Insomnia and daytime neuropsychological test performance in older adults

Multidimensional sleep health and cognitive function across adulthood

STUDY OBJECTIVES

Sleep is essential for proper function of the mind and body. Studies report the effect of sleep problems on cognition but focus on only a single or limited number of sleep indicators or on clinical populations (e.g., sleep apnea), and/or provide only cross-sectional results. This study examined cross-sectional and longitudinal associations between multidimensional assessment of sleep health and cognitive function.

METHODS

3398 adults (Mage=56years) provided self-reported sleep and objective cognitive data for the Midlife in the United States study. A subsample of 2119 participants also provided sleep and cognitive data at follow-up approximately 9years later. A multidimensional, composite measure of sleep health composed of regularity, satisfaction, alertness, efficiency, and duration based on the Ru-SATED model was utilized (higher score=better sleep health) to evaluate self-reported sleep, and cognitive function was assessed using the Brief Test of Adult Cognition by Telephone.

RESULTS

Cross-sectionally, better sleep health was associated with better cognition (B=0.121, SE=0.017, p<.001). This relationship remained significant even after adjusting for sociodemographic and health covariates (B=0.039, SE=0.014, p=.006). Longitudinally, improvement in sleep health from baseline to follow-up was associated with better cognitive performance at follow-up (B=0.031, SE=0.011, p=.004); however, this relationship did not remain significant after adjusting for covariates (B=0.015, p=.139).

CONCLUSION

Findings suggest better sleep health measured across multiple domains is associated with higher cognitive function. Future studies may want to examine potential mechanisms by which better sleep health relates to better cognitive function over time, such as reduction in stress or inflammation.

The trail less traveled: Analytical approach for creating shortened versions for virtual reality-based color trails test

The Color Trails Test ("CTT") is among the most popular neuropsychological assessment tests of executive function, targeting sustained visual attention (Trails A), and divided attention (Trails B). During the pen-and-paper (P&P) test, the participant traces 25 consecutive numbered targets marked on a page, and the completion time is recorded. In many cases, multiple assessments are performed on the same individual, either under varying experimental conditions or at several timepoints. However, repeated testing often results in learning and fatigue effects, which confound test outcomes. To mitigate these effects, we set the grounds for developing shorter versions of the CTT (<25 targets), using virtual reality (VR) based CTT (VR-CTT). Our aim was to discover the minimal set of targets that is sufficient for maintaining concurrent validity with the CTT including differentiation between age groups, and the difference between Trails A and B. To this aim, healthy participants in three age groups (total N = 165; young, middle-aged, or older adults) performed both the P&P CTT, and one type of VR-CTT (immersive head-mounted-device VR, large-scale 3D VR, or tablet). A subset of 13 targets was highly correlated with overall task completion times in all age groups and platforms (r > 0.8). We tested construct validity and found that the shortened-CTT preserved differences between Trails A and B (p < 0.001), showed concurrent validity relative to the P&P scores (r > 0.5; p < 0.05), and differentiated between age groups (p < 0.05). These findings open the possibility for shortened "CTT-versions", to be used in repeated-measures experiments or longitudinal studies, with potential implications for shortening neurocognitive assessment protocols.

Shorter sleep duration and lesser sleep efficiency are associated with poorer memory functions among non-demented, middle-aged, and older rural Indians

Introduction

Sleep is known to be involved in cognitive processes, such as memory encoding and consolidation, and poor sleep is a potential risk factor for dementia. This study aims to investigate the effect of sleep quality on memory functions among middle-aged and older adults from a rural Indian population.

Methods

Participants were non-demented, rural Indians (≥45 years) from an ongoing, prospective, aging cohort study, namely Srinivaspura Aging, NeuroSenescence, and COGnition (SANSCOG) study. Cross-sectional (baseline) data on seven sleep dimensions was obtained using the Pittsburgh Sleep Quality Index (PSQI). Memory functions were assessed using immediate recall, delayed recall, name-face association, and semantic association from a culturally validated, computerized, neurocognitive test battery. Linear regression models, unadjusted and adjusted for cognitive status, age, sex, and depression were used to analyze the association between each sleep dimension and the memory tests.

Results

A total of 1195 participants, with a mean age of 57.10 years, were included. Out of the seven sleep dimensions of the PSQI, only two dimensions, namely sleep duration and sleep efficiency, were significantly associated with memory functions. In the fully adjusted model, shorter sleep duration was significantly associated with poorer performance in delayed recall, and lesser sleep efficiency was significantly associated with poorer delayed recall and semantic association performance.

Conclusions

Specific sleep characteristics appear to influence memory functions in aging Indians well before the onset of dementia. In the backdrop of the non-availability of a definitive treatment for dementia, promptly identifying and addressing these problems could be an effective, community-level strategy for preventing dementia.

Sleep disturbances and change in multiple cognitive domains among older adults: a multicenter study of five Nordic cohorts

STUDY OBJECTIVES

We examined and compared cross-sectional and longitudinal associations between self-reported sleep disturbances and various cognitive domains in five separate Nordic European longitudinal aging studies (baseline N = 5631, mean age = 77.7, mean follow-up = 4.16 years).

