Usefulness of the serum creatinine/cystatin C ratio as a blood biomarker for sarcopenia components among age groups in community-dwelling older people: The SONIC study.

AIM: The serum creatinine/cystatin C ratio (CCR) or sarcopenia index is considered a useful marker of muscle mass. However, its usefulness in late-stage older adults remains unclear. We aimed to determine the usefulness of CCR as an indicator of sarcopenia in community-dwelling Japanese adults aged >75 years. METHODS: Our study recruited participants aged 70, 80, and 90 ± 1 years during the baseline years, and included a 3-year follow-up in the Septuagenarians, Octogenarians, Nonagenarians, Investigation with Centenarians study. From 2015 to 2018, 955 participants were eligible: 367 in their 70s, 304 in their 80s, and 284 in their 90s. The diagnostic components of sarcopenia, including "low muscle mass, plus low muscle strength, and/or low physical performance," were evaluated using the bioelectrical impedance analysis-measured skeletal muscle mass index (SMI), handgrip strength, and short physical performance battery (SPPB) score, respectively, in accordance with the Asia Working Group for Sarcopenia 2019 criteria. Separate analyses were performed between each component and CCR, adjusting for sex, body mass index, and other blood biomarkers in each group. RESULTS: The relationship between CCR and sarcopenia components was significant for handgrip strength (ß = 0.21, 0.13, 0.19, and P < 0.0001, =0.0088, <0.0001, for the 70s, 80s, and 90s age groups, respectively); however, it was limited for SMI (ß = 0.14; P = 0.0022, only for the 90s) and not significant for the SPPB score. CONCLUSION: CCR is a limited indicator of sarcopenia in late-stage older adults. Although its association with muscle strength was significant, its relationship with muscle mass and physical performance was less pronounced. Geriatr Gerontol Int 2024; ••: ••-••.

Exploring the association between number of teeth, food intake, and cognitive function: A 9-year longitudinal study.

OBJECTIVES: This study aimed to investigate the association between the number of teeth, food intake, and cognitive function in Japanese community-dwelling older adults. METHODS: This 9-year longitudinal study included a total of 293 analyzable participants who participated in baseline and follow-up surveys. Dental status (number of teeth and periodontal pocket depth), dietary assessment using the brief-type self-administered diet history questionnaire, cognitive function, and the following confounding factors were evaluated: educational level, financial satisfaction, living situation, smoking and drinking habits, history of chronic diseases, apolipoprotein E-ε4 carrier, body mass index, handgrip strength, instrumental activities of daily living, and depressive symptomatology. The Japanese version of the Montreal Cognitive Assessment was used to evaluate cognitive function. A multinomial logistic regression analysis for the intake level of each food categorized into three groups (low, moderate, high), and a generalized estimating equation (GEE) for cognitive function over nine years were performed. RESULTS: After controlling for confounding factors, the number of teeth was shown to be associated with the intake of green-yellow vegetables and meat. Furthermore, the GEE indicated that the lowest quartile of intake of green-yellow vegetables significantly associated with lower cognitive function (unstandardized regression coefficient [B] = -0.96, 95 % confidence interval [CI]: -1.72 to -0.20), and the lowest quartile of intake of meat significantly associated with lower cognitive function (B = -1.42, 95 % CI: -2.27 to -0.58). CONCLUSIONS: The intake of green and yellow vegetables and meat, which is influenced by the number of teeth, was associated with cognitive function in Japanese community-dwelling older adults. CLINICAL SIGNIFICANCE: There are few studies that have examined the association between oral health, food intake, and cognitive function. This 9-year longitudinal study suggests that it is important to maintain natural teeth to enable the functional means to consume green-yellow vegetables and meat, and thereby help maintain cognitive function.

Moderating effect of age on the relationship between physical health loss and emotional distress post-acute care in Japanese older hospitalized patients.

