Short Sleep Duration Research Articles

A cross-sectional study on the relationship between infant sleep, temperament and bedtime practices.

To explore the interplay between infant temperament, sleep characteristics, and bedtime practices. We conducted a cross-sectional study involving a large sample of 9-13 month old infants (N = 623). Sleep data were collected through auto-videosomnography, allowing for objective, non-invasive assessment of sleep in an infants' ecological environment. Infant temperament and bedtime practices were assessed with questionnaires completed by parents. Results revealed significant correlations between negative affectivity and disrupted sleep patterns, including shorter sleep duration, more night awakenings, and increased parental interventions. Infants falling asleep while being breast/bottle feeding or while being hold/rocked had shorter nocturnal sleep duration, lower sleep efficiency, later bedtime, earlier wake up time, and more parent interventions. Regression analyses indicated that bedtime practices accounted for a substantial portion of variance in sleep metrics, emphasizing their role in influencing infant sleep. The study highlights the intricate interconnections between infant temperament, sleep, and caregiving practices, emphasizing the need for a nuanced understanding of individual differences to tailor effective parenting strategies for promoting healthy sleep in infants.

Sleep Behavior in Royal Australian Navy Shift Workers by Shift and Exposure to the SleepTank App.

Rotating shiftwork schedules are known to disrupt sleep in a manner that can negatively impact safety. Consumer sleep technologies (CSTs) may be a useful tool for sleep tracking, but the standard feedback provided by CSTs may not be salient to shift-working populations. SleepTank is an app that uses the total sleep time data scored by a CST to compute a percentage that equates hours of sleep to the fuel in a car and warns the user to sleep when the "tank" is low. Royal Australian Navy aircraft maintenance workers operating on a novel rotational shift schedule were given Fitbit Versa 2s to assess sleep timing, duration, and efficiency across a 10-week period. Half of the participants had access to just the Fitbit app while the other half had access to Fitbit and the SleepTank app. The goal of this study was to evaluate differences in sleep behavior between shifts using an off-the-shelf CST and to investigate the potential of the SleepTank app to increase sleep duration during the 10-week rotational shift work schedule. Royal Australian Navy volunteers agreed to wear a Fitbit Versa 2 with the SleepTank app (SleepTank condition), or without the SleepTank app (Controls), for up to 10 weeks from May to July 2023 during the trial of a novel shift rotation schedule. Participants from across 6 units worked a combination of early (6:00 AM to 2:00 PM), day (7:30 AM to 4:30 PM), late (4:00 PM to 12:00 AM), and night shifts (12:00 AM to 6:00 AM) or stable day shifts (6:00 AM to 4:00 PM). Differences in sleep behavior (time in bed, total sleep time, bedtime, wake time, sleep efficiency [SE]) between conditions and shift types were tested using Analysis of Variance. This study was approved by the Australian Departments of Defence and Veterans' Affairs Human Research Ethics Committee. Thirty-four participants completed the full study (n = 17 Controls; n = 17 SleepTank). There was a significant effect of shift type on 24-hour time in bed (TIB24; F(4,9) = 8.15, P < .001, η2 = 0.15) and total sleep time (TST24; F(4,9) = 8.54, P < .001, η2 = 0.18); both were shorter in early shifts and night shifts compared to other shift types. TIB24 and TST24 were not significantly different between conditions, but there was a trend for greater SE in the SleepTank condition relative to Controls (F(1,9) = 2.99, P = .08, η2 = 0.11). Sleep data collected by Fitbit Versa 2s indicated shorter sleep duration (TIB24, TST24) for Royal Australian Navy workers during early and late shifts relative to stable day shifts. Access to the SleepTank app did not greatly influence measures of sleep duration but may be protective against fatigue by affecting SE. Further research is needed to evaluate the utility of the SleepTank app as a means of improving sleep hygiene in real-world, shift-working environments.