METHODS

Comparable sleep parameters across studies included reduced sleep duration/quality, insomnia symptoms (sleep latency, waking up at night, and early awakenings), short and long sleep duration, and daytime napping. The cognitive domains were episodic memory, verbal fluency, perceptual speed, executive functioning, and global cognition (aggregated measure). A series of mixed linear models were run separately in each study and then compared to assess the level and rate of change in cognitive functioning across each sleep disturbance parameter. Models were adjusted for age, sex, education, hypnotic usage, depressive symptoms, lifestyle factors, cardiovascular, and metabolic conditions. By using a coordinated analytic approach, comparable construct-level measurements were generated, and results from identical statistical models were qualitatively compared across studies.

RESULTS

While the pattern of statistically significant results varied across studies, subjective sleep disturbances were consistently associated with worse cognition and steeper cognitive decline. Insomnia symptoms were associated with poorer episodic memory and participants sleeping less or more than 7-8 hours had a steeper decline in perceptual speed. In addition, daytime napping (>2 hours) was cross-sectionally and longitudinally associated with all examined cognitive domains. Most observed associations were study-specific (except for daytime napping), and a majority of association estimates remained significant after adjusting for covariates.

CONCLUSION

This rigorous multicenter investigation further supports the importance of sleep disturbance, including insomnia, long and short sleep duration, and daytime napping on baseline cognitive functioning and rate of change among older adults. These sleep factors may be targeted in future lifestyle interventions to reduce cognitive decline.

A cross-sectional observational study for ethno-geographical disparities in sleep quality, brain morphometry and cognition (a SOLACE study) in Indians residing in India, and South Asians and Europeans residing in the UK - a study protocol

Introduction

As individuals age, their sleep patterns change, and sleep disturbances can increase the risk of dementia. Poor sleep quality can be a risk factor for mild cognitive impairment (MCI) and dementia. Epidemiological studies show a connection between sleep quality and cognitive changes, with brain imaging revealing grey matter volume reduction and amyloid beta accumulation in Alzheimer's disease. However, most research has focused on Europeans, with little attention to other ethnic groups.

Methods

This is a cross sectional study comparing effects across countries and ethnicities. Group 1 (n = 193) will be Indians residing in India (new participant recruitment), Group 2 will be South Asians residing in UK and group 3 will be Europeans residing in the UK. For group 2 and 3 (n = 193), data already collected by UK-based Southall and Brent REvisited (SABRE) tri-ethnic study will be used. For group 1, Pittsburgh Sleep Quality Index questionnaire (PSQI) will be used for assessment of sleep quality, Indian Council of Medical Research (Neurocognitive ToolBox) (ICMR-NCTB) for cognition testing and a 3 T MRI cerebral scan for brain morphometry. The data will be compared to sleep, cognitive function and brain MRI parameters from SABRE.

Discussion

Racial and ethnic differences can impact the relationships of cognitive function, sleep quality and brain structure in older adults. Earlier studies have highlighted higher prevalence of poor sleep among black individuals compared to white individuals. Genetic or epigenetic mechanisms may contribute to these variations. Socio-cultural and environmental factors, such as neighbourhood, migration, lifestyle, stress and perceived discrimination may influence sleep patterns. The aim of the study is to examine the ethnogeographic variations in sleep quality, cognitive performance and brain morphometry among Indians living in India, and South Asians and Europeans residing in the UK.

A nationwide study on sleep complaints and associated factors in older adults: ELSI-Brazil

Sleep problems, such as difficulty falling asleep, staying asleep, early awakening with failure to continue sleep, and altered sleep-wake cycle, are common in the general population. This cross-sectional study with 6,929 older adults (≥ 60 years) aimed to estimate the prevalence of different types of sleep problems, their associated factors, and the population-attributable fraction of associated factors among older adults. The outcome variables consisted of self-reported sleep problems: insomnia (initial, intermediate, late, and any type of insomnia), poor sleep quality, and daytime sleepiness. The independent variables were sociodemographic and behavioral characteristics and health conditions. The prevalence proportions were initial insomnia (49.1%), intermediate insomnia (49.2%), late insomnia (45.9%), any type of insomnia (58.6%), poor sleep quality (15.6%), and daytime sleepiness (38.4%). Female sex, presence of two or more chronic diseases, not eating the recommended amount of fruits and vegetables, and regular and bad/very bad self-rated health were positively associated with the sleep problems investigated. Consuming alcohol once a month or more was inversely associated with initial insomnia. Population attributable fraction estimates ranged from 3% to 19% considering two or more chronic diseases, not eating the recommended amount of fruits and vegetables, and regular and bad/very bad self-rated health. High prevalence of self-reported sleep problems was evinced in older adults. These results can be useful to guide public health services in the creation of informational, evaluative, and screening strategies for sleep problems in older Brazilian adults.

Mental and physical health pathways linking insomnia symptoms to cognitive performance 14 years later

STUDY OBJECTIVES

Insomnia may be a modifiable risk factor for later-life cognitive impairment. We investigated: (1) which insomnia symptoms are associated with subsequent cognitive functioning across domains; (2) whether insomnia-cognition associations are mediated by mental and physical health; and (3) whether these associations are modified by gender.

METHODS

Participants included 2595 adults ages 51-88 at baseline (Mage=64.00 ± 6.66, 64.5% women) in the Health and Retirement Study. The frequency of insomnia symptoms (difficulty initiating sleep, night time awakenings, early awakenings, and feeling unrested upon awakening) at baseline (2002) were quantified using a modified Jenkins Sleep Questionnaire. Cognition was assessed in 2016 via the Harmonized Cognitive Assessment Protocol and operationalized with factor scores corresponding to five domains. Depressive symptoms and vascular conditions in 2014 were assessed via self-report. Structural equation models estimated total, indirect, and direct effects of insomnia symptoms on subsequent cognition through depressive symptoms and vascular diseases, controlling for baseline sociodemographic and global cognition.

