Insomnia with objective short sleep duration is associated with deficits in neuropsychological performance: a general population study

Association between sleep duration and serum neurofilament light chain levels among adults in the United States

Background

Neurofilaments are neuron specific skeleton proteins maintaining axon transduction speed, leaked into cerebrospinal fluid and serum after axonal injury or neuron death. Sleep duration change has long related to many health issues but lack laboratory examination.

Methods

This study enrolled total 10,175 participants from 2013 to 2014 National Health and Nutrition Examination Survey and used a multi-variable linear model to analyze the relationship between sleep duration and serum neurofilament light chain (sNfL) level.

Results

There was a fixed relationship between sleep duration and sNfL level (β = 0.65, p = 0.0280). After adjusted for covariates, this relationship still (β = 0.82, p = 0.0052). Segmented regression showed that the turning point of sleep duration was 7 h 1 h decrease in sleep duration was significantly associated with -1.26 higher sNfL level (95 % CI: 2.25, -0.28; p = 0.0115) when sleep duration <7 h; however, 1 h increase in sleep duration was significantly associated with 3.20 higher sNfL level (95 % CI: 2.13, 4.27; p < 0.0001) when sleep duration >7 h. Furthermore, the stratified analysis indicated that the associations between sleep duration and sNfL level were stronger among those normal body mass index and trouble sleeping (p-interaction <0.0001 and 0.0003).

Conclusion

In summary, there was a J-shaped relationship between sleep duration and sNfL level in the United States of America representative group, these may suggest that extreme sleep duration can be deleterious judged by sNfL level. And still need large cohort study to determine the accurate relationship, and cluster analysis to infer the nervous disease connected with extreme sleep duration.

Insomnia and risk of mortality in older adults

Existing evidence linking insomnia to all-cause mortality in older individuals remains inconclusive. We conducted a retrospective study of a large cohort of veterans aged 65-80 years old identified from the Corporate Data Warehouse, a large data repository derived from the Veterans Health Administration integrated medical records. Veterans' enrollees with and without International Classification of Diseases, Ninth and Tenth Revision, codes corresponding to insomnia diagnosis between 1 January 2010 and 30 March 2019 were assessed for eligibility. The primary outcome was all-cause mortality. A total of 36,269 veterans, 9584 with insomnia and 26,685 without insomnia, were included in the analysis. Baseline mean (SD) age was 72.6 (4.2) years. During a mean follow-up of 6.0 (2.9) years of the propensity score matched sample, the mortality rate was 34.8 [95% confidence interval: 33.2-36.6] deaths per 1000 person-years among patients with insomnia compared with 27.8 [95% confidence interval: 26.6-29.1] among patients without insomnia. In a Cox proportional hazards model, insomnia was significantly associated with higher mortality (hazard ratio: 1.39; [95% confidence interval: 1.27-1.52]). Patients with insomnia also had a higher risk of non-fatal cardiovascular events (hazard ratio: 1.21; [95% confidence interval: 1.06-1.37]). Secondary stratified analyses by sex, race, ethnicity and hypertension showed no evidence of effect modification. A higher risk of mortality (hazard ratio: 1.51; [95% confidence interval: 1.33-1.71]) was observed when depression was present compared with absent (hazard ratio: 1.26; [95% confidence interval: 1.12-1.44]; p = 0.02). In this cohort study, insomnia was associated with increased risk-adjusted mortality and non-fatal cardiovascular events in older individuals.

Edward O. Bixler, PhD: from the Apollo project and chimpanzees to sleep epidemiology

What an honor to write about Dr. Edward O. Bixler's contributions to the sleep field. In 1967, Dr. Bixler published a case report on a chimpanzee with implanted brain electrodes while working at an Air Force base in New Mexico. A few years later, in 1971, he published on the sleep effects of flurazepam in individuals with insomnia together with Dr. Anthony Kales, data that he had collected when the Sleep Research & Treatment Center (SRTC) was housed at the University of California Los Angeles. Dr. Bixler, a meticulous scientist, learned from Dr. Kales, a devoted clinician, to study "the whole patient, and all aspects of sleep," a legacy that continued when the SRTC moved to Penn State in Hershey. Indeed, Dr. Bixler's tenure at Penn State from 1971 until 2019 kept the science of the SRTC focused on that premise and helped translate scientific evidence into clinical care. He not only contributed early to the pharmacology of sleep and the effects of hypnotics, but he was also a pioneer in "sleep epidemiology." His "Prevalence of sleep disorders in the Los Angeles metropolitan area" study of 1979 was the first rigorous epidemiological study on sleep disturbances. Starting in 1990, he established the Penn State Adult Cohort to estimate the prevalence and natural history of sleep-disordered breathing and other sleep disorders in adults. Inspired by life-course epidemiology, he established in 2001 the Penn State Child Cohort to estimate the same phenomena in children. This Living Legend paper captures and highlights Dr. Bixler's enduring legacy to sleep science.

Sleep duration and quality are associated with health-related quality of life in adults aged 60 years and older

BACKGROUND

The current study aimed to determine the association between sleep duration and quality with health-related quality of life (HRQoL) among the Iranian older persons.

METHODS

This study was conducted on a representative sample of 3452 Iranian older people (≥ 60 years) who participated in the Iranian Longitudinal Study on Ageing (IRLSA) launched in Neyshabur (Razavi Khorasan province, northeastern Iran). The Persian versions of 12-Item Short Form Survey (SF-12) and Pittsburgh Sleep Quality Index (PSQI) were utilized to measure the level of HRQoL and the level of sleep duration and quality, respectively. Multiple linear regression model was performed to analyze the data and clarify the independent association of sleep duration and quality with HRQoL.

RESULTS

More than half of the study population (52.4%) suffered from poor sleep quality. 57.3% and 3.9% of individuals were short sleepers (< 7 h) and long sleepers (equal or more than 9 h), respectively. The total score of HRQoL was achieved 65.87 ± 20.55. After adjusting the covariates, the results indicated that short sleep duration was negatively associated with HRQoL (P < 0.05), whereas no significant associations were found between long sleep duration and HRQoL (P > 0.05). Interestingly, the results of multiple linear regression model revealed a significant negative association between poor sleep quality and HRQoL (P < 0.001).

CONCLUSION

The current study confirmed that short sleep duration and poor sleep quality were independently associated with lower HRQoL in the older persons. Therefore, interventional courses should be planned to enrich sleep-related healthcare and general HRQoL in the older persons.

Sleep duration, insomnia and cognitive performance in the Elsa-Brasil cohort: a cross-sectional analysis

OBJECTIVE

To investigate the single and combined associations between sleep disturbances (sleep duration, insomnia symptoms in the last 30 nights, and daytime tiredness) and performance in cognitive tests.

METHODS

Cross-sectional analysis of data from visit 2 (2012-2014) of the Longitudinal Study of Adult Health from a cohort of active and retired civil servants from six Brazilian capitals. Polynomial regression with quadratic term and multiple linear regression models were performed to assess single and combined associations between sleep disturbances and memory performance, fluency, executive functions, and global cognition.

RESULTS

A total of 7,248 participants were included, with a mean age of 62.7 years (standard deviation [SD]=5.9), and 55.2% were women. Inverted U-shaped associations were observed between sleep duration and performance on all cognitive abilities, suggesting that durations shorter or longer than seven hours are associated with worse performance, regardless of age. Reported insomnia was associated with worse executive function (β: -0.08; 95% confidence interval [CI]: -0.15 to -0.01), and the magnitudes of associations were higher for individuals with insomnia at two or more moments (β: -0.12; 95%CI -0.19 to -0.05) or, especially, insomnia combined with short sleep (β: -0.18; 95%CI -0.24 to -0.11). Insomnia in two or more periods was also associated with lower memory and global cognition. There was no association between any sleep disturbance tested and verbal fluency. Isolated daytime tiredness was not associated with performance in the evaluated tests.

CONCLUSION

The results suggest that extreme sleep durations are detrimental to almost all cognitive abilities investigated, whereas insomnia appears to affect more severely the executive function.

Self-Reported Sleep Duration and Bedtime Are Associated with Dementia Risk in Community-Dwelling People Aged 40-74 Years: The Murakami Cohort Study

Background

Sleep is a potentially modifiable factor associated with dementia, including Alzheimer's disease, but current evidence supporting this is insufficient.

Objective

This study aimed to determine whether sleep duration and bedtime patterns are associated with the risk of dementia among middle-aged and older people.

Methods

This cohort study had an eight-year follow-up period. Participants were 13,601 community-dwelling people aged 40-74 years living in Murakami (Niigata, Japan). Data were collected using a self-administered questionnaire. Predictors were self-reported sleep duration and bedtime, and the outcome was newly-diagnosed dementia determined using the long-term care insurance database. Covariates were demographic characteristics, body mass index, smoking, alcohol consumption, total physical activity, insomnia symptoms, disease history, and either bedtime or sleep duration. Cox proportional hazard models were used to calculate hazard ratios (HRs).

Results

The mean age of participants at baseline was 59.2 years. Over a mean follow-up period of 8.0 years, 319 cases of dementia were observed. A long self-reported sleep duration relative to the reference sleep duration (7 hours) was associated with increased dementia risk, with the "8 hours" group (adjusted HR = 1.30, 95% CI:0.99-1.73) and "≥9 hours" group (adjusted HR = 1.46, 95% CI:1.00-2.15) having an increased risk (marginally significant) relative to the reference group. Early bedtime was associated with increased dementia risk (adjusted p for trend = 0.0010), with the "21 : 00 or earlier" group (adjusted HR = 1.61, 95% CI:1.14-2.28) having an increased risk relative to the reference ("23 : 00").

