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

Worldwide prevalence of sleep problems in community-dwelling older adults: A systematic review and meta-analysis

The understanding of the prevalence of sleep problems in older adults can provide a broad and reliable perspective into the occurrence of such issues among older adults. This systematic review and meta-analysis aimed to estimate the worldwide prevalence of sleep problems in community-dwelling older adults. Studies that provide information on the prevalence of sleep problems in community-dwelling older adults (≥60 years) were screened between December 2022 and March 2023. A total of 20,379 studies were identified in database searches, from which 252 were included in this review. These studies covered the last 35 years (from 1988 to 2023) and pooled a sample of 995,544 participants from 36 countries. The most frequent sleep problem worldwide was obstructive sleep apnea (46.0%), followed by poor sleep quality (40.0%), other sleep problems (37.0%), insomnia (29.0%), and excessive daytime sleepiness (19.0%). No significant difference in the prevalence estimates of all sleep problems was observed between the sexes. This systematic review and meta-analysis showed a high prevalence of some sleep problems, mainly obstructive sleep apnea, poor sleep quality, and other sleep problems. Our estimates can be useful for managers and policymakers in planning healthcare strategies for sleep problems aimed at the older population.

Sleep and Depression in Older Adults: A Narrative Review

PURPOSE OF REVIEW

The sleep-depression association has been recognized for decades. Efforts to clarify this association continue at an increasing pace. This review summarizes recent research on the sleep-depression association in older adults.

RECENT FINDINGS

Research over the past 4 years has utilized cross-sectional, longitudinal, cohort, and intervention designs to examine these associations. Short (< 7 h) and long (> 8-9 h) sleep durations and insomnia symptoms are risk factors for depression in older adults. Similarly, short sleep, long sleep, insomnia symptoms, and depression are all risk factors for poorer health in late life, including increased risk of cognitive decline, falls, and poorer quality-of-life. Intervention studies have produced mixed findings, with some studies suggesting that sleep interventions may be potentially effective in improving both insomnia and mood symptoms. Intervention studies incorporating both behavioral and physiological measures of sleep, and larger and diverse samples may enhance the field's understanding of the complex interplay between sleep and mood in older adults.

Selenium attenuates the association of co-exposure to arsenic, cadmium, and lead with cognitive function among Chinese community-dwelling older adults

The effects of interactions between the toxic and essential metal mixtures on cognitive function are poorly understood. This study aims to identify the joint association of arsenic (As), cadmium (Cd), and lead (Pb) with cognitive function in older adults and the moderating role of selenium (Se), zinc (Zn), and copper (Cu) in this association. This study included 1000 community-dwelling older adults. Cognitive function was assessed by the Mini-Mental State Examination (MMSE). Blood concentrations of As, Cd, Pb, Se, Zn, and Cu were measured using inductively coupled plasma mass spectrometry. Linear regression and Bayesian kernel machine regression (BKMR) models were applied to assess the individual and joint associations of As, Cd, and Pb with cognitive function and to examine whether Se, Zn, and Cu (individually and as a mixture) modified these associations. In the adjusted single-metal models, both Cd (β = - 0.37, 95% CI: - 0.73 to - 0.01) and Pb (β = - 0.44, 95% CI: - 0.86 to - 0.02) were associated with MMSE scores, while Se (β = 0.71, 95% CI: 0.30 to 1.13) exhibited a positive relationship with MMSE scores. Univariate exposure-response functions from BKMR models showed similar results. Moreover, the toxic metal mixture (As, Cd, and Pb) exhibited a significant negative association with MMSE scores in a dose-response pattern, with Pb being the greatest contributor within the mixture. The negative association of Pb alone or the toxic metal mixture with MMSE scores became weaker at higher concentrations of Se within its normal range, especially when Se levels were greater than the median (89.18 μg/L). Our findings support that Se can attenuate the negative associations of exposure to single Pb or the As, Cd, and Pb mixtures with cognitive function. Future prospective studies are needed to replicate our findings.

