Sleep-Disordered Breathing, Sleep Quality, and Mild Cognitive Impairment in the General Population

Association of obstructive sleep apnea and sleep quality with cognitive function: a study of middle-aged and elderly persons in India

INTRODUCTION

Symptoms of obstructive sleep apnea (OSA) and poor sleep quality affect around one in ten people in India. We aimed to determine if OSA symptoms and poor sleep quality are independently associated with cognition in middle-aged and elderly urban Indian populations.

METHODS

We studied the cross-sectional association between OSA symptoms (by Berlin Questionnaire), poor sleep quality (by Pittsburgh Sleep Quality Index), and cognitive function in adults ≥ 50 years. Using a standard neuropsychological battery for cognitive function, a G-factor was derived as the first rotated principal component assessing domains of information processing, memory, and executive function. The associations of exposures with cognitive measures were modeled using linear regression, adjusted for metabolic risk factors, lifestyle factors, and psychosocial problems, followed by stratified analysis by decadal age group.

RESULTS

A total of 7505 adults were enrolled. Excluding those with MMSE < 26 (n 710), of 6795 individuals (49.2% women), mean (SD) age 64.2 (9.0) years, 38.3% had high risk of OSA symptoms, and 15.9% had poor sleep quality. OSA symptoms were negatively associated with cognitive domains of information processing (adjusted beta coefficient of z-score - 0.02, p-value 0.006), memory (- 0.03, 0.014), and G-factor (- 0.11, 0.014) in full-model. Stratified analysis by age group showed significant adverse effects of OSA symptoms on cognition for middle-aged people (50-60 years) (- 0.26, 0.001), but not in later age groups. Poor sleep quality was also associated with lower cognitive scores for G-factor (- 0.48, < 0.001), memory (- 0.08, 0.005), and executive domains (- 0.12, < 0.001), but not with information domain.

CONCLUSION

The findings suggest that both symptoms of OSA and poor sleep quality have a direct adverse impact on cognition in an Indian setting. A modest effect of age on the relationship of OSA and cognition was also observed.

The Relation of Sleep Characteristics and Cognitive Impairment in Community-Dwelling Middle-Aged and Older Adults: Ardakan Cohort Study on Aging (ACSA)

Introduction

The rise in the elderly population has brought attention to mild cognitive impairment (MCI). Sleep disorders also affect many older adults, indicating an important area of research for disturbed sleep and faster brain aging. This population-based study aimed to investigate the association of several sleep indicators with cognitive performance.

Methods

This cross-sectional study focused on adults over 50 in the Ardakan Cohort Study on Aging (ACSA). MCI was evaluated using the Mini-Mental State Examination (MMSE) and the Abbreviated Mental Test score (AMTS) in literate and illiterate individuals. Sleep characteristics were collected using the Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale, and Berlin questionnaire. The logistic regression models were used to analyze the data.

Results

Overall, 3,380 literate and 1,558 illiterate individuals were included. In both groups, participants with MCI had a significantly higher PSQI global score (p < 0.05). Also, among the literate individuals, a significantly higher risk of having sleep-disordered breathing and poor sleep quality was observed in participants with MCI (p < 0.05). In illiterate individuals, higher sleep latency than 15 min increased odds of MCI (p < 0.05). However, after adjusting for all variables, only literate individuals with a sleep duration of more than 8 h had 66 percent increased odds of having MCI (p = 0.033).

Conclusion

Sleep duration might be associated with cognitive function in the older Iranian population. Our findings underscore the importance of considering sleep patterns in relation to cognitive health.

Obstructive Sleep Apnea Among Patients with Mild Cognitive Impairment

Background

Obstructive sleep apnea (OSA) is associated with cognitive disorders, but little is known about prevalence of co-occurring OSA and mild cognitive impairment (MCI) as well as about co-occurring OSA and Alzheimer's disease (AD). Pathophysiological models integrating OSA, cognitive deficits and neurodegeneration remain speculative. Findings in this area could contribute to the knowledge about pathophysiological processes in cognitive disorders and neurodegenerative processes, be helpful for the diagnosis of cognitive disorders and provide approaches for the treatment of cognitive disorders.

Objective

Examining the prevalence of OSA and patterns of cognitive deficits as well as AD biomarker profiles associated with OSA in a cohort of 104 MCI patients.

Methods

Assessments used include: respiratory polygraphy, The Consortium to Establish a Registry for Alzheimer's Disease Neuropsychological Battery (CERAD NB), Tau, phosphoTau181, amyloid-β-1-42/1-40, 18F-fluorodeoxyglucose positron emission tomography (F18-FDG-PET).

Results

Prevalence of OSA of any severity: 58,7% (Apnea Hypopnea Index (AHI)≥5/h), OSA in a moderate-to-severe extent (AHI≥15/h): 25%. Only 13.1% of MCI patients with OSA reported daytime sleepiness. MCI-OSA patients showed no specific neuropsychological pattern. Presence of OSA was not associated with specific AD biomarker profiles in the whole study group besides a positive association between AD positivity in an AD biomarker sub cohort.

Conclusions

OSA is highly prevalent in patients with MCI. It might often remain undiagnosed as only a small number of MCI-OSA patients report daytime sleepiness. OSA could contribute to MCI symptoms and even to AD pathology. Further research is needed to validate these findings and to investigate possible pathophysiological relationships between OSA and MCI as well as between OSA and AD.

Association Between Occupational Stress and Sleep Quality: A Systematic Review

Occupational stress and sleep quality are prevalent issues that can impact the physical and mental well-being of adults. An association between occupational stress and sleep quality has been found. However, this association is not entirely the same across different occupational groups. Additionally, variations are present in the research design and instruments employed.This systematic review aims to investigate the association between these two factors and identify gaps and limitations in current research. Articles published between January 1, 2011, and December 31, 2022, were retrieved from the WOS, Scopus, and PubMed databases. Out of 1225 articles, 38 studies met the predetermined inclusion and exclusion criteria and were included in the review. In the study, research designs, samples, instruments, and associations between occupational stress and sleep quality were statistically analyzed.These studies encompassed a diverse range of occupations, including both blue-collar and white-collar workers. Cross-sectional study is the most common research method. The Pittsburgh Sleep Quality Index (PSQI) was the most frequently utilized tool for assessing sleep quality, while there was a wide variety of measurement tools employed to assess occupational stress. The association between occupational stress and sleep quality consistently demonstrated a negative association, although the specific dimensions varied among studies. Moreover, several other factors were identified to have direct or indirect effects on occupational stress and sleep quality. For future research in this field, we propose four recommendations: (1) Consider utilizing objective measures to assess occupational stress and sleep quality. (2) Employ controlled experiments to further validate the causal relationship between occupational stress and sleep quality. (3) Investigate occupational groups that have received less attention. (4) Take into account the potential influence of other factors on occupational stress and sleep quality.

