Depressive symptoms moderate the relationship between sleep quality and cognitive functions among the elderly

Investigating a clinically informed sleep disturbance threshold for physical and mental health among Gulf War Illness veterans

Study Objectives

This study (1) assessed sleep quality and health in Gulf War veterans (GWV) meeting the Gulf War Illness (GWI) criteria and (2) compared health associations for both those meeting a "clinically disturbed sleep" threshold, and those below, as determined by the Pittsburgh Sleep Quality Index (PSQI) cutoff for military populations (≥10) on measures of physical, mental, and cognitive health.

Methods

Participant data consisted of questionnaires and assessments completed prior to group assignment in a clinical trial. The sample consisted of 147 GWV, where 81.0% were males, and the median age was 53.4 years.

Results

The mean (SD) PSQI global score was 12.34 (4.00) with 61% of the sample qualifying as clinically disturbed sleepers according to the cutoff (global PSQI ≥ 10). GWI veterans with PSQI scores ≥10 did not differ from others in age (p = 0.20), sex (p = 0.19), or years of education (p = 0.87), but showed worse GW-related symptomology on the Gulf War Kansas questionnaire (p < 0.01), and poorer mental health on the Veterans Rand-36 (p < 0.01).

Conclusions

Disturbed sleep was associated with measures of pain, fatigue, and cognitive health. Our results suggest that a previously determined clinical threshold for clinically disturbed sleep is useful when examining the health status of the study population. Given that GWI is associated with elevated PSQI scores and a high frequency of disturbed sleep, cutoffs determining sleep health should be sensitive to population exposures and health history to improve interpretability.

Exploring the Reciprocal Relationship between Depressive Symptoms and Cognitive Function among Chinese Older Adults

(1) Objectives: This study aims to investigate the bidirectional relationship between depressive symptoms and cognitive function among older adults in China, addressing a research gap in the context of developing nations. (2) Methods: A total of 3813 adults aged 60 and older participating in 2013, 2015, and 2018 waves of the China Health and Retirement Longitudinal Study (CHARLS) were included. A fixed-effects model and cross-lagged panel model (CLPM) was utilized. (3) Results: First, the results indicated that a significant negative correlation existed between depressive symptoms and cognitive function in older adults during the study period (β = -0.084, p < 0.001). Second, after controlling for unobserved confounding factors, the deterioration and improvement of depressive symptoms still significantly affected cognitive function (β = -0.055, p < 0.001). Third, using the cross-lagged panel model, we observed a reciprocal relationship between depressive symptoms (Dep) and cognitive function (Cog) among Chinese older adults (Dep2013 → Cog2015, β = -0.025, p < 0.01; Dep2015 → Cog2018, β = -0.028, p < 0.001; Cog2013 → Dep2015, β = -0.079, p < 0.01; Cog2015 → Dep2018, β = -0.085, p < 0.01). (4) Discussion: The reciprocal relationship between depressive symptoms and cognitive functioning in older adults emphasizes the need for integrated public health policies and clinical interventions, to develop comprehensive intervention strategies that simultaneously address depressive symptoms and cognitive decline.

Executive function and episodic memory composite scores in older adults: relations with sex, mood, and subjective sleep quality

Executive function and episodic memory processes are particularly vulnerable to aging. We sought to learn the degree to which sex, mood, and subjective sleep quality might be related to executive function and episodic memory composite scores in community-dwelling older adults. We replicated Glisky and colleagues' two-factor (i.e., executive function [N=263] versus episodic memory [N=151]) structure, and found that it did not significantly differ between males and females. Moderation analyses revealed no interactions between sex, mood, and sleep in predicting either composite score. However, females significantly outperformed males on the episodic memory composite, and on all the individual tests comprising it. Ours is the first study to look at sex differences in this battery's factor structure and its potential relations with mood and sleep. Future longitudinal studies in both healthy and clinical populations will help us further probe the possible influence of these variables on executive function and episodic memory in aging.

Correlation between sleep characteristics and cognitive decline in the elderly people: A cross-sectional study in China

STUDY OBJECTIVES

In this study, we conducted a cross-sectional analysis of the sleep characteristics in the elderly Chinese people to comprehensively investigate the association between sleep and cognitive function in the elderly people. We aimed to evaluate the most important demographic factors, conventional physiological indices and living habits that may influence sleep.

METHODS

We surveyed 2901 elderly people (age ≥60 years old) face-to-face from 1 July to 31 December 2017, who were recruited from 17 communities of the Pudong New Area (Shanghai, China) by probability proportional to size. The Pittsburgh sleep quality index (PSQI) scale was used to describe the sleep features of each participant. Cognitive assessment was performed using the mini-mental state examination (MMSE) scale, Montreal cognitive assessment (MoCA) and the clinical dementia rating (CDR) scale. Those factors which potentially influence sleep and consequentially may impact cognition in the elderly people were evaluated, and the correlations of sleep characteristics and cognitive function were explored by the linear regression analysis.

