Dream-enactment behaviours during the COVID-19 pandemic: an international COVID-19 sleep study.

There has been increasing concern about the long-term impact of coronavirus disease 2019 (COVID-19) as evidenced by anecdotal case reports of acute-onset parkinsonism and the polysomnographic feature of increased rapid eye movement sleep electromyographic activity. This study aimed to determine the prevalence and correlates of dream-enactment behaviours, a hallmark of rapid eye movement sleep behaviour disorder, which is a prodrome of α-synucleinopathy. This online survey was conducted between May and August 2020 in 15 countries/regions targeting adult participants (aged ≥18 years) from the general population with a harmonised structured questionnaire on sleep patterns and disorders, COVID-19 diagnosis and symptoms. We assessed dream-enactment behaviours using the Rapid Eye Movement Sleep Behaviour Disorder Single-Question Screen with an additional question on their frequency. Among 26,539 respondents, 21,870 (82.2%) answered all items that were analysed in this study (mean [SD] age 41.6 [15.8] years; female sex 65.5%). The weighted prevalence of lifetime and weekly dream-enactment behaviours was 19.4% and 3.1% and were found to be 1.8- and 2.9-times higher in COVID-19-positive cases, respectively. Both lifetime and weekly dream-enactment behaviours were associated with young age, male sex, smoking, alcohol consumption, higher physical activity level, nightmares, COVID-19 diagnosis, olfactory impairment, obstructive sleep apnea symptoms, mood, and post-traumatic stress disorder features. Among COVID-19-positive cases, weekly dream-enactment behaviours were positively associated with the severity of COVID-19. Dream-enactment behaviours are common among the general population during the COVID-19 pandemic and further increase among patients with COVID-19. Further studies are needed to investigate the potential neurodegenerative effect of COVID-19.

Effect of series of periodic limb movements in sleep on blood pressure, heart rate and high frequency heart rate variability.

INTRODUCTION: The phenomenon known as periodic limb movements in sleep (PLMS) has been linked to a change in autonomic nervous system (ANS) activity and its effect on circulatory regulation. Autonomic dysfunction or dysregulation in patients with PLMS has been described in some domains; however, any relationship between heart rate variability (HRV) and PLMS has not been clearly established. HRV analysis is a recognised, non-invasive research method that describes the influence of the ANS on heart rate (HR). The aim of our study was to further investigate the dysregulation of autonomic HR control in patients with PLMS. MATERIAL AND METHODS: We undertook a retrospective analysis of the polysomnographic (PSG), demographic and medical data of five patients with a total number of 1,348 PLMS. We analysed HR, HRV HF, systolic blood pressure (SBP), and diastolic blood pressure (DBP) for 10 heartbeats before the series of PLMS and 10 consecutive heartbeats as beat-to-beat measurements. The presented method of using successive, short, 10 RR interval segments refers to the time-frequency measurement, which is very clear and useful for presenting changes in the calculated parameters over time and thereby illustrating their dynamics. This method allowed us to assess dynamic changes in HRV HF during successive PLMS series. Statistical analysis was performed using IBM SPSS Statistics (v. 28.0.0.0). The Kruskal-Wallis test was performed to find statistically significant changes from baseline. RESULTS: No statistically significant changes in HR, SBP, or DBP were found in our group, although an increase in the value of the HRV HF was noted, suggesting an increase in intracardiac parasympathetic activity during the subsequent series of PLMS. CONCLUSIONS: Our study indicates an increase in parasympathetic activity during the appearance of successive PLMS, which, with the simultaneous lack of changes in HR, may suggest an increase in sympathetic activity, and therefore the appearance of so-called 'autonomic co-activation' resulting in the possibility of life-threatening cardiac events. CLINICAL IMPLICATIONS: Our findings add to the literature information regarding HRV in PLMS, and highlight the need for further studies to elucidate the effects of these conditions on the ANS, and on cardiovascular health.

KLB is associated with alcohol drinking, and its gene product ß-Klotho is necessary for FGF21 regulation of alcohol preference.

Excessive alcohol consumption is a major public health problem worldwide. Although drinking habits are known to be inherited, few genes have been identified that are robustly linked to alcohol drinking. We conducted a genome-wide association metaanalysis and replication study among >105,000 individuals of European ancestry and identified ß-Klotho (KLB) as a locus associated with alcohol consumption (rs11940694; P = 9.2 × 10-12). ß-Klotho is an obligate coreceptor for the hormone FGF21, which is secreted from the liver and implicated in macronutrient preference in humans. We show that brain-specific ß-Klotho KO mice have an increased alcohol preference and that FGF21 inhibits alcohol drinking by acting on the brain. These data suggest that a liver-brain endocrine axis may play an important role in the regulation of alcohol drinking behavior and provide a unique pharmacologic target for reducing alcohol consumption.