Hippocampal injections of soluble amyloid-beta oligomers alter electroencephalographic activity during wake and slow-wave sleep in rats

BACKGROUND

Soluble amyloid-beta oligomers (Aβo) begin to accumulate in the human brain one to two decades before a clinical diagnosis of Alzheimer's disease (AD). The literature supports that soluble Aβo are implicated in synapse and neuronal losses in the brain regions such as the hippocampus. This region importantly contributes to explicit memory, the first type of memory affected in AD. During AD preclinical and prodromal stages, people are also experiencing wake/sleep alterations such as insomnia (e.g., difficulty initiating sleep, decreased sleep duration), excessive daytime sleepiness, and sleep schedule modifications. In addition, changes in electroencephalographic (EEG) activity during wake and sleep have been reported in AD patients and animal models. However, the specific contribution of Aβo to wake/sleep alterations is poorly understood and was investigated in the present study.

METHODS

Chronic hippocampal injections of soluble Aβo were conducted in male rats and combined with EEG recording to determine the progressive impact of Aβ pathology specifically on wake/sleep architecture and EEG activity. Bilateral injections were conducted for 6 consecutive days, and EEG acquisition was done before, during, and after Aβo injections. Immunohistochemistry was used to assess neuron numbers in the hippocampal dentate gyrus (DG).

RESULTS

Aβo injections did not affect the time spent in wakefulness, slow wave sleep (SWS), and paradoxical sleep but altered EEG activity during wake and SWS. More precisely, Aβo increased slow-wave activity (SWA; 0.5-5 Hz) and low-beta activity (16-20 Hz) during wake and decreased theta (5-9 Hz) and alpha (9-12 Hz) activities during SWS. Moreover, the theta activity/SWA ratio during wake and SWS was decreased by Aβo. These effects were significant only after 6 days of Aβo injections and were found with alterations in neuron counts in the DG.

CONCLUSIONS

We found multiple modifications of the wake and SWS EEG following Aβo delivery to the hippocampus. These findings expose a specific EEG signature of Aβ pathology and can serve the development of non-invasive and cost-effective markers for the early diagnosis of AD or other amyloid-related diseases.

The Role of Sleep in Cognitive Function: The Value of a Good Night's Rest

As a universal, evolutionarily conserved phenomenon, sleep serves many roles, with an integral role in memory. This interplay has been examined in a variety of research. The purpose of this article will be to review the literature of sleep, aging, cognition, and the impact of two common clinical conditions (obstructive sleep apnea and insomnia) on cognitive impairment. This article will review data from meta-analyses, population studies, smaller cohort studies, neuropsychological studies, imaging, and bench data. Considerations are given to the current data trends and their limitations. This paper will explore the impact of sleep on cognitive impairment. Finally, we will conclude with integrating the separate mechanisms towards more generalized common pathways: disruption of sleep quality and reduction in sleep quantity lead to excessive neuronal activity without sufficient time for homeostasis. Sleep apnea and chronic insomnia can lead to oxidative stress and neuronal damage. These changes predispose and culminate in the development of cognitive impairment.

The prevalence of obstructive sleep apnoea risk factors in individuals with cognitive impairment: south London cross-sectional study

AIMS AND METHOD

We aimed to determine the prevalence of risk factors for obstructive sleep apnoea (OSA) in patients with mild cognitive impairment (MCI) or dementia. Using patient records across a 5 year period, we identified 16 855 patients with dementia or MCI. We gave scores for keywords relating to each modified STOP BANG parameter in patient progress notes. Based on individual scores, we stratified the population into groups with low, intermediate and high risk of OSA.

RESULTS

Our population had a high prevalence of risk factors and consequently high risk scores for OSA (18.21% high risk). Parameters directly related to sleep had a low prevalence.

CLINICAL IMPLICATIONS

The risk of developing or having OSA is high among patients with MCI and dementia. Low sleep parameter frequency probably suggests poor documentation of sleep rather than true prevalence. Our findings support the implementation of the STOP BANG or a similar screening tool as a standardised method to identify OSA risk in memory clinics.

Sleep Quality and Aging: A Systematic Review on Healthy Older People, Mild Cognitive Impairment and Alzheimer’s Disease

Aging is characterized by changes in the structure and quality of sleep. When the alterations in sleep become substantial, they can generate or accelerate cognitive decline, even in the absence of overt pathology. In fact, impaired sleep represents one of the earliest symptoms of Alzheimer’s disease (AD). This systematic review aimed to analyze the studies on sleep quality in aging, also considering mild cognitive impairment (MCI) and AD. The review process was conducted according to the PRISMA statement. A total of 71 studies were included, and the whole sample had a mean age that ranged from 58.3 to 93.7 years (62.8–93.7 healthy participants and 61.8–86.7 pathological populations). Of these selected studies, 33 adopt subjective measurements, 31 adopt objective measures, and 10 studies used both. Pathological aging showed a worse impoverishment of sleep than older adults, in both subjective and objective measurements. The most common aspect compromised in AD and MCI were REM sleep, sleep efficiency, sleep latency, and sleep duration. These results underline that sleep alterations are associated with cognitive impairment. In conclusion, the frequency and severity of sleep disturbance appear to follow the evolution of cognitive impairment. The overall results of objective measures seem more consistent than those highlighted by subjective measurements.

Poor sleep quality is negatively associated with low cognitive performance in general population independent of self-reported sleep disordered breathing

BACKGROUND

Sleep disordered breathing (SDB) plays a significant role in both sleep quality and cognition and whether it has an impact on the relationship between above two factors remains to be clear. The study aimed to explore the association between sleep quality and cognitive performance in general population by considering influence of sleep disordered breathing (SDB).

METHODS

In this cross-sectional study, we enrolled subjects aged ≥ 18 years using a multi-stage random sampling method. Cognitive status was assessed using Mini Mental State Examination (MMSE) questionnaire, sleep quality using Pittsburgh Sleep Quality Index (PSQI) and SDB was assessed using No-SAS scale, respectively. Multi-variable logistic regression was applied to examine the association of sleep quality and cognitive performance. Subgroup analyses were performed in different age groups, and in those with and without SDB.

RESULTS

Finally, 30,872 participants aged 47.5 ± 13.8 years with 53.5% women were enrolled, of whom 32.4% had poor sleep quality and 18.6% had low cognitive performance. Compared with good sleepers, subjects with poor sleep quality exhibited significantly higher presence of low cognitive performance (23.7% vs 16.2%, P < 0.001). Poor sleepers revealed 1.26 (95%CI: 1.16,1.36), 1.26 (1.08,1.46) and 1.25 (1.14,1.37) fold odds for low cognitive performance in general population and in subjects with and without self-reported SDB respectively. Stratified by age and SDB, the association was observed in young and middle-aged group without SDB (OR = 1.44, 95%CI: 1.30,1.59) and in the elderly group with SDB (OR = 1.30, 95%CI: 1.07,1.58).

CONCLUSIONS

Sleep quality is in a negative association with cognitive performance in general population independent of SDB, implying improvement of sleep disturbances is a potential objective of intervention strategies for cognitive protection at population level.