Conclusions

A long self-reported sleep duration and early bedtime are both associated with increased dementia risk in middle-aged and older people.

Insomnia nosology: a systematic review and critical appraisal of historical diagnostic categories and current phenotypes

Insomnia nosology has significantly evolved since the Diagnostic and Statistical Manual (DSM)-III-R first distinguished between 'primary' and 'secondary' insomnia. Prior International Classification of Sleep Disorders (ICSD) nosology 'split' diagnostic phenotypes to address insomnia's heterogeneity and the DSM nosology 'lumped' them into primary insomnia, while both systems assumed causality for insomnia secondary to health conditions. In this systematic review, we discuss the historical phenotypes in prior insomnia nosology, present findings for currently proposed insomnia phenotypes based on more robust approaches, and critically appraise the most relevant ones. Electronic databases PsychINFO, PubMED, Web of Science, and references of eligible articles, were accessed to find diagnostic manuals, literature on insomnia phenotypes, including systematic reviews or meta-analysis, and assessments of the reliability or validity of insomnia diagnoses, identifying 184 articles. The data show that previous insomnia diagnoses lacked reliability and validity, leading current DSM-5-TR and ICSD-3 nosology to 'lump' phenotypes into a single diagnosis comorbid with health conditions. However, at least two new, robust insomnia phenotyping approaches were identified. One approach is multidimensional-multimethod and provides evidence for self-reported insomnia with objective short versus normal sleep duration linked to clinically relevant outcomes, while the other is multidimensional and provides evidence for two to five clusters (phenotypes) based on self-reported trait, state, and/or life-history data. Some approaches still need replication to better support whether their findings identify true phenotypes or simply different patterns of symptomatology. Regardless, these phenotyping efforts aim at improving insomnia nosology both as a classification system and as a mechanism to guide treatment.

Mechanisms of cognitive behavioural therapy for insomnia

Although much is known now about behavioural, cognitive and physiological consequences of insomnia, little is known about changes after cognitive behavioural therapy for insomnia on these particular factors. We here report baseline findings on each of these factors in insomnia, after which we address findings on their changes after cognitive behavioural therapy. Sleep restriction remains the strongest determinant of insomnia treatment success. Cognitive interventions addressing dysfunctional beliefs and attitudes about sleep, sleep-related selective attention, worry and rumination further drive effectiveness of cognitive behavioural therapy for insomnia. Future studies should focus on physiological changes after cognitive behavioural therapy for insomnia, such as changes in hyperarousal and brain activity, as literature on these changes is sparse. We introduce a detailed clinical research agenda on how to address this topic.

Effect of Kami Guibi-tang (KGT) in elderly subjects with insomnia: a study protocol from a single center, randomized, double-blind, placebo-controlled trial

BACKGROUND

The incidence of insomnia increases with age and is related to cognitive function in older adults; therefore, it is important to manage it actively. In this study, we report a protocol for the evaluation of the efficacy and safety of Kami Guibi-tang (KGT), a herbal prescription that has been widely used in East Asia for insomnia, forgetfulness, and depression, in older adults with insomnia.

METHODS

In this single-center, double-blind, randomized controlled trial, 60 older adults with insomnia and subjective cognitive decline will be recruited and randomly assigned to the KGT or placebo group. The KGT group will take KGT granules thrice a day for 12 weeks, whereas the control group will take placebo granules in the same manner. Participants will be assessed for sleep, cognitive function, quality of life, and depression using the Pittsburgh Sleep Quality Index-Korean (PSQI-K), Insomnia Severity Index-Korean (ISI-K), Seoul Neuropsychological Screening Battery-Dement (SNSB-D), 36-item MOS Short Form Survey (SF-36) and Short version of the Geriatric Depression Scale (S-GDS) before and at the end of administration of the investigational product. The PSQI-K, ISI-K, and SF-36 will be further assessed 12 weeks after the end of medication to determine whether the effects on sleep and quality of life are sustained. The PSQI-K total score difference between the two groups at 12 and 24 weeks will be the primary outcome; all other endpoints will be secondary. Safety will be assessed by performing blood tests and electrocardiograms before taking the investigational drug, 6 weeks after taking the drug, and 12 weeks after taking the drug; any adverse events will be observed throughout the study.

DISCUSSION

The protocol will provide a detailed process for a clinical trial to evaluate the efficacy and safety of KGT in elderly patients with insomnia. We will also investigate if changes in cognitive function correlated with improvements in insomnia.

TRIAL REGISTRATION

This trial was registered at CRIS (Clinical Research Information Service) on April 27, 2023 (KCT0008391, version 2.0).  https://cris.nih.go.kr/cris/search/detailSearch.do?seq=24811&search_page=L .

The relationship between the intake of branched-chain and aromatic amino acids and individuals' sleep quality based on body mass index, gender, and age

Sleep disorder is a relatively common problem that causes chronic conditions such as obesity, diabetes, and cardiovascular diseases. It is believed that diet regulates sleep. So, investigating the relationship between branched-chain amino acids (BCAAs) and aromatic amino acids intake with sleep quality based on age, gender and Body Mass Index (BMI) is important. A total of 172 males and females aged 18-65 participated in this study. The questionnaires were given online to them, included demographic information, food frequency questionnaire (FFQ), International Physical Activity Questionnaire, and Pittsburgh Sleep Quality Index. The Chalder fatigue scale (CFQ) was also used to measure the extent and severity of fatigue. The intake of amino acids was investigated by FFQ. The relationship between amino acids intake and sleep quality was investigated using Pearson's test. The results showed that intake of energy, macronutrients, and some micronutrients had a significant relationship with the quality of sleep of men compared to that of women (P < 0.05). No difference in sleep duration was observed between the two genders. There was a significant, positive association between sleep duration and the intake of BCAA (CC = 0.205, P = 0.031) and aromatic amino acids (CC = 0.22, P = 0.02) in the participants with normal BMI. Significant differences were seen in the intake of BCAA according to BMI which these differences were between lean and obese people, lean and overweight people, obese and normal, and overweight people. It demonstrated that in individuals with normal BMI, amino acids, protein, and carbohydrate intake may affect sleep duration and with modification of these factors sleep quality may get better. More study is needed to confirm these findings.

Oral Microbiome, Mental Health, and Sleep Outcomes During the COVID-19 Pandemic: An Observational Study in Chinese and Korean American Immigrants

COVID-19 is a systemic disease whose effects are not limited to the respiratory system. The oral microbiome (OM)-brain axis is of growing interest in understanding the broader, neuropsychiatric, impacts of the COVID-19 pandemic through a systems biology lens. In this context, mental health and sleep disturbance are often reported by Asian Americans. In a cross-sectional observational study design, we examined the associations of the oral microbiome with mental health among Asian Americans during the COVID-19 pandemic (between November 2020 and April 2021). Participants (n = 20) were adult Chinese and Korean American immigrants in Atlanta, Georgia, and primarily born outside the United States (60%) with a mean age of 34.8 years ±14 (standard deviation). Participants reported depressive symptoms, anxiety, and sleep disturbance, as measured by standard questionnaires. The OM was characterized by 16S rRNA V3-V4 gene using saliva. Depressive symptoms and anxiety were reported by 60% (n = 12) of participants, whereas 35% (n = 7) reported sleep disturbance. The α-diversity was significantly associated with depressive symptoms, and marginally with anxiety. Participants with depressive symptoms and anxiety had enriched Rothia and Scardovia, respectively, whereas those without symptoms had enriched Fusobacterium. Individuals with sleep disturbance had enriched Kingella. In conclusion, this study suggests significant associations of the OM diversity with certain mental health dimensions such as depressive symptoms and anxiety. Specific taxa were associated with these symptoms. The present observations in a modest sample size suggest the possible relevance of the OM-brain axis in studies of mental health during COVID-19.

Relationships among insomnia, executive function, and suicidal ideation in depressed outpatients: A mediation analysis

Insomnia is a risk factor for suicide, and both are associated with cognitive problems. However, prior research has not examined insomnia, cognition, and suicidal ideation within one sample. We describe cross-sectional associations among insomnia, psychomotor speed, set shifting, and suicidal ideation in 85 depressed adults. Greater insomnia was associated with slower psychomotor speed, while slower psychomotor speed was associated with a greater level (i.e., elaboration of suicide planning) and intensity of suicidal ideation in the past week. Slower set shifting was associated with a greater level and intensity of suicidal ideation in the past week. Mediation analysis indicated that psychomotor speed and set shifting both had a significant total effect on the intensity of suicidal ideation in the past week; set shifting also had a significant total effect on the sum of intensity and suicidal ideation level in the past week. The level of insomnia explained only small percentages of the total effect of either psychomotor speed or set shifting on the intensity of suicidal ideation and the sum of intensity and suicidal ideation level. The findings in this sample demonstrate significant associations of slower psychomotor speed and set shifting with suicidal ideation, with negligible contribution from insomnia.

Insomnia with objective short sleep duration in community-living older persons: A multifactorial geriatric health condition

BACKGROUND

Insomnia or poor sleep quality with objective short sleep duration (hereafter referred to as ISSD) has been identified as a high-risk phenotype among middle-aged persons. We evaluated the prevalence and clinical correlates of ISSD among community-living older persons.