Germ aversion is a risk factor for chronic low back pain and shoulder pain under the COVID-19 pandemic: an internet-based panel study

The COVID-19 pandemic has increased germ aversion, an aversive affective response to a high likelihood of pathogen transmission. While psychological factors are associated with chronic pain, the relationship between germ aversion and chronic pain remains unexplored. This study aimed to examine the relationship between germ aversion and new-onset and prognosis of chronic pain using longitudinal data collected during the COVID-19 pandemic. We conducted web-based surveys of full-time workers at baseline and after three months. Data were collected on demographic characteristics, psychological factors, and chronic pain. Germ aversion was assessed using a modified Perceived Vulnerability to Disease scale. We analyzed responses from 1265 panelists who completed the survey twice. The prevalence of chronic low back pain (CLBP) and chronic neck and shoulder pain (CNSP) was associated with sex, short sleep duration, psychological distress, loneliness, and germ aversion. Stratified analyses showed that germ aversion was a risk factor for CLBP at three months in both individuals with and without CLBP at baseline, and for CNSP at three months in those with CNSP at baseline, even after adjustment for confounders. In conclusion, this preliminary study suggests that high germ aversion is a risk factor for CLBP and CNSP in young and middle-aged workers.

Combined effects of sleep timing and nighttime sleep duration on non-alcoholic fatty liver disease

BackgroundWhile short sleep duration is linked to higher risk of non-alcoholic fatty liver disease (NAFLD), the combined effects of sleep timing and sleep duration on NAFLD are less explored. MethodsIn this cross-sectional study of 39,471 participants from Beijing-Tianjin-Hebei region of China, self-reported sleep information and ultrasonography-diagnosed NAFLD were obtained from Jan 2018 to Jan 2020. Sleep timing was categorized based on sleep midpoint: early-type (before 2:00 AM), intermediate-type (2:00–2:30 AM), and late-type (after 2:30 AM). We used multivariable logistic regression to explore the relationship between sleep timing, duration, and NAFLD. We analyzed sleep midpoint and duration categorically and continuously, and conducted stratification analyses by age, sex, body mass index, hypertension, diabetes, and dyslipidemia. ResultsIntermediate-type (OR: 1.15, 95% confidence interval: 1.05–1.26) and late-type sleep timing (OR: 1.08, 1.00–1.16) were associated with higher NAFLD risk compared to early-type. Additionally, longer sleep duration was linked to lower risk (OR: 0.92, 0.90–0.95 per hour increase). Notably, intermediate to late-type sleepers with normal sleep duration (7 to <8 h) exhibited a 20% higher NAFLD risk compared to early-type sleepers with the same duration (OR: 1.20, 1.04–1.39). The increased NAFLD risk associated with intermediate to late sleep timing was particularly evident in men, hypertension, and prediabetes or diabetes participants. ConclusionsIntermediate to late sleep timing, even with normal sleep duration, is associated with increased NAFLD risk. These findings underscore the importance of considering both sleep timing and sleep duration for NAFLD prevention, especially in men and individuals with cardiometabolic conditions.

Association of habitual sleep duration with abnormal bowel symptoms: a cross-sectional study of the 2005–2010 national health and nutrition examination survey

ObjectivesNowadays, few studies have examined the relationships between sleep duration and abnormal gut health. In this study, we used data from the National Health and Nutrition Examination Survey (NHANES) to investigate the correlations between habitual sleep duration and abnormal bowel symptoms in adults.MethodsThis study included 11,533 participants aged ≥ 20 years from the NHANES conducted during 2005–2010. Chronic constipation and chronic diarrhea were defined based on the Bristol Stool Form Scale (BSFS) and frequency of bowel movements. Sleep duration was assessed based on the self-report questionnaire and classified into three groups: short sleep duration (< 7 h), normal sleep duration (7–9 h), and long sleep duration (> 9 h). Weighted data were calculated according to analytical guidelines. Logistic regression models and restricted cubic spline curves (RCS) were used to assess and describe the association between sleep duration and chronic diarrhea and constipation. Univariate and stratified analyses were also performed.ResultsThere were 949 (7.27%) adults aged 20 years and older with chronic diarrhea and 1120 (8.94%) adults with constipation among the 11,533 individuals. A positive association was found between short sleep duration and chronic constipation, with a multivariate-adjusted OR of 1.32 (95% CI: 1.05–1.66). Additionally, long sleep duration was significantly associated with an increased risk of chronic diarrhea (OR: 1.75, 95% CI: 1.08–2.84, P = 0.026). The RCS models revealed a statistically significant nonlinear association (P for non-linearity < 0.05) between sleep duration and chronic diarrhea. Furthermore, obesity was found to modify the association between sleep duration and chronic diarrhea and constipation (p for interaction = 0.044).ConclusionsThis study suggests that both long and short sleep durations are associated with a higher risk of chronic diarrhea and constipation in the general population. Furthermore, a non-linear association between sleep duration and these conditions persists even after adjusting for case complexities.

