Dataset on the associations between sleep quality/duration and cognitive performance in cognitively healthy older adults

Sleep problems as predictors of cognitive decline in essential tremor: A prospective longitudinal cohort study

BACKGROUND

There is growing evidence that essential tremor (ET) patients are at high risk of cognitive impairment. Predictors of cognitive impairment have not been studied extensively. There is evidence from cross-sectional studies that sleep dysregulation is associated with cognitive dysfunction in ET, but longitudinal studies of the impact of sleep disruption on cognitive change have not been conducted. We investigated the extent to which sleep problems predict cognitive change in patients with ET.

METHODS

ET cases enrolled in a prospective, longitudinal study of cognitive performance. Sleep quality was assessed using the Pittsburg Sleep Quality Index (PSQI). Cognitive abilities across five domains (memory, executive function, attention, language, and visuospatial ability), and a global cognitive score (mean of the domains) were extracted from an extensive neuropsychological assessment. Generalized estimated equations were used to examine the association between baseline sleep problems and cognitive changes over three follow-up assessments each spaced 18 months apart.

RESULTS

The 188 non-demented ET cases had a mean age of 77.7 ± 9.5 years. Longer sleep latency was associated with longitudinal decline in executive function (p = 0.038), and marginally with longitudinal decline in global cognitive performance (p = 0.075). After excluding 29 cases with mild cognitive impairment, results were similar.

CONCLUSION

Cognitively healthy people with ET who have longer sleep latency had greater declines in executive function during prospective follow-up. Early detection of, and possibly intervention for, abnormal sleep latency may protect against certain aspects of cognitive decline in ET patients.

Neurocognitive Characteristics of Subjective Cognitive Decline and Its Association with Objective Cognition, Negative Emotion, and Sleep Quality in Chinese Elderly

Background and Purpose

Subjective cognitive decline (SCD) is recognized as a preclinical indicator of Alzheimer's disease (AD), and this stage provides a valuable time window for ultra-early intervention in AD. The aim of this study was to investigate the neurocognitive characteristics of SCD and its correlation with objective cognition, negative emotion and sleep quality in Chinese elderly.

Methods

A total of 1200 volunteers aged 60 and older underwent Brief Elderly Cognitive Screening Inventory, Quick Cognitive Screening Scale for the Elderly, Generalized Anxiety Disorder-7, Patient Health Questionnaire-9, Pittsburgh Sleep Quality Index and Core Neuropsychological Test. According to the examination results, the participants were divided into healthy control (HC) and SCD groups. The neurocognitive function of SCD and its relationship with objective cognition, negative emotion and sleep quality were analyzed.

Results

Compared with the HC group, the SCD group had similar global cognitive function but slightly impaired neurocognitive function. After adjusting for confounding factors such as age, sex, marriage, education and chronic disease, neurocognitive function (Picture-Symbol Matching: OR=0.167, 95% CI: 0.105-0.266; Word Stem Completion: OR =0.260, 95% CI: 0.131-0.514; Trail Making Test: OR=0.315, 95% CI: 0.178-0.560; Picture Recall: OR =0.278, 95% CI: 0.122-0.636), negative emotion (sub-depressive symptoms: OR=2.287, 95% CI: 1.483-3.527; sub-anxiety symptoms: OR=1.663, 95% CI: 1.079-2.563), and poor sleep quality (OR=2.138, 95% CI: 1.571-2.909) were significantly correlated with the occurrence of SCD.

Conclusion

The study illustrates that SCD is closely related to objective cognition, negative emotion and sleep quality. Clinical evaluation and follow-up of SCD should fully account for these factors.

The Relationship of Neuroticism with Sleep Quality: The Mediating Role of Emotional, Cognitive and Metacognitive Factors

BACKGROUND

Poor sleep quality is associated with a broad range of psychopathology and is a common problem among college students. This study aimed to investigate the mediating role of metacognitive beliefs related to sleep, emotion regulation and a negative cognitive style related to anxiety (looming cognitive style) in the relation between neuroticism and reported sleep quality.

PARTICIPANTS

Participants were 343 undergraduates from three universities in Tehran (56.3% females, Mean age = 22.01 ± 2.74 years).

METHOD

Data were gathered with a questionnaire packet that included the Pittsburgh Sleep Quality Index (PSQI), Metacognitions Questionnaire-Insomnia (MCQ-I), Emotion Regulation Questionnaire (ERQ), Looming Maladaptive Style Questionnaire (LMSQ) and Neuroticism subscale of NEO-PI-R.

RESULTS

Structural equation modeling analyses supported a proposed model (R² = 37%) which proposed that neuroticism both directly and indirectly linked to reported sleep quality through metacognitions related to sleep, cognitive reappraisal and looming cognitive style (χ2 = 1194.87, p < .001; CFI = 0.93, NFI = 0.90, RMSEA = 0.065, GFI = 0.92, SRMR = 0.069, IFI = 0.93).

