Relationship between quadriceps muscle computed tomography measurement and motor function, muscle mass, and sarcopenia diagnosis.

Background: The quadriceps muscle is one of the human body's largest and most clinically important muscles and is evaluated using mid-thigh computed tomography (CT); however, its relationship with motor function and sarcopenia remains unclear. Herein, we investigated the relationship between the cross-sectional area (CSA) of the quadriceps muscle, CT attenuation value (CTV), dual-energy X-ray absorptiometry muscle mass measurements, and muscle strength and motor function to evaluate the relationship between muscle mass loss and motor function decline, determine the diagnostic ability for sarcopenia, and confirm the usefulness of quadriceps muscle CT evaluation. Methods: A total of 472 middle-aged and older community dwellers (254 men and 218 women) aged ≥40 years (mean age: 62.3 years) were included in this study. The quantity and quality of the quadriceps muscle were assessed using CSA and CTV (CSA×CTV) as a composite index multiplied by quality and quantity. Age-adjusted partial correlations by sex with eight motor functions (knee extension muscle strength, power, normal walking speed, fast walking speed, grip strength, sit-up ability, balance ability, and reaction time) were evaluated, including correction methods for height, weight, and body mass index (BMI). Further, the accuracy of sarcopenia diagnosis was evaluated using appendicular muscle mass with dual-energy X-ray absorptiometry measurements, grip strength, and walking speed as the gold standard, and receiver operating characteristic curves were plotted to evaluate diagnostic performance. Results: In men, CSA and CSA×CTV were significantly associated with seven of the eight motor functions (p<0.05), excluding only balance ability. BMI-corrected CSA was significantly correlated with all eight motor functions in men and women (p<0.05). In the diagnosis of sarcopenia based on skeletal muscle index, CSA (area under the curve (AUC) 0.935) and CSA×CTV (AUC 0.936) and their correction by height (CSA/height (AUC 0.917) and CSA×CTV/height (AUC 0.920)) were highly accurate and useful for diagnosis in men but moderately accurate in women (CSA (AUC 0.809), CSA×CTV (AUC 0.824), CSA/height (AUC 0.799), CSA×CTV/height (AUC 0.814)). Conclusion: The present results showed that a single CT image of the quadriceps muscle at the mid-thigh is useful for diagnosing sarcopenic changes, such as loss of muscle mass, muscle weakness, and muscle function.

Effects of work-family life support program on the work-family interface and mental health among Japanese dual-earner couples with a preschool child: A randomized controlled trial.

OBJECTIVES: This study examined the effectiveness of a newly developed work-family life support program on the work-family interface and mental health indicators among Japanese dual-earner couples with a preschool child(/ren) using a randomized controlled trial with a waitlist. METHODS: Participants who met the inclusion criteria were randomly allocated to the intervention or the control groups (n = 79 and n = 85, respectively). The program comprised two 3-h sessions with a 1-month interval between them and provided comprehensive skills by including self-management, couple management, and parenting management components. The program sessions were conducted on weekends in a community center room with 3-10 participants. Outcomes were assessed at baseline, 1-month, and 3-month follow-ups. Primary outcomes were work-family balance self-efficacy (WFBSE), four types of work-family spillovers (i.e., work-to-family conflict, family-to-work conflict, work-to-family facilitation, and family-to-work facilitation), psychological distress, and work engagement reported by the participants. RESULTS: The program had significantly pooled intervention effects on WFBSE (P = .031) and psychological distress (P = .014). The effect sizes (Cohen's d) were small, with values of 0.22 at the 1-month follow-up and 0.24 at the 3-month follow-up for WFBSE, and -0.36 at the 3-month follow-up for psychological distress. However, the program had nonsignificant pooled effects on four types of work-family spillovers and work engagement. CONCLUSIONS: The program effectively increased WFBSE and decreased psychological distress among Japanese dual-earner couples with a preschool child(/ren).

No Appreciable Effect of Education on Aging-Associated Declines in Cognition: A 20-Year Follow-Up Study.