Sleep duration in middle-aged years of life predicts the age of diagnosis of Parkinson's disease

IntroductionChronic short sleep duration (i.e., <7 h sleep daily) could reduce the brain's ability to attenuate toxin and protein accumulation, which may contribute to Parkinson's disease (PD). The purpose of this study was to characterize the relationship between self-reported sleep duration from adolescence to adulthood and the age of diagnosis in people with PD. A secondary purpose was to characterize the interaction between sleep duration and physical activity through the lifespan on the age of PD diagnosis. MethodsA secondary data analysis was performed using the Fox Insight data set. Multiple regression analysis was used to determine the age range that sleep duration best predicted the age of diagnosis of PD. Hierarchical linear multiple regression was performed to assess if self-reported sleep duration, physical activity, and their interaction predicted the age of diagnosis for PD, after accounting for sociodemographic factors. ResultsBoth sleep (p < 0.001) and physical activity time (p = 0.013) significantly predicted the of age of onset of PD. In contrast, there was no evidence to support an interaction of sleep by physical activity on the age of diagnosis of PD. Sleep duration at 46–55 years maintained significance after controlling for education, income, race, ethnicity, and sex (p < 0.001). Weekly duration of time spent performing moderate-intensity physical activity was added as an input variable. ConclusionSleep duration significantly predicts the age of diagnosis of PD, with shorter sleep duration associated with a younger age of diagnosis of PD.

Sleep Duration, Insomnia, and Associated Factors Among Ukrainians 1 Year After Russia's Full-Scale Invasion.

We aimed to investigate the prevalence of sleep disturbances and associated factors among Ukrainians 1 year after Russia's full-scale invasion. Quota sampling was used to collect online survey data from 2364 adults living in Ukraine aged 18 to 79 years from April 5, 2023, to May 15, 2023. Short sleep duration was defined as sleep duration ≤6 hours and long sleep duration as ≥9 hours. Insomnia was assessed by the Insomnia Symptom Questionnaire. The prevalences of short sleep duration, long sleep duration, and insomnia were 39.4%, 6.9%, and 38.5%, respectively. Short sleep duration and insomnia were both more likely in females (short sleep duration: adjusted odds ratio [aOR] = 1.44; insomnia: aOR = 2.17), individuals with depression (short sleep duration: aOR = 1.61; insomnia: aOR = 7.76), affected by the 2014 Russian invasion (short sleep duration: aOR = 1.37; insomnia: aOR = 1.78), and with more trauma events (short sleep duration: quartile 3 [Q3] versus Q1: aOR = 1.88; Q4 versus Q1: aOR = 1.83; insomnia: Q3 versus Q1: aOR = 2.14; Q4 versus Q1: aOR = 2.32). Insomnia was more likely in Ukrainians with posttraumatic stress disorder (aOR = 2.95), anxiety (aOR = 4.57), and loneliness (aOR = 1.67). Essential public service was associated with short sleep duration (aOR = 1.64). Short sleep duration and insomnia were associated with lower quality of life in physical, psychological, and environmental domains. Insomnia was associated with the social relationships domain. Sleep health among Ukrainian adults 1 year into the war is concerning, with more than one-third reporting inadequate sleep or insomnia. More studies are needed on impacts and interventions for sleep health during and after the war.