BACKGROUND: At present, there are no consistent findings regarding the association between physical health loss and mental health in older adults. Some studies have shown that physical health loss is a risk factor for worsening of mental health. Other studies revealed that declining physical health does not worsen mental health. This study aimed to clarify whether the relationship between physical health loss and emotional distress varies with age in older inpatients post receiving acute care. METHODS: Data for this study were collected from 590 hospitalized patients aged ≥ 65 years immediately after their transfer from an acute care ward to a community-based integrated care ward. Emotional distress, post-acute care physical function, and cognitive function were assessed using established questionnaires and observations, whereas preadmission physical function was assessed by the family members of the patients. After conducting a one-way analysis of variance (ANOVA) and correlation analysis by age group for the main variables, a hierarchical multiple regression analysis was conducted with emotional distress as the dependent variable, physical function as the independent variable, age as the moderator variable, and cognitive and preadmission physical function as control variables. RESULTS: The mean GDS-15 score was found to be 6.7 ± 3.8. Emotional distress showed a significant negative correlation with physical function in younger age groups (65-79 and 80-84 years); however, no such association was found in older age groups (85-89, and ≥ 90 years). Age moderated the association between physical function and emotional distress. Poor physical function was associated with higher emotional distress in the younger patients; however, no such association was observed in the older patients. CONCLUSIONS: Age has a moderating effect on the relationship between physical health loss and increased emotional distress in older inpatients after acute care. It was suggested that even with the same degree of physical health loss, mental damage differed depending on age, with older patients experiencing less damage.

Effect of number of medications on the risk of falls among community-dwelling older adults: A 3-year follow-up of the SONIC study.

AIM: This study examined the association between the number of prescribed medications and falls among community-dwelling older adults. METHODS: We conducted a geriatric comprehensive health-checkup on community-dwelling adults aged 69-91 years who participated in the Septuagenarians, Octogenarians, and Nonagenarians Investigation with Centenarians study. The final analysis of this study included 1,076 participants with complete data. The participants were divided into four groups based on the number of medications at baseline: 0, 1, 2-4, and ≥5. At the 3-year follow-up, the participants were asked whether they had fallen in the past year. Multivariable logistic regression analysis was performed to assess the relationship between the number of medications taken and falls after adjusting for confounding factors. RESULTS: The prevalence rates of falls were 10.5%, 18.2%, 18.3%, and 19.8% in the no-medication, one-medication, comedication, and polypharmacy groups, respectively. In the one-medication prescription group, 59% of prescriptions were for fall-risk-increasing drugs (FRID). Multivariable analysis showed a significantly higher incidence of falls in the one-medication group (adjusted odds ratio [OR], 1.91; 95% confidence interval [CI], 1.04-3.54), co-medication (OR, 1.89; 95% CI, 1.09-3.29), and polypharmacy groups (OR, 1.94; 95% CI, 1.09-3.45) than in the no-medication group. CONCLUSIONS: The study showed that polypharmacy, as well as just taking one medication, can affect the occurrence of falls. This suggests that in addition to the number of medications and polypharmacy, the type of medication, such as FRID, affects the risk of falls. Therefore, pharmacotherapy should consider the risk of falls in older adults when prescribing medications. Geriatr Gerontol Int 2024; 24: 306-310.

Factors related to subjective evaluation of difficulty in chewing among community-dwelling older adults.

AIM: Awareness of difficulty chewing may limit the diversity of food intake in older adults. However, few studies have clarified which factors are related to subjective difficulty in chewing. The aim was to identify factors related to subjective difficulty in chewing in 70- and 80-year-old Japanese older adults. METHODS: A total of 1680 participants (792 men, 888 women) were surveyed. Difficulty in chewing was assessed with questionnaires regarding food intake, such as rice, apples, beef, and hard rice crackers. The participants were classified into two groups, the "with difficulty" group (participants who answered "cannot eat," "can eat with difficulty," and "can eat if small") and the "without difficulty" group (participants who answered "can eat without problems"), according to their answers to questionnaires for each food. A logistic regression analysis with subjective difficulty in chewing as the dependent variable was performed for each food. RESULTS: Subjective difficulty in chewing was associated with age, occlusal force, and depression for rice; age, number of remaining teeth, occlusal force, and depression for apples; number of remaining teeth, occlusal force, and depression for beef; and number of remaining teeth and occlusal force for hard rice crackers. CONCLUSIONS: Age, number of remaining teeth, and occlusal force, as well as depression, might be related to subjective evaluation of difficulty chewing in community-dwelling Japanese older adults. Geriatr Gerontol Int 2024; 24: 327-333.