Education has been claimed to reduce aging-associated declines in cognitive function. Given its societal relevance, considerable resources have been devoted to this research. However, because of the difficulty of detecting modest rates of change, findings have been mixed. These discrepancies may stem from methodological shortcomings such as short time spans, few waves, and small samples. The present study overcame these limitations (N = 1,892, nine waves over a period of 20 years). We tested the effect of education level on baseline performance (intercept) and the rate of change (slope) in crystallized and fluid cognitive abilities (gc and gf, respectively) in a sample of Japanese adults. Albeit positively related to both intercepts, education had no impact on either the gc or the gf slope. Furthermore, neither intercept exhibited any appreciable correlation with either slope. These results thus suggest that education has no substantial role (direct or mediated) in aging-related changes in cognition.

Longitudinal Changes in Physical and Cognitive Functions among Participants with and without Rheumatoid Arthritis in Community-Dwelling Middle-Aged and Older Adults.

BACKGROUND: This study evaluated the chronological changes in physical and cognitive functions in middle-aged and older adults with and without rheumatoid arthritis (RA). METHODS: This population-based case-control longitudinal study included individuals aged 40-79 years at baseline who agreed to participate. We identified 42 participants with RA and randomly selected 84 age- and sex-matched controls. Physical function was assessed according to gait speed, grip strength, and skeletal muscle mass. Cognitive function was assessed based on the information, similarities, picture completion, and digit symbol substitution test scores of the Wechsler Adult Intelligence Scale-Revised Short Form. The general linear mixed models comprised the fixed effects of the intercept, case, age, time in years since baseline, and case×time interaction, which were used to examine longitudinal changes in physical and cognitive functions. RESULTS: Regardless of RA status, grip strength decreased and the picture completion score increased in the group aged <65 years, while skeletal muscle mass index and gait speed decreased in the group aged ≥65 years. The interaction of case×follow-up years for grip strength in the group aged ≥65 years was significant (p=0.03). The decline in grip strength in the control group (slope=-0.45) was greater than that in the RA group (slope=-0.19). CONCLUSION: Chronological changes in physical and cognitive functions were comparable between participants with and without RA; however, the decline in grip strength in the control group was greater among older adults with RA.

Twenty-year prospective cohort study of the association between a Japanese dietary pattern and incident dementia: the NILS-LSA project.

PURPOSE: Evidence has suggested that adherence to a Japanese diet may be beneficial for health. However, its association with incident dementia remains unclear. The aim was to explore this association in older Japanese community-dwellers, taking apoprotein E genotype into consideration. METHODS: A 20-year follow-up cohort study involving 1504 dementia-free older Japanese community-dwellers (aged 65-82 years) living in Aichi Prefecture, Japan, was conducted. Based on a previous study, a 9-component-weighted Japanese Diet Index (wJDI9) score (range - 1 to 12) was calculated using 3-day dietary record data and used as an indicator of adherence to a Japanese diet. Incident dementia was confirmed by the Long-term Care Insurance System certificate, and dementia events occurring within the first 5 years of follow-up were excluded. A multivariate-adjusted Cox proportional hazards model was used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for incident dementia, and Laplace regression was used to estimate percentile differences (PDs) and 95% CIs (expressed in months) in age at incident dementia (i.e., dementia-free duration differences), according to tertiles (T1-T3) of wJDI9 scores. RESULTS: The median (IQR) follow-up duration was 11.4 (7.8-15.1) years. During the follow-up period, 225 (15.0%) cases of incident dementia were identified. Because the smallest prevalence of incident dementia was 10.7% for the T3 group of wJDI9 scores, to avoid inaccurately estimating the dementia-free duration of participants in the T3 group, the 11th PDs in age at incident dementia between the T1 and T3 groups of wJDI9 scores were estimated. A higher wJDI9 score was associated with a lower risk of incident dementia and a longer dementia-free duration difference. The multivariate-adjusted HR (95% CI) and 11th PDs (95% CI) in age at incident dementia for participants in the T1 vs. T3 group were 1.00 (reference) vs. 0.58 (0.40, 0.86), and 0 (reference) vs. 36.7 (9.9, 63.4) months, respectively. Each 1-point increase of the wJDI9 score was associated with a 5% lower risk of incident dementia (P value = 0.033) and 3.9 (0.3, 7.6) additional months of dementia-free duration (P value = 0.035). No differences were seen in sex or smoking status (current smoker vs. non-current smoker) at baseline. CONCLUSION: These findings suggest that adherence to a Japanese diet defined by wJDI9 is associated with a lower risk of incident dementia in older Japanese community-dwellers, suggesting the benefit of the Japanese diet for dementia prevention.

