Association between daytime napping duration and depression in middle-aged and elderly Chinese: evidence from the China Health and Retirement Longitudinal Study (CHARLS): A cross-sectional study in China

Changes in Sleep Duration and Sleep Timing in the General Population from before to during the First COVID-19 Lockdown: A Systematic Review and Meta-Analysis

BACKGROUND

The COVID-19 lockdown had a profound effect on everyday life, including sleep health. This systematic review and meta-analysis evaluated changes in quantitative sleep parameters during the first lockdown compared with pre-lockdown in the general population.

METHODS

A search in scientific databases was performed to identify eligible observational studies from inception to 8 February 2023. We performed a random effects meta-analysis of those studies reporting (a) means of sleep duration, time in bed (TIB), and sleep timing (bedtime and wake-up time); (b) the percentages of atypical sleep duration before and during the lockdown; (c) the percentages of change in sleep duration and sleep timing.

RESULTS

A total of 154 studies were included. A small increase in sleep duration (0.25 standardized mean difference, 95% CI 0.180-0.315) was found, with 55.0% of the individuals reporting changes, predominantly an increase (35.2%). The pooled relative risk for sleeping more than 8/9 h per night was 3.31 (95% IC 2.60-4.21). There was a moderately significant delay in sleep timing and a surge in napping.

CONCLUSION

An increase in sleep duration and napping, and delayed sleep timing were observed. High-quality studies should evaluate whether these parameters have now become chronic or have returned to pre-lockdown values.

Associations between afternoon napping, left amygdala volume and cognitive performance in elderly with normal cognitive function

BACKGROUND

The relationship between afternoon napping and cognitive function in the elderly is very complex and the mechanism is unknown.

METHODS

In the current study, 194 community elders with normal cognitive functions were included. All subjects completed baseline clinical assessment, baseline neuropsychological test as well as baseline structural MRI. Based on their napping status, these 194 participants were divided into the napping group (n = 88) and the non-napping group (n = 106). We then compared the differences in cognitive performance and structural magnetic resonance between the two groups.

RESULTS

In the intergroup analysis, we found that the nappers showed poorer cognitive performance on both overall cognitive function and domain specific cognitive function; while on the whole sample, we found a significant negative association (F = 20.27, p<0.001) between afternoon napping and left amygdala volume. However, we did not find any effect of night sleep length or napping frequency on cognitive performance or left amygdala volume.

CONCLUSIONS

In community elders with normal cognitive functions, afternoon napping is associated with cognitive performance, and left amygdala may play an important role in this process.

Associations of daytime napping and nighttime sleep quality with depressive symptoms in older Chinese: the Guangzhou biobank cohort study

BACKGROUND

Poor sleep quality has been linked to depression in older adults, but results of the association between daytime napping and depression remains limited and conflicting. Moreover, whether the association of daytime napping with depression varies by nighttime sleep quality is unclear. Hence, we examined the associations of daytime napping and nighttime sleep quality with depressive symptoms in older Chinese.

METHODS

A total of 16,786 participants aged ≥50 from the Guangzhou Biobank Cohort Study second-round examination (2008-2012) were included in this cross-sectional study. Geriatric Depression Scale (GDS-15), Pittsburgh Sleep Quality Index (PSQI), napping and demographic data were collected by face-to-face interview using a computerized questionnaire. Logistic regression was used to calculate odds ratio (OR) of depressive symptoms for napping and sleep quality.

RESULTS

The prevalence of depressive symptoms (GDS score > 5) and poor global sleep quality (PSQI score ≥ 6) was 5.3 and 31.9%, respectively. Compared to non-nappers, nappers showed significantly higher odds of depressive symptoms, with OR (95% confidence interval (CI)) being 1.28 (1.11-1.49). The odds of depressive symptoms for daytime napping varied by nighttime sleep quality (P for interaction = 0.04). In good-quality sleepers, compared to non-nappers, nappers had significantly higher odds of depressive symptoms, with OR (95% CI) being 1.57 (1.23-2.01), whereas no association was found in poor-quality sleepers (OR = 1.13, 0.94-1.36).

CONCLUSION

Napping was associated with higher odds of depressive symptoms in older people, and the association was stronger in good-quality sleepers.

Association between internet use and depressive symptoms among older adults: mediating role of daytime napping and moderating role of productive engagement

OBJECTIVES

This study investigated the mediating role of daytime napping in the relationship between internet use and depressive symptoms among older adults. Further the moderating effect of productive engagement was assessed on the linkage between internet use and depressive symptoms.

