Longitudinal trajectories of disability index and associated factors in Chinese older adults

Nagin D.S., Jones B.L., Elmer J.

Group-based trajectory modeling (GBTM) identifies groups of individuals following similar trajectories of one or more repeated measures. The categorical nature of GBTM is particularly well suited to clinical psychology and medicine, where patients are often classified into discrete diagnostic categories. This review highlights recent advances in GBTM and key capabilities that remain underappreciated in clinical research. These include accounting for nonrandom subject attrition, joint trajectory and multitrajectory modeling, the addition of the beta distribution to modeling options, associating trajectories with future outcomes, and estimating the probability of future outcomes. Also discussed is an approach to selecting the number of trajectory groups. Expected final online publication date for the Annual Review of Clinical Psychology, Volume 20 is May 2024. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Luo M., Dong Y., Fan B., Zhang X., Liu H., Liang C., Rong H., Fei Y.

Background The duration of sleep plays a crucial role in the development of physiological functions that impact health. However, little is known about the associations between sleep duration and functional disability among older adults in China. Objective This study aimed to explore the associations between sleep duration and functional disabilities in the older population (aged≥65 years) in China. Methods The data for this cross-sectional study were gathered from respondents 65 years and older who participated in the 2018 survey of the China Health and Retirement Longitudinal Study, an ongoing nationwide longitudinal investigation of Chinese adults. The duration of sleep per night was obtained through face-to-face interviews. Functional disability was assessed according to activities of daily living (ADL) and instrumental activities of daily living (IADL) scales. The association between sleep duration and functional disability was assessed by multivariable generalized linear models. A restricted cubic-spline model was used to explore the dose-response relationship between sleep duration and functional disability. Results In total, 5519 participants (n=2471, 44.77% men) were included in this study with a mean age of 73.67 years, including 2800 (50.73%) respondents with a functional disability, 1978 (35.83%) with ADL disability, and 2299 (41.66%) with IADL disability. After adjusting for potential confounders, the older adults reporting shorter (≤4, 5, or 6 hours) or longer (8, 9, or ≥10 hours) sleep durations per night exhibited a notably increased risk of functional disability compared to that of respondents who reported having 7 hours of sleep per night (all P<.05), which revealed a U-shaped association between sleep duration and dysfunction. When the sleep duration fell below 7 hours, increased sleep duration was associated with a significantly lower risk of functional disability (odds ratio [OR] 0.85, 95% CI 0.79-0.91; P<.001). When the sleep duration exceeded 7 hours, the risk of functional disability associated with a prolonged sleep duration increased (OR 1.16, 95% CI 1.05-1.29; P<.001). Conclusions Sleep durations shorter and longer than 7 hours were associated with a higher risk of functional disability among Chinese adults 65 years and older. Future studies are needed to explore intervention strategies for improving sleep duration with a particular focus on functional disability.

Lee E., Jun S.S.

This study aimed to identify distinct trajectories of activities of daily living (ADL) disability in older adults aged ≥75 years over 6 years. A growth mixture model and the multinomial logistic regression analysis were used to identify different disability trajectories and to investigate each trajectory. Four distinct disability trajectories were identified: low, moderate, high, and progressive. Activity restriction due to fear of falling, being underweight, impaired vision, and impaired cognition were highly associated with the progressive groups, compared with the low disability group. Activity restriction due to fear of falling, depression, impaired cognition, and poor subjective health status were associated with moderate and high disability. These findings contribute to increasing the understanding of ADL disability among older adults.

Zhang X., Lin L., Sun X., Lei X., Liu G.G., Raat H., Zeng Y.

Abstract Background With the rapid population aging, the challenge to provide care for disabled older adults is becoming bigger. This study aims to develop the Disability Index (DI) to assess disability to indicate care needs, and we evaluated the reliability and validity of the DI among older adults aged 65–105. Methods A total of 12 559 older adults (54.0% women; mean age = 84.3; SD = 11.2) from 22 provinces in China were investigated in 2017–2018. We developed the 21-item DI covering 4 subdomains, including Activities of Daily Living (ADL), Instrumental Activities of Daily Living (IADL), physical performance, and cognitive function. Cronbach’s alpha was used to determine internal consistency. The convergent and divergent validity were assessed by Spearman rank order correlation coefficients and Pearson correlation coefficients. The known-group validity was assessed by Mann–Whitney U tests. The concurrent validity was assessed by the area under the receiver operating characteristic curve (AUC). Results In the total sample, the internal consistency of the full DI and its subdomains were satisfactory with Cronbach’s alpha ≥0.70; the convergent and divergent validity of the 4 subdomains were supported by all the alternative measures; the known-group validity of the full DI and its subdomains were supported by clear discriminative ability; and the concurrent validity of the full DI was supported with all the AUCs ≥0.70. The reliability and validity of the full DI and its subdomains were additionally supported by age subgroups and sex subgroups. Conclusions The DI is a reliable and valid instrument to assess disability status among older adults.