METHODS

In 3053 men from the Osteoporotic Fractures in Men Sleep Study (MrOS; average age 76.4 ± 5.5 years) and 3044 women from the Study of Osteoporotic Fractures (SOF; average age 83.6 ± 3.8 years), we evaluated the prevalence of ISSD (trouble getting to sleep within 30 minutes, waking up in the middle of the night or early morning, and/or taking a medication to help with sleep ≥3 times per week and actigraphy-estimated sleep duration <6 h). Using separate logistic regression models in men and women, we evaluated the cross-sectional associations between predisposing, precipitating, and perpetuating factors for ISSD, as compared with normal sleep (no insomnia and actigraphy-estimated sleep duration of 6-9 h).

RESULTS

Overall, 20.6% of older men and 12.8% of older women had insomnia with short sleep duration. Multiple predisposing, precipitating, and perpetuating factors were cross-sectionally associated with ISSD in both men and women. In multivariable models that adjusted for predisposing factors (demographics, multimorbidity, obesity), precipitating (depression, anxiety, central nervous system-active medication use, restless legs syndrome) and perpetuating (napping, falls) factors were significantly associated with ISSD in men and women (adjusted odds ratios ranging 1.63-4.57).

CONCLUSIONS

In this cross-sectional study of community-living older men and women, ISSD was common and associated with multiple predisposing, precipitating, and perpetuating factors, akin to a multifactorial geriatric health condition. Future work should examine causal pathways and determine whether the identified correlates represent modifiable risk factors.

Insomnia disorder with objective short sleep duration (ISS) phenotype and cognitive performance: a systematic review and meta-analysis

OBJECTIVE

Insomnia disorder with objective short sleep duration (ISS) has been considered as a biologically severe subtype. The aim of this meta-analysis was to reveal the association of the ISS phenotype and cognitive performance.

METHODS

We searched PubMed, EMBASE, and the Cochrane Library for studies that observed an association of cognitive performance and insomnia with objective short sleep duration (ISS) phenotype. The "metafor" and "MAd" packages in R software (version 4.2.0) were used to calculate the unbiased standardized mean difference (Hedge's g), which was adjusted so that a negative value indicated worse cognitive performance.

RESULTS

The pooled analysis with 1339 participants revealed that the ISS phenotype was associated with overall cognitive impairments (Hedges' g = - 0.56 [- 0.89, - 0.23]), as well as specific cognitive domains including attention (Hedges' g = - 0.86 [- 1.25, - 0.47]), memory (Hedges' g = - 0.47 [- 0.82, - 0.12]), and executive function (Hedges' g = - 0.39 [- 0.76, - 0.02]). However, cognitive performance was not significantly different between insomnia disorder with objective normal sleep duration (INS) and good sleepers (p > .05).

CONCLUSION

Insomnia disorder with the ISS phenotype, but not the INS phenotype, was associated with cognitive impairments, suggesting the possible utility of treating the ISS phenotype to improve cognitive performance.

Comparison of the treatment effectiveness between lemborexant and zolpidem tartrate extended-release for insomnia disorder subtypes defined based on polysomnographic findings

STUDY OBJECTIVES

Patients with chronic insomnia may respond differently to therapeutic modalities. This study examined differences in response of individuals with 2 insomnia phenotypes-short sleep duration (I-SSD; < 6 hours) and normal sleep duration (I-NSD; ≥ 6 hours) determined by polysomnography-to treatment with lemborexant and zolpidem tartrate extended-release 6.25 mg (zolpidem ER), compared with placebo.

METHODS

Study E2006-G000-304 (Study 304; SUNRISE-1; NCT02783729) was a global, randomized, double-blind, placebo, and active comparator-controlled, parallel-group study comparing lemborexant 5 and 10 mg in individuals aged ≥ 55 years with insomnia disorder. In this analysis, changes in subjective (self-reported) variables based on sleep diaries and objective variables based on polysomnographs were assessed after 1-month administration of study drugs. Data from participants with I-SSD and I-NSD were compared.

RESULTS

In the I-SSD subgroup, both lemborexant doses provided significant benefit for sleep-onset latency (SOL), total sleep time (TST), and wake after sleep onset (WASO) vs placebo; zolpidem ER also provided significant benefit for TST and WASO, but not SOL, on both measures vs placebo. In the I-NSD subgroup, lemborexant and zolpidem ER provided significant benefit for TST and WASO vs placebo objectively but not subjectively; both doses of lemborexant provided significant benefit for SOL vs placebo subjectively, but not objectively.

CONCLUSIONS

Both drugs, but lemborexant more consistently, showed subjective and objective benefits compared with placebo in participants with insomnia with objective short sleep duration. However, neither lemborexant nor zolpidem provided consistent benefits for participants with normal sleep duration on sleep-onset and sleep maintenance variables.

CLINICAL TRIAL REGISTRATION

Registry: ClinicalTrials.gov; Name: Study of the Efficacy and Safety of Lemborexant in Subjects 55 Years and Older With Insomnia Disorder (SUNRISE 1); URL: https://clinicaltrials.gov/ct2/show/record/NCT02783729; Identifier: NCT02783729.

CITATION

Inoue Y, Nishida M, Kubota N, et al. Comparison of the treatment effectiveness between lemborexant and zolpidem tartrate extended-release for insomnia disorder subtypes defined based on polysomnographic findings. J Clin Sleep Med. 2023;19(3):519-528.

Sex differences in the effects of sleep disorders on cognitive dysfunction

Sleep is an essential physiological function that sustains human life. Sleep disorders involve problems with the quality, duration, and abnormal behaviour of sleep. Insomnia is the most common sleep disorder, followed by sleep-disordered breathing (SDB). Sleep disorders often occur along with medical conditions or other mental health conditions. Of particular interest to researchers is the role of sleep disorders in cognitive dysfunction. Sleep disorder is a risk factor for cognitive dysfunction, yet the exact pathogenesis is still far from agreement. Little is known about how sex differences influence the changes in cognitive functions caused by sleep disorders. This narrative review examines how sleep disorders might affect cognitive impairment, and then explores the sex-specific consequences of sleep disorders as a risk factor for dementia and the potential underlying mechanisms. Some insights on the direction of further research are also presented.

Variability in objective sleep is associated with Alzheimer's pathology and cognition

Both sleep duration and sleep efficiency have been associated with risk of Alzheimer's disease, suggesting that interventions to promote optimal sleep may be a way to reduce Alzheimer's disease risk. However, studies often focus on average sleep measures, usually from self-report questionnaires, ignoring the role of intra-individual variability in sleep across nights quantified from objective sleep measures. The current cross-sectional study sought to investigate the role of intra-individual variability in accelerometer-based objective sleep duration and sleep efficiency in relation to in vivo Alzheimer's disease pathology (β-amyloid and tau) using positron emission tomography imaging and cognition (working memory, inhibitory control, verbal memory, visual memory and global cognition). To examine these relationships, we evaluated 52 older adults (age = 66.4 ± 6.89, 67% female, 27% apolipoprotein E4 carriers) with objective early mild cognitive impairment. Modifying effects of apolipoprotein E4 status were also explored. Less intra-individual variability in sleep duration was associated with lower β-amyloid burden, higher global cognition and better inhibitory control, with a trend for lower tau burden. Less intra-individual variability in sleep efficiency was associated with lower β-amyloid burden, higher global cognition and better inhibitory control, but not with tau burden. Longer sleep duration was associated with better visual memory and inhibitory control. Apolipoprotein E4 status significantly modified the association between intra-individual variability in sleep efficiency and β-amyloid burden, such that less sleep efficiency variability was associated with lower β-amyloid burden in apolipoprotein E4 carriers only. There was a significant interaction between sleep duration and apolipoprotein E4 status, suggesting that longer sleep duration is more strongly associated with lower β-amyloid burden in apolipoprotein E4 carriers relative to non-carriers. These results provide evidence that lower intra-individual variability in both sleep duration and sleep efficiency and longer mean sleep duration are associated with lower levels of β-amyloid pathology and better cognition. The relationships between sleep duration and intra-individual variability in sleep efficiency with β-amyloid burden differ by apolipoprotein E4 status, indicating that longer sleep duration and more consistent sleep efficiency may be protective against β-amyloid burden in apolipoprotein E4 carriers. Longitudinal and causal studies are needed to better understand these relationships. Future work should investigate factors contributing to intra-individual variability in sleep duration and sleep efficiency in order to inform intervention studies.

Longitudinal Associations Between Cybervictimization and Adolescent Sleep Problems: The Role of Anxiety and Depressive Symptoms

Adolescents who have experienced cybervictimization are at risk for sleep problems. However, there is a gap in knowledge about the mechanism that would explain this link. The study used a longitudinal design to test if cybervictimization predicted adolescents' sleep problems 6 and 12 months later, and whether these patterns could be explained in part by emotional distress in response to the victimization. Participants were 1987 Chinese adolescents (56.1% males) ages 10 to 14 (M = 12.32, SD = 0.53) at baseline. Data were collected over the course of 1 year, in three waves 6 months apart. The adolescents completed questionnaires regarding cybervictimization, sleep problems, depressive symptoms, and anxiety symptoms at all three time points. Autoregressive cross-lagged models showed that cybervictimization predicted later sleep problems after controlling for traditional peer victimization, and anxiety and depressive symptoms mediated this link. Multivariate latent growth models showed that the developmental trajectories of cybervictimization, sleep problems, anxiety symptoms, and depressive symptoms were related in complex ways over time. Measures of study variables were self-reported, and generalizability may be limited by a sample of adolescents from school in China. These results are important because of their implications for prevention and treatment of adolescents' sleep problems evoked by cybervictimization.

