alternative tool for SB screening or diagnosis, despite its limitations. Furthermore, our data indicate that comorbidities such as sleep apnea and sleep quality do not influence the diagnostic accuracy of PSG, suggesting its potential as a screening instrument in individuals with other sleep disorders., (© 2024 John Wiley & Sons Ltd.)

Associations between obstructive sleep apnea (OSA) and sleep bruxism (SB) are the subject of discussion but have not been confirmed definitively. Therefore, the objective of this meta-analysis was to examine the relationship between OSA and SB. This systematic review was conducted in accordance with PRISMA 2020 guidelines. PubMed, Embase and Web of Science were screened up to February 2024. The risk of bias was assessed with the Joanna Briggs Institute tool. 2260 records were identified, but only 14 studies were included. The odds of SB presence in OSA did not differ from the control group (OR: 1.23, 95 % CI: 0.47-3.20). The chance of SB compared to controls also did not differ in mild OSA (OR: 1.56, 95 % CI: 0.76-3.18), in moderate OSA (OR: 1.51, 95 % CI: 0.77-2.94) and in severe OSA (OR: 1.50, 95 % CI: 0.68-3.29). Additionally, the odds of SB were not increased in moderate OSA in comparison to mild OSA (OR: 1.14, 95 % CI: 0.63-2.94), in severe OSA compared to moderate OSA (OR: 1.31, 95 % CI: 0.61-2.79) or in severe OSA compared to mild OSA (OR = 1.42, 95 % CI: 0.69-2.93). The presence of SB in OSA did not differ between genders (OR: 2.14, 95 % CI: 0.65-7.05). The quality of the major studies included is low; therefore, the noted lack of correlation between OSA and SB may require further research. The relationship between OSA and SB seems to be multi-faceted. Presented results should not exempt clinicians from exact diagnosis of concomitant sleep conditions in OSA subjects., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

The objective of the current study was to evaluate the clinical utility of bruxism episode index in predicting the level of masticatory muscle pain intensity. The study involved adults (n = 220) recruited from the Outpatient Clinic of Temporomandibular Disorders at the Department of Experimental Dentistry, Wroclaw Medical University, during the period 2017-2022. Participants underwent medical interview and dental examination, focusing on signs and symptoms of sleep bruxism. The intensity of masticatory muscle pain was gauged using the Numeric Rating Scale. Patients identified with probable sleep bruxism underwent further evaluation through video-polysomnography. Statistical analyses included the Shapiro-Wilk test, Spearman's rank correlation test, association rules, receiver operating characteristic curves, linear regression, multivariate regression and prediction accuracy analyses. The analysis of correlation and one-factor linear regression revealed no statistically significant relationships between bruxism episode index and Numeric Rating Scale (p > 0.05 for all analyses). Examination of receiver operating characteristic curves and prediction accuracy indicated a lack of predictive utility for bruxism episode index in relation to masticatory muscle pain intensity. Multivariate regression analysis demonstrated no discernible relationship between bruxism episode index and Numeric Rating Scale across all examined masticatory muscles. In conclusion, bruxism episode index and masticatory muscle pain intensity exhibit no correlation, and bruxism episode index lacks predictive value for masticatory muscle pain. Clinicians are advised to refrain from employing the frequency of masticatory muscle activity as a method for assessing the association between masticatory muscle pain and sleep bruxism., (© 2024 The Author(s). Journal of Sleep Research published by John Wiley & Sons Ltd on behalf of European Sleep Research Society.)

Exposure to tobacco smoke (ETS) is one of the main risk factors for cardiovascular disease (CVD). Renalase is a protein that may play a role in the pathogenesis of CVD. The aim of the study was to assess the relationship between ETS and serum renalase concentration. A group of 109 patients was recruited for this study (49.7 ± 14.7 years). In accordance with the questionnaire, patients were divided into the following subgroups: subgroup A- declaring themselves active smokers (n = 36), subgroup B- declaring themselves non-smokers and exposed to environmental tobacco smoke (n = 35), subgroup C- declaring themselves non-smokers and not exposed to environmental tobacco smoke (n = 38). The same patients were divided based on cotinine concentration into the following subgroups: subgroup D- active smokers (n = 42), subgroup E- non-smokers exposed to environmental tobacco smoke (n = 66), and subgroup F- non-smokers not exposed to environmental tobacco smoke (n = 1). Serum cotinine concentration and serum renalase concentration were measured using ELISA tests. Serum renalase concentration was statistically significantly higher in subgroup C than in subgroups A and B and in subgroup E and F than in D. There was a negative correlation between serum cotinine concentration and serum renalase concentration (r = -0.41, p < 0.05). Regression analysis showed that higher BMI, higher diastolic blood pressure, coronary artery disease and higher serum cotinine concentration are independent risk factors of lower serum renalase concentration. The questionnaire method of assessing exposure to tobacco smoke was characterized by high sensitivity, but only moderate specificity, especially in terms of assessing environmental exposure to tobacco smoke. In summary, the study showed an independent relationship between exposure to tobacco smoke and lower serum renalase concentration., (© 2024. The Author(s).)

Study Objectives: The International Classification of Sleep Disorders categorized catathrenia as a respiratory disorder, but there are doubts whether episodes appear during rapid eye movement (REM) sleep or the non-rapid eye movement (NREM), their duration, and symptoms. The main objectives were to identify the most common features and relations of catathrenia., Methods: PubMed, Embase, and Web of Science were searched according to the PRISMA 2020 guidelines. The Joanna Briggs Institute and the ROBINS-I tools were chosen to assess the risk of bias., Results: A total of 288 records were identified, 31 articles were included. The majority of the studies had a moderate risk of bias. 49.57% of episodes occurred during the NREM sleep, while 46% took place during REM. In 60.34% females, catathrenia was more common in the NREM, while in 59.26% of males was in REM sleep (p < 0.05). Females and obese individuals were found to have shorter episodes (p < 0.05). Age was inversely correlated with minimal episodes duration (r =  - 0.34). The continuous positive airway pressure (CPAP) therapy was inversely correlated with the maximal episode duration (r =  - 0.48)., Conclusions: Catathrenia occurs with similar frequency in both genders. The most frequent symptoms embraced groaning, awareness of disturbing bedpartners, and daytime somnolence-not confirmed by the Epworth Sleepiness Scale. The episodes occur more frequently in NREM than in REM sleep. Catathrenia may be considered as a sex-specific condition. The effects of CPAP treatment leading to shortening episodes duration, which may indicate the respiratory origin of catathrenia., (© 2024. The Author(s).)

Rhythmic masticatory muscle activity (RMMA) is a periodic muscle activity that characterises sleep bruxism (SB) events. These can occur as a single event, in pairs, or in clusters. Since RMMA episodes often occur in clusters and the relevance of this occurrence is unknown, we conducted a study to investigate the effect of RMMA clusters on sleep fragmentation and the severity of orofacial muscle pain. This study involved a secondary analysis using data from 184 adult subjects with orofacial muscle pain who underwent definitive polysomnography (PSG) for sleep bruxism diagnosis. Self-reported orofacial muscle pain (OFMP) was assessed using the numeric rating scale, and additional evaluation of side-to-side equivalence (symmetry) was described using a binary system. Among the 184 participants, 60.8% (n = 112) did not exhibit clusters and among the 72 participants with clusters, 36.1% (n = 26) and 63.9% (n = 46) were in the high and low RMMA frequency groups, respectively. The high SB group had significantly three times more phasic RMMA events than the noncluster group. A total of 89.67% (n = 165) of subjects reported orofacial muscle pain. While there was no difference in the severity of OFMP among groups, a significant decrease in symmetry between the severity of temporal muscle pain on the left and right sides was noted in the cluster group compared with the noncluster group. Clustering of RMMA events is associated with sleep fragmentation. The asymmetry of temporal muscle pain is related to the presence of RMMA clusters in sleep bruxism., (© 2023 European Sleep Research Society.)

