Sleep and Biological Rhythms最新文献

Abstract

Currently hypoglossal nerve–genioglossus axis is the major research core of OSA pathogenesis. The pathogenesis of OSA incidence changes before and after menopause needs to be clarified further. Little is known about the influences of ovariectomy on hypoglossal motoneurons. In the research, we utilized a rat ovariectomy model to evaluate the expression changes of 5-HT_2A and α₁-Adrenergic receptors in the hypoglossal nucleus and to explore the involvement of BDNF/TrkB signaling and endoplasmic reticulum molecular chaperones in the hypoglossal nucleus. Results indicated that the expression of 5-HT_2A and α₁-Adrenergic receptors reduced dramatically in the hypoglossal nucleus of ovariectomized rats. The apoptosis level of hypoglossal motor neurons increased markedly in the OVX groups. The up-regulated expression of BDNF and down-regulated expression of TrkB were found in the OVX groups. Ovarian insufficiency resulted in the activation of UPR and the loss of CANX-CALR cycle. Estrogen replacement could restore these changes partially. Estrogen level influences the expression of neurotransmitter receptors, and regulates BDNF/TrkB signaling compensation and endoplasmic reticulum homeostasis, which might be one of the pathogenesis of menopausal female OSA. The results reveal a new perspective for studying female OSA from the view of hypoglossal nerve and hormonal changes and attempt to propel 17β-estradiol toward a feasible therapy for female OSA.

There is limited research on the circadian rhythm and sleep state in patients with acute cerebral infarction (ACI) accompanied by sleep-breathing disorders (SDB). This study aims to provide a scientific basis for individualized diagnosis and treatment for stroke-related SDB patients. The SC-500 sleep monitor was used to continuously monitor 1367 ACI patients over 5 days. Based on the apnea–hypopnea index (AHI), patients were divided into non-SDB group (normal) and SDB group (mild, moderate, severe, fluctuating). Interdaily stability (IS) and intradaily variability (IV) were calculated through heart rate monitoring, and sleep states and their correlations were analyzed. Compared to the non-SDB group, patients with moderate-to-severe ACI accompanied by SDB showed decreased IS, increased IV, and sleep fragmentation. Significant statistical differences were observed in total sleep time (TST), rapid eye movement latency (REML), sleep efficiency (SE), non-rapid eye movement stages 1–2 (NREM stages1–2), non-rapid eye movement stages 3–4 (NREM stages 3–4), proportion of non-rapid eye movement (NREM%), wake after sleep onset (WASO), and number of awakenings (NOA) between the SDB group and the non-SDB group (P < 0.05). AHI showed a strong negative correlation with IS and a strong positive correlation with IV. AHI was positively correlated with sleep latency (SL), REML, NREM stages1–2, NREM%, proportion of rapid eye movement (REM%), WASO, time out of bed (TOB), and NOA, and negatively correlated with TST, SE, NREM stages 3–4, and rapid eye movement (REM), all with statistical significance (P < 0.05). There were significant statistical differences in the Mini-Mental State Examination (MMSE) between patients with and without SDB, and among mild, moderate, severe, and fluctuating groups (P < 0.05). Patients with moderate-to-severe ACI accompanied by SDB are more likely to experience changes in circadian rhythm and sleep states, which in turn affect cognitive functions.

Restless leg syndrome (RLS) is characterized by unpleasant nocturnal sensations in the lower limbs, and it has emerged as the fourth leading cause of insomnia and is often an underdiagnosed medical condition among sleep disorders. The symptoms of RLS are more common in chronic kidney disease patients than in the general population. Therefore, we performed the first meta-analysis to estimate the risk of RLS among chronic kidney disease patients. We conducted a comprehensive search in Embase, Ovid-MEDLINE, PubMed, Scopus, Web of Science, and CINAHL databases. Data were analyzed with the random-effects model using Comprehensive Meta-Analysis (CMA) software to find the odds ratio (OR). The heterogeneity was checked with the I² test and Cochran’s Q-statistic, and we performed the moderator analysis to find potential sources of heterogeneity. The study quality was assessed using the Newcastle–Ottawa Scale. Of 1175 studies, we found nine studies, with a total of 18,983 participants. The pooled OR of RLS among chronic kidney disease was 5.64 (95%CI 2.70–11.78). Regarding moderator analysis results, it was observed that higher body mass index and abnormal laboratory results would increase the risk of RLS; however, the statistical test was not significant in the current study. The findings reveal a substantial sixfold increase in the likelihood of RLS when compared to the general population. Therefore, health professionals should encourage patients to adhere to the treatment and practice a healthy lifestyle to manage their condition and reduce the risk of RLS. Moreover, future research can develop an intervention to reduce RLS symptoms.

