REM Sleep Research Articles

Associations of accelerometer-measured physical activity, sedentary behaviour, and sleep with next-day cognitive performance in older adults: a micro-longitudinal study

BackgroundPrevious studies suggest short-term cognitive benefits of physical activity occurring minutes to hours after exercise. Whether these benefits persist the following day and the role of sleep is unclear. We examined associations of accelerometer-assessed physical activity, sedentary behaviour, and sleep with next-day cognitive performance in older adults.MethodsBritish adults aged 50-83 years (N = 76) without evidence of cognitive impairment or dementia wore accelerometers for eight days, and took daily cognitive tests of attention, memory, psychomotor speed, executive function, and processing speed. Physical behaviour (time spent in moderate-to-vigorous physical activity [MVPA], light physical activity [LPA], and sedentary behaviour [SB]) and sleep characteristics (overnight sleep duration, time spent in rapid eye movement [REM] sleep and slow wave sleep [SWS]) were extracted from accelerometers, with sleep stages derived using a novel polysomnography-validated machine learning algorithm. We used linear mixed models to examine associations of physical activity and sleep with next-day cognitive performance, after accounting for habitual physical activity and sleep patterns during the study period and other temporal and contextual factors.ResultsAn additional 30 min of MVPA on the previous day was associated with episodic memory scores 0.15 standard deviations (SD; 95% confidence interval = 0.01 to 0.29; p = 0.03) higher and working memory scores 0.16 SD (0.03 to 0.28; p = 0.01) higher. Each 30-min increase in SB was associated with working memory scores 0.05 SD (0.00 to 0.09) lower (p = 0.03); adjustment for sleep characteristics on the previous night did not substantively change these results. Independent of MVPA on the previous day, sleep duration ≥ 6 h (compared with < 6 h) on the previous night was associated with episodic memory scores 0.60 SD (0.16 to 1.03) higher (p = 0.008) and psychomotor speed 0.34 SD (0.04 to 0.65) faster (p = 0.03). Each 30-min increase in REM sleep on the previous night was associated with 0.13 SD (0.00 to 0.25) higher attention scores (p = 0.04); a 30-min increase in SWS was associated with 0.17 SD (0.05 to 0.29) higher episodic memory scores (p = 0.008).ConclusionsMemory benefits of MVPA may persist for 24 h; longer sleep duration, particularly more time spent in SWS, could independently contribute to these benefits.

REM disruption and REM vagal activity predict extinction recall in trauma-exposed individuals.

Accumulating evidence suggests that rapid eye movement sleep (REM) supports the consolidation of extinction memory. REM is disrupted in posttraumatic stress disorder (PTSD), and REM abnormalities after traumatic events increase the risk of developing PTSD. Therefore, it was hypothesized that abnormal REM in trauma-exposed individuals may pave the way for PTSD by interfering with the processing of extinction memory. In addition, PTSD patients display reduced vagal activity. Vagal activity contributes to the strengthening of memories, including fear extinction memory, and recent studies show that the role of vagus in memory processing extends to memory consolidation during sleep. Therefore, it is plausible that reduced vagal activity during sleep in trauma-exposed individuals may be an additional mechanism that impairs extinction memory consolidation. However, to date, the contribution of sleep vagal activity to the consolidation of extinction memory or any emotional memory has not been investigated. Trauma-exposed individuals (n = 113) underwent a 2-day fear conditioning and extinction protocol. Conditioning and extinction learning phases were followed by extinction recall 24 h later. The association of extinction recall with REM characteristics and REM vagal activity (indexed as heart rate variability) during the intervening consolidation night was examined. Consistent with our hypotheses, REM disruption was associated with poorer physiological and explicit extinction memory. Furthermore, higher vagal activity during REM was associated with better explicit extinction memory, and physiological extinction memory in males. These findings support the notion that abnormal REM, including reduced REM vagal activity, may contribute to PTSD by impairing the consolidation of extinction memory.

White matter hyperintensities and cholinergic degeneration as Lewy body disease.

