Yosuke Osuka

Longitudinal association between habitual walking and fall occurrences among community-dwelling older adults: Analyzing the different risks of falling

The purpose of this longitudinal study was to examine the association between habitual walking and multiple or injurious falls (falls) among community-dwelling older adults, by considering the relative risk of falling. A cohort of Japanese community-dwelling older adults (n=535) aged 60-91 years (73.1±6.6 year, 157 men and 378 women) who underwent community-based health check-ups from 2008 to 2012 were followed until 2013. Incidence rate of falls between walkers and non-walkers was compared separately by the number of risk factors (Groups R0, R1, R2, R3 and R4+). The Cox proportional hazard model was used to assess the association between habitual walking and falls separately by lower- (R<2) and higher- (R≥2) risk groups. In Groups R0 and R1, the incidence of falls was lower in walkers than non-walkers; however, in Groups R2, R3, and R4+, the incidence of falls was higher in walkers. The Cox proportional hazard model showed that habitual walking was not significantly associated with falls (hazard ratio (HR): 0.88, 95% confidence interval (CI): 0.48-1.62) among the lower risk group but that it was significantly associated with increased falls (HR: 1.89, 95% CI: 1.04-3.43) among the higher risk group. The significant interaction between habitual walking and higher risk of falling was found (P<0.05). When individuals have two or more risk factors for falling, caution is needed when recommending walking because walking can actually increase their risk of experiencing multiple or injurious falls.

Walking can be more effective than balance training in fall prevention among community‐dwelling older adults

To examine the effects of walking on falls among community‐dwelling older adults while accounting for exposures.

Is a composite score of physical performance measures more useful than usual gait speed alone in assessing functional status

Overall physical performance can be represented by a composite score that is derived from upper and lower extremity performance measures. We aimed to identify whether composite scores of performance measures, particularly the lower extremity performance (LEP) score, upper extremity performance (UEP) score, and an overall score, are more accurate than usual gait speed (UGS) for assessing a wide range of functional status. We conducted a cross-sectional analysis on data from 701 community-dwelling older women (mean age 74.3 years). Trained testers measured UGS and the seven tests included in the composite scores. Using self-reported questionnaires, we assessed multiphasic functional status: physical function, higher-level functional capacity, mobility limitation, activities of daily living (ADLs), and falls. We compared the areas under the receiver operating characteristic curves (AUCs) of UGS with LEP, UEP, and overall scores for each status. We found no significant differences between the AUCs of UGS and LEP score for each status. The UEP score had significantly smaller AUCs for low physical function (0.73) and mobility limitation (0.78) than UGS alone (0.81 and 0.85, respectively), and the differences were substantial. Although the overall score had significantly greater AUCs for low higher-level functional capacity (0.83) and ADLs disability (0.83) than UGS alone (0.78 and 0.80, respectively), the differences were only 3-5%. The UGS should not be regarded solely as a measure of lower extremity function; this single test may represent overall physical performance. The UGS alone, which can be measured quickly and easily, suffice for assessing a wide range of functional status in older women.

Obesity and muscle weakness as risk factors for mobility limitation in community-dwelling older Japanese women: A two-year follow-up investigation

OBJECTIVES To examine the combined association of obesity and low muscle strength with mobility limitation in older adults. DESIGN, SETTING AND PARTICIPANTS This two-year follow-up longitudinal study included pooled data from 283 older community-dwelling Japanese women without mobility limitations who were 65 to 87 years of age (mean age 72.2 ± 5.0 years). MEASUREMENTS Muscle strength was measured by hand-grip strength (HGS). The participants were categorized by HGS (high muscle strength: HGS ≥19.6 kg, low muscle strength: HGS <19.6 kg) and body mass index (BMI) (obese: BMI ≥25 kg/m2, normal weight: BMI <25 kg/m2). The main outcome was mobility limitation, assessed by a self-reported questionnaire (difficulty walking one-half mile or climbing 10 steps without resting). Multivariate logistic regression analysis was performed to determine the combined effect of HGS and BMI on mobility limitation, adjusting for age, exercise habits, medications, and knee pain. RESULTS During the follow-up period, 82 of 283 participants (29.0%) developed mobility limitation. The adjusted odds ratios (95% confidence interval) for the incidence of mobility limitation were 1.53 (0.86-2.73) and 2.05 (1.08-3.91) in the obese and low muscle strength groups, respectively. Obesity combined with low muscle strength exhibited a significant and strong association with mobility limitation (odds ratio: 3.88, 1.08-13.91) compared with participants with normal weight and high muscle strength. CONCLUSION Among community-dwelling older Japanese women, obesity alone was not associated with the incidence of mobility limitation, but when combined with low muscle weakness, the risk of developing mobility limitation was 3.9-fold greater than for the reference group.