Trajectories of Sleep Disturbance and Self-Management of Chronic Conditions during COVID-19 among Middle-aged and Older Adults

Background

The COVID-19 pandemic has had a widespread impact on sleep quality, yet little is known about the prevalence of sleep disturbance and its impact on self-management of chronic conditions during the ongoing pandemic.

Objective

To evaluate trajectories of sleep disturbance, and their associations with one's capacity to self-manage chronic conditions.

Design

A longitudinal cohort study linked to 3 active clinical trials and 2 cohort studies with 5 time points of sleep data collection (July 15, 2020 - May 23, 2022).

Participants

Adults living with chronic conditions who completed sleep questionnaires for two or more time points.

Exposure

Trajectories of self-reported sleep disturbance across 5 time points.

Main Outcomes

3 self-reported measures of self-management capacity, including subjective cognitive decline, medication adherence, and self-efficacy for managing chronic disease.

Results

549 adults aged 23 to 91 years were included in the analysis. Two thirds had 3 or more chronic conditions; 42.4% of participants followed a trajectory of moderate or high likelihood of persistent sleep disturbance across the study period. Moderate or high likelihood of sleep disturbance was associated with older age (RR 1.57, 95% CI 1.09, 2.26, P<.05), persistent stress (RR 1.54, 95% CI 1.16, 2.06, P=.003), poorer physical function (RR 1.57, 95% CI 1.17, 2.13, P=.003), greater anxiety (RR 1.40, 95% CI 1.04, 1.87, P=.03) and depression (RR 1.63, 95% CI 1.20, 2.22, P=.002). Moderate or high likelihood of sleep disturbance was also independently associated with subjective cognitive decline, poorer medication adherence, and worse self-efficacy for managing chronic diseases (all P<.001).

Conclusions

Persistent sleep disturbance during the pandemic may be an important risk factor for inadequate chronic disease self-management and potentially poor health outcomes in adults living with chronic conditions. Public health and health system strategies might consider monitoring sleep quality in adults with chronic conditions to optimize health outcomes.

The Influence of Alcohol Consumption, Depressive Symptoms and Sleep Duration on Cognition: Results from the China Health and Retirement Longitudinal Study

AIM

Healthy cognition-related factors include alcohol consumption, depressive symptoms, and sleep duration. However, less is known about the role of these factors in the dyad or tripartite relationships. In this study, we examined whether there were potential mediation effects, moderation effects, and interactions between these factors in the longitudinal study.

METHODS

Both cross-sectional data analysis and a longitudinal study were performed using baseline and 2018 data from the China Health and Retirement Longitudinal Study (CHARLS) cohort. CHARLS is a nationwide survey program covering 450 villages and 150 counties in 28 provinces that aims to investigate comprehensive demographic information. After selecting participants from the CHARLS cohort, 15,414 were included in the study. Non-drinkers, those who drink more than once a month, and those who drink less than once a month were defined by their alcohol consumption. Depressive symptoms were defined as nondepressed (less than or equal to 12) and depressed (more than 12). Sleep duration was defined as 7-8 h per night, ≤6 h per night, and ≥9 h per night. The total cognitive scores were calculated from memory, orientation, and executive tests. The PROCESS macro in SPSS was used to analyze all mediations and moderating mediations.

RESULTS

Alcohol consumption has a positive correlation with cognition. The global cognition z scores of participants with depressive symptoms were significantly lower than those of the control (all p's < 0.001), in different models. The memory score (β: -0.148; 95% CI: -0.240 to -0.056; p = 0.002), the executive score (β: -0.082; 95% CI: -0.157 to -0.006; p = 0.033), and the global cognition score (β: -0.105; 95% CI: -0.187 to -0.023; p = 0.012) of participants defined as ≤6 h per night were, obviously, less than the control (7-8 h per night). An association between depression and alcohol consumption has been found, and the protective effects have been reversed by depression, which caused the cognition decline. Sleep duration was identified as a moderator, influencing the relationship between depressive symptoms and cognitive function. Besides, there was an interaction causing cognition decline among alcohol consumption, depressive symptoms, and sleep duration. Cognitive function showed a marked downward trend with increasing age.

