Hikaru Ihira

Association between a history of falls and the ability to multi-task in community-dwelling older people

Background and aims: Many older people fall when they perform tasks which require increased attention. The aim of this study was to determine differences in reaction times, during simple-, dual- and triple-task conditions requiring differing levels of motor coordination, balance control and cognitive attention, between groups of fallers and non-fallers in community-dwelling older individuals. Methods: The study involved the recruitment of 87 older individuals living at home, 57 women and 30 men aged 75 to 91 years. Reaction times, measured by pushing a handheld button as quickly as possible in response to a visual stimulus, were measured in four conditions: 1) quiet standing (simple-task); 2) counting backward during quiet standing (dual-task with cognitive demand); 3) stepping in place (dual-task with balance demand); and 4) counting backward while stepping in place (triple-task with cognitive and balance demands). Results: Twenty-nine (33.3%) participants had fallen at least once during the past year. There were no statistically significant differences in reaction times between non-fallers and fallers during any of the tasks. Reaction times were significantly longer during the dual- and triple-tasks compared with the simple-task conditions in both groups. The ratio between reaction times during dual-tasks with balance demands (stepping in place) and those in the simple-task condition were significantly related to a history of falls and showed the highest odds ratio (OR 3.16, 95% CI 1.06–9.45,p=0.04). Conclusions: Relative changes in reaction times during a dual-task with balance demands were related to a history of falls in community-dwelling older individuals. Reaction times in dual-task conditions with a balance demand were more sensitive to past falls than those during a dual-task with cognitive demands.

Physical functions, health-related outcomes, nutritional status, and blood markers in community-dwelling cancer survivors aged 75 years and older.

BACKGROUND A cancer survivor is defined as anyone who has been diagnosed with cancer, from the time of diagnosis through the rest of their life. The purpose of this study was to examine whether physical functions, health-related outcomes, nutritional status and blood markers in community-dwelling cancer survivors aged 75 years and older are different from those who do not have cancer MATERIALS AND METHODS Two hundred seventy-five participants were asked by physicians, nurses, and physical therapists, questions regarding cancer history in a face-to-face interview. Data were collected for demographic information, physical functions, such as handgrip strength, knee extension power, abdominal muscle strength, static standing balance, walking speed and the timed-up-and-go test, health-related outcomes, nutritional status, and blood markers. The measured parameters of survivor diagnosed with cancer were compared with those without a history of cancer. RESULTS Thirty-seven older adults were previously diagnosed with cancer. Female cancer survivors had lower knee extension power (p<0.05), abdominal muscle strength (p<0.05), walking speed (p<0.05), timed-up-and-go test score (p<0.05), and time to spend on walking per day (p<0.05) than older women without a history of cancer. In men, none of the measured parameters were significantly different between cancer survivors and older men with no history of cancer. CONCLUSIONS The present study shows that partial physical function of women cancer survivors aged 75 years and older differs from that in women with no history of cancer.

Subjective physical and cognitive age among community-dwelling older people aged 75 years and older: differences with chronological age and its associated factors

Objective: The aim of this cross-sectional study was to determine the associations between self-reported subjective physical and cognitive age, and actual physical and cognitive functions among community-dwelling older people aged 75 years and older. Method: The sample comprised 275 older adults aged 75–91 years. Two questions were asked regarding subjective age: ‘How old do you feel physically?’ and ‘How old do you feel cognitively?’ To assess physical functions, we measured handgrip strength, knee extension strength, standing balance and walking speed. Tests of attention, executive function, processing speed and memory were performed to assess actual cognitive function. Results: Subjective physical and cognitive age was associated with performance on all of the physical and cognitive tests, respectively (p < 0.01). We also found that older adults who reported themselves as feeling older than their chronological age had a slower walking speed and lower scores for word-list memory recall than those who did not report themselves as feeling older than their actual age. Conclusion: These findings suggest that promoting a fast walking speed and good memory function may help to maintain a younger subjective physical and cognitive age in older adults aged 75 years and older.