Although basal forebrain (BF) cholinergic degeneration and white matter hyperintensities (WMHs) are important in neurodegeneration in Alzheimer's disease (AD) and dementia with Lewy bodies (DLB), their relationships with dopaminergic degeneration and clinical manifestations remain unclear. A total of 407 patients with cognitive impairment meeting the diagnostic criteria for AD, DLB, or both (AD+DLB) were assessed. All participants underwent 3T MRI, dopamine transporter (DAT) positron emission tomography, neuropsychological tests, and assessments for parkinsonism, cognitive fluctuation, visual hallucination, and rapid eye movement sleep behavior disorder (RBD). General linear and logistic regression models were used to investigate the relationships among BF volume, DAT uptake in the anterior caudate (DAT-AC), WMH volumes in anterior, posterior, periventricular, and deep regions, and clinical manifestations. DAT-AC was positively associated with BF volume and negatively associated with anterior periventricular WMH volume, but not with deep WMHs. Both deep and periventricular WMHs volumes were associated with hypertension and the number of microbleeds and lacunae. Lower BF volume and DAT-AC were independently associated with increased risk of cognitive fluctuation and visual hallucination, whereas lower DAT-AC was additionally associated with increased risk of RBD and greater parkinsonian severity. Both lower BF volume and DAT-AC were independently associated with widespread cognitive impairment, whereas higher anterior periventricular WMH volume was associated with executive dysfunction. BF cholinergic degeneration and anterior periventricular WMHs are closely associated with dopaminergic degeneration. Anterior periventricular WMHs may represent axonal alterations caused by the interplay between Lewy body-related degeneration and vascular pathologies.

Evolution of Sleep Apnea and Arousals in Patients with Ischemic Stroke: A Longitudinal Follow-Up Study.

Sleep-disordered breathing (SDB) is characterized by pauses or shallow breathing during sleep. It is linked to poorer outcomes and increased stroke recurrence in stroke patients. We aimed to evaluate the proportion, severity, type, and evolution of SDB and arousals in ischemic stroke patients. Ischemic stroke patients were recruited to evaluate SDB. Patients underwent overnight polysomnography (PSG) twice - within 1 month of stroke onset and again after 3 months. Clinical outcomes were evaluated at 6, 18, and 24 months. Of 141 acute ischemic stroke patients screened, 111 patients recruited in the study and 105 patients had technically adequate polysomnography. The mean age of patients was 50.5 years (standard deviation [SD]: 12.30), 78.4% of the patients were males, and the mean body mass index was 26 (SD: 5.4). Results showed that 81.9% had an apnea-hypopnea index (AHI) ≥5, with 12.5% having an AHI >30. The median arousal index (ArI) was 15.4 (interquartile range [IQR]: 0.5-50.5), which increased as the apnea increased. During follow-up, 56.8% patients had an AHI ≥5, with 12.5% having severe apnea. The median ArI decreased from 15.4 (IQR: 0.5-50.5) initially to 11.54 (IQR: 0.5-21.1) at follow-up. Numerical change in AHI severity categories were noted during the follow-up (mild: 8 vs 15; moderate: 17 vs 11; severe 19vs 7). For AHI >30, ArI decreased from 24.63 (IQR: 0.7-50.05) to 10.54 (IQR: 7.1-15.07) at follow-up. Sleep efficiency and rapid eye movement (REM) sleep duration increased on follow-up. The study showed a high proportion of SDB in acute ischemic stroke patients. In the follow-up, SDB improved, as reflected in AHI and ArI changes.

Cardiovascular autonomic dysfunction and sleep abnormalities in children with Prader-Willi syndrome.

Prader-Willi syndrome (PWS) is a rare genetic neurodevelopmental condition characterized by cognitive disabilities, behavioral problems, hypothalamic dysfunction with obesity, and sleep disorders. A few studies have reported autonomic nervous system dysfunction. Our aim was to investigate dysautonomia by combining sleep studies and standard autonomic testing in regularly followed children with PWS. In this retrospective study, heart rate variability was analyzed during each sleep stage (polysomnography) using time and frequency domains in PWS children (N = 37) compared with age-matched controls (N = 20). Cardiovascular autonomic testing (Ewing tests) and sweating assessment (electrochemical skin conductance) were also performed in patients over 6years (N = 23). Autonomic testing: Heart rate changes with active standing and with deep breathing were impaired in 47% and 22% of the children, respectively. Asymptomatic orthostatic hypotension (OH) was found in 26%. Baroreflex sensitivity in supine position was in normal range (14.1 ± 6.7ms/mmHg). Electrochemical skin conductance was normal. Sleep study: 46% of the children with PWS had obstructive sleep apnea and 24% had central sleep apnea. None of these events were observed in the control group. Mean R-R and time domain heart rate variability parameters were significantly lower compared with controls in N2 and Rapid Eye Movement (REM) sleep stages. Narcoleptic-like phenotype was found in 47% associated with lower low-frequency (LF) power (sympathetic index) in REM sleep. Our study confirms a decreased vagal modulation during both wakefulness and sleep in children with PWS. OH in some patients suggests a sympathetic dysfunction. These changes may contribute to the increased cardiovascular risk in PWS.