METHODS

We surveyed 956 Chinese community-dwelling older adults. Respondents reported their internet use for different purposes (social, informational, and instrumental use), rated their levels of depressive symptoms and of daytime napping, and reported different types of/overall productive engagement. We conducted mediation and moderation analyses to test the potential pathways of associations among those factors.

RESULTS

Daytime napping mediated the association between social and informational internet use and depressive symptoms. Family caregiving, sporting activities, and overall productive engagement each moderated the relationship between internet use and depressive symptoms.

CONCLUSION

Internet use can increase the risk of depressive symptoms in older adults by increasing daytime napping. However, the benefits of internet use can be particularly salient for those who have a low level of productive engagement. The findings have implications for policies and practices that are designed to help older adults access the internet to enhance well-being.

Sleep Behaviors and Progression of Multimorbidity in Middle-Aged and Older Adults: A Prospective Cohort Study From China

BACKGROUND

Sleep behavior (eg, sleep duration, sleep quality, and nap) is closely related to many chronic conditions. However, less is known about its association with multiple chronic conditions (multimorbidity), particularly evidence from cohort studies.

METHODS

Data were collected from a cohort of 8 937 individuals aged 45 and older from the China Health and Retirement Longitudinal Study (2011-2018). Sleep duration, sleep quality, and nap duration were collected in 2011 and 2013. Progression of multimorbidity was defined as the first report of 2 or more chronic conditions for participants without multimorbidity or the new report of 1 or more conditions for those with multimorbidity. Cox regression models were performed to calculate the hazard ratios and 95% confidence intervals (CIs) of the associations between sleep behaviors and the progression of multimorbidity.

RESULTS

Short sleep duration and poor sleep quality were associated with the progression of multimorbidity independently and jointly, especially in those less than 65 years and females. The U-shaped dose-response relationships were observed between nighttime and total sleep duration and the progression of multimorbidity. Persistent short and unsteadily changed sleep behaviors increased the risk of multimorbidity progression. Individuals sleeping ≤5 h/night with 5-7 restless days/week had 1.53 times higher risk of multimorbidity progression (95% CI: 1.37-1.71), compared to those sleeping 7-8 h/night with <1 restless day/week.

CONCLUSIONS

Short sleep duration and poor sleep quality were independently and jointly associated with a higher risk of multimorbidity progression in a mid-to-older population. Optimal sleep duration and sleep quality should be emphasized in multimorbidity prevention and control.

Longitudinal relationship between body mass index and depressive symptoms among Chinese adults: The moderating roles of lifestyle factors and age

OBJECTIVE

This study aims to verify the moderating roles of lifestyle factors and age between body mass index (BMI), BMI trajectory and depressive symptoms of Chinese adults through a prospective design.

METHODS

The participants who are 18 years old and above from the China Family Panel Studies (CFPS) were included in the 2016 baseline and 2018 follow-up research. BMI was calculated according to self-report weight (kilogram) and height (centimeter). Depressive symptoms were evaluated via the Center for Epidemiologic Studies Depression (CESD-20) scale. Inverse probability-of-censoring weighted estimation (IPCW) was used to check whether selection bias existed. Modified Poisson regression was performed to calculate prevalence and risk ratios as well as 95% confidence intervals.

RESULTS

After adjustment, it was found that the positive associations of persistent underweight (RR = 1.154, P < 0.001) and normal weight → underweight (RR = 1.143, P < 0.001) with 2018 depressive symptoms were significant among middle-aged people, while the negative association of persistent overweight/obesity (RR = 0.972, P < 0.001) was significant in young adults. Notably, smoking moderated the relationship between baseline BMI and subsequent depressive symptoms (interaction P = 0.028). Also, exercise regularly and exercise duration weekly moderated the relationships of baseline BMI (interaction P = 0.004 and 0.015) and trajectories of BMI (interaction P = 0.008 and 0.011) with depressive symptoms among Chinese adults, respectively.

CONCLUSION

Weight management strategies for underweight and normal weight → underweight adults should pay attention to the role of exercise in maintaining normal weight and improving depressive symptoms.

Association between air quality satisfaction, family relationships, and depression symptoms among middle-aged and elderly chinese people: the mediation role of perceived health status

BACKGROUND

Population aging has led to depression becoming a serious public health problem both in China and worldwide. Marital relationships, relationships with their children, and air pollution might play an important role in the process of depressive disorders. In this study, we aimed to reveal the mechanism of the effects of these factors on depression.