CONCLUSIONS

The results provide evidence for the impact of neuroticism on reported sleep quality through metacognitive, cognitive and emotional factors. The result suggest that special attention should be paid to these factors in the treatment and psychopathology of sleep quality.

Sleep Polygenic Risk Score Is Associated with Cognitive Changes over Time

Sleep problems have been associated with cognition, both cross-sectionally and longitudinally. Specific genes have been also associated with both sleep regulation and cognition. In a large group of older non-demented adults, we aimed to (a) validate the association between Sleep Polygenic Risk Score (Sleep PRS) and self-reported sleep duration, and (b) examine the association between Sleep PRS and cognitive changes in a three-year follow-up. Participants were drawn from the Hellenic Longitudinal Investigation of Aging and Diet (HELIAD). A structured, in-person interview, consisting of a medical history report and physical examination, was conducted for each participant during each of the visits (baseline and first follow-up). In total, 1376 participants were included, having all demographic, genetic, and cognitive data, out of which, 688 had at least one follow-up visit. In addition, an extensive neuropsychological assessment examining five cognitive domains (memory, visuo-spatial ability, attention/speed of processing, executive function, and language) was administered. A PRS for sleep duration was created based on previously published, genome-wide association study meta-analysis results. In order to assess the relationship between the Sleep PRS and the rate of cognitive change, we used generalized estimating equations analyses. Age, sex, education, ApolipoproteinE-ε4 genotype status, and specific principal components were used as covariates. On a further analysis, sleep medication was used as a further covariate. Results validated the association between Sleep PRS and self-reported sleep duration (B = 1.173, E-6, p = 0.001). Further, in the longitudinal analyses, significant associations were indicated between increased Sleep PRS and decreased visuo-spatial ability trajectories, in both the unadjusted (B = -1305.220, p = 0.018) and the adjusted for the covariates model (B = -1273.59, p = 0.031). Similarly, after adding sleep medication as a covariate (B = -1372.46, p = 0.019), none of the associations between Sleep PRS and the remaining cognitive domains were significant. PRS indicating longer sleep duration was associated with differential rates of cognitive decline over time in a group of non-demented older adults. Common genetic variants may influence the association between sleep duration and healthy aging/cognitive health.

Noon is the best time to perform a dual task while cognitive performance may be boosted by concurrent performance of a physical task

BACKGROUND

Dual-task is the concurrent performance of two independent single tasks (ST) that have distinct goals. Daily variations in performance of singular cognitive or motor tasks are reported in the literature.

RESEARCH QUESTION

To investigate whether performance of a dual-task (DT) varies based on the time of day and whether there is interference between the motor and cognitive aspect of DT.

METHODS

Participants performed a 10 Meter Walk Test (10MWT) for motor and a Stroop Test for cognitive task. The DT activity combined both STs. All participants performed three trials for all three conditions at three different times of the day (morning, noon, afternoon), on separate testing days.

RESULTS

Data were collected on 42 participants. Most participants were female (28/42), average age of 27.95 ± 9.28 years, and BMI of 25.58 ± 4.49 Kg/m2. Walking velocities in ST were consistently faster than in DT, p < .0005. In DT conditions, the participants walked faster at noon (1.21 ± 0.13 m/s) compared to the morning (1.16 ± 0.15 m/s, p = 0.01) or the afternoon (1.16 ± 0.18 m/s, p = 0.04). The participants' score on the DT-Stroop test were only different at noon (11.43 ± 2.28) when compared to morning (10.67 ± 1.34, p = 0.006). The percentage DT-Cognitive interference effect was 26.1 % in the morning, 11.8 % at noon and 13.4 % in the afternoon. The Motor interference was -14.6 % in the morning, -12.2 % at noon and -13.8 % in the afternoon.

SIGNIFICANCE

Noon is the best time to perform a dual task condition. Noon consistently exhibited the least motor or cognitive interference. Conversely, the maximum boost in cognitive performance was observed in the mornings.

Assessing functional status using the IADL-extended scale: results from the HELIAD study

OBJECTIVES

Instrumental activities of daily living (IADL) have been operationalized as exhibiting a greater level of complexity than basic ADL. In the same way, incorporating more advanced ADLs may increase the sensitivity of functional measures to identify cognitive changes that may precede IADL impairment. Towards this direction, the IADL-extended scale (IADL-x) consists of four IADL tasks and five advanced ADLs (leisure time activities).

DESIGN

Retrospective, cross-sectional study.

SETTING

Athens and Larissa, Greece.

PARTICIPANTS

1,864 community-dwelling men and women aged over 64.

MEASUREMENTS

We employed both the IADL-x and IADL scales to assess functional status among all the participants. Diagnoses were assigned dividing the population of our study into three groups: cognitively normal (CN), mild cognitive impairment (MCI) and dementia patients. Neuropsychological evaluation was stratified in five cognitive domains: memory, language, attention-speed, executive functioning and visuospatial perception. Z scores for each cognitive domain as well as a composite z score were constructed. Models were controlled for age, sex, education and depression.