Insomnia with objective short sleep duration is associated with hypertension

Insomnia with objective short sleep duration has been proposed as the most biologically severe phenotype of the disorder associated with cardiometabolic morbidity in population-based samples. In this study, we investigated the association between insomnia with objective short sleep duration and hypertension in a large clinical sample. We studied 348 patients diagnosed with chronic insomnia disorder based on International Classification of Sleep Disorders Third Edition criteria and 150 normal sleepers. Objective short sleep duration was defined by the median total sleep time of the sample (< 7 hr) measured with 1-night polysomnography. Hypertension was defined based on blood pressure levels, antihypertensive medication use and/or a physician diagnosis. After adjusting for potential confounders, patients with chronic insomnia disorder who slept < 7 hr were associated with 2.8-fold increased odds of hypertension compared with normal sleepers who slept ≥ 7 hr (odds ratio = 2.81, 95% confidence interval = 1.068-7.411) or < 7 hr (odds ratio = 2.75, 95% confidence interval = 1.005-7.542), whereas patients with chronic insomnia disorder who slept ≥ 7 hr (odds ratio = 1.52, 95% confidence interval = 0.537-4.285) or normal sleepers who slept < 7 hr (odds ratio = 1.07, 95% confidence interval = 0.294-3.904) were not significantly associated with increased odds of hypertension compared with normal sleepers who slept ≥ 7 hr. Linear regression analyses showed that, for every hour decrease in total sleep time, systolic and diastolic blood pressure increased by 1.014 mmHg (p = 0.045) and 0.923 mmHg (p = 0.015), respectively, in patients with chronic insomnia disorder but not in normal sleepers. Our findings further support that insomnia with objective short sleep duration is a risk factor for hypertension, and objective short sleep duration may be a useful marker of the biological severity of chronic insomnia disorder in clinical practice.

Insomnia disorder increases the risk of subjective memory decline in middle-aged and older adults: a longitudinal analysis of the Canadian Longitudinal Study on Aging

STUDY OBJECTIVES

To examine the longitudinal association between probable insomnia status and both subjective and objective memory decline in middle-aged and older adults.

METHODS

26 363 participants, ≥45 years, completed baseline and follow-up (3 years after baseline) self-reported evaluations of sleep and memory, and neuropsychological testing in the following cognitive domains: memory, executive functions, and psychomotor speed. Participants were categorized as having probable insomnia disorder (PID), insomnia symptoms only (ISO), or no insomnia symptoms (NIS), based on sleep questionnaires. Participants were further grouped based on their sleep change over time. Prospective odds of self-reported memory worsening were assessed using logistic regression, and associations between insomnia and cognitive performance were assessed via linear mixed-effects modeling, adjusted for demographic, lifestyle, and medical factors.

RESULTS

An increased odds (OR 1.70; 95% CI 1.29-2.26) of self-reported memory worsening was observed for NIS participants at baseline who developed PID at follow-up compared to those who developed ISO or remained NIS. Additionally, participants whose sleep worsened from baseline to follow-up (i.e. transitioned from NIS to ISO, ISO to PID, or NIS to PID) displayed increased odds (OR 1.22; 95% CI 1.10-1.34) of subjective memory worsening at follow-up compared to those who remained insomnia-free or improved their sleep. There were no significant associations between the development of PID or worsening sleep and performance on neuropsychological tests.

CONCLUSIONS

These findings of an increased odds for subjective memory decline in middle-aged and older adults with insomnia disorder suggest insomnia may be an important target for early interventions addressing age-related cognitive decline.

The association between subjective-objective discrepancies in sleep duration and mortality in older men

A discrepancy in subjective and objective estimations of sleep duration, which often diverge, could have long-term adverse effects on health outcomes in older adults. Using data from 2674 older adult men (≥ 65 years of age) of the Osteoporotic Fractures in Men Sleep Study, we assessed the longitudinal association between misperception index (MI), calculated as MI = (objective sleep duration - subjective sleep duration)/objective sleep duration, and all-cause mortality. During the follow-up with a mean (standard deviation) of 10.8 (4.2) years, 1596 deaths were observed. As a continuous variable, MI showed a linear relationship with all-cause mortality after adjusting for multiple covariates, including polysomnography-measured objective sleep duration [fully adjusted hazard ratio (HR), 0.69; 95% confidence interval [CI], 0.56-0.84]. As a categorical variable, the lowest MI quartile (vs. the interquartile MI range) was associated with increased mortality (fully adjusted HR, 1.28; 95% CI, 1.12-1.46), whereas the highest MI quartile was not associated with mortality (fully adjusted HR, 0.97; 95% CI, 0.85-1.11). The subjective overestimation of sleep duration may be a risk factor for all-cause mortality in older men. Future studies should examine why subjective overestimation of sleep duration is associated with all-cause mortality from a physiological perspective.

Elevated beta activity in the nighttime sleep and multiple sleep latency electroencephalograms of chronic insomnia patients

Aim

To examine the 24-h hyperarousal hypothesis of insomnia using electroencephalographic (EEG) spectral analysis of overnight polysomnography (PSG) and daytime multiple sleep latency tests (MSLTs).

Methods

Standard PSG and MSLT were recorded in 31 chronic insomniacs (CIs) (21 females, mean age 36.19) and in 21 normal controls (NCs) (18 females, mean age 34.76). EEG spectral analyses were conducted and relative power was obtained for each sleep stage during PSG and each session during MSLTs. Subsequently, CIs were subdivided based on sleep efficiency (SE < or ≥ 85%) or mean sleep latency (MSL) of MSLT (< or ≥ 15 min), and beta power was compared among NCs and CIs subgroups. General liner regression analyses of beta power and PSG parameters were conducted.

Results

CIs had significantly greater beta power in nighttime W, N1, N2, NREM, and in total overnight and in MSLT sessions compared with NCs. CIs with lower PSG-SE or longer MSLT-MSL showed higher beta power at nighttime. Compared with NCs, increased beta power was limited to CIs with lower PSG-SE or longer MSLT-MSL during MSLT sessions. In all subjects, total daytime beta was positively correlated to total overnight beta and MSL, total overnight beta was negatively related to SE. In CIs, total daytime beta and total overnight beta were positively correlated.

Conclusion

Our results support the hypothesis of 24-h cortical hyperarousal in insomnia. We conclude that 24-h cortical hyperarousal is clearly present in insomnia and is greater in insomnia with objective findings.

Insomnia

Insomnia is highly prevalent in clinical practice, occurring in up to 50% of primary care patients. Insomnia can present independently or alongside other medical conditions or mental health disorders and is a risk factor for the development and exacerbation of these other disorders if not treated. In 2016, the American College of Physicians recommended that insomnia be specifically targeted for treatment. The recommended first-line treatment for insomnia, whether the underlying cause has been identified or not, is cognitive behavioural therapy for insomnia (CBT-I). Currently, there is no global consensus regarding which pharmacological treatment has the best efficacy or risk-benefit ratio. Both CBT-I and pharmacological intervention are thought to have similar acute effects, but only CBT-I has shown durable long-term effects after treatment discontinuation. Administering a combined treatment of CBT-I and medication could decrease the latency to treatment response, but might diminish the durability of the positive treatment effects of CBT-I.

IL-1α and TNF-α as an inducer for ROS-mediated NLRP1/NLRP3 inflammasomes activation in mononuclear blood cells from individuals with chronic insomnia disorder

BACKGROUND

There are some evidence that cytokines may play an important role in sleep deprivation; however, the underlying mechanisms are still unknown. So, the present study aim to evaluate the relationship between NLRP1 and NLRP3 inflammasomes activation of blood cells and serum levels of cytokines in individuals with chronic insomnia disorder (CID).

METHODS

Blood samples were collected from 24 individuals with CID and 24 healthy volunteers. The inflammasomes activation was evaluated using real time PCR of NLRP1, NLRP3, ASC, and Caspase-1; western blot of NLRP1 and NLRP3; caspase-1 activity assay; and serum levels of IL-1β, IL-18 and other cytokines using enzyme-linked immunosorbent assay (ELISA). ROS generation in blood cells were detected by flow cytometry assay. As well, MRI scans were obtained on a Siemens Magnetom Avanto 1.5 T MRI whole body scanner using an 8-channel head coil.

RESULTS

We found the increased activity of NLRP1 and NLRP3 inflammasomes in blood cells; the increased serum levels of pro-inflammatory cytokines; and the decreased serum levels of IL-10 and TGF-β in individuals with CID. We observed significant correlation between increased serum concentration of IL-1β and the severity of insomnia in individuals with CID. The levels of ROS in blood cells was found to be correlated with IL-1α and TNF-α concentrations in serums from individuals with CID. Moreover, the included individuals with CID demonstrated the increased right-cerebellum-cortex and lateral ventricle MD bilaterally compared to controls.

CONCLUSIONS

This study provided new insights on the pathogenesis of CID and the effects of cytokines on inflammasome activation.

Human fertility and sleep disturbances: A narrative review

INTRODUCTION

Many factors may be hidden behind the global fertility decline observed in Western countries. Alongside the progressively increased age of infertile couples, environmental and behavioural factors, including non-optimal lifestyle habits, should be considered. Among these, sleep disorders have been suggested to be linked to human fertility.