The QRS and T wave alternans — a new ECG pattern in Long QT syndrome

We present a case of a new ECG phenomenon that has not been described previously in patients with long QT syndrome (LQTS). Prolongation of the QT interval (QTc) to 568 ms were revealed in girl 6 years old on the resting ECG. There were no symptoms, syncope or family history of sudden death. A molecular genetic study revealed mutation «de novo» in the SCN5A gene (p.Val1411Met), a pathogenic class V that typical for the third molecular genetic variant of LQTS (LQT3). During Holter monitoring a «hyperadaptation» of the QT interval was noted (slope QT/RR 0.37 with normal limit till 0,24). New ECG pattern of the combination T wave alternans and QRS alternans (AT/AQRS) at the night sleep (possibly in REM sleep) were recorded. This pattern has not been described previously in patients with LQTS. Atenolol 1 mg/kg was prescribed. During therapy, AT/AQRS did not record after 2 months. Possible mechanisms and prognostic significance of the identified ECG pattern, issues of treatment of patients with LQT3 are discussed. Conclusions: Combined of T wave alternans and QRS alternans (AT/AQRS) is a new ECG pattern in patients with LQTS that is likely to increase the risk of cardiac events. “Hyperadaptation” of the QT interval may be one of the electrocardiological features of LQT3. The emergence of the AT/AQRS pattern during REM sleep makes this period perhaps the most dangerous for the development of cardiac events in patients with LQT3.

Fetal ECG-based analysis reveals the impact of fetal movements and maternal respiration on maternal-fetal heart rate synchronization

Identifying and understanding prenatal developmental disorders at an early stage are crucial as fetal brain development has long-term effects on an individual’s life. The maturation of the fetal autonomic nervous system (ANS) is believed to influence the coordination and direction of maternal-fetal heartbeat synchronization. Fetal behavioral states (FBSes) include quiet sleep (1F), active sleep (2F), quiet awake (3F), and active awake (4F). In this study, the focus is on fetal movements, leading to the grouping of 1F and 3F into a quiet state, while 2F and 4F are combined to form an active state. Thus, the FBSes discussed in this article consist of fetal quiet and active states. Here, we explore the relationship between FBSes and the coupling of maternal and fetal heartbeats. We also seek to understand how maternal breathing patterns influence this coupling while considering FBSes. The study involved 105 healthy fetuses with gestational ages (GA) from 20 to 40 weeks. Non-invasive electrocardiogram (ECG) signals were recorded for 3 to 10 minutes. The ECG samples were separated into three gestational groups (Early: 16 ≤ GA &lt; 25, Mid: 25 ≤ GA &lt; 32, and Late: 32 ≤ GA &lt; 40 weeks). Maternal respiration rate and coupling strength parameters were calculated for various maternal-fetal heartbeat coupling ratios. The findings of the study indicated that FBSes influenced maternal-fetal HR coupling strength during late gestation but not during early and mid-gestation. The changes in maternal-fetal HR synchronization or communication as gestation progresses occur in both FBSes. Furthermore, we noticed a significantly higher level of maternal-fetal heartbeat synchronization during periods of higher respiratory rates when the fetus was in a quiet state. These results emphasize how FBSes impact the synchronization of maternal-fetal HR and contribute to the understanding of fetal growth and health.

