Prenatal and early childhood exposure to tetrachloroethylene (PCE)-contaminated drinking water and sleep quality in adulthood: a retrospective cohort study

Background Communities in Cape Cod, Massachusetts were exposed to tetrachloroethylene (PCE) through contaminated drinking water from 1969 to 1983. PCE exposure during adulthood has well-established neurotoxic effects; however, long-term impacts stemming from early life exposure, especially adverse effects on sleep quality, are not well understood. Methods The present analysis was based on data from the Cape Cod Health Study, a retrospective cohort study of the long-term neurotoxic impacts of early-life exposure to PCE-contaminated drinking water. Exposure to PCE-contaminated water was estimated using a validated leaching and transport model. Measures of sleep quality were obtained from self-administered questionnaires. Generalized estimating equations were used to generate risk ratios and 95% confidence intervals to estimate the association between early-life PCE exposure and sleep quality among 604 participants. Results Compared to unexposed participants, any PCE exposure during early life was associated with 1.57 times the risk of reporting breathing pauses during sleep (95% CI 0.92–2.68). Low-level exposure to PCE was associated with 1.50 times the risk of reporting sleep apnea or other sleep disorders (95% CI 0.78–2.89), while high levels of exposure had comparable risk compared to no exposure (RR = 0.94, 95% CI 0.50–1.79). Weak or no associations were observed for other sleep quality outcomes. In stratified analyses participants with mental illness and/or substance use disorder had increased risk ratios for short sleep duration associated with PCE exposure. Conclusion These findings suggest that early-life exposure to PCE may be associated with a moderate increase in the risk of reporting breathing pauses during sleep in adulthood and that a history of mental illness and/or substance use disorder may exacerbate the risk of short sleep duration.

Sleep deficiency in spaceflight is associated with degraded neurobehavioral functions and elevated stress in astronauts on six-month missions aboard the International Space Station

Astronauts are required to maintain optimal neurobehavioral functioning despite chronic exposure to the stressors and challenges of spaceflight. Sleep of adequate quality and duration is fundamental to neurobehavioral functioning, however astronauts commonly experience short sleep durations in spaceflight (<6 h). As humans embark on long-duration space exploration missions, there is an outstanding need to identify the consequences of sleep deficiency in spaceflight on neurobehavioral functions. Therefore, we conducted a longitudinal study that examined the sleep-wake behaviors, neurobehavioral functions, and ratings of stress and workload of N=24 astronauts before, during, and after 6-month missions aboard the International Space Station (ISS). The computerized, Reaction SelfTest (RST), gathered astronaut report of sleep-wake behaviors, stress, workload, and somatic behavioral states; the RST also objectively assessed vigilant attention (i.e., Psychomotor Vigilance Test-Brief). Data collection began 180 days before launch, continued every 4 days in-flight aboard the ISS, and up to 90 days post-landing, which produced N=2,856 RSTs. Consistent with previous ISS studies, astronauts reported sleeping ~6.5 h in-flight. The adverse consequences of short sleep were observed across neurobehavioral functions, where sleep durations <6 h were associated with significant reductions in psychomotor response speed, elevated stress, and higher workload. Sleep durations <5 h were associated with elevated negative somatic behavioral states. Furthermore, longer sleep durations had beneficial effects on astronaut neurobehavioral functions. Taken together, our findings highlight the importance of sleep for the maintenance of neurobehavioral functioning and as with humans on Earth, astronauts would likely benefit from interventions that promote sleep duration and quality.

Sympathetic neural responses to sleep disorders and insufficiencies

Short sleep duration and poor sleep quality are associated with cardiovascular risk, and sympathetic nervous system (SNS) dysfunction appears to be a key contributor. The present review will characterize sympathetic function across several sleep disorders and insufficiencies in humans, including sleep deprivation, insomnia, narcolepsy, and obstructive sleep apnea (OSA). We will focus on direct assessments of sympathetic activation (e.g., plasma norepinephrine and muscle sympathetic nerve activity), but include heart rate variability (HRV) when direct assessments are lacking. The review also emphasizes sex as a key biological variable. Experimental models of total sleep deprivation and sleep restriction are converging to support epidemiological studies reporting an association between short sleep duration and hypertension, especially in women. A systemic increase of SNS activity via plasma norepinephrine is present with insomnia, and has also been confirmed with direct, regionally-specific evidence from microneurographic studies. Narcolepsy is characterized by autonomic dysfunction via both HRV and microneurographic studies, but with opposing conclusions regarding SNS activation. Robust sympathoexcitation is well documented in OSA, and is related to baroreflex and chemoreflex dysfunction. Treatment of OSA with continuous positive airway pressure results in sympathoinhibition. In summary, sleep disorders and insufficiencies are often characterized by sympathoexcitation and/or sympathetic/baroreflex dysfunction, with several studies suggesting women may be at heightened risk.