Lee Y., Kong D., Lee Y.H., Lin C., Liu C., Chang Y.

This study examined the associations of activities of daily living (ADL) and instrumental activities of daily living (IADL) with changes in sleep-related measurements among Chinese older adults. Older adults with more ADL and IADL limitations had a higher risk of experiencing declines in sleep quality and the transition from meeting to not meeting the recommended sleep duration over time. Functional limitations need to be considered in sleep hygiene interventions and research. We examined the associations of activities of daily living (ADL) and instrumental activities of daily living (IADL) with changes in sleep-related measurements among Chinese older adults from 2005 to 2014. Four waves of longitudinal data from the Chinese Longitudinal Healthy Longevity Survey (CLHLS; 2005–2014; n = 42,417) were used. Two sleep-related measurements were included: sleep quality and meeting the recommended daily sleep duration (7–8 h). We used Cox two-state regression models to examine the different states of sleep quality and duration. Approximately 43.6% of observations were between 81 and 95 years old, and 35.9% were between 65 and 80 years old. Around 54.8% of observations were female. Older adults with more ADL and IADL limitations had a higher risk of experiencing declines in sleep quality and the transition from meeting to not meeting the recommended sleep duration over time (all p < 0.01). ADL and IADL limitations are significant risk factors for the development of sleep-related issues over time among Chinese older adults. Functional limitations need to be included in intervention strategies focused on sleep hygiene and studies examining changes in sleep patterns over time.

Pan C., Kelifa M.O., Liang J., Wang P.

This study aimed to identify disability trajectories and discover early disablement process factors associated with disability trajectories among older adults in China.This is a prospective cohort study.Data were obtained from five waves of the Chinese Longitudinal Healthy Longevity Survey (CLHLS, 2005 to 2018). The multitrajectory modelling approach was used to estimate the joint trajectories of activity of daily living (ADL) disability and instrumental activity of daily living (IADL) disability. A multinomial regression model was used to investigate how baseline disablement process factors among individuals aged 65-95 years are related to joint disability trajectory groups.We identified three typical joint ADL and IADL disability trajectories. Demographic characters, social participation, community services, disease, impairment and functional limitations can all impact the disability trajectories among older adults.The joint ADL and IADL disability trajectories of older adults are increasing, and the Chinese government should pay more attention to disability process elements to improve disability interventions among older adults.

Sabia S., Fayosse A., Dumurgier J., van Hees V.T., Paquet C., Sommerlad A., Kivimäki M., Dugravot A., Singh-Manoux A.

Sleep dysregulation is a feature of dementia but it remains unclear whether sleep duration prior to old age is associated with dementia incidence. Using data from 7959 participants of the Whitehall II study, we examined the association between sleep duration and incidence of dementia (521 diagnosed cases) using a 25-year follow-up. Here we report higher dementia risk associated with a sleep duration of six hours or less at age 50 and 60, compared with a normal (7 h) sleep duration, although this was imprecisely estimated for sleep duration at age 70 (hazard ratios (HR) 1.22 (95% confidence interval 1.01–1.48), 1.37 (1.10–1.72), and 1.24 (0.98–1.57), respectively). Persistent short sleep duration at age 50, 60, and 70 compared to persistent normal sleep duration was also associated with a 30% increased dementia risk independently of sociodemographic, behavioural, cardiometabolic, and mental health factors. These findings suggest that short sleep duration in midlife is associated with an increased risk of late-onset dementia. Sleep dysregulation has been linked to dementia, but it is unknown whether sleep duration earlier in life is associated with dementia risk. Here, the authors show higher dementia risk associated with short sleep duration (six hours or less) in a longitudinal study of middle and older age adults.

Kim H.R., Lee H., Seong Y., Lee E., Jung H., Park Y.R., Jang I.