Orexins, Sleep, and Blood Pressure.

PURPOSE OF REVIEW: The aim of this review was to summarize collected data on the role of orexin and orexin neurons in the control of sleep and blood pressure. RECENT FINDINGS: Although orexins (hypocretins) have been known for only 20 years, an impressive amount of data is now available regarding their physiological role. Hypothalamic orexin neurons are responsible for the control of food intake and energy expenditure, motivation, circadian rhythm of sleep and wake, memory, cognitive functions, and the cardiovascular system. Multiple studies show that orexinergic stimulation results in increased blood pressure and heart rate and that this effect may be efficiently attenuated by orexinergic antagonism. Increased activity of orexinergic neurons is also observed in animal models of hypertension. Pharmacological intervention in the orexinergic system is now one of the therapeutic possibilities in insomnia. Although the role of orexin in the control of blood pressure is well described, we are still lacking clinical evidence that this is a possibility for a new approach in the treatment of cardiovascular diseases.

The prevalence of metabolic syndrome and metabolically healthy obesity in Europe: a collaborative analysis of ten large cohort studies.

BACKGROUND: Not all obese subjects have an adverse metabolic profile predisposing them to developing type 2 diabetes or cardiovascular disease. The BioSHaRE-EU Healthy Obese Project aims to gain insights into the consequences of (healthy) obesity using data on risk factors and phenotypes across several large-scale cohort studies. Aim of this study was to describe the prevalence of obesity, metabolic syndrome (MetS) and metabolically healthy obesity (MHO) in ten participating studies. METHODS: Ten different cohorts in seven countries were combined, using data transformed into a harmonized format. All participants were of European origin, with age 18-80 years. They had participated in a clinical examination for anthropometric and blood pressure measurements. Blood samples had been drawn for analysis of lipids and glucose. Presence of MetS was assessed in those with obesity (BMI ≥ 30 kg/m2) based on the 2001 NCEP ATP III criteria, as well as an adapted set of less strict criteria. MHO was defined as obesity, having none of the MetS components, and no previous diagnosis of cardiovascular disease. RESULTS: Data for 163,517 individuals were available; 17% were obese (11,465 men and 16,612 women). The prevalence of obesity varied from 11.6% in the Italian CHRIS cohort to 26.3% in the German KORA cohort. The age-standardized percentage of obese subjects with MetS ranged in women from 24% in CHRIS to 65% in the Finnish Health2000 cohort, and in men from 43% in CHRIS to 78% in the Finnish DILGOM cohort, with elevated blood pressure the most frequently occurring factor contributing to the prevalence of the metabolic syndrome. The age-standardized prevalence of MHO varied in women from 7% in Health2000 to 28% in NCDS, and in men from 2% in DILGOM to 19% in CHRIS. MHO was more prevalent in women than in men, and decreased with age in both sexes. CONCLUSIONS: Through a rigorous harmonization process, the BioSHaRE-EU consortium was able to compare key characteristics defining the metabolically healthy obese phenotype across ten cohort studies. There is considerable variability in the prevalence of healthy obesity across the different European populations studied, even when unified criteria were used to classify this phenotype.

Impact of REM Sleep Behavior and Sleep Talking on Mortality in Parkinson's Disease.

Background REM sleep behavior disorder (RBD) is a prodromal marker for Parkinson's disease (PD) and other alpha-synucleinopathies. Sleep talking (ST) is an isolated symptom and is frequent in PD and RBD. Here, we investigate the associations of ST and RBD with the mortality of PD patients. Patients and methods A total of 1,500 PD patients were randomly selected from the registry of the Finnish Parkinson's Association. Of the 855 that participated at baseline, 645 gave permission for follow-up studies. We gathered a completely filled sleep questionnaire and mortality information from 384 subjects. The Nelson-Aalen test and Cox hazard ratios (HR) were used for mortality analyses. Results The mean follow-up time was 4.3 years (0.3-7.0). PD patients with RBD or frequent ST had more non-motor symptoms. Depression, hallucinations, constipation, and excessive daytime sleepiness were more prevalent among subjects with RBD. Subjects with RBD and frequent ST (talking in their sleep ≥ once per week) had increased mortality (HR: 1.90, 95% CI: 1.18-3.06). RBD without frequent ST was not associated with mortality (HR: 0.77, 95% CI: 0.4-1.5). Frequent ST was associated with increased mortality when adjusted for age, PD duration, depression, gender, RBD, BMI, and hallucinations (HR: 2.22, 95% CI: 1.10-4.51). Additionally, age, duration of PD, arterial hypertension, and lower BMI were associated with increased mortality. Male gender, dopaminergic medication, depression, and hallucinations were not significantly associated with mortality. Conclusions RBD with frequent ST and ST alone appear to be risk factors for mortality in PD. Frequent ST may be a sign representing wider neurodegeneration. RBD subjects and frequent sleep talkers demonstrated more non-motor symptoms compared to PD without RBD or ST. Our findings have clinical implications. It remains to be seen if frequent ST indicates a poorer prognosis. Prospective studies are needed to find whether frequent ST is also a risk factor for developing PD.