Distinguishing the Associations Between Evening Screen Time and Sleep Quality Among Different Age Groups: A Population-Based Cross-Sectional Study

OBJECTIVE

The age differences in the association between screen time and sleep problems have been implied in many studies, and this study aims to distinguish the associations between evening screen time and sleep quality among different age groups.

METHODS

This is a population-based, cross-sectional study among community residents aged ≥18 years in China. A total of 21,376 valid questionnaires were analyzed. Sleep quality was measured by the Pittsburgh Sleep Quality Index. Averaged evening screen time (AEST), sociodemographic information, and health-related behaviors were also evaluated in this study.

RESULTS

In the 18-to-34-year age group, compared with people without AEST, ≤1 h/day (β = 0.34, p < 0.05) and >3 h/day (β = 1.05, p < 0.001) of AEST were significantly associated with poor sleep quality, and a reverse S-shaped relationship for this association was shown. In the 35-to-49-year and 50-to-64-year age groups, ≤1 h/day (β = 0.43 and 0.36, both p < 0.001), ≤2 h/day (β = 0.43 and 0.31, p < 0.001 and p < 0.01), ≤3 h/day (β = 0.62 and 0.61, both p < 0.001), and >3 h/day (β = 1.55 and 1.88, both p < 0.001) of AEST were positively associated with poor sleep quality. In the 65-year-and-older age group, a J-shaped relationship was found, and ≤3 h/day (β = 0.82, p < 0.001) and >3 h/day (β = 1.84, p < 0.001) of AEST were associated with poor sleep quality.

CONCLUSION

Associations between AEST and sleep quality among different age groups are different. In the 18-to-34-year and 65-year-and-older age groups, acceptable AEST is not related to sleep quality. In the 35-to-49-year and 50-to-64-year age groups, AEST was harmful to sleep quality.

Relationship between Resting State Heart Rate Variability and Sleep Quality in Older Adults with Mild Cognitive Impairment

Sleep problems can be caused by psychological stress but are also related to cardiovascular and neurodegenerative diseases. Improving lifestyle behaviors, such as good sleep hygiene, can help to counteract the negative effects of neurodegenerative diseases and to improve quality of life. The purpose of this cross-sectional study was to investigate the relationship between subjectively reported measures of sleep quality (via Pittsburgh Sleep Quality Index (PSQI)) and objective measures of cardiac autonomic control (via resting state heart rate variability (HRV)) among individuals with mild cognitive impairment (MCI). The PSQI and resting state HRV data of 42 MCI participants (69.0 ± 5.5; 56-80 years) were analyzed. Nineteen of the participants reported poor sleep quality (PSQI score > 5). Good sleepers showed higher resting heart rate than bad sleepers (p = 0.037; ES = 0.670). Correlation analysis showed a significant correlation between the parameter HF nu and sleep efficiency, contrasting the expected positive association between reduced HRV and poor sleep quality in healthy and individuals with specific diseases. Otherwise, there were no significances, indicating that measures of subjective sleep quality and resting HRV were not related in the present sample of MCI participants. Further research is needed to better understand the complex relationship between HRV and lifestyle factors (e.g., sleep) in MCI.

Cognition and 20-year subsequent sleep disturbances

INTRODUCTION

There is a paucity of data exploring the extent that preclinical cognitive changes are predictive of subsequent sleep outcomes.

METHODS

Logistic regression models were used to evaluate data from a cohort of 196 African American adults who had measures of cognitive function assessed at 2 time points during a 20-year period across the mid- to late-life transition. Cognitive testing included the Delayed Word Recall, the Digit Symbol Substitution, and the Word Fluency tests, which were summarized as a composite cognitive z-score. Sleep apnea was measured by in-home sleep apnea testing and sleep duration and quality were derived from 7-day wrist actigraphy at the end of the study period.

RESULTS

A one standard deviation (SD) lower composite cognitive z-score at baseline was significantly associated with greater odds of low sleep efficiency (<85%) (odds ratio [OR] = 1.85, 95% confidence interval [CI] = 1.13, 3.04) and greater odds of increased wakefulness after sleep onset time (WASO; >60 minutes) (OR = 1.65, 95% CI = 1.05, 2.60) in adjusted models. A one SD faster rate of cognitive decline over the study period was significantly associated with greater odds of low sleep efficiency (OR = 1.68, 95% CI = 1.04, 2.73), greater odds of sleep fragmentation (>35%); (OR = 1.73, 95% CI = 1.05, 2.85), and greater odds of increased WASO (OR = 1.85, 95% CI = 1.15, 2.95) in adjusted models. Neither baseline cognitive z-score nor rate of cognitive decline was associated with sleep apnea or the total average sleep duration.

CONCLUSION

Cognition at baseline and change over time predicts sleep quality and may reflect common neural mechanisms and vulnerabilities.

Impact of shift work on the risk of depression

We studied the association between shift work and depressive symptoms in the prospective Heinz Nixdorf Recall Study, considering various demographic, lifestyle and work-related factors. Depressive symptoms were assessed using the Center for Epidemiologic Studies-Depression (CES-D)-Scale (≥17 points defined as high symptoms) and the Patient Health Questionnaire (PHQ) with a cutoff ≥9, or prescription of an anti-depressant. The definition of shift work included work hours outside 7:00 to 18:00, whereas night work was defined as a shift including work between 0:00 and 5:00. Poisson regression with robust error variances was calculated to estimate relative risks (RR) and 95% confidence intervals (CI), adjusted for age at follow-up, diurnal preference, monthly household income and education. Analyses were stratified by sex. We performed various sensitivity and stratified analyses to test the robustness of our results. At baseline, 1,500 gainfully employed subjects, 45-73 years of age and without a history of depression, were included. Until the 5-year follow-up, 896 participants were observed, and 486 participants survived through the 10-year follow-up. Although most analyses did not reach the level of formal statistical significance, women working night shifts tended to show increased relative risks for depressive symptoms according to the PHQ (RR = 1.78; 95% CI 0.71-4.45), in particular when working night shifts for ≥20 years (RR = 2.70; 95% CI 0.48-15.4). Stratification by age group revealed no increased risks among women above 60 years of age. Stratified analyses indicated that over-commitment was associated with higher risks for depressive symptoms among women (RR = 4.59; 95% CI 0.95-22.2 in the CES-D and RR = 12.7; 95% CI 2.89-56.1 in the PHQ). Exclusion of subgroups for the purpose of sensitivity analyses generally strengthened associations in women, whereas little evidence for an increased risk of depression remained among male shift workers. In summary, negative effects on depression were suggested among female shift workers, although results were based on small numbers. Among men, we did not identify consistently increased risks for depressive symptoms in relation to shift work.

Comparison of knowledge level and attitude towards obstructive sleep apnoea amongst dental and medical undergraduate students of Universiti Sains Malaysia

BACKGROUND

Sleep apnoea is a diagnosed condition in which appurtenances interrupt breathing whilst sleeping. The consequence of obstructive sleep apnoea (OSA) includes road traffic accidents due to drowsiness, systemic hypertension, heart disease, diabetes mellitus and neurocognitive disorders. This condition extends the duration of recovery phase after traumatic brain injury.

