Changes In Sleep Duration Research Articles

0644 Longitudinal sleep instability contributes to cognitive decline and Alzheimer’s pathology: Findings from the Seattle Longitudinal Study

Abstract Introduction Although emerging data suggest a link between sleep duration, aging, and dementia diagnosis, the impact of longitudinal patterns of sleep behavior on Alzheimer’s disease-associated pathology and cognitive decline remains unclear. Methods Utilizing longitudinal data on self-reported sleep duration collected within the Seattle Longitudinal Study (n=535 subjects, age 75.18 +/- 11.6 years), we first used a Cox proportional hazard (CPH) regression model to evaluate the overall effect of mean sleep duration, longitudinal changes in sleep duration, and variability in sleep duration on the development of cognitive decline, including APOE4 genotype, sex, years of education, and depression as covariates within the model. In a secondary study, within the subset of subjects for whom postmortem histopathological assessment has been conducted (n=105 subjects, age 86.6 +/- 8.0 years), we used supervised machine learning to predict Alzheimer’s pathology, measured by CERAD neuritic plaque score and Braak stage. Results Multivariable CPH regression analysis demonstrated that there was a significant association between cognitive decline risk and APOE status (hazard ratio 2.28, 95% CI 1.41-3.69, p<0.005), depression (hazard ratio 1.09, 95% CI 1.04-1.14, p<0.005), sleep stability (hazard ratio 2.78, 95% CI 1.43-5.43, p<0.005), and sleep restlessness (hazard ratio 0.70, 95% CI 0.51-0.97, p<0.03). Notably, sleep variability across time and not median sleep duration was significantly associated with cognitive impairment. Adding these sleep parameters to the model improved model performance (base model concordance = 0.66, model including sleep = 0.72). Sleep parameters also improved performance on models predicting Alzheimer’s disease-associated pathology. Conclusion While these findings support a mixed effect of sleep duration on cognitive decline and the development of Alzheimer’s-associated neuropathology, they further suggest that variability in longitudinal sleep duration may exert a previously unappreciated influence on these pathological processes. Future studies should seek to replicate these findings in an independent cohort and to assess whether sleep variability of different time scales (weeks, years, decades) exerts similar effects on these outcomes. Support (If Any)

Objectively Assessed Habitual Sleep Duration Is Associated with Peripheral and Central Blood Pressure in Non‐Hypertensive Young Adults

Habitual short sleep duration (<6 hrs/night) has been reliably shown to predict higher blood pressure (BP) and hypertension in adults. However, most studies evaluating this association in free‐living adults (i.e., non‐experimental settings) have: 1. relied on subjective sleep duration estimates or actigraphy‐derived estimates spanning ≤7 days; 2. failed to consider central BP, which has been reported to provide greater insight into future cardiovascular risk as compared to peripheral BP; and 3. neglected to consider the influence of sleep duration the night prior to BP evaluation despite evidence that episodes of acute sleep loss (e.g., experimentally shortened sleep duration) increases peripheral BP values in young adults. Therefore, the purpose of the present study was to investigate the association between objectively measured habitual sleep duration (HSD) with peripheral and central BP in non‐hypertensive, non‐shift working, apparently healthy, young adults free of sleep disorders. This study also examined whether changes in sleep duration the night before BP measurement (ΔSD) influenced these relationships. We hypothesized that shorter HSD would significantly predict higher peripheral and central BP values, but that the association would be weakened after adjusting for ΔSD the night before assessment. Sleep duration (the total time scored as sleep between sleep onset and offset) was measured via wrist‐worn actigraphy for 14 consecutive nights (days 1‐14) and mean HSD was generated. Additionally, ΔSD was calculated as the difference between sleep duration the night before testing (day 14) and mean sleep duration across days 1‐13. On the morning following the final night of sleep monitoring (day 15), resting supine peripheral BP was measured, and central BP was estimated using pulse wave analysis. BP measures included systolic BP (SBP), diastolic BP (DBP), and mean arterial pressure (MAP). The associations between HSD and peripheral and central BP values were evaluated using linear regression models of BP values. Regression models were further adjusted for ΔSD to determine whether this influenced these associations. The analytic sample consisted of 28 participants (11M/17F; 27±7 yrs). Mean HSD for the sample was 6.91±0.74 hours per night. ΔSD sleep was ‐25±53 minutes, indicating that on average, sleep duration was shorter the night before testing. Shorter mean HSD significantly predicted both higher peripheral BP (SPB: β= ‐6.44, SE= 2.11, p< 0.01; DBP: β= ‐5.03, SE= 1.63, p< 0.01; MAP: β= ‐5.42, SE= 1.63, p< 0.01) and higher central BP (cSBP: β= ‐5.79, SE= 2.00, p< 0.01; cDBP: β= ‐5.06, SE= 1.59, p< 0.01; cMAP: β= ‐5.45, SE= 1.74, p< 0.01) values. When models were adjusted for ΔSD, HSD remained a significant predictor of peripheral BP (SPB: β= ‐5.45, SE= 2.06, p= 0.01; DBP: β= ‐4.50, SE= 1.66, p= 0.01; MAP: β= ‐4.71, SE= 1.60, p= 0.01) and central BP (cSBP: β= ‐4.91, SE= 2.00, p= 0.02; cDBP: β= ‐4.57, SE= 1.62, p= 0.01; cMAP: β= ‐4.81, SE= 1.75, p= 0.01). Our findings support prior evidence that HSD plays a key role in peripheral BP regulation and newly demonstrate that HSD is also significantly inversely associated with central BP values. Acute alterations in sleep duration the night prior to BP evaluation has a minimal influence on the association between HSD and BP in young, otherwise healthy free‐living adults.

