Sleep Research Articles

Melatonin, Melatonin Receptors and Sleep: Moving Beyond Traditional Views.

Sleep, constituting approximately one-third of the human lifespan, is a crucial physiological process essential for physical and mental well-being. Normal sleep consists of an orderly progression through wakefulness, non-rapid eye movement (NREM) sleep, and rapid eye movement (REM) sleep, all of which are tightly regulated. Melatonin, often referred to as the "hormone of sleep," plays a pivotal role as a regulator of the sleep/wake cycle and exerts its effects through high-affinity G-protein coupled receptors known as MT1 and MT2. Selective modulation of these receptors presents a promising therapeutic avenue for sleep disorders. This review examines research on the multifaceted role of melatonin in sleep regulation, focusing on selective ligands targeting MT1 and MT2 receptors, as well as studies involving MT1 and MT2 knockout mice. Contrary to common beliefs, growing evidence suggests that melatonin, through MT1 and MT2 receptors, might not only influence circadian aspects of sleep but likely, also modulate the homeostatic process of sleep and sleep architecture, or could be the molecule linking the homeostatic and circadian regulation of sleep. Furthermore, the distinct brain localization of MT1 and MT2 receptors, with MT1 receptors primarily regulating REM sleep and MT2 receptors regulating NREM sleep, is discussed. Collectively, sleep regulation extends beyond the circulating levels and circadian peak of melatonin; it also critically involves the expression, molecular activation, and regulatory functions of MT1 and MT2 receptors across various brain regions and nuclei involved in the regulation of sleep. This research underscores the importance of ongoing investigation into the selective roles of MT1 and MT2 receptors in sleep. Such research efforts are expected to pave the way for the development of targeted MT1 or MT2 receptors ligands, thereby optimizing therapeutic interventions for sleep disorders.

AAV8-P301L tau expression confers age-related disruptions in sleep quantity and timing

Sleep timing and quantity disturbances persist in tauopathy patients. This has been studied in transgenic models of primary tau neuropathology using traditional electroencephalograms (EEGs) and more recently, the PiezoSleep Mouse Behavioral Tracking System. Here, we generated a primary tauopathy model using an intracerebroventricular injection of human mutant hSyn-P301L-tau, using adeno-associated virus of serotype 8 (AAV8). We discovered distinctions in sleep architecture with altered quantity and timing in AAV8-P301L tau expressing mice of both sexes using the noninvasive PiezoSleep System. The AAV8-P301L tau mice exhibit striking age-related increases in sleep duration specifically at the active phase onset, suggesting a critical and sensitive time-of-day for tauopathy related sleep disturbances to occur. Since our findings show sleep behavior changes at specific transitional periods of the day, tau neuropathology may impact normal diurnal variation in biological processes, which should be explored using the AAV8-P301L tauopathy model.

Exploring Arterial Health, Perceived Stress And Sleep Patterns In Adolescents

Exploring Arterial Health, Perceived Stress And Sleep Patterns In Adolescents

Differences In Sleep Patterns Between College Varsity Athletes And Non-athlete Controls Disappear In Midlife

Differences In Sleep Patterns Between College Varsity Athletes And Non-athlete Controls Disappear In Midlife

Targeting retrieval of methamphetamine reward memory in the context of REM sleep deprivation: Age-dependent role of GABAB receptors

GABAB receptors play a modulatory role in the mechanisms underlying drug addiction, sleep problems, and aging; however, there are few studies addressing their relationship. Therefore, this study aimed to examine whether blockade of these receptors affects methamphetamine (METH) reward memory in adult and adolescent rapid-eye movement sleep deprived (RSD) rats. Adolescent and adult male Wistar rats were subjected to RSD for seven days. They were then conditioned to receive methamphetamine (METH; 2 mg/kg, ip) during an eight-day conditioning period. METH reward memory was then reactivated during a retrieval trial and the GABAB receptor agonist baclofen (2.5 or 5 mg/kg, ip) was injected prior to the retrieval trial. Afterward, animals were retested for the expression of conditioned place preference (CPP) and hippocampal expression of GABAB receptors. Baclofen dose-dependently decreased the retrieval of METH reward memory in control and RSD adult and adolescent rats, but its effects were stronger at the higher dose. Moreover, we found stronger effects of baclofen in adolescent animals than in adult ones. In addition, baclofen at its higher dose decreased GABAB overexpression in the hippocampus of adolescent rats, but not in adult rats. These findings shed new light on the mechanisms underlying the role of GABAB receptors in the retrieval of METH reward memory and highlight the importance of considering age and sleep patterns in understanding addiction. Further research could potentially lead to the development of therapeutics for individuals struggling with METH addiction.

