Low Serum Total Carotenoids and ß-Cryptoxanthin Are Associated with Low Lean Body Mass in Older Community-Dwellers in the National Institute for Longevity Sciences-Longitudinal Study of Aging: A 4-Y Longitudinal Study.

BACKGROUND: Although diets rich in carotenoids are associated with muscle health and a reduced risk of disability, the relationship between carotenoids and low lean body mass has not been fully elucidated. OBJECTIVES: This study aimed to clarify the relationship between serum carotenoid concentrations and low lean body mass over 4 y in older Japanese community-dwellers. METHODS: A total of 750 adults aged ≥60 y participated in the National Institute for Longevity Sciences-Longitudinal Study of Aging. Individuals with a low lean body mass and muscle strength or gait speed at baseline were excluded. Baseline serum α-carotene, ß-carotene, ß-cryptoxanthin, zeaxanthin, lutein, and lycopene were measured. Low lean body mass was defined as appendicular lean mass relative to the measured height (ALM/ht2) of <7.0 kg/m2 in males and <5.4 kg/m2 in females, according to the criteria of the Asian Working Group for Sarcopenia 2019. A generalized estimating equation was used to estimate the odds ratio and 95% confidence interval for low lean body mass according to tertiles of total and individual carotenoids at baseline, adjusted for sex, age, season, follow-up months, education years, economic status, current smoking status, a history of ischemic heart disease, stroke, hypertension, dyslipidemia, diabetes mellitus, and metabolic equivalents. RESULTS: Low serum total carotenoids were associated with low ALM/ht2, and the odds ratios of low ALM/ht2 in the third tertile of total carotenoids were significantly lower than those in the first tertile after adjusting for covariates. The odds ratios of low ALM/ht2 in the third tertile of ß-cryptoxanthin were significantly associated with those in the first tertile after adjusting for covariates (P = 0.03); however, no trend was observed for this relationship. CONCLUSIONS: These findings indicate that low serum total carotenoids and serum ß-cryptoxanthin are associated with low lean body mass in older Japanese community-dwellers.

Global Associations of the Traditional Japanese Diet Score with Hypertension Prevalence and Systolic Blood Pressure from 2009 to 2019: A Cross-Sectional and Longitudinal Ecological Study.

OBJECTIVE: Prevention and improvement of hypertension is one of the most important health issues worldwide. The traditional Japanese diet contributes to the prevention of some non-communicable diseases associated with hypertension. However, whether traditional Japanese dietary patterns are associated with hypertension prevalence and systolic blood pressure (SBP) worldwide remains unknown. In this study, we aimed to investigate whether the traditional Japanese diet score (TJDS) is associated with hypertension prevalence and SBP. METHODS: This cross-sectional and longitudinal ecological study from 2009 to 2019 included 141 countries with a population of at least 1 million. All data used for analysis were obtained from internationally available databases. The TJDS was calculated using country-specific supplies of five foods commonly eaten in the traditional Japanese diet (rice, fish, soybean, vegetables, and egg) and three less commonly eaten foods (wheat, milk, and red meat). Hypertension was defined by SBP ≥140 mmHg, diastolic blood pressure ≥90 mmHg, or use of antihypertensive medications. The mean SBP was >25 age-standardized data. A general linear model was used for the cross-sectional model in 2009, and a linear mixed model was used for the longitudinal analysis from 2009 to 2019. The covariates included gross domestic product, percentage of population aged >65 years, years of education, smoking rate, average body mass index, physical activity, and energy supply. RESULTS: The TJDS was negatively associated with hypertension prevalence (ß ± standard error: -0.861 ± 0.202, p < 0.001) and SBP (ß ± standard error: -0.364 ± 0.154, p < 0.05) in the cross-sectional analysis. The TJDS was significantly negatively associated with hypertension prevalence (ß ± standard error: -0.845 ± 0.200, p < 0.001) and SBP (ß ± standard error: -0.312 ± 0.149, p < 0.05) in the 10-year longitudinal analysis controlled for full covariables. CONCLUSIONS: Traditional Japanese dietary patterns are associated with lower hypertension prevalence and SBP worldwide.

Longitudinal association between muscle and bone loss: Results of US and Japanese cohort studies.