Temporal changes in self-reported sleep quality, sleep duration and sleep medication use in relation to temporal changes in quality of life and work ability over a 1-year period among Finnish municipal employees.

In this prospective follow-up study, we aimed to examine whether changes in self-reported sleep quality, sleep duration, and sleep medication use are temporally associated with changes in quality of life and work ability in municipal employees when several confounding factors are considered. The study was conducted in Finland among 637 municipal employees (88% women, mean [SD] age 48[10]years) in 2014 and 2015. Information about the participants was collected by self-administered questionnaire and from medical history. Predicting variables were changes in self-reported sleep quality, sleep duration, and sleep medication use. Outcome variables were changes in the EUROHIS-QOL eight-item index and the Work Ability Score. Improved or unchanged sleep quality compared to worse sleep quality were associated with a preferable change in quality of life (both p < 0.001). No change in sleep duration compared to a decrease and no change in sleep medication use compared to increased use were also associated with favourable changes in quality of life. Increased use of sleep medication was associated with a decline in work ability, and the change in Work Ability Score also differed significantly between improved and worsened sleep quality. In this study, changes in sleep were widely associated with changes in quality of life and work ability of municipal employees. Programmes aiming for better sleep health would probably be beneficial both from a health-oriented and an economical point of view. Special attention should be paid to employees with a need for sleep medication.

Is Icelanders' sleep duration getting shorter? Review on sleep duration and sleeping habits

Sleep health promotion is an ever-increasing subject of public discourse in Iceland. Prominent claims made include that the duration of sleep among Icelanders is shortening, and that changing sleeping habits constitute a significant public health risk. Like many aspects of healthcare, commercial interests and sales hype can skew perception. This review article will seek to shed light on the scientific background of these statements. International meta-analysis suggests there has been little change in sleep duration in adults over the past century. The duration of childrens sleep has shortened, but the consequences of this are not yet well established. Significant shortening of the sleep of adult Icelanders has not been demonstrated. No difference in sleep duration is found between Icelandic adults and adolescents and comparable groups in neighboring countries. The measurement methods that are used when comparing sleep studies are variable and can lead to different results. Associations have been established between sleep duration and adverse health outcomes, both physical and mental, but causality has not yet been established, and potential important mediators of the relationships are discussed. The circadian sleep phase of Icelanders is generally delayed relative to neighbors, likely related to Iceland's diurnal length variation at sub-Arctic latitudes and longitudinal discrepancies between natural light and local time.