OBJECTIVE

This study was intended to assess the knowledge and attitude towards OSA and compare it among dental and medical undergraduate students of University Sains Malaysia (USM).

METHODS

In this study, a total of 216 clinical undergraduate students (36 from each year; 108 from medical and 108 from dental school) of University Sains Malaysia (USM) Health campus were recruited for the study by non-probability stratified random sampling method. Total study period was October 2017 to October 2018. A self-administered questionnaire was used to assess the sociodemographic status and OSAKA questionnaire was used to assess knowledge and attitude regarding sleep apnoea of the respondents. Descriptive analysis was carried out to assess the knowledge and attitude of OSA amongst dental and medical undergraduate students of USM. The Mann-Whitney U test was carried out to compare the knowledge and attitude of OSA amongst dental and medical undergraduate students of USM.

RESULTS

Our study findings revealed that 0.9 %and 6.5 %of the dental undergraduate students and medical undergraduate students could answer all the questions correctly regarding knowledge of OSA. Based on the assessment of the difference between medical and dental students in terms of knowledge towards OSA patients, significant difference was observed at the significance level of 95%, where p < 0.05 but no difference found in attitude towards OSA. However, significant difference was found towards attitude on treating OSA patients p < 0.05.

CONCLUSIONS

A difference was observed in the knowledge and attitude on OSA between dental and medical undergraduate students in USM; however, medical undergraduate students had better knowledge and attitude towards OSA than dental students.

The Importance of Diagnosing and the Clinical Potential of Treating Obstructive Sleep Apnea to Delay Mild Cognitive Impairment and Alzheimer's Disease: A Special Focus on Cognitive Performance

Obstructive sleep apnea (OSA) is a highly frequent sleep disorder in the middle-aged and older population, and it has been associated with an increased risk of developing cognitive decline and dementia, including mild cognitive impairment (MCI) and Alzheimer's disease (AD). In more recent years, a growing number of studies have focused on: 1) the presence of OSA in patients with MCI or AD, 2) the link between OSA and markers of AD pathology, and 3) the role of OSA in accelerating cognitive deterioration in patients with MCI or AD. Moreover, some studies have also assessed the effects of continuous positive airway pressure (CPAP) treatment on the cognitive trajectory in MCI and AD patients with comorbid OSA. This narrative review summarizes the findings of studies that analyzed OSA as a risk factor for developing MCI and/or AD in the middle-aged and older populations with a special focus on cognition. In addition, it describes the results regarding the effects of CPAP treatment in hampering the progressive cognitive decline in AD and delaying the conversion to AD in MCI patients. Considering the importance of identifying and treating OSA in patients with MCI or AD in order to prevent or reduce the progression of cognitive decline, further larger and adequately powered studies are needed both to support these findings and to set programs for the early recognition of OSA in patients with cognitive impairment.

Obstructive Sleep Apnea and Cognitive Decline: A Review of Potential Vulnerability and Protective Factors

Around 40% of dementia risk is attributable to modifiable risk factors such as physical inactivity, hypertension, diabetes and obesity. Recently, sleep disorders, including obstructive sleep apnea (OSA), have also been considered among these factors. However, despite several epidemiological studies investigating the link between OSA and cognitive decline, there is still no consensus on whether OSA increases the risk of dementia or not. Part of the heterogeneity observed in previous studies might be related to some individual characteristics that modulate the association between OSA and cognitive decline. In this narrative review, we present these individual characteristics, namely, age, sex, menopause, obesity, diabetes mellitus, hypertension, cardiovascular diseases, smoking, excessive alcohol consumption, depression, air pollution, Apolipoprotein E ε4 allele, physical activity, and cognitive reserve. To date, large cohort studies of OSA and cognitive decline tended to statistically control for the effects of these variables, but whether they interact with OSA to predict cognitive decline remains to be elucidated. Being able to better predict who is at risk of cognitive decline when they have OSA would improve clinical management and treatment decisions, particularly when patients present relatively mild OSA.

The role of sleep disturbances in cognitive function and depressive symptoms among community-dwelling elderly with sleep complaints

OBJECTIVE

The relationships between sleep problems, cognitive impairments, and depression have been established in the aging population. However, less is known about the role of late-life onset insomnia and sex involved in these dyad or tripartite relationships. This study aimed to consider onset age of insomnia and sex in the relationship between sleep parameters, cognition and depression among older adults with current insomnia complaints.

METHOD

A multistep sampling method was adopted to recruit participants with current insomnia complaints in China in 2018. Sleep measures include onset age of insomnia (64 years old or before vs during/after 65), three factors from insomnia severity index (ISI; nighttime, daytime, and perception), excessive daytime sleepiness, and sleep duration. Outcome measures were mini-mental state examination (MMSE) and center for epidemiologic studies depression scale (CESD).

RESULTS

The average age of older adults was 75 (SD = 7.1). Among them, 62% participants are female. In general, older aged, female, late-life onset insomnia as well as interaction of sex * onset age of insomnia were significantly associated with poorer cognition. Yet, age, sex, and onset age of insomnia were not significant indicators for depression. For female participants, later onset of insomnia, nighttime symptoms of insomnia, excessive daytime sleepiness and depression were risk factors for cognitive decline. Nevertheless, only daytime sleepiness, together with depression, were found positively associated with male participants' cognitive decline.

CONCLUSIONS

There were robust associations between daytime sleepiness, depressive symptoms, and poor cognitive performance. More importantly, late-life onset insomnia was particularly indicative for poor cognitive performance among female older adults. Future study should emphasize the specific mechanism involved in changes of sleep patterns in the development of cognitive impairment among older adults. Sex differences in the relationship between onset age of insomnia and cognition also require further attention.

Early Detection of Mild Cognitive Impairment With In-Home Sensors to Monitor Behavior Patterns in Community-Dwelling Senior Citizens in Singapore: Cross-Sectional Feasibility Study

Background

Dementia is a global epidemic and incurs substantial burden on the affected families and the health care system. A window of opportunity for intervention is the predementia stage known as mild cognitive impairment (MCI). Individuals often present to services late in the course of their disease and more needs to be done for early detection; sensor technology is a potential method for detection.

Objective

The aim of this cross-sectional study was to establish the feasibility and acceptability of utilizing sensors in the homes of senior citizens to detect changes in behaviors unobtrusively.

Methods

We recruited 59 community-dwelling seniors (aged >65 years who live alone) with and without MCI and observed them over the course of 2 months. The frequency of forgetfulness was monitored by tagging personal items and tracking missed doses of medication. Activities such as step count, time spent away from home, television use, sleep duration, and quality were tracked with passive infrared motion sensors, smart plugs, bed sensors, and a wearable activity band. Measures of cognition, depression, sleep, and social connectedness were also administered.

