Sleep Duration and Frailty Risk among Older Adults: Evidence from a Retrospective, Population-Based Cohort Study

Weekend catch-up sleep and frailty in US adults: a cross-sectional study from NHANES 2017-2020

BACKGROUND

Frailty is an age-related condition characterized by vulnerability to adverse health outcomes. Adequate sleep may reduce frailty risk, many individuals rely on weekend catch-up sleep (WCS) to offset weekday deficits. However, the relationship between WCS and frailty remains poorly understood. This study aims to clarify the association between WCS and frailty.

METHODS

We conducted secondary data analyses using data from 7714 adult participants in the National Health and Nutrition Examination Survey (NHANES 2017-2020). Sleep duration was assessed through self-reported questions, while frailty was evaluated using the frailty index. WCS duration was then computed as the difference between weekend and weekday sleep durations, with WCS defined as WCS duration ≤ 0 h, 0-2 h, or ≥ 2 h. A frailty index of 0.25 or greater is considered frailty. Multivariate logistic regression analyses were conducted to explore the association between WCS and frailty.

RESULTS

In fully adjusted models, participants with 0-2 h of WCS had significantly lower odds of frailty (OR 0.709; 95% CI, 0.518-0.969; P = 0.035) compared to those with no WCS (≤ 0 h). However, the association was not significant for those with ≥ 2 h of WCS (OR 0.812; 95% CI, 0.550-1.200; P = 0.248). Subgroup analyses indicated no significant interaction across subgroups (P for interaction > 0.05).

LIMITATIONS

The cross-sectional design limits our ability to infer causality, and the reliance on self-reported sleep data may introduce measurement bias. Additionally, the frailty index, while validated, may not capture all dimensions of frailty. Future longitudinal studies with objective sleep measurements are needed to confirm these findings.

CONCLUSIONS

Our findings suggest that moderate WCS (0-2 h) may be associated with a lower prevalence of frailty, although the relationship is not linear and requires further investigation. These findings contribute to the emerging evidence base linking sleep patterns with frailty risk, warranting further prospective investigation.

Sleep disorders and the association with frailty among community-dwelling older adults in Northwest China: a cross-sectional study

OBJECTIVES

To investigate the status of sleep disorders and their association with comprehensive frailty in the community-dwelling older adults.

DESIGN

A cross-sectional study.

SETTING

Six community healthcare centres in Xi'an City, Northwest China.

PARTICIPANTS

A total of 2647 community-dwelling older adults completed the study.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcomes included frailty and sleep disorders, measured with the Comprehensive Frailty Assessment Instrument and Pittsburgh Sleep Quality Index (PSQI), respectively. The secondary outcomes were potential factors associated with frailty.

RESULTS

The participants averaged 5.23±2.94 in the total score of the PSQI, with a poor sleep quality prevalence of 19.9%. Individuals with poor sleep quality are more likely to have mild and high frailty, with an OR of 1.64 and 2.81, respectively. Both shortened (<5 hours) and prolonged (>8 hours) sleep duration are associated with higher level of frailty. Poor overall sleep, poor subjective sleep quality, extended sleep latency, sleep disturbances, use of sleeping medication and daytime dysfunction were associated with higher level of frailty (with a correlational coefficient of 0.237, 0.201, 0.223, 0.197, 0.087 and 0.378, respectively).

CONCLUSION

Sleep disorders are common problems among community-dwelling older adults, the severity of which rises with the increase in frailty level. Poor overall sleep quality, poor subjective sleep quality, extended sleep latency, sleep disturbances, daytime dysfunction and abnormal sleep duration are associated with frailty.

Sleep quality and duration and frailty in older adults: a systematic review

Introduction

Sleep problems and frailty are associated with adverse health outcomes in older adults, including mortality, and constitute a major public health challenge.

Objective

This study investigated the association between sleep quality and duration and frailty in older adults, with emphasis on methods of evaluation.

Methods

This systematic review was guided by the Preferred Reporting Items for Systematic Reviews and MetaAnalyses (PRISMA). The Embase, Medline (Pubmed) and Cochrane libraries were searched, with no time restrictions for publications.