Association between prior-night sleep and next-day fatigue in older adults: a daily diary study.

BACKGROUND: Fatigue is known as an element of frailty. Sleep problems (e.g., short sleep duration and low sleep quality) can increase fatigue, but the day-to-day relationship between sleep and fatigue has not been studied well in older adults. Using a daily diary method, this study examined the within- and between-person associations between sleep and fatigue in older adults. METHODS: The study recruited 56 Japanese community dwellers (age: 82-86 years; female: 37.5%). Participants responded to a daily diary questionnaire at the end of each day. Over seven days, time in bed and satisfaction were measured after waking up, whereas fatigue was assessed before going to bed. We included person-level covariates (demographic factors, and physical and mental health) and day-level covariates (time in study, and positive and negative emotions). Multilevel models were estimated to examine within- and between-person associations. RESULTS: At the within-person level, on days following short and long time in bed and days following low levels of sleep satisfaction, individuals felt higher levels of fatigue compared with usual days. At the between-person level, no statistically significant differences in fatigue were observed between individuals with long and short time in bed. CONCLUSIONS: The findings suggest that prior-day sleep is associated with next-day fatigue in older adults. Long and short sleep duration and low sleep quality can lead to fatigue. Considering that sleep is a modifiable health behavior, appropriate management of sleep behavior may reduce fatigue.

The relationship between changes in occlusal support and masticatory performance using 6-year longitudinal data from the SONIC study.

OBJECTIVES: Reduced occlusal support is thought to be related to a decline in masticatory performance. However, previous research in this field was based on cross-sectional studies. In this study, we conducted a 6-year longitudinal observation of older adults living in the community and examined the associations of changes in occlusal support with masticatory performance. METHODS: Of the 864 participants aged 72-74 years in the SONIC study, 488 who were followed up (median follow-up period 5.92 years) and had no missing data were included in this study. Participants were divided into three groups according to the number of occlusal support zones in the posterior area: Complete occlusion (four zones), Reduced occlusion (one to three zones), and Collapsed occlusion (no occlusal support zone). Longitudinal analysis of the relationship between occlusal support and masticatory performance was undertaken with linear mixed-effects models. RESULTS: Sex, occlusal force, number of unreplaced missing teeth, aging, and occlusal support change were significantly related to masticatory performance. Furthermore, the interaction term between change in occlusal support and aging was a significant explanatory variable for the decline in masticatory performance. The interaction was strongest in the group that changed from Complete or Reduced occlusion to Collapsed occlusion. This result indicates that the loss of occlusal support is a major factor contributing to declining masticatory performance. CONCLUSIONS: The decline of occlusal support was greatly associated with the deterioration of masticatory performance. Our results suggest that older adults need to prevent the collapse of posterior occlusal support to maintain their masticatory performance. CLINICAL SIGNIFICANCE: Occlusal support is important for preserving masticatory performance in older adults. Preventing the loss of molars and retaining occlusal support may contribute to maintaining food intake diversity and nutritional status, thereby improving quality of life. Dental professionals need to carefully examine dental status to assess the risk of occlusal collapse.

Age Group Differences in the Association Between Sleep Status and Frailty Among Community-Dwelling Older Adults: The SONIC Study.

Objective: We aimed to determine whether the association of sleep status with frailty differs between age groups of older adults. Method: This cross-sectional study was part of the observational Septuagenarians, Octogenarians, Nonagenarians Investigation with Centenarians (SONIC) study. Subjects were community-dwelling older adults in their 70s and 80s. Frailty was evaluated using the Japanese version of the Cardiovascular Health Study criteria (J-CHS). Pittsburgh Sleep Quality Index (PSQI) was used to assess sleep status. Poor sleep quality was defined as a PSQI global score ≥6. Sleep duration was categorized as short (<6 hr), normal (6-8), and long (>8). We performed multivariable logistic regression to investigate the association between sleep status and frailty separately for each age group adjusted for multiple covariates. Results: In those in their 70s, long sleep duration and sleep medication use were independently associated with frailty. In those in their 80s, poor sleep quality was independently associated with frailty. Conclusions: The association between sleep status and frailty was different between age groups. The findings underscore the importance of incorporating the evaluation of sleep quantity and non-pharmacological therapies in those in their 70s and the evaluation of sleep quality in those in their 80s to help prevent the onset of frailty.