Results

Of the 49 participants who completed the study, 28 had MCI and 21 had healthy cognition (HC). Frequencies of various sensor-derived behavior metrics were computed and compared between MCI and HC groups. MCI participants were less active than their HC counterparts and had more sleep interruptions per night. MCI participants had forgotten their medications more times per month compared with HC participants. The sensor system was acceptable to over 80% (40/49) of study participants, with many requesting for permanent installation of the system.

Conclusions

We demonstrated that it was both feasible and acceptable to set up these sensors in the community and unobtrusively collect data. Further studies evaluating such digital biomarkers in the homes in the community are needed to improve the ecological validity of sensor technology. We need to refine the system to yield more clinically impactful information.

Associations between self-reported sleep characteristics and incident mild cognitive impairment: The Heinz Nixdorf Recall Cohort Study

Associations of sleep characteristics with mild cognitive impairment (MCI) have been examined in cross-sectional, but rarely in longitudinal studies. Incident MCI and sleep characteristics were assessed in 1,890 participants of the first and second follow-up of the Heinz Nixdorf Recall study, a population-based cohort study in Germany (age at first follow-up 50-80 years, mean follow-up 5.2 years). MCI was assessed with extensive cognitive tests. Sleep questionnaires including PSQI (Pittsburgh Sleep Quality Index) were used to assess sleep quality, sleep disturbances, time asleep, and time in bed. Relative risks (RR) of developing MCI when exposed to sleep characteristics were assessed in regression models adjusted for sociodemographic and cardiovascular risk factors. Poor sleep quality (PSQI > 5) (RR = 1.43, 95% CI: 1.12-1.82, fully adjusted, reference: PSQI ≤ 5) and difficulties initiating sleep (almost nightly versus never) (RR = 1.40, 0.94-2.08) were associated with incident MCI. For time in bed, the risk of MCI was increased for ≤ 5 hours (RR = 2.86, 1.24─6.60, reference:7 to <8 hours). In this longitudinal study with older participants, MCI risk was increased in persons with poor sleep quality, difficulties initiating sleep, and short time in bed.

Obstructive sleep apnea, cognition and Alzheimer's disease: A systematic review integrating three decades of multidisciplinary research

Increasing evidence links cognitive-decline and Alzheimer's disease (AD) to various sleep disorders, including obstructive sleep apnea (OSA). With increasing age, there are substantial differences in OSA's prevalence, associated comorbidities and phenotypic presentation. An important question for sleep and AD researchers is whether OSA's heterogeneity results in varying cognitive-outcomes in older-adults compared to middle-aged adults. In this review, we systematically integrated research examining OSA and cognition, mild cognitive-impairment (MCI) and AD/AD biomarkers; including the effects of continuous positive airway pressure (CPAP) treatment, particularly focusing on characterizing the heterogeneity of OSA and its cognitive-outcomes. Broadly, in middle-aged adults, OSA is often associated with mild impairment in attention, memory and executive function. In older-adults, OSA is not associated with any particular pattern of cognitive-impairment at cross-section; however, OSA is associated with the development of MCI or AD with symptomatic patients who have a higher likelihood of associated disturbed sleep/cognitive-impairment driving these findings. CPAP treatment may be effective in improving cognition in OSA patients with AD. Recent trends demonstrate links between OSA and AD-biomarkers of neurodegeneration across all age-groups. These distinct patterns provide the foundation for envisioning better characterization of OSA and the need for more sensitive/novel sleep-dependent cognitive assessments to assess OSA-related cognitive-impairment.

Sleep quality and cognitive impairment in older Chinese: Guangzhou Biobank Cohort Study

BACKGROUND

evidence concerning the relationship between sleep quality and cognitive impairment is limited and inconsistent.

OBJECTIVE

to examine the association of sleep quality with memory impairment and poor cognitive function in a large sample of older Chinese.

METHODS

15,246 participants aged 50+ years of the Guangzhou Biobank Cohort Study who attended the second physical examination from 2008 to 2012 were included. Sleep quality was assessed using Pittsburgh Sleep Quality Index (PSQI), and cognitive performance was assessed using both Delayed Word Recall Test (DWRT) and Mini-Mental State Examination (MMSE). Memory impairment was defined by DWRT score < 4 and poor cognitive function by MMSE score < 25.

RESULTS

after adjusting for potential confounders, lower habitual sleep efficiency was associated with a higher risk of memory impairment and poor cognitive function with a dose-response pattern (both P for trend <0.001). The adjusted odds ratio (OR, 95% confidence interval (CI)) for poor cognitive function in those with the sleep efficiency of 75-85%, 65-75% and <65%, versus ≥85%, was 1.31 (1.12-1.53), 1.41 (1.16-1.73) and 1.33 (1.09-1.63), respectively. No association of the global PSQI score with memory impairment or poor cognitive function was found.

CONCLUSIONS

in older Chinese people, lower habitual sleep efficiency was associated with a higher risk of memory impairment and poorer cognitive function.

The prevalence of obstructive sleep apnea in mild cognitive impairment: a systematic review

Background

Previous studies have shown that obstructive sleep apnea (OSA) is associated with a higher risk of cognitive impairment or dementia in the elderly, leading to deleterious health effects and decreasing quality of life. This systematic review aims to determine the prevalence of OSA in patients with mild cognitive impairment (MCI) and examine whether an association between OSA and MCI exists.

Methods

We searched Medline, PubMed, Embase, Cochrane Central, Cochrane Database of Systematic Reviews, PsychINFO, Scopus, the Web of Science, ClinicalTrials.gov and the International Clinical Trials Registry Platform for published and unpublished studies. We included studies in adults with a diagnosis of MCI that reported on the prevalence of OSA. Two independent reviewers performed the abstract and full-text screening, data extraction and the study quality critical appraisal.

Results

Five studies were included in the systematic review. Overall, OSA prevalence rates in patients with MCI varied between 11 and 71% and were influenced by OSA diagnostic methods and patient recruitment locations (community or clinic based). Among studies using the following OSA diagnostic measures– self-report, Home Sleep Apnea Testing, Berlin Questionnaire and polysomnography– the OSA prevalence rates in MCI were 11, 27, 59 and 71%, respectively. In a community-based sample, the prevalence of OSA in patients with and without MCI was 27 and 26%, respectively.

Conclusions

Based on limited evidence, the prevalence of OSA in patients with MCI is 27% and varies based upon OSA diagnostic methods and patient recruitment locations. Our findings provide an important framework for future studies to prospectively investigate the association between OSA and MCI among larger community-based cohorts and implement a standardized approach to diagnose OSA in memory clinics.

PROSPERO registration

CRD42018096577.

Electronic supplementary material

The online version of this article (10.1186/s12883-019-1422-3) contains supplementary material, which is available to authorized users.