Sensitivity and specificity of a seed amplification assay for diagnosis of multiple system atrophy: a multicentre cohort study

The pathological hallmarks of multiple system atrophy and Parkinson's disease are, respectively, misfolded-α-synuclein-laden glial cytoplasmic inclusions and Lewy bodies. CSF-soluble misfolded α-synuclein aggregates (seeds) are readily detected in people with Parkinson's disease by α-synuclein seed amplification assay (synSAA), but identification of seeds associated with multiple system atrophy for diagnostic purposes has proven elusive. We aimed to assess whether a novel synSAA could reliably distinguish seeds from Lewy bodies and glial cytoplasmic inclusions. In this multicentre cohort study, a novel synSAA that multiplies and detects seeds by fluorescence was used to analyse masked CSF and brain samples from participants with either clinically diagnosed or pathology-confirmed multiple system atrophy, Parkinson's disease, dementia with Lewy bodies, isolated rapid eye movement sleep behaviour disorder (IRBD), disorders that were not synucleinopathies, or healthy controls. Participants were from eight available cohorts from seven medical centres in four countries: New York Brain Bank, New York, USA (NYBB); University of Pennsylvania, Philadelphia, PA, USA (UPENN); Paracelsus-Elena-Klinik, Kassel, Germany (DeNoPa and KAMSA); Hospital Clinic Barcelona, Spain (BARMSA); Universität Tübingen, Tübingen, Germany (EKUT); Göteborgs Universitet, Göteborgs, Sweden (UGOT); and Karolinska Institutet, Stockholm, Sweden (KIMSA). Clinical cohorts were classified for expected diagnostic accuracy as either research (longitudinal follow-up visits) or real-life (single visit). Sensitivity and specificity were estimated according to pathological (gold standard) and clinical (reference standard) diagnoses. In 23 brain samples (from the NYBB cohort), those containing Lewy bodies were synSAA-positive and produced high fluorescence amplification patterns (defined as type 1); those containing glial cytoplasmic inclusions were synSAA-positive and produced intermediate fluorescence (defined as type 2); and those without α-synuclein pathology produced below-threshold fluorescence and were synSAA-negative. In 21 pathology-confirmed CSF samples (from the UPENN cohort), those with Lewy bodies were synSAA-positive type 1; those with glial cytoplasmic inclusions were synSAA-positive type 2; and those with four-repeat tauopathy were synSAA-negative. In the DeNoPa research cohort (which had no samples from people with multiple system atrophy), the novel synSAA had sensitivities of 95% (95% CI 88-99) for 80 participants with Parkinson's disease and 95% (76-100) for 21 participants with IRBD, and a specificity of 95% (86-99) for 60 healthy controls. Overall (combining BARMSA, EKUT, KAMSA, UGOT, and KIMSA cohorts that were enriched for cases of multiple system atrophy), the novel synSAA had 87% sensitivity for multiple system atrophy (95% CI 80-93) and specificity for type 2 seeds was 77% (67-85). For participants with multiple system atrophy just in research cohorts (BARMSA and EKUT), the novel synSAA had a sensitivity of 84% (95% CI 71-92) and a specificity for type 2 seeds of 87% (74-95), whereas cases from real-life cohorts (KAMSA, KIMSA, and UGOT) had a sensitivity of 91% (95% CI 80-97) but a decreased specificity for type 2 seeds of 68% (53-81). The novel synSAA produced amplification patterns that enabled the identification of underlying α-synuclein pathology, showing two levels of fluorescence that corresponded with different pathological hallmarks of synucleinopathy. The synSAA might be useful for early diagnosis of synucleinopathies in clinical trials, and potentially for clinical use, but additional formal validation work is needed. Michael J Fox Foundation for Parkinson's Research, Amprion.

Neither fifty percent slow-wave sleep suppression nor fifty percent rapid eye movement sleep suppression does impair memory consolidation

Establishing well-defined relationships between sleep features and memory consolidation is essential in comprehending the pathophysiology of cognitive decline commonly seen in patients with insomnia, depression, and other sleep-disrupting conditions.Twenty-eight volunteers participated in two experimental sessions: a session with selective SWS suppression during one night and a session with undisturbed night sleep (as a control condition). Fifteen of them also participated in a third session with REM suppression. Suppression was achieved by presenting an acoustic tone. In the evening and the morning, the participants completed procedural and declarative memory tasks and the Psychomotor vigilance task (PVT). Heart rate variability analysis and salivary cortisol were used to control possible stress reactions to sleep interference.SWS and REM suppression led to more than 50 percent reduction in the amount of these stages. Neither vigilance nor memory consolidation was impaired after SWS or REM suppression. Unexpectedly, a beneficial effect of selective SWS suppression on PVT performance was found. Similarly, after a night with SWS suppression, the overnight improvement in procedural skills was higher than after a night with REM suppression and after a night with undisturbed sleep.Our data brings into question the extent to which SWS and REM are truly necessary for effective memory consolidation to proceed. Moreover, SWS suppression may even improve the performance of some tasks, possibly by reducing sleep inertia associated with undisturbed sleep.