A New Screening Tool (BAMSA) for Sleep Apnea in Male Professional Truck Drivers.

Obstructive sleep apnea (OSA) is common in professional truck drivers. It is important that OSA is recognized since undiagnosed and/or untreated sleep apnea is a risk factor for sleepiness-related traffic accidents. In this study, we developed a new simple tool to screen for obstructive sleep apnea (OSA) in this population. Altogether, 2066 professional truck drivers received a structured questionnaire. A total of 175 drivers had a clinical examination and were invited to participate in sleep laboratory studies, including cardiorespiratory polygraphy. We studied associations of different risk factors with the presence of sleep apnea. We established a new simple screening tool for obstructive sleep apnea (OSA) that was compared to other existing screening tools. A total of 1095 drivers completed the questionnaire. Successful cardiorespiratory polygraphy was obtained for 172 drivers. Full data were available for 160 male drivers included in the analyses. The following five risk factors for sleep apnea formed the BAMSA score (0 to 5): BMI > 30 kgm-2, age > 50 years, male gender, snoring at least one night per week, and the presence of apnea at least sometimes. BAMSA showed a sensitivity of 85.7% and a specificity of 78.8% in detecting AHI ≥ 15 when using a cut-off point of 4, and the ROC area was 0.823. BAMSA is a sensitive and easy-to-use tool in predicting obstructive sleep apnea in male professional drivers.

Heart Rate Variability and Interoception in Periodic Limb Movements in Sleep: Interference with Psychiatric Disorders?

Periodic limb movements in sleep (PLMS) are a prevalent disorder characterized by rhythmic, involuntary movements of the lower limbs, such as dorsiflexion of the ankle and extension of the big toe, occurring in periodic intervals during sleep. These movements are often linked to disrupted autonomic nervous system (ANS) activity and altered interoception. Interoception involves perceiving internal bodily states, like heartbeat, breathing, hunger, and temperature, and plays a crucial role in maintaining homeostasis and the mind-body connection. This review explores the complex relationships between PLMS, heart rate variability (HRV), ANS dysregulation, and their impact on psychiatric disorders. By synthesizing the existing literature, it provides insights into how ANS dysregulation and altered interoceptive processes, alongside PLMS, contribute to psychiatric conditions. The review highlights the potential for integrated diagnostic and therapeutic approaches and presents a cause-and-effect model illustrating the mutual influence of psychiatric disorders, ANS dysregulation, PLMS, and interoception.

Restless legs symptoms increased during COVID-19 pandemic. International ICOSS-survey.

BACKGROUND AND OBJECTIVES: Restless legs syndrome (RLS) has been associated with anxiety, depression, insomnia, lifestyle factors and infections. We aimed to study the prevalence of symptoms of RLS during the COVID-19 pandemic versus pre-pandemic. We hypothesized that pre-existing RLS symptoms worsened and pandemic-related factors may have triggered new symptoms of RLS. METHODS: Adults (≥18 years) from fifteen countries across four continents participated in an online survey between May and August 2020. The harmonized questionnaire included a validated single question on RLS with response alternatives from 1 to 5 on a scale from never to every/almost every evening or night. Other measures were the Insomnia Severity Index (ISI), measures of symptoms of anxiety (GAD-2) and depression (PHQ-2), and questions on different pandemic-related factors. RESULTS: Altogether, 17 846 subjects (63.8 % women) were included in the final analyses. The mean age was 41.4 years (SD 16.1). During the pandemic, symptoms of RLS (≥3 evenings/nights per week) were more common 9.1 % (95 % CI 8.7-10.1) compared to 5.4 % (95 % CI 4.9-6.0) before the pandemic (P < 0.0001). Alltogether 1.3 % (95 % CI 1.1-1.6) respondents had new-onset symptoms (≥3 evenings/nights per week). Moderate-severe insomnia was strongly associated with RLS symptoms. The occurrences of new-onset RLS symptoms were 5.6 % (95 % CI 0.9-13.0) for participants reporting COVID-19 and 1.1 % (95 % CI 0.7-1.5) for non-COVID-19 participants. In the fully adjusted logistic regression model, the occurrence of new-onset RLS symptoms was associated with younger age, social restrictions and insomnia severity. In a similar analysis, RLS symptoms (≥3 evenings/nights per week) were associated with lower education, financial hardship, sleep apnea symptoms, use of hypnotics, insomnia severity, symptoms of depression and possible post-traumatic stress disorder. DISCUSSION: Our findings indicate that RLS symptoms were more common during the pandemic than before. Usually, the prevalence of RLS increases with age. However, during the pandemic, new-onset symptoms of RLS were more common in younger age groups. This may be due to the pandemic-related factors being more pronounced in the younger compared to the older. The association between insomnia, psychiatric symptoms and RLS warrants clinical attention.

