Sleep Duration Change and Cognitive Function: A National Cohort Study of Chinese People Older than 45 Years

Associations between sleep duration trajectories and cognitive decline: A longitudinal cohort study in China

OBJECT

The relationship between sleep duration trajectories and cognitive decline remains uncertain. This study aims to examine the connections between various patterns of sleep duration and cognitive function.

METHODS

Group-based trajectory modeling (GBTM) was employed to identify longitudinal trajectories of sleep duration over four-year follow-up period, while considering age, sex and nap duration as adjustments. Logistic regression was utilized to analyze the association between sleep trajectories and cognition, with odds ratios (OR) and 95 % confidence intervals (CI) reported. Subgroup analyses based on various demographic characteristics were conducted to explore potential differences in sleep trajectories and cognitive decline across different population subgroups.

RESULTS

A total of 5061 participants were followed for four years, and three sleep duration trajectories were identified: high increasing (n = 2101, 41.6 %), stable increasing (n = 2087, 40.7 %), and low decreasing (n = 873, 17.7 %). After adjustment for basic demographic information, health status, and baseline cognition, the high increasing trajectory was found to be associated with cognitive decline in terms of global cognition (OR:1.52,95 %CI:1.18-1.96), mental intactness (OR:1.36,95 %CI:1.07-1.73) and episodic memory (OR:1.33, 95 %CI:1.05-1.67), as compared to stable increasing trajectory. These associations were particularly prominent among the non-elderly population (≤65 years) and those without depressive symptoms.

CONCLUSION

This study suggests that both high increasing and low decreasing sleep duration trajectories are linked to cognitive decline, as compared to the stable increasing trajectory. Long-term attention to changes in sleep duration facilitates early prevention of cognitive decline.

Gender-and age-specific associations of sleep duration and quality with cognitive impairment in community-dwelling older adults in Anhui Province, China

Objective

To examine associations of sleep duration and quality with cognitive impairment in older adults and the moderating role of gender and age in these associations.

Methods

This community-based cross-sectional study included 4,837 participants aged 60 years and above. Cognitive function was assessed using the Chinese version of the Mini-Mental State Examination (MMSE), and the participants were grouped based on the presence of cognitive impairment. The duration and quality of sleep were assessed using the Pittsburgh Sleep Quality Index (PSQI). Multivariate logistic regression models were used to analyze associations of sleep duration and quality with cognitive impairment. The role of age and gender in these associations have also been explored.

Results

The age (mean ± SD) of the participants was 71.13 ± 5.50 years. Of all older adults, 1,811 (37.44%) were detected as cognitive impairment, and 1755 (36.8%) had poor sleep quality. Among those with cognitive impairment, 51.09% were female. The proportion of the participants with cognitive impairment is significantly higher in those with symptoms of depression (49.73%, 273/549) (χ2 = 41.275, p < 0.001) than in those without depressive symptoms. After adjustment for multiple confounding factors and the crucial covariate (depressive symptoms), the odds ratios (OR) (95% confidence interval [CI]) of cognitive impairment (with 7-7.9 h regarded as the reference group) for individuals with a sleep duration of <6, 6-6.9, 8-8.9, and ≥ 9 h were 1.280 (1.053-1.557), 1.425 (1.175-1.728), 1.294 (1.068-1.566), and 1.360 (1.109-1.668), respectively. Subgroup analysis showed a V-shaped association between night sleep duration and cognitive impairment in males (p ≤ 0.05), and the association was stronger for individuals aged 60-80 years. With regard to sleep quality, the fully adjusted OR (95%CI) of cognitive impairment were 1.263 (1.108-1.440). According to scores of subscales in the PSQI, daytime dysfunction was associated with an increased risk of cognitive impairment (OR: 1.128, 95%CI: 1.055-1.207). Subgroup analysis also revealed a statistically significant correlation between poor sleep quality (including daytime dysfunction) and cognitive impairment in different gender and age groups, with the association being stronger in females (OR: 1.287, 95%CI: 1.080-1.534) and those aged 81-97 years (OR: 2.128, 95%CI: 1.152-3.934). For cognitive impairment, the group aged 81-97 years with daytime dysfunction was associated with a higher odds ratio than other age groups.

