Relationship of sleep quantity and quality with 24-hour urinary catecholamines and salivary awakening cortisol in healthy middle-aged adults

Joint association of physical activity and night sleep duration with the risk of atherosclerotic cardiovascular disease

OBJECTIVES

To investigate the joint association of physical activity (PA) and sleep duration with the risk of atherosclerotic cardiovascular disease (ASCVD).

METHODS

A total of 111,714 participants who participated in health examinations were enrolled from the Kailuan Study between June 2006 and December 2009. Sleep duration was divided into three groups (short, healthy, and long). PA was categorized into physically inactive and physically active. Restricted cubic splines were used to analyze the associations of PA and sleep duration with ASCVD. Cox proportional hazards models were conducted to investigate the effects of PA and sleep duration on ASCVD risk, with their cross-product interaction terms tested on both multiplicative and additive scales.

RESULTS

During 13.05 ± 3.16 years of follow-up, 10,408 participants developed ASCVD. Restricted cubic spline analysis revealed a nonlinear dose-response relationship between sleep duration and ASCVD risk among physically inactive participants (Pnonlinear <0.05). Both additive and multiplicative interactions between physical activity and sleep duration were observed in their effects on ASCVD risk (Pinteraction < 0.05). Compared with participants who had healthy sleep duration and were physically active, those with unhealthy sleep duration and physical inactivity exhibited a significantly higher risk of ASCVD [short sleep duration: HR (95 %CI) = 1.19 (1.09, 1.30); long sleep duration: HR (95 % CI) = 1.10 (0.90, 1.34)]. However, physically active participants in both the short and long sleep duration groups exhibited a reduced risk of ASCVD.

CONCLUSIONS

Engaging in sufficient PA can reduce the risk of ASCVD in individuals with short sleep duration. Therefore, simultaneously maintaining healthy sleep duration and engaging in PA may effectively prevent ASCVD.

Guidelines for the standardization of pre-analytical variables for salivary biomarker studies in Alzheimer's disease research: An updated review and consensus of the Salivary Biomarkers for Dementia Research Working Group

There is a pressing need for accessible biomarkers with high diagnostic accuracy for Alzheimer's disease (AD) diagnosis to facilitate widespread screening, particularly in underserved groups. Saliva is an emerging specimen for measuring AD biomarkers, with distinct contexts of use that could complement blood and cerebrospinal fluid and detect various analytes. An interdisciplinary, international group of AD and related dementias (ADRD) researchers convened and performed a narrative review of published studies on salivary AD biomarkers. We critically appraised the current state of the literature, examining both consistencies and discrepancies in existing pre-analytical variables and methodologies. We discussed how various pre-analytical variables could influence the detection and quantification of salivary biomarkers, showed technologies available to standardize collection procedures, and proposed a standardized pre-analytical protocol to guide future studies on salivary AD biomarker examinations. We identified potential contexts of use, gaps, and priorities and proposed future research directions. HIGHLIGHTS: Given its non-invasive nature, wider accessibility, and cultural acceptability, particularly in low-resourced settings, saliva is a biofluid complementary to blood and CSF. Current salivary AD biomarker studies do not control for many confounding pre-analytical variables during the sampling process, potentially leading to inaccurate salivary biomarker readings and conclusions, contributing to conflicting findings. Reviewing the current literature, including the consistencies and non-consistencies observed in the existing parameters and methodologies, discussing how they can affect salivary AD biomarker detection and quantification. Proposing a standardized salivary pre-analytical protocol, identifying the gaps and prioritizations needed to move this area forward, proposing future directions and potential contexts of use.

The impact of sleep problems on cerebral aneurysm risk is mediated by hypertension: a mediated Mendelian randomization study

Introduction

Cerebral aneurysm (CA) is a common vascular disease. The risk factors of CA include hypertension, smoking, and a family history of genetic predisposition. Although sleep-related problems have been found to have a strong association with cardiovascular disease, there is a lack of research regarding the causal relationship with cerebral aneurysms.

Methods

In this study, we investigated the causal relationship between four sleep-related problems, including snoring, insomnia, narcolepsy, and napping during the day, and CA using a two-sample Mendelian randomization (MR) analysis. Moreover, the potential confounders before sleep problems and CA were further analyzed by multivariate MR (MVMR).

Results

The causal relationship between insomnia and CA was obtained analytically by means of six MR analyses. There was a strong causal effect relationship between insomnia and CA, which suggests this as a potential risk factor [odds ratio (OR) = 8.35, 95% confidence interval (CI) = 2.422-28.791, p = 7.772e-04]. On this basis, hypertension was identified as a mediator between insomnia and CA by MVMR, with a mediating effect of 52.538% (OR = 3.05, 95% CI = 1.549-4.55, p = 0.015).

Conclusion

The causal relationship between insomnia and CA was predicted using genetic variance data, and insomnia was found to be a potential risk factor. Furthermore, hypertension is a mediator between insomnia and CA. Therefore, focusing on sleep problems and improving sleep quality may be an active and effective strategy to prevent CA.

Associations of sleep with cardiometabolic risk factors and cardiovascular diseases: An umbrella review of observational and mendelian randomization studies

Two researchers independently assessed studies published up to February 5, 2023, across PubMed, Web of Science, Embase, and Cochrane Library, to investigate the associations of sleep traits with cardiometabolic risk factors, as well as with cardiovascular diseases. Fourteen systematic reviews consisting of 23 meta-analyses, and 11 Mendelian randomization (MR) studies were included in this study. Short sleep duration was associated with a higher risk of obesity, type 2 diabetes (T2D), hypertension, stroke, and coronary heart disease (CHD) in observational studies, while a causal role was only demonstrated in obesity, hypertension, and CHD by MR. Similarly, long sleep duration showed connections with a higher risk of obesity, T2D, hypertension, stroke, and CHD in observational studies, none was supported by MR analysis. Both observational and MR studies indicated heightened risks of hypertension, stroke, and CHD in relation to insomnia. Napping was linked to elevated risks of T2D and CHD in observational studies, with MR analysis confirming a causal role in T2D. Additionally, snoring was correlated with increased risks of stroke and CHD in both observational and MR studies. This work consolidates existing evidence on a causal relationship between sleep characteristics and cardiometabolic risk factors, as well as cardiovascular diseases.

Disease Modules Associated with Unfavorable Sleep Patterns and Their Genetic Determinants: A Prospective Cohort Study of the UK Biobank

Despite the established associations between sleep-related traits and major diseases, comprehensive assessment on affected disease modules and their genetic determinants is lacking. Using multiple correspondence analysis and the k-means clustering algorithm, 235,826 eligible participants were clustered into distinct unfavorable sleep patterns [short sleep duration (n = 10,073), snoring (22,419), insomnia (102,771), insomnia and snoring (62,909)] and favorable sleep pattern groups (37,654). The associations of unfavorable sleep patterns with 134 diseases were estimated using Cox regression models; and comorbidity network analyses were applied for disease module identification. Genetic determinants associated with each disease module were identified by genome-wide association studies (GWAS). During an average follow-up of 10.80 years, unfavorable sleep patterns featured by 'short sleep duration', 'snoring', 'insomnia', and 'insomnia and snoring' were associated with increased risk of 0, 9, 10, and 19 diseases, respectively. Furthermore, comorbidity network analyses categorized these affected diseases into three disease modules, characterized by predominant diseases related to digestive system, circulatory and endocrine systems (snoring-related patterns only), and musculoskeletal system (insomnia-related patterns only). Using the number of affected diseases, as an index of a person's susceptibility to each disease module [i.e., susceptible score (SS)], GWAS analyses identified five, one, and three significant loci associated with the residual SS of these aforementioned disease modules, respectively, which mapped to several potential biological pathways, including those related to hormone regulation and catecholamine uptake. In conclusion, individuals with unfavorable sleep patterns, particularly snoring and insomnia, had increased risk of multiple diseases. The identification of three major disease modules with their relevant genetic determinants may facilitate strategy development for precision prevention of future health decline.

Supplementary Information

The online version contains supplementary material available at 10.1007/s43657-023-00144-8.

Worse sleep architecture but not self-reported insomnia and sleepiness is associated with higher cortisol levels in menopausal women

OBJECTIVE

Worsening of sleep quality during menopause is well recognized. However, the underlying hormonal regulation is insufficiently described. In this study, we evaluated associations between sleep and cortisol levels.

STUDY DESIGN

Seventeen perimenopausal and 18 postmenopausal women were enrolled in a three-night sleep study. Diurnal blood sampling was performed during the third night and the following day.

MAIN OUTCOME MEASURES

Self-reported insomnia and sleepiness were evaluated with the Basic Nordic Sleep Questionnaire and sleep architecture with all-night polysomnography. Diurnal cortisol samples were collected at 20-min intervals. Correlation analyses and generalized linear models adjusted by age, body mass index, vasomotor symptoms and depressive symptoms were conducted.

RESULTS

In correlation analyses, self-reported insomnia and sleepiness were not associated with cortisol levels. Lower sleep efficiency, slow-wave sleep and stage 1 percentages, number of slow-wave sleep and of rapid-eye-movement (REM) periods, longer slow-wave sleep latency and higher wake after sleep onset percentage were associated with higher cortisol levels (all p < 0.05). Further, lower slow-wave sleep percentage and longer slow-wave sleep latency correlated with steeper daytime cortisol slope (i.e. day cortisol decrease, both p < 0.05). In adjusted generalized linear models, lower sleep efficiency and number of rapid-eye-movement periods as well as higher wake after sleep onset percentage correlated with higher cortisol levels; lower slow-wave sleep percentage correlated with higher cortisol awakening response.

CONCLUSIONS

Worse sleep architecture but not worse self-reported insomnia and sleepiness was associated with higher cortisol levels. This is important for understanding sleep in women, especially during the menopausal period.