Results and discussion

Of the 17 studies included in this review, all published between 2009 and 2024, 13 were cross-sectional and only four were longitudinal. The Pittsburgh Sleep Quality Index and the Fried phenotype were widely used as methods to assess, respectively, sleep and frailty. Studies evaluating insomnia and frailty by the Fried phenotype all found an independent association. Poor sleep quality was independently associated with pre-frailty and frailty. Sleep onset insomnia, but not sleep maintenance insomnia, was associated with frailty. Short (5 h) and long (9 h) sleep duration were also associated with frailty. Poor sleep quality was associated with pre-frailty and frailty in older adults. The results show a wide diversity of methods for assessing both exposure (sleep quality) and outcome (frailty) and point to a need for further - especially longitudinal - research on the relationship between sleep and frailty.

Bidirectional causal associations between frailty measures and sleep disturbances: a two-sample Mendelian randomization study

Background

Observational studies have demonstrated a strong association between sleep disturbances and frailty. However, the causality remains inconclusive. We aimed to investigate the bidirectional causal relationships between frailty measures and sleep disturbances employing a two-sample Mendelian randomization (MR) analysis.

Methods

Two-sample MR analyses were performed based on large-scale genome-wide association studies (GWAS) of the European population for frailty index (FI) (N = 175,226), Fried Frailty Score (FFS) (N = 386,565), insomnia (N = 283,595), sleep duration (N = 445,966) and sleep apnea (N = 523,366). We conducted the causal estimates using the inverse variance-weighted method (IVW), with sensitivity analyses using MR-Egger, weighted median, weighted mode, and MR pleiotropy residual sum and outlier (MR-PRESSO) analysis. Cochran's Q test was performed to assess heterogeneity.

Results

We found that genetically predicted FI was associated with shorter sleep duration and sleep apnea. The genetically predicted FFS was associated with insomnia, shorter sleep duration, and sleep apnea. In the reverse direction analysis, genetic liability to insomnia, short sleep duration, and long sleep duration were associated with an increase in FI. Genetic liability to short sleep duration and long sleep duration were associated with an increase in FFS.

Conclusion

Our study provided genetic evidence supporting the bidirectional causality between frailty measures and sleep disturbances. The findings contribute to the prevention and management of frailty and sleep disturbances.

The Interplay between nighttime/midday sleep duration and the number of new-onset chronic diseases: A decade-long prospective study in China

OBJECTIVE

To investigate the interplay between individual nighttime and midday sleep duration and the number of new-onset chronic diseases and determine the optimal sleep duration associated with lowest number of new-onset chronic diseases.

METHODS

We used data from the China Health and Retirement Longitudinal Study (CHARLS) covering a decade and involving 10,828 participants. A random intercept cross-lagged model was used to explore the interplay between nighttime/midday sleep durations and new-onset chronic diseases at both the within-individual and between-individual levels, followed by a dose-response analysis at the between-individual level to determine the optimal sleep duration. New-onset chronic diseases include 14 types of self-reported diseases diagnosed by doctors.

RESULTS

Within-individual analysis revealed that increased nighttime/midday sleep duration led to a higher number of new-onset chronic diseases, and an increased number of new-onset chronic diseases resulted in decreased nighttime sleep duration. Between nighttime and midday sleep, one type of sleep duration increase was likely to lead to an increase in another type. Between-individual analysis found a nonlinear relationship between the number of new-onset chronic diseases and nighttime sleep duration, identifying the optimal nighttime sleep duration as 7.46 h.

CONCLUSIONS

These findings elucidate the interplay between sleep duration and number of new-onset chronic diseases and underscore the need for public awareness and comprehensive interventions. Future studies should focus on refining sleep monitoring and exploring the sleep-chronic diseases nexus in greater depth.

Effects of activities participation on frailty of older adults in China

Objective

Frailty represents a significant health challenge among older adults, necessitating effective interventions to enhance their overall wellbeing. This study aims to investigate the impact of various types of activity participation on frailty in older adults and to elucidate their intrinsic associations, thereby providing a basis for targeted interventions.