Sleep Quality among Police Officers: Implications and Insights from a Systematic Review and Meta-Analysis of the Literature

Poor sleep is associated with bad health outcomes, worse wellbeing and decreases in performance, productivity and safety at work. Police officers are exposed to several risk factors including extended work schedules, shift work, occupational stress, dangerous and traumatic events and can, as such, develop sleep problems. The aim of the present study was to analyze the sleep quality among police officers. A systematic literature search, in PubMed/MEDLINE, PsycINFO, Scopus, ISI/Web of Science (WoS) and the Cochrane Library was conducted. Original articles, published in English, French, Italian, Spanish and Portuguese, the primary objective of which was the evaluation of the quality of sleep through the Pittsburgh Sleep Quality Index (PSQI) in Police Forces, were selected. From an initial sample of 1,149 studies, 13 articles were included in the meta-analysis (3,722 police officers). The pooled prevalence of bad sleep quality in police officers was 51% [95%CI 42–60%]. The pooled global score of the PSQI was 5.6 [95%CI 5.0–6.3], corresponding to a low average quality. At the meta-regressions, statistically significant associations could be found for work seniority (in terms of years of service) and being on shift. The poor quality of sleep in police officers could have negative consequences for workers’ health and for the safety of third parts. The implementation of health and sleep hygiene promotion programs in police forces is strongly recommended.

Sleep-disordered breathing and Alzheimer's disease: A nationwide cohort study

Sleep-disordered breathing (SDB) is common and can lead to significant cognitive decline, such as Alzheimer's disease (AD). Therefore, the present study was conducted to investigate whether SDB is associated with AD onset. This study used the nationwide health check-up cohort data between 2002 and 2015. The study population comprised individuals who were diagnosed with SDB and those without SDB who were matched by using propensity score. The matched cohort was followed up until the onset of AD, death, or end of 2015. A multivariate Cox proportional hazard model was used in the analysis. There were 727 (16.7%) patients in the SDB group between 2002 and 2005 and 3635 subjects (83.3%) in the propensity score-matched non-SDB group. After adjusting for the possible confounding variables, patients with SDB were almost 1.58 times more likely to develop AD than those without SDB (hazard ratio [HR] = 1.575, 95% confidence interval [CI] = 1.013-2.448). The present study showed that SDB was associated with an onset of AD. The findings of this study highlight the importance of the interventions to raise awareness of SDB and the need for the government's support to reduce the barrier in accessing appropriate SDB treatment.

Sleep Disturbance in Mild Cognitive Impairment and Association With Cognitive Functioning. A Case-Control Study

Objectives: The aims of the current study are to (1) report the frequency of specific sleep disturbance symptoms in Mild Cognitive Impairment (MCI) and cognitive healthy older persons; (2) examine whether overall poor sleep and specific sleep disturbance symptoms are more common in persons with MCI compared to cognitive healthy older controls and; (3) examine the association between sleep disturbances and performance in general and specific cognitive domains in persons with MCI and separately in cognitive healthy older persons.

Methods: Data were collected at the Fondazione Ospedale San Camillo Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Venice, Italy as part of the European VPH-DARE@IT project. We included 69 persons with MCI (mean age 75.7; SD = 7.7) and 72 sex-matched cognitively healthy controls (mean age 71.8; SD = 7.0). Participants underwent extensive neuropsychological assessment and evaluation of subjective sleep performance with the Sleep Continuity in Alzheimer’s Disease Scale(SCADS).

Results: A fifth of MCI patients (21.7%, n = 15) had poor sleep compared to 15.3% (n = 11) of cognitively healthy controls. MCI patients had a 3.2 higher odds of having poor sleep compared to cognitively healthy controls after adjustment for age, education, sex, and general cognitive functioning (Odds Ratio (OR) = 3.2; 95% Confidence Interval (CI) = 1.1–9.2). Persons who reported waking up twice or more during the night had higher odds of being MCI compared to those who never wake or wake only once (OR = 2.6; 95% CI = 1.1–6.1). In MCI patients, poor sleep was associated with better general cognitive functioning and short-term working memory, whereas in cognitive healthy older persons poor sleep was associated with impairment in episodic memory performance and executive functioning.

Discussion: Our results confirm previous studies showing that sleep disturbances are common in MCI, and this may be due to an ongoing neurodegenerative process rather than a symptom of cognitive impairment. Future research with objective sleep measurements are needed in MCI as well as interventions to improve sleep with the aim of preventing cognitive decline.

Sex differences in sleep apnea and comorbid neurodegenerative diseases

Sleep apnea is a disorder, which increasingly affects people worldwide. Whether the associated hypoxic events during sleep are central or obstructive in origin, the end result is excessive daytime sleepiness and an increased risk for several comorbidities, such as cardiovascular and neurodegenerative disorders. Sleep apnea is diagnosed more frequently in men than women, suggesting a role of sex hormones in the pathology of the disease. Furthermore, there are sex differences in the development and progression of comorbid diseases associated with sleep apnea. Therefore, treatment of sleep apnea may be clinically relevant for prevention of subsequent sex-specific comorbid disorders. While the impact sleep apnea has on cardiovascular events has been the subject of many research studies, the role of sleep apnea in neurodegeneration is less established. Here we review known risk factors for sleep apnea and the implications of the observed sex differences in this disease. We also summarize the evidence and mechanisms for how sleep apnea may contribute to the onset of neurodegenerative disorders, such as Alzheimer's disease and Parkinson's disease.

Putative mechanisms of cognitive decline with implications for clinical research and practice

Multiple intrinsic and extrinsic mechanisms contribute to vulnerability of cognitive decline and nurses play a significant role in assisting individuals and families to use strategies for healthy cognitive aging. The objective of this narrative review is to provide a synthesis of the intrinsic and extrinsic mechanisms of cognitive decline and conditions that are associated with cognitive decline. Well-established intrinsic mechanisms of cognitive decline include aging, apolipoprotein E (APOE) ε4 carrier status, SORL1 mutations, neuroinflammation, mitochondrial dysfunction, amyloid deposition, and demyelination. Extrinsic risk factors include obesity, diabetes, hypertension, elevated lipid panel, metabolic syndrome, depression, traumatic brain injury, substance use, heart failure, and stroke. The various definitions of cognitive decline as well as the intrinsic and extrinsic factors that impact cognition as humans age should be incorporated in future clinical research studies. Nurses may use this information to help patients make lifestyle choices regarding cognitive health.

Association of Sleep-Disordered Breathing With Cognitive Function and Risk of Cognitive Impairment: A Systematic Review and Meta-analysis

Importance

Growing evidence suggests an association between sleep-disordered breathing (SDB) and cognitive decline in elderly persons. However, results from population-based studies have been conflicting, possibly owing to different methods to assess SDB or cognitive domains, making it difficult to draw conclusions on this association.

Objective

To provide a quantitative synthesis of population-based studies on the relationship between SDB and risk of cognitive impairment.

Data Sources

PubMed, EMBASE, and PsychINFO were systematically searched to identify peer-reviewed articles published in English before January 2017 that reported on the association between SDB and cognitive function.

Study Selection

We included cross-sectional and prospective studies with at least 200 participants with a mean participant age of 40 years or older.