Effect of different types of social support on physical frailty development among community-dwelling older adults in Japan: Evidence from a 10-year population-based cohort study.

PURPOSE: Social support is associated with multiple positive health outcomes and is negatively associated with frailty in older adults. However, most evidence came from cross-sectional research. This study aimed to longitudinally explore the relationship between different types of social support and incident physical frailty. MATERIALS AND METHODS: A 10-year prospective cohort study data from the National Institute for Longevity Sciences - Longitudinal Study of Aging (NILS-LSA) database, from 2000 to 2012 on older adults aged ≥65 years were analyzed excluding those with physical frailty at baseline, missing data, or not attending follow-up. We measured three kinds of social support, whether from within or outside family members, including emotional, instrumental, and negative support. The generalized estimating equation (GEE) model was used to examine the longitudinal relationships between social support and subsequent frailty. RESULTS: The final analysis included 466 participants, with an average age of 71.3 (standard deviation [SD], 4.3) years and 7.33 years of follow-up (SD, 3.11). GEE analysis showed that emotional and instrumental supports from within and outside family members were associated with a significantly lower risk of physical frailty (odd ratio (OR) and 95% confidence interval (CI): 0.80 [0.64-1.00] and 0.74 [0.58-0.95]; 0.77 [0.60-0.99] and 0.79 [0.63-0.99], respectively). Both negative support from within or outside family members had no significant relationship with the risk of physical frailty. CONCLUSIONS: This longitudinal study suggested that emotional, and instrumental support both from within or outside family members can reduce future physical frailty among older adults.

Influence of vitamin D on sarcopenia pathophysiology: A longitudinal study in humans and basic research in knockout mice.

BACKGROUND: Vitamin D is an essential nutrient in musculoskeletal function; however, its relationship to sarcopenia remains ambiguous, and the mechanisms and targets of vitamin D activity have not been elucidated. This study aimed to clarify the role of vitamin D in mature skeletal muscle and its relationship with sarcopenia. METHODS: This epidemiological study included 1653 community residents who participated in both the fifth and seventh waves of the National Institute for Longevity Sciences, Longitudinal Study of Aging and had complete background data. Participants were classified into two groups: vitamin D-deficient (serum 25-hydroxyvitamin D < 20 ng/mL) and non-deficient (serum 25-hydroxyvitamin D ≥ 20 ng/mL); they underwent propensity-score matching for background factors (age, sex, height, weight, comorbidities, smoker, alcohol intake, energy intake, vitamin D intake, steps, activity, season and sarcopenia). Changes in muscle strength and mass over the 4-year period were compared. For basic analysis, we generated Myf6CreERT2 Vitamin D Receptor (VDR)-floxed (VdrmcKO ) mice with mature muscle fibre-specific vitamin D receptor knockout, injected tamoxifen into 8-week-old mice and analysed various phenotypes at 16 weeks of age. RESULTS: Grip strength reduction was significantly greater in the deficient group (-1.55 ± 2.47 kg) than in the non-deficient group (-1.13 ± 2.47 kg; P = 0.019). Appendicular skeletal muscle mass reduction did not differ significantly between deficient (-0.05 ± 0.79 kg) and non-deficient (-0.01 ± 0.74 kg) groups (P = 0.423). The incidence of new cases of sarcopenia was significantly higher in the deficient group (15 vs. 5 cases; P = 0.039). Skeletal muscle phenotyping of VdrmcKO mice showed no significant differences in muscle weight, myofibre percentage or myofibre cross-sectional area; however, both forelimb and four-limb muscle strength were significantly lower in VdrmcKO mice (males: forelimb, P = 0.048; four-limb, P = 0.029; females: forelimb, P < 0.001; four-limb, P < 0.001). Expression profiling revealed a significant decrease in expression of sarcoendoplasmic reticulum Ca2+ -ATPase (SERCA) 1 (P = 0.019) and SERCA2a (P = 0.049) genes in the VdrmcKO mice. In contrast, expression of non-muscle SERCA2b and myoregulin genes showed no changes. CONCLUSIONS: Vitamin D deficiency affects muscle strength and may contribute to the onset of sarcopenia. Vitamin D-VDR signalling has minimal influence on the regulation of muscle mass in mature myofibres but has a significant influence on muscle strength.

Natural History Trajectories of Frailty in Community-Dwelling Older Japanese Adults.