RESULTS

Frequent difficulty initiating sleep was associated with poorer episodic memory, executive function, language, visuoconstruction, and processing speed 14 years later (-0.06 ≤ β ≤ -0.04; equivalent to 2.2-3.4 years of aging). Depressive symptoms explained 12.3%-19.5% of these associations and vascular disease explained 6.3%-14.6% of non-memory associations. No other insomnia symptoms were associated with cognition, and no associations were modified by gender.

CONCLUSIONS

Difficulty initiating sleep in later life may predict future cognitive impairment through multiple pathways. Future research with longitudinal assessments of insomnia, insomnia treatments, and cognition is needed to evaluate insomnia as a potential intervention target to optimize cognitive aging.

Sleep disturbance predicts worse cognitive performance in subsequent years: A longitudinal population-based cohort study

BACKGROUND

Poor sleep is a potential modifiable risk factor for later life development cognitive impairment. The aim of this study is to examine if subjective measures of sleep duration and sleep disturbance predict future cognitive decline in a population-based cohort of 60, 66, 72 and 78-year-olds with a maximal follow up time of 18 years.

METHODS

This study included participants from the Swedish National Study on Ageing and Care - Blekinge, with assessments 2001-2021. A cohort of 60 (n = 478), 66 (n = 623), 72 (n = 662) and 78 (n = 548) year-olds, were assessed at baseline and every 6 years until 78 years of age. Longitudinal associations between sleep disturbance (sleep scale), self-reported sleep duration and cognitive tests (Mini Mental State Examination and the Clock drawing test) were examined together with typical confounders (sex, education level, hypertension, hyperlipidemia, smoking status, physical inactivity and depression).

RESULTS

There was an association between sleep disturbance at age 60 and worse cognitive function at ages 60, 66 and 72 years in fully adjusted models. The association was attenuated after bootstrap-analysis for the 72-year-olds. The items of the sleep scale most predictive of later life cognition regarded nightly awakenings, pain and itching and daytime naps. Long sleep was predictive of future worse cognitive function.

CONCLUSION

Sleep disturbance was associated with worse future cognitive performance for the 60-year-olds, which suggests poor sleep being a risk factor for later life cognitive decline. Questions regarding long sleep, waking during the night, pain and itching and daytime naps should be further explored in future research and may be targets for intervention.

Association of sleep with cognitive function during retirement transition: the Whitehall II study

STUDY OBJECTIVES

Sleep duration and difficulties have been shown to associate with cognitive function. This study examined how changes in sleep and in cognitive function are associated during retirement transition.

METHODS

The study population consisted of 2980 Whitehall II study participants, who retired during the follow-up, whose sleep was queried, and cognitive function measured (inductive reasoning and verbal memory) before and after retirement (follow-up 16 years). Using the last information on sleep before and the first after retirement, participants were categorized into constantly without (59%), increasing (13%), decreasing (11%), and constantly with (18%) sleep difficulties; and constantly short (26%), increasing (19%), decreasing (8.5%), and constantly mid-range (47%) sleep duration. Change in cognitive function during retirement transition was examined by sleep change groups using linear regression analyses with generalized estimating equations.

RESULTS

More pronounced decline in inductive reasoning during retirement transition was observed among participants with increasing sleep difficulties (-1.96, 95% CI -2.52 to -1.41) compared to those constantly without sleep difficulties (-1.25, 95% CI -1.52 to -0.98) and constantly with sleep difficulties (-1.26, 95% CI -1.75 to -0.92). Decreasing sleep difficulties (-0.64, 95% CI -0.86 to -0.43) were associated with a more pronounced decline in verbal memory when compared to constantly without sleep difficulties (-0.42, 95% CI -0.52 to -0.32) in post-retirement period. No statistically significant differences across sleep duration groups in cognitive function were observed.

CONCLUSIONS

Increasing and decreasing sleep difficulties may be associated with accelerated decline in cognitive function during retirement transition and post-retirement.

Sleep and Cognition: A Narrative Review Focused on Older Adults

Little is known regarding sleep's association with the traditional developmental course of late-life cognitive functioning. As the number of older adults increases worldwide, an enhanced understanding of age-related changes in sleep and cognition is necessary to slow decline and promote optimal aging. This review synthesizes the extant literature on sleep and cognitive function in healthy older adults, older adults with insomnia, and older adults with sleep apnea, incorporating information on the potential promising effects of treating poor sleep on cognitive outcomes in older adults. Unifying theories of the sleep-cognition association, possible mechanisms of action, and important unanswered questions are identified.

Are Sleep Complaints Related to Cognitive Functioning in Non-Central Nervous System Cancer? A Systematic Review

Patients with non-central nervous system (CNS) cancer frequently report cognitive complaints, that are recurrent and affect their quality of life. In order to improve supportive care of these cognitive difficulties, it is important to identify associated factors. Sleep disturbance is a good candidate to study, as patients with non-CNS cancer frequently report sleep disorders, and sleep plays a key role in cognitive functioning. The objective of the present systematic review was to summarize the results of studies evaluating the relationship between cognition and sleep in non-CNS cancer, and to highlight the need for further studies. PubMed [Medline] and Scopus databases were screened from April to November 2020 for studies published in English evaluating the association between cognition and sleep in adults with non-CNS cancer. The characteristics and risk of bias for each of the 30 included studies have been reported. Greater cognitive complaints in patients with non-CNS cancer were related to poorer self-reported sleep quality in almost all studies (n = 22/24). By contrast, around half of the studies reported a significant association between poorer neuropsychological performances and sleep complaints (n = 5/11). The studies were found to have several limitations, such as the lack of a control group, which would have shed the light on the period of occurrence of this association (e.g. after cancer diagnosis or after cancer treatments). Our review also identified factors that may influence the relationship between cognition and sleep. Recommendations are given for improving the methodology of future studies and extending the impact of their results.