The correlation between rapid eye movement sleep and nocturnal hypertension in patients with obstructive sleep apnea: A retrospective study.

Obstructive sleep apnea (OSA) is a respiratory disease closely associated with hypertension and heart disease. This study aimed to evaluate the diagnostic value of rapid eye movement (REM) sleep during nocturnal hypertension in OSA patients. We selected 194 patients who underwent polysomnography (PSG) at the Respiratory and Critical Care Medicine Department of Jiading District Central Hospital in Shanghai between January 2021 and August 2023. All patients were assigned to the hypertension and normal blood pressure groups, and the differences between the 2 groups were compared. This study included 194 patients (137 with nocturnal hypertension and 57 with normal nocturnal blood pressure). The proportion of male sex, body mass index, apnea-hypopnea index (AHI), REM sleep duration, percentage of REM sleep duration to total sleep duration, REM-AHI, nonrapid eye movement-AHI, oxygen desaturation index (ODI), REM-ODI, nonrapid eye movement-ODI, and average nighttime heart rate during sleep were higher in the hypertension group than in the normal blood pressure group, and the lowest oxygen saturation was lower than that in the normal blood pressure group (P < .05). Logistic regression analysis showed that REM-AHI was an independent risk factor for nocturnal hypertension (adjusted odds ratio, 1.048; 95% confidence interval, 1.011-1.086; P = .01). Receiver operating characteristic curve analysis showed that the REM-AHI had an area under the curve of 0.721 (95% confidence interval, 0.641-0.801; P < .001) for diagnosing nocturnal hypertension in patients with OSA, with a maximum Youden index of 0.379. The optimal critical value of the REM-AHI was 23.6 times/h, with a sensitivity of 64.2% and specificity of 73.7%. REM sleep is closely related to nocturnal hypertension, and patients with OSA are more prone to cardiovascular events.

Characteristics of psychiatric patients with nightmares after suvorexant administration: A retrospective study.

Suvorexant is an orexin receptor antagonist (ORA) for the treatment of insomnia. The antagonistic action of suvorexant on orexin receptors is associated with an increase in rapid eye movement (REM) sleep, which can potentially lead to nightmares depending on the patient's condition. However, the precise risk factors for nightmares among patients taking ORAs, such as suvorexant, have yet to be identified. In this retrospective study, we aimed to identify the risk factors for the development of nightmares in patients treated with suvorexant. The risk factors were determined by comparing parameters between the nightmare group and the nonnightmare group. This study included 440 patients who received suvorexant at the University of Miyazaki Hospital from April 2014 to January 2021. We found that 9.1% (n = 40) of the patients experienced suvorexant-induced nightmares. There was a significant difference in the median age, which was lower in the nightmare group than in the nonnightmare group (p < 0.01). Furthermore, both multiple logistic regression analysis and Cox proportional hazards regression analysis revealed increased odds ratios for nightmares for individuals aged 20-39 years. This study revealed that elderly patients taking suvorexant had fewer nightmares than nonelderly patients did.

Using Cannabis and CBD to Sleep: An Updated Review.

Cannabis sativa and constituent cannabinoids are in widespread use for the treatment of sleep disorders where many patients desire pharmacotherapy. Previous reviews highlight a lack of high-quality evidence to support the efficacy and long-term safety of cannabinoids in various conditions. We aim to provide an update of recent original research evaluating cannabinoid-based therapeutics in sleep disorders. We identified twenty-one recent studies of cannabinoids for insomnia, subjective sleep impairment, obstructive sleep apnoea, rapid eye movement sleep behaviour disorder, and restless legs syndrome. We note trends towards the use of minor cannabinoids, studies using decentralised approaches and increased utilisation of objective measures in clinical trials. The evidence-base does not match widespread use of cannabinoids for the treatment of sleep disorders. There is a growing need for adequately funded well-designed clinical trials with longer treatment durations and decent sample sizes to inform both the clinician and patient.

