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Objectives: Variability in intrinsic capacity (IC) changes among community-dwelling older adults and their effect on health outcomes remain understudied. We examined the variability in IC trajectories and their impact on higher-level functional capacity (HLFC), life satisfaction, and self-esteem. Design: Longitudinal study. Setting: Data from the second to seventh waves (2000–2012) of the National Institute for Longevity Sciences–Longitudinal Study of Aging project. Participants: 934 community dwellers (aged ≥60). Measurements: We used group-based multi-trajectory modeling to obtain IC trajectories across six domains: cognition, locomotion, vitality, vision, hearing, and psychological well-being. We employed multivariable regression to investigate the associations between IC trajectories and a decline in HLFC (assessed using the Tokyo Metropolitan Institute of Gerontology Index of Competence [TMIG-IC]; baseline TMIG-IC - follow-up TMIG-IC ≥ 2; logistic regression model), life satisfaction (assessed using the Life Satisfaction Index-K [LSI-K]; linear mixed model), and self-esteem (assessed using the Rosenberg Self-Esteem Scale [RSES]; linear mixed model). Results: We identified four IC trajectories: the “healthy aging group” (63.7%), the “hearing decline group” (15.1%), the “vision and cognitive decline group” (12.7%), and the “comprehensive deterioration group” (8.5%). Compared to the healthy aging group, the vision and cognitive decline group and the comprehensive deterioration group displayed a significantly greater risk of a decline in the TMIG-IC score (multivariable-adjusted odds ratio [aOR], 95% confidence interval [CI] = 2.05 [1.11, 3.79], 2.74 [1.41, 5.30], respectively), the LSI-K score (multivariable-adjusted β [standard error] = −0.46 [0.08], −0.52 [0.10], respectively), and the RSES score (multivariable-adjusted β [standard error] = −0.85 [0.16], −0.66 [0.20], respectively). The “hearing decline group” did not show a significantly increased risk for these outcomes. Conclusion: Older adults with different IC trajectories may differ in HLFC, life satisfaction, and self-esteem. Public health officials should be aware of this and provide targeted interventions.

Background: Frailty transition is common, and increased physical activity can prevent it. An objective assessment of physical activity could eliminate bias and provide more precise information on the association between frailty transitions and physical activity. Objectives: This study aimed to examine the association between objective physical activity and frailty transition in community-dwelling prefrail Japanese older adults. Design: This is a retrospective cohort study based on the National Institute for Longevity Science-Longitudinal Study of Aging data. Participants: A total of 387 community-dwelling older adults with prefrailty were enrolled (mean age 72.0 years). Measurements: Frailty was assessed using modified components of the Cardiovascular Health Study criteria, and frailty statuses were reassessed two years later. The frailty transitions were categorized into three groups: deterioration, persistence, and reversal. Participants wore a uniaxial accelerometer to assess the physical activities. Differences in baseline characteristics according to frailty transitions were assessed. To compare the baseline objective physical activities based on frailty transition, a general linear model and a logistic regression model were used. Results: Among the 387 participants, 40 (10.3%) deteriorated to frailty, 97 (25.0%) reversed to robust, and the majority (n = 250, 64.6%) remained prefrail after a 2-year follow-up. Using the general linear model, after adjusting for other factors, total energy expenditure (TEE) in the reversal group was significantly higher than that in the deterioration and persistence groups. No differences in TEE were observed between the persistence and deterioration groups. No significant differences existed in the numbers of daily steps, exercise energy expenditure (EEE) and physical activity with different intensity among these three groups. The logistic model also showed a significant association between TEE and the reversal of frailty. Conclusion: Frailty transitions were common in the Japanese prefrail population. This study showed that a higher TEE was positively associated with frailty reversal in prefrail older adults. Promoting proactive programs for older adults to increase physical activity could help them stay healthy and prevent frailty deterioration.

Background: Several circulating microRNAs (miRNAs) in the blood are indicators of chronic diseases, but their association with multimorbidity burden is unknown. The aim of this study was to assess the association of plasma levels of circulating miR-323–3p and miR-135–3p with age, cognitive performance, and number of comorbidities in middle-aged and older individuals. Methods: Data from 295 community dwellers (≥40 years) who participated in the second wave (2000‒2002) of the National Institute for Longevity Sciences-Longitudinal Study of Aging in Japan were analyzed. miRNAs were isolated from the plasma, and miR-323–3p and miR-135–3p levels were measured using quantitative reverse-transcription polymerase chain reaction and normalized, with miR-16 as an endogenous reference gene. Cognitive performance was assessed using the Information and Similarities subtests and the Digit Symbol Substitution Test of the Wechsler Adult Intelligence Scale-Revised Short Form (WAIS-R-SF). Correlation tests and multivariate general linear regression analyses were performed to examine the relationship among circulating miRNA levels, burden of multimorbidity, and cognitive performance. Results: The mean age of the participants was 59.15 ± 10.26 years. Pearson's correlation analysis revealed that the miR-323–3p level positively correlated with age and number of comorbidities but negatively correlated with WAIS-R-SF subtest performance. In men, miR-323–3p level negatively correlated with the performance of all three WAIS-R-SF subtests. The general linear regression analysis showed that the miR-323–3p level increased in participants with four comorbidities compared with those with one comorbidity. Conclusion: Circulating miR-323–3p level is associated with the burden of multimorbidity and decreased cognitive performance in middle-aged and older adults.