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.

Severe sleep disturbance is associated with executive function impairment in patients with first-episode, treatment-naïve major depressive disorders

BACKGROUND

Sleep disturbance and executive function impairment are common in patients with major depressive disorder (MDD), though the relationship between the two remains unclear. We investigated this association in first-episode, treatment-naïve patients with MDD.

METHODS

We analyzed data from 242 patients with MDD. We divided the patients into 2 groups based on sleep disturbance severity and compared the executive function odds ratios between the groups.

RESULTS

A total of 121 pairs of patients were matched (age 39.4 ± 10.1, 70.2% female). After propensity score matching, the odds ratios for cognitive impairment in patients with MDD and severe sleep disturbance were 1.922 (1.068-3.459, P = 0.029, q = 0.044) in executive functioning; 2.023 (1.211-3.379, P = 0.007, q = 0.021) in executive shifting.

CONCLUSIONS

Sleep disturbance is associated with executive functioning impairment in first-episode, treatment-naïve patients with MDD. Severe sleep disturbance can be a marker and aid in recognizing executive function impairment in patients with first-episode treatment-naïve MDD. Severe sleep disturbance can be a potential modifiable factor to improve executive function in MDD, as well as an effective measurement to improve cognition for sleep symptom management that should be enforced at initial treatment of first-episode MDD. Further study is required to confirm our results.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT02023567 ; registration date: December 2013.

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.

The Impact of Optimized Daylight and Views on the Sleep Duration and Cognitive Performance of Office Workers

A growing awareness has recently emerged on the health benefits of exposure to daylight and views. Daylight exposure is linked to circadian rhythm regulation, which can have significant impacts on sleep quality and cognitive function. Views of nature have also been shown to impact emotional affect and performance. This study explores the impact of optimized daylight and views on the sleep and cognitive performance of office workers. Thirty knowledge workers spent one week working in each of two office environments with identical layouts, furnishings, and orientations; however, one was outfitted with electrochromic glass and the other with traditional blinds, producing lighting conditions of 40.6 and 316 equivalent melanopic lux, respectively. Participants in the optimized daylight and views condition slept 37 min longer as measured by wrist-worn actigraphs and scored 42% higher on cognitive simulations designed to test their higher order decision-making performance. Both sleep and cognitive function were impacted after one day in the space, yet the impacts became more significant over the course of the week. The positive effect of optimized daylight and views on cognitive function was comparable for almost all participants, while increases in sleep duration were significantly greater for those with the lowest baseline sleep duration. This study stresses the significance of designing with daylight in order to optimize the sleep quality and performance of office workers.

Cognitive functioning, sleep quality, and work performance in non-clinical burnout: The role of working memory

We investigated the relationship between cognitive functioning, work performance, and sleep in non-clinical burnout. In a working population, an online survey was conducted with additional online neuropsychological tests of varying complexity, measuring attention and different components of working memory, of which the coordinating subcomponent the ‘Central Executive’ is thought to be the most vulnerable to stress. Results indicate that non-clinical burnout is associated with more—though not severe—sleep problems, more depressive complaints, impaired work performance, and with both subjective and objective cognitive impairments. Compared with healthy respondents (N = 107), people with non-clinical burnout (N = 17) had a significantly poorer performance on the tests of the visuospatial sketchpad and the Central Executive of the working memory. Our study also indicates that more complex tests may be more sensitive in detecting cognitive dysfunction in non-clinical burnout. Furthermore, a relationship was found between dual-task performance and work performance. Regarding to sleep quality, in our sample of people with non-clinical burnout, there were no severe sleep problems. In the entire sample, however, insomnia was significantly related to subjective, but not objective, cognitive functioning, and also not to work performance.

Is Sleep Disruption a Cause or Consequence of Alzheimer's Disease? Reviewing Its Possible Role as a Biomarker

In recent years, the idea that sleep is critical for cognitive processing has gained strength. Alzheimer's disease (AD) is the most common form of dementia worldwide and presents a high prevalence of sleep disturbances. However, it is difficult to establish causal relations, since a vicious circle emerges between different aspects of the disease. Nowadays, we know that sleep is crucial to consolidate memory and to remove the excess of beta-amyloid and hyperphosphorilated tau accumulated in AD patients' brains. In this review, we discuss how sleep disturbances often precede in years some pathological traits, as well as cognitive decline, in AD. We describe the relevance of sleep to memory consolidation, focusing on changes in sleep patterns in AD in contrast to normal aging. We also analyze whether sleep alterations could be useful biomarkers to predict the risk of developing AD and we compile some sleep-related proposed biomarkers. The relevance of the analysis of the sleep microstructure is highlighted to detect specific oscillatory patterns that could be useful as AD biomarkers.