Disability, which is considered a health-related condition, increases care demands and socioeconomic burdens for both families and communities. To confirm the trend of dynamic longitudinal changes in disability, this study aims to explore how disability is divided by the trajectory method, which deals with time-sequenced data. Additionally, this study examines the differences in demographics, geriatric conditions, and time spent at home among the trajectory groups in community-dwelling older adults. Home time is defined as the period during which the patient was not in a hospital or health care facility during their lifetime. Records of 786 community-dwelling older participants were analyzed from the Aging Study of PyeongChang Rural Area, a population-based cohort study that took place over three years. Using 7 domains of activities of daily living and 10 domains of instrumental activities of daily living, participants were grouped into no dependency (0 disabled domain), mild (1 disabled domain), and severe (2 or more disabled domains) disability groups. The longitudinal trajectory group of disability was calculated as a trajectory method. Three distinct trajectory groups were calculated over time: a relatively-stable group (78.5%; n = 617), a gradually-aggravated group (16.0%; n = 126), and a rapidly-deteriorated group (5.5%; n = 43). The average age of 786 participants was 73.3 years (SD: 5.8), and the percentage of female was 52.7%. It was found that 78.5% of patients showed relatively no dependence and 5.5% of older adults in a rural area showed severe dependence. Through applying the trajectory method, it was shown that the Short Physical Performance Battery (SPPB) score was 10.2 points in the relatively-stable group and 3.1 points in the rapidly-deteriorating group by the 3rd year. Additionally, by the trajectory method, the rate of decrease in home time was 3.33% in the rapidly-deteriorated group compared to the relatively-stable group. This study shows the difference in demographics and geriatric conditions (such as SPPB) through the examination of longitudinal trajectory groups of disability in community-dwelling older adults. Significant differences were also found in the amount of home time among the trajectory groups.

Ma Y., Liang L., Zheng F., Shi L., Zhong B., Xie W.

Importance An association between sleep duration and the trajectory of cognitive decline has not been conclusively demonstrated. Objective To investigate the association between sleep duration and cognitive decline by a pooled analysis of 2 nationally representative aging cohorts. Design, Setting, and Participants A pooled cohort study using data from waves 4 to 8 (2008-2009 to 2016-2017) in the English Longitudinal Study of Ageing and waves 1 to 3 (2011 to 2015) in the China Health and Retirement Longitudinal Study in a population-based setting. Participants were 2 randomly enrolled cohorts comprising 28 756 individuals living in England who were 50 years or older and those living in China who were 45 years or older. Exposure Self-reported sleep duration per night according to face-to-face interviews. Main Outcomes and Measures Global cognitivezscores were calculated according to immediate and delayed recall test, an animal fluency test, the serial sevens test, an intersecting pentagon copying test, and a date orientation test. Results Data were analyzed from 20 065 participants, including 9254 from the English Longitudinal Study of Ageing (mean [SD] age, 64.6 [9.8] years; 55.9% [5174 of 9254] women; median follow-up duration, 8 [interquartile range, 6-8] years) and 10 811 from the China Health and Retirement Longitudinal Study (mean [SD] age, 57.8 [9.0] years; 50.2% [5425 of 10 811] men; median follow-up duration, 4 [interquartile range, 4-4] years). During 100 000 person-years of follow-up, global cognitivezscores in individuals with 4 hours or less (pooled β = −0.022; 95% CI, −0.035 to −0.009 SD per year;P = .001) and 10 hours or more (pooled β = −0.033; 95% CI, −0.054 to −0.011 SD per year;P = .003) of sleep per night declined faster than in the reference group (7 hours per night) after adjusting for a number of covariates. An inverted U-shaped association between sleep duration and global cognitive decline was also observed. Conclusions and Relevance In this pooled cohort study, an inverted U-shaped association between sleep duration and global cognitive decline was found, indicating that cognitive function should be monitored in individuals with insufficient (≤4 hours per night) or excessive (≥10 hours per night) sleep duration. Future studies are needed to examine the mechanisms of the association between sleep duration and cognitive decline.

Titova O.E., Michaëlsson K., Larsson S.C.

