Published papers

Aim: To assess the burdens of polypharmacy and the drug burden index in community-dwelling elder people.Methods: The survey was conducted on 396 participants who participated in The Kawasaki Wellbeing Project from March to December 2017. We investigated the associations between the drug burden and the physical/cognitive/mental outcomes. The drug burden was determined by calculating the number of medications and the drug burden index (DBI) based on the use of anticholinergic and sedative drugs. A multivariate regression analysis was conducted for the outcome measures ADL, IADL, MMSE, J-CHS, and EQ5D5L after adjusting for the sex, age, number of diseases, education level, smoking history, and alcohol history.Results: A total of 389 subjects were analyzed, the mean age of the population was 86 years old, and 187 people (48%) were male. Polypharmacy was reported in 243 people (62%), and DBI exposure was reported for 142 people (36.5%). We found that this population was physically healthy, with a median ADL of 100, and had high quality of life, with a median EQ5D5L of 0.895. Polypharmacy was found to be related to the J-CHS (β: 0.04) and EQ5D5L (−0.01). The DBI was also related to the EQ5D5L (−0.04).Conclusion: These results showed that even though this population was healthier than the general Japanese elderly population, the drug burden of polypharmacy and high dosages of anticholinergic/sedative drugs exerted significant negative effects on frailty and the quality of life. Additional research should be conducted to investigate the long-term effects of polypharmacy and anticholinergic/sedative drugs on elderly people.

Background: The use of mobile apps has promoted physical activity levels. Recently, with an increasing number of older adults accessing the internet, app-based interventions may be feasible in older populations. Peer support-based interventions have become a common method for promoting health-related behavior change. To our knowledge, the feasibility of using digital peer support apps (DPSAs) to increase physical activity among older adults and its impact on physical activity and physical function have not been investigated. Objective: This study aims to assess the feasibility of using DPSAs in older adults and to assess changes in physical activity and physical function in DPSA users. Methods: We conducted a nonrandomized controlled trial of older adults aged ≥65 years. We recruited participants for 2 distinct 12-week programs designed to increase physical activity. Participants could choose between an intervention group (app program and exercise instruction) or a control group (exercise instruction only). DPSA creates a group chat for up to 5 people with a common goal, and participants anonymously post to each other in the group. Once a day, participants posted a set of their step counts, photos, and comments on a group chat box. The intervention group used the DPSA after receiving 2 face-to-face lectures on its use. The participants were characterized using questionnaires, accelerometers, and physical function assessments. The feasibility of the DPSA was assessed using retention and adherence rates. Physical activity was assessed using accelerometers to measure the daily step count, light intensity physical activity, moderate to vigorous intensity physical activity (MVPA), and sedentary behavior. Physical function was assessed using grip strength and the 30-second chair-stand test. Results: The participants in the intervention group were more frequent users of apps, were more familiar with information and communication technology, and had a higher baseline physical activity level. The retention and adherence rates for the DPSA intervention were 88% (36/41) and 87.7%, respectively, indicating good feasibility. Participants in the intervention group increased their step count by at least 1000 steps and their MVPA by at least 10 minutes using the DPSA. There was a significant difference in the interaction between groups and intervention time points in the daily step count and MVPA (step count, P=.04; duration of MVPA, P=.02). The DPSA increased physical activity, especially in older adults with low baseline physical activity levels. Conclusions: The feasibility of DPSA was found to be good, with the intervention group showing increases in daily steps and MVPA. The effects of DPSA on step count, physical activity, and physical function in older adults with low baseline physical activity should be investigated using randomized controlled trials.