Sleep Duration and Blood Pressure in Youth Referred for Elevated Blood Pressure Evaluation

OBJECTIVES

Sleep promotion is not specifically recommended as a target for hypertension management. We examined associations of sleep duration and timing with blood pressure parameters in patients referred to pediatric nephrology clinic for elevated blood pressure evaluation.

METHODS

This is a retrospective study of initial ambulatory blood pressure monitoring data and self-report sleep data collected from patients referred to nephrology clinic for the evaluation of elevated blood pressure. Linear and logistic regression modeling determined associations between sleep exposures (duration and timing) and continuous and dichotomous blood pressure outcomes, respectively, adjusted for age, sex, body mass index, and weekday versus weekend status.

RESULTS

The study sample included 539 patients with mean age 14.6 years and 56% meeting hypertension criteria. Sleep duration averaged 9.1 hours per night. Average timing of sleep onset and offset were 11:06 pm and 8:18 am, respectively. Longer sleep duration was associated with better daytime blood pressure parameters (eg, every extra hour of sleep duration was associated with a reduced odds of wake hypertension [odds ratio, 0.88; 95% CI, 0.79-0.99]). Later sleep onset was associated with worse daytime blood pressure parameters (eg, each additional hour of later sleep onset was associated with higher wake systolic blood pressure index [mean wake blood pressure/95th percentile]) (β = 0.07; 95% CI, 0.02-0.13). Associations were consistent across sex, age, body mass index, and weekday status.

CONCLUSIONS

Longer sleep duration and earlier sleep onset were associated with lower blood pressure. This suggests that sleep optimization may be an important target for intervention in hypertension management.

Association between weekend catch-up sleep and cardiovascular disease: Evidence from the National Health and Nutrition Examination Surveys 2017-2018

OBJECTIVES

This study aimed to investigate the relationship between the weekend catch-up sleep duration and cardiovascular disease prevalence among adults in the United States.

DESIGN

Cross-sectional study.

SETTING

The United States.

PARTICIPANTS

Participants from the 2017-2018 National Health and Nutrition Examination Survey (NHANES) who were 20years old or older (n = 3400).

MEASUREMENTS

Sociodemographic characteristics, sleep duration (weekday and weekend), and the presence of cardiovascular disease, hypertension, and diabetes were recorded for all participants. Weekend catch-up sleep was defined as sleeping 1 hour longer on weekends than on weekdays. Adjusted multivariable logistic regression analysis was conducted to assess the relationship of weekend catch-up sleep with cardiovascular disease.

RESULTS

Participants with cardiovascular disease had shorter weekend catch-up sleep than those without cardiovascular disease (P < .01). Participants with weekend catch-up sleep had a lower prevalence of cardiovascular disease (P < .01) than those with no significant change in weekend sleep duration. An adjusted multivariate logistic regression analysis showed that weekend catch-up sleep duration was significantly associated with the prevalence of angina (P = .04), stroke (P < .01), and coronary heart disease (P = .01). Weekend catch-up sleep was associated with reduced cardiovascular disease prevalence when the weekday sleep duration was <6 hours (P < .01). A stratified analysis of participants with <6 hours of sleep on weekdays showed that weekend catch-up sleep duration (>2 hours) was associated with reduced prevalence of cardiovascular disease (P = .01).

CONCLUSION

Our findings indicate that weekend catch-up sleep duration of >2 hours is strongly associated with reduced cardiovascular disease prevalence when the sleep duration is <6 hours on weekdays.

Lifestyle factors associated with presenteeism among city government office workers: a cross-sectional study

OBJECTIVES

Presenteeism is a critical issue in occupational health. This study aimed to examine the association between presenteeism and subjective sleep quality, smoking status, and alcohol consumption.

METHODS

Anonymous data of 777 workers in a Japanese city were retrospectively obtained from City Government Office A. They included variables like absolute presenteeism scores (measured using the Japanese version of the World Health Organization Health and Work Performance Questionnaire short form), gender, age, family status, subjective sleep quality, smoking status, and alcohol consumption. A binary logistic regression analysis was performed with gender, age, family status, subjective sleep quality, smoking status, and alcohol consumption as the independent variables, and absolute presenteeism scores equal to or below 40 as the dependent variable. A gender-stratified binary logistic regression analysis was also performed.

RESULTS

The logistic regression analysis results revealed that absolute presenteeism was positively associated with poor subjective sleep quality among all respondents (odds ratio [OR], 1.70; 95% CI, 1.18-2.44) and men (OR, 1.85; 95% CI, 1.12-3.05) and with current drinkers among women (OR, 3.49; 95% CI, 1.36-8.92); it was negatively associated with age among those who were ≥50 years old (OR, 0.50; 95% CI, 0.27-0.93) and with current drinkers among men (OR, 0.43; 95% CI, 0.20-0.92).

CONCLUSIONS

The factors associated with presenteeism differed between men and women office workers, suggesting that gender differences need to be considered when working toward improving workers' productivity.

Objective Sleep Duration and All-Cause Mortality Among People With Obstructive Sleep Apnea

Importance

The association between sleep duration and all-cause mortality remains unclear among people with obstructive sleep apnea (OSA).

Objective

To explore whether there is an association between sleep duration and all-cause mortality among people with OSA.

Design, Setting, and Participants

This cohort study investigated participants with OSA from the Sleep Heart Health Study (SHHS) in which participants were enrolled between 1995 and 1998 with questionnaires and polysomnography (PSG) assessment and followed up for a median of 11.8 years. SHHS was a multicenter community-based study; 2574 participants with OSA defined by apnea-hypopnea index (AHI) greater than or equal to 15 from SHHS were found; all of them had all-cause mortality data and were included in the study. Data were analyzed from November 2022 to October 2023.

Exposures

Participants were divided into 4 groups with objective sleep duration of (1) at least 7 hours, (2) 6 to less than 7 hours, (3) 5 to less than 6 hours, and (4) less than 5 hours, which was determined by total sleep time on PSG at baseline.

Main Outcomes and Measures

All-cause mortality was defined as deaths from any cause and its risk was compared among 4 OSA groups using Cox regression models.

Results

A total of 2574 participants with OSA were included (1628 [63.2%] men and 946 [36.8%] women; mean [SD] age, 65.4 [10.7] years; 211 [8.2%] Black, 2230 [86.6%] White, 133 [5.2%] other race). Overall, 688 all-cause deaths were observed in participants. Compared with the group sleeping at least 7 hours, the groups sleeping 6 to less than 7 hours (hazard ratio [HR], 1.53 [95% CI, 1.13-2.07]), 5 to less than 6 hours (HR, 1.40 [95% CI, 1.03-1.90]), and less than 5 hours (HR, 1.64 [95% CI, 1.20-2.24]) had significantly higher risks of all-cause mortality independent of AHI. Sensitivity analyses were performed among participants with available data of positive airway pressure treatment during follow-up and the finding was mostly consistent, albeit the HR for the group of 5 to less than 6 hours was not statistically significant.

Conclusions and Relevance

In this cohort study of 2574 participants with OSA, those with shorter objective sleep duration had higher risk of all-cause mortality independent of AHI compared with those sleeping at least 7 hours. Further studies would be needed to investigate health benefits of extending sleep length among people with OSA with short sleep duration.

Joint associations of asthma and sleep duration with cardiovascular disease and all-cause mortality: a prospective cohort study

PURPOSE

This study aimed to investigate the joint association of asthma and sleep duration with cardiovascular disease (CVD) and mortality risk.

METHODS

This prospective cohort study included 366,387 participants from the UK Biobank. The participants were divided into three groups based on their sleep duration (short: <7 h/d; referent: 65+ years: 7-8 h/d; ages 39-64 years: 7-9 h/d; and long: 65+ years: >8 h/d; ages 39-64 years: >9 h/d). Cox proportional hazards models were used to examine the association between asthma and sleep duration on CVD and all-cause mortality.

RESULTS

Participants with asthma and short sleep duration showed increased risk of CVD (hazard ratio [HR] 1.42; 95% confidence interval [CI] 1.34-1.51) and all-cause mortality (HR, 1.26; 95% CI, 1.17-1.36), compared with participants with no asthma in the referent sleep duration group. We documented significant additive interactions between asthma and short sleep duration in relation to CVD (relative excess risk due to interaction [RERI], 0.13; 95% CI, 0.04-0.23) and all-cause mortality (RERI, 0.12; 95% CI, 0.01-0.23).

CONCLUSIONS

Asthma and short sleep duration may have additive interactions on CVD and all-cause mortality risk, highlighting the importance of controlling asthma in combination with improving sleep duration.

Association between Sleep Quality and Cardiac Autonomic Modulation in Adolescents: A Cross Sectional Study

Objective  To analyze the impact of sleep quality/duration on cardiac autonomic modulation on physically active adolescents with obesity. Materials and Methods  The present cross-sectional study included 1,150 boys with a mean age of 16.6 ± 1.2 years. The assessment of cardiac functions included the frequency domain of heart rate variability (HRV; low frequency - LF; high frequency - HF; and the ratio between these bands -LF/HF -, defined as the sympathovagal balance), and each parameter was categorized as low / high . Physical activity levels and sleep quality/duration were obtained by questionnaires. Abdominal obesity was assessed and defined as waist circumference > 80 th percentile. Results  Poor sleep quality resulted in lower HF (odds ratio [OR]: 1.8; 95% confidence interval [95%CI]: 1.01-3.21]) regardless of physical activity and abdominal obesity. Moreover, the study found no association between sleep duration and HRV parameters in adolescents. Conclusion  Sleep quality, not sleep duration, reduces parasympathetic cardiac modulation apart from other factors such as physical activity and abdominal obesity in adolescents.