Comparison of a combination of upper extremity performance measures and usual gait speed alone for discriminating upper extremity functional limitation and disability in older women

Although usual gait speed (UGS) is considered an indicator of overall well-being, it is unclear whether upper extremity performance (UEP) measures provide a similar, additive contribution to functional status. We aimed to identify whether combining UEP measures can more accurately discriminate upper extremity functional limitation (UE limitation) and disability compared to UGS. We conducted a cross-sectional analysis on data from 322 community-dwelling older women, aged 65-96 years. Trained testers assessed UGS, and hand-grip strength (GRIP), functional reach (FR), back scratch, manipulating pegs (PEG), and moving beans with chopsticks as UEP measures. We assessed three functional statuses: UE limitation, activities of daily living (ADLs) and instrumental ADLs (IADLs) disabilities using self-reported questionnaires. Areas under the receiver operating characteristic curves (AUCs) were used to compare the discriminating power of UGS, with the individual and combined UEP measures for each status. Among UEP measures, only GRIP (AUC=0.68 for UE limitation, 0.81 for IADLs disability, and 0.84 for ADLs disability) could accurately discriminate each status as well as UGS (AUC=0.65, 0.83, and 0.91, respectively). Furthermore, UGS alone could discriminate UE limitation almost as well as the combination of GRIP, PEG, and FR (AUC=0.70). Combining other UEP measures did not help discriminate further. There were few advantages to combining UEP measures, and UGS or GRIP alone may suffice for assessing UE limitation and disability. However, the UGS should be the test of first choice, certainly more than GRIP, in routine assessment of functional limitation and disability, including UE limitation.

Physical performance measures as a useful indicator of multiple geriatric syndromes in women aged 75 years and older

To identify whether individual physical performance measures or a combination of measures is a better indicator of multiple geriatric syndromes (MGS) defined as the concomitant presence of more than one geriatric syndrome in an individual.

Association between habitual light‐intensity physical activity and lower‐extremity performance: A cross‐sectional study of community‐dwelling older Japanese adults

Habitual moderate vigorous‐intensity physical activity (MVPA) positively affects lower‐extremity performance. It is unclear whether habitual light‐intensity physical activity (LPA), such as leisurely walking, has similar effects on lower‐extremity performance. The aim of the present study was to identify the associations between habitual LPA and lower‐extremity performance in older adults.

Effects of aerobic and resistance training combined with fortified milk on muscle mass, muscle strength, and physical performance in older adults: A randomized controlled trial