Insomnia and sleep duration for kidney function: Mendelian randomization study

Objectives Extensive researches highlight the detrimental impact of sleep disorders such as insomnia and insufficient sleep duration on kidney function. However, establishing a clear causal relationship between insomnia, sleep duration, and kidney function remains challenging. This study aims to estimate this relationship using Mendelian randomization (MR). Methods Independent genetic variants strongly associated with insomnia (N = 462,341) and sleep duration (N = 460,099) were selected as instrumental variables from corresponding genome-wide association studies (GWAS). Kidney function parameters, including serum creatinine, estimated glomerular filtration rate by cystatin C (eGFRcys), acute renal failure (ARF), chronic renal failure (CRF), kidney injury molecule-1, neutrophil gelatinase associated lipocalin, microalbuminuria, cystatin C, and β2 microglobulin, were derived from GWAS databases. A two-sample MR study was conducted to assess the causal relationship between sleep disorders and kidney function, and multivariable MR was used to identify potential mediators. The inverse-variance weighted was used as the primary estimate. Results MR analysis found robust evidence indicating that insomnia and short sleep duration were associated with an increased risk of elevated serum creatinine, regardless of adjusting for obesity. Causal links between sleep duration and eGFRcys or cystatin C were also identified. While genetically predicted insomnia and sleep duration were found to potentially impact ARF, CRF, microalbuminuria, and β2 microglobulin, the p-values in multivariable MR analysis became nonsignificant. No pleiotropy was detected. Conclusions This study demonstrates a causal impact of insomnia on the risk of elevated serum creatinine and a positive effect of sleep duration on serum creatinine, eGFRcys, and cystatin C. Our findings also suggest their potential indirect effects on ARF, CRF, microalbuminuria, and β2 microglobulin mediated by obesity.

The association between sleep, mental health, and health behaviours: a Danish population-based cross-sectional study.

Sleep problems constitute a significant public health problem due to their high prevalence and impact on mental health and health behaviours, with major consequences for individuals and society. Therefore, the aim of this study was to investigate the association between sleep problems (duration and quality), mental health and health behaviours. Cross-sectional data was derived from the 2021 health survey 'How are you?' from the Central Denmark Region. The study population was a stratified random sample of 33,925 respondents aged 16 years or older. We used logistic regression models to analyse the associations between sleep problems and indicators of mental health and health behaviour. The models were adjusted for sex, age, educational attainment, labour market attachment, cohabitation, and indicators of mental health and health behaviour. A prevalence of around 10% for both short- and long sleep duration and poor sleep quality was found. All were associated with poor mental health-related quality of life, depression, stress, perceived stressors and obesity. In addition, short sleep duration was associated with daily smoking, and long sleep duration was associated with physical inactivity and daily smoking. Our findings revealed a stronger association between sleep problems and mental health indicators in comparison to health behaviours. We found that sleep duration and sleep quality in broad terms were associated with similar variables within mental health and health behaviour. These findings underline the importance of adopting a comprehensive approach to addressing sleep problems in the context of health promotion, disease prevention, treatment and rehabilitation.

Posttraumatic stress disorder, depressive and cardiovascular disease symptoms among young patients receiving medical treatment in a heart centre: A cross-sectional study.

Exploring the connections between traumatic experiences and subsequent health outcomes is vital for informing clinical practices and public health policies. The study aimed to investigate the relationship between lifetime trauma exposure and posttraumatic stress disorder (PTSD), depressive and cardiovascular disease (CVD) symptoms. A total of 171 patients who received treatment in a local heart centre were included in this study. Several questionnaires such as the Life Event Checklist-5, Posttraumatic Stress Disorder Checklist for DSM-5 and Patient Health Questionnaire-9 were used to measure their traumatic experiences and PTSD and depressive symptoms, respectively. Physiological measures were also examined. Data were analysed using SPSS. The chi-square test showed significant differences in the percentage of reported PTSD symptoms among the patients with CVD (24.0%), patients with kidney disease (4.3%) and patients with other health problems (7.1%). The patients with CVD reported having a significantly higher percentage of PTSD and depressive symptoms than the patients with other medical conditions. The patients with CVD who reported having PTSD symptoms had significant systolic blood pressure (SBP) and heart rate changes compared to the patients who did not. The patients who reported PTSD symptoms had a significantly shorter sleep duration than their counterparts. The SBP and diastolic blood pressure differed significantly between the patients with and without PTSD symptoms. Earlier detection, prevention and intervention related to trauma exposure and PTSD symptoms are suggested to reduce the CVD risk.