Semi automatic quantification of REM sleep without atonia in natural sleep environment

Polysomnography, the gold standard diagnostic tool in sleep medicine, is performed in an artificial environment. This might alter sleep and may not accurately reflect typical sleep patterns. While macro-structures are sensitive to environmental effects, micro-structures remain more stable. In this study we applied semi-automated algorithms to capture REM sleep without atonia (RSWA) and sleep spindles, comparing lab and home measurements. We analyzed 107 full-night recordings from 55 subjects: 24 healthy adults, 28 Parkinson’s disease patients (15 RBD), and three with isolated Rem sleep behavior disorder (RBD). Sessions were manually scored. An automatic algorithm for quantifying RSWA was developed and tested against manual scoring. RSWAi showed a 60% correlation between home and lab. RBD detection achieved 83% sensitivity, 79% specificity, and 81% balanced accuracy. The algorithm accurately quantified RSWA, enabling the detection of RBD patients. These findings could facilitate more accessible sleep testing, and provide a possible alternative for screening RBD.

Noise-sensitivity during sleep in non-sedated mechanically ventilated patients is associated with weaning duration: a polysomnographic study.

Poor sleep is a major concern in intensive care units (ICUs), particularly in mechanically ventilated patients, because it is associated with longer duration of the weaning phase and higher mortality. High noise levels in ICUs are frequently reported by patients as one of the most disturbing sleep-disrupting factors but would be responsible for less than 20% of arousals. This suggests major inter-individual variability in noise sensitivity. Our objectives were to define and assess noise sensitivity in mechanically ventilated patients and to explore its association with sleep duration, sleep quality and weaning duration. We retrospectively re-analyzed polysomnographies (PSGs) recorded in 29 non-sedated patients, mechanically ventilated for at least 24h and difficult to wean (i.e. ≥ 1 spontaneous breathing trial failure). All the arousals were identified on all the PSGs. We calculated mean noise level and identified all noise peaks (an abrupt increase of noise intensity of more than 10 decibels (dBA)) preceding each arousal. Each 21-second period preceding each arousal was divided into seven 3-second bins. We built a pre-event time histogram for each PSG by counting the total number of noise peaks in each bin. If the total number of noise peaks in one bin exceeded the average of the seven bins plus 2 SD, we considered that there was a significant relationship between the number of noise peaks in this bin and the arousal. The patient was then considered as noise-sensitive. Presence of atypical sleep, proportion of sleep stages, and weaning duration were assessed. Nineteen out of 29 patients (66%) were noise-sensitive. Duration of weaning from ventilator was significantly longer in noise-insensitive patients (median [interquartile range] 2 [1-2] versus 5 [2-8] days; p < 0.01). Proportion of N1, N2, N3 sleep stages and rapid eye movement sleep were similar in noise-sensitive and noise-insensitive patients. In contrast, the proportion of patients displaying atypical sleep was higher in noise-insensitive patients. Our results report for the first time that most ICU patients were noise-sensitive. Lower noise sensitivity was associated with atypical sleep and could reflect lower brain reactivity to environment.

Cholinergic modulation of upper airway control: maturational changes and mechanisms at cellular and synaptic levels.

Respiration is governed by a central rhythm and pattern generator, which has the preBötzinger complex as the inspiratory oscillator initiating the coordinated activity of several respiratory muscles, including the diaphragm, intercostals, and upper airway muscles. The diaphragm is the main inspiratory pump muscle driving inflow, while dilator upper airway muscles, such as tongue muscles, reduce airway resistance during inspiration. Breathing exhibits a marked state-dependent pattern attributed to changes in neuromodulatory tone in respiratory-related brain regions, including decreases in noradrenaline and serotonin and increases in acetylcholine levels during rapid eye movement (REM) sleep. Here, we discuss respiratory modulation by acetylcholine acting on its metabotropic muscarinic receptors, focusing on the regulation of upper airway muscle activity during sleep and wakefulness and its changing effects with postnatal maturation. We focus on experimental data examining muscarinic receptor distribution patterns, the ion channels they modulate, and how these distribution patterns change with postnatal maturation. We also consider experimental data highlighting cholinergic cellular and synaptic effects on hypoglossal motoneurons and preBötzinger Complex neurons, and how that might explain changes in the effects of cholinergic modulation with development. Overall, this discussion is critical to comprehend the postnatal maturation in the cholinergic modulation of the respiratory control system leading to opposing effects of muscarinic receptors on upper airway muscle activity in neonate (excitatory) and adult (inhibitory) preparations. The changes in cholinergic pathways associated with dysfunctional upper airway patency control will also be discussed in the context of pathologies, such as sleep-disordered breathing.