ObjectivesFortified milk and resistance training (RT) increase muscle mass, muscle strength, and physical performance in older adults, but it remains unclear whether RT combined with aerobic training (AT) would have stronger effects on these outcomes. The purpose of this study was to examine the effects of aerobic and resistance training (ART) combined with fortified milk consumption on muscle mass, muscle strength, and physical performance in older adults.DesignOpen-labeled randomized controlled trial. Setting: University of Tsukuba.ParticipantsFifty-six older adults aged 65-79.InterventionParticipants were randomly allocated into resistance training (RT + fortified milk, n = 28) and aerobic and resistance training (ART + fortified milk, n = 28) groups. All participants attended supervised exercise programs twice a week at University of Tsukuba and ingested fortified milk every day for 12 weeks. Skeletal muscle index ([SMI]: appendicular lean mass/ height2) was assessed using dual-energy X-ray absorptiometry as a muscle mass measure. One-repetition maximum strength was measured using four kinds of resistance training machines (chest press, leg extension, leg curl, and leg press) as muscle strength measures. Sit-to-stand and arm curl tests were also assessed as physical performance measures.MeasurementsThe primary measurements were muscle mass and strength. The secondary outcomes were physical performance, blood samples, habitual diet, habitual physical activity, and medication use.ResultsAlthough the muscle strength and physical performance measures significantly improved in both groups, SMI significantly improved in only the RT group. There was no significant difference in the change in SMI and muscle strength measures between the two groups. However, the change in sit-to-stand and arm curl measures in the ART group were significantly higher than those in the RT group.ConclusionsThese results suggest that AT before RT combined with fortified milk consumption has similar effects on skeletal muscle mass and strength compared with RT alone, but it may be a more useful strategy to improve physical performance in older adults. Although the mechanism of our intervention is uncertain, our program would be an effective prevention for sarcopenia in older adults.

Association between muscular strength and intrarenal vascular resistance in middle-aged and older individuals

ABSTRACT A strategy for the preservation of intrarenal vasculature conditions remains obscure in middle‐aged and older individuals without the renal disease. In the present study, we sought to identify whether the maintenance of muscular strength is an effective method of preserving the intrarenal vasculature condition of middle‐aged and older individuals. Therefore, we applied a cross‐sectional approach for investigating the relationship between muscular strength and the condition of the intrarenal vasculature. In 169 middle‐aged and older individuals without renal disease, handgrip strength (HGS) and the renal resistive index (RRI) were measured as the parameters of muscular strength and intrarenal vascular resistance, respectively. The RRI was elevated with aging (rs = 0.499, P < 0.001) and was inversely correlated with HGS (rs = − 0.370, P < 0.001). The relationship between RRI and HGS remained significant after the consideration of confounders, including age and various central hemodynamic parameters. Furthermore, when the individuals were divided into four groups according to age (middle‐aged or older) and the median HGS values, the RRI exhibited the highest values in the older group with lower HGS values (P < 0.001). Our findings indicate that muscular strength as assessed by HGS is independently associated with the RRI (i.e. intrarenal vascular resistance) in middle‐aged and older individuals. This finding suggests that the muscular strength may be one of the key factors to preserve the intrarenal vasculature condition. HighlightsRenal resistive index increases with aging.Handgrip strength is independently associated with the renal resistive index.Muscular strength may be important to preserve intrarenal vasculature condition.

Age Scale for Assessing Activities of Daily Living

The purpose of this study was to develop an age scale for assessing activities of daily living (ADL) among community-dwelling adults aged 75 years or older. Participants were 1006 older Japanese: 312 men (79.6 ± 4.3 years) and 694 women, (79.9 ± 5.5 years). Participants completed a battery of 8 performance tests related to ADL and the Barthel index (BI) questionnaire. Spearman rank-order correlation analysis was applied to obtain the correlation of the 8 ADL performance tests with the total BI score. Three variables were high rank-order correlated with BI, secondly those items were subjected to the principal component analysis. The weighted combination of the principal component scores was summed. Resulting in an ADL score (ADLS), women = 0.075 X 1 – 0.082 X 2 – 0.063 X 3 + 0.124, men = 0.051 X 1 – 0.105 X 2 – 0.099 X 3 + 0.249, where X 1 = hand-grip strength, X 2 = timed up and go, X 3 = five-chair sit to stand. Individual ADLS was transformed to an ADL age scale (ADLA). The estimation was – 5.493 ADLS + 79.90 for women, and – 4.272 ADLS + 79.57 for men. Due to the distortion at the regression edges, the equation was corrected as suggested by Dubina et al . ADLA women after correction was = 0.447 (chronological age: CA) – 5.49ADLS + 44.17, men = 0.519CA – 4.27ADLS + 38.26. ADLA can be used to identify or monitor the characteristics of the ADL levels of physical abilities in older Japanese aged 75 years or older.