Objectives: This study aimed to investigate the association between abdominal adiposity and change in cognitive function in community-dwelling older adults. Design, Setting, and Participants: This longitudinal study included older adults aged ≥60 years without cognitive impairment who participated in the National Institute for Longevity Sciences – Longitudinal Study of Aging. Measurements: Cognitive function was evaluated biennially using the Mini-Mental State Examination (MMSE) over 10 years. Waist circumference (WC) was measured at the naval level, and subcutaneous fat area (SFA) and visceral fat area (VFA) were assessed using baseline computed tomography scans. WC, SFA, and VFA areas were stratified into sex-adjusted tertiles. A linear mixed model was applied separately for men and women. Results: This study included 873 older adults. In men, the groups with the highest levels of WC, SFA, and VFA exhibited a greater decline in MMSE score than the groups with the lowest levels (β [95% confidence interval]: WC, –0.12 [–0.23 to –0.01]; SFA, –0.13 [–0.24 to –0.02]; VFA, –0.11 [–0.22 to –0.01]). In women, the group with the highest level of WC and SFA showed a greater decline in MMSE score than the group with the lowest level (WC, –0.12 [–0.25 to –0.01]; SFA, –0.18 [–0.30 to –0.06]), but VFA was not associated with cognitive decline. Conclusion: Higher WC, SFA, and VFA in men and higher WC and SFA in women were identified as risk factors for cognitive decline in later life, suggesting that abdominal adiposity involved in cognitive decline may differ according to sex.

Background: Short-chain fatty acids (SCFAs) have been suggested to be associated with skeletal muscle mass maintenance. However, the role of dietary SCFAs in preserving muscle strength in the older population remains unclear. Objectives: To clarify the longitudinal association between the dietary intake of SCFAs and the development of low muscle strength in older community dwellers. Methods: Data were obtained from the National Institute for Longevity Sciences-Longitudinal Study of Aging cohort. The participants included 441 men and 382 women who participated in the baseline survey (the fifth wave, between 2006 and 2008) and at least one follow-up examination (sixth to ninth waves, between 2008 and 2022) and were ≥60 years old and did not have low muscle strength (defined as a grip strength of

Background and aims: Carriers of the apolipoprotein E ε4 allele (APOEɛ4) have an increased risk of developing dementia (e.g., Alzheimer's disease). However, it is less clear whether the APOEɛ4 might also be involved in cognitive aging among the non-clinical population of older adults. While some studies have suggested that the APOEɛ4 is related to accelerated cognitive decline in the normal aging process, others have failed to provide compelling evidence of such an impact. Notably, these discrepancies may depend on methodological shortcomings, including short time spans, few assessments, and small sample sizes. The present study overcomes the above limitations and aims to clarify the impact of the APOEɛ4 genotype on long-term longitudinal changes in cognitive functions in middle-aged and older adults in Japan. Methods and results: The data were retrieved from the National Institute for Longevity Sciences-Longitudinal Study of Aging (NILS-LSA) survey (N = 1832; 40 to 79 years of age at baseline). The participants were tested over nine waves covering a period of approximately 20 years. Latent Growth Curve (LGC) modeling was employed to test the impact of the interaction between APOEɛ4 status and age on several cognitive functions. Four tests of the WAIS-R were administered: Information, Similarities, Picture completion, and Digit Symbol Substitution Test (DSST). The results showed that the APOEɛ4 carriers experienced a more pronounced decline in the DSST (p = 0.001) and Similarities (p = 0.022) tests. A similar tendency was found in the Information test (p = 0.034). By contrast, no effect was found in the Picture completion test (p = 0.563). Conclusions: APOEɛ4 carriers seem to exhibit a steeper cognitive decline, which becomes apparent in old age. This effect is more robust in fluid cognitive skills (DSST) than crystallized cognitive skills (Information and Similarities). Overall, the APOEɛ4 genotype may be a significant risk factor in normal (i.e., non-clinical) cognitive aging.

This study aimed to clarify the effects of the accumulation of 8 modifiable practices related to health, including smoking, alcohol drinking, physical activity, sleeping hours, body mass index, dietary diversity, ikigai (life worth living), and health checkup status, on higher-level functional capacity decline among Japanese community dwellers. Data were derived from the National Institute for Longevity Sciences - Longitudinal Study of Aging. Subjects comprised 1269 men and women aged 40 to 79 years at baseline (1997–2000) who participated in a follow-up postal survey (2013). Higher-level functional capacity was measured using the Tokyo Metropolitan Institute of Gerontology Index of Competence (total score and 3 subscales: instrumental self-maintenance, intellectual activity, and social role). The odds ratio (OR) and 95% confidence interval (CI) for a decline in higher-level functional capacity in the follow-up study according to the total number of healthy practices were analyzed using the lowest category as a reference. Multivariate adjusted ORs (95% CIs) for the total score of higher-level functional capacity, which declined according to the total number of healthy practices (0–4, 5–6, 7–8 groups) were 1.00 (reference), 0.63 (0.44–0.92), and 0.54 (0.31–0.94). For the score of social role decline, multivariate adjusted ORs (95% CIs) were 1.00 (reference), 0.62 (0.40–0.97), and 0.46 (0.23–0.90), respectively (P for trend = 0.04). Having more modifiable healthy practices, especially in social roles, may protect against a decline in higher-level functional capacity among middle-aged and elderly community dwellers in Japan.