METHODS

This is a narrative review, describing first sleep physiology, its disturbances, and the tools able to quantify sleep dysfunction. Then, we consider all available studies aimed at investigating the connection between sleep disorders and human fertility, providing a comprehensive view on this topic.

RESULTS

Forty-two studies investigating the relationship between sleep habits and human reproduction were included. All the published evidence was grouped according to the aspect of human fertility considered, i.e. i) female reproductive functions, ii) male reproductive functions, iii) natural conception and iv) assisted reproduction. For each of the sub-groups considered, the connection between sleep dysregulation and human fertility was classified according to specific sleep characteristics, such as sleep duration, quality, and habits. In addition, possible physio-pathological mechanisms proposed to support the link between sleep and fertility were summarized.

CONCLUSION

This review summarizes the most relevant findings about the intricate and still largely unknown network of molecular pathways involved in the regulation of circadian homeostasis, to which sleep contributes, essential for reproductive physiology. Thus, many mechanisms seem correlate sleep disorders to reproductive health, such as adrenal activation, circadian dysregulation, and genetic influences. This review highlights the need to properly designed trials on the topic.

The 103,200-arm acceleration dataset in the UK Biobank revealed a landscape of human sleep phenotypes

SignificanceHuman sleep phenotypes are diversified by genetic and environmental factors, and a quantitative classification of sleep phenotypes would lead to the advancement of biomedical mechanisms underlying human sleep diversity. To achieve that, a pipeline of data analysis, including a state-of-the-art sleep/wake classification algorithm, the uniform manifold approximation and projection (UMAP) dimension reduction method, and the density-based spatial clustering of applications with noise (DBSCAN) clustering method, was applied to the 100,000-arm acceleration dataset. This revealed 16 clusters, including seven different insomnia-like phenotypes. This kind of quantitative pipeline of sleep analysis is expected to promote data-based diagnosis of sleep disorders and psychiatric disorders that tend to be complicated by sleep disorders.

Increased physical activity improves gut microbiota composition and reduces short-chain fatty acid concentrations in older adults with insomnia

Physical activity (PA) can improve functional abilities, well-being, and independence in older adults with insomnia. Studies have shown that PA may be linked to changes in the gut microbiota composition and its metabolites' concentrations. This association among older adults with insomnia, however, is yet to be determined. We explored the relationships between physical activity (PA) levels, gut microbiota composition, and short-chain fatty acid (SCFA) levels in this population. Forty-nine community-dwelling adults with insomnia symptoms, aged 65 and older, participated in this study. Their average daily step-count and sleep continuity measures over a two-week period were calculated based on Actigraphic recordings. Each participant provided fecal samples for the microbiome and SCFA analyses, anthropometric measures, and information via questionnaires on medical history and food consumption. The gut microbiota composition and SCFA concentrations were determined by next-generation sequencing and Gas chromatography-mass spectrometry, respectively. Participants were divided into two groups (more and less active) according to their median step/day count. We compared the microbiota abundance and SCFA concentrations between groups and performed correlation analysis between gut microbiota abundances and study variables. Different microbiota taxa in each PA group and increased SCFAs in feces of less active individuals were found. Changes in step counts were positively or negatively associated with the relative abundance of 19 ASVs, 3 microorganisms at the family level, and 11 microorganisms at the genus level. Furthermore, significant associations were discovered among physical activity, gut microbiota, SCFAs, and sleep parameters. Our findings provide new insights on the relationship between PA, gut microbiota composition, and primary metabolites in older adults with insomnia.

Insomnia with objective short sleep duration in women with temporomandibular joint disorder: quantitative sensory testing, inflammation and clinical pain profiles

OBJECTIVES/BACKGROUND

Temporomandibular joint disorder (TMD) is a disabling facial pain syndrome with a high prevalence of insomnia that primarily affects women. Insomnia with objective short sleep duration (ISSD) is an emerging phenotype linked to cardiometabolic morbidity and increased mortality. The present report examines the association of ISSD on clinical and laboratory pain and systemic inflammation in TMD.

METHODS

We collected baseline data from 128 women with TMD and insomnia as part of a clinical trial evaluating psychological interventions for sleep and pain. Participants completed self-report questionnaires, one-night polysomnography, a two-week actigraphy assessment, quantitative sensory testing (QST) to assess cold pain tolerance, pain sensitivity and central sensitization and circulating Interleukin-6 levels were measured to assess systemic inflammation.

RESULTS

24.2% (n = 31) of the sample met criteria for ISSD [polysomnography (sleep duration <6 h)]. Compared to those with insomnia and normal sleep duration, ISSD were older (40.4 vs. 34.9,p < 0.05) and a greater proportion self-identified as Black (48.4% vs 11.3%,p < 0.001). Multivariate regressions revealed that ISSD endorsed higher self-report pain severity and functional limitation of the jaw. ISSD also demonstrated increased generalized pain sensitivity, enhanced central sensitization, cold pressor tolerance and higher resting interleukin-6 levels.

CONCLUSIONS

This is the first study to characterize the ISSD phenotype in a chronic pain sample and expand the scope of its negative health outcomes to chronic pain. ISSD may be an important chronic pain phenotype associated with a more severe clinical and laboratory pain profile, and future studies should focus on implications for treatment response and disease trajectory.

CLINICAL TRIAL

ClinicalTrials.gov Identifier: NCT01794624.

A Study of Factors Causing Sleep State Misperception in Patients with Depression

PURPOSE

Sleep state misperception, which is the discrepancy between subjective and objective sleep, is often observed in patients with depression. This phenomenon may delay the remission of depression. Previous studies have focused on the total sleep time (TST) misperception, with many of these studies using actigraphy. Thus, our study investigated depressed patients with the exploratory aim of clarifying factors associated with the sleep state misperception including the wake after sleep onset (WASO) misperception, with their objective sleep additionally evaluated by polysomnography (PSG).

PATIENTS AND METHODS

We conducted a cross-sectional study. Before undergoing overnight PSG monitoring, 40 patients with depression completed questionnaires that included the Beck Depression Inventory (BDI), Epworth sleepiness scale, Temperament and Character Inventory, and the Pittsburgh sleep quality index. Patients were also asked to estimate their subjective sleep duration after they woke up in the morning. Based on this data, we calculated the misperception using the following formula: subjective sleep duration minus objective sleep duration. We compared each factor between negative and positive misperception groups and the multiple regression analysis was performed for TST and WASO misperception, respectively.

RESULTS

Although sleep architectures, age, severity of depression and obstructive sleep apnea (OSA) exhibited differences in underestimating or overestimating the WASO, only sex differences were associated with underestimating or overestimating their total sleep time (TST). Moreover, BDI, the severity of OSA, sleep architectures (N1% and N2%), and benzodiazepine (BZD) use were significantly correlated with WASO misperception, whereas only OSA severity was significantly correlated with TST misperception. A subsequent multiple regression analysis demonstrated the BDI was independently correlated with the WASO misperception (β=0.341, p=0.049).

CONCLUSION

In clinical practice, interventions especially for OSA, and the reduction of depressive symptoms are an important method for improving patient sleep perception. Moreover, current results suggest that BZD prescriptions should be avoided as well.

Oestrogen receptor α gene polymorphisms, insomnia, and cognitive functions in perimenopausal and postmenopausal women in non-manual employment

INTRODUCTION

A potential way to explain the relationships between sleep disorders and cognitive disorders during menopausal transition is the identification of genetic markers related to changes in cognitive functions, as well as changes in quality of sleep during menopause. The objective was an analysis of the relationship between sleep disorders and cognitive disorders, according to the possessed oestrogen receptor α gene polymorphism (ESR1) in perimenopausal and postmenopausal women.

MATERIAL AND METHODS

The study included 300 women aged 44-66 years, employed as non-manual workers. A computerised battery of the Central Nervous System Vital Signs (CNS VS) test was used to diagnose cognitive functions. ESR1 polymorphisms were genotyped using PCR-RFLP methods. The Athens Insomnia Scale was used to diagnose sleep disorders.

RESULTS

More severe insomnia was related to worse complex memory, visual memory, and simple attention in the total group of examined women. More severe insomnia was related to worse simple attention in women with genotypes AG Xba I or TC Pvu II ESR1, in perimenopausal women with genotypes AG Xba I or TC Pvu II ESR1. During the postmenopausal period, the severity of insomnia negatively correlated with visual memory in carriers of Pvu II TT, and with reaction time in carriers of Xba I AA.

CONCLUSIONS

The results indicate an important role of oestrogen receptor α gene polymorphism in the modulation of the effect of insomnia on cognitive functions in peri- and postmenopausal women.

Nighttime Sleep Characteristics and White Matter Integrity in Young Adults

PURPOSE

Sleep is essential for life and plays a key role for optimal physiology, brain functioning, and health. Evidence suggests a relation between sleep and cerebral white matter integrity. Human studies report that sleep duration shows a U-shaped association with brain functioning. We hypothesized that participants with longer or shorter sleep time in the nighttime period show altered microstructural white matter integrity.

PARTICIPANTS AND METHODS

Seventy-three young adult participants were evaluated. Sleep-wake cycle parameters were assessed objectively using actigraphy. Diffusion tensor imaging studies were performed to assess white matter integrity using fractional anisotropy and mean, axial, and radial diffusivities. Relations between white matter microstructure indexes and sleep parameters were investigated through tract-based spatial statistics. Participants were grouped according to their nocturnal total sleep time: 27 in the Reference sleep group (6.5-8.0 h), 23 in the Short sleep group (<6.5 h) and 23 in the Long sleep group (>8.0 h).