Relationship between the number of teeth, occlusal force, occlusal contact area, and dietary hardness in older Japanese adults: The SONIC study.

PURPOSE: Individuals with impaired masticatory function tend to prefer soft foods, which results in decreased masticatory muscle activity. This study examined the association between the oral condition (number of teeth, occlusal force, and occlusal contact area) and dietary hardness using a daily dietary questionnaire. METHODS: This cross-sectional study evaluated 1841 participants aged 69-71 and 79-81 years. Registered dentists examined the number of teeth, occlusal force, and occlusal contact area. Dietary hardness was defined as the estimated masticatory muscle activity required for a habitual diet. Habitual diet during the preceding month was assessed using a brief self-administered diet history questionnaire. Confounding factors, such as age, sex, socioeconomic status, smoking habits, history of chronic diseases (hypertension, hyperlipidemia, and diabetes), and cognitive function were also evaluated. Multivariate linear regression analyses were performed to assess the association between dietary hardness and each oral condition. RESULTS: Occlusal force (standardized regression coefficients [ß]=0.08, P < 0.01) and occlusal contact area (ß=0.06, P < 0.01) were significantly associated with dietary hardness after adjusting for the confounding factors. Number of teeth was not significantly associated with dietary hardness. In addition, the associations between dietary hardness, sex, and a history of diabetes were stronger than those between dietary hardness and oral factors. CONCLUSIONS: Occlusal force and contact area were significantly associated with dietary hardness as estimated from the masticatory muscle activity using a daily diet questionnaire.

Factors associated with weight loss by age among community-dwelling older people.

BACKGROUND: Factors associated with weight loss in community-dwelling older people have been reported in several studies, but few studies have examined factors associated with weight loss by age groups. The purpose of this study was to clarify factors associated with weight loss by age in community-dwelling older people through a longitudinal study. METHODS: Participants in the SONIC study (Longitudinal Epidemiological Study of the Elderly) were community-dwelling people aged 70 or older. The participants were divided into two groups: 5% weight loss and maintenance groups, and compared. In addition, we examined factors affecting weight loss by age. The analysis method used was the χ2 test, and the t-test was used for comparison of the two groups. Factors associated with 5% weight loss at 3 years were examined using logistic regression analysis with sex, age, married couple, cognitive function, grip strength, and the serum albumin level as explanatory variables. RESULTS: Of the 1157 subjects, the proportions showing 5% weight loss after 3 years among all subjects, those aged 70 years, 80 years, and 90 years, were 20.5, 13.8, 26.8, and 30.5%, respectively. In logistic regression analysis, factors associated with 5% weight loss at 3 years by age were influenced by BMI of 25 or higher (OR = 1.90, 95%CI = 1.08-3.34, p = 0.026), a married couple (OR = 0.49, 95% = 0.28-0.86, p = 0.013), serum albumin level below 3.8 g/dL (OR = 10.75, 95% = 1.90-60.73, p = 0.007) at age 70, and the grip strength at age 90 (OR = 1.24, 95%CI = 1.02-1.51, p = 0.034), respectively. CONCLUSIONS: The results suggest that factors associated with weight loss by age in community-dwelling older people through a longitudinal study differ by age. In the future, this study will be useful to propose effective interventions to prevent factors associated with weight loss by age in community-dwelling older people.

The Relationship Between Social Interaction and Anxiety Regarding COVID-19 in Japanese Older Adults.