Methods

This study constructed a classification of activities based on the framework proposed by the WHO regarding functional ability in healthy aging, innovatively dividing activities into five categories: physical activity, social activity, economic activity, information activity and sleep activity. Utilizing data from the China Health and Retirement Longitudinal Study (CHARLS 2020), the research employed multiple linear regression and mediation analysis to explore the effects of these activities on the frailty status of older adults and their underlying mechanisms. Furthermore, propensity score matching was conducted to robustly test the regression results.

Results

The study found that physical activity (β = -0.006, p < 0.01), social activity (β = -0.007, p < 0.01), economic activity (β = -0.017, p < 0.01), information activity (β = -0.040, p < 0.01) and sleep activity (β = -0.044, p < 0.01) all had significant positive effects on the frailty status of older adults. Additionally, sleep activity mediated the relationship between physical activity and frailty status, accounting for 4.819%. Social activity mediated the relationship between information activity and frailty status, accounting for 7.692%.

Conclusion

Older adults should enhance their participation in various activities to alleviate frailty. This can be further improved through the following three aspects: engaging in moderate physical exercise, fostering and promoting awareness of volunteer services, and popularizing the use of information technology.

Association between single and multiple cardiometabolic diseases and all-cause mortality among Chinese older adults: A prospective, nationwide cohort study

BACKGROUND AND AIM

Cardiometabolic diseases (CMDs) are leading causes of death and disability, but little is known about the additive mortality effects of multiple CMDs. This study aimed to examine the association between single and multiple CMDs and all-cause mortality among older Chinese population.

METHODS AND RESULTS

Using the Chinese Longitudinal Healthy Longevity Survey (CLHLS) database, we analyzed data from 2008 to 2018 to assess the relationship between CMDs and mortality. Cox regression models estimated hazard ratios (HRs) and 95% confidence intervals (CIs) for single and multiple CMDs. At baseline, 11,351 participants (56.9% female) aged 60 years or older were included. 11.91% of participants had a single CMD, 1.51% had two CMDs, and 0.22% had three CMDs. Over a decade follow-up, 8992 deaths (79.2%) were recorded. A dose-response relationship was observed, with the mortality risk increasing by 17% for each additional disease. The fully-adjusted HRs for all-cause mortality were 1.16, 1.36, and 2.03 for one, two, and three CMDs, respectively. Larger effects of single and multiple CMDs were observed in the male group (P = 0.015) and the younger senior group (P < 0.001).

CONCLUSIONS

This large-scale study found that CMDs multiply mortality risks, especially in younger seniors and males. The risk is highest when heart disease and stroke coexist, and diabetes further increases it. Public health efforts should prioritize evidence-based management and prevention of CMDs.

Causality between sleep traits and the risk of frailty: a Mendelian randomization study

Background

Research based on observation has demonstrated a relationship between sleep traits and frailty; however, it remains uncertain if this correlation indicates causation. The purpose of this study was to look at the causal relationship that exists between frailty and sleep traits.

Method

Using summaries from a genome-wide association study of self-reported sleep features and frailty index, we performed a bidirectional Mendelian randomization (MR) analysis. Examining the causal relationships between seven sleep-related traits and frailty was the goal. The major method used to calculate effect estimates was the inverse-variance weighted method, supplemented by the weighted median and MR-Egger approaches. The study investigated pleiotropy and heterogeneity using several methodologies, such as the MR-Egger intercept, the MR-PRESSO approach, and the Cochran's Q test. We took multivariate Mendelian randomization and genetic correlations between related traits to enhance the confidence of the results. Furthermore, we used MRlap to correct for any estimation bias due to sample overlap.

Results

Insomnia, napping during the day, and sleep apnea syndrome exhibited a positive connection with the frailty index in forward MR analysis. Conversely, there is a negative link between getting up in the morning, snoring and sleep duration with the frailty index. During the reverse MR analysis, the frailty index exhibited a positive correlation with insomnia, napping during the day, and sleep apnea syndrome, while demonstrating a negative correlation with sleep duration. There was no direct correlation between snoring, chronotype, and frailty. In MVMR analyses, the causal effect of sleep characteristics on frailty indices remained consistent after adjusting for potential confounders including BMI, smoking, and triglycerides.