Abstract MP55: Declining Annual Trends In Us Daily Sleep Duration Are Greater Among Racial/ethnic Minorities: Implications For Cardiometabolic Disease Disparities

Introduction: Habitual insufficient sleep may contribute to cardiometabolic disease in the United States, particularly among racial and ethnic minorities. However, there is mixed evidence on secular trends in U.S. sleep duration. Therefore, this study investigated annual changes in sleep duration, including variations across demographics and how sleep duration was associated with prevalent cardiometabolic disease. Methods: Data on 413,417 individuals were acquired from the National Health Interview Survey from 2005-2018. Variables included self-reported sleep duration, lifetime diagnosis of hypertension, coronary heart disease, diabetes, and pre-diabetes, and obesity. Population-weighted linear models estimated annual trends in sleep duration, while population-weighted quasi-Poisson models estimated the prevalence risk of cardiometabolic disease as a function of sleep duration. Results: Average daily sleep duration decreased -0.62 minutes annually from 2005-2018. A significant race/ethnicity interaction was found. Compared to Non-Hispanic Whites, the rate of decline was 119% greater among Blacks/African-Americans, 206% greater among Mexican-Americans, 4% greater in other Hispanics/Latinos, and 43% greater in Asians. A 1-hour loss in daily sleep duration was linked to 4% greater prevalence of hypertension, 3% greater prevalence of diabetes, and 8% greater prevalence of obesity after adjusting for age, sex, employment, marital status, and survey year. A significant race/ethnicity interaction was observed, with differential elevated risk of cardiometabolic risk factor prevalence associated with declining sleep (see table). Conclusion: There is a secular decline in U.S. daily sleep duration that is disproportionately impacting Black/African-American and Mexican individuals. Moreover, reduced sleep duration is associated with more prevalent cardiometabolic disease and these relationships are disproportionately impacting racial/ethnic minority groups.

Preliminary Effectiveness Study of a Community-Based Wellness Coaching for Cancer Survivors Program.

Substantial cancer burden may be prevented through lifestyle modifications. The purpose of this study was to determine the preliminary effectiveness of health coaching for the improvement of health, fitness, and overall well-being of cancer survivors in a community setting. Participants were recruited from Cancer Support Community Delaware locations. Health coaching was provided to people diagnosed with cancer anywhere along the survivorship continuum. Coaches provided 6 individual sessions. Surveys were sent pre- and post-intervention on topics including fitness, eating habits, sleep, perceived stress, anxiety, depression, and quality of life. Results were analyzed using multilevel modeling. 48 participants completed an average of 85% of health coaching sessions. Coaching participants noted improvements in weekly physical activity frequency, including moderate-vigorous physical activity. Increases were found in healthy eating behavior. Participants reported improvements in the quality of their sleep, including changes in sleep duration and sleep efficiency. Significant reductions were found in perceived stress, anxiety, and depression. Importantly, participants reported improved quality of life, particularly in areas of physical and emotional well-being, as well as functional and total well-being. Preliminary findings indicate significant behavior change in measured outcomes and suggest health coaching may be an important tool for cancer survivorship.

Effect of Sleep Extension on Objectively Assessed Energy Intake Among Adults With Overweight in Real-life Settings