While previous studies suggest that women have higher anxiety than men regarding COVID-19, underlying mechanisms remain unclear. This study tries to explain the mechanisms by gender difference in social interaction based on a theory of social amplification of risk framework (SARF). We surveyed older adults in Japan regarding their anxiety regarding COVID-19, as well as the frequencies of their direct and indirect social interaction in July 2020 (N = 1,587, aged 78-99 years). To explore the way in which gender and anxiety regarding COVID-19 were mediated by these two types of social interactions, MODEL4 of SPSS's Process MACRO was applied to the data. We found that older women interacted more directly and indirectly with others than did older men. And, direct social interaction was negatively and related, but indirect social interaction was positively related to older adults' anxiety regarding COVID-19. Furthermore, direct social interaction was related to older women's low anxiety regarding COVID-19, whereas indirect social interaction was related to older women's high anxiety regarding COVID-19. The findings of our study suggest that the degree of anxiety regarding COVID-19 among older women may be dependent upon the types of social interaction they have with others.

[Relationship between glycemic control and mental health in community-dwelling older people with diabetes mellitus: The SONIC study].

AIM: The purpose of this study was to examine the relationship between glycemic control and mental health in community-dwelling older people with diabetes mellitus (DM) from insights that contribute to the management of diabetes in consideration of quality of life (QOL). METHODS: We used the data of the Septuagenarians, Octogenarians and Nonagenarians Investigation with Centenarians (SONIC) study, a prospective cohort study of community-dwelling older people. The present study included 2,051 older subjects of 70±1 years, 80±1 years and 90±1 years of age. We conducted medical interviews, blood sampling, and the subjects were asked to complete a questionnaire (WHO-5-J) at the venue. Three hundred sixty-eight people were diagnosed with DM. The subjects of this study were 192 people who were undergoing drug therapy for glycemic control. A multiple regression analysis was performed to clarify the relationship between glycemic control (divided as follows: HbA1c<7.0%, good control group; HbA1c≥7.0%, poor control group) and the WHO-5-J score, as the dependent variable, after adjusting for any confounding factors. RESULTS: In subjects of 70 years of age, a negative association was found between glycemic control and the WHO-5-J score, with the good control group showing a significantly lower score (ß: -0.468, p<0.01) in comparison to the poor control group. In detail, we observed a significant difference in the sub-items of WHO-5-J, question item 3, "I have felt active and vigorous" at 70 years of age (good control group, 2.56±1.37; poor control group, 3.21±1.18; p=0.021) and question item 5, "My daily life has been filled with things that interest me" (good control group, 2.44±1.21; poor control group, 3.11±1.11; p=0.009). As for the two questions, the WHO-5-J scores were lower in the good control group. These associations showed no statistical significance at 80 years of age or 90 years of age. CONCLUSION: The results obtained in this study indicated that strict glycemic control management of diabetes mellitus may lead to a lower mental QOL in younger elderly individuals (70 years of age). Therefore, it is important to pay attention to the mental burdens of the management of glycemic control in older people with DM.

Longitudinal association of hypertension and dyslipidemia with cognitive function in community-dwelling older adults: the SONIC study.

The associations among cognitive function, hypertension, and dyslipidemia in older adults are controversial. Therefore, we investigated the associations among cognitive decline, hypertension, dyslipidemia, and their combination in community-dwelling older people in their 70s, 80s, and 90s in the long-term observational Septuagenarians, Octogenarians, Nonagenarians, Investigation with Centenarians (SONIC) study. We administered the Montreal Cognitive Assessment Japanese version (MoCA-J) by trained geriatricians and psychologists, and conducted blood testing and blood pressure (BP) measuring by medical staff involving 1186 participants. We performed multiple regression analysis to assess the relationships among hypertension, dyslipidemia, their combination, and lipid and BP levels with cognitive function at the 3-year follow-up after adjusting for covariate factors. At the baseline, the percentage of the combination of hypertension and dyslipidemia was 46.6% (n = 553), hypertension was 25.6% (n = 304), dyslipidemia was 15.0% (n = 178), and that without hypertension or dyslipidemia was 12.7% (n = 151). Conducting multiple regression analysis, no significant correlation was found between the combination of hypertension and dyslipidemia and MoCA-J score. In the group with the combination, high high-density lipoprotein cholesterol (HDL) levels resulted in higher MoCA-J scores at the follow-up (ß = 0.06; P < 0.05) and high diastolic BP (DBP) also resulted in higher MoCA-J scores (ß = 0.08; P < 0.05). The results suggest that high HDL and DBP levels of individuals with HT & DL and high SBP levels of individuals with HT were associated with cognitive function in community-dwelling older adults. In the SONIC study, which is an epidemiological study of Japanese older persons aged 70 years or older, a disease-specific examination suggested that high HDL and DBP levels of individuals with hypertension & dyslipidemia and high SBP levels of individuals with hypertension were associated with maintaining cognitive function in community-dwelling older adults.

