Blunted tachycardia and cardiac sympathetic denervation in isolated rapid eye movement sleep behavior disorder.

BACKGROUND: Isolated rapid eye movement sleep behavior disorder (iRBD) serves as a prodromal phase of Parkinson's disease (PD) and dementia with Lewy bodies (DLB). Blunted tachycardia (BT) during postural changes indicates neurogenic orthostatic hypotension, a marker of autonomic dysfunction. We aimed to investigate whether BT is associated with cardiac sympathetic neurogenic denervation. Additionally, we conducted a preliminary short-term follow-up to examine the potential prognostic significance of BT regarding phenoconversion and mortality. METHODS: Forty-three patients with iRBD at Shiga University of Medical Science Hospital underwent active standing tests to identify BT, defined by a specific ratio of decrease in systolic blood pressure to inadequate increase in heart rate after standing, and orthostatic hypotension. 123I-metaiodobenzylguanidine myocardial scintigraphy (123I-MIBG) and dopamine transporter single-photon emission computed tomography (DAT-SPECT) were performed. Participants were followed up for 3.4 ± 2.4 years for phenoconversion and 4.0 ± 2.3 years for mortality assessment, and the risk of events was analyzed using log-rank tests. RESULTS: Among the 43 participants (mean age, 72.3 ± 7.9 years; 8 female), 17 met the BT criteria. We found no significant comorbidity-related differences in hypertension or diabetes between the BT(+) and BT(-) groups. Orthostatic hypotension was more prevalent in the BT(+) group than in the BT(-) group (47.1% vs 7.7%, p = 0.003). BT(+) patients were older with a lower early and delayed MIBG uptake; however, no significant differences were observed in DAT accumulation. Phenoconversion was observed in seven (41.2%) BT(+) and seven (26.9%) BT(-) patients. Three deaths were recorded in the BT(+) group (17.6%) and three in the BT(-) group (11.5%). No significant differences were observed in the risk of phenoconversion or mortality between the groups. CONCLUSIONS: We have identified the possibility that BT reflects cardiac sympathetic neurogenic denervation in patients with iRBD. Future research is needed to elucidate the potential prognostic value of BT.

Polysomnographic features prior to dream enactment behaviors in isolated rapid eye movement sleep behavior disorder.

OBJECTIVE: This study aimed to identify electroencephalogram correlates of dream enactment behaviors (DEBs) and elucidate their cortical dynamics in patients with isolated/idiopathic rapid eye movement (REM) sleep behavior disorder (iRBD). METHODS: This cross-sectional study included 15 patients with iRBD. Two REM sleep periods in routine polysomnography were compared: the 60 s preceding the DEBs ("pre-representative behavior" [preR]), and the 60 s with the least submental electromyogram activity ("background" [BG]). Six EEG frequency bands and electrooculogram were analyzed; power spectra, coherence and phase-locking values in four 15-s periods were examined to assess trends. These indices were also compared between preR and BG. RESULTS: Compared with BG, significantly higher delta power in the F3 channel and gamma power in the F4 and O2 channels were observed during preR. For functional connectivity, the widespread beta-band connectivity was significantly increased during preR than BG. CONCLUSION: Before notable REM sleep behaviors, uneven distributed higher EEG spectral power in both very low and high frequencies, and increased wide-range beta band functional connectivity, were observed over 60 s, suggesting cortical correlates to subsequent DEBs. SIGNIFICANCE: This study may shed light on the pathological mechanisms underlies RBD through the routine vPSG analysis, leading to detection of DEBs.

Corrigendum: Limited social support is associated with depression, anxiety, and insomnia in a Japanese working population.

[This corrects the article DOI: 10.3389/fpubh.2022.981592.].

Prevalence of depression or depressive state in patients with restless legs syndrome: A systematic review and meta-analysis.

Restless legs syndrome (RLS) is a common sleep-related disorder characterized by limb discomfort and the urge to move them when at rest, especially in the evening or at night. Although depression is often linked to various conditions, no systematic review has assessed depression prevalence in patients with RLS after the latest diagnostic criteria revision. This systematic review and meta-analysis aimed to investigate the depression and depressive state prevalence among patients with RLS. We systematically searched databases up to November 2022 and performed meta-analyses of the depression prevalence using a random-effects model and a meta-regression analysis to explore the relationship between the prevalence and severity of depression and factors such as age and RLS severity. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we analyzed 24 studies with 2039 patients. The pooled depression or depressive state prevalence, mostly defined by questionnaire scores, was 30.39 %. Nine studies reported the proportion of patients taking antidepressants (pooled rate: 3.41 %). No specific factors related to the prevalence or severity of depression were identified in patients with RLS. These findings highlight the significant prevalence of depression and underscore the need for future research with standardized diagnostic interviews and consistent methodologies across multi-site studies.