Background and Purpose: Studies of sleep duration in relation to specific types of stroke are scarce. Moreover, the results are inconclusive and causality remains unclear. Our objective was to investigate whether sleep duration is associated with risk of stroke and its types using observational and Mendelian randomization designs. Methods: The prospective study included 79 881 women and men (45–79 years of age) who were followed up for incident stroke or death over a mean follow-up of 14.6 years (1 164 646 person-years) through linkage to Swedish Registers. For the Mendelian randomization study, single-nucleotide polymorphisms associated with sleep duration were identified from a genome-wide association study. Summarized data for genetic associations with stroke were obtained from publicly available data of the MEGASTROKE and the International Stroke Genetics Consortia. Results: Compared with normal sleep duration, long sleep (≥9 hours per day) was associated with increased risk of total and ischemic stroke (hazard ratios [95% CI], 1.12 [1.03–1.22] and 1.14 [1.03–1.24], respectively), whereas short sleep (<7 h/d) was linked to higher risk of intracerebral hemorrhage (hazard ratio [95% CI], 1.21 [1.03–1.41]). The 2-sample Mendelian randomization analysis supported no causal association of short or long sleep duration with ischemic stroke as a whole. Conclusions: In a prospective study, long sleep duration was associated with increased risk of total and ischemic stroke, whereas short sleep was linked to increased risk of intracerebral hemorrhage. However, the Mendelian randomization analysis did not show a significant detrimental effect of short or long sleep duration on the risk of total stroke or stroke types.

Holding B.C., Sundelin T., Schiller H., Åkerstedt T., Kecklund G., Axelsson J.

Significance We observe that a change from very alert to very sleepy can decrease social contact by approximately 70%. We also reveal moderators of this effect, such as time of day. This finding provides a perspective on, and possible mechanism as to, why sleep disturbances and other causes of sleepiness (such as medicine side effects or shift work), are associated with poorer health outcomes. It is especially urgent to understand the causes of decreased social activity, as rates of social isolation and loneliness are reported to be rising, as are rates of sleep disturbance. The results provide directions for future research, for example regarding whether interventions to alleviate sleepiness can be an effective way to improve both short- and long-term well-being.

Chen L., Woo J., Assantachai P., Auyeung T., Chou M., Iijima K., Jang H.C., Kang L., Kim M., Kim S., Kojima T., Kuzuya M., Lee J.S., Lee S.Y., Lee W., et. al.

Clinical and research interest in sarcopenia has burgeoned internationally, Asia included. The Asian Working Group for Sarcopenia (AWGS) 2014 consensus defined sarcopenia as “age-related loss of muscle mass, plus low muscle strength, and/or low physical performance” and specified cutoffs for each diagnostic component; research in Asia consequently flourished, prompting this update. AWGS 2019 retains the previous definition of sarcopenia but revises the diagnostic algorithm, protocols, and some criteria: low muscle strength is defined as handgrip strength

Pereira C., Bravo J., Raimundo A., Tomas‐Carus P., Mendes F., Baptista F.

Background Falls and fall-related injuries along with fear of falling (FoF) seem to restrict activities of daily living (ADL), resulting in physical dependence. However, it is still unclear how falls and related injuries or FoF by themselves explain general and specific ADL dependence. Objectives To investigate the relationships between falls and related injuries, FoF and physical dependence on ADL in community-dwelling older adults, controlling for age, gender, physical activity and physical fitness as confounders. Methods This cross-sectional descriptive study assessed 588 community-dwelling older adults. Falls and fall-related injuries, ADL dependence on basic, instrumental and advanced activities, FoF, demographic characteristics and health conditions were assessed through a questionnaire. Physical activity was measured through the International Physical Activity Questionnaire. Physical fitness was assessed by the Senior Fitness Test and the Fullerton Advanced Balance Scale. Body composition was measured through bioimpedance. Results Severe injuries occurrence increased the likelihood of moderate and high physical dependence by 3 and 6 times, while FoF increased this likelihood by 3 and 7 times, respectively. Also, the occurrence of previous falls, resulting in severe injuries, increased the likelihood of dependence in two instrumental ADL (3 and 4 times), while FoF increased this likelihood in numerous basic, instrumental and advanced ADL (2-3 times). The FoF was shown to explain overall physical functioning dependence, by itself, representing a constraint on the performance of most basic, instrumental and advanced ADL. Conclusion The FoF showed to be a greater threat to ADL dependence than falls and related injuries. Assessment guidelines for older adults living in the community should include the FoF in clinical evaluation. Implications for practice Understand the isolated interplay of FoF and previous falls and injuries on ADL dependence among older adults allows healthcare professionals to perform more accurate clinical evaluations and develop more successful interventions to prevent further dependence.

