The relationship between acceleration in sit-to-stand and falls in community-dwelling older adults: cross-sectional study

[Purpose] This study aimed to determine the relationship between acceleration parameters in the sit-to-stand (STS) movement and falls, and the strength of the association between acceleration in STS movements and falls in older adults. [Participants and Methods] In total, 330 older adults were included. Four acceleration parameters were measured in STS movement: maximum acceleration (MA), velocity (MV), power (MP), and stand-up time (ST). For the conventional STS tests, 5 times STS test (5xSTS) and ground reaction force (maximal rate of force development per body weight: RFD/w, peak reaction force per body weight: F/w, chair-rise time: T) were measured. Poisson regression analysis adjusted for confounding factors was used. [Results] In the model adjusted for confounders, significant associations were observed among MV (Prevalence ratio (PR): 0.75; 95% confidence interval (CI): 0.58-0.98), MP (PR: 0.67; 95% Cl: 0.68-0.93), RFD/w (PR: 0.70; 95% Cl: 0.56-0.87), and T (PR: 1.14; 95% Cl: 1.05-1.24). [Conclusion] Among the acceleration parameters, MP was most strongly associated with falls and was considered the most useful parameter for evaluation. In addition, comparisons with the conventional chair rise tests suggested that MP was stronger than the 5xSTS test and may be equally related to the RFD/w.

Relationship between Acceleration in a Sit-To-Stand Movement and Physical Function in Older Adults

Acceleration parameters in sit-to-stand (STS) movements are useful for measuring lower-limb function in older adults. The purpose of this study was to examine the relationship between acceleration in STS movements and physical function and the test-retest reliability of acceleration parameters in older adults. We performed cross-sectional analyses on 244 older adults including 107 men (mean age: 77.4 ± 4.7) and 137 women (mean age: 75.6 ± 5.3). Four acceleration parameters were measured in STS movements: maximum acceleration (MA), maximum velocity (MV), maximum power (MP), and stand-up time (ST). Good intraclass correlation coefficients (ICC > 0.70) were observed for all parameters. For the acceleration parameters, MA, MV, and MP were relatively strongly associated with the 5-time STS test (men: r = -0.36~-0.47; women: r = -0.37~-0.45) and the timed up and go test (men: r = -0.39~0.47, women: r = -0.43~-0.51): MP was also strongly associated with grip strength (men: r = 0.48, women: r = 0.43). All acceleration parameters were poorer in participants reporting mobility limitations than in those reporting no mobility limitations. These findings support the usefulness of sensor-based STS measurement. The system is expected to be useful in various settings where care prevention is addressed.

Segmental extracellular-to-intracellular water resistance ratio and physical function in older adults

OBJECTIVES

This study aimed to investigate the association between whole-body (WB), arm, and leg extracellular-to-intracellular water resistance (Recw/Ricw) ratios and various physical functions of each segment and muscle mass using segmental multifrequency bioelectrical impedance analysis.

METHODS

In total, 988 community-dwelling older adults were included in the analysis. Physical function was assessed using hand grip, 5-repetition sit-to-stand, 5-m habitual walk, Timed Up and Go, and single-leg balance with eyes open tests. Each segmental Recw/Ricw ratio and muscle mass were assessed at 5 and 250 kHz resistances using a segmental multifrequency bioelectrical impedance analysis device. Pearson's correlation between the segmental Recw/Ricw ratio and muscle mass and physical function was calculated, and the difference in correlation coefficients was tested using Bonferroni correction. Multiple linear regression analysis was conducted using physical function as the dependent variable and the segmental Recw/Ricw ratio as the independent variable, adjusting for sex, age, body mass index, and segmental muscle mass.

RESULTS

WB and leg Recw/Ricw ratios were significantly positively correlated with good hand grip performance, gait speed, mobility, balance, and standing power (p < 0.05), after adjusting for sex, age, body mass index, and muscle mass. Furthermore, the leg Recw/Ricw ratio was positively associated with lower extremity physical function compared with WB and arm Recw/Ricw ratios and muscle mass (p < 0.01). Conversely, WB muscle mass was more strongly related to grip strength than WB, arm, and leg Recw/Ricw ratios (p < 0.01).