Associations between Serum 25-Hydroxyvitamin D Concentration and Physical Performance in Old-Old People Living in a Northern Area of Japan

Purpose: The present study aimed to investigate the relationship between serum 25-hydroxyvitamin D [25(OH) D] levels and physical performance, including muscle strength, balance, and gait speed, in older individuals living in a northern area of Japan (latitude approximately 43°north). Subjects: This was a cross-sectional analysis of 273 community-based older individuals (160 women; mean age, 80.0 years), who participated in the “Population-based and Inspiring Potential Activity for Old-old Inhabitants (PIPAOI)”study. Methods: We collected blood samples to determine serum 25(OH) D levels, and we assessed physical performance according to hand grip strength, knee extensor strength, static standing balance, hip walking distance, normal walking speed, and the results of the Timed-Up-and-Go (TUG) test. The other variables were fall experience in the year prior to the study, the Tokyo Metropolitan Institute of Gerontology Index of Competence (TMIGIC), frequency of going outdoors, sun exposure, and exercise habits. Correlations between serum 25(OH) D levels and physical performance as well as other variables were assessed using Pearson’s and Spearman’s correlation analyses. We performed an analysis of covariance (ANCOVA) controlled for age, sex, body mass index, sun exposure, and exercise habits to minimize the influence of confounders on physical performance. Results: We found significant associations between serum 25(OH) D levels and sex (rs=-0.19), bone density as measured by speed of sound in bone (r=0.16), grip strength (r=0.19), frequency of going outdoors (rs=0.16), sun exposure (rs=0.25), and TMIGIC (rs=0.15). After controlling for age, sex, BMI, sun exposure, and exercise habits, total length of the center of gravity of participants with 25(OH)D insufficiency were significantly longer than those of participants with sufficient 25(OH)D levels (p<0.05). Conclusion: Our results suggest that it is important for community-based older individuals to maintain sufficient 25(OH) D levels in order to avoid lowering physical performance.

Physical Activity during Winter in Old-Old Women Associated with Physical Performance after One Year: A Prospective Study

Background. The aim of this study was to evaluate whether the decline of physical activity during winter influences physical performances (after 1 year) in old-old women. Methods. Fifty-three Japanese women (mean age: 78.4 ± 3.2 years) participated in this study. Data of physical activity was collected by using an accelerometer at baseline and 3-month follow-up, and participants who decreased step counts in this period were defined as declining groups. We measured grip strength, knee extensor strength, total length of the center of gravity, hip walking distance, and maximum walking speed to evaluate physical performances at baseline and 1-year follow-up. Repeated-measures analysis of variance determined the difference in physical performance between declining groups and maintenance group with maintained or improved step counts. Results. Daily step counts for 22 older women (41.5%) decreased during winter. A statistically significant interaction effect between group and time was found for maximum walking speed (F(1,50) = 5.23, p = 0.03). Post hoc comparisons revealed that walking speed in the maintenance group significantly increased compared with baseline (p = 0.01); the declining group showed no significant change (p = 0.44). Conclusion. Change of physical activity during winter influences the physical performance level after 1 year in community-dwelling old-old women, particularly its effect on maximum walking speed.

The effect of gait speed and gait phase to the allocation of attention during dual task gait

[Purpose] The purpose of this study was to determine the change of allocation of attention caused by a difference in gait phase and gait speed. We also determined the relationship between attentional demand and gait automaticity change caused by the gait speed alteration. [Subjects and Methods] Ten male participated. Participants were instructed to perform the probe reaction time (RT) task during treadmill walking in four different gait speed conditions (60%, 80%, 100%, and 120% of preferred speed). Walking ratio in each gait speed conditions were calculated, and RTs and walking ratios were compared in each gait speed condition and in the single-support and double-support gait phase. [Results] RTs were significantly delayed with decline of gait speed. Walking ratio was significantly decreased in proportion of decrement of gait speed. There was no difference of gait phase between single-support and double-support phase. [Conclusion] This study showed that relationship between attentional load and deficit of gait automaticity. While gait phase didn’t influence attentional demand, and this result showed the characteristics of treadmill gait.

Structural analysis of impact of physical, cognitive and social status on the incidence of disability in community-dwelling people aged ≥75 years: Structural analysis of disability

The present study aimed to propose a structural model to explain the interaction of physical, cognitive and social domains of health status in the incidence of disability in community‐dwelling people aged ≥75 years.