Abstract

The aim of this study was to assess age- and sex-related differences in multiple sleep latency test (MSLT) results and in the performance of the Epworth Sleepiness Scale (ESS) at classifying objective hypersomnia (mean sleep latency (MSL) ≤ 8 min). We studied 480 consecutive adults (39.3 ± 15.3 years old [18–93], 67.7% female) who underwent hypersomnia evaluation. We fit linear regression models to investigate associations between age and sex and sleep latencies (mean and for every nap), after adjusting for total sleep time and sleep efficiency (on polysomnography), and REM-suppressing antidepressant effect. A logistic regression was performed to assess whether age and sex were associated with sleep-onset REM period (SOREMP) occurrence. ROC analysis assessed the diagnostic performance of ESS scores to identify a MSL ≤ 8 min in different age/sex groups. For every 10 years of age, there was 0.41 (95% CI 0.11–0.72, p = 0.008) min reduction in MSL. Objectively (MSL ≤ 8 min) sleepy patients had shortening of latencies in naps 4 and 5 with aging. Female sex was associated with a higher MSL only in patients with MSL > 8 min. A 2.4% reduction in the odds of SOREMP occurrence was observed for every year of age in objectively sleepy patients (p = 0.045). ESS scores had a better diagnostic performance in older (≥ 50 years old) men than younger (< 50 years old) women (p < 0.05). Older patients with objectively confirmed hypersomnia may be sleepier in later naps, possibly due to less restorative naps and/or circadian rhythm factors. Self-reported sleepiness is more predictive of objective sleepiness in older men than younger women.

The aim was to investigate brain responses to non-painful tactile stimuli applied to the non-dominant hand during sleep. 21 healthy subjects participated in the study (11 female, mean age ± SD: 20.67 ± 1.91 years). A 40-channel polysomnography system and a pneumatic tactile stimulator unit were used. Stimuli were applied to the participants’ non-dominant hand. Evoked potential components of the C_Z electrode were examined in four sleep stages (N1, N2, N3, and REM). Repeated measures ANOVA was used in statistical analyses. Brain responses, categorized as early (P50, N100, and P200), mid-early (N300, P450, and N550), and late (P900 and Nlate), were detected all sleep stages. No notable variances were found in the amplitude and latency of early brain responses when analyzed across different sleep stages. Differences in both amplitude and latency were observed across different sleep stages for the N300, P450, P900, and Nlate response components. This study presents a pioneering exploration into the responses of the non-dominant hand throughout all sleep stages, encompassing eight distinct response components. This novel investigation contributes to the existing literature by shedding light on previously unexplored aspects. The observed early responses are identified as sensory, while middle to late responses align with cognitive processes within the realm of sleep research. Notably, N300, P450, P900, and Nlate components display variations across diverse sleep stages, marked by alterations in both amplitude and latency. These findings offer valuable insights into the dynamic nature of hand responses throughout the sleep continuum.

Sleep is important for good physical and mental health. The COVID-19 pandemic lockdown created a unique context that impacted psychological and social drivers for sleeping well. The Pittsburgh Sleep Quality Index (PSQI) is a widely used measurement tool assessing subjective sleep quality. The traditional model of the PSQI (a one-factor model), whilst validated and used across different populations, has also been questioned with regards to data fit and representativeness of its global score in different social and work-related circumstances. Examination of the structure validity of the PSQI in the unique context of the pandemic has been scarce. This study determined the PSQI structure validity amongst employed women considered to experience increased stressors during the pandemic lockdown. The subjectively reported PSQI data from 498 female workers (mean age 44.6 years) collected during New Zealand’s first national COVID-19 lockdown (April, 2020) was used. Confirmatory factor analyses compared the original one-factor model of the PSQI with the two- and three-factor models used by Jia et al. (2019) within this pandemic context. Results showed that the two-factor model provided a superior fit of the PSQI data compared to the original one-factor or a three-factor model. These findings suggest that a sub-score of the PSQI with two factors appears to be better at describing the sleep quality of healthy working women during the constrained situation of the pandemic lockdown compared to a single global sleep quality score. This indicates the importance of considering the validity of subjective sleep measures when used within unique social contexts and stressors.

Abstract

Bedtime procrastination (BP) is prevalent and problematic, with no previous study conducted in Japan. This study developed the Japanese version of the Bedtime Procrastination Scale (BPS), assessed its validity, and investigated the relationship between BP, demographic features, and sleep outcomes. Participants were divided into two samples (N = 252 and N = 630). Sample 1 involved a longitudinal study to confirm test–retest reliability of the BPS. Sample 2 involved a cross-sectional study to assess confirmatory factor analysis, criterion-related validity, construct validity, and determine the internal consistency of the BPS. The relationship between BP and demographic features (gender, age, and employment status) and sleep outcomes (Athens Insomnia Scale, sleep hours, sleep onset latency, and sleep efficiency) was investigated using Sample 2. The BPS showed good internal consistency (Cronbach’s α coefficients = .90–91), test–retest reliability (ICC = .86), and one factor model was valid; CFI = .95, TLI = .94, RMSEA = .10, and SRMR = .04. The BPS had a moderate positive association with general procrastination, moderate negative associations with self-control, sleep quality, and sleep duration on weekdays, and those who answered “yes” to the item “Do you have trouble with bedtime procrastination?” had higher BPS scores. BPS scores were moderately higher for younger participants (≤ 40 years), slightly higher for females, and non-significantly different between employment statuses. The BPS showed a significant positive correlation with insomnia symptoms, weak positive association with sleep efficiency on weekdays and holidays, and no significant association with sleep onset latencies on holidays and weekdays. This study provides new data on demographic predictors of BP in Japan. No clear effects of gender and employment status were found, but age was a strong predictor of BP, where younger age groups had a higher BP risk.