In this comment, we explored the link between sleep fragmentation and the cardiovascular risk, considering various sleep disorders and methodologies for assessing sleep fragmentation.

Background: Sleep is a physiological function essential for survival, recovery, tissue repair, memory consolidation, and brain function. Pain is also an indispensable aspect of human life. The coexistence of sleep disorders and pain is often described in the literature, yet it is critical to define sleep not only subjectively but also using objective instrumental methods, such as polysomnography, that provide data on sleep quality., Objectives: The aim of the study was to determine the relationship between orofacial pain (OFP), headache (HA) and sleep quality using subjective and objective sleep quality assessment methods. Additionally, we aimed to explore whether poor sleep quality was related to OFP and HA alone or was influenced by the coexistence of psycho-emotional factors such as depression, anxiety and stress., Material and Methods: A single-night video-polysomnography was performed on patients from the Outpatient Clinic for Temporomandibular Disorders at Wroclaw Medical University, Poland, who had been diagnosed with OFP and HA. Additionally, questionnaires were employed to assess sleep quality, pain, HA, and the psycho-emotional state., Results: There was no statistically significant relationship between the severity of OFP and HA and polysomnographic sleep quality parameters. On the other hand, the quality of sleep as determined by questionnaire studies correlated markedly with the severity of experienced pain. The severity of pain was found to be significantly correlated with depression, anxiety and perceived stress scores., Conclusions: The psycho-emotional aspects are of critical importance in the perception of OFP and HA. They can be associated with worsened subjective sleep quality, insomnia or daytime sleepiness. Therefore, the treatment of such patients must be preceded by a comprehensive assessment of their psychoemotional state, as anxiety, stress and depression can significantly influence the course of the disease and the response to treatment procedures.

Background: Tension-type headache (TTH) is the most common primary headache. Obstructive sleep apnea (OSA) and sleep bruxism (SB) are two of the most common sleep disorders; however, the relationship between TTH, OSA, and SB has not been conclusively proved in the literature. The objective of our study was to estimate potential associations with OSA and SB in TTH subjects. Methods : 108 adult individuals who underwent polysomnography (vPSG) were included, and the group was divided into two subgroups: TTH ( n = 34) and control ( n = 74). The International Classification of Headache Disorders (ICHD-3) guidelines were used to diagnose TTH. OSA and SB diagnoses were based on vPSG examination with electromyographic (EMG) recordings and the American Academy of Sleep Medicine (AASM) criteria. The results were analyzed, where p < 0.05 was considered to be statistically significant. Results : In the TTH group, the incidence of SB was more than two times lower than the control (OR = 0.41, 95% CI: 0.17-0.96, p < 0.05). However, the incidence of severe SB (BEI > 4) was similar in the TTH and control groups (OR = 0.54, 95% CI: 0.21-1.35, p > 0.05). Additionally, phasic and tonic SB episodes were less frequent in the TTH group compared to the controls ( p < 0.05). The mean apnea-hypopnea index (AHI) was not significantly different between the TTH and control groups ( p > 0.05). The sleep architecture and respiratory disturbances did not differ between the examined groups ( p > 0.05). Conclusions : SB is not a risk factor for TTH. Moreover, severe SB is not connected with TTH. OSA is not a risk factor for TTH. Sleep quality did not differ between both groups during PSG; therefore, TTH may not change sleep structure. The mechanism of these findings is still unclear, and further studies should explain in detail the association between TTH and OSA.

Introduction: Comorbid insomnia and obstructive sleep apnea (COMISA) is not a well-identified sleep disorder, despite having a significant impact on health. This study investigates the relationship between sleep bruxism (SB) and sleep architecture in patients with COMISA, obstructive sleep apnea (OSA), and in those without any sleep disorders. Methods : 119 patients were included in the study and divided into three groups: OSA, COMISA, and a control group. Polysomnographic (PSG) examination provided parameters related to sleep architecture, OSA, and characteristics of SB. Results : The bruxism episode index (BEI) and other SB parameters were not found to be statistically different between the three groups ( p > 0.05). There was no statistical difference in measured sleep architecture between the COMISA and OSA groups ( p > 0.05). In comparison to the control group, participants in the COMISA group were found to have an increased apnea-hypopnea index (AHI), oxygen desaturation index (ODI), respiratory disturbance index (RDI), all arousals (AA), and respiratory arousals (RA) ( p < 0.05). Among COMISA patients, AA and RA were shown to have a positive linear correlation with the number of bradycardia events per hour (r = 0.49, r = 0.48, p < 0.05). Conclusions : SB does not occur in patients with COMISA more frequently than in patients with OSA or those without any sleep disorders. PSG parameters are not specific for COMISA; therefore, in order to differentiate this disorder from OSA alone, a comprehensive patient assessment has to be performed.

The aim of the study was to assess the relationship between the presence of atherosclerotic lesions in the carotid arteries detected by ultrasound and the occurrence of atherosclerosis in the coronary arteries determined by computed tomography (CT) in patients with arterial hypertension (HTA). A total of 83 patients with HTA were qualified for the study (age: 71.3 ± 8.5 years). All subjects underwent carotid arteries ultrasound and coronary arteries CT. The carotid plaque score was assessed using ultrasound. The studied group was divided into two subgroups: a subgroup with the carotid plaque score ≤ 1 (A) and a subgroup with carotid plaque score ≥2 (B). Coronary arteries CT assessed coronary artery calcium score (CACS) and degree of coronary stenosis based on CAD-RADS. In subgroup B, a significantly higher CACS (411.3 ± 70.1 vs. 93.5 ± 31.8) and significantly higher grade in the CAD-RADS classification were demonstrated than in subgroup A (CAD-RADS ≥ 3: 21.8 vs. 6.0%). The regression analysis showed that carotid plaque score and age are independent risk factors for the severity of atherosclerotic lesions in the coronary arteries. In summary, ultrasound assessment of the carotid plaque score in patients with HTA could be considered as surrogate indicator of the risk and severity of atherosclerotic changes in the coronary arteries, but further studies are necessary to corroborate these results.

Introduction: Causal relationships between psychopathological symptoms, personality traits, coping mechanisms, and sleep bruxism (SB) were studied in the past, giving inconsistent results mostly based on self-assessment evaluations. This polysomnography-based cross-sectional study aimed to explore the relationships between severe SB, personality traits (according to the Big Five model), and coping strategies with objective polysomnographic verification., Methodology: The study included 66 participants divided into severe SB (SSB) (n=32) and no or mild SB (n=34) groups based on video-polysomnography performed in the sleep laboratory. Questionnaire assessment included the use of the Beck Depression Inventory, Beck Anxiety Inventory, Mini-COPE, International Personality Item Pool Big Five Markers 20-Item version, and Oral Behavior Checklist., Results: Participants with SSB presented with fewer self-reported anxiety (p=0.008) and depressive (p=0.01) symptoms than the non- or mild-SB groups. The SSB group scored significantly higher in Big Five personal traits such as extraversion (p=0.007), emotional stability (p=0.013), and intellect (p=0.004), while regarding coping strategies, the SSB group was less likely to use negative strategies: self-distraction (p=0.036), denial (p=0.006), venting (p=0.03), behavioral disengagement (p=0.046), and self-blame (p=0.003), and turning to religion (p=0.041). The intensity of oral parafunctional behaviors was comparable in both groups (p=0.054). Emotional stability was a moderate protective factor (p=0.004), and the self-blame strategy was a strong risk factor (p<0.001) for increased oral parafunctional behavior intensity. Phasic activity negatively correlated with anxiety symptom severity (p=0.005), whereas tonic (p=0.122) and mixed (p=0.053) phenotypes did not. SB intensity was a protective factor against anxiety symptoms (p=0.016)., Conclusion: In terms of psychopathology, severe sleep bruxers tend to present less severe anxiety and depressive symptoms, while some of their personality traits (extraversion, emotional stability, and intellect) were more strongly pronounced. SSB is possibly related to the lesser use of the "maladaptive" coping strategies and there were no specific coping strategies preferred by SSB participants, compared to the other group. These observations require further studies, as it should be determined whether SB (especially phasic activity) might be a form of a somatization/functional disorder. Further research should focus on the psychogenic background of oral parafunctional behaviors, which occur more often in less emotionally stable personalities and in people using self-blame coping strategies., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision., (Copyright © 2024 Wieczorek, Jodkowska, Orzeszek, Wieckiewicz, Michalek-Zrabkowska, Mazur, Rymaszewska, Smardz, Wojakowska and Martynowicz.)