[Hypertension and insomnia]

Insomnia is frequently detected in patients with arterial hypertension (AH): from 19% to 47.9% of all cases according to epidemiological studies. On the other hand, the frequency of hypertension in patients with insomnia ranges from 21.4% to 50.2%, whereas in patients without insomnia, from 11.0% to 41.8%. In single studies in which patients with insomnia underwent ambulatory blood pressure monitoring (ABPM), these patients showed higher nocturnal blood pressure levels. Recent data suggests that insomnia is also a risk factor for hypertension. Among the pathogenetic mechanisms explaining the relationship between hypertension and insomnia, an increase in the activity of the main neuroendocrine stress systems, sympatho - adrenal and hypothalamic - pituitary - adrenal, and the frequent presence of concomitant anxiety disorders are discussed. To determine the sleep quality in patients with insomnia, the Pittsburgh Sleep Quality Index (PSQI) is most often used, patients with hypertension in a number of studies had higher total PSQI score compared to individuals with normal blood pressure. PSQI score correlates with systolic and diastolic blood pressure level, as well as with the presence of non - dipper blood pressure profile. Both hypertension and insomnia are associated with impaired cognitive functions. However, the relationship between cognitive impairment and insomnia is rather contradictory, which is most associated with the methodology for assessing cognitive functions and differences in the initial clinical and demographic characteristics of the examined patient population.

Association between insomnia and cognitive performance, gray matter volume, and white matter microstructure in cognitively unimpaired adults

BACKGROUND

Mounting evidence links poor sleep quality with a higher risk of late-life dementia. However, the structural and cognitive correlates of insomnia are still not well understood. The study aims were to characterize the cognitive performance and brain structural pattern of cognitively unimpaired adults at increased risk for Alzheimer's disease (AD) with insomnia.

METHODS

This cross-sectional study included 1683 cognitively unimpaired middle/late-middle-aged adults from the ALFA (ALzheimer and FAmilies) study who underwent neuropsychological assessment, T1-weighted structural imaging (n = 366), and diffusion-weighted imaging (n = 334). The World Health Organization's World Mental Health Survey Initiative version of the Composite International Diagnostic Interview was used to define the presence or absence of insomnia. Multivariable regression models were used to evaluate differences in cognitive performance between individuals with and without insomnia, as well as potential interactions between insomnia and the APOE genotype. Voxel-based morphometry and tract-based spatial statistics were used to assess between-group differences and potential interactions between insomnia and the APOE genotype in gray matter volume and white matter diffusion metrics.

RESULTS

Insomnia was reported by 615 out of 1683 participants (36.5%), including 137 out of 366 (37.4%) with T1-weighted structural imaging available and 119 out of 334 (35.6%) with diffusion-weighted imaging. Individuals with insomnia (n = 615) performed worse in executive function tests than non-insomniacs and displayed lower gray matter volume in left orbitofrontal and right middle temporal cortex, bilateral precuneus, posterior cingulate cortex and thalamus, higher gray matter volume in the left caudate nucleus, and widespread reduction of mean and axial diffusivity in right hemisphere white matter tracts. Insomnia interacted with the APOE genotype, with APOE-ε4 carriers displaying lower gray matter volumes when insomnia was present, but higher volumes when insomnia was not present, in several gray matter regions, including the left angular gyrus, the bilateral superior frontal gyri, the thalami, and the right hippocampus.

CONCLUSIONS

Insomnia in cognitively unimpaired adults at increased risk for AD is associated to poorer performance in some executive functions and volume changes in cortical and subcortical gray matter, including key areas involved in Alzheimer's disease, as well as decreased white matter diffusivity.

Effects of Brief Behavioral Treatment for Insomnia on Daily Associations between Self-Reported Sleep and Objective Cognitive Performance in Older Adults

OBJECTIVE

Behavioral treatments for insomnia improve sleep in older adults, but research documenting their effects on cognitive performance is mixed. We explored whether a brief behavioral treatment for insomnia (BBTi) impacts daily associations between sleep parameters and next day cognition.

METHODS

Sixty-two older adults (M_age = 69.45 years, SD = 7.71) with insomnia completed either 4 weeks of BBTi or self-monitoring control (SMC). At baseline, post-treatment, and 3 month follow-up, participants completed 14 days of diaries measuring sleep onset latency (SOL), wake after sleep onset (WASO), total sleep time (TST), and sleep efficiency (SE), as well as daily cognitive tests measuring processing speed (i.e., symbol digit modalities test, SDMT), and reasoning (i.e., letter series). At each time period, associations between sleep parameters and daily cognition, controlling for age, education, insomnia duration, use of sleep medications, and depression (i.e., Beck Depression Inventory-2^nd Edition scores), were examined through multilevel modeling.

RESULTS

At post-treatment, we observed an interactive fixed effect of treatment condition (i.e., BBTi/SMC) and TST on daily SDMT and letter series performance. For BBTi, longer TST was associated with better letter series performance, and did not predict SDMT performance. For SMC, longer TST was associated with worse SDMT, and was not associated with letter series performance. Greater WASO (regardless of group) was associated with better SDMT performance at post-treatment. Associations were not maintained at follow-up.

CONCLUSIONS

Sleep duration may play an important role in BBTi-related improvements in daily higher order cognition. Maintenance of these associations may be facilitated by booster sessions following post-treatment.

CLINICAL TRIAL IDENTIFIER

NCT02967185.

Insomnia in Older Adults

Purpose of Review

To evaluate and summarize recent research articles pertaining to insomnia in older adults that can guide healthcare providers on factors to consider when assessing and managing insomnia.