CONCLUSIONS

The Recw/Ricw ratio is useful for identifying older adults with worse physical function. The Recw/Ricw ratio allows for easy and timely screening of older adults with worse physical function in clinical settings.

Association of 24-h movement behaviors with phase angle in community-dwelling older adults: a compositional data analysis

BACKGROUND

Phase angle (PhA) is an indicator of cellular conditions. Recent studies have suggested that PhA supports healthy aging. Identifying modifiable lifestyle factors for PhA is important. The associations of PhA in 24-h movement behaviors, including physical activity (PA), sedentary behavior (SB), and sleep, have not been studied in older adults.

OBJECTIVES

We investigated the cross-sectional associations between 24-h movement behaviors and PhA in community-dwelling older adults while appropriately considering the co-dependent nature of daily time use using compositional data analysis.

METHODS

The participants were 113 healthy older adults. PhA was measured using a bioelectrical impedance device. Time spent in light-intensity PA (LPA), moderate- to vigorous-intensity PA (MVPA), and SB was measured using a tri-axial accelerometer. Sleep duration information was self-reported in a questionnaire. Compositional multiple linear regression and compositional isotemporal substitution were performed to examine the associations of 24-h movement behaviors with PhA and hypothetical time reallocation in movement behaviors with PhA, respectively.

RESULTS

Even after adjusting for potential confounders, relative to other behaviors more time spent in MVPA was significantly associated with higher PhA (p < 0.001). The 30 min/day of time reallocation from the other behaviors (SB, LPA, and sleep) to MVPA was predicted to be 0.12 higher PhA (corresponding to 2.3% increase; 95% CI 0.01, 0.24).

CONCLUSIONS

Our results suggest that increasing or maintaining the daily time spent in MVPA is important for managing PhA in older adults, regardless of the other behaviors time consumed instead.

Evaluation of Cognitive and Physical Function Among Older Adults by Their Physical Activity: A Cross-Sectional Kasama Study, Japan

BACKGROUND

The amyloid-β1-42 (Aβ42) level is a biomarker that is widely used to evaluate individual cognitive dysfunction early in neurodegenerative diseases, as well as differentiate between normal cognitive function, mild cognitive impairment, Alzheimer's disease, and vascular cognitive impairment.

OBJECTIVE

Our cross-sectional study evaluated the association between daily exercise and physical and cognitive function and Aβ42 levels among a subsample of 325 older adults from the Kasama Study.

METHODS

Participants (age: 74.5 [range 65-90] years) were classified into three exercise groups: the dual-task (DEG, n = 128), single-task (SEG, n = 122), and non-exercise (NEG, n = 75) groups. The main outcomes were the plasma Aβ42 levels and the scores of the five cognitive (5-COG) tests and five cognition-related physical function (5-PHYS) tests.

RESULTS

The Aβ42 levels and 5-COG and 5-PHYS scores were higher in the SEG and DEG than in the NEG. The Aβ42 levels were higher in the DEG than in the NEG (p = 0.008).

CONCLUSIONS

Physical activities such as regular exercise may benefit older adults, improving their cognitive and physical function.

[Changes in the physical fitness of elderly people in the COVID-19 pandemic: An examination using performance tests]

OBJECTIVE

This study aimed to ascertain the physical-fitness trends among community-dwelling older adults using performance testing. The results of the evaluation conducted during the COVID-19 pandemic were compared to data from the pre-pandemic period.

METHODS

A total of 240 community-dwelling older adults who participated in a health checkup program from 2016-2020 underwent the following tests: grip strength (upper limb muscle), single-leg balance with eyes open (static balance), sit-and-reach test (flexibility), timed up-and-go test (TUG, functional mobility), 5 meter habitual walk (walking ability), and hand working with pegboard (hand dexterity). Linear mixed effect models were applied to the hierarchical dataset: repeated data (Level 1), pre-pandemic (2016-2019), pandemic (2019-2020) (Level 2), and individuals (Level 3). Fixed effects and interactions were estimated for the survey year (Level 1), and between the survey year and pre- and post-pandemic (Level 2), with the range of decline set measured in terms of its standardized partial regression coefficient, "B," from 2019-2020.