Sleep characteristics before assisted reproductive technology treatment predict reproductive outcomes: a prospective cohort study of Chinese infertile women

Sleep disorders affect mental and physical health. Infertile women undergoing assisted reproductive technology (ART) treatment are prone to sleep disorders. Sleep condition, its influencing factors, and the association between sleep condition and ART treatment outcomes before treatment have not been explored within a population with a large sample size. Therefore, we investigated the sleep characteristics of 1002 Chinese infertile women before ovulation induction and investigated the influencing factors (negative and positive psychological factors, demographics, and fertility characteristics). We also examined whether sleep conditions before treatment predicted reproductive outcomes. We found that 24.1% of participants reported poor sleep quality. Women with primary infertility reported poorer sleep than women with secondary infertility. Negative psychological factors, including depression, anxiety, and perceived stress were associated with poor sleep, whereas positive affect was linked with good sleep. Adverse sleep characteristics, including poor subjective sleep quality, sleep disturbances, and poor sleep efficiency, decreased the quantity and quality of oocytes retrieved, fertilization rates, and clinical pregnancy rates. This study indicates that before ART treatment, a large number of females with infertility suffer from sleep problems, which are affected by psychological factors and infertility type, and unhealthy sleep characteristics may impair treatment outcomes. Our findings highlight the importance of screening and treatment for sleep disorders before the enrollment of ART treatment in infertile women.

Effect of insomnia and excessive daytime sleepiness on cardiac functions in older adults

BACKGROUND

We investigated the potential harmful effect in older adults of insomnia and excessive daytime sleepiness (EDS) on myocardial functions and electrophysiologic changes of the heart in terms of heart rate and QT intervals corrected for heart rate (QTc).

METHODS

The study included 32 insomnia patients and 30 control subjects. An Insomnia Severity Index score of ≥15 indicated insomnia, while a score of <8 was accepted as the control group. The Epworth Sleepiness Scale was used to assess EDS, with a score of ≥11/24 points indicating EDS. Diastolic and systolic functions were evaluated in each patient by transthoracic two-dimensional, conventional and tissue Doppler echocardiography. Heart rate and QTc were calculated for electrophysiologic changes.

RESULTS

The mean age was 73.2 ± 7.9 years, with 59.7% being female. Biventricular systolic and diastolic functions were impaired in the insomnia patients. The E' value for diastolic function was lower in the patients with insomnia than the controls (5.99 ± 1.59 vs. 6.88 ± 0.97, P = 0.053). Furthermore, values for the systolic function parameters Lateral-S (7.41 ± 1.92 vs. 9.37 ± 1.83, P < 0.001), Septal-S (6.69 ± 1.40 vs. 8.10 ± 1.30, P = 0.001), and Tricuspid-S (12.25 ± 2.00 vs. 14.37 ± 3.13, P = 0.004) were lower for insomnia patients than for controls. In the case of EDS coexistence, the heart rate and QTc values were higher than the controls (76.47 ± 7.18 vs. 71.03 ± 10.95, P = 0.001, and 413.72 ± 28.24 vs. 394.67 ± 24.47, P = 0.015, respectively).

CONCLUSION

Insomnia is associated with impaired systolic-diastolic functions, independent of EDS. The co-existence of insomnia and EDS may lead to electrophysiological changes in older adults, including increased heart rate and longer QTc.

Joint Associations of Device-Measured Sleep Duration and Efficiency With All-Cause and Cause-Specific Mortality: A Prospective Cohort Study of 90 398 UK Biobank Participants

BACKGROUND

Both sleep duration and efficiency are essential for health outcomes. However, few studies have considered the effects of both sleep duration and efficiency on predicting the risks of mortality. This study investigated the independent and joint associations of accelerometer-measured sleep duration and efficiency with all-cause and cause-specific mortality.

METHODS

The UK Biobank is a cohort study of over 500 000 individuals recruited between 2006 and 2010. This study included participants wearing wrist accelerometers for 7 consecutive days between February 2013 and December 2015. Mortality was ascertained by the national death registries.

RESULTS

Of the 90 398 participants (age, 62.4 [7.8] years, 43.5% male) who were included, 2 685 deaths were reported within a median follow-up duration of 6.4 years. Both accelerometer-measured short (adjusted hazard ratios, 1.27; 95% confidence interval [CI]: 1.11-1.45) and long sleep duration (adjusted hazard ratios, 1.16; 95% CI: 1.06-1.28) were positively associated with the risks of all-cause mortality. Lower sleep efficiency was associated with an increased risk of all-cause and cause-specific mortality. Significant interaction existed between accelerometer-measured sleep duration and efficiency for the risk of all-cause mortality (Pinteraction = .001), participants with long sleep duration and lower sleep efficiency had a double mortality risk compared with those with higher sleep efficiency and normal sleep duration (adjusted hazard ratios = 2.11; 95% CI: 1.44-3.09).

CONCLUSIONS

Accelerometer-measured short/long sleep duration and lower sleep efficiency were associated with increased risks of mortality. Sleep efficiency modified the effects of long sleep duration on survival.

Eating behaviors and incident cardiovascular disease in Japanese people: The population-based Panasonic cohort study 14

Evidence on common eating behaviors to support the prevention of cardiovascular disease (CVD) in Japanese people is insufficient. This retrospective cohort study aimed to investigate the association of diet behaviors (e.g., skipping breakfast, eating speed, snack after dinner, and alcohol consumption) with incident CVD in Japanese individuals. Employees of Panasonic Corporation who underwent the annual health checkups and without a history of CVD at baseline were enrolled. The main outcome was incident 3-point major adverse cardiovascular events (MACE). The secondary outcomes were incident coronary artery disease (CAD) and stroke. To assess the effect of BMI, the subgroup analysis was conducted. In total, 132,795 participants were included. Overall, 3,115, 1,982, and 1,165 participants developed 3-point MACE, CAD, and stroke, respectively. Skipping breakfast (HR: 1.13, 95% CI: 1.03-1.23) and fast eating (HR: 1.23, 95% CI: 1.04-1.47) were associated with 3-point MACE in the participants overall. Skipping breakfast (HR: 1.23, 95% CI: 1.10-1.37) and fast eating (HR: 1.38, 95% CI: 1.12-1.71) were also associated with 3-point MACE in participants with BMI < 25 kg/m². In contrast, in participants with BMI ≥ 25 kg/m², these associations were not detectable (P value for the interaction between subgroups = 0.09 [skipping breakfast] and 0.03 [fast eating], respectively). The diet behavior is a potential risk factor of incident CVD in Japanese people, particularly in those with BMI < 25 kg/m².

Nonrestorative sleep is a risk factor for metabolic syndrome in the general Japanese population

BACKGROUND

This longitudinal study aimed to investigate the effects of nonrestorative sleep on developing metabolic syndrome (MetS) and related diseases in a general Japanese middle-aged population.

METHODS

Overall, 83,224 adults without MetS (mean age: 51.5 ± 3.5 years) from the Health Insurance Association in Japan were followed up for a maximum of 8 years between 2011 and 2019. The Cox proportional hazard method was used to determine whether nonrestorative sleep, assessed using a single-item question, was significantly associated with the respective development of MetS, obesity, hypertension, diabetes, and dyslipidemia. The MetS criteria were adopted by the Examination Committee for Criteria of Metabolic Syndrome in Japan.

RESULTS

The mean follow-up duration was 6.0 years. The incidence rate of MetS was 50.1 person-years/1,000 during the study period. Data suggested that nonrestorative sleep was associated with MetS (hazard ratio [HR]: 1.12, 95% confidence interval [CI]: 1.08-1.16) and other disorders, such as obesity (HR: 1.07, 95% CI: 1.02-1.12), hypertension (HR: 1.07, 95% CI: 1.04-1.11), and diabetes (HR: 1.07, 95% CI: 1.01-1.12) but not with dyslipidemia (HR: 1.00, 95% CI: 0.97-1.03).

CONCLUSIONS

Nonrestorative sleep is associated with the development of MetS and many of its core components in the middle-aged Japanese population. Therefore, assessing nonrestorative sleep may help identify individuals at a risk of MetS development.

Associations between Various Sleep-Wake-Related Indicators and Nutritional Status in Community-Dwelling Older Adults: The Yilan Study, Taiwan

OBJECTIVES

To elucidate the relationship between various sleep-wake-related indicators and nutritional status.

DESIGN

Cross-sectional study.

SETTING

Community-based survey between 2017 and 2022 in Yilan City, Taiwan.

PARTICIPANTS

1,905 community-dwelling older adults aged ≥65 years.

MEASUREMENTS

Nutritional status was evaluated using the Mini Nutritional Assessment, and participants were classified into normal nutritional status and undernutrition groups. Regarding sleep-wake-related indicators, specific items or component scores of the Pittsburgh Sleep Quality Index were used to assess sleep-wake schedule, subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, presence of sleep disturbances, hypnotic use, and dysfunction in maintaining enthusiasm. The 5-item Athens Insomnia Scale and the Epworth Sleepiness Scale were used to evaluate insomnia and excessive daytime sleepiness, respectively.

RESULTS

Of the 1,905 participants, the mean age was 75.6±7.1, with 52.2% being ≥75 years old, 58.9% were women, and 11.4% had undernutrition. After controlling for covariates, short sleepers were less likely to have undernutrition (OR: 0.63; 95% CI: 0.41-0.97); in contrast, long sleepers were more likely to exhibit undernutrition (OR: 1.52; 95% CI: 1.06-2.17). In addition, poor habitual sleep efficiency (OR:1.69; 95% CI:1.15-2.50), taking hypnotics in the past month (OR: 1.58; 95% CI: 1.12-2.24), and dysfunction in maintaining enthusiasm (OR: 1.93; 95% CI: 1.24-2.99) were associated with increased risk of undernutrition.

CONCLUSIONS

Among older adults, various sleep-wake-related indicators differed in their relationships with nutritional status. Specific sleep-wake disturbances may indicate undernutrition in this population.