This commentary on sleep medicine explores whether the potential relationship between sleep bruxism (SB), masticatory muscle pain (MMP) and sleep breathing disorders (SBDs)contributes to improving the management of co-occurring conditions.The paper is divided into 2 sections: (1) reviewing the debate on SB nosology; and (2) based on the publications from the Martynowicz & Wieckiewicz research group, exploringthe role of intermittent hypoxia as a putative mechanism endotype that may link such co-occurrence among individuals for whom characteristics are not yet clear.

Purpose: The aim of this study was to investigate the relationship between selenoprotein P, peroxiredoxin-5, renalase, total antioxidant status (TAS), mean blood pressure (mBP), and apnea-hypopnea index (AHI)., Methods: The study group consisted of 112 patients hospitalized to verify the diagnosis of obstructive sleep apnea (OSA). The inclusion criteria were consent to participate in the study and age ≥ 18 years. Patients with active proliferative disease, severe systemic diseases, or mental diseases were excluded from the study. Each patient underwent full polysomnography and had blood pressure measured. Blood samples were collected and laboratory test was performed., Results: Among 112 patients enrolled, there was a statistically significant negative linear correlation between blood pressure values (sBP, dBP, mBP) and selenoprotein P, renalase, and TAS levels. Similarly, there was a negative linear correlation between AHI and selenoprotein P, renalase, and TAS levels, but none between AHI and peroxiredoxin-5. Based on the obtained regression models, higher selenoprotein P, peroxiredoxin-5, and renalase levels were independently associated with higher TAS. Lower mBP values were independently associated with the use of antihypertensive drugs, higher TAS, and younger age. Male gender, higher BMI, and higher mBP were independently associated with higher AHI., Conclusions: Higher concentrations of selenoprotein P, peroxiredoxin-5, and renalase were associated with higher TAS, which confirms their antioxidant properties. There was an indirect connection between tested antioxidants and blood pressure values., (© 2023. The Author(s).)

Sleep-related rhythmic movement disorder is characterised by stereotyped and repetitive rhythmic movements involving large muscle groups during sleep with frequencies between 0.5 and 2 Hz. Most of the published studies on sleep-related rhythmic movement disorder have focussed on children. Therefore, we performed a systematic review on this topic focussing on the adult population. The review is followed by a case report. The review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 guidelines. A total of seven manuscripts (n = 32 individuals) were included in the review. The clinical manifestation of body or head rolling predominated in the majority of included cases (53.13% and 43.75%, respectively). In n = 11 (34.37%) cases, a combination of rhythmic movements was observed. The literature review also revealed a wide spectrum of co-morbidities: insomnia, restless leg syndrome, obstructive sleep apnea, ischaemic stroke, epilepsy, hypertension, alcohol and drug dependency, mild depression, and diabetes mellitus. The case report presented a 33-year-old female who was referred to the sleep laboratory due to a suspicion of sleep bruxism and obstructive sleep apnea. Although the patient was initially suspected of having obstructive sleep apnea and sleep bruxism, after conducting video-polysomnography she met the criteria for sleep-related rhythmic movement disorder as she presented body rolling, which were surprisingly most evident during the rapid eye movement sleep stage. In summary, the prevalence of sleep-related rhythmic movement disorder among adults has not been determined yet. The present review and case report is a good starting point for discussion regarding rhythmic movement disorder in adults and further research on this topic., (© 2023 European Sleep Research Society.)

Obstructive sleep apnea (OSA) is one of the most common sleep disorders; however, there are inconsistent results about the connection and occurrence of primary and secondary headaches in OSA. Therefore, the primary objectives were to estimate the prevalence and potential relationship between all types of headaches and OSA. A systematic review was conducted according to PRISMA 2020 guidelines. Studies were searched in PubMed, Embase, and Web of science up to July 2023. The Joanna Briggs Institute tool assessed the risk of bias. 1845 articles were identified, and 23 studies describing 15,402 patients were included. Pooled prevalence of all headaches in OSA was 33% (95% CI: 0.25-0.41), 33% for morning headaches (95% CI: 0.24-0.45), 25% for sleep apnea headaches (95% CI: 0.18-0.34), 19% for tension-type headache (95% CI: 0.15-0.23), and 16% for migraine (95% CI: 0.09-0.26). Relative risk for the occurrence of headache in OSA patients compared to the non-OSA people was 1.43 (95% CI: 0.92-2.25). OSA females and males had morning headaches with similar frequency. The prevalence of headaches in OSA was moderate. OSA did not increase the risk of headache. There is a need to conduct further studies focused on bidirectional connections between sleep disorders and headaches., Competing Interests: Declaration of competing interest All authors declare that they have no conflict of interest., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Background: Sleep bruxism (SB) is a common sleep-related movement behavior with a multifaceted etiology and a deficiently understood pathophysiology. A recent hypothesis suggests a link between SB and systemic inflammation. The scope of the study was to determine whether bruxers have altered sleep structure and different levels of inflammatory parameters compared to nonbruxers. Methods: A total of 83 adults underwent full-night polysomnography. The polysomnograms were evaluated using the American Academy of Sleep Medicine (AASM) guidelines. Then, the blood samples were obtained from the participants by venipuncture and the analyses were performed. The study group was divided based on bruxism episode index (BEI) into two groups: BEI ≤ 4 and BEI > 4. Results: In comparison with nonbruxers, the oxygen desaturation index (ODI) was significantly higher in severe bruxers (7.5 ± 11.08 vs. 3.33 ± 5.75, p < 0.005), as well as the arousal parameters (7.77 ± 4.68 vs. 4.03 ± 2.97, p < 0.001), and the mean oxygen desaturation (3.49 ± 0.69 vs. 3.01 ± 0.67, p < 0.05). Moreover, the differences in sleep architecture and deprivation of the deep sleep phase were observed, the non-REM sleep stage 3 was significantly shorter in severe bruxers ( p < 0.03). Differences were also noted in non-REM sleep stage 1 and REM sleep phase. In the investigated group, there were no statistical differences in inflammatory cytokines levels between bruxers and nonbruxers. Conclusions: Sleep bruxism is associated with sleep structure alterations and may be associated with deep sleep phase deprivation. The inflammatory markers are not linearly correlated with the severity of sleep bruxism expressed as BEI.

Background: Obstructive sleep apnea (OSA) and arterial hypertension (AH) are closely linked disorders with common pathophysiological features., Objectives: The present study aimed to investigate the relationship between AH and OSA by examining sleep architecture, vitamin D concentration and electrolyte levels in patients with these coexisting conditions., Material and Methods: A total of 133 patients suspected of having OSA were recruited for examination. The participants were divided into 2 groups: hypertensives (n = 52); and normotensives (n = 81). One full-night polysomnographic examinations were conducted, followed by the statistical analysis of the collected data., Results: Hypertensive individuals displayed increased apnea-hypopnea index (AHI), oxygen desaturation index (ODI), respiratory arousal index (RAI), and periodic limb movement index (PLMI) as compared to non-hypertensive individuals. Moreover, sleep efficiency (SE), the bruxism arousal index (BAI) and oxygen saturation (SpO2) level were decreased in the hypertensive group. In terms of biochemical parameters, hypertensive individuals exhibited a lower magnesium (Mg) level, and higher levels of C-reactive protein (CRP), uric acid (UA) and glucose. Notably, there were no statistical differences in vitamin D concentration between hypertensive and normotensive individuals., Conclusions: The study explored the potential influence of calcium (Ca), Mg, vitamin D, and UA concentrations on the sleep architecture of patients with comorbid AH and OSA. The findings revealed several notable associations. Firstly, sleep fragmentation correlated with Ca level, suggesting a potential role for both Ca and vitamin D in sleep arousals. Secondly, a higher UA concentration was linked to a higher AHI and increased sleep fragmentation. Additionally, alterations in Mg concentration were observed among hypertensive individuals with OSA. However, further research is needed to fully comprehend the potential impact of these factors on the sleep architecture of hypertensive individuals with apnea.