Short sleep duration has been recognized as a risk factor for obesity. Whether extending sleep duration may mitigate this risk remains unknown. To determine the effects of a sleep extension intervention on objectively assessed energy intake, energy expenditure, and body weight in real-life settings among adults with overweight who habitually curtailed their sleep duration. This single-center, randomized clinical trial was conducted from November 1, 2014, to October 30, 2020. Participants were adults aged 21 to 40 years with a body mass index (calculated as weight in kilograms divided by height in meters squared) between 25.0 and 29.9 and had habitual sleep duration of less than 6.5 hours per night. Data were analyzed according to the intention-to-treat principle. After a 2-week habitual sleep period at baseline, participants were randomized to either an individualized sleep hygiene counseling session that was intended to extend their bedtime to 8.5 hours (sleep extension group) or to continue their habitual sleep (control group). All participants were instructed to continue daily routine activities at home without any prescribed diet or physical activity. The primary outcome was change in energy intake from baseline, which was objectively assessed as the sum of total energy expenditure and change in body energy stores. Total energy expenditure was measured by the doubly labeled water method. Change in body energy stores was computed using regression of daily home weights and body composition changes from dual-energy x-ray absorptiometry. Sleep duration was monitored by actigraphy. Changes from baseline were compared between the 2 groups using intention-to-treat analysis. Data from 80 randomized participants (mean [SD] age, 29.8 [5.1] years; 41 men [51.3%]) were analyzed. Sleep duration was increased by approximately 1.2 hours per night (95% CI, 1.0 to 1.4 hours; P < .001) in the sleep extension group vs the control group. The sleep extension group had a significant decrease in energy intake compared with the control group (-270 kcal/d; 95% CI, -393 to -147 kcal/d; P < .001). The change in sleep duration was inversely correlated with the change in energy intake (r = -0.41; 95% CI, -0.59 to -0.20; P < .001). No significant treatment effect in total energy expenditure was found, resulting in weight reduction in the sleep extension group vs the control group. This trial found that sleep extension reduced energy intake and resulted in a negative energy balance in real-life settings among adults with overweight who habitually curtailed their sleep duration. Improving and maintaining healthy sleep duration over longer periods could be part of obesity prevention and weight loss programs. ClinicalTrials.gov Identifier: NCT02253368.

The freshman sleep and health (FRoSH) study: Examining sleep and weight gain in incoming college freshmen

Objective Examine how changes in sleep duration, objectively measured by activity trackers, impact weight gain in incoming college freshman. Participants: Incoming college freshmen, age ≥ 18. Methods: We measured weight and daily sleep duration before college entry and through the 1st college quarter. Additionally, we examined changes in sleep variability, activity levels and smartphone screen time use as possible predictors of weight gain. Results: 75 participants completed the study. Total sleep duration decreased from 437.9 ± SD 57.3 minutes at baseline to 416.5 ± SD 68.6 minutes by the end of the first quarter (p = 6.6 × 10−3). (BMI) did not change significantly in this cohort. Higher sleep variability at baseline and an increase in sleep variability were associated with increases in BMI. Smartphone screen use was note to be high (235.2 ± SD 110.3 minutes/day) at the end of the first quarter. Conclusions: College weight gain may be affected by factors other than sleep duration, including sleep variability. Supplemental data for this article can be accessed online at https://doi.org/10.1080/07448481.2022.2032720

Changes in Smoking Behavior, Stress, and Sleep Duration Among Israeli Hospital Workers During the COVID-19 Pandemic: A Cross-sectional Study.

IntroductionBeing on the COVID-19 frontline could negatively impact healthcare workers mental health.Aims and MethodsWe examined smoking behavior changes and the association with changes in stress levels and sleeping patterns among hospital workers during the pandemic. An online survey was conducted among employees of a large tertiary medical center in Israel. Data collected included sociodemographic characteristics, smoking status, changes in smoking behavior (for smokers only), stress levels, and sleeping duration during the pandemic, perceptions of risk for COVID-19 infection and disease severity, presence of a chronic illness, COVID-19 exposure and infection status, and involvement in treating COVID-19 patients. Multinominal logistic regression modeling assessed the effects of covariates on smoking behavior change.ResultsOverall, 920 healthcare workers participated. More than half (59%) reported an increase in stress and 28% reported changes in sleep duration. Thirty-five percent of current smokers (n = 132), reported smoking more. Increased stress was associated with an increase in smoking (odds ratio [OR] = 3.45, 95% confidence interval [CI] 1.2–9.4, p = .016), and an increase in sleeping hours was significantly associated with a decrease in smoking (OR = 6.42, 95% CI 1.2–32, p = .02). Among smokers who reported perceived levels of stress to be the same or slightly higher than prepandemic, a strong inverse association was observed between sleep and smoking.ConclusionsThe mental health consequences of the pandemic, specifically for health workers, could lead to negative changes in smoking behaviors. Together with offering stress-management skills and coping strategies, mental health support should target smoking behaviors and sleep disturbances.ImplicationsA high proportion of healthcare employees working in a large tertiary medical center in Israel reported increased stress levels during the COVID-19 pandemic. Among smokers, increased stress levels were associated with increased smoking, suggesting that smoking may be a coping mechanism for COVID-19-related stress. Offering stress-management skills and coping strategies can mitigate the negative impact on health workers’ smoking behavior, and reduce stress-related increases in smoking behavior.