RESULTS

Altogether, there were 1287 (44.4%) people taking part in the investigation. Sleep quality was significantly correlated with MMSE and MoCA total scores. Healthy sleep (especially enough sleep) was correlated with better cognitive functions. Besides recognised relative factors (such as age, sex and living alone), the number of children was found to be a strong risk factor of poor sleep. Anxiety before sleep and light/noise interference significantly damaged sleep while an exercise routine was associated with better sleep. Moderate levels of reading, watching TV and household work were correlated with superior sleep quality.

CONCLUSION

In conclusion, sleep characteristics correlate with cognitive decline in the elderly people, and they can be influenced by multiple demographic factors and living habits. To improve sleep quality, it may be important to change sleep environment, to be relax, to increase physical exercise and recreational activities moderately.

Depressive symptom as a mediator of the influence of self-reported sleep quality on falls: a mediation analysis

Objectives: It is well known that sleep quality was associated with falls. This study aimed to examine whether the presence of depressive symptoms mediate the association of self-reported sleep quality with falls.Methods: Data of community-based study including 4,579 adults aged 60 years or older were analyzed. Information regarding sleep quality and falls was self-reported by participants using pre-designed questionnaires. The nine-item Patient Health Questionnaire (PHQ-9) without the sleep item was used to assess the presence of depressive symptoms. A bootstrapping approach was performed to explore whether the relationship between self-reported sleep quality and falls was partially mediated by depressive symptoms. The mediator was considered significant if the 95% confidence interval (CI) did not include 0.Results: Older adults with poor sleep quality had higher odds of falls than their counterparts with normal sleep. In the equation regressed falls on self-reported sleep quality and PHQ-9 score, the association between self-reported sleep quality and falls disappeared. Depressive symptoms partially mediated the association between self-reported sleep quality and falls based on the significance of indirect effect (β = 0.15, 95% bootstrap CI = 0.08, 0.22).Conclusions: The presence of depressive symptoms might partially mediate the association of self-reported sleep quality with falls among older adults.

Predictive factors of cognitive impairment in people over 60

OBJECTIVE

To determine the relationship of depressive symptoms, sleep hygiene, nutritional status and gait speed with cognitive impairment in people over 60 years.

METHOD

Cross-sectional, correlational design with a non-probability convenience sampling. The population was made up of people over 60 years of age belonging to recreational stays in an urban area of Tamaulipas, Mexico. Criterion measures included three neuropsychological tests (Stroop Test, Trail Making Test and Digit Span Subtest) the Geriatric Depression Scale, Pittsburgh Sleep Quality Index, Mini Nutritional Assessment and the Short Physical Performance Battery.

RESULTS

The final sample was of 108 participants. Regarding the influence of risk factors to predict cognitive impairment a significant model was observed (F=12.914, gl=4, P≥.001), showing a variance explained of 33.4%, where depressive symptoms (β=.205, P=.048), sleep (β=-.322, P=.001), nutritional status (β=-.336, P=.001) and gait speed (β=.244, P=.004) were associated with cognitive impairment.

CONCLUSIONS

High levels of depressive symptoms, prolonged sleep duration, a malnutrition status and a slow gait speed predict cognitive impairment of the people over 60 years, this provides knowledge for the implementation of interventions aimed at preventing the risk factors that predict cognitive decline in order to delay its appearance.

Prospective association between sleep-related factors and the trajectories of cognitive performance in the elderly Chinese population across a 5-year period cohort study

The integral role of sleep in cognition, such as night-time sleep and napping duration, has yielded mixed findings, especially in healthy elderly adults. This study aimed to identify the heterogeneous classes of the cognitive trajectories and investigated the associations between sleep parameters and the trajectories of cognition in different elderly subpopulations. The study was based on a large, national representative sample aged 60 years or older. Two cognitive measures were assessed, including executive function and episodic memory. Sleep parameters were evaluated, including post-lunch napping, night-time sleep duration, and sleep disturbances. Latent growth mixture model (LGMM) was used to describe the trajectories of cognition and investigate the effects of sleep factors on cognition. Three heterogeneous trajectories were identified for executive cognition and four for episodic memory. Inverted U-shape associations of cognition with night-time sleep and napping duration were found. In LGMM, night-time sleep duration was negatively associated with the baseline episodic memory in elderly adults. Post-lunch napping was positively associated with the baseline executive function (β = 0.078, P<0.05) and episodic memory (β = 0.084, P<0.05) in men, whereas it was only associated with impaired episodic memory (β = -0.152, P<0.05) in women. Frequent sleep disturbances were only associated with the impaired executive function at baseline (β = -0.088, 95%CI -0.162, -0.013) among older men. Overall, sleep parameters played different roles in heterogeneous trajectories of cognition by sex difference. Sleep factors may not be related to the rate of cognition decline, but these factors, independent of time-variant depressive symptoms, were associated with the initial status of cognition at baseline.