Rapid eye movement (REM)-related obstructive sleep apnea and hypertension: insights from the clinical spectrum of apnea-hypopnea index ratios across REM and non-REM sleep stages in a Chinese cohort.

Previous studies have linked sleep-disordered breathing during rapid eye movement (REM) sleep to hypertension. However, no standardised definition of REM-related obstructive sleep apnea (REM-OSA) exists. This study aimed to evaluate whether the ratio of the apnea-hypopnea index (AHI) in REM to that in non-REM (NREM) (REM-AHI/NREM-AHI) accurately identifies patients with OSA comorbid with hypertension. We screened 1439 participants and included 790 patients with OSA. REM-OSA was defined as AHI ≥5 events/h, REM-AHI/NREM-AHI ≥2, and REM stage ≥30 min. Differences between REM-OSA and NREM-OSA groups, and among quartiles of REM-AHI/NREM-AHI, were assessed. The impact of REM-AHI/NREM-AHI on hypertension was assessed by logistic regression and restricted cubic spline analysis. Overall, patients with REM-OSA, as traditionally defined, had a lower hypertension prevalence, lower blood pressure, and milder OSA. Patients with REM-AHI/NREM-AHI <2 but a higher total AHI had a higher prevalence of hypertension. The highest REM-AHI/NREM-AHI quartile had the mildest OSA and the lowest hypertension prevalence. In subgroups restricted by total AHI or NREM-AHI, a similar trend existed, suggesting that total AHI appeared more influential on hypertension than the predominance of REM-AHI. Restricted cubic spline analysis certified a non-linear relationship between REM-AHI/NREM-AHI and total AHI, blood pressure and hypertension prevalence. Our research showed that patients with REM-OSA defined by REM-AHI/NREM-AHI ≥2 are not the subgroup with the highest hypertension prevalence within the entire OSA population. It is important to avoid focusing solely on the REM-AHI/NREM-AHI ratio and overlooking the overall severity of OSA, which could lead to missing groups that also have a high prevalence of hypertension.

Illnesses and sleep deprivation

Introduction: Sleep is defined on the basis of behavioural and physiological criteria dividing it into two states : non rapid eye movement (NREM) sleep which is subdivided into three stages (N1,N2,N3) abs rapid eye movement (REM) sleep characterized by rapid eye movements, muscle atonia and desynchronized EEG [1]. The most important step in assessing a patient with a sleep complaint is obtaining a detailed history including family and previous histories. Material and Methods: There were analyzed articles from PubMed database from the last 5 years 2019-2024, mentioned such words as “illnesses”, “sleep deprivation” [2]. As well as scientific works that have not lost their relevance today [3-6]. Results: For example, critically ill patients frequently experience poor sleep, characterized by frequent disruptions, loss of circadian rhythms and pancity of time spent in restorative sleep stages. Factors that are associated with sleep stages. One of them is critical condition in the intensive care unit ICU include patient-ventilator dyssynchrony, medications, patient care and interactions environmental noise and light [ 7-24]. Along with ICU patients, also medical human resources ICU suffer from sleep disorders due to psycho-emotional burnout (PEB) [25] and chronic fatigue syndrome [7], sometimes not different from wartime PEB [ 26]. Conclusion: Sleep disturbance during intensive care unit admission is common. Sleep disturbance has been observed in survivors of critical illness even after transfer out of the ICU. Sleep disturbance is common in critically ill patients up to 12 months after hospital discharge. Like, and medical human resources ICU, may suffer from sleep problems throughout their lives.

Phenoconversion in Women and Men With Isolated REM Sleep Behavior Disorder: A Retrospective Cohort Study.