RESULTS

Compared with the Reference sleep group, participants in the Long sleep group showed lower fractional anisotropy (p < 0.05) and higher radial diffusivity (p < 0.05) values in white matter tracts linked to sleep regulation (corona radiata, body of the corpus callosum, superior longitudinal fasciculus, and anterior thalamic radiation).

CONCLUSION

This pattern of reduced fractional anisotropy and increased radial diffusivity in the Long sleep group indicates an association between sleep duration and lower integrity of myelin sheaths. Because myelin is continuously remodeled in the brain, nighttime sleep characteristics appear to be a key player for its quality and maintenance.

Hypothalamic-pituitary-adrenal (HPA) axis response to exogenous corticotropin-releasing hormone (CRH) is attenuated in men with chronic insomnia

Although insomnia is by far the most common sleep disorder, our understanding of its neurobiology is limited. Insomnia, particularly when associated with objective sleep disturbance, has been associated with activation of the hypothalamic-pituitary-adrenal axis. The objective of this experimental study was to compare the response of the hypothalamic-pituitary-adrenal axis to ovine corticotropin-releasing hormone, a stress test, in men with insomnia versus controls. Circulating adrenocorticotropic hormone and cortisol levels were assayed before (-30 min, -15 min), at (0 min) and after (+5 min, +15 min, +30 min, +60 min, +90 min, +120 min) exogenous ovine corticotropin-releasing hormone administration in 23 men (11 insomnia, 12 controls), who underwent four consecutive nights of in-lab polysomnography. Men with insomnia compared with controls demonstrated markedly and significantly shorter total sleep time (368.4 ± 8.99 min versus 411.61 ± 8.61 min; p < 0.01) and lower sleep efficiency (76.77 ± 1.80% versus 86.04 ± 1.72%; p < 0.01) on polysomnography, and showed decreased adrenocorticotropic hormone and cortisol levels after ovine corticotropin-releasing hormone administration. Adrenocorticotropic hormone levels at 15 min and 30 min were significantly lower in men with insomnia than in controls (p < 0.05). Similarly, the peak levels of cortisol at +60 min, and the total and net area under the curve levels of this hormone were significantly lower in men with insomnia than controls (all p < 0.01). Adrenocorticotropic hormone and cortisol response to ovine corticotropin-releasing hormone administration was attenuated in men with insomnia associated with objective sleep disturbance, suggesting that objectively defined insomnia subtypes have a disrupted hypothalamic-pituitary-adrenal axis function and highlight the need to develop treatments targeting the underlying hypothalamic-pituitary-adrenal axis dysregulation.

Impact of daytime sleepiness and insomnia on simple and complex cognitive task performances

OBJECTIVE

To examine the individual and combined effects of daytime sleepiness and insomnia disorder (ID) on measures of cognitive functioning.

DESIGN AND SETTING

This study was conducted at a medical center using a cross-sectional research design.

PARTICIPANTS

35 persons with ID (Mage = 40.6 years; 25 women) and 54 normal sleepers (NS; Mage = 31.5 years; 38 women).

METHODS AND MEASURES

Participants underwent two nights of home-based polysomnography (PSG) followed by daytime testing with a four-trial Multiple Sleep Latency Test (MSLT). Before each MSLT nap, they completed a computer-administered battery of reaction time tasks. Measures of response latencies and response accuracy were tabulated and used as dependent measures. The ID and NS groups were each subdivided into "alert" (eg, MSLT mean latency > 8 min) and "sleepy" (eg, MSLT mean latency ≤ 8 min) subgroups to identify hyperaroused persons with ID and allow for their comparisons with the other participant subgroups.

RESULTS

Multivariate analyses of variance showed a significant main effect for level of daytime sleepiness (F [1, 84] = 8.52, p = 0.0045) on simpler performance tasks and a significant main effect for presence vs. absence of ID (F [1,84] = 6.62, p = 0.012) on complex tasks. A lack of significant participant type x MSLT alertness level interactions in study analyses suggested those ID participants with presumed hyperaousal were not relatively more impaired than the other participant subgroups.

CONCLUSIONS

Daytime performance deficits on simple tasks seem most dependent on individuals' levels of daytime sleepiness, whereas performance deficits on more complex tasks appears related to the presence of ID. Therefore, it seems best to use complex performance measures both to document cognitive deficits among those with ID and to determine if insomnia treatments reduce such impairments.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02290405.

Association Between Sleep Quality and Pain Intensity in Mild Patients with COPD: A Community Study

Purpose

Poor sleep quality and pain were common and had been proved as an important influenced factor of quality of life for patients with COPD. The association of sleep quality with pain has been observed in other population but remains unclear in mild patients with COPD from a community setting.

Methods

A cross-sectional study was conducted to include eligible mild patients with COPD in Pudong New District of Shanghai. A structured questionnaire was used to collect general and clinical information for the patients. The Chinese version of Pittsburgh Sleep Quality Index (PSQI) and the short form of McGill Pain Questionnaire (SF-MPQ) was used to assess sleep quality and intensity of pain. Logistic regression was performed to test the association between sleeping quality and pain intensity.

Results

Two hundred and sixty-four patients with COPD, with an average age of 64 years (SD 5.78 years), were enrolled, and of 52% were women. Seventy-one (26.9%) participants reported at least one exacerbation during the past year. About 28.2% of the patients were classified as having poor sleep quality. Sleep quality was significantly associated with PRI score (adjusted odds ratio (ORad)=2.16, 95% CI: 1.16–4.00) and PPI rank (ORad=1.90, 95% CI: 1.08–3.34). People with daytime disturbance were more likely to have pain (ORad =2.03, 95% CI: 1.18–3.50).

Conclusion

Poor sleep quality was common in mild patients with COPD in community and was associated with higher pain intensity. Pain may involve an impairment of sleep quality.

Sleep Mediates Age-Related Executive Function for Older Adults with Limited Cognitive Reserve

OBJECTIVE

Sleep quantity and quality are associated with executive function (EF) in experimental studies, and in individuals with sleep disorders. With advancing age, sleep quantity and quality decline, as does the ability to perform EF tasks, suggesting that sleep disruption may contribute to age-related EF declines. This cross-sectional cohort study tested the hypothesis that poorer sleep quality (i.e., the frequency and duration of awakenings) and/or quantity may partly account for age-related EF deficits.

METHOD

Community-dwelling older adults (N = 184) completed actigraphic sleep monitoring then a range of EF tasks. Two EF factors were extracted using exploratory structural equation modeling. Sleep variables did not mediate the relationship between age and EF factors. Post hoc moderated mediation analyses were conducted to test whether cognitive reserve compensates for sleep-related EF deficits, using years of education as a proxy measure of cognitive reserve.

RESULTS

We found a significant interaction between cognitive reserve and the number and frequency of awakenings, explaining a small (approximately 3%), but significant amount of variance in EF. Specifically, in individuals with fewer than 11 years of education, greater sleep disturbance was associated with poorer EF, but sleep did not impact EF in those with more education. There was no association between age and sleep quantity.

CONCLUSIONS

This study highlights the role of cognitive reserve in the sleep-EF relationship, suggesting individuals with greater cognitive reserve may be able to counter the impact of disturbed sleep on EF. Therefore, improving sleep may confer some protection against EF deficits in vulnerable older adults.

Depressive and stress symptoms in insomnia patients predict group cognitive-behavioral therapy for insomnia long-term effectiveness: A data-driven analysis

BACKGROUND

Insomnia Disorder is characterized by high degree of phenotypic heterogeneity, that might influence treatment response.

METHODS

123 of 294 insomnia patients initially recruited (66.7% females, age=40.59±11.89) were assessed before and after group Cognitive-Behavioral Therapy for Insomnia (CBT-I), as well as at follow-up (7.8±1.6 years after the end-of-treatment). By use of latent class analysis (LCA) we identified insomnia subtypes according with baseline scores of insomnia severity and features, anxiety, depression, stress and sleepiness symptoms, circadian rhythm, and treatment effectiveness (Delta score of Insomnia Severity Index-ISI between baseline and end-of-treatment).

RESULTS

By LCA we revealed three classes: "PURE INSOMNIA", "INSOMNIA+ANXIETY+DEPRESSION+STRESS", and "INSOMNIA+ANXIETY". The improvements in insomnia severity was maintained up to 10 years after the end-of-treatment, but with differences between classes (p<0.05). Class "INSOMNIA+ANXIETY+DEPRESSION+STRESS" showed at the end-of-treatment the largest percentage of responders (63.5% = Insomnia Severity Index decrease ≥8). However, at follow up the effect was less and 48.1% had a moderate or severe insomnia (Insomnia Severity Index >14).

LIMITATIONS

The lack of a control group and the absence of a complete clinical assessment at the follow-up limit the interpretability of our results.

CONCLUSIONS

Our data driven analysis suggest insomnia heterogeneity can be categorized into sub-classes by depression, anxiety, and stress symptoms. In addition, insomnia patients with stress and depression symptoms maintained highest percentage of clinical depression at the end-of-treatment and insomnia at follow-up, in comparison with others classes. Stress and depression symptoms should be considered risk factors that play an important role in the long-term outcome of CBT-I.