Recent Findings

Up to 75% of older adults experience symptoms of insomnia. Insomnia is associated with socioeconomic status, racial and ethnic classification, family relationships, medical and mental health disorders, cognitive function, and dementia. Although one-fifth of older adults are still prescribed sleep medications, cognitive behavioral therapy for insomnia is the first line treatment for insomnia, resulting in short-term and long-term benefits.

Summary

To manage insomnia safely and effectively, healthcare providers need to consistently assess for insomnia during baseline and annual assessments, evaluate medical and social factors associated with insomnia, minimize the use of sleep medications, and provide referrals to and/or collaborate with providers who perform cognitive behavioral therapy for insomnia. Insomnia screening is important as it facilitates early intervention with behavioral management, reduces the potential for pharmacological management, which increases fall risk in older adults, and enables further assessment and early identification of outcomes such as cognitive impairment.

Analysis of Sociodemographic and Psychological Variables Involved in Sleep Quality in Nurses

BACKGROUND

Sleep quality is related to health and quality of life and can lead to the development of related disorders. This study analyzed the sociodemographic and psychological factors related to sleep quality in nurses.

METHODS

The sample comprised 1094 nurses who were assessed according to the Pittsburgh Sleep Quality Index, the Rosenberg Self-esteem Questionnaire, the Goal Content for Exercise Questionnaire, the Brief Emotional Intelligence Inventory, and the Three-Factor Eating Questionnaire-R18.

RESULTS

The results confirm the impacts of diet, motivation for physical exercise, emotional intelligence, and overall self-esteem on sleep quality in nurses.

CONCLUSIONS

Sleep quality in healthcare professionals is vitally important for performance at work; therefore, appropriate strategies should be applied to improve it.

Neuropsychological Function Response to Nocturnal Blue Light Blockage in Individuals With Symptoms of Insomnia: A Pilot Randomized Controlled Study

OBJECTIVES

Insomnia is associated with neuropsychological dysfunction. Evidence points to the role of nocturnal light exposure in disrupted sleep patterns, particularly blue light emitted through smartphones and computers used before bedtime. This study aimed to test whether blocking nocturnal blue light improves neuropsychological function in individuals with insomnia symptoms.

METHODS

This study used a randomized, placebo-controlled crossover design. Participants were randomly assigned to a 1-week intervention with amber lenses worn in wrap-around frames (to block blue light) or a 1-week intervention with clear lenses (control) and switched conditions after a 4-week washout period. Neuropsychological function was evaluated with tests from the NIH Toolbox Cognition Battery at three time points: (1) baseline (BL), (2) following the amber lenses intervention, and (3) following the clear lenses intervention. Within-subjects general linear models contrasted neuropsychological test performance following the amber lenses and clear lenses conditions with BL performance.

RESULTS

Fourteen participants (mean(standard deviation, SD): age = 46.5(11.4)) with symptoms of insomnia completed the protocol. Compared with BL, individuals performed better on the List Sorting Working Memory task after the amber lenses intervention, but similarly after the clear lenses intervention (F = 5.16; p = .014; η2 = 0.301). A similar pattern emerged on the Pattern Comparison Processing Speed test (F = 7.65; p = 0.002; η2 = 0.370). Consideration of intellectual ability indicated that treatment with amber lenses "normalized" performance on each test from approximately 1 SD below expected performance to expected performance.

CONCLUSIONS

Using a randomized, placebo-controlled crossover design, we demonstrated improvement in processing speed and working memory with a nocturnal blue light blocking intervention among individuals with insomnia symptoms. (JINS, 2019, 25, 668-677).

Evaluating the role of orexins in the pathophysiology and treatment of depression: A comprehensive review

Orexins are neuropeptides that are postulated to play a central role in the regulation of the sleep-wake cycle, appetite, affect, and reward circuitry. The objectives of the current review are to comprehensively evaluate (1) the potential role of orexins in the pathophysiology of major depressive disorders (MDD) and (2) the orexin system as a novel target in the treatment of MDD. Dysfunction of the sleep-wake cycle is observed as a central feature of MDD pathophysiology. Orexin system disturbances produce sleep-wake dysfunction, as observed in MDD. Orexin antagonists have been shown to treat insomnia effectively without disrupting normal sleep architecture in both preclinical (e.g., animal models) and clinical studies. Orexin antagonists are generally safe, well-tolerated, and associated with an acceptable long-term adverse effect profile with relatively low propensity for tolerance or dependence. Orexin antagonists have also been shown to possess antidepressant-like properties in some animal models of MDD. Extant evidence indicates that orexin-modulating treatments exert pleiotropic effects on multiple neural systems implicated in the phenomenology of mood disorders and suggests orexins as a promising target for investigation and intervention in mood disorders. To date, no human clinical trials evaluating the antidepressant effects of orexin antagonists in MDD have been completed. Given the promising results from preclinical studies, clinical trials are merited to evaluate the antidepressant effects of orexin antagonists in MDD.