Subjective sleep parameters: A marker to PTSD symptoms evolution? A 4-year longitudinal study

Disturbed sleep is a common feature after exposure to a traumatic event, especially when PTSD develops. However, although there is evidence suggesting a potential role of sleep disturbance in the progression of PTSD symptoms, the interrelationship between sleep and PTSD symptoms has yet to be determined. In order to address this knowledge gap, we have investigated the influence of initial sleep characteristics on the evolution of post-traumatic stress disorder (PTSD) symptoms over 4 years of follow-up among individuals exposed to the Brazilian Kiss nightclub fire. Participants were individuals exposed to the 2013 Kiss nightclub fire in Brazil. Sleep characteristics and PTSD symptoms were measured within the 4 years following the fire by self-report questionnaires, such as The Pittsburgh Sleep Quality Index (PSQI), and PTSD Checklist - Civilian version (PCL-C). Generalized estimating equations (GEE) models were used to examine the longitudinal associations (by estimating the relative effects of initial sleep problems on PTSD symptoms after adjusting for covariates). Comprehensive information concerning socio-demographic factors, health status, and sleep complaints were obtained. A total of 232 individuals were included. In GEE models, no significant interactions were observed between sociodemographic variables and PTSD symptoms in the follow-up period, however, associations were found between PTSD at baseline and the following factors: the female gender, the victim individuals and the existence of prior psychiatric disease. Initial subjective sleep parameters were strongly associated with PTSD symptoms over 4 years, mainly the presence of disturbed dreams (p = 0.012), increased sleep latency (p = 0.029), and reduced sleep duration (p = 0.012). Sleep complaints and PTSD symptoms were common among individuals after the disaster. The current study has found that the presence of sleep complaints, especially increased sleep latency, presence of disturbed dreams and short sleep duration, in the initial presentation after the fire was consistently associated with the perpetration of PTSD symptoms in the next 4 years of follow-up. These findings suggest that interventions addressing these sleep complaints have the potential to reduce the persistence and/or severity of PTSD symptoms.

Unraveling the Tapestry of Depression: A Cross-Sectional Study.

An often-occurring and severely disabling mental illness that mostly affects older people living in urban slums is depression. Developing successful therapies requires an understanding of the complex interactions between the different factors that contribute to depression in this susceptible population. This study aimed to find the prevalence of depression and identify the factors associated with depression in the geriatric population aged ≥60 years in the study area during the study period in Gujarat, India. This study was carried out among 450 participants aged ≥60 years. Face-to-face interviews and standardized assessment tools, including the Geriatric Depression Scale (GDS) for depression and the Mini-Cog test for cognitive impairment, were used to collect data on depression levels, sociodemographic characteristics, behavioral factors, medical conditions, life events, and psychiatric history. Statistical analyses, including chi-squared tests, were performed to assess the associations. Significant associations were found between various factors and depression levels, which were lower education (11.11% severe depression among non-literate vs. 2.11% among literate, p<0.001)and widowhood (11.56% severe depression among widowed vs. 4.53% among married, p<0.001), which were linked to higher depression severity. Behavioral risk factors like short sleep duration (<6 hours at night: 21.71% severe depression, p<0.001), tobacco snuffing (16.24% severe depression, p<0.001), and lack of physical activity (28.71% severe depression, p<0.001) were strongly associated with increased depression. Medical conditions such as hypertension (10.36% severe depression, p<0.001) and stressful life events like family conflicts (16.67% severe depression, p<0.001) exhibited strong associations. A personal history of depression (38.82% severe depression, p<0.001) was a potent predictor. The study highlights the multifaceted nature of depression in the geriatric population of the study area, underscoring the necessity of all-encompassing measures to tackle the recognized possible risk factors. The results provide valuable insights for developing targeted prevention strategies, healthcare policies, and support systems to enhance the mental well-being of this vulnerable population.

Association of sleep timing, sleep duration, and sleep latency with metabolic syndrome in middle-aged adults in Korea: A cross-sectional and longitudinal study

