Sleep最新文献

Study objectives: Isolated rapid eye movement sleep behavior disorder (iRBD) is recognized as a prodromal stage of alpha-synucleinopathies. Predicting phenoconversion in iRBD patients remains a key challenge. We aimed to investigate whether event-related potentials (ERPs) recorded during visuospatial attention tasks can serve as predictors of phenoconversion in iRBD patients.

Methods: We conducted a longitudinal study with 126 iRBD patients (aged 67.1 ± 6.4, 77 males) and 41 healthy controls (aged 66.1 ± 6.9, 29 males). Among the patients, those who further developed synucleinopathies during the follow-up period (average 6.3 years) were classified as converters (iRBD-CV), while the others were non-converters (iRBD-NC). Posner's visuospatial cueing task was performed at baseline. The N2 and P3 components were acquired for both the cue and target (valid and invalid) stimuli. Based on group comparisons, Kaplan-Meier survival analysis was performed.

Results: Twenty-nine patients converted to alpha-synucleinopathies (aged 69.4 ± 7.1, 14 males). iRBD patients exhibited overall reductions in N2 components for cue, valid, and invalid stimuli compared to HC (p = 0.012, 0.047, and 0.001, respectively). iRBD-CV patients displayed a significant increase in cue-elicited P3 (p < 0.001) and a decreasing trend in cue-elicited N2 (p = 0.079) compared to iRBD-NC. These ERP alterations were strongly associated with faster rate of phenoconversion (p < 0.001 for both components).

Conclusion: Our findings suggest that altered cue-elicited ERPs could serve as early biomarkers for predicting phenoconversion in iRBD patients, likely reflecting attention-related neurodegeneration pathways. These biomarkers potentially enable the detection of preclinical phenotypes in alpha-synucleinopathies, facilitating timely intervention.

Study objectives: Narcolepsy type 1 (NT1) is a chronic sleep-wake disorder, characterized by a loss of hypocretin production. Unexpectedly, in postmortem tissue of people with NT1, there is a loss of corticotrophin-releasing hormone (CRH) in the paraventricular nucleus. CRH is known as an activator of the hypothalamic-pituitary-adrenal axis in response to stress. This activation results in the release of the stress hormones adrenocorticotropic hormone (ACTH) and cortisol. We hypothesize an altered physiological and psychological stress response in NT1.

Methods: Participants were people with NT1 (n = 14) and matched healthy controls (n = 12). The Trier Social Stress Test for Groups (TSST-G), a validated socially evaluated stress test in controlled settings, induced acute stress. We measured ACTH and cortisol levels in the blood before and at three timepoints after the TSST-G. We also measured subjective stress and heart rate levels.

Results: In both groups, acute stress led to increases in ACTH (p = .006), cortisol (p < .001), heart rate (p < .001), and subjective stress (p < .001). Subjectively, people with NT1 experienced more stress than controls (p < .001). No differences were found in heart rate, cortisol, and ACTH between people with NT1 and controls at any timepoint. Secondary analyses showed that men with NT1 had lower cortisol levels immediately after stress induction than men in the control group (p = .002).

Conclusions: People with NT1 show an increased subjective stress response, but no changes in their endocrine or cardiovascular stress reactivity. Further research is required to determine the impact of reduced CRH production and gender in NT1.