Conclusion

The findings of our investigation yield novel evidence that substantiates the notion of a bidirectional causal connection between sleep traits and frailty. Through the optimization of sleep, it is potentially feasible to hinder, postpone, or even reverse the state of frailty, and we proposed relevant interventions.

Association of daytime napping and nighttime sleep with all-cause mortality: A prospective cohort study of China Health and Retirement Longitudinal Study

STUDY OBJECTIVES

The correlation of daytime napping and nighttime sleep duration on mortality was inconsistent. We aimed to explore their separate links to all-cause/premature mortality, and evaluate their combined impact on all-cause mortality risk.

METHODS

All of 20617 (mean age: 56.90 ± 10.19, 52.18 % females) participants from China Health and Retirement Longitudinal Study were followed for a median of 7 years (interquartile range: 4-7) to detect death status. Baseline self-reported napping and sleep duration was categorized: napping as none, <60 min, 60-90 min, and ≥90 min, sleep as <6 h/night, 6-8 h/night, and ≥8 h/night. Death event was tracked, and premature death was defined using 2015 China's average life expectancy (73.64 years for men, and 79.43 years for women). Cox regression models analyzed the data.

RESULTS

During follow-up, 1621 participants (7.86 %) died, including 985 (4.78 %) premature deaths. Compared to none nappers, napping ≥90 min associated with a higher risk of all-cause mortality (Hazard ratio, [HR] 1.23, 95 % confidence interval [CI] 1.06-1.42) and premature mortality (HR 1.23, 95 % CI 1.02-1.49), while napping <60 min correlated with a lower risk of premature mortality (HR 0.71, 95 % CI 0.54-0.95), after adjustment. Compared to sleep 6-8 h/night, nighttime sleep ≥8 h was associated with an increased risk of all-cause mortality (HR 1.20, 95 % CI 1.04-1.37) and premature mortality (HR 1.28, 95 % CI 1.08-1.52). Participants napping ≥90 min and sleeping ≥8 h had a multi-adjusted HR (95%CI) of 1.50 (95 % CI 1.17-1.92) for all-cause mortality, versus no napping and 6-8 h/night sleep.

CONCLUSIONS

Prolonged napping and extended nighttime sleep linked to increased mortality risk, particularly in combination. Optimizing sleep patterns may have potential implication in mortality prevention.

Does testosterone influence the association between sleep and frailty in men: results from the European Male Aging Study

BACKGROUND

Previous studies have suggested an association between sleep disturbance and frailty. The mechanism is unknown, although it has been suggested that hormonal factors may play a role.

METHODS

The aim was to determine the association between sleep duration, sleep quality and frailty, and to determine whether testosterone influenced this association. Males aged 40-79 years were recruited from eight European centres to the European Male Aging Study (EMAS). Subjects completed an interviewer-assisted questionnaire including questions regarding sleep quality and duration. Sleep quality was scored 0-20 and categorised as 0-4, 5-9, 10-14, and 15-20, with higher scores indicating poorer quality. A 39-component frailty index (FI) was constructed. Total testosterone levels were measured. The association between sleep duration, sleep quality and the FI was assessed using negative binomial regression, with adjustment for putative confounders including testosterone level.

RESULTS

Two thousand three hundred ninety-three participants contributed data to the analysis. The mean age was 63.3 years and mean sleep duration was 7.01 h. The mean frailty index was 0.15. Mean testosterone levels declined with decreasing sleep quality. After adjustment, compared to those with a sleep score of 0-4, the FI was 57% (95% CI 38%, 78%) higher among those with a sleep score of 15-20. After adjustment compared to those with normal sleep duration (6-9 h), those with a short (< 6 h) and long (≥ 9 h) sleep duration had a 16% (95% CI 6%, 28%) and 11% (95% CI 0%, 23%) higher FI, respectively. Adjustment for testosterone did not influence the strength of either association.

CONCLUSION

Frailty is associated with impaired sleep quality and sleep duration. The association cannot, however, be explained by variation in testosterone levels.

Association between daytime nap duration and risks of frailty: Findings from the China Health and Retirement Longitudinal Study

Introduction

Night sleep duration and total sleep duration are associated with frailty. However, the association between daytime nap duration and the risks of frailty has not been explored thoroughly.