ObjectiveSleep is a potential risk factor for metabolic syndrome. We investigated the associations of various sleep characteristics with the status and incidence of metabolic syndrome in middle-aged Koreans. MethodsUsing data from a community-based Korean Medicine Daejeon Citizen Cohort study on participants aged 30-50years, cross-sectional (n = 1984) and longitudinal (n = 1216, median follow-up: 2.1years) analyses were performed. To study the association of metabolic syndrome and five components with various sleep characteristics, measured using the Pittsburgh Sleep Quality Index, we used Poisson and logistic regression and Cox proportional hazard regression analyses, adjusting for covariates. ResultsOf 1984 participants, 66%, 19%, and 15% belonged to the non-metabolic syndrome, pre-metabolic syndrome, and metabolic syndrome groups, respectively. After covariate adjustments, the pre-metabolic syndrome group was associated with late mid-sleep time (≥5:00; prevalence ratios 1.61, 95% confidence interval 1.01-2.54) and late bedtime (≥2:00; prevalence ratios 1.55, 95% confidence interval 1.03-2.34), and the metabolic syndrome group was associated with long sleep latency (prevalence ratios 1.33, 95% confidence interval 1.03-1.73), poor sleep quality (prevalence ratios 1.38, 95% confidence interval 1.07-1.78), and early wake time (<6:00; prevalence ratios 1.29, 95% confidence interval 1.01-1.63). Longitudinal analysis of participants without metabolic syndrome at baseline indicated a significant increase in metabolic syndrome risk associated with very short sleep duration (<6 hours; hazard ratio 1.72, 95% confidence interval 1.06-2.79), long sleep latency (>30 minutes; hazard ratio 1.86, 95% confidence interval 1.1-3.12), and early wake time (<6:00 o’clock; hazard ratio 1.73, 95% confidence interval 1.01-2.97). ConclusionSleep characteristics, such as short duration, long latency, and early wake time, were associated with an increased risk of metabolic syndrome in middle-aged adults.

Expression of Concern: "Short and long sleep durations are both associated with increased risk of stroke: a meta-analysis of observational studies".

Expression of Concern: "Short and long sleep durations are both associated with increased risk of stroke: a meta-analysis of observational studies".

Pre-COVID-19 short sleep duration and eveningness chronotype are associated with incident suicidal ideation during COVID-19 pandemic in medical students: a retrospective cohort study.

Cross-sectional evidence suggests that sleep problems increased the risk of suicide during the 2019 coronavirus disease (COVID-19) pandemic. However, a lack of longitudinal studies examined the relationship between pre-COVID-19 sleep duration, chronotype and incident suicide during the COVID-19 pandemic. Thus, we examined these associations in a longitudinal study of medical students. From the Shantou College Student Sleep Cohort, a total of 333 first and second grade medical students (age 19.41 ± 0.82 years, female 61.26%), without suicidal ideation (SI) at pre-COVID-19 period, were followed up during the COVID-19 pandemic. Incident SI was defined by their response to the 9th question from the Beck Depression Inventory. Short sleep duration was defined as less than 7 h/night. The Morningness-Eveningness Questionnaire was used to evaluate the participants' chronotype. Logistic regression with adjusted odds ratios (AOR) and 95% confidence intervals (95% CI) was used to examine the association between sleep and SI. The incidence of SI during the COVID-19 pandemic was 5.71%. Logistic regressions with confounding factors adjustment showed that both short sleep duration (AOR = 4.91, 95% CI = 1.16-20.74) and eveningness (AOR = 3.80, 95% CI = 1.08-13.30) in the pre-COVID-19 period were associated with increased risk of incident SI during the COVID-19 pandemic. Pre-COVID-19 short sleep duration and eveningness predict incident SI during the COVID-19 pandemic in medical students. Prolonging sleep duration may help to decrease SI during major public health crises.

Sleep Patterns and Tryptophan Consumption among Students at Spanish Universities: The Unihcos Project.

The objective of this cross-sectional study was to explore sleep patterns and the potential relationship between sleep and tryptophan intake among Spanish university students. A total of 11,485 students self-reported their sleep and dietary patterns and habits. Tryptophan intake was calculated using a food intake matrix and results were presented as quartiles of total intake. Short sleep duration prevalence was 51.0%, with males exhibiting a significantly higher frequency. A total of 55.0% of participants presented inadequate sleep efficiency, with males again presenting a higher rate. Median tryptophan intake was 692.16 ± 246.61 mg/day, 731.84 ± 246.86 mg/day in males and 677.24 ± 244.87 mg/day in females (p = 0.001). Dietary tryptophan intake below the first quartile (<526.43 mg/day) was associated with a higher risk of short sleep duration in males (1.26; 95%CI: 1.02-1.55) and females (1.19; 95%CI: 1.05-1.34) and with the Athens Insomnia Scale insomnia in males (2.56; 95%CI: 1.36-4.82) and females (1.47; 95%CI: 1.10-2.05). Regarding academic specializations, females in the humanities field showed a higher risk of Athens Insomnia Scale insomnia due to low tryptophan intake (Q1: 3.15; 95% CI: 1.04-9.55 and Q2: 3.41; 95%CI: 1.01-11.5). In summary, lower tryptophan consumption appears to be associated with poorer sleep quality in Spanish university students; however, other social factors affecting students may also influence sleep quality. These findings have important implications for nutritional recommendations aimed at enhancing tryptophan intake to improve sleep quality.