Data Extraction and Synthesis

Data were extracted independently by 2 investigators. We extracted and pooled adjusted risk ratios from prospective studies and standard mean differences from cross-sectional studies, using random-effect models. This meta-analysis followed the PRISMA guidelines and also adhered to the MOOSE guidelines.

Main Outcomes and Measures

Cognitive outcomes were based on standard tests or diagnosis of cognitive impairment. Sleep-disordered breathing was ascertained by apnea-hypopnea index or clinical diagnosis.

Results

We included 14 studies, 6 of which were prospective, covering a total of 4 288 419 men and women. Pooled analysis of the 6 prospective studies indicated that those with SDB were 26% (risk ratio, 1.26; 95% CI, 1.05-1.50) more likely to develop cognitive impairment, with no evidence of publication bias but significant heterogeneity between studies. After removing 1 study that introduced significant heterogeneity, the pooled risk ratio was 1.35 (95% CI, 1.11-1.65). Pooled analysis of the 7 cross-sectional studies suggested that those with SDB had slightly worse executive function (standard mean difference, -0.05; 95% CI, -0.09 to 0.00), with no evidence of heterogeneity or publication bias. Sleep-disordered breathing was not associated with global cognition or memory.

Conclusions and Relevance

Sleep-disordered breathing is associated with an increased risk of cognitive impairment and a small worsening in executive function. Further studies are required to determine the mechanisms linking these common conditions and whether treatment of SDB might reduce risk of cognitive impairment.

Poor sleep quality is observed in mild cognitive impairment and is largely unrelated to depression and anxiety

BACKGROUND

Individuals with mild cognitive impairment (MCI) commonly experience a number of sleep quality related issues. However, it remains unclear if these issues are specific to MCI or are simply attributed to the elevated levels depression and anxiety symptoms frequently observed among those with MCI. The present study sought to examine group differences between participants with MCI and matched controls on self-reported measures of sleep quality while controlling for depression and anxiety levels.

METHODS

Participants with MCI (N = 48) and demographically matched controls (N = 48) were administered with self-reported measures of anxiety, depression and sleep quality. Sleep quality between both groups were first analyzed using a Multivariate Analysis of Variance, and then subsequently a Multivariate Analysis of Covariance incorporating depression and anxiety scores as covariates.

RESULTS

The MCI group had significantly higher levels of depression and anxiety than the controls. On the sleep-related measures, the MCI group had significantly worse outcomes in sleep duration, disturbances, latency, efficiency, quality and daytime dysfunction. After controlling for depression and anxiety levels, with the exception of daytime dysfunction, all other differences remain significant, and are also associated with moderate to large effect sizes.

CONCLUSION

The results suggest that sleep quality issues are present in MCI and are largely independent of depression and anxiety.

Office-based simple frailty score and central blood pressure predict mild cognitive impairment in an apparently healthy Japanese population: J-SHIPP study

Frailty is associated with cognitive impairment and can be used to identify people at high risk for dementia. We developed a simple frailty (SF) score using a combination of low hand grip strength (<32.5 kg in men, <19.5 kg in women), and short one-leg standing time (<20 seconds). These can be easily measured in the clinician's office when seeing patients. We investigated the possible association between SF score and mild cognitive impairment (MCI) in a cross-sectional study with 838 independent middle-aged to elderly participants (319 men, mean age 65.1years). In total, 118 participants were diagnosed with MCI. A SF score of 2 was significantly associated with the presence of MCI (odds ratio 4.6, 95% confidence interval: 1.9-6.9, p = 0.0001) even after adjustment for age and sex. Stepwise regression analyses showed that a SF score of 2 was associated with the presence of MCI, independently of central pulse pressure and silent cerebral infarcts. These findings indicate that the SF score is a useful frailty parameter to predict MCI in an apparently independent population.

Do Circadian Rhythms Draw the Patterns of Sustained Mental Vigor and Ailment?

Preclinical Research Circadian rhythms are fundamental processes in all cells that coordinate a variety of cellular functions related to a specific time of the day. Disruption of circadian rhythms markedly impacts homeostasis. In this Commentary, we present data that disruption of circadian rhythm may lead to the pathogenesis of neurodegenerative states. In this context, we further argue that there is an urgent need of developing new generations of compounds, chronobiotics, to modulate the molecular substrates of circadian timing system. Chronobiotics conceptually offer an effective way for restoration and protection from the consequences of the circadian disruption. We also briefly discuss whether dysfunctional circadian rhythms are a major driver of aging. Drug Dev Res 77 : 469-473, 2016. © 2016 Wiley Periodicals, Inc.

Circadian Disruption Reveals a Correlation of an Oxidative GSH/GSSG Redox Shift with Learning and Impaired Memory in an Alzheimer's Disease Mouse Model

It is unclear whether pre-symptomatic Alzheimer's disease (AD) causes circadian disruption or whether circadian disruption accelerates AD pathogenesis. In order to examine the sensitivity of learning and memory to circadian disruption, we altered normal lighting phases by an 8 h shortening of the dark period every 3 days (jet lag) in the APPSwDI NOS2-/- model of AD (AD-Tg) at a young age (4-5 months), when memory is not yet affected compared to non-transgenic (non-Tg) mice. Analysis of activity in 12-12 h lighting or constant darkness showed only minor differences between AD-Tg and non-Tg mice. Jet lag greatly reduced activity in both genotypes during the normal dark time. Learning on the Morris water maze was significantly impaired only in the AD-Tg mice exposed to jet lag. However, memory 3 days after training was impaired in both genotypes. Jet lag caused a decrease of glutathione (GSH) levels that tended to be more pronounced in AD-Tg than in non-Tg brains and an associated increase in NADH levels in both genotypes. Lower brain GSH levels after jet lag correlated with poor performance on the maze. These data indicate that the combination of the environmental stress of circadian disruption together with latent stress of the mutant amyloid and NOS2 knockout contributes to cognitive deficits that correlate with lower GSH levels.

Associations between sleep characteristics and weight gain in an older population: results of the Heinz Nixdorf Recall Study

BACKGROUND/OBJECTIVES

Sleep duration influences weight change in children and young adults, but there is less evidence in middle-aged, and, in particular, older adults. We assessed associations between sleep duration, daytime napping and sleep disturbances, respectively, with change of weight and waist circumference in older subjects. Contrary to previous studies, we also used two points in time to assess sleep characteristics.

METHODS

We used data from the population-based Heinz Nixdorf Recall study, a cohort study in Germany with a baseline and two follow-up visits (age 45-74 years, median follow-up 5.1 years for first, 5.2 years for second follow-up visit). In adjusted linear regression models (N=3751), we estimated weight change between baseline and first follow-up visit in relation to various self-reported sleep characteristics measured at baseline. Furthermore, we estimated change of weight and waist circumference, respectively, between first and second follow-up visit in relation to patterns of sleep characteristics measured at baseline and at the first follow-up visit (N=2837).