BACKGROUND: Muscle and bone are physiologically interconnected, but joint changes of muscle and bone with aging, and whether the muscle-bone changes are different by sex and by country has been little studied. We examined longitudinal associations of bone mineral density (BMD) and muscle mass or muscle strength in community-dwelling 65 years or older in the United States and Japan. METHODS: The present analytic sample included 1129 women and men from the Baltimore Longitudinal Study of Aging (BLSA) (mean age, 74.5 ± 7.5 years; women, 49.8%) and 1998 women and men from the National Institute for Longevity Sciences-Longitudinal Study of Aging (NILS-LSA) (mean age, 70.0 ± 4.5 years; women, 51.4%). Median follow-up was 4.6 (min-max, 0-15.4) years in the BLSA and 4.0 (min-max, 0-13.4) years in the NILS-LSA. We selected visits at which participants had BMD (whole body, pelvic, femoral neck, trochanter, and Ward's triangle BMDs) and muscle mass [appendicular lean mass, (ALM)] measured by DXA scan. In each bone site, we ran cohort-specific bivariate linear mixed-effects models adjusted for baseline age, sex, body height, body weight, fat mass, education year, and smoking status. Race was an additional adjustment in the BLSA. Additionally, we performed sex-specific analyses. RESULTS: In the BLSA, the rate of change in ALM positively correlated with the rate of change in the whole body (rho = 0.30, P < 0.0001) and pelvic BMD (rho = 0.24, P < 0.0001), but not in trochanter, femoral neck, or Ward's triangle BMD (P > 0.05). In the NILS-LSA, ALM positively correlated with the rate of change in all bone sites (rho ranged from 0.20 to 0.71, P < 0.01). In women, ALM positively correlated with the rate of change in all bone sites in both cohorts (in the NILS-LSA, rho ranged from 0.35 to 0.91, P < 0.01; in the BLSA, rho ranged from 0.26 to 0.56, P < 0.05) except for femoral neck BMD in the BLSA. In men, ALM positively correlated with pelvic, trochanter, and Ward's triangle BMD in the NILS-LSA (rho ranged from 0.45 to 0.68, P < 0.0001), and whole body and trochanter BMD in the BLSA (both, rho = 0.20, P < 0.05). CONCLUSIONS: Muscle loss co-occurred with bone loss in both cohorts, but the association in the NILS-LSA tended to be stronger than in the BLSA, and the association was higher in women than in men, implying that the association may differ by sex and country.

Effects of cigarette smoking and secondhand smoke exposure on physical frailty development among community-dwelling older adults in Japan: Evidence from a 10-year population-based cohort study.

AIM: This study explored longitudinally the relationship between smoking and secondhand smoke and the incidence of physical frailty in community-dwelling Japanese older people. METHODS: Data collected from the National Institute for Longevity Sciences-Longitudinal Study of Aging database from 2002 to 2012 (third to seventh wave) among older adults aged ≥65 years were analyzed. Participants with physical frailty at baseline, as determined by the Cardiovascular Health Study criteria, missing data or who failed to attend follow ups were excluded. Data on current cigarette smoking and secondhand smoke exposure were collected from the third wave results. The generalized estimating equation model was used to examine the longitudinal relationships between smoking, secondhand smoke and subsequent frailty. RESULTS: The final analysis included 540 participants with a mean age of 71.4 years (standard deviation 4.6). The generalized estimating equation analysis showed that, compared with non-smokers, smokers were at significant risk of physical frailty (odds ratio [OR] 2.39, 95% confidence interval [CI] 1.21-4.74) after adjustment for multiple covariates; especially men (OR 3.75, 95% CI 1.76-8.00) and older adults aged ≥75 years (OR 4.12, 95% CI 1.43-11.87). Participants exposed to both smoking and secondhand smoke had a higher risk of physical frailty (OR 3.47, 95% CI 1.56-7.73) than non-smokers without secondhand smoke exposure. Smokers exposed to secondhand smoke were associated with more risk of physical frailty (OR 9.03, 95% CI 2.42-33.77) compared with smokers without secondhand smoke exposure. CONCLUSIONS: Smoking, especially when combined with secondhand smoke exposure, is associated with future physical frailty among older adults. Geriatr Gerontol Int 2024; 24: 142-149.