Childhood sleep is prospectively associated with adolescent alcohol and marijuana use

IntroductionPrior studies have examined the cross-sectional relationship between adolescent sleep and substance use; however, fewer have explored the long-term connections between childhood sleep and adolescent substance use. MethodsThis study investigated both cross-sectional associations during adolescence and prospective associations between childhood weeknight sleep and later alcohol and marijuana use in the Future of Families and Child Wellbeing Study, a diverse national birth cohort of urban children from 20 cities with populations greater than 200,000. Parents reported their child’s bedtime at ages 3, 5, and 9 and their child’s sleep duration at ages 5 and 9. ResultsAt age 15, adolescents self-reported their bedtime, sleep duration, and alcohol and marijuana use (n = 1514). Logistic regression analyses for each substance use outcome at age 15 were adjusted for sex, age at time of assessment, race/ethnicity, income-relative-to-poverty threshold, family structure, and caregiver education level. At age 15, later bedtime (AOR=1.39; 95 % CI=1.22, 1.57) and shorter sleep duration (AOR=1.28; 95 % CI=1.14, 1.43) were associated with greater odds of consuming a full drink of alcohol more than once, and later bedtime was associated with greater odds of trying marijuana (AOR=1.35; 95 % CI=1.20, 1.51). Unexpectedly, later bedtimes at age 3 were associated with lower odds of drinking alcohol by age 15 (AOR=0.74; 95 % CI=0.59, 0.92). In contrast, later bedtimes at age 9 were associated with greater odds of drinking alcohol (AOR=1.45; 95 % CI=1.11, 1.90). Additionally, later bedtime at age 5 (AOR=1.26; 95 % CI=1.01, 1.58) and shorter sleep duration at age 9 (AOR=1.19; 95 % CI=1.04, 1.36) were associated with greater odds of trying marijuana. Conclusion: Taken together, these associations support the importance of protecting childhood sleep habits to reduce the likelihood of substance use starting as early as mid-adolescence. Implications and contributionIn this longitudinal cohort study, adolescents were more likely to have consumed alcohol or tried marijuana by age 15 if they had later bedtimes and shorter sleep duration during childhood and adolescence. Protecting sleep health throughout childhood may reduce the likelihood of substance use during early adolescence.

Effects of low-dose acetylsalicylic acid on the inflammatory response to experimental sleep restriction in healthy humans

BackgroundSleep deficiencies, such as manifested in short sleep duration or insomnia symptoms, are known to increase the risk for multiple disease conditions involving immunopathology. Inflammation is hypothesized to be a mechanism through which deficient sleep acts as a risk factor for these conditions. Thus, one potential way to mitigate negative health consequences associated with deficient sleep is to target inflammation. Few interventional sleep studies investigated whether improving sleep affects inflammatory processes, but results suggest that complementary approaches may be necessary to target inflammation associated with sleep deficiencies. We investigated whether targeting inflammation through low-dose acetylsalicylic acid (ASA, i.e., aspirin) is able to blunt the inflammatory response to experimental sleep restriction. Methods46 healthy participants (19F/27M, age range 19–63 years) were studied in a double-blind randomized placebo-controlled crossover trial with three protocols each consisting of a 14-day at-home monitoring phase followed by an 11-day (10-night) in-laboratory stay (sleep restriction/ASA, sleep restriction/placebo, control sleep/placebo). In the sleep restriction/ASA condition, participants took low-dose ASA (81 mg/day) daily in the evening (22:00) during the at-home phase and the subsequent in-laboratory stay. In the sleep restriction/placebo and control sleep/placebo conditions, participants took placebo daily. Each in-laboratory stay started with 2 nights with a sleep opportunity of 8 h/night (23:00–07:00) for adaptation and baseline measurements. Under the two sleep restriction conditions, participants were exposed to 5 nights of sleep restricted to a sleep opportunity of 4 h/night (03:00–07:00) followed by 3 nights of recovery sleep with a sleep opportunity of 8 h/night. Under the control sleep condition, participants had a sleep opportunity of 8 h/night throughout the in-laboratory stay. During each in-laboratory stay, participants had 3 days of intensive monitoring (at baseline, 5th day of sleep restriction/control sleep, and 2nd day of recovery sleep). Variables, including pro-inflammatory immune cell function, C-reactive protein (CRP), and actigraphy-estimated measures of sleep, were analyzed using generalized linear mixed models. ResultsLow-dose ASA administration reduced the interleukin (IL)-6 expression in LPS-stimulated monocytes (p<0.05 for condition*day) and reduced serum CRP levels (p<0.01 for condition) after 5 nights of sleep restriction compared to placebo administration in the sleep restriction condition. Low-dose ASA also reduced the amount of cyclooxygenase (COX)-1/COX-2 double positive cells among LPS-stimulated monocytes after 2 nights of recovery sleep following 5 nights of sleep restriction compared to placebo (p<0.05 for condition). Low-dose ASA further decreased wake after sleep onset (WASO) and increased sleep efficiency (SE) during the first 2 nights of recovery sleep (p<0.001 for condition and condition*day). Baseline comparisons revealed no differences between conditions for all of the investigated variables (p>0.05 for condition). ConclusionThis study shows that inflammatory responses to sleep restriction can be reduced by preemptive administration of low-dose ASA. This finding may open new therapeutic approaches to prevent or control inflammation and its consequences in those experiencing sleep deficiencies. Trial RegistrationClinicalTrials.gov NCT03377543.