Cardiovascular diseases (CVDs) are one of the biggest health challenges facing health systems around the world. There are certain risk factors (CVRFs) that contribute to CVD. Risk factors associated with lifestyle such as tobacco consumption are particularly essential. Renalase is a recently discovered flavoprotein that may be involved in the progression of cardiometabolic diseases. The aim of the study was to investigate the relation between CVRFs and blood renalase concentration (BRC). The study group consisted of 96 people (51% women) who were hospitalized in the internal medicine department. CVRFs were measured using the AHA Life 7 scale. The E3109Hu ELISA kit was used to assess BRC. We found higher BRC in groups with a lower number of CVRFs ( p < 0.05). We found a negative correlation between BRC and the number of CVRFs (r = -0.41). With the regression analysis, obesity, smoking, and a lack of physical activity (LoPE) were independently associated with lower blood renalase concentration. ROC analysis indicated the highest accuracy of BRC < 38.98 ng/mL in patients with ≥5 CVRFs. In conclusion, patients with a higher number of CVRFs had lower BRCs. The CVRFs particularly associated with a lower BRC were obesity, smoking, and LoPE.

Due to potential issues, several sleep laboratories conduct sleep bruxism diagnosis without the use of a camera, instead relying mostly on electromyographic monitoring. The purpose of the study was to determine if a camera is necessary for the polysomnographic evaluation of sleep bruxism and how sleep bruxism parameters change when a camera is not utilised. The study material was actual polysomnographic recordings made in the years 2017-2020. A total of 199 single-night video-polysomnographic recordings of patients who were suspected of having sleep bruxism were chosen at random. The first analysis involved the evaluation of the video recording, while in the second video recording was not used. The findings revealed that all the examined sleep bruxism indices had statistically significantly higher values for the recordings made without the use of a camera. According to the findings, noncamera recordings had decreased sensitivity and specificity when the criteria of bruxism and mild-to-moderate bruxism were taken into account, and decreased sensitivity in the case of the criterion of severe bruxism. Sleep efficiency, the apnea/hypopnea index, and arousals had independent effects on the bruxism episode index value in the analysis of noncamera recordings. In conclusion, camera-based polysomnography still appears to be the most reliable way to assess the severity of sleep bruxism, particularly in patients who also report other sleep disturbances. The presence of symptoms of sleep-disordered breathing, insomnia, or other sleep disorders should prompt us to use camera-based diagnostics., (© 2023 European Sleep Research Society.)

Sleep research has garnered substantial interest among scientists owing to its correlation with various diseases, particularly elevated blood pressure observed in patients with obstructive sleep apnea. This systematic review aims to identify and analyze publications exploring the associations between sleep architecture and arterial hypertension. A comprehensive search of PubMed (MEDLINE), Scopus, and Embase databases yielded 111 reports, of which 7 manuscripts were included in the review. Four of the studies reported a significant reduction in the duration of the N3 phase of sleep in hypertensive patients, while 2 studies found a statistically significant reduction in the duration of the N2 and rapid eye movement (REM) stages of sleep. Three studies indicated increased sleep fragmentation in hypertensive patients. They showed a longer duration of the N1 stage of sleep, shorter duration of overall sleep time, and an increased apnea-hypopnea index in hypertensive patients. These findings underscore the association between the duration of non-REM/REM sleep stages and elevated BP, providing substantial evidence. Moreover, a notable increase in sleep fragmentation was observed among patients with hypertension. However, further research is warranted to expand and deepen our understanding of this intricate relationship. This systematic review serves as a valuable resource, guiding future investigations and contributing to advancements in the field of sleep and arterial hypertension.

Obstructive sleep apnea (OSA) is a risk factor for cardiovascular disease, inflammation, and oxidative stress. This study compared serum levels of different factors in patients with carotid artery stenosis and with or without coexisting OSA. It also aimed to identify a molecule that may be crucial for the inflammatory process correlated with intermittent hypoxia. Sixty-eight subjects scheduled for surgical treatment of carotid artery stenosis were enrolled. Polygraphy was performed the night before the surgery. Morning levels of proinflammatory cytokines and chemotactic and angiogenic factors were measured. The most profound differences between the groups were found for ENA-78 serum concentration. However, as many factors could affect the results, further studies are needed to investigate the role of ENA-78 in atherosclerosis in patients suffering from OSA., Competing Interests: Conflicts of interest Authors declared no conflict of interests., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Sleep bruxism (SB) is a sleep-related behavior characterized as rhythmic (phasic) or non-rhythmic (tonic) masticatory muscle activity. SB is a common sleep behavior with a predominantly central origin. The aim of this systematic review was to evaluate the relationship between inflammatory status and SB according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 (PRISMA 2020). The research was registered at PROSPERO (CRD42023395985). We performed a systematic literature analysis using five different databases. Furthermore, the backward snowballing technique was applied to identify additional papers. Initially, 28 papers were screened from the database search, and 162 papers were revealed in the backward snowballing process. Eventually, five articles were included. Data concerning the inflammatory status of patients experiencing SB were investigated and summarized. Due to the heterogeneity of the compared studies, only a qualitative comparison and narrative summary were performed. The results suggest that SB could be associated with systemic inflammation. In fact, this systematic review revealed that there are no papers conclusively showing that the inflammatory status in bruxers is comparable to non-bruxers. However, each of the examined studies utilized different methods of assessing systemic inflammation, which makes the results dubious.

This exploratory observational study aimed to evaluate whether the blood levels of serotonin and enzymes involved in serotonin synthesis are associated with sleep breathing parameters. A total of 105 patients were included in this study, who were subjected to single-night polysomnography with simultaneous audio-video recordings. Peripheral blood samples were collected to estimate the serum levels of serotonin, tryptophan hydroxylase 1 (TPH1), and aromatic l-amino acid decarboxylase (AADC). Results showed a negative correlation between blood serotonin levels, and oxygen desaturation index (ODI) (p = 0.027), central apnea (p = 0.044) and obstructive apnea (OA) (p = 0.032) scores. Blood TPH1 levels were negatively correlated with average (p = 0.003) and minimal saturation (p = 0.035) and positively correlated with apnea-hypopnea index (p = 0.010), OA (p = 0.049), and hypopnea index (p = 0.007) scores. A tendency to sleep-disordered breathing seemed to co-occur with lower blood serotonin and higher TPH1 levels.Clinical Trial Registration : www.ClinicalTrials.gov , identifier NCT04214561., (© 2023. The Author(s).)

Obstructive sleep apnea is considered a risk factor for erectile dysfunction. The aim of this study was to determine sleep architecture and assess daytime sleepiness in patients with erectile dysfunction. The study group included 280 patients. The 107 enrolled patients had reported erectile dysfunction. The control group consisted of 173 patients who had no history of erectile dysfunction. The Epworth sleepiness scale (ESS) was used to measure the subjects' level of daytime sleepiness. All patients underwent a standardized overnight, single-night polysomnography in sleep laboratory. In the erectile dysfunction group, we observed increased ESS total score and N1 sleep phase duration. Mean and minimal oxygen saturation and mean oxygen desaturation were decreased in comparison to the control group. In summary, subjects with erectile dysfunction have altered sleep architecture, oxygen saturation parameters and increased daytime sleepiness.