Mapping the landscape of sleep medicine training across Asia.

STUDY OBJECTIVES: This study assessed the current state of sleep medicine accreditation and training in Asia by conducting a comprehensive survey across 29 Asian countries and regions facilitated by the Asian Society of Sleep Medicine to identify existing gaps and provide recommendations for future enhancements. METHODS: The Asian Society of Sleep Medicine Education Task Force Committee designed a survey to gather data on accreditation, education, and training standards in sleep medicine, including information on challenges in enhancing education in the field. RESULTS: With an 86% (25 countries/regions) response rate, the survey showed that sleep medicine is recognized as an independent specialty in just 9 countries/regions (36% of the countries/regions surveyed). Ten countries/regions have established sleep medicine training programs, with Japan and Saudi Arabia offering it as a distinct specialty. Significant disparities in training and accreditation standards were identified, with many countries/regions lacking formalized training and practice guidelines. The survey also revealed that most local sleep societies across Asia support the development of an Asian Sleep Medicine Training Curriculum led by the Asian Society of Sleep Medicine. However, several barriers significantly impede the establishment and development of sleep medicine training programs, including the scarcity of trained specialists and technologists and the absence of national accreditation for sleep medicine. CONCLUSIONS: The survey highlights the need for standardized sleep medicine training and accreditation across Asia. Developing an Asian Sleep Medicine Training Curriculum and promoting Asian Society of Sleep Medicine accreditation guidelines are key recommendations. Implementing these strategies is essential for advancing sleep medicine as a widely recognized discipline throughout Asia. CITATION: BaHammam AS, Al-Abri MA, Abd Rashid R, et al. Mapping the landscape of sleep medicine training across Asia. J Clin Sleep Med. 2024;20(10):1647-1656.

The Inverse Association between the Frequency of Forest Walking (Shinrin-yoku) and the Prevalence of Insomnia Symptoms in the General Japanese Population: A Japan Multi-Institutional Collaborative Cohort Daiko Study.

Since a single forest walk (Shinrin-yoku or forest bathing) session is reported to improve sleep temporarily, occasional forest walks may have a positive effect on daily sleep. Therefore, this study aimed to examine whether more frequent forest walking is associated with better daily sleep conditions. Data from the second survey of the Japan Multi-Institutional Collaborative Cohort (J-MICC) Daiko Study conducted among residents of Nagoya City, Japan, were used. The study design was a cross-sectional study. In total, 2044 participants (529 men and 1515 women; age, mean ± standard deviation: 58.8 ± 9.9 years) were included in the analysis. Frequent forest walks were associated with a low percentage of insomnia symptoms (Insomnia Severity Index ≥10) in women, but not in men. The adjusted odds ratio for the group that rarely took forest walks with reference to the group that engaged in the activity once a month or more often was 2.04 (95% confidence interval: 1.29-3.23) in women. Forest walk frequency was not significantly associated with sleep duration or sleep efficiency as measured by actigraphy in either men or women. In conclusion, the results suggested that increasing the frequency of forest walks or Shinrin-yoku may be effective in preventing insomnia in women.

The effect of nonrestorative sleep on incident hypertension 1-2 years later among middle-aged Hispanics/Latinos.

BACKGROUND: Insomnia is known to be a major risk factor for incident hypertension. Nonrestorative sleep (NRS), which refers to insufficiently rested sleep, has reported to associate with various diseases. This study aimed to investigate the longitudinal association between insomnia-related symptoms including NRS and incident hypertension 1-2 years later by age group (young, 18-39 years and middle-age, 40-64 years) using existing cohort data involving Hispanics/Latinos. METHODS: This study included 1100 subjects who had participated in both the Hispanic Community Health Study/Study of Latinos and its follow-up study, the Sueño Ancillary Study, and met additional eligibility criteria. Incident hypertension was assessed by self-reported history and/or the use of antihypertensives. The Women's Health Initiative Insomnia Rating Scale (WHIIRS) was used to evaluate insomnia-related symptoms (difficulty initiating sleep, difficulty maintaining sleep, early morning awakening, difficulty returning to sleep, and NRS). Logistic regression analyses were conducted to assess the degree to which insomnia-related symptoms at baseline predicted incident hypertension. RESULTS: Among the participants (64% middle-aged, 36% young adults), 140 (12.7%) developed hypertension during the follow-up period. Among the sleep-related symptoms, only NRS predicted incident hypertension after adjusting for sociodemographic factors and physical condition (odds ratio: 1.88, 95% confidence interval: 1.10-3.21, p = 0.022) in middle-aged adults. None of the insomnia-related symptoms were associated with incident hypertension in the young adults. No association was found between WHIIRS-defined insomnia (total score ≥ 9) and incident hypertension in middle-aged adults or young adults. CONCLUSION: The present findings suggest the importance of focusing on NRS to help prevent the development of hypertension in middle-aged adults.