Implication of grip strength assessment for the management of body weight in disability prevention in older adults.

BACKGROUND: Although body mass index (BMI) and grip strength (GS) are both predictors of disability, their joint effect on predicting incident disability remains uncertain. We examined whether the effect of BMI on incident disability can be modulated by GS in community-dwelling older people in Japan. METHODS: A total of 1486 community-dwellers in Japan (731 men and 755 women, aged 65-82 years) who participated in the 2nd to 7th waves of the National Institute for Longevity Sciences-Longitudinal Study of Aging (NILS-LSA) project, were followed up to 20 years. Twelve subgroups were created according to the intersections of GS (sex-specific tertiles: low, intermediate, and high) and BMI (underweight 1, <18.5; underweight 2, 18.5-<21.5; normal, 21.5-<25.0; and overweight/obese, ≥25.0 kg/m2 ). Incident disability was defined as requiring care need level 1 or higher, as per the long-term care insurance system in Japan. The hazard ratios (HR) and corresponding 95% confidence intervals (CI) of incident disability (the 'high GS-normal BMI' subgroup was used as the reference) were calculated using a multivariable-adjusted Cox proportional hazards model. The model was adjusted for baseline characteristics on sex, participation wave, smoking, depressive symptoms, total physical activity, disease history, education level, residential status, and energy intake. RESULTS: Compared with that for participants in the 'high GS-normal BMI' group, the risk of incident disability was higher for participants in the 'low GS-normal BMI', 'low GS-overweight/obese', 'intermediate GS-underweight 1' and 'intermediate GS-overweight/obese' groups. The multivariable-adjusted HR (95% CI) were 1.72 (1.27-2.32, P value<0.001), 1.81 (1.27-2.58, P value = 0.001), 2.42 (1.35-4.32, P value = 0.003) and 1.53 (1.06-2.20, P value = 0.023), respectively. The results did not change substantially when participants with disability occurring within 1 and 2 years of follow-up were excluded, or when the competing events were death without incident disability or dementia. CONCLUSIONS: The joint effect of BMI and GS was more pronounced in those of normal weight or overweight/obese status and low GS, along with underweight or overweight/obese status and intermediate GS in predicting disability. The lack of observed joint effect for those underweight with low GS was likely due to insufficient sample size. GS consideration is necessary for weight management in older adults, and interventions for individuals who are underweight or overweight/obese with adequate GS need not be prioritized for disability prevention.

Dietary amino acid intake and sleep duration are additively involved in future cognitive decline in Japanese adults aged 60 years or over: a community-based longitudinal study.

BACKGROUND: Sleep duration and amino acid intake are independently associated with cognitive decline. This study aimed to determine the longitudinal association between sleep duration and cognitive impairment incidence and to examine the involvement of diet, particularly amino acid intake, in these associations in community dwellers. METHODS: In this longitudinal study in a community-based setting, we analyzed data from 623 adults aged 60-83 years without cognitive impairment at baseline. Sleep duration was assessed using a self-report questionnaire. Amino acid intake was assessed using 3-day dietary records. Cognitive impairment was defined as a Mini-Mental State Examination score ≤ 27. Participants were classified into short-, moderate-, and long-sleep groups according to baseline sleep duration (≤ 6, 7-8, and > 8 h, respectively). Using moderate sleep as a reference, odds ratios (ORs) and 95% confidence intervals (CIs) of short- and long-sleep for cognitive-impairment incidence were estimated using the generalized estimating equation. Participants were classified according to sex-stratified quartiles (Q) of 19 amino acid intake: Q1 and Q2-Q4 were low- and middle to high-intake groups, respectively. Using middle- to high-intake as a reference, ORs and 95% CIs of low intake for cognitive impairment incidence were estimated using the generalized estimating equation in each sleep-duration group. Follow-up period, sex, age, body mass index, depressive symptoms, education, smoking status, employment status, sleep aids use, physical activity, medical history, and Mini-Mental State Examination score at baseline were covariates. RESULTS: Mean follow-up period was 6.9 ± 2.1 years. Adjusted ORs (95% CIs) for cognitive impairment in short- and long-sleep groups were 0.81 (0.49-1.35, P = 0.423) and 1.41 (1.05-1.87, P = 0.020), respectively. Particularly in long sleepers (i.e., > 8 h), cognitive impairment was significantly associated with low cystine, proline, and serine intake [adjusted ORs (95% CIs) for cognitive impairment were 2.17 (1.15-4.11, P = 0.017), 1.86 (1.07-3.23, P = 0.027), and 2.21 (1.14-4.29, P = 0.019), respectively]. CONCLUSIONS: Community-dwelling adults aged ≥ 60 years who sleep longer are more likely to have cognitive decline, and attention should be paid to the low cystine, proline, and serine intake.