Patients with a Higher Number of Periodic Limb Movements Have Higher Nocturnal Blood Pressure.

There is growing evidence that periodic limb movements in sleep (PLMS) may lead to increased blood pressure (BP) values during the night. The aim of this study was to assess if patients with disordered sleep and an increased number of PLMS have higher BP values at night. We analyzed 100 polysomnographic (PSG) recordings of patients with disordered sleep, with the exclusion of sleep-related breathing disorders. Patients also registered beat-to-beat blood pressure during PSG. We compared the BP of patients with an increased number of PLMS (more than 5 PLMS per hour of sleep) during the night (examined group, n = 50) to the BP of patients with a PLMS number within the normal range (up to 5 PLMS per hour of sleep) (control group, n = 50). Patients from the examined group had significantly higher values of systolic BP during the night (119.7 mmHg vs. 113.3 mmHg, p = 0.04), sleep (119.0 mmHg vs. 113.3 mmHg, p = 0.04), and wake (122.5 mmHg vs. 117.2 mmHg, p = 0.04) periods and of diastolic BP during the night (75.5 mmHg vs. 70.6 mmHg, p = 0.04) and wake (77.6 mmHg vs. 71.5 mmHg, p = 0.01) periods. Our results suggest a relationship between the number of PLMS during the night and the values of nocturnal blood pressure. It is possible that their treatment could lower nocturnal BP in patients with sleep disorders, therefore improving their vascular risk profile.

Activating autoantibodies against G protein-coupled receptors in narcolepsy type 1.

STUDY OBJECTIVES: Narcolepsy type 1 is a rare hypersomnia of central origin, which is caused by loss of hypothalamic neurons that produce the neuropeptides hypocretin-1 and -2. Hypocretin-containing nerve terminals are found in areas known to play a central role in autonomic control and in pain signaling. Cholinergic M2 receptors are found in brain areas involved with the occurrence of hallucinations and cataplexy. In addition to classical symptoms of narcolepsy, the patients suffer frequently from autonomic dysfunction, chronic pain, and hypnagogic/hypnopompic hallucinations. We aimed to test whether narcolepsy type 1 patients have autoantibodies against autonomic ß2 adrenergic receptor, M2 muscarinic receptors, or nociception receptors. METHODS: We tested the serum of ten narcolepsy type 1 patients (five female) for activating ß2 adrenergic receptor autoantibodies, M2 muscarinic receptor autoantibodies, and nociception receptor autoantibodies. RESULTS: Ten of ten patients were positive for muscarinic M2 receptor autoantibodies (P < 0.001), 9/10 were positive for autoantibodies against nociception receptors (P < 0.001), and 5/10 were positive for ß2 adrenergic receptor autoantibodies (P < 0.001). CONCLUSIONS: Narcolepsy type 1 patients harbored activating autoantibodies against M2 muscarinic receptors, nociception receptors, and ß2 adrenergic receptors. M2 receptor autoantibodies may be related to the occurrence of cataplexy and, moreover, hallucinations in narcolepsy since they are found in the same brain areas that are involved with these symptoms. The occurrence of nociception receptor autoantibodies strengthens the association between narcolepsy type 1 and pain. The connection between narcolepsy type 1, autonomic complaints, and the presumed cardiovascular morbidity might be associated with the occurrence of ß2 adrenergic receptor autoantibodies. On the other hand, the presence of the autoantibodies may be secondary to the destruction of the hypocretin pathways.