Prevalence of Substance Use Among Students in Health Colleges in Saudi Arabia: A Cross-Sectional Study.

Substance misuse is a global and substantial health concern that includes the inappropriate use of illicit substances or prescription and over-the-counter medications, which subsequently leads to poor outcomes such as a mental health disorder, financial distress, work malfunction, and academic failure. This study aimed to assess the prevalence of substance use, identify associated risk factors, explore potential complications within this specific demographic, and investigate the relationship between sociodemographic/lifestyle variables such as age, gender, marital status, family income, smoking, physical activity, and academic variables including grade point averages (GPAs), study hours, and the parental educational level with substance use history among students in health colleges in Saudi Arabia. This quantitative, descriptive cross-sectional study employed a questionnaire-based approach to collect data from students in health colleges across the regions of Saudi Arabia in the year 2022. The study found the prevalence of the use of various substances among students in health colleges to be 20.2%. Multiple factors were found to be associated with substance abuse. Smoking habits were the strongest predictor of substance misuse, with 49.1% of smokers reporting a history of substance use, compared to only 15.5% of non-smokers. This makes smoking the most impactful lifestyle factor related to substance use. Sleep patterns also played a significant role. A notable 43.6% of those who took up to two hours to fall asleep reported substance use, followed by 32.4% of those with sleep disorders and 25.5% with poor sleep quality. Unpredictable sleep patterns and a history of sleep disorders further strengthened the link between disrupted sleep and substance misuse. Academic performance, specifically GPA, showed that individuals with lower academic achievement were more likely to report substance use. Among those with a GPA below 3.0, 43.5% had a history of substance use, while only 16.7% of those with a GPA above 4.5 did so. The findings underscored the high prevalence of substance use, even among students in health colleges, and shed light on its connection to specific determinants. This poses a serious public health concern, as substance use is associated with poorer GPA, diminished knowledge acquisition, and overall academic performance. This, in turn, may negatively impact their future roles as healthcare providers, compromising both the quality of patient care and their personal well-being. These results emphasize the need for further investigations to unravel the underlying mechanisms of substance misuse and formulate innovative strategies to address this pressing issue effectively.

Ambient Air Pollutant Mixture, Sleep Pattern, and Incident CKD: Results from a Prospective Cohort Study

Ambient Air Pollutant Mixture, Sleep Pattern, and Incident CKD: Results from a Prospective Cohort Study

The Impact of Social Media Usage on Mental Health Among College Students: Patterns, Psychological Effects, and Implications for Well-being

This study explores the impact of social media usage on the mental health of college students, focusing on usage patterns and psychological effects. A descriptive research design was employed, with a sample size of 121 respondents selected through stratified random sampling. Data was gathered using a closed-ended questionnaire featuring a 5-point Likert scale. The findings reveal that social media consumption varies significantly among students, with a majority experiencing mood changes and potential addiction. Furthermore, the analysis highlights the influence of social media on daily activities, sleep patterns, and overall mental well-being. The study provides valuable insights into the relationship between social media usage and mental health, offering a foundation for future research on mitigating negative psychological impacts among students.

Sleep patterns and quality during summer and academic year among female university students.

To measure sleep patterns and quality during summer vacation and weeks 1-4 of the academic year among female university students. This retrospective prospective cohort study included female students at a university in Riyadh, Saudi Arabia. Participants were recruited with convenience sampling and completed questionnaires online. The questionnaire asked about 5 occasions using the Sleep Quality Scale (SQS) and about their sleep schedule during summer vacation and weeks 1-4 of the academic year. There were 385 participants. The number of students who slept before midnight increased over time from n=127 (32.9%) students during vacation to n=172 (44.6%) students in week 4 (p<0.001). The average sleep hours decreased from 8.97 (standard deviation (SD)=2.6) hours during summer to 7.01 (p<0.001, SD=2.7) hours in week 4. Students reported poorer sleep quality during the academic year, particularly in week 1 (p=0.023), than summer. Students reported higher satisfaction with sleep during summer vacation (n=97; 25.2%) than week 1 (n=38; 9.9%) and week 4 (n=36; 9.4%) (p<0.001). Students experienced daytime fatigue and tiredness (n=79; 20.5%; p=0.002) and low concentration in week 4 (n=79; 20.5%; p<0.001) compared to summer. In the studied population, multiple sclerosis was the most prevalent cause of ON. Women were more likely to have ON. The prognosis for eyesight was substantially connected with the length of ON.

