Effects of exercise on brain activity during walking in older adults: a randomized controlled trial.

BACKGROUND: Physical activity may preserve neuronal plasticity, increase synapse formation, and cause the release of hormonal factors that promote neurogenesis and neuronal function. Previous studies have reported enhanced neurocognitive function following exercise training. However, the specific cortical regions activated during exercise training remain largely undefined. In this study, we quantitatively and objectively evaluated the effects of exercise on brain activity during walking in healthy older adults. METHODS: A total of 24 elderly women (75-83 years old) were randomly allocated to either an intervention group or a control group. Those in the intervention group attended 3 months of biweekly 90-min sessions focused on aerobic exercise, strength training, and physical therapy. We monitored changes in regional cerebral glucose metabolism during walking in both groups using positron emission tomography (PET) and [18F]fluorodeoxyglucose (FDG). RESULTS: All subjects completed the 3-month experiment and the adherence to the exercise program was 100%. Compared with the control group, the intervention group showed a significantly greater step length in the right foot after 3 months of physical activity. The FDG-PET assessment revealed a significant post-intervention increase in regional glucose metabolism in the left posterior entorhinal cortex, left superior temporal gyrus, and right superior temporopolar area in the intervention group. Interestingly, the control group showed a relative increase in regional glucose metabolism in the left premotor and supplemental motor areas, left and right somatosensory association cortex, and right primary visual cortex after the 3-month period. We found no significant differences in FDG uptake between the intervention and control groups before vs. after the intervention. CONCLUSION: Exercise training increased activity in specific brain regions, such as the precuneus and entorhinal cortices, which play an important role in episodic and spatial memory. Further investigation is required to confirm whether alterations in glucose metabolism within these regions during walking directly promote physical and cognitive performance. TRIAL REGISTRATION: UMIN-CTR ( UMIN000021829 ). Retrospectively registered 10 April 2016.

Factors associated with the level of disability in elderly adults based on the Japanese long-term care insurance system.

AIM: The aim of this study was to identify factors associated with the level of disability in elderly adults based on the Japanese long-term care insurance system. METHODS: The participants included 3,198 frail elderly subjects (mean age: 82.0±6.45). The slightly disabled group, with a support level in the long-term care insurance system, comprised 1,129 elderly adults, and the moderately disabled group, with a care level of 1 or 2 in the long-term care insurance system, comprised 2,208 elderly adults who received day-care services. The following parameters were evaluated: grip strength, chair stand test 5-times (CST), one-leg standing with eyes open (OLS), timed "up & go" (TUG), walking speed, the mental status questionnaire (MSQ) score and functional independence measures (FIM). The participants were categorized into two groups based on the 13 motor subscales of the FIM (FIM-M): the activity of daily living (ADL) independent group, who scored 6 points or higher on all ADL measurements, and the ADL care need group, who scored 5 points or under on at least one item in all ADL measurements. A multiple logistic regression analysis was used to examine the relationships between the long-term care insurance level and the potential correlates. RESULTS: The multiple logistic regression model indicated that gender, grip strength and the MSQ and FIM-M scores were significantly associated with the long-term care insurance level (p<0.05). The FIM-M score exhibited a particularly strong correlation with the type of long-term care required (odds ratio: 2.47, 95% confidence interval: 1.89-3.24). CONCLUSIONS: The Japanese long-term care insurance level is associated with physical performance, the cognitive function and the ability to perform ADL's. These results suggest that comprehensive assessments are useful for understanding the impact of the long-term care insurance level in elderly adults.

Performance-based assessments and demand for personal care in older Japanese people: a cross-sectional study.