Decrease in Sleep Duration and Poor Sleep Quality over Time Is Associated with an Increased Risk of Incident Non-Alcoholic Fatty Liver Disease.

The impact of changes in sleep duration and sleep quality over time on the risk of non-alcoholic fatty liver disease (NAFLD) is not known. We investigated whether changes in sleep duration and in sleep quality between baseline and follow-up are associated with the risk of developing incident NAFLD. The cohort study included 86,530 Korean adults without NAFLD and with a low fibrosis score at baseline. The median follow-up was 3.6 years. Sleep duration and quality were assessed using the Pittsburgh Sleep Quality Index. Hepatic steatosis (HS) and liver fibrosis were assessed using ultrasonography and the fibrosis-4 index (FIB-4). Cox proportional hazard models were used to determine hazard ratios (HRs) and 95% confidence intervals (Cis). A total of 12,127 subjects with incident HS and 559 with incident HS plus intermediate/high FIB-4 was identified. Comparing the decrease in sleep duration of >1 h, with stable sleep duration, the multivariate-adjusted HR (95% CIs) for incident HS was 1.24 (1.15–1.35). The corresponding HRs for incident HS plus intermediate/high FIB-4 was 1.58 (1.10–2.29). Comparing persistently poor sleep quality with persistently good sleep quality, the multivariate-adjusted HR for incident HS was 1.13 (95% CI, 1.05–1.20). A decrease in sleep duration or poor sleep quality over time was associated with an increased risk of incident NAFLD, underscoring an important potential role for good sleep in preventing NAFLD risk.

Biology vs. ecology: a longitudinal examination of sleep, development, and a change in school start times

BackgroundSecondary school start times are associated with student sleep and daytime functioning; however, no study examining this association has included linked longitudinal data for both primary and secondary students. To understand the interplay between biology (ie, normal developmental changes in sleep) and ecology (ie, school start times), this study examined sleep and daytime functioning in elementary/primary and secondary school students over a three-year period that included changes to school start times. MethodsStudents (grades 3–10, n = 6168) and parents (for student grades Kindergarten-2, n = 2772) completed annual surveys before (pre-change) and for two-years after (post-change, follow-up) implementation of new school start times (elementary/primary: 60 min earlier, secondary: 50–80 min later). Participants were 48.9% female, 65.5% White, and 16.2% qualified for free/reduced lunch. ResultsWith new school start times, significant changes were found for weekday wake times and sleep duration; elementary/primary students woke earlier (23 min) and obtained less sleep (14 min), while secondary students woke later (44 min) and obtained more sleep (31 min). Small changes in weekend sleep duration (<7 min) were found across levels. Secondary school students had significant improvements in daytime functioning post-change, due in part to changes in sleep duration. Minimal changes in elementary/primary students’ daytime functioning was found, despite shorter sleep duration. ConclusionsSchool start times are a significant factor in weekday wake times for students across grade levels, while later bedtimes are more a factor of normal development. Later start times positively affected secondary students’ daytime functioning, with non-significant findings for earlier elementary/primary start times.

Socioeconomic inequality in compliance with precautions and health behavior changes during the COVID-19 outbreak: an analysis of the Korean Community Health Survey 2020.