Age-Related Differences in Postural Control and Attentional Cost During Tasks Performed in a One-Legged Standing Posture.

Background and Purpose:In dual-task situations, postural control is closely associated with attentional cost. Previous studies have reported age-related differences between attentional cost and postural control, but little is known about the association in conditions with a one-legged standing posture. The purpose of this study was to determine age-related differences in postural control and attentional cost while performing tasks at various difficulty levels in a one-legged standing posture. Methods:In total, 29 healthy older adults aged 64 to 78 years [15 males, 14 females, mean (SD) = 71.0 (3.8) years] and 29 healthy young adults aged 20 to 26 years [14 males, 15 females, mean (SD) = 22.5 (1.5) years] participated in this study. We measured the reaction time, trunk accelerations, and lower limb muscle activity under 3 different one-legged standing conditions—on a firm surface, on a soft surface with a urethane mat, and on a softer more unstable surface with 2 piled urethane mats. Reaction time as an indication of attentional cost was measured by pressing a handheld button as quickly as possible in response to an auditory stimulus. A 2-way repeated-measures analysis of variance was performed to examine the differences between the 3 task conditions and the 2 age groups for each outcome. Results and Discussion:Trunk accelerations showed a statistically significant group-by-condition interaction in the anteroposterior (F = 9.1, P < .05), mediolateral (F = 9.9, P < .05), and vertical (F = 9.3, P < .05) directions. Muscle activity did not show a statistically significant group-by-condition interaction, but there was a significant main effect of condition in the tibialis anterior muscle (F = 33.1, P < .01) and medial gastrocnemius muscle (F = 14.7, P < .01) in young adults and the tibialis anterior muscle (F = 24.8, P < .01) and medial gastrocnemius muscle (F = 10.8, P < .01) in older adults. In addition, there was a statistically significant interaction in reaction time (F = 8.2, P < .05) for group-by-condition. Conclusions:The study results confirmed that reaction times in older adults are more prolonged than young adults in the same challenging postural control condition.

Associations between the settings of exercise habits and health-related outcomes in community-dwelling older adults.

[Purpose] The purpose of this study was to examine the associations between the settings of exercise habits and health-related outcomes in community-dwelling older adults. [Subjects] A total of 304 Japanese community-dwelling older adults (70.3 ± 4.1 years; 113 males and 191 females) participated in this study. [Methods] Demographic characteristics, medical conditions, exercise habits, and health-related outcomes were assessed by face-to-face interviews and self-reported questionnaires. Older adults who had exercise habits were classified into two groups: individual- and group-based exercise habits groups, and the health-related outcomes were compared between groups. [Results] The scores for the Geriatric Depression Scale, exercise self-efficacy, and dietary variety of older adults who had group-based exercise habits were better than those of older adults who had individual-based exercise habits. In addition, the exercise settings (individual- and group-based) were significantly associated with scores for the Geriatric Depression Scale (odds ratio = 0.76) and exercise self-efficacy (odds ratio = 1.26), even after adjusting for age and gender. [Conclusion] These results implied that habitual exercise in group settings may have an effective role in promoting exercise self-efficacy and mental health.

Investigation of the factor relevant to cognitive activity routinely in Japanese older adults

ity complications), and macrovascular complications (cardiovascular disease, stroke). Results: 17.29% (5,074) were diagnosed with dementia. Age-adjusted dementia incidence rates were highest amongNAs and blacks, lowest among Asians (Table). After adjustment for sex and education, dementia risk remained higher among NAs and blacks, lower among Asians, and similar among Latinos (relative to NHW) (Table). Further adjustment for T2DM severity and control as well as T2DM-related complications (microvascular or macrovascular) did not substantively alter hazard ratios for dementia (Table). Conclusions: Among older T2DM patients with uniform access to care, dementia risk was moderately higher among NAs and blacks, lower among Asians, and similar among Latinos, compared to NHW. These differences were robust to T2DM-related microvascular or macrovascular complications nor markers of T2DM severity and control. Among T2DM patients, blacks and NAs represent groupsmore susceptible to dementia. Racial/ethnic differences were not explained by a wide range of potential mediators.