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.

Association between short-chain fatty acid intake and development of muscle strength loss among community-dwelling older Japanese adults.

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 <28 kg for men and <18 kg for women) at baseline. Baseline nutrient intakes were assessed with a 3-day dietary record. A generalized estimating equation was employed to estimate the odds ratio (OR) and 95 % confidence intervals (CIs) for low muscle strength per 1 standard deviation (SD) increase in the intake of SCFAs and other nutrients at baseline (adjusted for sex, age, follow-up time, baseline grip strength, physical activity, smoking, family income, education, and disease histories). RESULTS: The mean (SD) follow-up time and number were 7.8 (3.2) years and 3.2 (1.0) times, respectively. Approximately 8.1 % of the participants exhibited muscle strength loss in at least one follow-up assessment. The multivariate-adjusted OR (95 % CIs) was 0.77 (0.63-0.93) for each 1-SD increase in SCFA intake (268 mg/day), and the ORs for the highest through the lowest tertiles of SCFA intake were 1.00 (reference), 1.44 (0.95-2.17), and 1.83 (1.20-2.78), respectively (trend p = 0.005). The results remained significant after multivariate adjusting for energy or fat intake. CONCLUSION: Dietary intake of SCFAs may prevent muscle strength decline in community-dwelling older adults.

Serum levels of dehydroepiandrosterone sulfate are associated with a lower risk of mobility-subtype frailty in older Japanese community-dwellers.

PURPOSE: Previous studies suggest that lower serum levels of dehydroepiandrosterone sulfate (DHEA-S) are associated with physical frailty. Associations with subtypes of physical frailty have not been studied. This study aimed to investigate associations between serum DHEA-S levels and physical frailty and its subtypes in older Japanese community-dwellers using panel data. METHODS: This study was conducted within the National Institute for Longevity Sciences-Longitudinal Study of Aging (NILS-LSA). Repeated measurement data were collected from 1,886 older community-dwellers (60-91 years). Frailty was identified according to modified Cardiovascular Health Study criteria (weight loss, weakness, slowness, exhaustion, low physical activity) and was classified into following subtypes: mobility (weakness/slowness), non-mobility (weight loss/exhaustion), and low physical activity. Associations with serum DHEA-S (sex-specific tertiles [T1-T3]) were estimated by random-effects logistic regression models adjusting for age, sex, education, disease history (stroke, hypertension, heart disease, diabetes), smoking status, depressive symptoms, and survey wave. RESULTS: We found an average prevalence of 6.0% for frailty (mobility subtype, 7.0%; non-mobility subtype, 34.8%; low physical activity subtype, 9.4%) across survey waves. Mean (SD) sex-specific DHEA-S levels (µg/dL) at T1, T2, and T3 were 46.8 (20.8), 88.7 (28.4), and 158.0 (58.9), respectively. Compared with T1, the adjusted ORs (95% CIs) for frailty were 0.69 (0.44, 1.08) for T2 and 0.50 (0.30, 0.83) for T3 (P trend = 0.007). The corresponding values for mobility subtype were 0.80 (0.51, 1.24) for T2 and 0.55 (0.33, 0.90) for T3. CONCLUSION: Higher serum DHEA-S levels were associated with lower risk of frailty, especially mobility-subtype frailty, in older community-dwellers.

Global Association between Traditional Japanese Diet Score and All-Cause, Cardiovascular Disease, and Total Cancer Mortality: A Cross-Sectional and Longitudinal Ecological Study.