OBJECTIVESThis study examined socioeconomic inequalities in compliance with precautions and health behavior changes during the coronavirus disease 2019 (COVID-19) outbreak using a representative Korean sample.METHODSThis exploratory study utilized around 210,000 participants aged ≥25 years in the Korean Community Health Survey 2020. Socioeconomic status was measured with educational attainment and household income. Outcomes included non-compliance with 8 precaution measures and deterioration in 6 health behaviors. The relative inequality index (RII) was calculated to quantify the degree of inequality by education and income level. RII values >1.0 indicate that deprived people have a higher frequency of health problems, and RII values <1.0 conversely indicate a higher frequency of health problems in more advantaged groups.RESULTSPeople with lower education or income levels tended to have higher rates of non-compliance with COVID-19 safety precautions (RII range, 1.20 to 3.05). Lower education and income levels were associated with an increased smoking amount (RII=2.10 and 1.67, respectively) and sleep duration changes (RII=1.21 and 1.36, respectively). On the contrary, higher education and income levels were associated with decreased physical activity (RII=0.59 and 0.77, respectively) and increased delivery food consumption (RII=0.27 and 0.37, respectively). However, increased alcohol drinking was associated with lower education and income levels in younger men (RII=1.73 and 1.31, respectively), but with higher levels in younger women (RII=0.73 and 0.68, respectively).CONCLUSIONSOur findings suggest the need to develop customized strategies, considering the characteristics of the target population, to decrease the burden and impact of the COVID-19 outbreak.

Changes in Sleep Duration and the Risk of Cognitive Impairment Among Older Adults Aged 65 Years and Over — China, 2014–2019

<abstract abstract-type="Summary"> <sec> <b>What is already known about this topic?</b> Earlier studies indicated that shorter or excessive sleep duration at baseline was related to cognitive impairment. Yet few studies have been concerned with the association between sleep duration changes and cognitive performance, especially in low- and middle- income countries. </sec><sec> <b>What is added by this report?</b> A prospective cohort study suggests that maintaining moderate sleep duration may lead to optimal cognitive performance. Either decreasing, increasing, or keeping a longer sleep duration is associated with the risk of cognitive impairment among Chinese elderly aged 65 years and over. </sec><sec> <b>What are the implications for public health practice?</b> Maintaining a moderate sleep duration may be a protective factor against cognitive impairment. Therefore, we need to pay attention to the seniors' sleep health and prevent or delay the progression of cognitive impairment through sleep therapy. </sec>

Behavioral Measures in Myopic and Non-myopic High Schoolers During the COVID Pandemic

Purpose: The purpose of this study is to understand how the visual activity of highschool students in Houston changed due to quarantine and online learning during the COVID-19 pandemic, and whether these behaviors were different between myopes and non-myopes.&#x0D; Methods: Thirty-one participants (16.3±0.8 years, 8 females), including 12 myopes and 8 non-myopes, wore a Clouclip and Actiwatch for a week. The Clouclip records working distance and the Actiwatch measures light exposure, physical activity, and sleep duration. A questionnaire was also completed regarding demographics, ocular history, and visual behaviors.&#x0D; Results: Data showed that myopic participants engaged in near work (working distances of 10 to &lt;60 cm) for 8.4±2.6 hours on a week day and 6.5±2.1 hours on a weekend day. Non-myopic participants engaged in near work for 6.1±2.7 hours on a week day and 4.5±1.9 hours on a weekend day. While weekend near work was significantly different between refractive error groups (P&lt;.05), weekday near work (P=.08) was not. There were no differences between refractive error groups for daily light exposure (P = .89), time outdoors (P = .44), or sleep duration (P = .80).&#x0D; Conclusions: There was no significant change in sleep duration and physical activity regardless of refractive error over the pandemic, while results revealed a significant decrease in outdoor light exposure and the increase in near and intermediate work, especially with electronic devices such as the computer.