Cardiovascular events in insomnia patients with post-traumatic stress disorder

BACKGROUND

Both post-traumatic stress disorder (PTSD) and insomnia are independently associated with a greater risk of cardiovascular mortality. The objective of this study is to determine whether PTSD plus insomnia is associated with a higher risk of major adverse cardiovascular events (MACEs) than either condition alone in a large cohort of veterans.

METHODS

We conducted a retrospective analysis of the national Veterans Health Administration (VHA) electronic medical records covering veterans 18 years or older with the diagnosis of PTSD, insomnia, or both from January 1, 2015, to December 31, 2020. MACE was defined as new-onset myocardial infarction (MI), transient ischemic attack (TIA) or stroke, based on ICD-9 and ICD-10 diagnosis codes from inpatient or outpatient encounters.

RESULTS

A total of 19,080 veterans, 1840 with PTSD plus insomnia and 17,240 with either PTSD or insomnia, were included in the analysis. Baseline mean (SD) age was 46.3 (11.5) years. During median follow-up of 3.9 (interquartile range, 2.4-5.1) years, 206 (1%) veterans developed incident MACE. Cumulative incidence for MI, TIA and/or stroke was larger in veterans with PTSD plus insomnia compared to PTSD and insomnia alone (p=0.008). In a Cox proportional hazards model, PTSD plus insomnia was significantly associated with greater risk of developing MACEs (hazard ratio [HR], 1.44; 95% CI, 1.38-1.50, p=0.01) than either condition after adjusting for multiple covariates including age, gender, smoking, hypertension, depression, and burden of comorbidities.

CONCLUSIONS

This cohort study found that PTSD plus insomnia is a risk factor for MACEs of greater magnitude than PTSD- or insomnia-alone.

Effect of sleep disturbance on biomarkers related to the development of adverse health outcomes: A systematic review of the human literature

Literature suggests that unrestricted and undisturbed sleep is vital for basic human function and performance; however, it is unclear as to what amount of sleep disturbance leads to dysregulation in biomarkers, which may underscore the development of adverse health effects. This systematic review aims to identify the amount of sleep disturbance that contributes to biomarker changes as a potential precursor to the development of adverse health effects. English-language comparative studies available in PubMed, Cochrane Central, EMBASE, and CINAHL databases from 1 January 1980 to 31 July 2021 were searched. Where possible, random-effects meta-analyses were used to examine the effect of sleep disturbances on adverse health effects. The risk of bias of individual studies was assessed using the Cochrane Risk of Bias Tool and the Risk of Bias of Nonrandomised Studies - of Exposures instruments and the certainty of the body of evidence for each outcome was assessed using the Grading of Recommendations Assessment, Development and Evaluation approach. The search identified 92 primary studies reporting on blood pressure, hypertension, heart rate, cardiac arrhythmia, cardiac output, waist circumference, cortisol, adrenaline, noradrenaline, immune system markers, glucose, insulin, cholesterol, and triglyceride levels. Although some meta-analyses suggested there may be an association between sleep disturbances and certain outcomes, the certainty in the evidence was very low due to concerns with risk of bias, inconsistency across exposures, populations, and imprecision in the estimates of effects. Further research is needed to explore the point at which types, levels and duration of sleep disturbances may begin to increase the risk of developing adverse health outcomes to inform and tailor health interventions.

Physiological markers of sleep quality: A scoping review

Understanding the associations between adequate sleep, performance and health outcomes is vital, yet a major limitation in the design and interpretation of studies of sleep and performance is the variability of subjective and objective markers used to assess sleep quality. The aim of this scoping review is to investigate how various physiological signals recorded during sleep or wakefulness relate to objective measures of cognitive or physical performance and subjectively perceived sleep quality to inform conceptual understanding of the elusive, amorphous, and multi-dimensional construct of sleep quality. We also aimed to suggest priorities for future areas of research in sleep quality and performance. We searched six databases ultimately yielding 439 studies after duplicate removal. Sixty-five studies were selected for full review. In general, correlations between objectively measured sleep and objective performance or subjectively assessed sleep quality were weak to moderate. Slow wave sleep was moderately correlated with better performance on tasks of vigilance, motor speed, and executive function as well as better subjective sleep quality and feeling well-rested, suggesting that slow wave sleep may be important for sleep quality and optimal daytime performance. However, these findings were inconsistent across studies. Increased sleep fragmentation was associated with poorer subjective sleep quality in both polysomnographic and actigraphic studies. Studies which simultaneously assessed physiologic sleep measures, performance measures and subjective sleep perception were few, limiting the ability to evaluate correlations between subjective and objective outcomes concurrently in the same individuals. Factors influencing the relationship between sleep quality and performance include circadian variability, sleep inertia, and mismatch between sleep stages studied and outcome measures of choice. Ultimately, the determination of "quality sleep" remains largely subjective and inconsistently quantifiable by current measures. Methods evaluating sleep as a continuous measure rather than traditional sleep stages may provide an intriguing approach to future studies of sleep and performance. Future well-designed studies using novel measures of sleep or multimodal ambulatory wearables assessing the three domains of sleep and performance (objective sleep physiology, objective performance, and subjective sleep quality) are needed to better define quality sleep.

Hyperthyroidism in Graves Disease Causes Sleep Disorders Related to Sympathetic Hypertonia

CONTEXT

It is well known that Graves disease (GD) causes sleep disorders (SDs). However, the characteristics and associated factors of SD and its clinical course post hyperthyroidism normalization remain unclear.

OBJECTIVE

To clarify the characteristics and associated factors of subjective SD and its clinical course after GD treatment.

METHODS

From November 2017 to October 2020, we enrolled 72 participants (22 newly diagnosed with GD with untreated hyperthyroidism, 20 previously diagnosed with GD with normal thyroid function, and 30 normal controls) with no other underlying SD-related diseases. We compared the groups at enrollment and conducted prospective observations after 12 months of treatment on participants with newly diagnosed GD. Main outcome measures were differences and changes in the Pittsburgh Sleep Quality Index (PSQI) global and component sleep quality scores.

RESULTS

PSQI global sleep quality scores (P = .036) and sleep disturbance scores (P = .011) were significantly different among the 3 groups, and were highest in the untreated hyperthyroidism group. Multiple regression analysis demonstrated that free thyroxine level, which was positively correlated with sympathetic tone (ST) as evaluated by pulse rate, and urinary total metanephrines was associated with poorer PSQI global sleep quality scores independently of other factors (P = .006). Prospective observation showed that PSQI global sleep quality scores (P = .018) and sleep disturbance scores (P = .011) significantly improved with thyroid function normalization and ST attenuation.

CONCLUSION

Hyperthyroidism caused by GD augmented ST and exacerbated subjective SD. Normalization of hyperthyroidism caused by GD improved subjective SD.

Association between sleep parameters and longitudinal shortening of telomere length

BACKGROUND

The relationship between sleep parameters and longitudinal shortening of telomere length is unclear. This study aimed to investigate the relationship between sleep parameters and the shortening of leukocyte telomere length (LTL) over a year.

METHODS

Among the participants in the validation cohort of the Korea Brain Aging Study for the Early Diagnosis and Prediction of Alzheimer's Disease, participants who measured both baseline and follow-up (two years later) of LTL were analyzed. They were dichotomized according to the degree of LTL attrition over two years. Clinical characteristics were compared between the faster and slower LTL shortening groups (cut-off points: -0.710 kbp, n = 119 each). Multivariable logistic regression analyses were performed to determine independent relationships between faster shortening of LTL length and sleep parameters.

RESULTS

A total of 238 participants, aged 55-88 years, were included. Participants with faster LTL shortening had a shorter duration of sleep (P = 0.013) and longer sleep latency (P = 0.007). Among the components of the PSQI, subjective measures of sleep quality, sleep latency, sleep duration, and sleep efficiency were significantly worse in participants with faster LTL shortening. Multivariate logistic regression analysis showed that sleep duration (per hour, OR = 0.831, 95% CI = 0.698-0.989), sleep latency (per minute, OR = 1.013, 95% CI = 1.002-1.024), global PSQI score (OR = 1.134, 95% CI = 1.040-1.236), shortest sleep duration (OR = 5.173, 95% CI = 1.563-17.126), and lowest sleep efficiency (OR = 7.351, 95% CI = 1.943-27.946) were independently associated with faster LTL shortening.

CONCLUSIONS

Poor sleep quality, specifically short sleep duration, long sleep latency, and low sleep efficiency were associated with faster longitudinal shortening of LTL.

Obstructive Sleep Apnea and Hypertension: Updates to a Critical Relationship

Purpose of Review

Obstructive sleep apnea (OSA) is an underdiagnosed illness linked to essential hypertension (HTN), resistant hypertension (r-HTN), and cardiovascular disease (CVD). This review provides updates on the epidemiology, pathophysiology, and treatments of OSA-associated HTN.

Recent Findings

Mild sleep apnea increases the risk for HTN. Eighty-nine percent of young patients aged 18–35 with HTN not attributed to secondary causes have underlying OSA. Home sleep studies are noninferior to formal polysomnography for OSA diagnosis. Nocturnal oxygen desaturation rate is positively correlated with HTN severity. Gut microbiome neo-colonization in response to high-fat diet cravings in patients with OSA alters immune function and worsens HTN. Carbonic anhydrase inhibitors and probiotics show newfound potential for OSA-associated HTN treatment. OSA recognition improves hospital outcomes after a STEMI. Hypoxia-inducible factor (HIF) transcription increases in a dose-dependent manner to hypoxia, and HIFs are strongly linked to cancer growth.

Summary

OSA and HTN are comorbid conditions with adversely connected pathophysiology including sympathetic hyperactivity, gut dysbiosis, proinflammation, endothelial damage, rostral fluid shifts, pharyngeal collapse, intravascular fluid retention, nocturnal energy expenditure, and metabolic derangements. The dose–response effect of OSA on HTN severity challenges blood pressure (BP) control, so those with refractory HTN should be screened for OSA.