Criterion validity of the health assessment questionnaire for the national screening program for older adults in Japan: The SONIC study.

AIM: In our previous study, we proposed that the total score of the 12 frailty-related items in the health assessment questionnaire for the national screening program for older adults could be used as an indicator of frailty. We aim to examine the criterion validity of the 12 frailty-related items for frailty. METHODS: The data used in this study were from older Japanese individuals aged 78-81 years (n = 461) who participated in the in-venue (2019) and mailed questionnaire (2020) surveys of the Septuagenarians, Octogenarians, Nonagenarians Investigation with Centenarians study. A receiver operator characteristic (ROC) curve analysis was used to evaluate the criterion validity of the 12 frailty-related items for frailty defined based on the Japanese version of the Cardiovascular Health Study criteria. A multivariable logistic regression model was used to examine the independent association of the 12 frailty-related items with frailty. RESULTS: The area under the ROC curve of the scores of the 12 frailty-related items for frailty was 0.79 (95% confidence interval [CI] = 0.73-0.85, P < 0.001). The cut-off value for frailty was 3 and 4 points, and the sensitivity and specificity were 55.9% and 85.8%, respectively. The multivariable logistic regression model showed that four or more scores of the 12 frailty-related items were significantly associated with frailty (adjusted odds ratio = 7.75, 95% CI = 4.10-14.65, P < 0.001). CONCLUSIONS: The results of this study suggest that the 12 frailty-related items in the health assessment questionnaire for older adults may be useful for assessing frailty in community-dwelling older adults in a simplified manner. Geriatr Gerontol Int 2023; 23: 437-443.

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.

Lower cognitive function as a risk factor for anemia among older Japanese women from the longitudinal observation in the SONIC study.

AIM: The aging-related increase in the incidence of anemia potentially affects the mortality risk. Lower cognitive function is common among older adults, and anemia is one of the causes of cognitive decline. However, to the best of our knowledge, no study has investigated whether cognitive decline is a risk factor for anemia in older people. Therefore, in this study, we used a 3-year longitudinal evaluation to examine the association of cognitive function with anemia in community-dwelling older adults. METHODS: This longitudinal study enrolled participants without anemia (diagnosed based on the World Health Organization's criteria) at baseline. Cognitive function was assessed using the Japanese version of the Montreal Cognitive Assessment. Multiple logistic regression models were used to examine the association between cognitive function at baseline and the presence of anemia 3 years later. RESULTS: Participants were in the 69-71 and 79-81 years age groups, and 974 older people (48.6% men) were enrolled, of whom 126 (12.9%) had anemia after 3 years. After adjusting, cognitive function at baseline was associated with anemia in women, but not in men. CONCLUSIONS: Older Japanese women with lower cognitive function have an increased risk for anemia 3 years later. The adoption of a lifestyle that utilizes or improves cognitive function might be important to prevent anemia in older women. Geriatr Gerontol Int 2023; 23: 334-340.

Early- to late-life environmental factors and late-life global cognition in septuagenarian and octogenarians: The SONIC study.