Predictors of Response to Ketamine in Treatment Resistant Major Depressive Disorder and Bipolar Disorder

Objectives: Extant evidence indicates that ketamine exerts rapid antidepressant effects in treatment-resistant depressive (TRD) symptoms as a part of major depressive disorder (MDD) and bipolar disorder (BD). The identification of depressed sub-populations that are more likely to benefit from ketamine treatment remains a priority. In keeping with this view, the present narrative review aims to identify the pretreatment predictors of response to ketamine in TRD as part of MDD and BD. Method: Electronic search engines PubMed/MEDLINE, ClinicalTrials.gov, and Scopus were searched for relevant articles from inception to January 2018. The search term ketamine was cross-referenced with the terms depression, major depressive disorder, bipolar disorder, predictors, and response and/or remission. Results: Multiple baseline pretreatment predictors of response were identified, including clinical (i.e., Body Mass Index (BMI), history of suicide, family history of alcohol use disorder), peripheral biochemistry (i.e., adiponectin levels, vitamin B12 levels), polysomnography (abnormalities in delta sleep ratio), neurochemistry (i.e., glutamine/glutamate ratio), neuroimaging (i.e., anterior cingulate cortex activity), genetic variation (i.e., Val66Met BDNF allele), and cognitive functioning (i.e., processing speed). High BMI and a positive family history of alcohol use disorder were the most replicated predictors. Conclusions: A pheno-biotype of depression more, or less likely, to benefit with ketamine treatment is far from complete. Notwithstanding, metabolic-inflammatory alterations are emerging as possible pretreatment response predictors of depressive symptom improvement, most notably being cognitive impairment. Sophisticated data-driven computational methods that are iterative and agnostic are more likely to provide actionable baseline pretreatment predictive information.

Integrative Review of the Relationship Between Sleep Disturbances and Episodic Memory in Older Adults

Impaired episodic memory in older adults has been linked to many factors. One of these factors is sleep disturbances, which are reported by more than 50% of older adults. The relationship between episodic memory and sleep disturbances remains unclear, however, because of the multiple types of measures of sleep and episodic memory used in previous studies. The purpose of this integrative literature review was to integrate and compare findings on this relationship in adults aged 65 years. An electronic search was conducted in PubMed, Cumulative Index to Nursing and Allied Health Literature, PsychINFO, and Medline for material published from the inception of the databases to December 2016. The literature search produced 13 data-based, peer-reviewed, and primary research articles that met eligibility criteria. The synthesized results from these articles provide evidence that older adults with 6-8 hr of self-reported total sleep time had better episodic memory than older adults with ≤5 hr or ≥9 hr of total sleep time. Shorter length and lower percentage of slow-wave sleep were associated with reduced episodic memory in older adults, but the results were controversial. Selection of different measurements and inconsistent variables across studies increased the difficulty of synthesizing and comparing the results. The diversity of covariates controlled in the included articles raise questions regarding which covariates should be controlled in such studies of sleep and episodic memory in older adults. The numerous study limitations were thus major barriers to understanding the relationship between sleep disturbances and episodic memory.

The effects of vortioxetine on cognitive performance in working patients with major depressive disorder: A short-term, randomized, double-blind, exploratory study

BACKGROUND

Major Depressive Disorder (MDD) is a complex disease characterized by emotional, physical and cognitive symptoms. We explored the efficacy of vortioxetine versus placebo on outcomes of cognition, functioning and mood symptoms in working patients with depression, using paroxetine as an active reference.

METHODS

Gainfully employed patients (18-65 years, N = 152) with MDD were randomized 1:1:1 to 8 weeks' double-blind, parallel treatment either with vortioxetine (10mg/day) or paroxetine (20mg/day), or with placebo. The primary efficacy measure was the Digit Symbol Substitution Test (DSST), analyzed using a mixed model for repeated measurements, and the key secondary efficacy measure was the University of San Diego Performance-based Skills Assessment - Brief (UPSA-B), analyzed using analysis of covariance (last observation carried forward).

RESULTS

At week 8, DSST and UPSA-B performance had improved relative to baseline in all treatment groups, with no statistically significant differences between treatment groups. While improvements in mood were comparable for vortioxetine and paroxetine, numerical improvements in cognitive performance (DSST) were larger with vortioxetine. Vortioxetine significantly improved overall cognitive performance and clinician-rated functioning relative to placebo. The majority of adverse events were mild or moderate, with nausea being the most common adverse event for vortioxetine.

LIMITATIONS

Small sample sizes implied limited statistical power.

CONCLUSION

This explorative study showed no significant differences versus placebo in DSST or UPSA-B performance at week 8. However, secondary results support vortioxetine as an effective and well-tolerated antidepressant, supporting an added benefit for cognition and functioning, which could have particular therapeutic relevance for the working patient population.

Prevalence of Internet Addiction in Medical Students: a Meta-analysis

OBJECTIVE

With the development of online learning, communication, and entertainment, the Internet has become an indispensable tool for university students. Internet addiction (IA) has emerged as a health problem and the prevalence of IA varies from country to country. To date, the global prevalence of IA in medical students remains unknown. The objective of this meta-analysis was to establish precise estimates of the prevalence of IA among medical students in different countries.

METHODS

The pooled prevalence of IA among medical students was determined by the random-effects model. Meta-regression and subgroup analysis were performed to identify potential factors that could contribute to heterogeneity.

RESULTS

The pooled prevalence of IA among 3651 medical students is 30.1% (95% confidence interval (CI) 28.5-31.8%, Z = -20.66, df = 9, τ ² = 0.90) with significant heterogeneity (I ² = 98.12). Subgroup analysis shows the pooled prevalence of IA diagnosed by the Chen's Internet Addiction Scale (CIAS) (5.2, 95% CI 3.4-8.0%) is significantly lower than Young's Internet Addiction Test (YIAT) (32.2, 95% CI 20.9-45.9%) (p < 0.0001). Meta-regression analyses show that the mean age of medical students, gender proportion and the severity of IA are not significant moderators.