Factors associated with habitual sleep duration in US adults with hypertension: a cross-sectional study of the 2015–2018 National Health and Nutrition Examination Survey

Background The relationship between inadequate sleep duration and hypertension risk has been established in the general population, but there is a gap in the literature on predictors of habitual sleep duration in adults with hypertension. This study examined factors associated with habitual sleep duration among adults with hypertension in the United States (US). Methods Data of 5660 adults with hypertension were obtained by combining the 2015–2018 cycles of the National Health and Nutrition Examination Survey (NHANES). Survey weighted multinomial logistic regression models were fit to examine factors associated with short (< 7 h) and long (> 9 h) sleep duration with adequate sleep duration (7–9 h) as the reference. Results The prevalence of self-reported adequate sleep duration was 65.7%, while short sleep duration was 23.6%, and long sleep duration 10.7%. Short sleep duration (compared to adequate sleep duration) was positively associated with history of seeking help for sleeping difficulties (relative risk ratio [RRR], 1.25; 95% confidence interval [CI], 1.02–1.53), Non-Hispanic Black race/ethnicity (RRR, 2.08; 95% CI, 1.61–2.67), working ≥45 h/week (RRR, 1.81; 95% CI, 1.32–2.48), and negatively associated with older age ≥ 65 years (RRR, 0.63; 95% CI, 0.45–0.91) and female gender (RRR, 0.70; 95% CI, 0.56–0.88). Long sleep duration was positively associated with female gender (RRR, 1.24; 95% CI, 1.001–1.54), chronic kidney disease (RRR, 1.48; 95% CI, 1.14–1.92), moderate depressive symptoms (RRR, 1.62; 95% CI, 1.08–2.44), moderately severe to severe depressive symptoms (RRR, 1.89; 95% CI, 1.05–3.43), being in retirement (RRR, 3.46; 95% CI, 2.18–5.49), and not working due to health reasons (RRR, 4.87; 95% CI, 2.89–8.22) or other reasons (RRR, 3.29; 95% CI, 1.84–5.88). Conclusion This population-based study identified factors independently associated with habitual sleep duration in adults with hypertension. These included help-seeking for sleeping difficulty, gender, age, chronic kidney disease, depressive symptoms, race/ethnicity, and employment status. These findings can help in the development of tailored approaches for promoting adequate sleep duration in adults with hypertension.

Losing sleep by staying up late leads adolescents to consume more carbohydrates and a higher glycemic load

This study examined how short sleep impacts dietary consumption in adolescents by testing whether experimentally shortening sleep influences the amount, macronutrient content, food types, and timing of food consumed. Ninety-three adolescents completed a within-subjects crossover paradigm comparing five nights of short sleep (6.5-hour sleep opportunity) to five nights of Healthy Sleep (9.5-hour sleep opportunity). Within each condition, adolescents completed three multiple-pass dietary recalls that recorded the types, amount, and timing of food intake. The following outcomes were averaged across days of dietary recall within condition: kilocalories, grams of carbohydrates, fat, protein, and added sugars, glycemic load of foods, and servings of specific types of foods (low-calorie drinks, sweetened drinks, fruits/vegetables, meats/proteins, processed snacks, “fast food” entrees, grains, and sweets/desserts). Timing of consumption of kilocalorie and macronutrient outcomes were also examined across four noncumulative time bins: 06:00–10:59, 11:00–15:59, 16:00–20:59, and 21:00–01:00. Adolescents slept 2 h and 20 min longer in Healthy Sleep than in Short Sleep (p &lt; .0001). While in Short Sleep, adolescents ate more grams of carbohydrates (p = .031) and added sugars (p = .047), foods higher in glycemic load (p = .013), and servings of sweet drinks (p = .023) and ate fewer servings of fruits/vegetables (p = .006) compared to Healthy Sleep. Differences in consumption of kilocalories, fat, and carbohydrates emerged after 9:00 pm (ps = .012, .043, .006, respectively). These experimental findings suggest that adolescents who have insufficient sleep exhibit dietary patterns that may increase the risk for negative weight and cardiometabolic outcomes. Future health promotion efforts should include promoting optimal sleep to increase healthy dietary habits.