This study aimed to evaluate cognitively stimulating environments throughout life and to examine direct and indirect associations between these environments and late-life cognition. Early-life education, three domains of work complexity (data, people, and things) based on the longest-held occupation, and engagement in late-life leisure activities (LAs) were assessed. A structural equation model was developed using cross-sectional data of 1721 Japanese older adults in 70 ± 1 and 80 ± 1 years. The model confirmed significant direct effects of work complexity with data and late-life LAs on late-life cognitive performance. The associations of education and work complexity with late-life cognition were mediated through the subsequent environment(s). However, the total effects of work complexity with people and things on late-life cognition were insignificant. The findings suggest that cognitively stimulating activities in adulthood and beyond may lead to individual differences in late-life global cognition. In addition, antecedent complex environments might make subsequent life environments more cognitively stimulating. The results are discussed from the perspectives of cognitive plasticity and environmental complexity.

Relationship between occlusal force and psychological frailty in Japanese community-dwelling older adults: The Septuagenarians, Octogenarians, Nonagenarians Investigation with Centenarians study.

BACKGROUND: Frailty increases the risk of negative health-related events, such as falls, disability, hospitalizations, and death. Although the association between oral health and physical frailty is well established, the relationship between oral health and psychological frailty has not yet been investigated. Therefore, we conducted a cross-sectional study to examine the association between maximal occlusal force and psychological frailty in Japanese community-dwelling older adults. METHODS: Psychological frailty was defined as a World Health Organization-5 scale (WHO-5) score of <13, cognitive and functional status was defined as a Japanese version of the Montreal Cognitive Assessment (MoCA-J) score of <23, and psychological robustness was defined as a WHO-5 score of ≥13 and a MoCA-J score of ≥23. We used a cross-sectional study design to measure maximal occlusal force in 1810 participants, and examined the following factors relevant to psychological frailty: educational level, financial status, living situation, history of chronic diseases, handgrip strength, and instrumental activities of daily living. We used propensity score matching to match the psychological frailty and psychological robustness groups according to demographic and confounding factors. This process, resulted in 344 participants, of whom 172 were in the psychological frailty group and 172 were in the psychological robustness group. In the matched cohort, differences between groups with and without psychological frailty were compared using generalized estimating equations for maximal occlusal force after adjusting for the number of teeth. RESULTS: After controlling for potential confounding factors of frailty, the psychological frailty group showed lower maximal occlusal force compared with the psychological robustness group (unstandardized regression coefficients = -72.7, 95% confidence interval: -126.3 to -19.1). CONCLUSIONS: Maximal occlusal force was associated with a reduced prevalence of psychological frailty among Japanese community-dwelling older adults participating in our study.

A characteristic N-glycopeptide signature associated with diabetic cognitive impairment identified in a longitudinal cohort study.

BACKGROUND: Identifying a biomarker for the decline in cognitive function in patients with diabetes is important. Therefore, we aimed to identify the N-glycopeptides on plasma proteins associated with diabetic cognitive impairment in participants in a longitudinal study using N-glycoproteomics. METHODS: We used samples from the 3-year SONIC (Septuagenarians, Octogenarians, Nonagenarians Investigation with Centenarians) longitudinal cohort study of older Japanese people in the general population. First, we placed the participants with diabetes into two groups: those that did or did not have cognitive decline over a 6-year period. Next, their plasma protein profiles were compared between baseline and the 6-year time point using two-dimensional fluorescence difference gel electrophoresis. Finally, an N-glycoproteomic study of the focused proteins was performed using an enrichment technique and liquid chromatography-tandem mass spectrometry. RESULTS: Approximately 500 N-glycopeptides, derived from 18 proteins, were identified in each sample, from among which we identified the N-glycopeptides that were associated with diabetic cognitive impairment using multivariate analysis. We found that N-glycopeptides with sialylated tri- or tetra-antennary glycans on alpha-2-macroglobulin, clusterin, serum paraoxonase/arylesterase 1, and haptoglobin were less abundant, whereas 3-sialylated tri-antennary N-glycopeptides on serotransferrin were more abundant. CONCLUSION: N-glycopeptides with sialylated multi-antennary glycans comprise a characteristic signature associated with diabetic cognitive impairment. GENERAL SIGNIFICANCE: The characterized N-glycopeptides represent potential biomarker candidates for diabetic cognitive impairment.