BACKGROUND: The gap between the average life expectancy and healthy life expectancy remains wide. Understanding the natural history of frailty development is necessary to prevent and treat frailty to overcome this gap. This study elucidated the trajectories of 5 frailty assessment components using group-based multitrajectory modeling. METHODS: Overall, 845 community-dwelling older adults (aged 65-91 years; 433 males and 412 females) who underwent longitudinal frailty assessments at least 3 times were included in the analysis. The mean follow-up period (±SD, range) was 7.1 (±2.3, 3.8-11.3) years. In each wave, the physical frailty was assessed for the following 5 partially modified components of the Cardiovascular Health Study criteria: shrinking, weakness, exhaustion, slowness, and low activity. Using group-based multitrajectory modeling, we identified subgroups that followed distinctive trajectories regarding the 5 frailty components. RESULTS: Five frailty trajectory groups were identified: weakness-focused frail progression group (Group 1 [G1]; 10.9%), robust maintenance group (Group 2 [G2]; 43.7%), exhaustion-focused prefrail group (Group 3 [G3]; 24.3%), frail progression group (Group 4 [G4]; 6.7%), and low activity-focused prefrail group (Group 5 [G5]; 14.4%). The Cox proportional hazards model analysis showed that G1, G4, and G5 had significantly higher mortality risks after adjusting for sex and age (G2 was the reference group). CONCLUSION: Based on the natural history of frailty, the 5 distinctive trajectory groups showed that some individuals remained robust, while others remained predominantly prefrail or progressed primarily owing to physical mobility decline. Therefore, identifying individuals belonging to these progressive frailty groups and providing interventions according to the characteristics of each group may be beneficial.

Typology of Work-Family Balance Among Middle-Aged and Older Japanese Adults.

This study explores the clusters of work-family balance (WFB) among Japanese middle-aged and older adults and clarifies the characteristics of the derived clusters. Data on working adults (N = 1,351; age range = 40-85 years) were drawn from a pool of participants in the National Institute for Longevity Sciences-Longitudinal Study of Aging. The WFB scale consists of subscales assessing work-family conflict (WFC) and work-family facilitation (WFF). First, a cluster analysis was performed using the WFB scale, and four clusters were extracted. Second, we examined associations between the four clusters and related variables such as demographic characteristics, work, family, and lifestyle factors, social support, and mental health. Our findings showed that the clusters included high-WFC/high-WFF, high-WFC/low-WFF, low-WFC/high-WFF, and low-WFC/low-WFF. Differences were found in related variables among the clusters. Specifically, those in the Low-WFC/High-WFF cluster had a good lifestyle, received the highest levels of social support, and had the fewest mental health issues. Our findings have implications for maintaining sufficient WFB and promoting positive mental health among workers.

Breakfast Protein Quality and Muscle Strength in Japanese Older Adults: A Community-Based Longitudinal Study.

OBJECTIVES: The amount of breakfast protein intake is important for maintaining muscle strength. However, the effect of breakfast protein quality (ie, bioavailability) remains unclear. We investigated the association between breakfast protein quality and the incidence of muscle weakness. DESIGN: Longitudinal study. SETTING AND PARTICIPANTS: Healthy older adults age 60-83 years without stroke, arthritis, Parkinson disease, or muscle weakness at baseline (maximum follow-up period and participations were 9.2 years and 5 times, respectively). METHODS: Weakness was defined by the Asian Working Group for Sarcopenia 2019 criteria, using grip strength. Breakfast protein quality was evaluated using the protein digestibility-corrected amino acid score (PDCAAS), where higher scores represent higher quality, calculated from 3-day dietary records. Participants were classified according to sex-stratified tertiles of breakfast PDCAAS (ie, low to high groups). The association between PDCAAS and incident weakness was analyzed using the generalized estimating equation, after adjusting for sex, age, follow-up time, grip strength, body mass index, physical activity, cognition, education, smoking, economics, medical history, lunch and dinner PDCAASs, and energy and protein intake during 3 regular meals at baseline. RESULTS: Overall, 14.4% of the initial sample was excluded owing to a diagnosis of weakness-related diseases, and 58.3% (n = 701) had at least 1 follow-up measurement for inclusion in the analysis. The mean ± SD follow-up period was 6.9 ± 2.1 years; the cumulative number of participants was 3019, and 282 developed weakness. Using the low PDCAAS group as the reference, the adjusted odds ratios (95% CIs) for incident weakness in the middle and high PDCAAS groups were 0.71 (0.43-1.18) and 0.50 (0.29-0.86), respectively. CONCLUSIONS AND IMPLICATIONS: Higher breakfast protein quality was associated with a reduction in incident weakness in older adults, independent of protein intake. These findings may highlight the role of protein quality for muscle health in older adults.