CONCLUSIONS

In conclusion, this meta-analysis identified the pooled prevalence of IA among medical students is approximately five times than that of the general population. Age, gender, and severity of IA did not account for high heterogeneity in prevalence, but IA assessment questionnaire was a potential source of heterogeneity. Given the high prevalence of IA, medical teachers and medical school administrators should identify medical students who suffer from IA and refer them for intervention.

Sleep and Cognition in Older Adults

Increased age is associated with normative declines in both sleep and cognitive functioning. Although there are some inconsistencies in the literature, negative sleep changes are associated with worse cognitive functioning. This negative relationship holds true across normal-sleeping older adults, older adults with insomnia, older adults with sleep disordered breathing, cognitively healthy older adults, and older adults with dementia. There are mixed results regarding potential benefits of sleep treatments on cognitive functions; however, this line of research deserves added attention because the potential mechanisms of action are likely distinct from other interventions to improve cognition.

Sleep onset insomnia, daytime sleepiness and sleep duration in relationship to Toxoplasma gondii IgG seropositivity and serointensity

Toxoplasma gondii (T. gondii) infects central nervous tissue and is kept in relative dormancy by a healthy immune system. Sleep disturbances have been found to precipitate mental illness, suicidal behavior and car accidents, which have been previously linked to T. gondii as well. We speculated that if sleep disruption, particularly insomnia, would mediate, at least partly, the link between T. gondii infection and related behavioral dysregulation, then we would be able to identify significant associations between sleep disruption and T. gondii. The mechanisms for such an association may involve dopamine (DA) production by T. gondii, or collateral effects of immune activation necessary to keep T. gondii in check. Sleep questionnaires from 2031 Old Order Amish were analyzed in relationship to T. gondii-IgG antibodies measured by enzyme-linked immunosorbent assay (ELISA). Toxoplasma gondii seropositivity and serointensity were not associated with any of the sleep latency variables or Epworth Sleepiness Scale (ESS). A secondary analysis identified, after adjustment for age group, a statistical trend toward shorter sleep duration in seropositive men (p = 0.07). In conclusion, it is unlikely that sleep disruption mediates links between T. gondii and mental illness or behavioral dysregulation. Trending gender differences in associations between T. gondii and shorter sleep need further investigation.

Sleep and cognitive performance: cross-sectional associations in the UK Biobank

OBJECTIVE

The relationship between insomnia symptoms and cognitive performance is unclear, particularly at the population level. We conducted the largest examination of this association to date through analysis of the UK Biobank, a large population-based sample of adults aged 40-69 years. We also sought to determine associations between cognitive performance and self-reported chronotype, sleep medication use and sleep duration.

METHODS

This cross-sectional, population-based study involved 477,529 participants, comprising 133,314 patients with frequent insomnia symptoms (age: 57.4 ± 7.7 years; 62.1% female) and 344,215 controls without insomnia symptoms (age: 56.1 ± 8.2 years; 52.0% female). Cognitive performance was assessed by a touchscreen test battery probing reasoning, basic reaction time, numeric memory, visual memory, and prospective memory. Adjusted models included relevant demographic, clinical, and sleep variables.

RESULTS

Frequent insomnia symptoms were associated with cognitive impairment in unadjusted models; however, these effects were reversed after full adjustment, leaving those with frequent insomnia symptoms showing statistically better cognitive performance over those without. Relative to intermediate chronotype, evening chronotype was associated with superior task performance, while morning chronotype was associated with the poorest performance. Sleep medication use and both long (>9 h) and short (<7 h) sleep durations were associated with impaired performance.

CONCLUSIONS

Our results suggest that after adjustment for potential confounding variables, frequent insomnia symptoms may be associated with a small statistical advantage, which is unlikely to be clinically meaningful, on simple neurocognitive tasks. Further work is required to examine the mechanistic underpinnings of an apparent evening chronotype advantage in cognitive performance and the impairment associated with morning chronotype, sleep medication use, and sleep duration extremes.

The effect of melatonin on early postoperative cognitive decline in elderly patients undergoing hip arthroplasty: A randomized controlled trial

STUDY OBJECTIVE

The purpose of the present study was to investigate whether exogenous melatonin supplementation could ameliorate early postoperative cognitive decline (POCD) in aged patients undergoing hip arthroplasty with spinal anesthesia.

DESIGN

Prospective cohort study.

SETTING

Department of Anesthesiology, Jinling Hospital, Nanjing University, Nanjing, China.

PATIENTS

One hundred and thirty-nine patients with ASA I-III, older than 65yr of age (mean age: 74.5±5.5; gender: male 53 and female 86), scheduled for hip arthroplasty were included in the present study.

INTERVENTIONS

Patients were randomized to receive 1mg oral melatonin or placebo daily 1h before bedtime one day before surgery and for another 5 consecutive days postoperatively.

MEASUREMENTS

The subject assessment, including Mini-Mental State Examination (MMSE) score, subjective sleep quality, general well-being, postoperative fatigue, and visual analogue scale for pain were evaluated pre-operatively and at days 1, 3, 5, and 7 after surgery.

MAIN RESULTS

The MMSE score in the control group decreased significantly after surgery when compared with its own preoperative value or the melatonin group at days 1, 3, and 5. However, the MMSE score in the melatonin group remained unchanged during the 7days of monitoring. In addition, significant postoperative impairments of subjective sleep quality, general well-being, and fatigue were found in the control group when compared with the melatonin group.

CONCLUSION

Peroperative melatonin supplementation might improve early POCD, suggesting restoration of normal circadian function with good sleep quality may be one of the key factors in preventing or treating POCD.