Isolated REM sleep behavior disorder (iRBD) is strongly associated with synucleinopathies. Previous iRBD cohort studies have primarily focused on older (>50 years), male-predominant cohorts. Risk of phenoconversion in women and younger adults remains unclear. The study aimed to determine clinical features associated with conversion to a defined neurodegenerative disorder in women and men with iRBD. One hundred eighty-six women and 186 men with iRBD were matched by polysomnography month. Baseline clinical variables and subsequent neurodegenerative outcomes were abstracted by chart review. Kaplan-Meier curves assessed conversion rates. Cox proportional hazards modeling evaluated factors associated with phenoconversion risk. Age at iRBD diagnosis was younger in women compared with men (54.9 vs 62.5 years, p < 0.01). Forty-eight patients (12.9%), including 18 women (9.7%) and 30 men (16.1%), phenoconverted during a median follow-up of 6.0 years. Conversion rates were lower in antidepressant users and patients with chronic pain or psychiatric comorbidity while rates were higher in those with vascular comorbidity. Only age at diagnosis (HR 1.09, 95% CI 1.06-1.13) was associated with phenoconversion after adjusting for RBD symptom duration; sex; antidepressant use; and psychiatric, chronic pain, and vascular comorbidities. Age at diagnosis was independently associated with phenoconversion risk in women and men with iRBD.

Obstructive sleep apnea in 12 to 24 months old toddlers referred for sleep study in a tertiary care center.

To assess OSA prevalence, comorbidities, and the influence of sleep stages and body positions on respiratory events distribution in toddlers aged 12-24 months. A single center retrospective study that included toddlers aged 12-24 months old who underwent overnight PSG. OSA severity was categorized by obstructive apnea-hypopnea index (OAHI) as mild (1-4.9 events/h), moderate (5-9.9 events/h), and severe (≥ 10 events/h). 283 PSG data were included with a median age of 18 months (IQR 16-20.25) for the OSA group (168/283) and 19 months (IQR 16-22) for the non-OSA group (115/283) (p = 0.047). OSA prevalence was 68.5% (42.3% mild, 18.5% moderate, and 39% severe). 38.1% of children had no comorbidities, 24.4% had a history of prematurity and 11.3% had Down syndrome. Multivariate binominal regression analysis showed that children with history of prematurity (p = 0.017) and Down syndrome (p = 0.043) had higher odds of having OSA. The mean SaO2 in REM sleep was lower, and the mean time spent with oxygen saturation below 90% was higher in children with neuromuscular disease compared to those with other comorbidities. In toddlers without comorbidities, the median REM OAHI was 29.8 events/h (IQR: 58.48), whereas the median non-REM OAHI was 4.1 events/h (IQR: 10.4 p < 0.001). Supine OAHI was 7.9 (IQR: 24.9), and off supine OAHI was 10.5 (IQR: 18.1, p = 0.407). In toddlers aged 12-24 months, history of prematurity and Down syndrome were significantly associated with OSA. Obstructive respiratory events occurred predominantly in REM sleep, and no significant positional relations were noted.

Associations between Sleep, Energy Balance and Obesity Markers over 6 Months in Black Emerging Adults - Pilot Study Findings from the Sleep, Health Outcomes and Body Weight (SHOW) Study.

Insufficient sleep (short sleep duration and poor sleep quality) is associated with obesity risk. Emerging adults (ages 18-28 years) have a greater risk of excess weight gain and insufficient sleep, and these risks are higher in Black individuals. Using a measurement burst design, we assessed associations between sleep with energy balance components and obesity marker changes over 6 months in 15 Black emerging adults (12 females; age 21±2.5 years; body mass index 25.7±4.5 kg/m2; body fat 25.8±11.9%). Since our sample was predominantly female (80%), we repeated our analyses for females only. Participants completed the following measurements at baseline (BLN) and 6 months later (6MO): 7 days of actigraphy-based sleep and physical activity energy expenditure (EE) and 2 nights of in-home polysomnography-based sleep; resting EE and thermic effect of food with indirect calorimetry; ad libitum energy intake (EI) via self-reported methods over 4 days and directly measured over 3 days with provided meals. Body weight (2.6 kg, p=0.01) and waist circumference (2.4 cm, p=0.03) increased from BLN to 6MO. Changes in actigraphy-based sleep duration were associated with changes in body weight (β=0.03, Standard error (SE)=0.02, p=0.04) and fat mass (β=0.07, SE=0.03 p=0.03) in females only. Greater rapid eye movement sleep duration was associated with increases in resting EE (β=2.24, SE=0.84, p=0.02). Greater slow-wave sleep was associated with increases in self-reported EI (β=18.34, SE=4.7, p<0.01). Sleep may impact components of energy balance and risk of weight gain in Black emerging adults. Additional research is needed to confirm our pilot findings.