RESULTS

In all analyses, short and long sleep duration, sleep disturbances, and regular daytime napping were associated with <1 kg of weight gain and <1 cm of gain in waist circumference over 5 years compared with the respective reference categories. For example, compared with 7-<8 h night sleep, short night sleep (⩽5 h at baseline) was associated with 0.5 kg of weight gain (95% confidence interval: -0.1; 1.1 kg).

CONCLUSIONS

Our study gave no evidence that sleep characteristics were associated with clinically relevant weight gain in the older population.

Mild cognitive impairment in a Spanish representative sample: prevalence and associated factors

OBJECTIVE

Given the limitations of treatments for dementia, the characterisation of the early stages of dementia is crucial for the development of preventive programmes and interventions. We aimed to estimate the prevalence of mild cognitive impairment (MCI) and examine its medical and lifestyle correlates in a nationally representative sample of the Spanish population.

METHODS

A total of 3625 participants (≥50 years of age) were interviewed in a cross-sectional study. MCI was defined as the presence of cognitive concerns, the objective evidence of impairment in one or more cognitive domains, the preservation of independence in functional abilities and no dementia. Participants were also asked to provide sociodemographic, health status and lifestyle information. Logistic regression analyses were performed using the overall sample and by age groups.

RESULTS

The overall prevalence of MCI was 9.6%, with higher rates in older people and women. In the overall model, after adjustment for potential confounders, depression [odds ratio (OR) = 1.79; 95% confidence interval (CI) = 1.21, 2.66], diabetes (OR = 1.43; 95% CI = 1.05, 1.95), sleep disturbances (OR = 1.66; 95% CI = 1.09, 2.55) and low level of physical activity (OR = 1.71; 95% CI = 1.26, 2.31) were associated with significantly higher odds for MCI. When stratified by age groups, depression (OR = 2.41; 95% CI = 1.35, 4.31), stroke (OR = 3.77; 95% CI = 1.44, 9.83) and obesity (OR = 2.06; 95% CI = 1.20, 3.53) were significantly associated with MCI in middle-aged participants (50-64 years), whereas low level of physical activity (OR = 1.85; 95% CI = 1.32, 2.59) and sleep disturbances (OR = 1.79; 95% CI = 1.05, 3.05) were associated with MCI in individuals aged 65+ years.

CONCLUSIONS

Significant associations between MCI and psychological, cardiovascular and lifestyle factors were found. Targeting modifiable risk factors might reduce the risk for MCI and subsequent dementia.

Associations among sleep disturbances, nocturnal sleep duration, daytime napping, and incident prediabetes and type 2 diabetes: the Heinz Nixdorf Recall Study

OBJECTIVE

Poor sleep quality as well as short and long sleep duration has been linked to type 2 diabetes. In addition to confirmational analyses, we examined the impact of daytime napping on incident diabetes, and we assessed associations between sleep characteristics and incident prediabetes.

METHODS

In a subgroup of the Heinz Nixdorf Recall Study, a population-based cohort study in Germany (N = 2962; age 45-75 years, without history of cancer, stroke, or cardiovascular diseases), diabetes at baseline and at 5-year follow-up was assessed by self-report and measurement of serum glucose levels. Prediabetes was defined as impaired fasting glucose (6.1-6.9 mmol/L). A sleep questionnaire was used to assess difficulties falling asleep, difficulties maintaining sleep, early morning arousal, and duration of nocturnal and daytime sleep.

RESULTS

In adjusted regression models, short (≤5 hours) and long (≥7.5 hours) sleepers were at greater risk for diabetes (relative risk [RR] = 1.56, 95% confidence interval [CI] = 1.02-2.39, and 1.40, 95% CI = 1.01-1.96, respectively [reference: 7 hours]). Moreover, the prevalence of any regular sleep disorder was associated with incident diabetes (RR = 1.30, 95% CI = 1.01-1.68), and with incident prediabetes (RR = 1.31, 95% CI = 1.00-1.72). Regular daytime nappers had no increased risk of incident diabetes (RR = 1.00, 95% CI = 0.70-1.41).

CONCLUSION

This study shows that people with regular sleep disorders, people with short and long sleep duration, but not regular daytime nappers are at increased risk of diabetes. Furthermore, regular sleep disorders are associated with an increased risk of prediabetes.

Sleep Disturbances in the Elderly

Sleep disturbances are a common presenting symptom of older-age adults to their physicians. This article explores normal changes in sleep pattern with aging and primary sleep disorders in the elderly. Behavioral factors and primary psychiatric disorders affecting sleep in this population are reviewed. Further discussion examines sleep changes associated with 2 common forms of neurocognitive disorder: Alzheimer disease and Lewy Body Dementia. Common medical illnesses in the elderly are discussed in relation to sleep symptoms. Nonpharmacological and pharmacologic treatment strategies are summarized, with emphasis placed on risk of side effects in older adults. Future targets are considered.

Depressive Symptoms are the Main Predictor for Subjective Sleep Quality in Patients with Mild Cognitive Impairment--A Controlled Study

Objective

Controlled data on predictors of subjective sleep quality in patients with memory complaints are sparse. To improve the amount of comprehensive data on this topic, we assessed factors associated with subjective sleep quality in patients from our memory clinic and healthy individuals.

Methods

Between February 2012 and August 2014 patients with mild cognitive impairment (MCI) and subjective cognitive decline (SCD) from our memory clinic and healthy controls were recruited. Apart from a detailed neuropsychological assessment, the subjective sleep quality, daytime sleepiness and depressive symptoms were assessed using the Pittsburgh Sleep Quality Index (PSQI), the Epworth Sleepiness Scale (ESS) and the Beck Depression Inventory (BDI-II).

Results

One hundred fifty eight consecutive patients (132 (84%) MCI patients and 26 (16%) SCD patients) and 75 healthy controls were included in the study. Pairwise comparison of PSQI scores showed that non-amnestic MCI (naMCI) patients (5.4±3.5) had significantly higher PSQI scores than controls (4.3±2.8, p = .003) Pairwise comparison of PSQI subscores showed that naMCI patients (1.1±0.4) had significantly more “sleep disturbances” than controls (0.9±0.5, p=.003). Amnestic MCI (aMCI) (0.8±1.2, p = .006) and naMCI patients (0.7±1.2, p = .002) used “sleep medication” significantly more often than controls (0.1±0.6) Both, aMCI (11.5±8.6, p<.001) and naMCI (11.5±8.6, p<.001) patients showed significantly higher BDI-II scores than healthy controls (6.1±5.3). Linear regression analysis showed that the subjective sleep quality was predicted by depressive symptoms in aMCI (p<.0001) and naMCI (p<.0001) patients as well as controls (p<.0001). This means, that more depressive symptoms worsened subjective sleep quality. In aMCI patients we also found a significant interaction between depressive symptoms and global cognitive function (p = .002)

Discussion

Depressive symptoms were the main predictor of subjective sleep quality in MCI patients and controls, but not in SCD patients. Better global cognitive function ameliorated the negative effect of depressive symptoms on the subjective sleep quality in aMCI patients.