Transdiagnostic association between subjective insomnia and depressive symptoms in major psychiatric disorders.

In psychiatric disorders, comorbid depressive symptoms are associated with clinically important issues such as reduced quality of life, a poor prognosis, and increased suicide risk. Previous studies have found a close relationship between insomnia and depressive symptoms in major depressive disorder (MDD), and that actively improving insomnia heightens the improvement of depressive symptoms. This study aimed to investigate whether the association between insomnia and depressive symptoms is also found in other psychiatric disorders besides MDD. The subjects were 144 patients with MDD (n = 71), schizophrenia (n = 25), bipolar disorder (n = 22), or anxiety disorders (n = 26). Sleep status was assessed subjectively and objectively using the Athens Insomnia Scale (AIS) and sleep electroencephalography (EEG), respectively. Sleep EEG was performed using a portable EEG device. Depressive symptoms were assessed using the Beck Depression Inventory. Subjective insomnia, as defined by the AIS, was associated with depressive symptoms in all disorders. Moreover, in schizophrenia, a relation between depressive symptoms and insomnia was also found by objective sleep assessment methods using sleep EEG. Our findings suggest that the association between subjective insomnia and depressive symptoms is a transdiagnostic feature in major psychiatric disorders. Further studies are needed to clarify whether therapeutic interventions for comorbid insomnia can improve depressive symptoms in major psychiatric disorders, similar to MDD.

Association of Sleep Reactivity and Anxiety Sensitivity with Insomnia-Related Depression and Anxiety among City Government Employees in Japan.

It has recently been noted that a reduction in sleep reactivity, characterized as the trait-like degree to which exposure to stress interferes with sleep, and anxiety sensitivity are associated with reduced insomnia severity. This study aimed to examine whether sleep reactivity and anxiety sensitivity are associated with insomnia-related depression and anxiety among city government employees in Japan. This cross-sectional study included 1810 city government employees of Koka City, Japan (mean age (standard deviation): 45.33 (12.20) years) who completely answered the scales for sleep reactivity, anxiety sensitivity, anxiety, and depression. Stepwise multiple regression analysis adjusted for demographic data showed that anxiety sensitivity (ß = 0.39) was significantly linked to anxiety, and sleep reactivity (ß = 0.36) was significantly linked to depression in individuals with insomnia. Additionally, the results of a logistic regression analysis adjusted for demographic data showed that anxiety sensitivity and sleep reactivity were relevant factors for anxious insomnia (OR = 12.69) and depressive insomnia (OR = 8.73), respectively. Whereas both sleep reactivity (OR = 14.67) and anxiety sensitivity (OR = 6.14) were associated with combined insomnia. These findings indicate that sleep reactivity is strongly associated with depressive symptoms, and anxiety sensitivity is strongly associated with anxiety symptoms in individuals with insomnia.

Comparison of the usability of an automatic sleep staging program via portable 1-channel electroencephalograph and manual sleep staging with traditional polysomnography.