Cadmium is a heavy metal that accumulates in the body due to environmental and occupational exposure. The main form of environmental exposure to cadmium is related to cigarette smoking. The primary aim of this study was to evaluate the effect of cadmium on numerous sleep parameters with the use of polysomnography. The secondary aim of this study was to investigate if environmental exposure to cadmium is a risk factor for the intensity of sleep bruxism (SB)., Methods: A total of 44 adults underwent a full night of polysomnographic examination. The polysomnograms were assessed according to guidelines set out by the American Academy of Sleep Medicine (AASM). The concentration of cadmium in the blood and urine was determined spectrophotometrically., Results: The polysomnographic examination confirmed that cadmium, age, male gender and smoking status are independent risk factors for an increase in the apnea-hypopnea index (AHI). Cadmium alters sleep architecture by favoring sleep fragmentation and decreasing the duration of the rapid eye movement (REM) phase of sleep. However, cadmium exposure is not a risk factor for the development of sleep bruxism., Conclusions: In summary, this study demonstrates that cadmium affects sleep architecture and is a risk factor for the development of obstructive sleep apnea; however, it does not affect sleep bruxism.

This study aimed to assess the relationship between chosen antioxidants, namely selenoprotein P (SELENOP), peroxiredoxin-5 (Prdx-5), renalase and selected cardiovascular consequences tested in ambulatory blood pressure monitoring (ABPM) and echocardiography (ECHO). In our work, cardiovascular consequences refer to higher mean blood pressure (MBP) and pulse pressure (PP) on ABPM, as well as to left atrial enlargement (LAE), left ventricular hypertrophy (LVH) and lower left ventricular ejection fraction (LVEF%) on ECHO. The study group consisted of 101 consecutive patients admitted to the Department of Internal Medicine, Occupational Diseases and Hypertension to verify the diagnosis of Obstructive Sleep Apnoea (OSA). Each patient underwent full polysomnography, blood tests, ABPM and ECHO. Both selenoprotein-P and renalase levels correlated with different ABPM and ECHO parameters. We found no correlation between the peroxiredoxin-5 level and none of the tested parameters. We point to the possible application of SELENOP plasma-level testing in the initial selection of high cardiovascular-risk patients, especially if access to more advanced examinations is limited. We further suggest SELENOP measurement as a possible indicator of patients at increased left ventricular hypertrophy risk who should be of particular interest and may benefit from ECHO testing.

Background: Sleep bruxism (SB) is a common behavior that can result in various clinical consequences on human health. Risk factors for SB include among others emotional stress, anxiety, tobacco smoking, and excessive alcohol consumption. Coffee and black tea are among the most commonly consumed beverages worldwide. This study explores the influence of coffee and black tea consumption on bruxism intensity, as observed in polysomnographic examination., Methods: Polysomnographic examination with simultaneous camera recording was conducted in 106 adult subjects. The results were evaluated according to guidelines set out by the American Academy of Sleep Medicine (AASM). The study group was divided according to habitual stimulant usage, as declared by the participants in a self-reported questionnaire. Four groups were identified: coffee drinkers versus non-drinkers and black tea drinkers versus non-drinkers., Results: The bruxism episode index (BEI) was increased in coffee-drinkers as opposed to non-drinkers (4.59 ± 3.44 vs. 2.87 ± 1.50, p = 0.011). Sleep fragmentation, measured according to the arousal index, was comparable in coffee drinkers and non-drinkers. Electrolyte and lipid levels were similar in coffee drinkers and non-drinkers. Habitual black tea intake did not affect sleep architecture or bruxism intensity., Conclusions: The study showed that habitual coffee consumption is a risk factor for the increased intensity of sleep bruxism. Neither coffee nor tea consumption is related to sleep fragmentation in habitual drinkers. Coffee and tea intake does not affect electrolyte and lipid concentrations. Caution should therefore be recommended in drinking coffee in people with sleep bruxism., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2023 The Authors.)

Obesity and sarcopenia, i.e., decreased skeletal muscle mass and function, are global health challenges. Moreover, people with obesity and sedentary lifestyles often have sleep disorders. Despite the potential associations, metabolic disturbances linking obesity, sarcopenia, and sleep disorders with cancer are neither well-defined nor understood fully. Abnormal levels of adipokines and adipomyokines originating from both adipose tissue and skeletal muscles are observed in some patients with obesity, sarcopenia and sleep disorders, as well as in cancer patients. This warrants investigation with respect to carcinogenesis. Adipokines and adipomyokines may exert either pro-carcinogenic or anti-carcinogenic effects. These factors, acting independently or together, may significantly modulate the incidence and progression of cancer. This review indicates that one of the possible pathways influencing the development of cancer may be the mutual relationship between obesity and/or sarcopenia, sleep quantity and quality, and adipokines/adipomyokines excretion. Taking into account the high proportion of persons with obesity and sedentary lifestyles, as well as the associations of these conditions with sleep disturbances, more attention should be paid to the individual and combined effects on cancer pathophysiology.

The aim of this study was to assess the coronary artery calcium score in patients with obstructive sleep apnea (OSA). The study group (group A) consisted of 62 patients with diagnosed obstructive sleep apnea (mean age: 59.12 ± 9.09 years, mean AHI index in polysomnography: 20.44 ± 13.22/h), and 62 people without diagnosed obstructive sleep apnea (mean age 59.50 ± 10.74 years) constituted the control group (group B). The risk of significant coronary artery disease was assessed in all patients, based on the measurement of the coronary artery calcium score (CACS) using computed tomography. The following cut-off points were used to assess the risk of significant coronary artery disease: CACS = 0-no risk, CACS 1-10-minimal risk, CACS 11-100-low risk, CACS 101-400-moderate risk, and CACS > 400-high risk. Group A was characterized by statistically significantly higher CACS than group B (550.25 ± 817.76 vs. 92.59 ± 164.56, p < 0.05). No risk of significant coronary artery disease was statistically significantly less frequent in group A than in group B (0.0% vs. 51.6%, p < 0.05). A high risk of significant coronary artery disease was statistically significantly more frequent in group A than in group B (40.3% vs. 4.8%, p < 0.05). In group A, patients with severe OSA and patients with moderate OSA had statistically significantly higher CACS than patients with mild OSA (910.04 ± 746.31, 833.35 ± 1129.87, 201.66 ± 192.04, p < 0.05). A statistically significant positive correlation was found between the AHI and CACS (r = 0.34, p < 0.05). The regression analysis showed that OSA, male gender, older age, type 2 diabetes, peripheral arterial disease, and smoking were independent risk factors for higher CACS values. AHI ≥ 14.9 was shown to be a predictor of a high risk of significant coronary artery disease with a sensitivity and specificity of 62.2% and 80.0%, respectively. In summary, obstructive sleep apnea should be considered an independent predictive factor of a high risk of significant coronary artery disease (based on the coronary artery calcium score).

