Sleep and Biological Rhythms最新文献

Circular RNAs (circRNAs) participate in diverse biological processes. However, whether circRNAs exhibit distinct expression patterns under obstructive sleep apnea (OSA)-induced chronic intermittent hypoxia (CIH) remains unexplored. We conducted RNA sequencing to compare expression profiles between CIH rats (n = 4) and normoxic controls (n = 4), identifying differentially expressed (DE) circRNAs. After filtering candidate circRNAs, we validated their expression in four OSA patients and four controls using qRT-PCR. Principal component analysis (PCA) was employed to confirm the diagnostic potential of these circRNAs. The miRanda software predicted target microRNAs (miRNAs), and the circRNA-miRNA regulatory network was visualized using Cytoscape software. In total, we identified 43 DE circRNAs, primarily enriched in functions like protein binding, cytoskeleton organization, and supramolecular complexes. We selected eight DE circRNAs associated with CIH for validation in OSA patients (n = 4) and controls (n = 4), with five displaying significant expression differences. These eight circRNAs showed distinct expression patterns between CIH and control groups, suggesting potential utility in distinguishing CIH conditions. Notably, our analysis identified mir-466b-3p as associated with DE circRNAs in the context of CIH. In conclusion, this study described circRNA expression profiles in CIH rats and identified several circRNAs with altered expression in CIH conditions. These findings suggest areas for further research into the relationship between circRNA expression and CIH.

Supplementary information: The online version contains supplementary material available at 10.1007/s41105-025-00577-w.

The pineal gland releases melatonin to regulate our body's circadian rhythm based on light and dark cycles. The pinealectomy (PINX) model is an experimental approach employed to investigate the potential impact of melatonin on various tissues and pathologies. In this study, acetylcholinesterase (AChE) enzyme activity levels, oxidative stress parameters, histopathological findings, and serum melatonin levels in rat brain tissue were evaluated following pinealectomy. 24 male Sprague Dawley rats were randomly divided into groups: control, Sham-Pinealectomy (SHAM), and PINX. Brain tissue samples were taken at the end of a 50-day experimental period to determine the parameters of AChE, glutathione s-transferase (GST), carboxylesterase (Ces) enzyme activities, and malondialdehyde (MDA), reduced glutathione (GSH) levels spectrophotometrically. Moreover, serum melatonin levels were measured, and tissues underwent standard histological analysis to determine the histopathological damage score. In this study, we found that the PINX group had decreased AChE and Ces enzyme activity, increased MDA, decreased GSH levels, and no change in GST enzyme activity. A relative decrease in serum melatonin levels was also observed in the PINX group. In the light microscopic examination of the brain tissue of pinealectomy rats, it was observed that the eosinophilic staining intensity increased, heterochromatic/pycnotic-looking neuron nuclei were prominent in the cortex layers and hippocampus, and perineural edematous areas were abundant. Excessive perineuronal edema, cytoplasmic eosinophilia, and heterochromatic/pycnotic nuclei were found based on the histopathological damage score. After pinealectomy, we observed an increase in oxidative stress and a decrease in AChE levels in the brain.

To compare pain characteristics, functional limitation, psychosocial factors, and sociodemographic characteristics between patients with chronic LBP reporting good or poor sleep quality. A secondary analysis of 444 patients with a current episode of chronic low back pain (CLBP). Sleep quality was measured by an item of the Pittsburgh Sleep Quality Index (PSQI). Pain intensity (two items from The Brief Pain Inventory, BPI), functional limitation (The Patient-Specific Functional Scale, PSFS, and BPI), and psychosocial factors (The Brief Screening Questions, BSQ) were also assessed. Features of participants with good and poor sleep quality were compared. Participants were classified as "good sleep quality" (n = 228) or "poor sleep quality" (n = 216). Those with poor sleep quality showed greater functional limitations (Good sleepers = 5.38 ± 2.54; Poor sleepers = 6.48 ± 2.35; p < 0.01), higher pain interference with functionality (Good sleepers = 35.90 ± 23.87; Poor sleepers = 50.84 ± 26.89; p < 0.01), and more significant psychosocial issues, such as anxiety [Good sleepers = 165 (37%); Poor sleepers = 186 (42%); p < 0.01], and depressive symptoms [Good sleepers = 37 (8%); Poor sleepers = 73 (16%); p < 0.01]. Chronic LBP patients with poor sleep quality significantly faced more functional limitation, increased pain interference, and a higher prevalence of psychological problems, including anxiety and depression, than those with good sleep quality. Our results emphasize the impact of poor sleep quality in clinical measures of LBP patients.