Methods

This study used data from the China Health and Retirement Longitudinal Study (CHARLS). Participants aged 60 years and older at baseline were included in this study. Individuals with daytime nap duration were categorized into four groups: no napping, short napping (< 30 min), moderate napping (30-89 min), and extended napping (≥90 min). Frailty was assessed using a modified Physical Frailty Phenotype (PFP) scale. Non-frail participants at baseline were followed up for 4 years. The association between nap duration and risks of frailty at baseline and incident frailty was evaluated by logistic regression and discrete-time Cox regression analyses, respectively.

Results

In total, 5,126 participants were included in this study. For individuals with night sleep duration of ≥9 h, short nappers showed higher odds [odds ratio (OR) = 4.08, 95% confidence interval (CI): 1.30-12.78] for frailty compared with non-habitual nappers at baseline, while moderate nappers were less likely to be frail (OR = 0.18, 95% CI: 0.04-0.73). In the follow-up study, short nappers showed higher risks for frailty compared with participants of the no napping group with night sleep duration of < 6 h [hazard ratio (HR) = 1.91, 95% CI: 1.07-3.43] or 6-9 h (HR = 1.97, 95% CI: 1.18-3.30). Compared with short nappers, older adults with extended napping (HR = 0.41, 95% CI: 0.22-0.77) showed lower risks for frailty in those with night sleep duration of 6-9 h. For individuals with night sleep duration of ≥9 h, moderate napping (HR = 0.20, 95% CI: 0.05-0.77) decreased the risks for frailty compared with short napping.

Conclusion

Among older adults with night sleep duration of < 9 h, short nappers posed higher risks for frailty compared with non-habitual nappers. Extended naps for those with a night sleep duration of 6-9 h or moderate naps for those with night sleep duration of ≥9 h could lower the risk of frailty compared with short naps. Future studies on the timing, purpose, frequency, and quality of daytime napping and objectively measured nap duration are needed to explore the association between daytime napping and risks of frailty.

Age Group Differences in the Association Between Sleep Status and Frailty Among Community-Dwelling Older Adults: The SONIC Study

Objective: We aimed to determine whether the association of sleep status with frailty differs between age groups of older adults. Method: This cross-sectional study was part of the observational Septuagenarians, Octogenarians, Nonagenarians Investigation with Centenarians (SONIC) study. Subjects were community-dwelling older adults in their 70s and 80s. Frailty was evaluated using the Japanese version of the Cardiovascular Health Study criteria (J-CHS). Pittsburgh Sleep Quality Index (PSQI) was used to assess sleep status. Poor sleep quality was defined as a PSQI global score ≥6. Sleep duration was categorized as short (<6 hr), normal (6-8), and long (>8). We performed multivariable logistic regression to investigate the association between sleep status and frailty separately for each age group adjusted for multiple covariates. Results: In those in their 70s, long sleep duration and sleep medication use were independently associated with frailty. In those in their 80s, poor sleep quality was independently associated with frailty. Conclusions: The association between sleep status and frailty was different between age groups. The findings underscore the importance of incorporating the evaluation of sleep quantity and non-pharmacological therapies in those in their 70s and the evaluation of sleep quality in those in their 80s to help prevent the onset of frailty.

Relationships between Inflammation and Age-Related Neurocognitive Changes

The relationship between inflammation and age-related neurocognitive changes is significant, which may relate to the age-related immune dysfunctions characterized by the senescence of immune cells and elevated inflammatory markers in the peripheral circulation and the central nervous system. In this review, we discuss the potential mechanisms, including the development of vascular inflammation, neuroinflammation, organelle dysfunctions, abnormal cholesterol metabolism, and glymphatic dysfunctions as well as the role that the key molecules play in the immune-cognition interplay. We propose potential therapeutic pharmacological and behavioral strategies for ameliorating age-related neurocognitive changes associated with inflammation. Further research to decipher the multidimensional roles of chronic inflammation in normal and pathological aging processes will help unfold the pathophysiological mechanisms underpinning neurocognitive disorders. The insight gained will lay the path for developing cost-effective preventative measures and the buffering or delaying of age-related neurocognitive decline.