[Cross-sectional association between the amino acid intake and episodic memory in middle- and old-aged community dwellers].

AIM: The specific amino acid intake has been suggested to be positively associated with the cognitive function. However, few reports have investigated the association between the amino acid intake and episodic memory (EM). Therefore, we investigated this association. METHODS: Data were obtained from the fourth survey (2004-2006) of the National Institute for Longevity Sciences - Longitudinal Study of Aging. We analyzed 2,082 participants 40-85 years old (50.1% male). The dietary intake was assessed by the three-day dietary records, and participants were classified into sex- and age-specific tertiles of protein and amino acid intakes. EM was assessed using the Logical Memory II of the Wechsler Memory Scale. The association of protein and amino acid intakes with EM was analyzed using the general linear model. Covariates were sex, age, body mass index, education, depressive symptoms, smoking status, employment status, living alone, and medical history in model 1. The energy intake was added to model 1 in model 2. The protein intake was added to model 2 in model 3. RESULTS: The mean (standard deviation) age was 59.4 (12.3) years old. After adjusting for the energy intake, the EM tended to be higher with a higher protein intake (p=0.053 for group differences and p=0.015 for trends). Furthermore, after adjusting for energy and protein intake, EM was significantly higher with higher intakes of isoleucine, leucine, lysine, methionine, phenylalanine, tyrosine, tryptophan, valine, and histidine (p< 0.05, both for group differences and trends). CONCLUSION: Our findings suggest a positive association between EM and the intake of essential and semi-essential amino acids, independent of the protein and energy intake.

Association between intra-individual changes in social network diversity and global cognition in older adults: Does closeness to network members make a difference?

OBJECTIVE: Although qualitative aspects of interpersonal networks, such as diversity or closeness, can protect the health of older adults, their association with cognitive health remains unclear. This study examined the concurrent and time-lagged association between intra-individual changes in global cognition and social network diversity, while considering emotional closeness. METHODS: In this 10-year study, we obtained six-wave, biennial data from the National Institute for Longevity Sciences, Longitudinal Study of Aging. Data from 808 community-dwelling, cognitively intact adults aged 65 or older at baseline were analyzed. Global cognition was assessed using the Mini-Mental State Examination (MMSE). Social network diversity scores were assessed using a social convoy model, comprising three closeness levels: inner (closest), middle (second closest), and outer (least close). RESULTS: The mean age of the respondents was 72.0 ± 4.4 years at baseline, and 50.1% were male. A fixed-effects model showed that intra-individual change in total (coefficients, B: 0.10; standard error [SE]: 0.05; p = .042) and inner (B: 0.25; SE: 0.07; p < .001) social network diversity was significantly associated with MMSE score decline, even after adjusting for covariates. Yet, in time-lagged models, diversity and MMSE score changes were not significantly associated during the subsequent two years. CONCLUSION: Older adults' global cognition declined when the diversity of their closest social network decreased. This may be a promising marker for early cognitive decline in older adults. Indeed, their closest networks are relatively unlikely to decline as part of normal aging or diseases except dementia.

Vasomotor symptoms, sleep problems, and depressive symptoms in community-dwelling Japanese women.

AIM: To assess prevalence and characteristics of vasomotor symptoms in community-dwelling Japanese women. METHODS: These were cross-sectional analyses using data from the National Institute for Longevity Sciences-Longitudinal Study of Aging. The main outcome measures were prevalence and severity of hot flashes and sweating. Associations between hot flashes/sweating (slight, moderate, or severe vs none) and sleep problems were explored using logistic regression, with and without adjustment for age, daily physical activity, and number of urinations/night. Associations between hot flashes/sweating and sleep problems, depressive symptoms, and dietary variables were explored in logistic regression models or general linear models. RESULTS: A total of 1152 women between 40 and 91 years of age were enrolled. Hot flashes were reported by 24.5% of participants; with prevalence and severity highest in those 50-54 years or 2-5 years postmenopause. Sleep problems were reported 15 percentage points more frequently by women who reported hot flashes than by those without hot flashes. Adjusted odds ratios [95% CI] for difficulty in falling asleep and difficulty in sleeping through were 2.09 [1.565-2.796] and 2.07 [1.549-2.763]), respectively. Also, hot flashes were associated with higher risk of depressive symptoms (adjusted odds ratio [95% CI]: 2.99 [2.07-4.32]) and lower life satisfaction, self-esteem, and self-rated health status. A similar pattern was observed in women with and without sweating. No associations were found between hot flashes and dietary factors. CONCLUSIONS: Clear associations were found between hot flashes and sleeping problems, even after adjusting for potential confounding factors. Women who reported hot flashes also reported worse mental and physical health than those who did not report hot flashes.