OBJECTIVE: Studies conducted on Japanese people have suggested that a traditional Japanese diet contributes to good health, longevity, and protection against several non-communicable diseases. However, it is unknown whether traditional Japanese dietary patterns are associated with all-cause mortality, cardiovascular disease, and cancer mortality globally. The purpose of this cross-sectional and longitudinal ecological study is to clarify the global association between the traditional Japanese diet score (TJDS) and all-cause, cardiovascular disease, and total cancer mortality. METHODS: Data on food supply and all-cause mortality, cardiovascular disease mortality, total cancer mortality, and covariables by country were obtained from a relevant internationally available database. TJDS by country was calculated from eight food groups and the total score ranged from -8 to 8, with higher scores indicating greater adherence to a traditional Japanese diet. We evaluated the cross-sectional and 10-year longitudinal association between TJDS and all-cause, cardiovascular disease, and total cancer mortality using 2009 as the baseline in 142 countries with populations of more than one million. A cross-sectional analysis and a longitudinal analysis were performed using three general linear models or three linear mixed models with different covariables. RESULTS: In cross-sectional models controlled for fully-adjusted covariables, TJDS was negatively associated with all-cause mortality (ß ± standard error; -43.819 ± 11.741, p < 0.001), cardiovascular disease mortality (-22.395 ± 4.638, p < 0.001), and total cancer mortality (-3.893 ± 1.048, p < 0.001). In 10-year longitudinal models controlled for fully-adjusted covariables, TJDS was significantly negatively associated with all-cause mortality (-31.563 ± 7.695, p < 0.001), cardiovascular disease mortality (-16.249 ± 4.054, p < 0.001), and total cancer mortality (-3.499 ± 0.867, p < 0.001). CONCLUSIONS: This cross-sectional and longitudinal ecological study suggests that the traditional Japanese diet is associated with lower all-cause mortality, cardiovascular disease mortality, and total cancer mortality, worldwide.

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.

Basic lifestyle habits and volume change in total gray matter among community dwelling middle-aged and older Japanese adults.

The brain controls human behavior, and the gray matter is the main resource of neuronal cells. We examined the longitudinal relationship between six basic lifestyle habits (diet, exercise, sleep, alcohol consumption, smoking, and social activity including employment) and total gray matter volume in community-dwelling adults in Japan. This two-year follow-up study with data derived from the National Institute for Longevity Sciences, Longitudinal Study of Aging, Aichi, Japan, included adults aged 40-87 years (n = 1665, men: 51%). Lifestyle habits were assessed at baseline (2008-2010) using self-reported questionnaires and three-day dietary records. Total gray matter volume at baseline and after two years was estimated using T1-weighted brain magnetic resonance imaging and FreeSurfer software. The association between each lifestyle factor, the total number of healthy lifestyle habits, and gray matter volume change was determined via a multiple linear regression analysis adjusting for baseline age, total gray matter volume, and other confounders. The mean ± standard deviation decrease in total gray matter volume during the two-year follow-up period was 0.94 ± 1.86% in men and 0.61 ± 2.27% in women. In the multiple regression analysis, volume loss in total gray matter positively correlated with male smoking, while it was negatively correlated with male social activity and employment, female dietary diversity, and the total number of healthy lifestyle habits (standardized beta coefficient; -0.061 in men [p = 0.07], -0.113 in women [p < 0.05]). Therefore, engaging in social activities, non-smoking, a diverse diet, or adopting one healthy lifestyle habit may help prevent gray matter volume loss.

Hemoglobin concentration is associated with the hippocampal volume in community-dwelling adults.

BACKGROUND: This study examined whether the hemoglobin concentration is correlated with the hippocampal volume using voxel-based morphometry (VBM). METHODS: This cross-sectional study included 1923 community dwellers, aged 40‒89 years, from the sixth wave of the National Institute for Longevity Sciences, Longitudinal Study of Aging. The hemoglobin levels were determined through blood examination. The regional cortical volumes were evaluated using three-dimensional T1-weighted magnetic resonance images. Following preprocessing with a statistical parametric mapping software, a VBM analysis of covariance design was implemented to identify the regional gray matter volumes related to hemoglobin concentration, while adjusting for age, sex, education, body mass index, depressive symptoms, alcohol consumption status, smoking status, medical history, and the estimated glomerular filtration rate. RESULTS: VBM analysis revealed a significantly positive correlation between the hemoglobin concentration and gray matter volume in the bilateral anterior hippocampus and the amygdala clusters as well as in the cingulate and middle temporal gyri, cerebellum, and superior sagittal and transverse sinuses. CONCLUSIONS: The hemoglobin concentration could be positively associated with the hippocampal volume among community-dwelling middle-aged and older adults, which highlights the importance of monitoring the hemoglobin concentration in older adults to decrease the possibility of neurodegeneration.