Causal Roles of Sleep Duration in Osteoporosis and Cardiometabolic Diseases: A Mendelian Randomization Study

Sleep duration suggests some association with osteoporosis and cardiometabolic diseases, but it is unknown if these associations are causal or confounded. In this two-sample Mendelian randomization (MR) study, we included the largest genome-wide association studies (GWASs) associated with sleep duration and the outcome measures of osteoporosis and cardiometabolic diseases. Finally, 25 single nucleotide polymorphisms (SNPs) associated with short sleep duration and 7 SNPs associated with long sleep duration obtained the genome-wide significance (P < 5 × 10^-8) and were used as instrumental variables. Genetic predisposition to short sleep duration was strongly associated with increased risk of coronary artery disease (beta-estimate: 0.199, 95% confidence interval CI: 0.081 to 0.317, standard error SE:0.060, P value = 0.001) and heart failure (beta-estimate: 0.145, 95% CI: 0.025 to 0.264, SE:0.061, P value = 0.017), which were both confirmed by the sensitivity analyses. Both short and long sleep duration may reduce the estimated bone mineral density (eBMD, beta-estimate: -0.086, 95% CI: -0.141 to -0.031, SE:0.028, P value = 0.002 for short sleep duration; beta-estimate: -0.080, 95% CI: -0.120 to -0.041, SE:0.020, P value < 0.0001 for long sleep duration). There was limited evidence of associations between sleep duration and fracture, type 2 diabetes, atrial fibrillation, fasting glucose, fasting insulin, or HbA1c. This study provides robust evidence that short sleep duration is causally associated with high risk of coronary artery disease and heart failure and suggests that short sleep duration should be avoided to prevent these two cardiovascular diseases. Short and long sleep duration show some MR association with reduced eBMD, which indicates that both short and long sleep duration may be prevented to reduce the incidence of osteoporosis.

Insomnia symptoms and subclinical myocardial injury: Data from the Nord-Trøndelag Health (HUNT) study

Insomnia symptoms are associated with increased risk of heart failure (HF) and cardiovascular (CV) mortality. We hypothesised that insomnia symptoms are cross-sectionally associated with increased cardiac troponin I (cTnI), a biomarker of subclinical myocardial injury, and that phenotyping by insomnia symptoms and cTnI enhances longitudinal risk stratification in the general population. In a population-based study, cTnI was measured in 8,398 participants (median age 49 years, 55% women), who had answered questionnaires regarding insomnia symptoms. Association between cTnI and insomnia symptoms was assessed by linear regression analysis for each response category of a sleep questionnaire. Insomnia symptoms were defined as having difficulty falling asleep almost every night, difficulty maintaining sleep almost every night, and/or non-restorative sleep once a week or more. The primary outcome measure was a composite endpoint of CV mortality or first admission for HF. In all, 844 participants reported insomnia symptoms, 585 (69%) were women. Those with insomnia symptoms had marginally, but significantly higher median cTnI than those without insomnia symptoms, (median [interquartile range] 3.4 [2.4-5.2] ng/L versus 3.2 [2.2-4.9] ng/L; p = .014), but there was no association between any insomnia symptom and cTnI in unadjusted linear regression models (β 0.06, 95% confidence interval [CI] -0.01 to 0.12). In adjusted analyses, participants with insomnia symptoms and increased cTnI were at increased risk of the composite endpoint (hazard ratio 1.71, 95% CI 1.04-2.79) compared to participants with insomnia symptoms and low cTnI. In the general population, insomnia symptoms are not associated with biochemical evidence of subclinical myocardial injury.

Improved sleep efficiency is associated with reduced cardio-metabolic risk: Findings from the MODERN trial

Poor sleep increases cardio-metabolic risk, but limited information on the impact of sleep for the improvement of cardio-metabolic health exists. This analysis examined the impact of sleep on a health and lifestyle modification programme to reduce cardio-metabolic disease risk factors. Secondary analysis of the MODERN randomised controlled trial to reduce cardio-metabolic risk was undertaken at baseline and 24-month follow-up. Participants aged 40-70 years (n = 121) with three or more cardio-metabolic risk factors were randomised to a health and lifestyle modification intervention (n = 59) or usual care (n = 62), and underwent 7 day/night actigraphy to assess total sleep time, sleep efficiency (%), number of awakenings/night and physical activity levels. Blood pressure, blood lipid and glycaemic levels, anthropometric and diet measures were collected. The mean age was 59 ± 7 years and 37% were male. Baseline sleep measures were not different between groups. At the 24-month follow-up, both groups showed improvements in cardio-metabolic risk factors, albeit the change in blood pressure was greater in the intervention compared with the usual care group (systolic blood pressure: -11 versus -4 mmHg, p = .014). There were no differences between groups for diet, physical activity or sleep parameters. An increase in sleep efficiency was independently associated with lower systolic blood pressure (β = -2.117, p = .002) and higher high-density lipoprotein levels (β = 0.040, p = .033); an increase in total sleep time was associated with lower low-density lipoprotein levels (β = -0.003, p = .038) at 24 months. Overall, improvement in sleep quality over time was beneficial to reduce blood pressure and lipid levels. These findings highlight sleep as a potential target to reduce cardio-metabolic risk.

Causal associations of short and long sleep durations with 12 cardiovascular diseases: linear and nonlinear Mendelian randomization analyses in UK Biobank

AIMS

Observational studies have suggested strong associations between sleep duration and many cardiovascular diseases (CVDs), but causal inferences have not been confirmed. We aimed to determine the causal associations between genetically predicted sleep duration and 12 CVDs using both linear and nonlinear Mendelian randomization (MR) designs.

METHODS AND RESULTS

Genetic variants associated with continuous, short (≤6 h) and long (≥9 h) sleep durations were used to examine the causal associations with 12 CVDs among 404 044 UK Biobank participants of White British ancestry. Linear MR analyses showed that genetically predicted sleep duration was negatively associated with arterial hypertension, atrial fibrillation, pulmonary embolism, and chronic ischaemic heart disease after correcting for multiple tests (P < 0.001). Nonlinear MR analyses demonstrated nonlinearity (L-shaped associations) between genetically predicted sleep duration and four CVDs, including arterial hypertension, chronic ischaemic heart disease, coronary artery disease, and myocardial infarction. Complementary analyses provided confirmative evidence of the adverse effects of genetically predicted short sleep duration on the risks of 5 out of the 12 CVDs, including arterial hypertension, pulmonary embolism, coronary artery disease, myocardial infarction, and chronic ischaemic heart disease (P < 0.001), and suggestive evidence for atrial fibrillation (P < 0.05). However, genetically predicted long sleep duration was not associated with any CVD.

CONCLUSION

This study suggests that genetically predicted short sleep duration is a potential causal risk factor of several CVDs, while genetically predicted long sleep duration is unlikely to be a causal risk factor for most CVDs.

Associations of sleep phenotypes with severe intentional self-harm: a prospective analysis of the UK Biobank cohort

STUDY OBJECTIVES

We aimed to investigate the prospective associations of sleep phenotypes with severe intentional self-harm (ISH) in middle-aged and older adults.

METHODS

A total of 499,159 participants (mean age: 56.55 ± 8.09 years; female: 54.4%) were recruited from the UK Biobank between 2006 and 2010 with follow-up until February 2016 in this population-based prospective study. Severe ISH was based on hospital inpatient records or a death cause of ICD-10 codes X60-X84. Patients with hospitalized diagnosis of severe ISH before the initial assessment were excluded. Sleep phenotypes, including sleep duration, chronotype, insomnia, sleepiness, and napping, were assessed at the initial assessments. Cox regression analysis was used to estimate temporal associations between sleep phenotypes and future risk of severe ISH.

RESULTS

During a follow-up period of 7.04 years (SD: 0.88), 1,219 participants experienced the first hospitalization or death related to severe ISH. After adjusting for demographics, substance use, medical diseases, mental disorders, and other sleep phenotypes, short sleep duration (HR: 1.50, 95% CI: 1.23-1.83, P < .001), long sleep duration (HR: 1.56, 95% CI: 1.15-2.12, P = .004), and insomnia (usually: HR: 1.57, 95% CI: 1.31-1.89, P < .001) were significantly associated with severe ISH. Sensitivity analyses excluding participants with mental disorders preceding severe ISH yielded similar results.

CONCLUSION

The current study provides the empirical evidence of the independent prediction of sleep phenotypes, mainly insomnia, short and long sleep duration, for the future risk of severe ISH among middle-aged and older adults.

Sleeping Difficulty and Subjective Short Sleep Duration are Associated with Serum N-terminal Pro-brain Natriuretic Peptide Levels in the Elderly Population

Objective It is well known that poor sleep increases the risk of heart failure (HF). However, the underlying mechanisms remain unclear. In this study, we investigated the association of poor sleep with hemodynamic stress on the left ventricle, which was a key factor for the development of HF in elderly individuals. Methods A total of 2,301 participants (≥65 years old) without cardiac disease were enrolled in this cross-sectional analysis. We evaluated the subjective sleep quality, sleeping difficulty, subjective sleep duration, use of sleeping pills, and daytime dysfunction using the Pittsburgh Sleep Quality Index, a 19-item self-reported questionnaire. We assessed serum N-terminal pro-brain natriuretic peptide (NT-proBNP) as a marker of hemodynamic stress on the left ventricle, and we defined high NT-proBNP as a serum NT-proBNP level ≥ 125 pg/mL. Results Sleeping difficulty was significantly associated with high NT-proBNP levels [odds ratio (OR), 1.46; 95% confidence interval (CI), 1.16-1.85; p<0.005]. A subjective short sleep duration was also significantly associated with high NT-proBNP levels (OR, 1.69; 95% CI, 1.03-2.75; p<0.05). A subjective poor sleep quality, the use of sleeping pills, and daytime dysfunction were not associated with serum NT-proBNP levels. All data were adjusted for the age, sex, body mass index, serum hemoglobin concentration, serum creatinine level, systolic blood pressure, diastolic blood pressure, and use of antihypertensive medications. Conclusion Poor sleep was associated with high hemodynamic stress to the left ventricle in elderly population.