Background/aim: Asymmetric dimethylarginine (ADMA) is an endogenous inhibitor of nitric oxide (NO) production and a newly discovered risk factor involved in endothelial dysfunction and adverse cardiovascular events. Recently, both NO and ADMA have also emerged as molecules of interest in carcinogenesis and tumor growth progression. Our earlier studies have confirmed elevated plasma ADMA levels in patients with hematological malignancies. However, the cause of elevated ADMA was unclear. The aim of this study was to assess the concentrations of ADMA, symmetric dimethylarginine (SDMA) and L-arginine in rats exposed to N-nitroso-N-methylurea (NMU) for the induction of mammary tumors., Materials and Methods: A total of 95 female rats of the Sprague-Dawley strain were used in the study. Plasma concentrations of ADMA, SDMA and L-arginine were quantified and statistically analyzed., Results: Mean ADMA levels were higher in the tumor-bearing group compared to the control group. Mean plasma levels of SDMA and L-Arginine were not significantly different between the groups. The L-ARG/ADMA ratio was lower in rats with tumors compared to controls., Conclusion: Histological assessment confirmed expression of ADMA within the tumor cells, which strongly suggests that these tumor cells were the source of ADMA. Other studies are warranted to further explain the role of ADMA in neoplastic diseases., (Copyright © 2023 International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Background: Sleep bruxism (SB) is a common sleep-related movement behavior with a complex etiology. A recent hypothesis suggests psychoactive substance usage, tobacco smoking, and alcohol intake are risk factors for SB. This study aimed to evaluate SB intensity in tobacco smokers and alcohol drinkers. Methods: A total of 133 adults underwent full-night audio- and video-polysomnography, and the polysomnograms were evaluated using the American Academy of Sleep Medicine guidelines. The study group was divided into smoker and nonsmoker groups as well as drinker and non-drinker groups. Results: The results of the polysomnographic analysis confirmed that tobacco smoking has a significant effects on SB. Tobacco smokers showed increased bruxism intensity (5.50 ± 4.71 vs. 3.83 ± 3.26, p < 0.05), especially the mixed phenotype (0.93 ± 1.00 vs. 0.59 ± 0.59, p < 0.05), in the N1 sleep stage (22.84 ± 20.45 vs. 15.66 ± 13.60, p < 0.05) and the nonsupine position (4.93 ± 5.56 vs. 2.50 ± 2.31, p < 0.05). They also showed a higher number of bruxism episodes with arousal compared with nonsmokers (2.91 ± 2.83 vs. 1.61 ± 1.49, p < 0.05), indicating increased sleep fragmentation. However, no significant effect of alcohol on SB intensity was observed, and the bruxism episode index was similar in alcohol drinkers and nondrinkers. In addition, electrolyte disturbances and lipid disorders were evaluated. Compared with nonsmokers, tobacco smokers showed a higher concentration of plasma triglycerides (177.67 ± 106.9 vs. 129.18 ± 65.61) and lower levels of iron and magnesium (96.68 ± 43.58 vs. 123.83 ± 52.36 and 1.85 ± 0.22 vs. 1.96 ± 0.21, respectively). Conclusions: In summary, this study showed that tobacco smoking, but not alcohol consumption, is related to bruxism intensity and lipid and electrolyte disturbances in individuals with sleep disorders.

Introduction: Endothelial dysfunction resulting from decreased nitric oxide (NO) bioavailability is an important mechanism that increases cardiovascular risk in subjects with obstructive sleep apnea (OSA). NO is produced by nitric oxide synthase (NOS) in a reaction that converts L-arginine to L-citrulline. Asymmetric-dimethylarginine (ADMA) is created by L-arginine and is a naturally occurring competitive inhibitor of nitric oxide synthase (NOS). The aim of our study was to verify if erythrocytes could play a role in the storage and accumulation of ADMA in OSA patients. The crosstalk between erythrocyte-ADMA, SDMA, L-arginine, and L-citrulline levels and endothelial function was investigated in OSA subjects both at baseline and prospectively following 1-year CPAP (continuous positive airway pressure) treatment., Material and Methods: A total of 46 subjects with OSA were enrolled in this study and divided into two groups: those with moderate-to-severe OSA and those with mild or no OSA. A physical examination was followed by blood collection for the assessment of biochemical cardiovascular risk factors and the nitric oxide bioavailability parameters both in plasma and erythrocytes. Vasodilative endothelial function was assessed using Laser Doppler Flowmetry (LDF)., Results: No significant changes regarding the NO pathway metabolites were noted apart from the plasma L-citrulline concentration, which was decreased in patients with OSA (26.9 ± 7.4 vs. 33.1 ± 9.4 μM, p < 0.05). The erythrocyte ADMA concentration was lower than in plasma irrespective of the presence of OSA (0.33 ± 0.12 vs. 0.45 ± 0.08 μM in OSA, p < 0.05 and 0.33 ± 0.1 vs. 0.45 ± 0.07 μM in the control, p < 0.05). No significant changes regarding the LDF were found. CPAP treatment did not change the levels of NO metabolites in the erythrocytes., Conclusions: The erythrocyte pool of the NO metabolic pathway intermediates does not depend on OSA and its treatment, whereas the erythrocytes could constitute a high-volume buffer in their storage Hence, the results from this prospective study are a step forward in understanding the role of the erythrocyte compartment and the intra-erythrocyte pathways regulating NO bioavailability and paracrine endothelial function in the hypoxia-reoxygenation setting, such as obstructive sleep apnea.

Plasma sodium plays a major role in regulating blood pressure (BP). An augmented variability of BP is considered a risk factor for the development of arterial hypertension, which is prevalent among patients with suspected sleep bruxism (SB). The aims of this study were to assess the plasma concentration of electrolytes and their effect on the intensity of SB and BP variability among sleep bruxers. A total of 51 patients were enrolled in this prospective, observational study. A single full-night polysomnographic examination was conducted in the Wroclaw Medical University Sleep Laboratory, Poland, and based on the guidelines of the American Academy of Sleep Medicine, the results were analyzed. The monitoring of ambulatory BP was performed the next day, and the plasma levels of sodium, potassium, magnesium, and calcium were measured. The mean age of the studied group was 33.9 ± 11.2 years, and the mean bruxism episode index (BEI) was 4.94 ± 3.53. The study revealed statistically significant differences in the plasma concentrations of sodium in the SB group. A decreased sodium concentration was observed in the group of mild bruxers (2 ≤ BEI < 4) (139.7 ± 1.4 vs. 142.8 ± 3.2, p = 0.002) and severe bruxers (BEI ≥ 4) (140.5 ± 2.0 vs. 142.8 ± 3.2, p = 0.016) compared to nonbruxers (BEI < 2). A statistically significant positive linear correlation was found between plasma sodium concentration and daytime systolic BP variability (r = 0.32, p < 0.05) as well as between plasma sodium concentration and nighttime diastolic BP variability (r = 0.31, p < 0.05). The preliminary results suggest the probable relationship between the lower plasma concentration of sodium and increased intensity of SB and BP variability among suspected sleep bruxers.

Introduction: Obstructive sleep apnea (OSA) is a worldwide breathing disorder that has been diagnosed globally in almost 1 billion individuals aged 30−69 years. It is characterized by repeated upper airway collapses during sleep. Telomerase reverse transcriptase (TERT) is involved in the prevention of telomere shortening. This prospective, observational study aimed to investigate the relationship between single nucleotide polymorphisms (SNPs) of TERT and the severity of OSA, taking into account hypertension and diabetes prevalence. Methods: A total of 149 patients with OSA were diagnosed using one-night video-polysomnography based on the American Academy of Sleep Medicine guidelines. The TERT SNPs and telomere length (TL) were detected using real-time quantitative polymerase chain reaction. Results: Statistical analysis showed that there is no relationship between the rs2853669 and rs2736100 polymorphisms of TERT, and the severity of OSA (p > 0.05). Moreover, no relationship between TL and the severity of OSA was observed. The G allele in the locus of rs2736100 TERT was associated with hypertension prevalence and was more prevalent in hypertensives patients (46.00% vs. 24.49%, p = 0.011). The prevalence of hypertension was higher in patients with the C allele in the locus of rs2853669 than in patients without this allele (50.79% vs. 30.23%, p = 0.010). Moreover, a lower prevalence of diabetes was observed in homozygotes of rs2736100 TERT than in heterozygotes (5.63% vs. 15.38%, p = 0.039). Conclusion: This study showed no relationship between OSA and TERT SNPs. However, SNPs of the TERT gene (rs2736100 and rs2853669) were found to affect arterial hypertension and diabetes prevalence.