Green tea consumption is associated with annual changes in hippocampal volumes: A longitudinal study in community-dwelling middle-aged and older Japanese individuals.

BACKGROUND: To investigate the association between green tea consumption and the annual rate of change of gray matter (GM), white matter (WM), and hippocampal volumes in community-dwelling middle-aged and older Japanese individuals. METHODS: A prospective cohort study with two years of follow-up was conducted as part of the National Institute for Longevity Sciences-Longitudinal Study of Aging (NILS-LSA) project. A total of 1693 participants (862 men and 831 women, aged 40-89 years) were included. Green tea consumption (mL/day) data were collected with a 3-day dietary record. Volumes of GM, WM, and the hippocampus were estimated by T1-weighted brain magnetic resonance imaging and FreeSurfer software. The GM ratio, WM ratio, and hippocampal ratio (HR) were calculated as the percentages of total intracranial volume, respectively. RESULTS: The mean (SD) annual rate of change of hippocampal volume [(HR at baseline - HR at follow-up)/HR at baseline/follow-up years×100%] was 0.499 (1.128) (%). In the multivariable-adjusted general linear model, green tea consumption was negatively associated only with the annual rate of change of hippocampal volume (%) [ß (95% CI) for each 1 mL/day increase in green tea consumption = -20.2E-5 (-35.0E-5 to -5.3E-5); P-value = 0.008]. No associations were observed for the annual rate of change of GM or WM volumes. The results remained significant when the analysis was limited to those with stable green tea consumption and were especially evident among individuals aged 65 years and older and among women. CONCLUSIONS: In this study, higher green tea consumption was associated with less annual hippocampal atrophy, and each additional 100 mL/day of green tea intake was related to a reduction of approximately 5% in annual hippocampal atrophy. This association was especially evident among older individuals and among women. Further study in different settings is needed to confirm this association.

Differences in the mass and quality of the quadriceps with age and sex and their relationships with knee extension strength.

BACKGROUND: Although muscle quality evaluations are currently considered important for diagnosing sarcopenia, data from the general population are lacking. This study used mid-thigh computed tomography measurements to evaluate age-related and sex-related differences in quadriceps femoris muscle quality and mass and their relationships with knee extension strength (KES). METHODS: Cross-sectional data from 520 Japanese individuals (273 men and 247 women, mean age: 63.1 ± 10.6 years) were analysed. Mass and quality were assessed using quadriceps cross-sectional areas (CSAs) and computed tomography values (CTVs), respectively. The four constituent muscles, intermuscular adipose tissue, and entire quadriceps area (total quadriceps muscles + intermuscular adipose tissue) were assessed, and the data were stratified by five age groups and sex. To evaluate age-related decline, linear and quadratic equations were tested for fit according to the constituent muscles and sex. KES could be measured in 472 of the 520 participants (254 men and 218 women, mean age: 62.3 ± 10.3). Multiple linear regression analyses with age-adjusted models were then used for evaluating the relationships between KES and quadriceps measurements. RESULTS: All muscle CSAs and CTVs showed downward trends with age (men: P < 0.001 for all; women: vastus medialis CTV, P = 0.004; others, P < 0.001); the intermuscular adipose tissue CSA did not show any trend (men: P = 0.938; women: P = 0.139), although its percentage of the entire quadriceps area showed an upward trend in both sexes (P < 0.001). Men exhibited a quadratic decline in the CSAs for the entire quadriceps area (P = 0.016), total quadriceps muscles (P = 0.021), the vastus medialis (P = 0.010) and vastus lateralis (P = 0.038), and all CTVs (rectus femoris, P = 0.044; others, P < 0.001). Women exhibited a quadratic equation in the CTV for rectus femoris (P = 0.031), but a linear decline in the other variables (P < 0.001 for all). Both the total quadriceps muscles CSA and CTV were significantly associated with KES in both sexes (P < 0.001). For each muscle, the CSAs of the vastus medialis (P < 0.001) and vastus intermedius (P = 0.001) were significantly associated with KES in men, whereas the vastus medialis CSA (P < 0.001), vastus lateralis CSA (P = 0.006), rectus femoris CSA (P = 0.020), and vastus intermedius CTV (P = 0.025) were significantly associated with KES in women CONCLUSIONS: Age-related quadriceps femoris changes in mass and quality differed by sex and the constituent muscles. The constituent muscles contributing to KES differed between men and women. Quadriceps CSA and CTV measurements are useful for objectively assessing age-related and sex-related muscle deterioration and KES.