Long sleep duration and risk of increased arterial stiffness in a Chinese population

To examine the relationship between self-reported sleep duration and arterial stiffness in a large Chinese population from Kailuan.From July 2010 to December 2015, a total of 17,018 participants aged 18 to 98 years were enrolled after excluding those with a history of cerebrovascular events and coronary artery disease. Participants were divided into 5 categories according to self-reported night sleep duration: ≤5.0, 6.0, 7 (ref), 8, and ≥9.0 hours. A brachial-ankle pulse wave velocity ≥1400 cm/s was considered to represent arterial stiffness. Multivariate logistic regression models were used to calculate the odds ratio (OR) and confidence interval (CI) for arterial stiffness according to the sleep duration.Using 7 hours of sleep as the reference group, the multivariable adjusted ORs (95% CI) for arterial stiffness were 1.00 (0.87-1.16), 1.00 (0.90-1.11), 1.0 (ref), 1.03 (0.93-1.14), and 1.48 (1.05-2.08) from the lowest to highest category of sleep duration, respectively. Secondary analysis showed no evidence of interactions between sleep duration and age/sex on the risk of arterial stiffness (P-interaction = .390/.198).A long night sleep duration was associated with increased arterial stiffness.

Sleep and Obesity: Mechanisms of Association

Epidemiologic studies demonstrate that both prolonged and reduced sleep duration is associated with increased risk of excessive weight and obesity. The aim of the review was to analyze probable mechanisms of association of sleep duration and obesity elucidated in current scientific literature. Several proposed mechanisms of such an association exist: an imbalance of appetite regulating hormones resulting from decreased sleep duration; fatigue or decreased activity during the daytime, leading to sedentary behavior with decreased energy expenditure; changes in eating behavior with increased daily calorie intake. The article gives a comprehensive review of factors, mediating the association of sleep duration and obesity (age, gender, ethnic origin), studies of neurohormonal regulation of sleep in association with obesity (the influence of sleep duration on thermoregulation, appetite center – increased grelin-to-leptin ratio); the relationship of sleep with growth hormone and insulin-like growth factor-1, with hypothalamic-pituitary-adrenal axis, and non-hormonal factors, stimulating food intake. Data indicating that increased sleep duration is often associated with decreased sleep quality are presented. Besides traditional risk factors – unhealthy diet and decreased physical exercise, specific attention should be given to the problems, associated with sleep disorders to increase the efficacy of treatment and prevention of obesity.

Association of self-reported sleep duration and quality with BaPWV levels in hypertensive patients

The association between sleep conditions and arterial stiffness remains inconclusive. We aimed to investigate the relationship of sleep duration and quality with brachial-ankle pulse-wave velocity (baPWV) in hypertensive patients. A total of 14,485 hypertensive adults were included in this cross-sectional analysis. Information about sleep duration and quality was obtained via questionnaire. A baPWV level ≥1800 cm/s was defined as indicative of arterial stiffness. Compared with participants with a sleep duration <8 h per day, participants with a sleep duration ≥8 h per day had a significantly higher baPWV level (β = 13.7 cm/s; 95% CI: 3.9, 23.5) and a nonsignificantly higher prevalence of arterial stiffness (39.7% vs. 33.0%; OR, 1.08; 95% CI: 0.99-1.19). Similarly, compared with participants with good or medium sleep quality, participants with poor sleep quality had a significantly higher baPWV level (β = 16.3 cm/s; 95% CI: 0.1, 32.6) and a nonsignificantly greater prevalence of arterial stiffness (36.6% vs. 35.3%; OR, 1.13; 95% CI: 0.97-1.32). When sleep duration and quality were examined jointly, participants with a sleep duration ≥8 h and/or poor sleep quality had a significantly higher baPWV level (β = 14.4 cm/s; 95% CI: 5.3, 23.4) and a greater prevalence of arterial stiffness (38.8% vs. 32.7%; OR, 1.10; 95% CI: 1.01-1.20) than those with a sleep duration <8 h and good/medium sleep quality. In summary, among hypertensive patients, a longer sleep duration (≥8 h per day) and poor sleep quality were associated with higher baPWV levels and a higher prevalence of arterial stiffness.

The relationship between sleep problems and cortisol in people with type 2 diabetes

BACKGROUND

Sleep problems are linked with negative health outcomes, including coronary heart disease. Neuroendocrine dysfunction has been associated with sleep problems and may be a pathway linking sleep and ill health. Dysregulated cortisol output has observed in people with type 2 diabetes (T2D), though little is known about the links between sleep and cortisol in this population at high risk of coronary disease.

METHOD

This study investigated the association between sleep problems and cortisol over the course of an ordinary day and in response to acute laboratory stress in a sample of 129 individuals with T2D. Sleep problems were assessed using the Jenkins sleep problems questionnaire. Mental stress was induced using two five-minute laboratory stress tasks: a mirror-tracing task and the Stroop color-word interference task.

RESULTS

Sleep problems were positively associated with daily cortisol area under the curve (B = 17.051, C.I. = 6.547 to 27.554, p = 0.002) adjusting for age, sex, marital status, education, household income, body mass index and smoking; suggesting that those with greater sleep problems had greater cortisol concentrations over the course of an ordinary day. Participants reporting greater sleep problems also had raised evening cortisol levels (B = 0.96, C.I. = 0.176 to 1.746, p = 0.017) in adjusted models. In the laboratory sleep problems were negatively associated with cortisol immediately post-task (B = -0.030, C.I. = -0.059 to 0.000, p = 0.048) and 45 minutes post-task (B = -0.037, C.I. = -0.072 to -0.002, p = 0.039) in fully adjusted models; indicating that those who experienced greater sleep problems had lower cortisol concentrations after stress.

CONCLUSIONS

Sleep problems were associated with disturbances in cortisol responses to stress, as well as changes diurnal cortisol output in people with T2D. Further research is needed to assess if neuroendocrine disturbance increases the risk of cardiovascular disease in this population.

Sleep quantity and quality and cardiometabolic risk factors in Indigenous Australians

Poor sleep is associated with increased risk of cardiovascular disease (CVD). Indigenous Australians have 1.3 times higher risk of CVD compared to non-indigenous Australians. However, there are limited data describing sleep problems and cardiometabolic risk in this population. This study aimed to investigate sleep quantity and quality in indigenous Australians and assess its association with cardiometabolic risk. Two hundred and forty-five indigenous Australians aged > 18 years were recruited via convenience sampling from communities in the Northern Territory and Queensland. Sleep quantity and quality was assessed subjectively with questionnaires including the Epworth Sleepiness Scale. In a sub-population (n = 46), objective sleep assessment was performed over three nights of actigraphy. Cardiometabolic risk measures included glycated haemoglobin, lipids, anthropometric measurements and sitting blood pressure. Sleep duration measured subjectively and objectively averaged 7.5 ± 2.0 hr/night; however, over one-third of participants (self-report 35%; actigraphy 39%) obtained < 7 hr/night. Overall, more than a third of participants experienced poor-quality sleep, with 27% reporting severe daytime sleepiness (ESS score > 10) and a high number of objectively measured awakenings/night (6 ± 4). Short sleep duration (<6 hr/night) measured both subjectively and objectively was an independent predictor of diastolic (β = 5.37, p = .038) and systolic blood pressure (β = 14.30, p = .048). More objectively measured night-time awakenings were associated with increased glycated haemoglobin levels (β = 0.07, p = .020) and greater sleep fragmentation was associated with lower high-density lipoprotein levels (β = -0.01, p = .025). A large proportion of indigenous Australians experienced short sleep durations and had significant sleep disruption. Poor sleep quantity and quality may contribute to heightened cardiometabolic risk in this population.

Sleep Extension Increases the Effect of Caloric Restriction Over Body Weight and Improves the Chronic Low-Grade Inflammation in Adolescents With Obesity

PURPOSE

Diminution of sleep may be associated with obesity. However, evidence that extending sleep duration might favor weight loss is insufficient. The aim of this study was to compare the effect of dietary restriction with or without prescription of sleep extension on weight loss in adolescents with obesity.

METHODS

A total of 52 adolescents with obesity (24 males and 28 females) received a diet with 500 calories restriction, randomly allocated to groups without (n = 27) and with sleep extension (n = 25) for 4 weeks. We collected data on anthropometry, caloric intake, and self-reported sleep diaries. Serum interleukin 6, tumor necrosis factor α, leptin, and insulin levels were quantified by enzyme-linked immunosorbent assay. Cortisol and 6-sulfatoxymelatonin excretions were measured in the first urine collection in the morning by liquid chromatography-mass spectrometry. Measurements were carried out at baseline and at the end of the intervention.

RESULTS

After diet, weight decreased in both groups. Sleep extension, improved weight loss (p < .00001), and waist girth reduction (p = .00003), with diminution of insulin (p = .002) and interleukin 6 levels (p = .02). Caloric restriction was less effective in adolescent females. No differences in cortisol or 6-sulfatoxymelatonin excretion were found.

CONCLUSIONS

A sleep extension favors weight loss in adolescents under caloric restriction and improves inflammation and metabolic conditions, thus supporting a possible additional benefit to diet in the treatment of obesity in adolescents.