Links of Sleep Duration with Biomarkers of Accelerated Aging: the Baltimore Longitudinal Study of Aging

Sleep disorders and sleep deprivation have been linked to markers of biological aging, including methylation change and increases in white blood cell and neutrophil counts. However, little is known regarding the association of sleep duration with biological markers of aging. We investigated links of self-reported sleep duration with biological aging markers in 615 participants in the Baltimore Longitudinal Study of Aging (BLSA) aged ≥50 years (mean = 71.0 ± 11.2, 49.6% women, 68.8% white) with data on self-reported sleep duration in hours (i.e., ≤6 (n=131), >6 to 7 (n=234), >7 (n=250)), demographics, and genetic and methylation data (mDNA). Our aging biomarker outcomes were four epigenetic clocks (Horvath, Hannum, PhenoAge, and GrimAge), mDNA-estimated PAI1, and estimated granulocyte count. After adjustment for age, sex, and race, compared to those sleeping ≤6 hours, those reporting >7 hours of sleep had faster biological aging according to Hannum age-acceleration, PhenoAge, GrimAge, mDNA-estimated PAI1, and granulocyte count. In addition, sleep duration interacted with age, such that compared to individuals reporting ≤6 hours of sleep, individuals reporting >6 to 7 hours showed lower GrimAge with increasing age, and with sex, such that males with longer sleep duration (>6 to 7 and >7 hours) showed a lower granulocyte count compared to females. Findings suggest that both short and long sleep duration are associated with and may contribute to accelerated aging. Prospective studies in larger samples are needed to examine whether changes in sleep duration precede changes in aging biomarkers.

CLOCK Genetic Variations Are Associated With Age-Related Changes in Sleep Duration and Brain Volume.

Although a connection between sleep disruption and brain aging has been documented, biological mechanisms need to be further clarified. Intriguingly, aging is associated with circadian rhythm and/or sleep dysfunction in a key gene regulating circadian rhythm, Circadian Locomotor Output Cycles Kaput (CLOCK), has been linked to both aging-related sleep disturbances and neurodegenerative diseases. This study aims to investigate how CLOCK genetic variation associates with sleep duration changes and/or volumetric brain alteration. This population-based cross-sectional study used data from the Korean Genome Epidemiology Study and analyzed sleep characteristics and genetic and brain imaging data in 2 221 participants (mean 58.8 ± 6.8 years, 50.2% male). Eleven single-nucleotide polymorphisms (SNPs) in CLOCK were analyzed using PLINK software v1.09 to test for their association with sleep duration and brain volume. Haplotype analysis was performed by using pair-wise linkage disequilibrium of CLOCK polymorphisms, and multivariate analysis of covariance was for statistical analysis. Decreased sleep duration was associated with several SNPs in CLOCK intronic regions, with the highest significance for rs10002541 (p = 1.58 × 10-5). Five SNPs with the highest significance (rs10002541, rs6850524, rs4580704, rs3805151, rs3749474) revealed that CGTCT was the most prevalent. In the major CGTCT haplotype, decreased sleep duration over time was associated with lower cortical volumes predominantly in frontal and parietal regions. Less common haplotypes (GCCTC/CGTTC) had shorter sleep duration and more decreases in sleep duration over 8 years, which revealed smaller total and gray matter volumes, especially in frontal and temporal regions of the left hemisphere. CLOCK genetic variations could be involved in age-related sleep and brain volume changes.

Both increased and decreased sleep duration over time are associated with subsequent cancer development.

Changes in sleep duration have been reported to correlate with lifestyle-related diseases in humans. However, equivalent studies regarding the effects of sleep on cancer progression are lacking. This study aimed to determine whetheror not increase or decrease in sleep duration over time is associated with subsequent cancer development. A large-scale, retrospective cohort study wasconducted at a preventive medicine health center at a general community hospital in Tokyo, Japan. All participants who underwent health checkups at the hospital between January 2005 and December 2018 were included. The primary study outcome was development of any type of cancer according to the slope of sleep duration over the study period. The Cox proportional hazard model was used to adjust the outcomes based on potential covariates. Of 15,025 participants, 7,692 (51.2%) were men. The mean age (standard deviation) was 66.0 (7.5) years. During a median follow-up of 2,588 (interquartile range: 1,583-3,695) days, 1,396 (9.3%) participants developed cancer of any type. Compared to hazard ratio in the stable sleep duration group (- 0.1 to + 0.1h/day in 1year), both greatly decreased (less than - 0.2h/day in 1year; hazard ratio (HR), 2.13; 95% confidence interval (CI), 1.72-2.62) and increased (more than + 0.2h/day in 1year; HR, 2.55; 95% CI 2.14-3.04) groups showed significantly higher hazard ratio for the development of any type of cancer. Both increased and decreased sleep duration over time are associated with subsequent cancer development.

