Correlation among sleep quality, physical frailty and cognitive function of the older adults in China: the mediating role

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.

The Association between Circadian Syndrome and Frailty in US adults: a cross-sectional study of NHANES Data from 2007 to 2018

PURPOSE

Frailty and Circadian Syndrome (CircS) are prevalent among the elderly, yet the link between them remains underexplored. This study aims to examine the association between CircS and frailty, particularly focusing on the impact of various CircS components on frailty.

MATERIALS AND METHODS

We conducted a cross-sectional analysis using data from the National Health and Nutrition Examination Survey (NHANES) spanning 2007 to 2018. The 49-item Frailty Index (FI) was employed to assess frailty. To understand the prevalence of CircS in relation to frailty, we applied three multivariate logistic regression models. Additionally, subgroup and interaction analyses were performed to investigate potential modifying factors.

RESULTS

The study included 8,569 participants. In fully adjusted models, individuals with CircS showed a significantly higher risk of frailty compared to those without CircS (Odds Ratio [OR] = 2.18, 95% Confidence Interval [CI]: 1.91-2.49, p < 0.001). A trend of increasing frailty risk with greater CircS component was observed (trend test p < 0.001). Age (p = 0.01) and race (p = 0.02) interactions notably influenced this association, although the direction of effect was consistent across subgroups. Sensitivity analysis further confirmed the strength of this relationship.

CONCLUSION

This study identifies a strong positive correlation between CircS and frailty in the elderly. The risk of frailty escalates with an increasing number of CircS components. These findings highlight the intricate interplay between circadian syndrome and frailty in older adults, offering valuable insights for developing targeted prevention and intervention strategies.

Risk stratification for frailty, impairment and assessment of sleep disorders in community-dwelling older adults

BACKGROUND

Frailty is associated with an increased susceptibility to functional decline, impairment, hospitalization, and mortality among the older adults. However, the potential reversibility of frailty lies in identifying modifiable factors that could prevent, mitigate, or interrupt its progression. While there is a suggestion that sleep disorders may increase the risk of frailty and impairment, the risk stratification of this relationship remains inconclusive.

OBJECTIVE

Stratify the risk of frailty and impairment and investigate potential connections with sleep quality, excessive daytime sleepiness, and the risk of obstructive sleep apnea in older adults dwelling in the community.

METHODS

This was a quantitative cross-sectional investigation. Frailty risk and impairment were stratified using the Frail Non-disabled Questionnaire (for impairment) and the FRAIL Scale (for Frailty). The assessment of excessive daytime sleepiness, sleep quality, and the risk of obstructive sleep apnea involved the employment of the Epworth Sleepiness Scale, Pittsburgh Sleep Quality Index, and the STOP-BANG questionnaire, respectively.

RESULTS

A total of 109 older adults living in the urban area (86 %, p = 0.010), females (61 %; p = 0.030), median age 68 (64-75) years, with overweight (36 %, p < 0.010) and self-identified as belonging to other racial or ethnic categories (71 %, p < 0.010). According to the impairment assessment, 32 % of participants were classified as disable (p < 0.01). Conversely, as per the frailty evaluation, 33 % were pre-frail and 25 % were identified as frail. Additionally, a substantial proportion experienced poor sleep quality (80 %, p = 0.010), exhibited a moderate risk of obstructive sleep apnea (49 %, p < 0.010), and showed no signs of excessive daytime sleepiness (62 %, p < 0.010). There was a modest correlation between frailty and impairment with poor sleep quality (rho = 0.39; p < 0.001) and the risk of obstructive sleep apnea (rho = 0.26; p = 0.000). However, the was no significant relationship was observed between frailty and impairment and excessive daytime sleepiness (rho = 0.04; p = 0.660). Similarly, a modest correlation was observed between sleep quality (rho = 0.33; p < 0.001), the risk of obstructive sleep apnea (rho = 0.27; p = 0.001), and frailty. Conversely, no correlation was found with excessive daytime sleepiness (rho = 0.05; p = 0.590). Also, the poor sleep quality and the risk of obstructive sleep apnea explain 14 % of the risk of frailty in the population of community-dwelling older adults (r2 = 0.14; p = 0.04).

CONCLUSION

This study reveals a modest risk of frailty and impairment with sleep quality and the risk of obstructive sleep apnea, but not with excessive daytime sleepiness in community-dwelling older adults.