Intake of isoflavones reduces the risk of all-cause mortality in middle-aged Japanese.

BACKGROUND/OBJECTIVES: To clarify the effects of intake of legumes and isoflavones on all-cause mortality in middle-aged and older Japanese. SUBJECT/METHODS: The subjects were 2136 randomly chosen community-dwelling Japanese men and women aged 40-79 years who participated in a first-wave survey (1997-2000; baseline). The subjects were followed from baseline to December 31, 2017 (mean period of 16.6 ± 4.2 years). Intake of legumes, soybeans, and isoflavones at baseline was assessed using a 3-day dietary record with photographs. The relationships of intake amounts of legumes and isoflavones to mortality were assessed using Cox proportional hazards regression controlling for age, sex, education, employment, body mass index, smoking habits, medical histories, drinking, and energy intake. RESULTS: There were 491 deaths during the follow-up period. We found inverse associations of the intake of total soy products and intake of each of the isoflavones with all-cause mortality (p for trend < 0.05) in subjects aged < 60 years: the multivariate-adjusted hazard ratios (95% confidence intervals) for all-cause mortality in the highest intake group (third tertile) of total soy products and total isoflavones were 0.32 (0.13-0.78) and 0.35 (0.17-0.73), respectively, compared with the reference group (first tertile). In contrast, there were no significant associations of intake amounts of legumes, soybeans, and isoflavones with all-cause mortality in subjects aged 60 years or older. CONCLUSIONS: The findings suggest that a higher intake of isoflavones might decrease the risk of all-cause mortality, especially in middle-aged Japanese.

Dietary diversity is associated with longitudinal changes in hippocampal volume among Japanese community dwellers.

BACKGROUND/OBJECTIVES: Dietary habits are known to affect health, including the rate of brain ageing and susceptibility to diseases. This study examines the longitudinal relationship between dietary diversity and hippocampal volume, which is a key structure of memory processing and is known to be impaired in dementia. SUBJECTS/METHODS: Subjects were aged 40-89 years (n = 1683, men: 50.6%) and participated in a 2-year follow-up study of the National Institute for Longevity Sciences-Longitudinal Study of Aging. Dietary intake was calculated from 3-day dietary records, and dietary diversity was determined using the Quantitative Index for Dietary Diversity at baseline. Longitudinal changes in hippocampal and total grey matter volumes were estimated by T1-weighted brain magnetic resonance imaging and FreeSurfer software. Estimated mean brain volume change in relation to dietary diversity score quintiles was assessed by the general linear model, adjusted for age, sex, education, smoking status, alcohol intake, physical activity, and comorbidities. RESULTS: The mean (± standard deviation) % decreases in hippocampal and total grey matter volume during the 2-year follow-up were 1.00% (±2.27%) and 0.78% (±1.83%), respectively. Multivariate-adjusted decreases in total grey matter volume were associated with dietary diversity score (p = 0.065, p for trend = 0.017), and the % decrease in hippocampal volume was more strongly associated with the dietary diversity score: the estimated mean (± standard error) values were 1.31% (±0.12%), 1.07% (±0.12%), 0.98% (±0.12%), 0.81% (±0.12%), and 0.85% (±0.12%), according to dietary diversity quintiles in ascending order (p = 0.030, p for trend = 0.003). CONCLUSIONS: Among community dwellers, increased dietary diversity may be a new nutritional strategy to prevent hippocampal atrophy.

Subtypes of physical frailty and their long-term outcomes: a longitudinal cohort study.