24-hour Patterns Of Physical Activity, Sedentary Behavior, And Sleep During A University Program For Faculty And Staff

24-hour Patterns Of Physical Activity, Sedentary Behavior, And Sleep During A University Program For Faculty And Staff

Can Neuromodulation Improve Sleep and Psychiatric Symptoms?

In this review, we evaluate recent studies that employ neuromodulation, in the form of non-invasive brain stimulation, to improve sleep in both healthy participants, and patients with psychiatric disorders. We review studies using transcranial electrical stimulation, transcranial magnetic stimulation, and closed-loop auditory stimulation, and consider both subjective and objective measures of sleep improvement. Neuromodulation can alter neuronal activity underlying sleep. However, few studies utilizing neuromodulation report improvements in objective measures of sleep. Enhancements in subjective measures of sleep quality are replicable, however, many studies conducted in this field suffer from methodological limitations, and the placebo effect is robust. Currently, evidence that neuromodulation can effectively enhance sleep is lacking. For the field to advance, methodological issues must be resolved, and the full range of objective measures of sleep architecture, alongside subjective measures of sleep quality, must be reported. Additionally, validation of effective modulation of neuronal activity should be done with neuroimaging.

Bidirectional Interaction of Sepsis and Sleep Disorders: The Underlying Mechanisms and Clinical Implications.

Sepsis is defined as life-threatening organ injury induced by infection, with high incidence and mortality. Sleep disorder is prevalent in septic patients and approximately 50% of patients with sepsis may develop atypical sleep patterns, but many of them may have been underdiagnosed by physicians. Sleep disorders and sepsis exhibit a close bidirectional relationship, with each condition significantly influencing the other. Conversely, sleep deprivation, sleep dysrhythmia and sleep fragmentation have been shown to impact the outcome of sepsis. This review endeavors to offer a comprehensive understanding of the intricate mechanisms that underpin the interplay between sepsis and sleep disorders, in addition to exploring potential clinical intervention strategies that could enhance outcomes for patients suffering from sepsis.

Characterizing Sleep Patterns And The Validity Of Wearable Sleep Metrics In First-year College Students

Characterizing Sleep Patterns And The Validity Of Wearable Sleep Metrics In First-year College Students

Training Practices And Sleep Patterns Of Athletes During Ramadan Fasting: An International Survey

Training Practices And Sleep Patterns Of Athletes During Ramadan Fasting: An International Survey

The Impact of Supervised and Home Exercise Activity Intervention on Circulating Immune Cell Numbers in Cancer Patients.

IntroductionMalignant diseases challenge clinicians to balance treatment intensity and patient quality of life. Regular physical activity positively impacts mental and physical health, benefiting sleep patterns, heart rate, and overall health. Moreover, telehealth physical exercise training represents a viable option for maintaining intrinsic capacity. The American Cancer Society highlights exercise's role in helping patients cope with anti-cancer treatment side effects. In the Czech Republic, there is no fitness-promoting protocol for cancer patients, despite recognized benefits. Exercise may also enhance immune function, with moderate-intensity exercise potentially positively affecting immune cell counts. ObjectiveThis study aimed to analyze the long-term effects of exercise on circulating immune cells in patients undergoing treatment for solid malignancies. Patients and Methods49 participants were recruited at the Masaryk Memorial Cancer Institute, Czech Republic, starting September 2021. Participants were randomized into an experimental (SAPA = undergoing monitored exercise program) group (N = 16; madian age: 46,6; median BMI: 25,1) and a control (CO) group (N = 33; madian age: 52,0; median BMI: 25,3). Flow cytometry was used to examine cellular immunological profiles. The exercise program involved thrice-weekly sessions conducted online. ResultsSAPA group showed stable lymphocyte counts post-exercise (percentage chance: +0,5%; p = 0,256; effect size r = −0,284), while the CO group exhibited a significant drop (percentage chance: −23,0%; p = 0,015; effect size r = −0,423). B lymphocyte numbers were significantly higher in the SAPA group post-exercise compared to the CO group (p = 0,003; effect size r = −0,422). The number of Th-lymphocytes, T-c lymphocytes, T-gamma/delta lymphocytes, and NK cells remained stable in SAPA but dropped in CO group. ConclusionExercise's impact on the immune system in cancer patients shows promise, with differences noted between acute and chronic exercise effects. Previous studies on acute exercise indicate a rise in immune cell counts, supporting our findings of stable or increased immune cells with controlled exercise in cancer patients. Controlled physical activity stabilizes or increases certain immune cell populations in patients undergoing chemotherapy for solid malignancies, highlighting the potential benefits of incorporating exercise into cancer treatment protocols.