RESULTS

In both IADL-x and IADL scales dementia patients reported the most functional difficulties and CN participants the fewest, with MCI placed in between. When we restricted the analyses to the CN population, lower IADL-x score was associated with worse cognitive performance. This association was not observed when using the original IADL scale.

CONCLUSION

There is strong evidence that the endorsement of more advanced IADLs in functional scales may be useful in detecting cognitive differences within the normal spectrum.

Pre-experimental sleep effects on directed forgetting

A directed forgetting (DF) paradigm was used to compare the remembering and forgetting of participants with good sleep quality to those with poor sleep quality and the presence of insomnia symptoms. This study implemented a point system in place of remember and forget instructions in a DF task with the goal of computing DF costs and benefits. Relations among memory, sleep, and working memory capacity (WMC) were also examined. DF benefits were observed in both groups, with negative costs found for participants without the presence of insomnia symptoms. WMC was found to be related to memory for positive point items only, and did not differ based on sleep quality. These results suggest that the presence of self-reported insomnia symptoms does not affect performance on a DF task.

Pesticide exposure and cognitive function: Results from the Hellenic Longitudinal Investigation of Aging and Diet (HELIAD)

BACKGROUND

Results from studies to date, regarding the role of chronic pesticide exposure on cognitive function remain contradictory.

OBJECTIVE

To investigate the relationship between self-reported pesticide exposure and cognitive function.

METHODS

Data from a population-based cohort study of older adults (HEllenic Longitudinal Investigation of Aging and Diet) in Greece was used. Pesticide exposure classification was based on 1) living in areas that were being sprayed; 2) application of spray insecticides/pesticides in their gardens; and 3) occupational application of sprays. Associations between z-scores of cognitive performance and self-reported pesticide exposure were examined with linear regression analyses. Adjusted models were applied, for all analyses.

RESULTS

Non-demented individuals who reported that they had been living in areas near sprayed fields, had poorer neuropsychological performance, compared to those who had never lived in such areas. Sub-analyses revealed poorer performance in language, executive and visual-spatial functioning, and attention. These associations remained after a sensitivity analysis excluding subjects with mild cognitive impairment.

CONCLUSION

Self-reported exposure to pesticides was negatively associated with cognitive performance.

Sleep quality components and mental health: Study with a non-clinical population

The deconstruction of sleep quality into its particular components may help to specify how each one of them influences mental health. Thus, to detail the understanding of the relationship between sleep quality and mental health, our study aims to assess the relationship between each component of the Pittsburgh Sleep Quality Index (PSQI) and depression, anxiety and stress. Also, we intend to analyse the moderating effects of gender, age and country on these relationships. The instruments PSQI and Depression Anxiety Stress Scale (DASS-21) were applied to a non-clinical population of 1552 participants from three different countries (Portugal, Spain and Brazil), aged over 18 years old. We estimated a multivariate regression model with AMOS Graphic 21.0 to test the seven proposed research hypotheses. The adjusted model explains 14.0%, 21.0% and 19.3% of the variances of depression, anxiety and stress, respectively. The conclusion of this study demonstrates that, with the exception of subjective sleep quality, all the other six components of the PSQI individually relate to mental health in non-clinical populations and that country is a significant moderator of these relationships.

Beneficial Effect of Multidomain Cognitive Training on the Neuropsychological Performance of Patients with Early-Stage Alzheimer's Disease

Background and Purpose

There is an increasing interest in the effect of nonpharmacological interventions on the course of patients with Alzheimer's disease (AD). The objective of the present study is to determine the benefits of a structured, multidomain, mostly computer-based, cognitive training (MCT) οn the cognitive performance of patients with early-stage AD.

Method

Fifty patients with early-stage AD participated in the study. Patients were randomly allocated either to the training program group (n = 25) or to a wait list control group (n = 25). The training program group received computer-assisted MCT and linguistic exercises utilizing pen and paper supplemented by cognitive-linguistic exercises for homework. The duration of the MCT intervention program was 15 weeks, and it was administered twice a week. Each session lasted for approximately one hour. Objective measures of episodic memory, delayed memory, word recognition, attention, executive function, processing speed, semantic fluency, and naming were assessed at baseline and after the completion of the program in both groups.

Results

Analysis showed that in controls, delayed memory and executive function had deteriorated over the observation period of 15 weeks, while the training group improved their performance in word recognition, Boston Naming Test (BNT), semantic fluency (SF), clock-drawing test (CDT), digit span forward (DSF), digit span backward (DSB), trail-making test A (TMT A), and trail-making test B (TMT B). Comparison between the training group and the controls showed that MCT had a significant beneficial effect in delayed memory, naming, semantic fluency, visuospatial ability, executive functions, attention, and processing speed.

Conclusions

The study provides evidence of a beneficial effect of MCT with an emphasis on cognitive-language performance of patients with early-stage AD. Considering the limited efficacy of current pharmacological therapies in AD, concurrent computer-based MCT may represent an additional enhancing treatment option in early-stage AD patients.