Background: As the Japanese population continues to age, functional decline with aging will inevitably become more pronounced. Vision loss and decline in lifestyle and motor functions are the main causes of functional decline. To date, a few studies have examined the relationship between visual and overall physical function. Therefore, this study aimed to quantitatively investigate the relationship between loss of visual acuity and the decline of physical functionality. Methods: This cross-sectional study was based on the data of 86 community-dwelling older adults (average age ± standard deviation, 75.7 ± 5.5 years; 34 men) who participated in the October 2020–May 2022 baseline survey. Visual function was assessed based on the measurement of binocular near functional visual acuity (NFVA) using the Smart Vision Check application. Physical function tests were performed by measuring grip strength, 30-second chair stand (CS-30), Timed Up and Go (TUG), with eyes open, one-leg standing balance (OLSB), and two-step test. Multivariate regression analysis was performed to examine the association between NFVA and physical function, and partial regression coefficient (β) and 95% confidence interval (95%CI) were calculated. Results: After adjusting for all covariates, NFVA was significantly associated with grip strength (β: 3.54, 95%CI: 0.39, 6.70). Meanwhile, no association was noted between NFVA and CS-30 (β: -0.35, 95%CI: -2.68, 1.97), TUG (β: -0.23, 95%CI: -0.65, 0.19), OLSB (β: 6.13, 95%CI: -5.09, 17.35), and two-step test (β: 0.01, 95%CI: -0.05, 0.08). Conclusions: The study showed an association between quantitatively assessed visual and physical functions in community-dwelling older adults living in Japan. Thus, the findings indicate that maintaining and enhancing grip strength and visual function in older adults may be an important factor in leading a healthy and fulfilling life. Trial registration: Registration number, UMIN000041970.

Objective. The aim of this study was to evaluate the relationships between the composition of free fatty acids (FFAs) and metabolic parameters, including body fat distribution, in Japanese. Methods. The study subjects were 111 Japanese patients (54 males, 57 females). Metabolic parameters and visceral and subcutaneous fat areas as determined by CT scanning at the umbilical level were measured. Glucose tolerance test (GTT) was performed by administering 75 g glucose orally. Results. The percentage of linoleic acid (C18:2), the greatest constituent among FFAs, was negatively correlated with visceral fat area (r = -0.411, p < 0.0001), fasting glucose (r = -0.330, p < 0.0001), HbA1c (r = -0.231, p = 0.0146), and systolic blood pressure (r = -0.224, p = 0.0184). Linoleic acid percentage was also significantly negatively correlated with HOMA-IR (r = -0.416, p < 0.0001) by simple correlation. Based on the findings of OGTT, the 111 subjects were classified into three groups: 33 with normal glucose tolerance, 71 with impaired glucose tolerance (IGT), and 7 diabetic subjects. The percentage of serum linoleic acid in diabetic subjects was significantly lower than that in normal subjects. Conclusion. We conclude that serum linoleic acid level is negatively correlated with the accumulation of visceral fat in relation to a reduction of insulin resistance in Japanese subjects.

This study investigated the relationships between muscle echo intensity (EI), physical activity (PA), and functional mobility in 108 Japanese (88-92 years). We measured EI and muscle thickness (MT) at the midpoint of the anterior superior iliac spine and patella using B-mode ultrasound. Light and moderate-to-vigorous PA (LPA and MVPA) were assessed with a triaxial accelerometer. The timed up and go (TUG) test was used to measure for functional mobility. EI, but not MT, was significantly associated with both TUG scores (beta = 0.17, p =.047) and MVPA (beta = -0.31, p =.01) when adjusted by potential confounders. However, association between EI and TUG disappeared after adjusted for MVPA. Meanwhile, MVPA was significantly associated with TUG scores independent of EI (beta = -0.35, p <.001). Although EI of anterior thigh muscles might be a weaker predictor of functional morbidity than MVPA, it is a noninvasive and practical approach for assessing muscle quality in the very old.

BACKGROUND: To date, there is no physical activity (PA) questionnaire with convergent and construct validity for the oldest-old. The aim of the current study was to investigate the validity of questionnaire-assessed PA in comparison with objective measures determined by uniaxial and triaxial accelerometers and physical performance measures in the oldest-old. METHODS: Participants were 155 elderly (mean age 90 years) who were examined at the university and agreed to wear an accelerometer for 7 days in the 3-year-follow-up survey of the Tokyo Oldest-Old Survey of Total Health. Fifty-nine participants wore a uniaxial and triaxial accelerometer simultaneously. Self-rated walking, exercise, and household PA were measured using a modified Zutphen PA Questionnaire (PAQ). Several physical performance tests were done, and the associations among PAQ, accelerometer-assessed PA, and physical performances were compared by Spearman's correlation coefficients. RESULTS: Significant, low to moderate correlations between PA measures were seen on questionnaire and accelerometer assessments (rho = 0.19 to 0.34). Questionnaireassessed PA measure were correlated with a range of lower extremity performance (rho = 0.21 to 0.29). CONCLUSIONS: This PAQ demonstrated convergent and construct validity. Our findings suggest that the PAQ can reasonably be used in this oldest-old population to rank their PA level.