Sleep Disturbances in Health Professional Students During the COVID-19 Pandemic: A Concept Analysis.

The aim is to delineate the concept of sleep disturbances in health professional students during the COVID-19 pandemic. A concept analysis was conducted. A systematic search was conducted for relevant articles published and performed from inception to July 5, 2024. Electronic databases searched included PubMed, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Embase and Web of Science. Rodgers' method of evolutionary concept analysis was used. A total of 50 pertinent articles were included in our analysis. Utilising inductive thematic analysis, this study identified attributes, antecedents and consequences of sleep disturbances. Important attributes included insomnia, disrupted sleep patterns, altered sleep duration/nocturnal sleep duration and poor sleep quality. Antecedents encompassed factors such as gender, age/grade levels, physical activity, screen time of digital production, mental health issues, COVID-19-related stressors, financial strain and academic stress. Consequences included both mental and physical health implications. By addressing sleep disturbances and promoting better sleep health among students, we can enhance their learning and performance, which could translate to improved patient care outcomes. Additionally, understanding and mitigating sleep disturbances can contribute to the development of a more resilient and effective health care workforce, capable of providing high-quality care even during crises like the COVID-19 pandemic. No patient or public contribution.

Measuring Conditional Anonymity - A Global Study

The realm of digital health is experiencing a global surge, with mobile applications extending their reach into various facets of daily life. From tracking daily eating habits and vital functions to monitoring sleep patterns and even the menstrual cycle, these apps have become ubiquitous in their pursuit of comprehensive health insights. Many of these apps collect sensitive data and promise users to protect their privacy - often through pseudonymization. We analyze the real anonymity that users can expect by this approach and report on our findings. More concretely: We introduce the notion of conditional anonymity sets derived from statistical properties of the population; We measure anonymity sets for two real-world applications and present overarching findings from 39 countries; We develop a graphical tool for people to explore their own anonymity set. One of our case studies is a popular app for tracking the menstruation cycle. Our findings for this app show that, despite their promise to protect privacy, the collected data can be used to identify users up to groups of 5 people in 97% of all the US counties, allowing the de-anonymization of the individuals. Given that the US Supreme Court recently overturned abortion rights, the possibility of determining individuals is a calamity.

Sleep, Well-Being, and Cognition in Medical Interns on a Float or Overnight Call Schedule

Extended work hours and night shifts are essential in health care, but negatively affect physician sleep, well-being, and patient care. Alternative schedules with shorter work hours and/or reduced irregularity might mitigate these issues. To compare sleep, well-being, and cognition between interns working irregular, extended shifts (call schedule), and those working a more regular schedule with restricted hours (float schedule). In this observational longitudinal cohort study, interns in a Singapore-based teaching hospital were studied for 8 weeks from January 2022 to July 2023. Data were analyzed from July 2023 to July 2024. Participants worked either regular approximately 10-hour workdays, interspersed with 24 hour or more overnight calls 4 to 5 times a month, or a float schedule, which included regular approximately 10-hour workdays, and 5 to 7 consecutive approximately 12-hour night shifts every 2 months. Exposure was based on departmental training and operational needs. Sleep was measured with wearable sleep trackers and an electronic diary. Day-to-day well-being and cognitive assessments were collected through a smartphone application. Assessments included the Sleep Regularity Index (SRI; determines the probability of an individual being in the same state [sleep or wake] at any 2 time points 24 hours apart, with 0 indicating highly random sleep patterns and 100 denoting perfect regularity) and Pittsburgh Sleep Quality Inventory (PSQI; scores ranges from 0 to 21, with higher scores indicating poorer sleep; a score greater than 5 suggests significant sleep difficulties). Participants (mean [SD] age, 24.7 [1.1] years; 57 female participants [59.4%]; 41 on call schedule [42.7%]; 55 on float schedule [57.3%]) provided 4808 nights of sleep (84.2%) and 3390 days (59.3%) of well-being and cognition assessments. Participants on a float schedule had higher SRI scores (mean [SD] score, 69.4 [6.16]) and had better quality sleep (PSQI mean [SD] score, 5.4 [2.3]), than participants on call schedules (SRI mean [SD] score, 56.1 [11.3]; t91 = 6.81; mean difference, 13.3; 95% CI, 9.40 to 17.22; P < .001; PSQI mean [SD] score, 6.5 [2.3]; t79 = 2.16; 95% CI, 0.09 to 2.15; P = .03). Overnight call shifts, but not night float shifts, were associated with poorer mood (-13%; β = -6.79; 95% CI, -9.32 to -4.27; P < .001), motivation (-21%; β = -10.09; 95% CI, -12.55 to -7.63; P < .001), and sleepiness ratings (29%; β = 15.96; 95% CI, 13.01 to 18.90; P < .001) and impaired vigilance (21 ms slower; β = 20.68; 95% CI, 15.89 to 25.47; P < .001) compared with regular day shifts. Night shifts with naps were associated with better vigilance (16 ms faster; β = -15.72; 95% CI, -28.27 to -3.17; P = .01) than nights without naps. In this cohort study, 24-hour call schedules were associated with poorer sleep, well-being, and cognition outcomes than float schedules. Naps during night shifts benefited vigilance in both schedules.