OBJECTIVES: To identify appropriate clinical tests for determining the demand for personal care in older Japanese people. DESIGN: Cross-sectional observation study. SETTING: Obu Study of Health Promotion for the Elderly (Obu, Aichi) and Tsukui Ordered Useful Care for Health (241 day-care centres) cohorts in Japan. PARTICIPANTS: A total of 10 351 individuals aged 65 years or older (6791 with personal care and 3560 without personal care) participated in the study. MEASURES: Physical performance tests included grip strength, the chair stand test, walking speed at a comfortable pace, and the timed up-and-go test. Personal care was defined as participants who had been certified in the national social long-term care insurance in Japan. RESULTS: Individuals who received personal care showed a significantly poorer performance than those without personal care for all physical performance tests (p<0.001). Gait speed was the most useful of the physical performance tests to determine the demand for personal care (receiver operating characteristic curve statistics: men, 0.92; women, 0.94; sensitivity: men, 86; women, 90; specificity: men, 85; women, 85). After adjustment for age, sex, cognitive impairment and other physical tests, all physical performance tests were individually associated with the demand for personal care. A slow gait speed (<1 m/s) was more strongly correlated with the demand for personal care than other performance measures (gait speed OR: 5.9; 95% CI: 5.0 to 6.9). CONCLUSIONS: Clinical tests of physical performance are associated with the demand for personal care in older people. Preventive strategies to maintain physical independence may be required in older adults who show a gait speed slower than 1 m/s. Further research is necessary to confirm these preliminary results.

Gait adaptability and brain activity during unaccustomed treadmill walking in healthy elderly females.

This study evaluated brain activity during unaccustomed treadmill walking using positron emission tomography (PET) and [(18)F]fluorodeoxyglucose. Twenty-four healthy elderly females (75-82 years) participated in this study. Two PET scans were performed after 25 min of rest and after walking for 25 min at 2.0 km/h on a treadmill. Participants were divided into low and high step-length variability groups according to the median coefficient of variation in step length during treadmill walking. We compared the regional changes in brain glucose metabolism between the two groups. The most prominent relative activations during treadmill walking compared to rest in both groups were found in the primary sensorimotor areas, occipital lobe, and anterior and posterior lobe of the cerebellum. The high step-length variability group showed significant relative deactivations in the frontal lobe and the inferior temporal gyrus during treadmill walking. There was a significant relative activation of the primary sensorimotor area in the low step-length variability group compared to the high step-length variability group (P = 0.022). Compared to the low step-length variability group, the high step-length variability group exhibited a greater relative deactivation in the white matter of the middle and superior temporal gyrus (P = 0.032) and hippocampus (P = 0.034) during treadmill walking compared to resting. These results suggest that activation of the primary sensorimotor area, prefrontal area, and temporal lobe, especially the hippocampus, is associated with gait adaptability during unaccustomed treadmill walking.

Relationship between subjective fall risk assessment and falls and fall-related fractures in frail elderly people.

BACKGROUND: Objective measurements can be used to identify people with risks of falls, but many frail elderly adults cannot complete physical performance tests. The study examined the relationship between a subjective risk rating of specific tasks (SRRST) to screen for fall risks and falls and fall-related fractures in frail elderly people. METHODS: The SRRST was investigated in 5,062 individuals aged 65 years or older who were utilized day-care services. The SRRST comprised 7 dichotomous questions to screen for fall risks during movements and behaviours such as walking, transferring, and wandering. The history of falls and fall-related fractures during the previous year was reported by participants or determined from an interview with the participant's family and care staff. RESULTS: All SRRST items showed significant differences between the participants with and without falls and fall-related fractures. In multiple logistic regression analysis adjusted for age, sex, diseases, and behavioural variables, the SRRST score was independently associated with history of falls and fractures. Odds ratios for those in the high-risk SRRST group (≥ 5 points) compared with the no risk SRRST group (0 point) were 6.15 (p < 0.01) for a single fall, 15.04 (p < 0.01) for recurrent falls, and 5.05 (p < 0.01) for fall-related fractures. The results remained essentially unchanged in subgroup analysis accounting for locomotion status. CONCLUSION: These results suggest that subjective ratings by care staff can be utilized to determine the risks of falls and fall-related fractures in the frail elderly, however, these preliminary results require confirmation in further prospective research.

Physical factors underlying the association between lower walking performance and falls in older people: a structural equation model.