RESULTS

The items for which significant cross-level interactions were identified. In males, the following items showed significant cross-level interactions: sit and reach test (B=-2.56, 95% CI: -4.45--0.66 cm), TUG (+0.39, 0.21-0.56 sec) and 5 meter habitual walk (+0.15, 0.04-0.27 sec). In females items except single-leg balance with eyes open showed significant cross-level interactions: grip strength (-0.58, -1.11--0.05 kg), sit-and-reach test (-3.53, -5.11--1.95 cm), TUG (+0.15, 0.03-0.27 sec), for 5 meter habitual walk (+0.14, 0.04-0.24 sec), and hand working with pegboard (+0.89, 0.28-1.51 sec).

CONCLUSION

In both males and females, a significant deterioration in flexibility and mobility movement ability was observed in 2019-2020. In addition, upper limb muscle strength and hand dexterity movement deteriorated in females.

Pre-frailty associated with traffic crashes in Japanese community-dwelling older drivers

Objectives: Frailty might be useful to identify older drivers who are at risk for traffic crashes. We aim to examine the association between pre-frailty/frailty defined by the Kihon Checklist (KCL) and the involvement of traffic crashes and clarify whether some domains of the KCL are associated with traffic crashes.Methods: This cross-sectional study analyzed data from 2,208 Japanese community-dwelling older drivers aged ≥ 65 years in Kasama City, who participated in our postal survey in November 2019. A self-reported history of traffic crashes was used to divide participants into non-crash-involved and crash-involved groups.Results: A total of 192 (8.7%) participants had been involved in traffic crashes in the past year. The crash-involved group was found to have gained more body mass index, driven more frequently, and scored higher on the total KCL score than the non-crash-involved group (all P < .05). Binary logistic regression analyses showed that after adjusting for age, sex, education, driving frequency, and driving distance, pre-frailty (OR = 1.52, 95% CI: 1.10-2.10) was more significantly associated with traffic crashes as compared to robustness. Those who had impairment in the oral domain (OR = 1.57, 95% CI: 1.09-2.27) and memory domain (OR = 1.38, 95% CI: 1.01-1.90) were also more likely to be involved in traffic crashes.Conclusion: The results suggest that identifying pre-frailty may play an important pole in crash prevention. Additionally, more attention should be given to older drivers with oral dysfunction and cognitive impairment.

Combined effect of daily physical activity and social relationships on sleep disorder among older adults: cross-sectional and longitudinal study based on data from the Kasama study

Background

This study investigated whether daily physical activity of older adults, combined with social relationships, is associated with the risk of sleep disorder. Further, it determined whether a high level of one variable with a low level of the other, leads to a significantly lower risk of sleep disorder than low levels of both.

Methods

The sample comprised 1339 community-dwelling older Japanese adults: 988 in Study 1 and 351 in Study 2. The level of daily physical activity and range of social relationships were assessed using the Physical Activity Scale for the Elderly and the Lubben Social Network Scale, respectively. The Pittsburgh Sleep Quality Index was used to assess sleep disorder. To test the combined relationships and effects in Studies 1 and 2, the medians for the respective scores of each of the following four groups that the participants were categorized into, were calculated: (1) low activity group with low social relationships, (2) low activity group with high social relationships, (3) high activity group with low social relationships, and (4) high activity group with high social relationships. After adjusting for potential confounders, a logistic regression analysis was conducted in Study 1. After adjusting for potential confounders, a Cox proportional hazards regression analysis was conducted in Study 2.

Results

Study 1 revealed that the high activity group with high social relationships showed a significantly lower risk of sleep disorder (ORs: 0.585, 95% CI: 0.404–0.847) than the low activity group with low social relationships. Study 2 also revealed that the high activity group with high social relationships showed a significantly lower prevalence of sleep disorder (HRs: 0.564, 95% CI: 0.327–0.974) than the low activity group with low social relationships.