Background: Jaw motor activity (MA) in sleep bruxism (SB) has been demonstrated to accompany lower limb movements. However, it remains unknown whether SB activity coexists with other types of movements and what the possible underlying mechanisms of such temporal coexistence are. In obstructive sleep apnea (OSA), increased movement activity is also reported, including SB activity; however, no studies have compared MA in apneic and nonapneic SB patients., Aim: This cross-sectional study focused on the phenomenon of "big body movements" in patients with either SB or OSA (or both) and intended to identify the primary factors contributing to their appearance, using polysomnography (PSG) recording., Methods: A whole-night videoPSG was carried out in 287 participants, and 124 apneic and 146 nonapneic participants were selected for the study. In both groups, participants were further divided into no SB, moderate SB, and severe SB (SSB) subgroups based on their bruxism episode index (BEI). MA was recorded using a built-in sensor of the central PSG unit located on the participant's chest during the examination., Results: The presence of SB was related to the higher intensity of MA in both apneic and nonapneic participants, though in general the MA level was higher in apneic participants, with the highest level observed in SSB apneic participants., Conclusions: SB might contribute to MA. The prevalence of SB might be higher in nonapneic patients due to phasic and mixed SB activity, whereas the SB phenotype seems to be less relevant in apneic patients. SB activity is likely to increase MA in non-REM 1 sleep.

The aim of this study was to analyze the relationship between the initiation of CPAP therapy and HRV in patients with OSA. The study group consisted of 37 patients, aged 34-79 (mean 54.95 years) with OSA treated with CPAP. Two subgroups of patients were distinguished: less than severe (AHI < 30, n  = 16) and severe OSA (AHI ≥ 30, n  = 21). The second study was carried out around a month after the initiation of therapy. CPAP therapy caused the improvement in polysomnographic parameters, however, in most parameters in time and frequency analysis, there were no significant positive changes in parasympathetic tone. Moreover, in HRV time analysis, the reduced rMSSD and pNN50 parameters in the hours of night rest and rMSSD and SDSD during the 15-min N3 sleep period were noted. Especially, in the group with AHI ≥ 30, we observed significant decreases in rMSSD and pNN50 for the entire time. The changes were mainly for the night periods including the N3 sleep period, which is especially connected with sleep apnea (parameters: rMSSD, SDSD, and pNN50). In spectral analysis, the decrease in HF from the 15-min daily activity period and the N3 sleep period was observed. Inverse correlations were seen between the maximum, median, and mean positive airway pressure (PAP) and the change in rMSSD, SDNN, and SDSD, mainly during night hours and the N3 sleep period. Only in patients with AHI < 30 the increase in SDNN was observed in 15-min N3 sleep period. The beneficial increase in SDNN parameter from time analysis was observed only in one sleep period in less ill patients with OSA. The lack of significant changes was observed in the majority of the parameters of heart rate variability after initiation of CPAP therapy in a short observational time; however, the shift towards reduced HRV was observed in patients with AHI > 30, so the response to CPAP therapy may depends on the severity of the apnea. The results may suggest that a longer observational period is needed in such studies, and the problem is still not fully elucidated., Competing Interests: Conflict of interestAll authors certify that they have no affiliations with or involvement in any organization or entity with any financial interest (such as honoraria; educational grants; participation in speakers' bureaus; membership, employment, consultancies, stock ownership, or other equity interest; and expert testimony or patent-licensing arrangements), or non-financial interest (such as personal or professional relationships, affiliations, knowledge or beliefs) in the subject matter or materials discussed in this manuscript., (© The Author(s) 2022.)

(1) Background: Sleep bruxism (SB) is a common sleep behavior. Obstructive sleep apnea (OSA) is a prevalent sleep-related breathing disorder with potential long-term major neurocognitive and cardiovascular sequelae. Although the co-occurrence of SB and OSA has been described previously, the exact relationship remains unclear. The present study aimed to evaluate the incidence of SB in different phenotypes of OSA. (2) Methods: The participants of this study were adult patients referred to the Department and Clinic of Internal Medicine, Occupational Diseases, Hypertension and Clinical Oncology at the Wroclaw Medical University. They underwent a single-night video polysomnography in a sleep laboratory. The data related to common OSA phenotypes were analyzed in two separate groups of patients: body position related (n = 94) and rapid eye movement (REM) related (n = 85). (3) Results: The obtained results showed that the incidence of SB and severe SB was higher for body position-related OSA phenotype (p < 0.05 for all comparisons). No statistically significant differences were observed for REM-related OSA phenotype (p > 0.05 for all comparisons). (4) Conclusions: Body position-related OSA phenotype seems to be associated with higher SB and severe SB incidence, but the relationship is not independent. However, in the light of the unclear relationship between SB and sleep-disordered breathing, the topic needs further study.

The aim of the study was to determine the relationship between the serum selenium concentration (Se-S) and the blood concentrations of osteoprotegerin (OPG), receptor activator of nuclear factor kappa-Β ligand (RANKL) and the OPG/RANKL ratio in patients with arterial hypertension. The study group comprised 138 patients with arterial hypertension (age: 56.04 ± 11.59 years). Se-S was determined in all the subjects. Based on the Se-S, the following subgroups were distinguished: a subgroup of patients with a lower Se-S ("low-Se", Se-S < median) and a subgroup of patients with a higher Se-S ("high-Se", Se-S ≥ median). Moreover, the blood concentrations of the parameters of bone metabolism and extraskeletal calcification were assessed: OPG and RANKL. The OPG/RANKL ratio was calculated. In the "low-Se" subgroup, the RANKL concentration was statistically significantly lower, and the OPG/RANKL ratio was statistically significantly higher than in the patients in the "high-Se" subgroup. The correlation analysis showed the negative linear relationships between Se-S and OPG (r = - 0.25, p < 0.05) and between Se-S and OPG/RANKL (r = - 0.47, p < 0.05). Moreover, Se-S positively correlated with RANKL (r = 0.33, p < 0.05). In regression analysis, higher body mass index (BMI), smoking and lower Se-S were independently associated with a higher OPG/RANKL ratio, while lower BMI, use of diuretics, β-blockers and ACE inhibitors and lower OPG/RANKL ratio with effective blood pressure control. In summary, in the group of patients with arterial hypertension, lower Se-S is associated with an unfavourable prognostic panel of parameters of bone metabolism and extraskeletal calcification. Lower Se-S is an independent risk factor for a higher OPG/RANKL ratio, which is an independent prediction factor of ineffective blood pressure control in patients with hypertension., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Obstructive sleep apnea (OSA) and sleep bruxism (SB) may appear concomitantly. Data on the relationship between OSA and SB are limited. It was shown that in a population with an increased risk of OSA, OSA was dependently correlated with SB on the degree of OSA severity only in mild and moderate cases of OSA. We aimed to confirm this relationship and affecting factors in a group of dental office patients in a prospective, observational study. Adult patients (n = 119) were evaluated using respiratory polygraphy. The risk of OSA was assessed using a STOP-Bang questionnaire (SBQ). The episodes of bruxism and respiratory events were scored according to the standards of the American Academy of Sleep Medicine. The prevalence of OSA and SB was found to be 63.02% and 41.17%, respectively. The bruxism episode index (BEI) was increased in the group with a higher risk of OSA (SBQ ≥ 3) compared to the group with a lower risk of OSA (3.49 ± 3.63 vs. 2.27 ± 2.50, p = 0.03). The sensitivity and specificity of the SBQ were not sufficient to predict SB. A positive linear correlation between AHI and BEI in the group with AHI < 23/h was found. The study confirmed that OSA was associated with SB in the group of patients with OSA and/or SB risk. The relationship between OSA and SB depended on the degree of severity of OSA and occurred in mild and moderate cases of OSA.