Relationship of sleep duration and annual changes in sleep duration with the incidence of gastrointestinal cancers: a prospective cohort study.

Background:Prospective analyses have yet to identify a consistent relationship between sleep duration and the incidence of gastrointestinal (GI) cancers. The effect of changes in sleep duration on GI cancer incidence has scarcely been studied. Therefore, we aimed to examine the association between baseline sleep duration and annual changes in sleep duration and GI cancer risk in a large population-based cohort study.Methods:A total of 123,495 participants with baseline information and 83,511 participants with annual changes in sleep duration information were prospectively observed from 2006 to 2015 for cancer incidence. Cox proportional-hazards models were used to calculate hazard ratios (HRs) and their confidence intervals (CIs) for GI cancers according to sleep duration and annual changes in sleep duration.Results:In baseline sleep duration analyses, short sleep duration (≤5 h) was significantly associated with a lower risk of GI cancer in females (HR: 0.31, 95% CI: 0.10–0.90), and a linear relationship between baseline sleep duration and GI cancer was observed (P = 0.010), especially in males and in the >50-year-old group. In the annual changes in sleep duration analyses, with stable category (0 to −15 min/year) as the control group, decreased sleep duration (≤−15 min/year) was significantly associated with the development of GI cancer (HR: 1.29; 95% CI: 1.04–1.61), especially in the >50-year-old group (HR: 1.32; 95% CI: 1.01–1.71), and increased sleep duration (>0 min/year) was significantly associated with GI cancer in females (HR: 2.89; 95% CI: 1.14–7.30).Conclusions:Both sleep duration and annual changes in sleep duration were associated with the incidence of GI cancer.

Basketball-Specific Small-Sided Games Training during Ramadan Intermitting Fasting: Do Changes in Body Composition, Sleep Habits, and Perceived Exertion Affect Technical Performance?

The objective of this study was to assess the effects of an additional small-sided games (SSGs) training program during Ramadan intermitting fasting (RIF) on technical performance depending on changes in body composition, sleep habits, and ratings of perceived exertion (RPE). Twenty-four professional male basketball players from the Tunisian first division participated in this study. The players were randomly assigned to an intervention group (INT; n = 12) or an active control group (CON; n = 12). Both groups completed a four-week SSG training program (three sessions per week). During the first and fourth weeks of the SSGs training, the two groups were evaluated to detect changes in technical performance, dietary intake, body composition, sleep quality index (PSQI) survey outcomes, RPE, heart rate (HR), and blood lactate concentration [La]. During the fourth week of the RIF period, body composition, dietary intake, sleep latency, sleep duration, and HR significantly decreased only for INT (p < 0.001). However, RPE significantly increased (p < 0.001), and technical performances were negatively affected (p < 0.01). MANCOVA (adjusted for the percentage of change in sleep duration, body mass, and RPE) showed no significant differences in either group. In conclusion, our results showed that the technical performance of professional basketball male players was significantly affected at the end of RIF independently of changes in RPE, sleep habits, and body composition.

The links between sleep duration, obesity and type 2 diabetes mellitus.

Global rates of obesity and type 2 diabetes mellitus (T2DM) are increasing globally concomitant with a rising prevalence of sleep deprivation and sleep disorders. Understanding the links between sleep, obesity and T2DM might offer an opportunity to develop better prevention and treatment strategies for these epidemics. Experimental studies have shown that sleep restriction is associated with changes in energy homeostasis, insulin resistance and β-cell function. Epidemiological cohort studies established short sleep duration as a risk factor for developing obesity and T2DM. In addition, small studies suggested that short sleep duration was associated with less weight loss following lifestyle interventions or bariatric surgery. In this article, we review the epidemiological evidence linking sleep duration to obesity and T2DM and plausible mechanisms. In addition, we review the impact of changes in sleep duration on obesity and T2DM.