BACKGROUND: Components of physical frailty cluster into subtypes, but it remains unknown how these might be associated with age-related functional declines and multimorbidities. This study aims to investigated associations of physical frailty subtypes with functional declines and multimorbidity in a 10 year longitudinal cohort survey. METHODS: Complementary longitudinal cohort study used group-based multitrajectory modelling to verify whether frailty subtypes discovered in Taiwan are presented in another aging cohort, then investigated associations of these subtypes with cognitive decline and multimorbidity. Participants aged ≥50 years were recruited from the third to sixth waves (May 2002 to July 2010) of the National Institute for Longevity Sciences-Longitudinal Study of Aging, in Japan. People with incomplete data, pre-frail/frail status before their index wave, and those with incomplete data or who died during follow-up, were excluded. Group-based trajectory analysis denoted five established physical frailty criteria as time-varying binary variables in each wave during follow-up. Incident frailty was classified as mobility subtype (weakness/slowness), non-mobility subtype (weight loss/exhaustion), or low physical activity subtype. General linear modelling investigated associations of these frailty subtypes with activities of daily living, digit symbol substitution test (DSST) and Charlson Comorbidity Index (CCI) at 2 year follow-up. RESULTS: We identified four longitudinal trajectories of physical frailty, which corroborated the distinct subtypes we discovered previously. Among 940 eligible participants, 38.0% were robust, 18.4% had mobility subtype frailty, 20.7% non-mobility subtype, and 20.1% low physical activity subtype. People with mobility subtype frailty were older than those with other frailty subtypes or robust status and had higher prevalence of hypertension, diabetes, and heart failure. In the multivariable-adjusted general linear models, mobility-subtype frailty was associated with a significantly lower DSST score (point estimate -2.28, P = 0.03) and higher CCI (point estimate 0.82, P < 0.01) than the other groups. CONCLUSIONS: Mobility-subtype frailty was associated with functional declines and progression of multimorbidity; the long-term effects of physical frailty subtypes deserve further investigation.

Dietary Diversity and All-Cause and Cause-Specific Mortality in Japanese Community-Dwelling Older Adults.

We examined associations between dietary diversity and all-cause and cause-specific mortality in 386 men and 413 women (age range, 60-79 years at baseline) who took part in the National Institute for Longevity Sciences-Longitudinal Study of Aging study from 1997 to 2000. Dietary intake was assessed using three-day dietary records and photographs. The Quantitative Index for Dietary Diversity was used to determine the dietary diversity among thirteen food groups. Dietary diversity score and each food intake were examined by sex-stratified tertiles, and hazard ratios (HR) were calculated to compare the risk for all-cause and cause-specific deaths across tertiles, after controlling for age, sex, body mass index, alcohol intake, smoking status, education, physical activity, and disease history. During a mean follow-up of 15.7 years, 289 subjects (36.2%) died. Compared to the subjects in the lowest tertile, the multivariate-adjusted HR for all-cause and cancer mortality was 0.69 (95% confidence interval (CI): 0.51-0.94) and 0.57 (95% CI: 0.33-0.98), respectively (trend p < 0.05), in subjects in the highest tertile of dietary diversity. There were no significant associations between dietary diversity score and death from cardiovascular or cerebrovascular disease. Eating a variety of foods might contribute to longevity in older Japanese community dwellers.

Green tea and coffee intake and risk of cognitive decline in older adults: the National Institute for Longevity Sciences, Longitudinal Study of Aging.

OBJECTIVE: To examine the association between green tea and coffee intake and cognitive decline in older adults. DESIGN: A prospective cohort study. The average intake of green tea and coffee in the previous year was assessed through a dietitian interview using a dietary questionnaire. A Mini-Mental State Examination (MMSE) was conducted up to six times biennially. Cognitive decline was screened using the MMSE; its incidence was defined as the first time a score of <27 points was obtained in a biennial test from the baseline. Hazard ratios for incidence of cognitive decline were estimated according to the intake of the two beverages using multivariable Cox proportional hazard regression, controlling for sociodemographic and lifestyle factors. SETTING: The National Institute for Longevity Sciences, Longitudinal Study of Aging (NILS-LSA) in Japan. PARTICIPANTS: Men (n 620) and women (n 685), aged 60-85 years, from the NILS-LSA. RESULTS: During a mean of 5·3 (sd 2·9) years of follow-up, 432 incident cases of cognitive decline were observed. Compared with participants who consumed green tea