Automatic algorithms are a proposed alternative to manual assessment of polysomnography data for analyzing sleep structure; however, none are acceptably accurate for clinical use. We investigated the feasibility of an automated sleep stage scoring system called Sleep Scope, which is intended for use with portable 1-channel electroencephalograph, and compared it with the traditional polysomnography scoring method. Twenty-six outpatients and fourteen healthy volunteers underwent Sleep Scope and polysomnography assessments simultaneously. Polysomnography records were manually scored by three sleep experts. Sleep Scope records were scored using a dedicated auto-staging algorithm. Sleep parameters, including total sleep time, sleep latency, wake after sleep onset, and sleep efficiency, were calculated. The epoch-by-epoch pairwise concordance based on the classification of sleep into five stages (i.e., wake, rapid eye movement, N1, N2, and N3) was also evaluated after validating homogeneity and bias between Sleep Scope and polysomnography. Compared with polysomnography, Sleep Scope seemed to overestimate sleep latency by approximately 3 min, but there was no consistent tendency in bias in other sleep parameters. The Κ values ranged from 0.66 to 0.75 for experts' inter-rater polysomnography scores and from 0.62 to 0.67 for Sleep Scope versus polysomnography scores, which indicated sufficient agreement in the determination of sleep stages based on the Landis and Koch criteria. We observed sufficient concordance between Sleep Scope and polysomnography despite lower concordance in sleep disorder patients. Thus, this auto-staging system might serve as a novel clinical tool for reducing the time and expenses required of medical staff and patients. Supplementary Information: The online version contains supplementary material available at 10.1007/s41105-022-00421-5.

Correction to: Comparison of the usability of an automatic sleep staging program via portable 1-channel electroencephalograph and manual sleep staging with traditional polysomnography.

[This corrects the article DOI: 10.1007/s41105-022-00421-5.].

Limited social support is associated with depression, anxiety, and insomnia in a Japanese working population.

Background: Lack of social support is associated with depression, anxiety, and insomnia. This study aimed to determine the source of support related to depression, anxiety, and insomnia among Japanese workers. Methods: As part of a cohort study, we conducted a questionnaire survey among city government employees in Koka City, Shiga Prefecture, Japan, from September 2021 to March 2022. We used the Patient Health Questionnaire-9 (PHQ-9), Generalized Anxiety Disorder-7 (GAD-7), and Insomnia Severity Index (ISI) to assess depressive symptoms, anxiety symptoms, and insomnia, respectively. We used the Brief Job Stress Questionnaire (BJSQ) to assess job stressors and social support (from supervisors, colleagues, and family). Results: A total of 1,852 Japanese employees (38.4% male, 45.9 ± 12.9 years) participated in the survey, with 15.5, 10.8, and 8.2% of the participants having depressive symptoms (PHQ-9 ≥ 10), anxiety symptoms (GAD-7 ≥ 10), and insomnia (ISI ≥ 15), respectively. The logistic regression analysis suggested that job stressors were associated with depressive symptoms (p < 0.001), anxiety symptoms (p < 0.001), and insomnia (p = 0.009). In contrast, support from co-workers (p = 0.016) and family members (p = 0.001) was associated with decreased depressive symptoms. Support from family members was associated with decreased insomnia (p = 0.005). Conclusion: Social support from co-workers and family may be associated with reduced depressive symptoms, and family support may be associated with reduced insomnia in the Japanese working population. Clinical trial registration: https://clinicaltrials.gov/ct2/show/NCT03276585.

Irregular sleep and all-cause mortality: A large prospective cohort study.

OBJECTIVES: Previous studies using objective parameters have shown that irregular sleep is associated with the disease incidence, progression, or mortality. This study aimed to determine the association between subjective sleep duration and sleep regularity, with mortality in a large population. METHODS: Participants were from the Japan Multi-Institutional Collaborative Cohort study. We obtained information from each participant on sleep duration, sleep regularity, and demographics and overall lifestyle using self-administered questionnaires. We defined sleep regularity according to participants' subjective assessment of sleep/wake time regularity. Participants (n = 81,382, mean age: 58.1 ± 9.1years, males: 44.2%) were classified into 6 groups according to sleep duration and sleep regularity. Hazard ratios (HR) for time-to-event of death were calculated using the Cox proportional hazards model. RESULTS: The mean follow-up period was 9.1 years and the mean sleep duration was 6.6 h/day. Irregular sleep significantly increased the risk of all-cause mortality in all models compared with regular sleep (HR 1.30, 95% confidence interval; CI, 1.18-1.44), regardless of sleep duration. Multivariable analysis of the 6 groups by sleep pattern (sleep regularity and duration) showed irregular sleep and sleep durations of <6 h/day, 6 to <8 h/day, or ≥8 h/day were associated with a 1.2-1.5-fold increases in mortality, compared to regular sleep and sleep duration of 6 to <8 h/day. CONCLUSIONS: Our study shows an association between sleep irregularity and all-cause mortality in a large Japanese population. Our findings provide further confirmation of the need to consider not only sleep duration, but also the regularity aspect of sleep schedules.