Conclusion

The present study showed that inadequate or excessive sleep was associated with cognitive impairment, especially in males, who exhibited a V-shaped association. Cognitive impairment was also associated with poor sleep quality as well as daytime dysfunction, with females and individuals aged 81-97 years exhibiting the strongest association.

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.

Serum Vitamin D3 Concentration, Sleep, and Cognitive Impairment among Older Adults in China

BACKGROUND

Cognitive decline in older adults has become one of the critical challenges to global health. This study aims to examine both cross-sectional and longitudinal associations of levels of serum 25-hydroxyvitamin D3 (25(OH)D3) (briefed as VD3) concentration and sleep quality/duration, especially their interactions, with risk of cognitive impairment among older adults in China.

METHODS

We utilized a special subsample of adults aged 65-105 years (individuals = 3412, observations = 4816) from eight provinces in China derived from the 2011/2012 and 2014 waves of the Chinese Longitudinal Healthy Longevity Survey. Cognitive impairment was measured by the Mini-Mental State Examination scale. Sleep quality was classified as good versus fair/poor, and sleep duration was classified into short (<7 h), normal (≥7 but <9 h), and long (≥9 h). The VD3 concentration was divided into three levels: deficiency (VD3 < 25 nmol/L), insufficiency (25 nmol/L ≤ VD3 < 50 nmol/L), and sufficiency (VD3 ≥ 50 nmol/L). A wide set of covariates that include demographics, socioeconomic status, family support, health practice, and health conditions was adjusted for robust findings. Multilevel random intercept logit regression models were used to examine the cross-sectional associations between VD3, sleep, and cognitive impairment, whereas logit regression models were applied to investigate the longitudinal associations.

RESULTS

In the cross-sectional analyses, when all covariates were adjusted, VD3 sufficiency was significantly associated with a 33% lower risk of cognitive impairment compared with VD3 deficiency; good sleep quality was associated with 34% lower odds of cognitive impairment compared with fair/poor sleep quality; sleep hours were not associated with cognitive impairment, although a long sleep duration (≥9 h) was associated with 30% higher odds of being cognitively impaired when baseline health was not controlled. Interaction analyses reveal that VD3 sufficiency could help to additionally reduce the risk of cognitive impairment for good sleep quality and normal sleep hours. In the longitudinal analyses, the association of VD3 sufficiency remains significant, whereas sleep quality and sleep duration were not significant associates.

CONCLUSIONS

Good sleep quality, normal sleep hours, and VD3 sufficiency are positively associated with good cognitive function. VD3 sufficiency could enhance the associations between sleep and cognitive impairment.

Incidence of cognitive impairment after hypothetical interventions on depression, nighttime sleep duration, and leisure activity engagement among older Chinese adults: An application of the parametric g-formula

Background

Cognitive impairment is an age-relevant intermediate stage where cognition declines to a state between the normal aging process and dementia. Earlier studies reported that depression, inappropriate nighttime sleep duration (NSD), and limited leisure activity engagement are cognitive impairment risk factors among older adults. Thus, we postulated that interventions on depression, sleep duration, and leisure activity engagement can reduce cognitive impairment risk. However, no earlier research ever explored this.

Methods

The data of 4,819 respondents aged 60 years and above, without cognitive impairment at baseline and with no prior history of memory-related diseases, including Alzheimer's disease, Parkinson's disease, and encephalatrophy, were obtained from the China Health and Retirement Longitudinal Study (CHARLS) between 2011 and 2018. The parametric g-formula, an analytic tool for estimating standardized outcome distributions using covariate (exposure and confounders)-specific estimates of the outcome distribution, was used to estimate 7-year cumulative cognitive impairment risks among older Chinese adults, under independent hypothetical interventions on depression, NSD, and leisure activity engagement, which was subdivided into social activity (SA) and intellectual activity (IA) for the different intervention combinations.

Results

The observed cognitive impairment risk was 37.52%. Independent intervention on IA was the most effective factor in reducing incident cognitive impairment, with a risk ratio (RR) of 0.75 (95% confidence interval [CI]: 0.67-0.82), followed by depression (RR: 0.89, 95% CI: 0.85-0.93) and NSD (RR: 0.88, 95% CI: 0.80-0.95). The joint intervention combining depression, NSD, and IA interventions could reduce the risk by 17.11%, with an RR of 0.56 (95% CI: 0.48-0.65). In subgroup analyses, independent interventions on depression and IA had analogously significant effects on men and women. However, interventions on depression and IA had stronger effects on literate than illiterate individuals.