Sleep misestimation among older adults suffering from insomnia with short and normal objective sleep duration and the effects of cognitive behavior therapy

STUDY OBJECTIVES

Compare the degree of sleep misestimation in older adults with insomnia presenting with objectively short relative to normal sleep duration, and investigate the differential therapeutic response on sleep misestimation between the proposed sleep duration phenotypes to cognitive-behavior therapy for insomnia (CBTi).

METHODS

Ninety-one adults (male = 43, mean age = 63.34, SD = 6.41) with sleep maintenance insomnia were classified as short sleepers (SS; <6 h total sleep time [TST]) or normal sleepers (NS; ≥6 h TST) based on one night of home-based polysomnography. Participants were randomly allocated to CBTi (N = 30 SS, N = 33 NS) or to a wait-list control condition (N = 9 SS, N = 19 NS). Sleep misestimation was calculated as the difference scores of subjective (sleep diary reported) and objective (derived from actigraphy) sleep onset latency (SOL), wake after sleep onset (WASO), and TST at pre- and post-treatment, and 3-month follow-up.

RESULTS

Prior to treatment, perception of SOL, WASO, and TST did not differ between patients with objectively short sleep duration relative to those with objectively normal sleep duration. Patients' perception of WASO and TST, improved immediately following treatment and at 3-month follow-up relative to the waitlist group. These improvements did not differ significantly between those with short or normal objective sleep duration prior to treatment.

CONCLUSIONS

The degree of sleep misestimation is similar for older adults suffering from chronic insomnia with short or normal objective sleep duration. Irrespective of objective sleep duration prior to treatment, CBTi produces significant improvements in sleep perception.

CLINICAL TRIAL REGISTRATION NUMBER

ACTRN12620000883910.

Association of sleep duration with mental health: results from a Spanish general population survey

PURPOSE

The purpose of the present study was to evaluate the association of sleep duration and mental health among the general population.

METHODS

A cross-sectional study was carried out with an adult Spanish population sample between 16 and 64 years old. The information was obtained from data provided by a randomly selected representative sample of 505 adults stratified by age, sex, and geographic area. Participants were interviewed face-to-face in their respective households with questions including sociodemographic characteristics, lifestyle, sleep duration, and the 12-item General Health Questionnaire to screen risk for poor mental health. The duration of sleep hours were grouped into the following categories: < 6 h, 6-7 h, and, > 7 h. Regression analysis was used to assess associations between sleep duration and risk of poor mental health.

RESULTS

A percentage of respondents 13.1% reported sleeping less than 6 h. The analysis demonstrated a significant (p = 0.001) negative (B = - 0.512) relationship between hours of sleep and risk of poor mental health (GHQ-12), demonstrating that reduced sleep duration increases the risk of poor mental health.

CONCLUSIONS

Sleep duration lower than 6 h is prevalent among the general population in Spain, especially among women and people who frequently use electronic devices. The results show that people who experience shorter sleep duration face a greater risk of poor mental health. These findings suggest that it is important to raise awareness of healthy sleeping habits, with emphasis on adequate sleep duration.

Chronobiology and the case for sleep health interventions in the community

Our sleep-wake cycle is determined by the interaction between our homeostatic sleep drive and circadian rhythm. Each of us has a personalised biological rhythm or chronotype that determines the optimal time to fall asleep and wake up. Chronic sleep deprivation has been linked to the development of several physical and mental health disorders, as well as accidents and occupational errors. Around the world, growing recognition of the importance of sleep has led to the adoption of practices that promote sleep health. Given that Singaporeans were consistently found to be one of the most sleep-deprived populations in the world, we believe that there is an urgent need to pursue the introduction of community-based sleep health interventions here. This includes sleep education and promotion of sleep hygiene, adopting practices to reduce social jetlag and improve sleep health, and enhancing screening and treatment of sleep disorders.

Insomnia and falls in older adults: are they linked to executive dysfunction?

BACKGROUND

Insomnia increases the incidence of falls and impairs executive function. Moreover, falls are associated with executive function impairment. The relationship between falls and executive function in patients with insomnia is not clear. The aim of this study was to evaluate relationship between falls and executive function in individuals with insomnia and a control group.

METHODS

This study involved 122 patients (47 insomnia, 75 controls). The Mini-Mental State Examination, Quick Mild Cognitive Impairment Screen, Trail Making Test A, clock-drawing test, and digit span test were used to measure executive function. Semantic and working memory dual task was also performed. Fall history was recorded and the Falls Efficacy Scale - International administered.

RESULTS

The median age of the patients was 71 years (range: 65-89 years), and 60.7% were women. The insomnia group scored lower on the three-word recall than the control group (P = 0.005), but there was no difference between the groups on cognitive tests. Fall history and fear of falling were more frequent in the insomnia group (P = 0.003, P < 0.001). Semantic and working memory dual tasks were correlated with clock-drawing test only in the insomnia group (r = -0.316, P = 0.031; r = -0.319, P = 0.029). Depression (odds ratio (OR) = 9.65, P = 0.001) and Trail Making Test A (OR = 1.025, P = 0.07) were independently associated with insomnia. Four-metre walking speed (OR = 2.342, P = 0.025), insomnia (OR = 3.453; P = 0.028), and the semantic memory dual task (OR = 1.589; P = 0.025) were also independently associated with falls.

CONCLUSION

Our study showed that dual tasking and executive function are related to falls in patients with insomnia. Managing insomnia and assessment of executive dysfunction may have beneficial effects on preventing falls.

Insomnia with objective short sleep duration is associated with cognitive impairment: a first look at cardiometabolic contributors to brain health

STUDY OBJECTIVES

Insomnia with objective short sleep duration has been previously associated with adverse cardiometabolic health outcomes as well as poorer cognitive performance in otherwise noncognitively impaired adults. However, studies demonstrating an increased prevalence of cognitive impairment (CI) in this insomnia phenotype are lacking.

METHODS

We analyzed data from Penn State Adult Cohort (N = 1,524; 48.9 ± 13.4 years; 53.4% women). Self-reported sleep difficulty was defined as normal sleep (n = 899), poor sleep (n = 453), and chronic insomnia (n = 172). Objective short sleep duration was defined as less than 6-h of sleep, based on in-lab, 8-h polysomnography. CI (n = 155) and possible vascular cognitive impairment (pVCI, n = 122) were ascertained using a comprehensive neuropsychological battery. Analyses adjusted for age, sex, race, education, body mass index, apnea/hypopnea index, smoking, alcohol, psychoactive medication, and mental and physical health problems.

RESULTS

Participants who reported poor sleep or chronic insomnia and slept objectively less than 6 hours were associated with a 2-fold increased odds of CI (OR = 2.06, 95% confidence limits [CL] = 1.15-3.66 and OR = 2.18, 95% CL = 1.07-4.47, respectively) and of pVCI (OR = 1.94, 95% CL = 1.01-3.75 and OR = 2.33, 95% CL = 1.07-5.06, respectively). Participants who reported poor sleep or chronic insomnia and slept objectively more than 6 hours were not associated with increased odds of either CI (OR = 0.72, 95% CL = 0.30-1.76 and OR = 0.75, 95% CL = 0.21-2.71, respectively) or pVCI (OR = 1.08, 95% CL = 0.42-2.74 and OR = 0.76, 95% CL = 0.16-3.57, respectively).

CONCLUSIONS

Insomnia with objective short sleep duration is associated with an increased prevalence of CI, particularly as it relates to cardiometabolic health (i.e. pVCI). These data further support that this insomnia phenotype may be a more biologically severe form of the disorder associated with cardiovascular, cerebrovascular, and neurocognitive morbidity.

Changed signals of blood adenosine and cytokines are associated with parameters of sleep and/or cognition in the patients with chronic insomnia disorder

OBJECTIVES

This study aimed to investigate whether plasma levels of adenosine, adenosine deaminase (ADA), and certain cytokines change in patients with chronic insomnia disorder (CID), and if so, whether these alterations are associated with poor sleep quality and cognitive dysfunction.

METHODS

Fifty-five CID patients were selected for the study, along with fifty-five healthy controls (HC) matched to the patients according to their basic data. All subjects completed sleep, emotion, and cognition assessments, with some CID patients also completing an overnight polysomnography. The plasma level of adenosine was measured using liquid chromatography-tandem mass spectrometry, while ADA level was quantified using a quantitative sandwich enzyme-linked immunosorbent assay. Levels of cytokines, including IL-1β, IL-2, IL-4, IL-6, IL-10, IL-12, TNF-α, and IFN-γ, were measured using Luminex liquid chip technology.

RESULTS

CID patients had a lower adenosine level, and higher levels of ADA and some of the cytokines (IL-1β, IL-2, IL-6, IL-10 and TNF-α) compared with controls. In the CID group, plasma concentrations of adenosine were negatively correlated with Pittsburgh Sleep Quality Index scores, while concentrations of IL-1β, IL-6 and TNF-α were positively correlated with these scores. Concentrations of IL-1β and TNF-α were negatively correlated with scores on the Chinese-Beijing Version of the Montreal Cognitive Assessment. Moreover, levels of IL-1β, TNF-α, IL-6, and IL-2 were positively correlated with memory test errors by CID patients after controlling for confounding factors.

CONCLUSIONS

The reduced adenosine and elevated cytokine levels of CID patients were associated with the severity of insomnia and/or cognitive dysfunction.