The prevalence of depression in isolated/idiopathic rapid eye movement sleep behavior disorder: A systematic review and meta-analysis.

This systematic review and meta-analysis aimed to investigate depression prevalence and depression-related symptoms among patients with isolated/idiopathic rapid eye movement sleep behavior disorder (iRBD). We systematically searched online databases (PubMed and Scopus), performed meta-analyses of psychiatric symptoms prevalence using a random-effects model, and calculated 95% prediction intervals (PIs) and I2 values to evaluate the degree of heterogeneity. We conducted a meta-regression analysis to assess the relationship between psychiatric symptom severity, age at diagnosis, and disease duration from onset of iRBD. We analyzed 31 studies which included 3,576 patients (2,871 men, 80.3%; mean age, 66.6 ± 8.6 years). The pooled depression prevalence was 28.8% (95% CI 23.1-35.2, 95% PI 8.1-65.1, and I2 = 83.9%). We found a significantly negative correlation between depression-scale scores and disease duration in iRBD (p = 0.012, ß = -0.36, R2 analog = 0.33). Pooled prevalence of apathy and anxiety was 38.4% (95% CI 27.7-50.4, 95% PI 0.02-99.9, and I2 = 57.8%) and 21.3% (95% CI 15.5-28.5, 95% PI 4.2-62.6, and I2 = 47.1%), respectively. Few articles on alexithymia were available for meta-analysis. This study confirmed high prevalence of depression, apathy, and anxiety in patients with iRBD.

Idiopathic rapid eye movement sleep behavior disorder in Japan: An observational study.

INTRODUCTION: Idiopathic rapid eye movement sleep behavior disorder (iRBD) is one of the most specific prodromal symptoms of synucleinopathies, including Parkinson's disease (PD) and multiple system atrophy. The Japan Parkinson's Progression Markers Initiative (J-PPMI) was a prospective cohort study conducted in Japanese patients with iRBD to investigate biomarkers for prodromal synucleinopathies. We carried out an initial assessment of the J-PPMI study to reveal the factors correlated with dopamine transporter single-photon emission computed tomography (DaT) and 123I-meta-iodobenzylguanidine (MIBG) myocardial scintigraphy. METHODS: This cross-sectional study was conducted in 108 patients with iRBD, selected from the J-PPMI study. We divided the patients into four groups based on the MIBG and DaT results. We also recorded the patients' demographics and clinical data. Following PD probability calculation, we examined the biomarkers associated with DaT and MIBG. RESULTS: Ninety-five of the enrolled patients (88%) met the diagnostic criteria for prodromal PD based on the probability score. Only five patients had normal MIBG and DaT. We identified 29 cases with decreased DaT and MIBG, all of whom met the above diagnostic criteria. Both DaT and MIBG were significantly correlated with the Japanese version of the Montreal Cognitive Assessment (MoCA-J) score. CONCLUSION: Both DaT and MIBG are important biomarkers for confirming synucleinopathies and/or staging disease progression. Although 95% of iRBD patients were consistent with the body-first subtype concept, alpha-synuclein pathologies of iRBD might have widespread systemic involvement rather than being confined to the lower brainstem, particularly in patients with reduced MoCA-J scores.

R-R interval-based sleep apnea screening by a recurrent neural network in a large clinical polysomnography dataset.

OBJECTIVE: Easily detecting patients with undiagnosed sleep apnea syndrome (SAS) requires a home-use SAS screening system. In this study, we validate a previously developed SAS screening methodology using a large clinical polysomnography (PSG) dataset (N = 938). METHODS: We combined R-R interval (RRI) and long short-term memory (LSTM), a type of recurrent neural networks, and created a model to discriminate respiratory conditions using the training dataset (N = 468). Its performance was validated using the validation dataset (N = 470). RESULTS: Our method screened patients with severe SAS (apnea hypopnea index; AHI ≥ 30) with an area under the curve (AUC) of 0.92, a sensitivity of 0.80, and a specificity of 0.84. In addition, the model screened patients with moderate/severe SAS (AHI ≥ 15) with an AUC of 0.89, a sensitivity of 0.75, and a specificity of 0.87. CONCLUSIONS: Our method achieved high screening performance when applied to a large clinical dataset. SIGNIFICANCE: Our method can help realize an easy-to-use SAS screening system because RRI data can be easily measured with a wearable heart rate sensor. It has been validated on a large dataset including subjects with various backgrounds and is expected to perform well in real-world clinical practice.