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.

Prevalence of usage of hearing aids and its association with cognitive impairment in Japanese community-dwelling elders with hearing loss.

OBJECTIVE: Hearing loss is a risk factor for cognitive impairment, and the use of a hearing aid (HA) may prevent cognitive decline alongside hearing loss. We aimed to elucidate the prevalence of self-reported HA usage in Japanese community-dwelling elders with hearing loss, and the effect of hearing and HA on cognitive impairment. METHODS: A total of 1193 participants, who had audiometric defined hearing loss and were aged 60 years or over, had their cumulative 3260 observations followed up for 10 years from a large cohort of a Japanese study. Association between hearing (pure-tone average threshold level at 500, 1000, 2000, and 4000 Hz from the better hearing ear: PTABHE) and HA usage with cognitive impairment (total score of Mini-Mental State Estimation was under 27 or diagnosed as dementia) was analyzed using generalized estimating equations. RESULTS: The HA usage rate of the 1193 community-dwelling elders with hearing loss was 6% during the first involvement. The majority (59.2%) of HA users always used an HA. HA usage rate was 0.7% for the mild hearing loss group and 32.4% for the moderate or greater hearing loss group in the latest participating wave. PTABHE was significantly associated with cognitive impairment (odds ratio for every 10 dB 1.36; 95% CI 1.21-1.53, p<0.0001) after adjusting for age, sex, education, depressed mood, smoking status, alcohol intake, income, activity, obesity, histories of hypertension, dyslipidemia, ischemic heart disease, diabetes, stroke, ear disease, and occupational noise exposure. PTABHE was also significantly associated with cognitive impairment in the mild hearing loss group (odds ratio for every 10 dB 1.34; 95% CI 1.05-1.72, p = 0.020) and moderate hearing loss group (odds ratio for every 10 dB 1.82; 95% CI 1.27-2.61, p = 0.001). HA use showed a significant suppressive effect on cognitive impairment in those with moderate hearing loss who always use an HA (odds ratio 0.54; 95% CI 0.30-1.00, p = 0.049). CONCLUSION: The prevalence of HA usage among Japanese community-dwelling elders with hearing loss is consistent, at around 10%. The hearing level remained a primary risk factor for cognitive impairment among elders with hearing loss after adjusting for several confounding factors. Regular HA use may have a protective effect on cognitive impairment in those with moderate hearing loss.

[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.

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.

Global relationship between Mediterranean diet and the incidence and mortality of ischaemic heart disease.

BACKGROUND: The purpose of this study was to clarify the global relationship between the Mediterranean diet score (MDS) and country-wise incidence and mortality of ischaemic heart disease (IHD) using an international database. METHODS: We used population data from a global longitudinal database covering 137 countries with a population of over one million. MDS were evaluated based on the total score of the nine foods that comprise the Mediterranean diet. The incidence and mortality of IHD by country was derived from the Global Burden of Disease (GBD) database. Average food (g/day/capita) and energy supply (kcal/day/capita) by country, excluding loss between production and household, were obtained from the Food and Agriculture Organization of the United Nations Statistics Division database. Data from the GBD database were used for body mass index, current smoking rates, physical activity, years of education and percentage of the Muslim population. We identified the percentage of the population over 65 years of age (aging rate) and gross domestic product per capita (US$/capita) using the World Bank database. A linear mixed-effect model was used for evaluating the effects of MDS on incidence and mortality of IHD controlled for socioeconomic and lifestyle variables. RESULTS: Analysis showed that MDS was significantly associated with IHD incidence after controlling for covariates (-1.01 ± 0.27, P < 0.001). Similarly, there was a significant association between MDS and IHD-related mortality after controlling for covariates (-0.73 ± 0.34, P < 0.05). CONCLUSION: Analysis of 27 years of data suggests that a Mediterranean diet might have a preventive effect on IHD.