Wang D.X., Yao J., Zirek Y., Reijnierse E.M., Maier A.B.

Background Activities of daily living (ADLs) and instrumental activities of daily living (IADLs) are essential for independent living and are predictors of morbidity and mortality in older populations. Older adults who are dependent in ADLs and IADLs are also more likely to have poor muscle measures defined as low muscle mass, muscle strength, and physical performance, which further limit their ability to perform activities. The aim of this systematic review and meta-analysis was to determine if muscle measures are predictive of ADL and IADL in older populations. Methods A systematic search was conducted using four databases (MEDLINE, EMBASE, Cochrane, and CINAHL) from date of inception to 7 June 2018. Longitudinal cohorts were included that reported baseline muscle measures defined by muscle mass, muscle strength, and physical performance in conjunction with prospective ADL or IADL in participants aged 65 years and older at follow-up. Meta-analyses were conducted using a random effect model. Results Of the 7760 articles screened, 83 articles were included for the systematic review and involved a total of 108 428 (54.8% female) participants with a follow-up duration ranging from 11 days to 25 years. Low muscle mass was positively associated with ADL dependency in 5/9 articles and 5/5 for IADL dependency. Low muscle strength was associated with ADL dependency in 22/34 articles and IADL dependency in 8/9 articles. Low physical performance was associated with ADL dependency in 37/49 articles and with IADL dependency in 9/11 articles. Forty-five articles were pooled into the meta-analyses, 36 reported ADL, 11 reported IADL, and 2 reported ADL and IADL as a composite outcome. Low muscle mass was associated with worsening ADL (pooled odds ratio (95% confidence interval) 3.19 (1.29-7.92)) and worsening IADL (1.28 (1.02-1.61)). Low handgrip strength was associated with both worsening ADL and IADL (1.51 (1.34-1.70); 1.59 (1.04-2.31) respectively). Low scores on the short physical performance battery and gait speed were associated with worsening ADL (3.49 (2.47-4.92); 2.33 (1.58-3.44) respectively) and IADL (3.09 (1.06-8.98); 1.93 (1.69-2.21) respectively). Low one leg balance (2.74 (1.31-5.72)), timed up and go (3.41 (1.86-6.28)), and chair stand test time (1.90 (1.63-2.21)) were associated with worsening ADL. Conclusions Muscle measures at baseline are predictors of future ADL and IADL dependence in the older adult population.

Wang C., Bangdiwala S.I., Rangarajan S., Lear S.A., AlHabib K.F., Mohan V., Teo K., Poirier P., TSE L.A., Liu Z., Rosengren A., Kumar R., Lopez-Jaramillo P., Yusoff K., Monsef N., et. al.

Abstract Aims To investigate the association of estimated total daily sleep duration and daytime nap duration with deaths and major cardiovascular events. Methods and results We estimated the durations of total daily sleep and daytime naps based on the amount of time in bed and self-reported napping time and examined the associations between them and the composite outcome of deaths and major cardiovascular events in 116 632 participants from seven regions. After a median follow-up of 7.8 years, we recorded 4381 deaths and 4365 major cardiovascular events. It showed both shorter (≤6 h/day) and longer (&gt;8 h/day) estimated total sleep durations were associated with an increased risk of the composite outcome when adjusted for age and sex. After adjustment for demographic characteristics, lifestyle behaviours and health status, a J-shaped association was observed. Compared with sleeping 6–8 h/day, those who slept ≤6 h/day had a non-significant trend for increased risk of the composite outcome [hazard ratio (HR), 1.09; 95% confidence interval, 0.99–1.20]. As estimated sleep duration increased, we also noticed a significant trend for a greater risk of the composite outcome [HR of 1.05 (0.99–1.12), 1.17 (1.09–1.25), and 1.41 (1.30–1.53) for 8–9 h/day, 9–10 h/day, and &gt;10 h/day, P  trend &lt; 0.0001, respectively]. The results were similar for each of all-cause mortality and major cardiovascular events. Daytime nap duration was associated with an increased risk of the composite events in those with over 6 h of nocturnal sleep duration, but not in shorter nocturnal sleepers (≤6 h). Conclusion Estimated total sleep duration of 6–8 h per day is associated with the lowest risk of deaths and major cardiovascular events. Daytime napping is associated with increased risks of major cardiovascular events and deaths in those with &gt;6 h of nighttime sleep but not in those sleeping ≤6 h/night.