The purpose of this study was to determine the interrelationships between lower limb muscle performance, balance, gait and falls in older people using structural equation modeling. Study participants were two hundred and thirteen people aged 65 years and older (mean age, 80.0 ± 7.1 years), who used day-care services in Japan. The outcome measures were the history of falls three months retrospectively and physical risk factors for falling, including performance in the chair stand test (CST), one-leg standing test (OLS), tandem walk test, 6m walking time, and the timed up-and-go (TUG) test. Thirty-nine (18.3%) of the 213 participants had fallen at least one or more times during the preceding 3 months. The fall group had significantly slower 6m walking speed and took significantly longer to undertake the TUG test than the non-fall group. In a structural equation model, performance in the CST contributed significantly to gait function, and low gait function was significantly and directly associated with falls in older people. This suggests that task-specific strength exercise as well as general mobility retraining should be important components of exercise programs designed to reduce falls in older people.

Which neuromuscular or cognitive test is the optimal screening tool to predict falls in frail community-dwelling older people?

BACKGROUND: The use of falls risk screening tools may aid in targeting fall prevention interventions in older individuals most likely to benefit. OBJECTIVE: To determine the optimal physical or cognitive test to screen for falls risk in frail older people. METHODS: This prospective cohort study involved recruitment from 213 day-care centers in Japan. The feasibility study included 3,340 ambulatory individuals aged 65 years or older enrolled in the Tsukui Ordered Useful Care for Health (TOUCH) program. The external validation study included a subsample of 455 individuals who completed all tests. Physical tests included grip strength (GS), chair stand test (CST), one-leg standing test (OLS), functional reach test (FRT), tandem walking test (TWT), 6-meter walking speed at a comfortable pace (CWS) and at maximum pace (MWS), and timed up-and-go test (TUG). The mental status questionnaire (MSQ) was used to measure cognitive function. The incidence of falls during 1 year was investigated by self-report or an interview with the participant's family and care staff. RESULTS: The most practicable tests were the GS and MSQ, which could be administered to more than 90% of the participants regardless of the activities of daily living status. The FRT and TWT had lower feasibility than other lower limb function tests. During the 1-year retrospective analysis of falls, 99 (21.8%) of the 455 validation study participants had fallen at least once. Fallers showed significantly poorer performance than non-fallers in the OLS (p = 0.003), TWT (p = 0.001), CWS (p = 0.013), MWS (p = 0.007), and TUG (p = 0.011). The OLS, CWS, and MWS remained significantly associated with falls when performance cut-points were determined. Logistic regression analysis revealed that the TWT was a significant and independent, yet weak predictor of falls. A weighting system which considered feasibility and validity scored the CWS (at a cut-point of 0.7 m/s) as the best test to predict risk of falls. CONCLUSION: Clinical tests of neuromuscular function can predict risk of falls in frail older people. When feasibility and validity were considered, the CWS was the best test for use as a screening tool in frail older people, however, these preliminary results require confirmation in further research.

[Incidence of falls and fractures in disabled elderly people utilizing long-term care insurance].

AIM: To investigate the incidence of falls and fall-related fractures in disabled elderly people utilizing long-term care insurance, and influence of gender, age, disabled level is examined. METHODS: Subjects were 8,335 elderly people (mean age, 82.2+/-7.4 years). Falls and fractures were investigated retrospectively for the one year study period either via a self-report questionnaire, or via care workers and/or family members when the subjects had cognitive impairments. The care workers gave are a free description about for the fall that had occurred when using the facilities. RESULTS: Men showed significantly higher rate of falls (26.8%) than women (24.6%). In women, there was a significant difference in fall rates between the severely disabled group (26.4%) and the moderately disabled group (23.5%). Women showed a significantly higher rate of fractures (12.2%) than that of men (4.5%). In relationship between fall-related fractures and potential correlates, there was a significant relation between women and the fall-related fractures [OR 2.5, 95%CI 1.7-3.6]. The severely disabled group showed a significantly higher rate of falls in the toilet, on the other hand, the moderately disabled group showed significantly higher rate of falls during exercise and recreation or standing. CONCLUSION: The rate of falls in women was lower than men in this study population. The result may be affected by the lower proportion of women in the moderately disabled group compared with men. Only gender was significantly associated with the incidence of fall-related fractures in disabled elderly people.