METHODS

Participants were recruited from The China Health and Retirement Longitudinal Study (CHARLS) (wave 4) from July 2018 to March 2019. Depression symptoms were evaluated using the 10-item Center for Epidemiologic Studies depression scale (CESD-10). Marital relationships, relationships with their children, air quality satisfaction, and perceived health status were analyzed using Likert 5-point evaluation methods. Structural equation modeling-path (SEM) models were used to explore these variables' mediation effects on depression symptoms.

RESULTS

Marital relationships, relationships with their children, air quality satisfaction, perceived health status, and depression symptoms were significantly associated with each other (P < 0.001). Mediation analysis showed that family relationships (standardized beta = -0.28 [-0.31, -0.26]) and quality satisfaction (standardized beta = -0.03 [-0.05, -0.01]) had negative effects on depression symptoms. The total indirect effects of family relationships and air quality satisfaction on depression symptoms were -0.06 (95% confidence interval (CI) = [-0.07, -0.05]) and -0.016 (95% CI = [-0.02, -0.01]), respectively.

CONCLUSION

Family relationships, air quality satisfaction, and perceived health status influenced depression symptoms. The effects of family relationships and air quality satisfaction on depression symptoms were significantly mediated by perceived health status. Therefore, perceived health status aspects should be considered when conducting targeted intervention toward depression symptoms among middle-aged and elderly adults.

Daytime naps and depression risk: A meta-analysis of observational studies

Background

The relationship between daytime napping and depression remains debatable. Thus, a meta-analysis in this study was conducted to evaluate the relationship between daytime napping and depression.

Methods

The PubMed, Embase, Web of Science, and China National Knowledge Infrastructure databases were searched up to February 2022, and the reference lists of the included studies were also retrieved. A random-effects model was used to estimate the combined effect size.

Results

Nine studies with 649,111 participants were included in the final analysis. The pooled odds ratio (OR) was 1.15 (95% confidence interval: 1.01-1.31) with a significant heterogeneity (I ² = 91.3%, P for heterogeneity <0.001), and the results demonstrated an increased risk of depressive symptoms among daytime nappers. Visual inspection of the funnel plot and Egger's and Begg's tests identified no obvious evidence of publication bias.

Conclusion

This meta-analysis indicates that daytime naps are a predictor of depression. The effects of daytime napping on depression may vary depending on the characteristics of people, the pattern of naps, and the individual's sleep experience. The findings may have significant implications for future research on depression.

Development and validation of the Chinese Geriatric Depression Risk calculator (CGD-risk): A screening tool to identify elderly Chinese with depression

BACKGROUND

The prevalence of depression among China's elderly is high, but stigma surrounding mental illness and a shortage of psychiatrists limit widespread screening and diagnosis of geriatric depression. We sought to develop a screening tool using easy-to-obtain and minimally sensitive predictors to identify elderly Chinese with depressive symptoms (depression hereafter) for referral to mental health services and determine the most important factors for effective screening.

METHODS

Using nationally representative survey data, we developed and externally validated the Chinese Geriatric Depression Risk calculator (CGD-Risk). CGD-Risk, a gradient boosting machine learning model, was evaluated based on discrimination (Concordance (C) statistic), calibration, and through a decision curve analysis. We conducted a sensitivity analysis on a cohort of middle-aged Chinese, a sub-group analysis using three data sets, and created predictor importance and partial dependence plots to enhance interpretability.

RESULTS

A total of 5681 elderly Chinese were included in the development data and 12,373 in the external validation data. CGD-Risk showed good discrimination during internal validation (C: 0.81, 95 % CI 0.79 to 0.84) and external validation (C: 0.77, 95 % CI: 0.76, 0.78). Compared to an alternative screening strategy CGD-Risk would correctly identify 17.8 more elderly with depression per 100 people screened.

LIMITATIONS

We were only able to externally validate a partial version of CGD-Risk due to differences between the internal and external validation data.

CONCLUSIONS

CGD-Risk is a clinically viable, minimally sensitive screening tool that could identify elderly Chinese at high risk of depression while circumventing issues of response bias from stigma surrounding emotional openness.

Prevalence and associated factors of cognitive impairment among the elderly population: A nationwide cross-sectional study in China

Background

Cognitive impairments are associated with increased risk for progression to dementia. In China, limited surveys have been conducted to estimate the national prevalence and risk factors associated with cognitive impairment in China. This study aims to assess the national prevalence and modifiable risk factors for cognitive impairments in the Chinese elderly population.