To investigate differences in polysomnography (PSG) parameters and heart rate variability (HRV) during the initial 3-h sleep period in patients with mild, moderate, and severe obstructive sleep apnea syndrome (OSA). According to the apnea-hypopnea index, patients were divided into 3 groups: mild, moderate, and severe (n = 23, 59, and 94, respectively). PSG was performed, and HRV (frequency domain analysis), sleep stage (S1, S2, S3, REM, and waking), and sleep fragmentation index (SFI) were measured during the initial 3-h sleep periods. The total S1 time was significantly longer in the severe group than in the mild and moderate groups (p < 0.001). The severe group had significantly shorter total S2 and S3 times than the mild (p = 0.014, p < 0.001) and moderate (p = 0.034, p = 0.029) groups did. The SFI was significantly greater in the severe group than in the mild and moderate groups (p < 0.001, p = 0.008). The high-frequency component (HF) of the HRV showed no significant differences except that it was significantly smaller during S3 in the moderate group than in the mild group (p = 0.026). Compared with those with mild/moderate status, patients with severe OSA have shallower sleep and a higher SFI, suggesting poorer sleep quality. Although HF during S3 was significantly smaller in the moderate group, it did not significantly differ between the mild and severe groups, suggesting that the parasympathetic nervous system might compensate for humoral and hypoxemic abnormalities in patients with severe OSA.

OSA is defined as the repeated occurrence of apnea or hypopnea during sleep caused by upper airway collapse. Obstructive sleep apnea (OSA) is characterized by a high apnea-hypopnea index (AHI) and persistent daytime sleepiness. Body roundness index (BRI), calculated using waist circumference and height, is a measure of obesity. BRI demonstrates a stronger correlation with body fat compared to BMI. However, no studies have thus far reported on the association between BRI and OSA. The data for this study were sourced from the National Health and Nutrition Examination Survey (NHANES) database (2005-2008 and 2015-2018). BRI was computed as 364.2-365.5 * (1 - [WC(m)/2π]²/[0.5 * height(m)]²)^½. Statistical methods for data analysis included multivariable logistic regression, trend tests, restricted cubic spline (RCS) plots, subgroup analysis, and interaction tests, with a significance level of p < 0.05. This cross-sectional study investigated the relationship between BRI and OSA in 8106 American adults. After adjusting for all considered covariates, BRI was found to be positively associated with the risk of OSA, with each 1-unit increase in BRI raising the risk of OSA by 167% (95% CI [2.42, 2.95], p < 0.001). The positive association between BRI and OSA was consistent across all subgroups (p < 0.001). The restricted cubic spline (RCS) plot further confirmed the positive correlation between BRI and OSA prevalence (p value < 0.0001, p nonlinear < 0.0001). The results of this study demonstrate a positive correlation between BRI and OSA, suggesting that BRI could be utilized as a predictive factor for OSA. BRI could assist clinicians in the diagnosis of OSA in patients.

Supplementary information: The online version contains supplementary material available at 10.1007/s41105-024-00566-5.

The aim of this study was to investigate the sleep structure of mid-day naps in students who frequently nap, and to determine whether this structure has any impact on their subjective feelings after nap. A total of 91 college students (male, mean age 20.47 ± 2.02 years) completed one-hour mid-day nap with polysomnographic recording in a sleep laboratory. Upon awakening, self-ratings of sleep quality and sleepiness were assessed using questionnaires. The sleep structure of mid-day naps varied among participants: 47.3% participants experienced stage-1, -2, and -3 non-rapid eye movement (NREM) sleep in sequence in the one-hour nap, while rapid eye movement (REM) sleep occurred between 40 and 60 min after lights off in 27.5% participants, and less than 15 min in 16.5% participants. After nap, participants who achieved stage-3 sleep reported better sleep quality, but the subjective sleepiness was not influenced by the sleep stage contained in nap or the sleep stage at awakening. These findings highlight the diversity in the sleep structure of mid-day naps, suggesting that this variability may need to be considered when studying the effects of napping.