Premature Aging Among Trauma Survivors-The Longitudinal Implications of Sleep Disruptions on Telomere Length and Cognitive Performance

OBJECTIVES

Sleep is necessary for brain function as well as physical and cognitive processes. Sleep disruptions, common with aging, intensify among trauma survivors. Moreover, former prisoners-of-war (ex-POWs) often experience premature aging. This study investigates the longitudinal effects of sleep disruptions for ex-POWs in relation to cognitive performance and telomere length as well as between cognition and telomeres.

METHOD

This study included Israeli veterans from the 1973 Yom Kippur War who participated in four assessments (1991, 2003, 2008, 2015): (a) ex-POWs (n = 99), and (b) veterans who not were captured (controls) (n = 101). Among both groups, sleep disruptions were assessed using a self-report item in all four assessments. Cognitive performance was assessed using the Montreal Cognitive Assessment (MOCA) and telomere length was assessed via total white blood cells (leukocytes) from whole blood samples using Southern blot, both were measured only among ex-POWs in 2015. We conducted descriptive statistics, repeated measures, correlations, and path analyses.

RESULTS

Sleep disruptions were related to lower cognitive performance but not to shorter telomeres. Moreover, cognitive performance and telomere length were found to be related when sleep disruptions were taken into consideration.

CONCLUSION

Interpersonal trauma was shown to be a unique experience resulting in sleep disruptions over time, leading to cognitive impairment. These findings highlight the importance of viewing trauma survivors at high-risk for sleep disruptions. Therefore, it is imperative to inquire about sleep and diagnose cognitive disorders to help identify and treat premature aging.

Poor sleep health is associated with increased mental health problems, substance use, and HIV sexual risk behavior in a large, multistate sample of gay, bisexual and other men who have sex with men (GBMSM) in Nigeria, Africa

BACKGROUND

Poor sleep health has been linked to mental health problems, substance use, and sexual risk-taking among gay, bisexual, and other men who have sex with men (GBMSM). No known published study has examined these relationships among African GBMSM. Consequently, we investigated poor sleep health and associated health-related factors among a large multistate sample of Nigerian GBMSM.

METHODS

Between March and June 2019, 406 GBMSM were recruited from Abuja, Delta, Lagos, and Plateau and asked to complete an interviewer-administered survey. Bivariate and multivariable logistic regression models were constructed to examine the relationship between poor sleep health and other health-related factors.

RESULTS

In the past month, 45.5% of participants reported sleeping an average of 6 hours or less every night, and 30.7% reported experiencing a sleep problem. Factors associated with increased odds of reporting short sleep included: residing in Delta [adjusted odds ratio (aOR) 2.16; 95% confidence interval (CI): 1.15 to 4.04] and Lagos (aOR 2.40; 95% CI: 1.29 to 4.45), depressive symptoms (aOR 1.94; 95% CI: 1.13 to 3.32), and reporting lifetime history of using four or more drugs (aOR 2.52; 95% CI: 1.06 to 6.01). Reporting condom use at last anal sex was associated with decreased odds of reporting short sleep in the last month (aOR 0.54; 95% CI: 0.31 to 0.92). Factors associated with increased odds of reporting sleep problems included: reporting an STI diagnosis in the last year (aOR 1.79; 95% CI: 1.05 to 3.05) and reporting monthly or higher polydrug use in the last 3 months (aOR 2.19; 95% CI: 1.14 to 4.24).

DISCUSSION

Sleep health interventions should be developed for Nigerian GBMSM, which may improve mental health and reduce substance use and sexual risk-taking.

Do hypnotics increase the risk of driving accidents or near miss accidents due to hypovigilance? The effects of sex, chronic sleepiness, sleep habits and sleep pathology

Driving accidents due to hypovigilance are common but the role of hypnotics is unclear in patients suffering from sleep disorders. Our study examined factors influencing accidents and near miss accidents attributed to sleepiness at the wheel (ANMAS). Using data from an online questionnaire aimed at patients with sleep disorders, we analysed the associations between ANMAS, sociodemographic data, symptoms of sleep disorders, severity of insomnia (Insomnia Severity Index (ISI)) symptoms of anxiety and depression (Hospital Anxiety and Depression scale with depression (HADD) and anxiety (HADA) subscales), chronic sleepiness (Epworth sleepiness scale ESS), hypnotic use and information about sleep habits. Hypnotics were hierarchically grouped into Z-drugs, sedative medication, melatonin and over the counter (OTC) alternative treatments. Of 10802 participants; 9.1% reported ANMAS (Men 11.1% women 8.3%) and 24.4% took hypnotics (Z-drugs 8.5%, sedative medication 8%, melatonin 5.6% and alternative treatments 2.5%). Logistic regression analysis identified the following risk factors for ANMAS: moderate (OR 2.4; CI: 2.10-2.79) and severe sleepiness (ESS OR 5.66; CI: 4.74-6.77), depression (HADD OR 1.2; CI: 1.03-1.47), anxiety (HADA OR 1.2;CI: 1.01-1.47), and insufficient sleep (OR1.4; CI: 1.2-1.7). Hypnotics were not associated with an increased risk of ANMAS in patients suffering from insomnia. Risk factors varied according to sex: in females, sex (OR 0.; CI: 0.55-0.74), mild insomnia (OR 0.5; CI: 0.3-0.8) and use of alternative treatments (OR 0.455, CI:0.23-0.89) were protective factors and risk was increased by sleepiness, sleep debt, social jetlag, caffeine use, anxiety and depression. In men no protective factors were identified: sleepiness, sleep debt, and severe insomnia were associated with an increased risk of ANMAS. In clinical practice, all patients with daytime sleepiness and men with severe insomnia should be counselled concerning driving risk and encouraged to avoid sleep debt.

Effects of insomnia symptoms and objective short sleep duration on memory performance in youths

Sleep quantity and quality are both important for optimal development and functioning during youth. Yet few studies have examined the effects of insomnia symptoms and objective short sleep duration on memory performance among adolescents and young adults. One-hundred and ninety participants (female: 61.6%) aged from 12 to 24 years completed this study. All participants underwent a clinical interview, a 7-day actigraphic assessment, a battery of self-report questionnaires and cognitive tests to assess working memory and episodic memory. Insomnia symptoms were defined as a score ≥ 9 on the Insomnia Severity Index, and objective short sleep duration was defined as average total sleep time less than 7 hr for those aged 12-17 years, and 6 hr for those aged 18 years and above as assessed by actigraphy. Insomnia symptoms were significantly associated with worse self-perceived memory (p < .05) and poorer performance on the digit span task (p < .01), but not the dual N-back task and verbal learning task. There was no significant difference in any of the memory measures between participants with objective short sleep duration and their counterparts. No interaction effect was found between insomnia and short sleep duration on any of the objective memory outcomes. Insomnia symptoms, but not objective short sleep duration, were associated with poorer subjective memory and objective working memory performance in youths. Further studies are needed to investigate the underlying mechanisms linking insomnia and memory impairments, and to delineate the long-term impacts of insomnia on other aspects of neurocognitive functioning in youth.

Onset of regular cannabis use and young adult insomnia: an analysis of shared genetic liability

STUDY OBJECTIVES

Estimate the genetic and environmental influences on the relationship between onset of regular cannabis use and young adult insomnia.

METHODS

In a population-based twin cohort of 1882 twins (56% female, mean age = 22.99, SD = 2.97) we explored the genetic/environmental etiology of the relationship between onset of regular cannabis use and insomnia-related outcomes via multivariate twin models.

RESULTS

Controlling for sex, current depression symptoms, and prior diagnosis of an anxiety or depression disorder, adult twins who reported early onset for regular cannabis use (age 17 or younger) were more likely to have insomnia (β = 0.07, p = 0.024) and insomnia with short sleep on weekdays (β = 0.08, p = 0.003) as young adults. We found significant genetic contributions for the onset of regular cannabis use (a2 = 76%, p < 0.001), insomnia (a2 = 44%, p < 0.001), and insomnia with short sleep on weekdays (a2 = 37%, p < 0.001). We found significant genetic correlations between onset of regular use and both insomnia (rA = 0.20, p = 0.047) and insomnia with short sleep on weekdays (rA = 0.25, p = 0.008) but no significant environmental associations between these traits.

CONCLUSIONS

We found common genetic liabilities for early onset of regular cannabis use and insomnia, implying pleiotropic influences of genes on both traits.

Offline Bi-Frontal Anodal Transcranial Direct Current Stimulation Decreases Total Sleep Time Without Disturbing Overnight Memory Consolidation

OBJECTIVES

A proposed replay of memory traces between the hippocampus and frontal cortical brain areas during sleep is of high relevance for overnight memory consolidation. Recently, we demonstrated that bi-frontal anodal transcranial direct current stimulation (tDCS) prior to sleep increases waking EEG gamma power and decreases total sleep time during the night. It is unclear whether this effect on cortical excitability has an influence on overnight memory consolidation. We hypothesized that bi-frontal evening tDCS interferes with overnight memory consolidation with a polarity specific impairment following anodal tDCS.

MATERIALS AND METHODS

Nineteen healthy participants underwent a within-subject, repeated-measures protocol in the sleep laboratory with bi-frontal tDCS applied prior to sleep according to the experimental protocol (anodal, cathodal, sham stimulation). Memory tasks for declarative and procedural memory were assessed prior to tDCS and on the following morning.

RESULTS

No deterioration of overnight memory consolidation following evening offline bi-frontal tDCS could be detected.

CONCLUSION(S)

The application of tDCS can be considered safe regarding overnight memory consolidation and represents a promising treatment approach in conditions of decreased vigilance and arousal.