Sleep bruxism (SB) is a repetitive jaw muscle activity characterized by clenching or grinding of the teeth, which is classified under sleep-related movement disorders in the International Classification of Sleep Disorders-Third Edition. Because the potential common pathomechanism of SB and arterial hypertension is the activation of the sympathetic system as well as an increase in inflammatory factors, we aimed to examine the intensity of SB and the sleep architecture among patients with arterial hypertension. The study included a total of 91 Caucasian adult patients, among whom 31 had arterial hypertension diagnosed according to the current European Society of Cardiology/European Society of Hypertension (ESC/EHS) hypertension guidelines. The control group consisted of 61 normotensive patients. Patients with obstructive sleep apnea were excluded. A single full-night polysomnographic examination was conducted in the Sleep Laboratory, and then the results were analyzed based on the guidelines of the American Academy of Sleep Medicine. Bruxism episode index (BEI) was higher in the hypertensive group compared to normotensives. The groups also showed statistically significant differences in polysomnographic sleep indexes. Similar to BEI, arousal index, apnea-hypopnea index, and snoring were higher in hypertensives compared to normotensives. On the other hand, the mean and minimal oxygen saturation were lower in hypertensives compared to normotensives. A statistically significant positive correlation was observed between oxygen desaturation index and BEI in the hypertensive group, whereas this correlation was not statistically significant in the case of normotensives. In summary, nonapneic hypertensives had higher SB intensity, altered sleep architecture, decreased mean oxygen saturation, and increased snoring compared to normotensives. The results suggest that dental screening is necessary for patients with arterial hypertension, especially those presenting with the symptoms of SB.

Obstructive sleep apnea is the most common sleep-related breathing disorder. In the pandemic times of the new coronavirus SARS-CoV-2, CPAP (Continuous Positive Airway Pressure) therapy of obstructive sleep apnea became even more challenging. After the pandemic outbreak in March 2020, most CPAP treatment recommendations changed because of rising concerns about CPAP usage safety for patients and their families. Therefore, we examined the effectiveness of CPAP and adherence to the therapy of 149 adults with obstructive sleep apnea in the period of two years from 4 March 2019 to 3 March 2021 (before pandemic breakout and during the first year of pandemic). Data on CPAP parameters and adherence to therapy were obtained via a telemetric system. Together, our results demonstrated that the COVID-19 pandemic had no significant impact on CPAP therapy parameters and adherence in whole study group. However, detailed analysis acknowledged that some demographic and clinical features influenced CPAP therapy. The results showed that across subgroups of patients differentiated on the basis of age, gender, co-existing diabetes mellitus, or hypertension, the COVID-19 pandemic seemed to affect CPAP effectiveness. Our results provide a good starting point for discussion on CPAP therapy recommendations during pandemic times.

Objectives: This exploratory research aimed to evaluate the levels of tryptophan hydroxylase 1 (TPH1) and aromatic l-amino acid decarboxylase (DDC), which play an important role in the serotonin synthesis pathway, in individuals with sleep bruxism (SB) diagnosed using audio-video polysomnography (vPSG) and compare them with that of individuals not presenting with SB., Materials and Methods: The study included adult patients hospitalized in the Department and Clinic of Internal Medicine, Occupational Diseases, Hypertension and Clinical Oncology at the Wroclaw Medical University. The participants underwent a single-night vPSG for the evaluation of the SB parameters. Peripheral blood samples were also collected from them for estimating the serum levels of TPH1 and DDC., Results: A total of 105 patients (80 women and 25 men) were included in the study. All the patients were Caucasians and aged 18-63 years (mean age: 33.43 ± 10.8 years). Seventy-five patients (71.43%) presented with SB, of which 50 (47.62%) had severe SB, while the remaining 30 patients (28.57%) did not. No statistically significant differences in TPH1 and DDC levels were observed between the individuals with SB and without SB. A significant negative correlation was found between tonic SB episodes and DDC levels (p = 0.0012). Other correlations between the SB parameters and the levels of the studied enzymes were statistically insignificant (p > 0.05 for all comparisons)., Conclusions: The levels of the enzymes that are crucial for serotonin synthesis (TPH1 and DDC) did not seem to influence SB., Clinical Relevance: This study provides important insights for further research on the relationship between the serotonin pathway and SB, which should take into account not only the process of serotonin synthesis but also the effect of serotonin-dependent neurotransmission on SB., (© 2021. The Author(s).)

Background: Sleep bruxism (SB) is a complex behaviour that seems to be associated with the serotoninergic pathway., Objectives: This exploratory research aimed to evaluate the levels of serotonin in individuals with sleep bruxism diagnosed by video polysomnography. The study also evaluated whether the levels of serotonin were associated with body mass index, heart rate, and sleep parameters., Methods: The study participants were adults hospitalised in the Department and Clinic of Internal Medicine, Occupational Diseases, Hypertension and Clinical Oncology at the Wroclaw Medical University. They underwent a single-night video polysomnography during which sleep and SB parameters and heart rate were evaluated. Additionally, body mass index and blood serotonin levels were evaluated for each patient., Results: A total of 105 patients were included in this study (80 women and 25 men). All the patients were Caucasians aged 18-63 years, with a mean age ± (standard deviation) of 33.43± 10.8 years. Seventy-five patients (71.43%) presented sleep bruxism (bruxism episodes index ≥2) and 30 (28.57%) did not. Fifty patients (47.62%) presented severe sleep bruxism (bruxism episodes index >4). The results showed that lower blood serotonin levels were associated with severe sleep bruxism; increased bruxism episodes index, rapid eye movement sleep, and body mass index; and decreased maximal pulse., Conclusion: Severe sleep bruxism and the associated phenomena seem to co-occur with lower blood serotonin levels. The study supports the hypothesis on the relationship between the serotoninergic pathway and sleep bruxism., (© 2021 John Wiley & Sons Ltd.)

The purpose of this study was to determine the relationship between cadmium exposure and the likelihood of developing or exacerbating symptoms of inflammatory arthritis (IA). The study included 51 IA patients and 46 control subjects. Demographic and lifestyle data were collected. Haematological and biochemical parameters and blood cadmium levels (Cd-B) were determined. Cd-B correlated positively with age, smoking, living in a high-traffic area, and serum levels of inflammatory markers and negatively with mean corpuscular haemoglobin concentration (MCHC). The binary logistic regression model implied that high Cd-B (≥0.65 μg/L) is linked with an increased risk of IA in the studied population (odds ratio: 4.4). High levels of DNA oxidative damage marker (8-hydroxy-2'-deoxyguanosine) (≥7.66 ng/mL) and cyclooxygenase-2 (≥22.9 ng/mL) and frequent consumption of offal was also associated with increased risk of IA. High Cd-B was related to increased risk of disease symptoms onset in the group of IA patients, decreased the level of interleukin 10, and positively correlated with the disease activity. Increased Cd-B is associated with intensified inflammatory processes and decreased haemoglobin levels; in IA patients with decreased anti-inflammatory interleukin 10. These changes partly explain why cadmium exposure and a high cadmium body burden may raise the risk of IA and of disease symptoms exacerbation.

Objective : To evaluate the correlation between the Bruxism Episodes Index (BEI) that determines the number of bruxism episodes per hour of sleep and sleep quality as measured by the Pittsburgh Sleep Quality Index (PSQI). Methods : Seventy-seven participants (56 women and 21 men) in which probable sleep bruxism was diagnosed using guidelines of the American Academy of Sleep Medicine underwent video-polysomnography. Sleep quality was measured using PSQI. Results : The analysis showed the lack of a statistically significant correlation between the BEI and PSQI scores ( p = 0.55). Analysis also showed that the study group (bruxers) and control group (non-bruxers) did not differ significantly in terms of PSQI scores ( p = 0.88). Conclusion : The intensity of bruxism seems not to affect the quality of sleep. However, the topic of the relationship between sleep quality and the occurrence of sleep bruxism requires further research, taking into account co-occurring sleep disorders and sleep architecture.