Relationship between Cortisol Changes during the Night and Subjective and Objective Sleep Quality in Healthy Older People

The aim of this study was to investigate whether the nighttime cortisol release was associated with subjective and objective sleep quality and the discrepancy between them. Forty-five healthy older adults (age range from 56 to 75 years) collected salivary samples immediately before sleep and immediately after awakening on two consecutive nights. Actigraphy was used to assess objective sleep quality and quantity. A sleep diary was used to assess subjective sleep quality. Linear mixed models were performed using subjective and objective sleep quality data from 76 nights to investigate between-subject associations. We observed that larger changes in cortisol levels between sleep onset and awakening, reflecting a healthier circadian rhythm of the Hypothalamic-Pituitary-Adrenal (HPA) axis, were associated with better subjective sleep quality, but not with objective sleep quality. Moreover, smaller changes in nighttime cortisol were associated with lower subjective sleep quality relative to objective sleep quality. All these results were observed even after controlling for important confounders such as sleep quantity, age, sex, subjective socioeconomic status, stress perception, depression, physical activity, and adherence to the salivary sampling protocol. This study demonstrates that subjective sleep quality in older people may be explained, to some extent, by the activity of the HPA axis.

Breakfast skipping is associated with persistently increased arterial stiffness in patients with type 2 diabetes

OBJECTIVE

While certain lifestyle habits may be associated with arterial stiffness, there is limited literature investigating the relationship between lifestyle habits and longitudinal changes in arterial stiffness in patients with type 2 diabetes mellitus (T2DM). This is an exploratory study to determine whether lifestyle habits, in addition to conventional atherosclerotic risk factors, are associated with increased arterial stiffness.

RESEARCH DESIGN AND METHODS

The study participants comprised 734 Japanese outpatients with T2DM and no history of apparent cardiovascular diseases. Lifestyle habits were analyzed using self-reported questionnaires, and brachial-ankle pulse wave velocity (baPWV) was measured at baseline, and at years 2 and 5. A multivariable linear mixed-effects model was used to determine the predictive value of lifestyle habits and possible atherosclerotic risk factors for longitudinal change in baPWV.

RESULTS

Over 5 years of follow-up, baPWV values significantly increased. In a multivariable linear mixed-effects model that adjusted for age and gender, a low frequency of breakfast intake was significantly associated with persistently high baPWV, independently of other lifestyle habits. Furthermore, in a multivariable linear mixed-effects model that included both lifestyle habits and possible atherosclerotic risk factors, a low frequency of breakfast intake remained the only independent predictive factor for persistently high baPWV. Subjects who ate breakfast less frequently tended to have additional unhealthy lifestyle habits and atherosclerotic risk factors.

CONCLUSIONS

Our analyses suggest that breakfast skipping is an independent lifestyle habit that is associated with persistently increased arterial stiffness in patients with T2DM.

TRIAL REGISTRATION NUMBER

UMIN000010932.

Acute and Chronic Insomnia: What Has Time and/or Hyperarousal Got to Do with It?

Nearly one-third of the population reports new onset or acute insomnia in a given year. Similarly, it is estimated that approximately 10% of the population endorses sleep initiation and maintenance problems consistent with diagnostic criteria for chronic insomnia. For decades, acute and chronic insomnia have been considered variations of the same condition or disorder, only really differentiated in terms of chronicity of symptoms (days/weeks versus months). Whether or not acute and chronic insomnia are part of the same phenomena is an important question, one that has yet to be empirically evaluated. The goal of the present theoretical review was to summarize the definitions of acute and chronic insomnia and discuss the role that hyperarousal may have in explaining how the pathophysiology of acute and chronic insomnia is likely different (i.e., what biopsychological factors precipitate and/or perpetuate acute insomnia, chronic insomnia, or both?).

Endothelial Dysfunction is Related to Glycemic Variability and Quality and Duration of Sleep in Adults With Type 1 Diabetes

BACKGROUND

Elevated cardiovascular disease risk in people with type 1 diabetes (T1DM) is incompletely understood. Glycemic control, glycemic variability, and sleep quality and duration may relate to cardiovascular disease risk in this population via endothelial dysfunction.

OBJECTIVE

The aim of this study was to examine relationships among glycemic control, glycemic variability, sleep quality and duration, and endothelial function in adults with T1DM.

METHODS

Endothelial function was measured using flow-mediated dilation. Glycemic control and glycemic variability were measured using A1C and a continuous glucose monitor, respectively; sleep quality and duration were measured with the Pittsburgh Sleep Quality Index.

RESULTS

Twenty subjects were recruited. Reduced flow-mediated dilation and higher glucose levels were associated with poorer sleep quality (r = -0.51, P = .01; r = 0.52, P = .03). Subjects with shorter sleep duration had greater glycemic variability.

CONCLUSIONS

Endothelial dysfunction (a precursor to cardiovascular disease) relates to glycemic control, glycemic variability, and sleep quality in T1DM.

Interplay of Objective Sleep Duration and Cardiovascular and Cerebrovascular Diseases on Cause-Specific Mortality

Background Cardiovascular and cerebrovascular diseases (CBVDs) and cancer are leading causes of death. Short sleep is a potential contributor to health; however, its role in predicting mortality associated with cardiometabolic risk factors (CMRs) and CBVD remains poorly understood. We tested whether objective short sleep duration increases the risk of mortality associated with CMRs and CBVD. Methods and Results A total of 1654 adults (aged 20-74 years) from the Penn State Adult Cohort (47.5 years, 52.5% women, and 89.8% white) whose cause of death was determined after 19.2 years (5.2 years). CMR was defined as stage 2 hypertension and/or type 2 diabetes mellitus on the basis of blood pressure and glucose levels or a report of diagnosis or treatment for these conditions. CBVD was defined as a report of diagnosis or treatment for heart disease and/or stroke. Objective short sleep duration was defined as polysomnographic total sleep time <6 hours. Cox proportional hazard models estimated multivariable-adjusted hazard ratios (HRs) and 95% CIs. Risk of all-cause mortality associated with CMR or CBVD was significantly modified by objective sleep duration (P<0.05), and it was significantly higher in subjects who slept <6 hours (HR, 2.14 [95% CI, 1.52-3.02] and HR, 3.17 [95% CI=2.16-4.65], respectively). In subjects who slept <6 hours, CMR was associated with a 1.83 higher (95% CI, 1.07-3.13) risk of CBVD mortality and CBVD with a 2.92 higher (95% CI, 1.28-6.65) risk of cancer mortality. In subjects who slept ≥6 hours, CMR was not significantly associated with CBVD mortality (HR, 1.35; 95% CI, 0.70-2.63) nor was CBVD significantly associated with cancer mortality (HR, 0.55; 95% CI, 0.18-1.64). Conclusions Objective short sleep duration predicts the all-cause mortality prognosis of middle-aged adults with CMR and the cancer-specific mortality prognosis of those with CBVD.

Bedtime Procrastination, Sleep-Related Behaviors, and Demographic Factors in an Online Survey on a Polish Sample

The sufficient length and good quality of night sleep play a vital role in maintaining health, well-being and effective functioning. Nevertheless, an increase in the prevalence of sleep deprivation can be observed recently. The concept of bedtime procrastination, defined as going to bed later than intended, has been proposed to explain one of the psychological determinants of sleep deficiency. To investigate the prevalence of bedtime procrastination among Poles we carried out a Polish adaptation of the Bedtime Procrastination Scale (BPS), a self-report questionnaire for measuring the tendency to voluntarily postpone going to bed in the absence of any external circumstances for doing so. The aim of the research was to determine the main psychometric properties of the Polish version of the BPS. We also aimed to identify the relationships between bedtime procrastination and selected demographic variables in the Polish sample, and to examine the impact of bedtime procrastination on self-reported sleep outcomes. The data obtained from online surveys conducted on two Polish samples were analyzed, including demographic factors, self-reported sleep outcomes, and responses to items of the BPS. The Polish version of the BPS has a unifactorial structure like the original version. It also exhibits satisfactory internal consistency and moderate temporal stability in a 10-week retest study. BPS scores were not significantly related to the place of residence, the highest completed level of education, living with a spouse or partner, and living with children. Scores in BPS slightly decreased with age and females scored higher on BPS than males. Higher BPS scores were obtained for a group of students in comparison to a group of subjects who were not students, and lower BPS scores were found in working respondents in comparison to respondents who were not working. BPS scores correlate negatively with sleep length on workdays and a feeling of sleep sufficiency, and positively with sleep length on weekdays relative to workdays, sleeping later than one would like, and a feeling of fatigue. Several relationships between self-reported sleep outcomes and demographic variables were also identified.

Sleep influences on cardio-metabolic health in Indigenous populations

Indigenous populations continue to be among the world's most marginalized population groups. Studies in Indigenous populations from high income countries (including the United States, Canada, Australia, and New Zealand) indicate increased risk of sleep disorders compared to non-Indigenous populations. Poor sleep, whether it be short sleep duration or fragmented sleep, is a well-established risk factor for cardio-metabolic diseases. Given the implications, targeted improvement of poor sleep may be beneficial for the health and well-being of Indigenous people. In this narrative review, we will: (1) discuss the effects of sleep on the cardio-metabolic processes; (2) examine sleep in Indigenous populations; (3) review the association between sleep and cardio-metabolic risk in Indigenous populations; and (4) review the potential role of sleep in cardiovascular disease risk detection and interventions to improve sleep and cardio-metabolic health in Indigenous people. In particular, this review highlights that the assessment of sleep quality and quantity may be a beneficial step toward identifying Indigenous people at risk of cardio-metabolic diseases and may represent a key intervention target to improve cardio-metabolic outcomes.

Gender differences in the associations between insomnia and glycemic control in patients with type 2 diabetes: a cross-sectional study

STUDY OBJECTIVES

Insomnia is associated with insulin resistance and type 2 diabetes (T2D) in the general population. However, the associations between insomnia and glycemic control in T2D population are not consistently reported. In this study, we aimed to examine the associations between insomnia and glycemic control, and gender differences in these associations among Hong Kong Chinese patients with T2D.