Conclusions

Hypothetical interventions on depression, NSD, and IA reduced cognitive impairment risks among older Chinese adults, both independently and jointly. The findings of the present study suggest that the intervention measures on depression, inappropriate NSD, limited intellectual activities, and their combination may prove to be effective strategies for preventing cognitive impairment among older adults.

Modifiable and Non-modifiable Factors Associated with Low Awareness of Hypertension Treatment in Indonesia: A Cross-Sectional Population-Based National Survey

Introduction:

Low awareness about hypertension treatment is recognized as a significant cause of treatment failure. Therefore, identifying its underlying factors is essential for developing effective intervention strategies. This study aims to identify the modifiable and non-modifiable factors associated with low awareness about hypertension treatment.

Method:

This national, cross-sectional, population-based survey used publicly available data from the Indonesian Family Life Survey (IFLS-5) for 2014 among respondents with hypertension aged ≥15 years. Depression and insomnia, as modifiable factors, were assessed using the Centre for Epidemiologic Studies—Depression (CES-D) and the Patient-Recorded Outcomes Measurement Information System (PROMIS) questionnaire, respectively. Non-modifiable factors, such as sociodemographic information, were obtained from self-reported data. Logistic regression analysis was used to assess the association between these factors and low awareness about hypertension treatment. Odds ratios (ORs) with 95% confidence intervals (CIs) were reported.

Result:

The study recruited 7,920 respondents, the majority of whom were female (53.8%) and aged <60 years (71.1%). The prevalence of low awareness of hypertension treatment was 87.1% (51.8% in women and 48.2% in men). Being an elderly (OR: 1.60, 95%CI 1.36–1.88), being irregularly blood pressure control (OR: 4.40, 95% CI 3.78–5.13), having depressive symptoms (OR: 1.35, 95% CI 1.12–1.62), having insomnia (OR: 1.31, 95% CI 1.11–1.53), and having low satisfaction with health care (OR: 1.28, 95% CI 1.08–1.51) were associated with low awareness of hypertension treatment. Surprisingly, respondents with strong religiosity (OR: 1.62; 95% CI 1.25–2.09) were more likely to display low awareness of hypertension treatment.

Conclusion:

The main factors associated with low awareness of hypertension treatment are modifiable. Thus, health care professionals should integrate more patient-specific factors when designing tailored interventions.

Sex Modified the Association between Sleep Duration and worse Cognitive Performance in Chinese Hypertensive Population: Insight from the China H-Type Hypertension Registry Study

Objectives

Cognitive decline could be seen as the sign of preclinical phase of dementia, which was found to be sex differentiated. Previous studies had discovered that there might be some link between abnormal sleep duration and cognitive performance. Additionally, hypertension was found to be one of the important risk factors for cognitive decline and abnormal sleep duration was also a significant risk factor for hypertension. Therefore, the purpose of this study was to investigate sex differences in the association of sleep duration with cognitive performance and to further explore potential effect modifiers that may exist.

Methods

Data analyzed in this study was from the China H-type Hypertension Registry Study. Sleep duration was assessed with a sleep questionnaire and categorized as <5 hours, 5-8 hours, and ≥8 hours. Cognitive performance was evaluated with the Mini-Mental State Examination (MMSE).

Result

A total of 9527 subjects were included. The average age was 63.7 ± 9.8 years. Linear regression analyses showed that the association between long sleep duration (≥8 h) and MMSE score adjusting for pertinent covariables was stronger in female (β = −0.95, 95% CI: -1.23 to -0.68, P < 0.001) than in male (β = −0.29, 95% CI: -0.53 to -0.06, P = 0.013). Furthermore, there was a significant interaction between sleep duration and age on cognitive performance only in female.

Conclusion

In summary, this study found that long sleep duration (≥8 h) was associated with poorer cognitive performance. Furthermore, this association was more pronounced in female than in male, especially in older female.