Despite decades of research, defining insomnia remains challenging due to its complex and variable nature. Various diagnostic systems emphasize the chronic nature of insomnia and its impact on daily functioning, relying heavily on patient self-reporting due to limitations in objective measures such as polysomnography (PSG). Discrepancies between subjective experiences and objective PSG results highlight the need for more nuanced approaches, such as electroencephalogram (EEG) spectral analysis, which reveals distinct patterns of high-frequency activity in individuals with insomnia. This study explores EEG markers of insomnia by integrating subjective reports with objective physiological markers, specifically ORP (Odds-Ratio-Product) and spectral features, to address inconsistencies found in previous research and clinical settings. Qualitative and quantitative definitions of insomnia are contrasted to highlight differences in sleep architecture and EEG characteristics. The research aims to determine whether groups defined by weekly frequency and daily duration of symptoms have different distribution patterns and which physiological characteristics best distinguish insomnia patients from controls. Our findings suggest that ORP, as a dependent variable, captures the most significant differences in the independent variables across the model. Elevated beta power in insomnia patients indicates increased cortical arousal, supporting the perspective of insomnia as a hyperarousal disorder. Future research should focus on using ORP to enhance the understanding of sleep disturbances in insomnia. Comprehensive evaluation of insomnia requires integrating qualitative, quantitative, and neurophysiological data to fully understand its impact on sleep architecture and quality.

Study objectives: Obstructive sleep apnea (OSA) is associated with an increasing risk of cognitive impairment, but traditional hypoxic indicators can not accurately identify cognitive impairment. This study aimed to assess a new indicator, hypoxic burden, in cognitive impairment in OSA.

Methods: A total of 116 patients with OSA were enrolled in this study. Daytime sleepiness and cognition were assessed using the Epworth Sleepiness Scales and Montreal Cognitive Assessment (MoCA), respectively. All participants underwent polysomnography (PSG). The hypoxic burden was derived from PSG and calculated according to a specific algorithm. All the participants were divided into two groups. Seventy-seven were OSA with mild cognitive impairment (OSA + MCI), and 39 were OSA without mild cognitive impairment (OSA-MCI). The relationship between hypoxic burden and cognitive impairment was analyzed by establishing a series of logistic regression models.

Results: Hypoxic burden was higher in OSA + MCI group compared with OSA-MCI group, while there was no significance found for the apnea-hypopnea index between the two groups. After adjusting for various confounders, patients with OSA who had a higher total hypoxic burden and rapid eye movement-hypoxic burden in the fourth quartile were found to have an increased risk of MCI compared to those in the first quartile. The adjusted ORs were 7.69 (95% CI, 1.15 to 51.55) and 8.87 (95% CI, 1.22 to 64.34), respectively. However, There was no significant association between the other traditional hypoxic parameters and cognitive function after adjusting for various confounders.

Conclusions: Compared to the conventional hypoxic parameter, a higher hypoxic burden is associated with cognition and may be an important indicator for assessing MCI in OSA.

Study objective: Elevated nocturnal blood pressure (BP) increases the risk for hypertensive disorders of pregnancy (HDP). Though obstructive sleep apnea (OSA) increases the risk for HDP, data on OSA, and 24-hour ambulatory blood pressure monitoring (ABPM) in pregnancy are scarce. We aim to examine the BP profile of women with pregnancy-onset OSA.

Methods: Pregnant women with overweight/obesity and snoring were recruited at <13 weeks gestation and underwent level III home sleep apnea testing and 24-hour ABPM at enrollment and at 31-34 weeks' gestation. Women with OSA at enrollment were excluded. Mean differences in nocturnal BP and 24-hour BP measurements, between women with pregnancy-onset OSA and women without OSA, were computed by multivariable linear regression.

Results: Participants (40/101) had pregnancy-onset OSA (respiratory event index (REI) ≥5 events per hour) in the third trimester. Despite no significant differences in baseline BP, nocturnal systolic and diastolic BP were significantly higher in women with pregnancy-onset OSA compared to women without OSA, after adjusting for multiple covariates (mean difference 5.49 (1.45-9.52) and 3.89 (0.19-7.60), respectively). Differences in systolic BP persisted into the daytime in the OSA group. Lack of nocturnal dipping was highly prevalent in both groups, but the difference was not significant in the adjusted model.

Conclusions: Pregnancy-onset OSA in the 3rd trimester is associated with elevated nocturnal BP and daytime systolic BP. The lack of nocturnal dipping irrespective of REI cut-off in pregnant women at risk for SDB further demonstrates the limitations of REI in defining pathology in pregnancy.