CONCLUSIONS

In this model, depression primarily mediates the relationship between alcohol consumption and cognition, and sleep duration changes the mediation effect. Furthermore, there is a significant interaction between alcohol consumption, depressive symptoms, and sleep duration, which are significantly associated with cognitive function.

Mechanisms connecting insomnia to hopelessness among Chinese older adults: Serial mediating roles of fatigue and social support

BACKGROUND

Hopelessness and insomnia remain growing mental health issues worldwide, their relationship has been neglected by international development policies, especially in the countries with rapidly aging population like China. However, there is little conclusive evidence on the mechanisms through which insomnia severity influences hopelessness. Based on previous research regarding the significant associations among fatigue, social support, insomnia and hopelessness, this study aims to investigate the relationship between insomnia and hopelessness as well as how insomnia affects hopelessness through fatigue and social support.

METHODS

A population-based data including 946 community-dwelling older adults extracted from "Elderly Care Household Survey in 2019" in Beijing were used. The age of the participants ranged from 66 to 97 years old, and 53.3% of the respondents were female. Intercorrelations among insomnia, fatigue, social support and hopelessness were examined. Serial multiple mediation models were analyzed by the bootstrapping method to assess whether fatigue and social support serially mediate the relationship between insomnia and hopelessness.

RESULTS

Higher level of insomnia severity (coefficient = 0.0421, p < 0.001), higher level of fatigue (coefficient = 0.0171, p < 0.001), and lower level of social support (coefficient = -0.0320, p < 0.001) were significantly associated with higher level of hopelessness. Fatigue and social support in serial, mediated the relationship between insomnia and hopelessness (total effect: coefficient = 0.0623, 95% CI [0.0466, 0.0780]; total direct effect: coefficient = 0.0421, 95% CI [0.0262, 0.0581]; total indirect effect: coefficient = 0.0202, 95% CI [0.0147, 0.0272]).

CONCLUSIONS

Improving sleep quality and eliminating fatigue could effectively alleviate the sense of hopelessness among Chinese older adults. In addition, establishing stronger social support brought by social network from family and friends could confer resilience against the negative effects of despair brought by insomnia. Our findings highlighted the mechanism connecting insomnia to hopelessness, which would inspire the future practice.

Neuropsychiatric Symptoms Exacerbate the Cognitive Impairments in Patients With Late-Life Depression

Background: Neuropsychiatric symptoms (NPS) and cognitive impairments are both common in patients with late-life depression (LLD). However, the relationship between NPS and cognitive functions in LLD patients remains unclear. The current study aims to explore the effects of NPS on cognitive impairments in LLD patients. Methods: Two hundred and sixty-two LLD patients and 141 normal controls (NC) were recruited. Exploratory factor analysis was used to extract factors from the Neuropsychiatric Inventory (NPI). Correlation, mediation, and moderation analyses were used to explore whether NPS exacerbated the cognitive impairments in LLD and whether NPS exhibited different effects on cognitive impairments in acute-state LLD (aLLD) and recovery-state LLD (rLLD). Results: Three main factors were extracted from the NPI, including emotional, behavioral, and psychotic factors. The patients with LLD exhibited worse cognition and higher NPI scores, and the scores of NPI-total and three extracted factors were negatively associated with cognitive scores. The mediation analyses exhibited that NPI-total and behavioral factor scores increase the difference in cognition scores between LLD and NC groups. The mediation analyses exhibited that behavioral factor score played a greater effect on impairing MMSE in the rLLD group than in the aLLD group. Additionally, behavioral factor score was in a trend to be negatively associated with Mini-Mental State Examination (MMSE) score changes at a one-year follow-up (p = 0.051). Conclusions: NPS, especially behavioral symptoms, exacerbate cognitive impairments in LLD and may contribute to residual cognitive impairment in rLLD patients. Early intervention for behavioral symptoms in LLD patients may be beneficial to their long-term clinical prognosis.