Methods

This cross-sectional study was based on the 2018 China Health and Retirement Longitudinal Study. The Mini Mental State Examination (MMSE) is recommended to test for cognitive impairment. Univariate and multivariate logistic regression models were used in assessing risk factors for cognitive impairments in the Chinese elderly population.

Results

A total of 3768 participants aged 60 years or older were enrolled in this study. The national prevalence of cognitive impairments was 22.24% in China, and the prevalence of cognitive impairment was higher in the south-west region than in the north region (29.94 vs. 16.53%, p < 0.05). The risk for cognitive impairments was higher in the following participants: not married or not living with spouse relative to married with spouse present (OR = 1.39, 95% CI, 1.15-1.70; p = 0.001), nap duration of ≥ 90 min relative to 30-60 min (OR = 1.54, 95% CI, 1.20-1.98; p = 0.001), sleep duration of ≥ 8 h relative to 6-8 h (OR = 1.73, 95% CI, 1.29-2.31; p < 0.001), and depression relative to no depression (OR = 1.67, 95% CI, 1.41-1.97; p < 0.001). The risk of cognitive impairment was lower in participants living in the urban areas relative to the rural areas (OR = 0.57, 95% CI, 0.47-0.69; p < 0.001) and consuming alcohol once a month relative to never consuming alcohol (OR = 0.69, 95% CI, 0.51-0.94; p = 0.02).

Conclusion

Cognitive impairment prevalence was high in the Chinese elderly population. The potentially modifiable risk factors for cognitive impairment should be further assessed in the development of interventions for the elderly Chinese population.

Sleep Pattern Is Related to Mental Health among Chinese Collegiate Student Athletes

Regarding the association between sleep and napping duration and mental health in young and older adults, some studies indicated a positive association, while others indicated a negative, or no, association between them. Moreover, collegiate student athletes have different mental health stressors, such as training pressure, improving sports performance, and relationships with coaches. Therefore, sleep is important for athletes. Whether sleep duration is related to their mental health is unclear. Thus, this study aimed to examine the association between nighttime sleep duration, daytime napping duration, and mental health among collegiate student athletees. This cross-sectional study included 700 college athletes. Sleep and daytime napping durations were assessed using a self-reported questionnaire. The Zung Self-rating Depression Scale and Generalized Anxiety Disorder-7 assessed mental health. A multivariate logistic regression analysis was conducted to examine the adjusted association between sleep duration and mental health. In this study, the odds ratios for depression and anxiety symptoms were significantly higher for short sleep duration (<7 h). Additionally, a significant positive association was found between daytime napping duration and the prevalence of depression. This study indicates that short nighttime sleep and long daytime napping duration may be risk factors for collegiate student athletes’ mental health, having important implications for educators and coaches.

Multidimensional sleep health is associated with mental well-being in Australian adults

The few studies assessing the relationship between mental health and a multidimensional measure of sleep have been conducted in samples of almost exclusively women. In the present study, we therefore assessed associations of multidimensional sleep health with mental well-being in Australian adults. A cross-sectional, national online survey of sleep health was conducted in 2019 in 2,044 community dwelling adults aged 18-90 years. Composite scores of self-reported healthy sleep were based on Ru-SATED (R-SATED) dimensions of satisfaction, alertness, timing, efficiency and duration scored 0 (never/rarely), 1 (sometimes) or 2 (usually/always), and regularity (social jet lag) was scored 0 (≥1 hr) or 1 (<1 hr). Mental well-being was identified by a report of no problem on the EuroQol (European quality of life) five dimension five level scale (EQ-5D-5L) anxiety/depression scale, as well as absence of six chronic depressive symptoms. Ordinal logistic regression analyses determined associations of mental well-being with sleep dimensions, and total R-SATED (range 0-11) and SATED scores (0-10), adjusted for sociodemographic and health factors. In males and females, healthy categories of SATED dimensions (but not regularity) were associated with mental well-being. A 1 unit increase in the total SATED score (mean [SD] 6.6 [2.1]) was associated with less problems on the EQ-5D-5L (odds ratio [OR] 1.11, 95% confidence interval [CI] 1.08-1.14) and fewer chronic depressive symptoms (OR 1.20, 95% CI 1.17-1.23). These estimates did not differ when the total R-SATED score was considered. Sleep health promotion focussing solely on traditional messaging around healthy sleep duration may limit mental health gains. Rather, a more holistic approach to public health messaging to improve sleep health literacy may be beneficial for mental well-being.