Associations of Sleep Problems with Asthma and Allergic Rhinitis Among Chinese Preschoolers: A Cross-Sectional Study

Background The aim of this study was to examine the associations of sleep problems with asthma and allergic rhinitis among Chinese preschoolers. Methods This cross-sectional survey was conducted in Guangzhou, China. Children aged 3-6 years were selected from 32 kindergartens in 7 regions. Asthma, allergic rhinitis and sleep problem were evaluated by a valid questionnaire. Binary logistic regression models were employed to estimate the odds ratios (OR) and 95% confidence intervals (CI) for asthma and allergic rhinitis according to short sleep duration, late bedtime and frequent nocturnal awaking. Results We included 4876 preschool children. Of these, 182 (3.7%) diagnosed as asthma, and 511 (10.5%) diagnosed as allergic rhinitis. Frequent nocturnal awakening was associated with asthma and allergic rhinitis, adjusted OR were 1.49(95% CI: 1.05~2.13) and 1.59(95%CI: 1.27-1.99), respectively. Further subgroup analysis showed the association of frequent nocturnal awakening with asthma differed by gender. No significant associations of short duration and late bedtime with asthma/ and allergic rhinitis were identified. Conclusions Our data suggested that frequent nocturnal awakening was associated with asthma and allergic rhinitis, and the association of frequent nocturnal awakening with asthma differed by gender. Further studies are warranted to address the causal relationship between nocturnal awaking and asthma and allergic rhinitis.

Gender differences in the association between sleep duration and body mass index, percentage of body fat and visceral fat area among chinese adults: a cross-sectional study

Background The relationship between sleep duration and anthropometric indices are still unclear. This study aimed to explore the association between sleep duration and body mass index (BMI), percentage of body fat (PBF) and visceral fat area (VFA) among Chinese adults, further to explore gender difference in it. Methods We analyzed part of the baseline data of a cohort study among adult attendees at two health-screening centers in China. Sleep duration was self-reported and categorized into short (< 7 h/day), optimal (7-9 h/day) and long sleep (≥ 9 h/day). BMI, PBF and VFA were assessed by bioelectric impedance analysis. Demographic characteristics, chronic diseases and medication history, physical activity, smoking and alcohol drinking behaviors were measured by an investigator-administrated questionnaire. Results A total of 9059 adult participants (63.08% were females) were included in the analysis. The participants aged from 19 to 91 years with the mean age of 45.0 ± 14.6 years. Short sleep was independently associated with elevated odds of general obesity (defined using BMI) and visceral obesity (defined using VFA) among the total study population, and gender differences were observed in these associations. Among women, short sleep was associated with 62% increased odds of general obesity (OR = 1.62, 95% CI: 1.24-2.12) and 22% increased odds of visceral obesity (OR = 1.22, 95% CI: 1.02-1.45). Among men, long sleep duration was associated with 21% decreased odds of visceral obesity (OR = 0.79, 95% CI: 0.64-0.99). No association was observed between sleep duration and PBF in both sexes. Conclusions Sleep duration was associated with increased odds of general and visceral obesity, and this association differed between men and women. No association was observed between sleep duration and PBF among either males or females.

Are Genetic and Environmental Contributions to Verbal Fluency and Episodic Memory Solely Moderated by Sleep?

Decreases in sleep duration and cognitive functioning often occur and co-occur in aging although these patterns are not universal. Underlying etiologies, i.e., genetic and environmental factors, contribute to why people differ on cognitive functioning at shorter versus longer sleep durations. The current study tested whether sleep duration alters the genetic and environmental contributions to why middle-aged and older adults vary on cognitive functioning. Using 4 twin studies from the Interplay of Genes and Environment Across Multiple Studies (IGEMS) consortium (Mage=56.5, range=35.0-91.2, N=5,210, 1,083 complete MZ pairs, 1,522 complete DZ pairs) we tested quantitative genetic twin models considering sleep, depressive symptoms, and age as moderators of verbal fluency (i.e., Animal Naming) and episodic memory (i.e., Word List). For verbal fluency, sleep duration and depressive symptoms were significant when dropped together from the model (χ2(6)=15.22, p=0.02) but not individually (χ2sleep(3)=7.17, p=0.07; χ2dep(3)=5.81, p=0.12), indicating that both moderators may affect differences in verbal fluency performance. For episodic memory, sleep duration moderation was only significant via the shared environmental factor (χ2(1)=5.26, p=0.02), indicating that sleep may affect differences in episodic memory performance via environmental influences that make siblings more similar to one another. Overall, results illustrate patterns of higher genetic influences on cognitive function at short sleep (4 hours) and higher shared environmental influences on cognitive function at long sleep (10 hours). These findings may align with associations of upregulation of neuroinflammatory processes at short sleep and common reporting of mental fatigue at long sleep, both of which are associated with poorer cognitive functioning.