Sleep Duration Alters Overfeeding-mediated Reduction in Insulin Sensitivity.

Weight gain and sleep restriction both reduce insulin sensitivity. However, it is not known if sleep duration alters glucose metabolism in response to overfeeding. To examine the effect of sleep duration on overfeeding-mediated alterations in carbohydrate metabolism and insulin sensitivity. Retrospective exploratory analysis of a longitudinal overfeeding study in healthy participants (n = 28, age: 26.9 ± 5.5 years, body mass index: 25.74 ± 2.45 kg/m2). After providing baseline study measures, participants were overfed 40% above weight maintenance calorie requirements for 8 weeks. Insulin sensitivity was determined by a 2-step hyperinsulinemic-euglycemic clamp. Baseline habitual sleep duration was estimated by accelerometry, and sleep groups were created based on median sleep duration (5.2 hours/night). Overfeeding led to an average body weight gain of 7.3 ± .4 kg. Habitual sleep duration did not alter overfeeding-mediated body weight gain, fat gain, and fat distribution (all P > .15). Compared to participants with more sleep, fasting insulin (P = .01) and homeostatic model assessment for insulin resistance (P = .02) increased while fasting glucose remained unchanged (P = .68) with overfeeding in participants with shorter sleep duration. Glucose infusion rate during high insulin dose was reduced with overfeeding in participants with short sleep duration but not in participants with more sleep (P < .01). Overfeeding mediated weight gain reduced liver, adipose, and whole-body insulin sensitivity prominently in individuals with short sleep duration but not in individuals with longer sleep duration. This suggests that promoting adequate sleep during short periods of overeating may prevent detrimental effects on glucose metabolism.

A Large-Scale Genome-Wide Study of Gene-Sleep Duration Interactions for Blood Pressure in 811,405 Individuals from Diverse Populations.

Although both short and long sleep duration are associated with elevated hypertension risk, our understanding of their interplay with biological pathways governing blood pressure remains limited. To address this, we carried out genome-wide cross-population gene-by-short-sleep and long-sleep duration interaction analyses for three blood pressure traits (systolic, diastolic, and pulse pressure) in 811,405 individuals from diverse population groups. We discover 22 novel gene-sleep duration interaction loci for blood pressure, mapped to 23 genes. Investigating these genes' functional implications shed light on neurological, thyroidal, bone metabolism, and hematopoietic pathways that necessitate future investigation for blood pressure management that caters to sleep health lifestyle. Non-overlap between short sleep (12) and long sleep (10) interactions underscores the plausible nature of distinct influences of both sleep duration extremes in cardiovascular health. Several of our loci are specific towards a particular population background or sex, emphasizing the importance of addressing heterogeneity entangled in gene-environment interactions, when considering precision medicine design approaches for blood pressure management.