Prospective crossover trial of positional and CPAP therapy for the treatment of mild-to-moderate positional obstructive sleep apnea.

To evaluate efficacy of vibrotactile positional therapy (PT) compared to standard CPAP therapy in mild-to-moderate positional obstructive sleep apnea (pOSA). Prospective crossover randomized controlled trial of adult patients with treatment-naïve, symptomatic, mild-to-moderate pOSA - defined as ≥5 total apnea-hypopnea index (AHI) <30 with supine-to-non-supine (s:ns)AHI ratio ≥2. Participants were randomized to in-laboratory treatment initiation polysomnography with either PT or CPAP on sequential nights before an eight-week trial of each therapy. The primary endpoint was symptomatic improvement (Epworth Sleepiness Scale; ΔESS). Secondary endpoints included patient preference, usage, sleep architecture and quality of life (QoL) measures. 52 participants were enrolled and completed both arms of the study. Participants were symptomatic with median ESS 12 (IQR 10-14). Treatment resulted in a significant (p<0.001) symptomatic improvement with both PT and CPAP (ΔESS 4; IQR 6-11) without a significant difference between treatment arms (p=0.782). PT was effective at restricting supine sleep and demonstrated improved sleep efficiency compared with CPAP, although no better than baseline. Both therapies were effective at reducing AHI, although CPAP demonstrated superior AHI reduction. There were otherwise no clinically significant differences in sleep architecture, usage, or secondary outcomes including overall patient preference. In this cohort, treatment with PT or CPAP resulted in clinically significant symptomatic improvement (ΔESS) that was not significantly different between treatment arms. No real difference was seen in other secondary outcome measures. This study provides further evidence to support the use of PT as an alternative first-line therapy with CPAP in appropriately selected patients with pOSA. Registry: Australian New Zealand Clinic Trials Registry; Name: Prospective crossover trial of Positional and Continuous positive airway pressure Therapy for the treatment of mild-to-moderate positional obstructive sleep apnoea; Identifier: ACTRN12619000475145; URL: https://anzctr.org.au/Trial/Registration/TrialReview.aspx?id=377221&isReview=true.

The association between salivary IL-6 and poor sleep quality assessed using Apple watches in stressed workers in Japan.

Insomnia is a major concern among stressed workers worldwide. Although stress generally has a detrimental effect on sleep quality, the impact of biological stress, especially the immunological stress response, on sleep quality is not yet fully understood. Stressed workers were recruited through a screening process using a Brief Job Stress Questionnaire. The participants were asked to complete various occupation-related questionnaires. Additionally, saliva samples were collected to assess interleukin-6 (IL-6) levels as an immunological stress response. Subsequently, they were asked to wear an Apple Watch to record their sleep pattern for one week. Their sleep architecture was estimated using a previously published and validated method. Finally, data from 73 participants were analyzed. Our multivariable analysis revealed that shorter durations of slow-wave sleep (non-rapid eye movement sleep stage 3) were significantly associated with elevated IL-6 levels (p = 0.005) and greater daytime sleepiness (p = 0.002) after controlling for total sleep time. Our finding that a higher immunological stress response is associated with poor sleep quality contributes to a better understanding of insomnia in stressed workers and emphasizes the importance of stress management in this population.