Conclusions

Our findings suggest that for older adults with high social relationships, being physically active is favorably associated with sleep quality. However, a high level of one variable with a low level of the other has not been confirmed in improving sleep quality among older adults.

Mediating role of instrumental activities of daily living ability on cognitive function of older adults living alone: A 4-year longitudinal study from the Kasama study

The aim of this study was to clarify the effect of living alone on the cognitive function of older people and the mediating effect of instrumental activities of daily living (IADL) ability.The data for a final sample of 3276 participants aged 65 years and above who did not require long-term care at the baseline were used from a 4-year prospective cohort study conducted in Kasama City, Japan. Demographic data including age, sex, and depression at baseline were used as covariates. The Kihon checklist evaluated the IADL ability at baseline and cognitive function at follow-up. The characteristics of those living alone and with others were compared using the student t test and χ2 test. The effect of living alone on cognitive function was analyzed using logistic regression analysis. Mediation analyses determined the mediating effects of IADL.A total of 325 participants were living alone; they were significantly older than those living with others, more likely to be female, not provide emotional support, and have low physical function, more severe depression, and lower IADL disability. Living alone had a significantly lower risk of cognitive decline at follow-up than living with others. The mediation analysis revealed that IADL disability at follow-up was significantly associated with cognitive decline. Thus, greater IADL ability decreased cognitive decline risk.Older people living alone had a significantly lower risk of cognitive decline, and cognitive function significantly mediated IADL ability. Health support for enhancing IADL abilities may help older people living alone maintain good cognitive function.

Associations between exercising in a group and physical and cognitive functions in community-dwelling older adults: a cross-sectional study using data from the Kasama Study

[Purpose] To examine the associations of exercise habits, particularly exercising in a group, with physical and cognitive functions in community-dwelling older adults. [Participants and Methods] A total of 615 older adults participated in this cross-sectional study. We conducted three physical performance tests (grip strength, five times sit-to-stand, and 5-meter walk tests) and the Five-Cog test (attention, memory, visuospatial, language, and reasoning). We investigated exercise habits using questionnaires and classified the participants into three groups as follows: those who did not exercise (n=86), those who exercised alone (n=168), and those who exercised in a group (n=362). To clarify the associations of exercise habits with physical and cognitive functions, we used the analysis of covariance with adjustment for potential confounders. [Results] The participants who exercised in a group had better lower limb strength than those who exercised alone and better scores for all the variables than the non-exercisers. Furthermore, those who exercised in a group scored significantly higher on the attention, memory, visuospatial, and overall cognitive function tests than those who exercised alone. [Conclusion] Our results highlight the importance of the social aspects associated with exercising, such as the presence of exercise peers, to improve the physical and cognitive health of older adults.

Change in hand dexterity and habitual gait speed reflects cognitive decline over time in healthy older adults: a longitudinal study

[Purpose] There is a relationship between physical and cognitive functions; therefore, impairment of physical function would mean cognitive decline. This study aimed to investigate the association between change in physical and cognitive functions. [Subjects and Methods] Participants were 169 healthy community-dwelling older adults who attend the survey after three years from baseline (mean age, 72.4 ± 4.8 years). Grip strength, one-leg standing balance, five-times-sit-to-stand test, timed up and go, 5-m habitual walk, and a peg-moving task were used to evaluate physical performance. Five cognitive function tests were used to assess attention, memory, visuospatial function, verbal fluency, and reasoning. Cognitive function was defined as the cumulative score of these tests. [Results] At baseline, five-times-sit-to-stand test, timed up and go, and hand dexterity were independently associated with cognitive function. In longitudinal analyses, changes in habitual walking speed and hand dexterity were significantly associated with change in cognitive function. [Conclusion] Deterioration of specific physical function, such as hand dexterity and walking ability, may be associated with progression of cognitive decline. Decreasing extent of daily functions, such as hand dexterity and walking ability, can be useful indices to grasp changes in cognitive function.