METHODS

This was a cross-sectional study involving T2D patients recruited from the Hong Kong Diabetes Registry between July 2010 and June 2015. Glycemic control was estimated by fasting plasma glucose (FPG) and glycated hemoglobin (HbA1c). Participants with the Insomnia Severity Index score > 14 were considered as having insomnia.

RESULTS

A total of 3753 patients were recruited. Compared with patients without insomnia, patients with insomnia had higher levels of FPG and HbA1c. After adjustment for potential confounding factors, insomnia was associated with higher FPG and HbA1c in the entire cohort. There were significant interactions between insomnia and gender for FPG (p = 0.001) and HbA1c (p = 0.025) in the full model. Subgroup analyses found that men with insomnia had higher FPG [8.23 (7.85-8.61) mmol/L versus 7.50 (7.39-7.61) mmol/L, p < 0.001] and HbA1c [7.79 (7.57-8.02)% versus 7.45 (7.39-7.52)%, p = 0.005] than men without insomnia after adjusted for confounding factors, whereas such difference was not observed in women.

CONCLUSIONS

T2D patients with insomnia had worse glycemic control than the patients without insomnia. The associations were particularly pronounced in men.

Inter-correlations Among Clinical, Metabolic, and Biochemical Parameters and Their Predictive Value in Healthy and Overtrained Male Athletes: The EROS-CORRELATIONS Study

Objectives: The Endocrine and Metabolic Responses on Overtraining Syndrome (EROS) study identified multiple hormonal and metabolic conditioning processes in athletes, and underlying mechanisms and biomarkers of overtraining syndrome (OTS). The present study's objective was to reveal independent predictors and linear correlations among the parameters evaluated in the EROS study to predict clinical, metabolic, and biochemical behaviors in healthy and OTS-affected male athletes. Methods: We used multivariate linear regression and linear correlation to analyze possible combinations of the 38 parameters evaluated in the EROS study that revealed significant differences between healthy and OTS-affected athletes. Results: The testosterone-to-estradiol (T:E) ratio predicted the measured-to-predicted basal metabolic rate (BMR) ratio; the T:E ratio and total testosterone level were inversely predicted by fat mass and estradiol was not predicted by any of the non-modifiable parameters. Early and late growth hormone, cortisol, and prolactin responses to an insulin tolerance test (ITT) were strongly correlated. Hormonal responses to the ITT were positively correlated with fat oxidation, predicted-to-measured BMR ratio, muscle mass, and vigor, and inversely correlated with fat mass and fatigue. Salivary cortisol 30 min after awakening and the T:E ratio were inversely correlated with fatigue. Tension was inversely correlated with libido and directly correlated with body fat. The predicted-to-measured BMR ratio was correlated with muscle mass and body water, while fat oxidation was directly correlated with muscle mass and inversely correlated with fat mass. Muscle mass was directly correlated with body water, and extracellular water was directly correlated with body fat and inversely correlated with body water and muscle mass. Conclusions: Hypothalamic-pituitary responses to stimulation were diffuse and indistinguishable between the different axes. A late hormonal response to stimulation, increased cortisol after awakening, and the T:E ratio were correlated with vigor and fatigue. The T:E ratio was also correlated with body metabolism and composition, testosterone was predicted by fat mass, and estradiol predicted anger. Hydration status was inversely correlated with edema, and inter-correlations were found among fat oxidation, hydration, and body fat.

Actigraphy-based sleep characteristics and aortic stiffness: the Multi-Ethnic Study of Atherosclerosis

The study aimed to examine the association between objective estimates of sleep duration and quality and aortic stiffness while accounting for the potential confounding effect of sleep-disordered breathing. Participants were part of the Multi-Ethnic Study of Atherosclerosis Sleep study. Sleep duration and quality were assessed by 7-day wrist actigraphy, sleep-disordered breathing by home polysomnography, and aortic stiffness by magnetic resonance imaging-based aortic pulse wave velocity (aPWV), ascending and descending aorta distensibility. Aortic stiffness of participants with "normal" sleep duration (6-8 hours) were compared with those of "short" (<6 hours) and "long" sleep duration (>8 hours) adjusting for common cardiovascular risk factors and apnea-hypopnea index. The sample consisted of 908 participants (mean age 68.4 ± 9.1 years, 55.3% female). There was a significant linear trend of increased aPWV across short (n = 252), normal (n = 552), and long sleep durations (n = 104) (P for trend = .008). Multivariable analysis showed that people with short sleep duration had 0.94 m/s lower aPWV (95% CI: -1.54, -0.35), compared with those with normal sleep duration. In this ethnically diverse community cohort, habitual short sleep duration as estimated by actigraphy was associated with lower aortic stiffness.

Association of sleep problems with neuroendocrine hormones and coagulation factors in patients with acute myocardial infarction

Background

Obstructive sleep apnea (OSA) and insomnia are frequent sleep problems that are associated with poor prognosis in patients with coronary heart disease. The mechanisms linking poor sleep with an increased cardiovascular risk are incompletely understood. We examined whether a high risk of OSA as well as insomnia symptoms are associated with neuroendocrine hormones and coagulation factors in patients admitted with acute myocardial infarction.

Methods

We assessed 190 patients (mean age 60 years, 83% men) in terms of OSA risk (STOP screening tool for the assessment of high vs. low OSA risk) and severity of insomnia symptoms (Jenkins Sleep Scale for the assessment of subjective sleep difficulties) within 48 h of an acute coronary intervention. Circulating concentrations of epinephrine, norepinephrine, cortisol, fibrinogen, D-dimer, and von Willebrand factor were measured the next morning. The association of OSA risk and insomnia symptoms with neuroendocrine hormones and coagulation factors was computed using multivariate models adjusting for demographic factors, health behaviors, somatic and psychiatric comorbidities, cardiac disease-related variables, and OSA risk in the model for insomnia symptoms, respectively, for insomnia symptoms in the model for OSA risk.

Results

High OSA risk was identified in 41% of patients and clinically relevant insomnia symptoms were reported by 27% of patients. Compared to those with low OSA risk, patients with high OSA risk had lower levels of epinephrine (p = 0.015), norepinephrine (p = 0.049) and cortisol (p = 0.001). More severe insomnia symptoms were associated with higher levels of fibrinogen (p = 0.037), driven by difficulties initiating sleep, and with lower levels of norepinephrine (p = 0.024), driven by difficulties maintaining sleep.

Conclusions

In patients with acute myocardial infarction, sleep problems are associated with neuroendocrine hormones and coagulation activity. The pattern of these relationships is not uniform for patients with a high risk of OSA and those with insomnia symptoms, and whether they contribute to adverse cardiovascular outcomes needs to be established.

Trial registration

ClinicalTrials.gov NCT01781247.

Sleep problems in adults with autism spectrum disorder and intellectual disability

Sleep problems (SP) are recognized as a common comorbid condition in autism spectrum disorder (ASD) and can influence core autism symptoms and mental and physical health. SPs can be lifelong and have been reported that adults on the autistic spectrum with and without intellectual disability (ID) present SPs (longer sleep latency, frequent night awakenings, and circadian rhythm sleep-wake disorders). A prospective, objective sleep study was conducted in 41 adults with ASD (33 ± 6 years old) and ID and 51 typically developing adults (33 ± 5 years old) using ambulatory circadian monitoring (ACM) recording wrist temperature, motor activity, body position, sleep, and light intensity. The findings indicated that individuals with ASD presented sleep difficulties including low sleep efficiency, prolonged sleep latency and increased number and length of night awakenings, together with daily sedentary behavior, and increased nocturnal activity. Furthermore, indications of an advanced sleep-wake phase disorder were found in these autistic adults. Examining sleep and markers of the circadian system showed significant differences between adults with ASD and ID and an age-matched, healthy adult population. The sleep disturbances described for this sample of adults with ASD and ID are similar to those of already described for adults with ASD without ID; their relationship with intellectual ability should be further studied. Improving knowledge of sleep patterns in ASD adults with ID might help to designed targeted interventions to improve their functioning and reduce family stress. Autism Research 2019, 12: 66-79. © 2018 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: SPs are very frequent in autism from childhood to adulthood. We recorded sleep with a watch-like device in adults with autism and ID and compared sleep patterns with nonautistic volunteers. Results showed poorer sleep conditions in adults with autism (increased sleep latency and number/length of night awakenings) that resulted in decreased sleep efficiency. Increasing knowledge of the SPs in adults on the autism spectrum will allow to improve their and their families' quality of life.

Altered ultradian cortisol rhythmicity as a potential neurobiologic substrate for chronic insomnia

Chronic insomnia is highly prevalent and associated with significant morbidity (i.e., confers risk for multiple psychiatric and medical disorders, such as depression and hypertension). Therefore, it is essential to identify factors that perpetuate this disorder. One candidate factor in the neurobiology of chronic insomnia is hypothalamic-pituitary-adrenal-axis dysregulation, and in particular, alterations in circadian cortisol rhythmicity. Cortisol secretory patterns, however, fluctuate with both a circadian and an ultradian rhythm (i.e., pulses every 60-120 min). Ultradian cortisol pulses are thought to be involved in the maintenance of wakefulness during the day and their relative absence at night may allow for the consolidation of sleep and/or shorter nocturnal awakenings. It is possible that the wakefulness that occurs in chronic insomnia may be associated with the aberrant occurrence of cortisol pulses at night. While cortisol pulses naturally occur with transient awakenings, it may also be the case that cortisol pulsatility becomes a conditioned phenomenon that predisposes one to awaken and/or experience prolonged nocturnal awakenings. The current review summarizes the literature on cortisol rhythmicity in subjects with chronic insomnia, and proffers the suggestion that it may be abnormalities in the ultradian rather than circadian cortisol that is associated with the pathophysiology of insomnia.