Mini-Mental State Examination score trajectories and incident disabling dementia among community-dwelling older Japanese adults

Sex differences in cognitive function trajectories and their determinants in older adults: Evidence from the Chinese longitudinal healthy longevity survey

OBJECTIVES

To examine sex differences in the cognitive trajectories of a nationally representative sample of older people living in China and to explore potential determinants of these trajectories.

METHODS

The study included 2230 women and 2171 men who were cognitively healthy and aged over 60 at the first observation from the Chinese Longitudinal Healthy Longevity Survey based on the 2008-2018 cohort. Cognitive function was measured using the Chinese version of the Mini-Mental State Examination (MMSE). Group-based trajectory modeling was used to identify potential heterogeneity of longitudinal changes over the 10 years in each gender. Logistic regression was used to investigate associations between baseline characteristics (age, education, fertility history, sleep length, physical activity, and health status and behaviors) and trajectory classes.

RESULTS

Three trajectories (labeled stable, slow decline, and rapid decline) were identified according to the changes in MMSE scores for both women and men. For the women, both the slow and rapid decline groups accounted for a larger proportion (14.7% and 11.0%, respectively) than the male decline groups (8.1% and 6.6%, respectively), and the women had a lower baseline MMSE score with a faster decline. In the multivariable logistic regression analyses, older age, less education, older age at first birth, poorer functional abilities, hearing impairment, and lower baseline MMSE scores were significantly associated with cognitive decline in both the female and male groups compared to the stable group. For the women, sleeping over 9 h was also associated with a rapid cognitive decline trajectory, while current exercise and being overweight/obese were protective factors against cognitive decline.

CONCLUSIONS

The women had an overall more serious cognitive decline than men. The potential determinants of cognitive decline identified in this study could be considered for developing specific intervention strategies aimed at promoting a healthy brain and preventing cognitive decline in different sexes, especially in low-income and developing countries.

Predicting the incidence of mild cognitive impairment with a computer-based cognitive assessment tool in community-dwelling older adults: The Otassha study

This study examined the ability of a computer-based cognitive assessment tool (CompBased-CAT) to predict mild cognitive impairment (MCI) in community-dwelling older adults. A two-year longitudinal study was conducted using data from 2016 to 2018 from the Otassha study cohort of community-dwelling older adults. MCI was defined as a Mini-Mental Status Examination (MMSE) score of <27. The CompBased-CAT was used at baseline, with each subtest score converted into a Z-score. Subsequently, the total Z-scores were calculated. Participants were divided into robust and MCI groups, and all variables were compared using the t-test or χ2 test. Receiver operating characteristic (ROC) curves and logistic regression analyses were conducted, with MCI and total Z-scores as dependent and independent variables, respectively. Among the 455 participants (median age, 72 years; range, 65-89 years; 282 women and 173 men), 32 developed MCI after two years. The participants in the MCI group were significantly older. They had lower maximal gait speed, baseline MMSE scores, subtest Z-scores, and total Z-scores than those in the robust group. The area under the ROC curve was 0.79 (95% confidence interval: 0.70-0.87; P <0.01). The sensitivity was 0.76, and the specificity was 0.75. The logistic regression analysis showed an odds ratio of 1.34 (95% confidence interval: 1.18-1.52; P <0.01). This study showed that CompBased-CAT can detect MCI, which is an early stage of dementia. Thus, CompBased-CAT can be used in future community health checkups and events for older adults.

Protective effects of dog ownership against the onset of disabling dementia in older community-dwelling Japanese: A longitudinal study

This prospective study examined the associations of dog/cat ownership with incident disabling dementia using propensity score matching based on the physical, social, and psychological characteristics of dog and cat owners. We also examined associations of the interaction between dog/cat ownership and exercise habit and social isolation with dementia. Overall, 11,194 older adults selected using stratified and random sampling strategies in 2016 were analyzed. Dog/cat ownership was defined as "current" or "past and never". Disabling dementia was defined according to physicians' rating in the long-term care insurance system in Japan during the approximately 4-year follow-up period. Statistical analysis was weighted by the inverse of the propensity score in the generalized estimating equation after adjusting for follow-up period. Current dog owners (8.6 %) had an odds ratio (OR) of 0.60 (95 %CI: 0.37-0.977) of having disabling dementia compared to past and never owners. For cat ownership, the corresponding OR was 0.98 (95 %CI: 0.62-1.55). Current dog owners with a regular exercise habit had an OR of 0.37 (0.20-0.68) compared to past and never dog owners with no exercise habit. Further, current dog owners with no social isolation had an OR of 0.41 (0.23-0.73) compared to past and never dog owners with social isolation. Dog ownership had a suppressive effect on incident disabling dementia after adjusting for background factors over a 4-year follow-up period. Specifically, dog owners with an exercise habit and no social isolation had a significantly lower risk of disabling dementia.

Association between Reduction of Muscle Mass and Faster Declines in Global Cognition among Older People: A 4-Year Prospective Cohort Study

OBJECTIVES

A few studies reported that both decrease and increase in body mass index (BMI) were associated with the development of dementia in later life. However, it is unclear what changes in body composition are associated with cognitive decline. This study investigated the longitudinal influences of changes in body composition on cognitive function among community-dwelling adults.

DESIGN, SETTING AND PARTICIPANTS

This longitudinal study included older adults aged ≥60 years without cognitive impairment who participated in National Institute for Longevity Sciences - Longitudinal Study of Aging.

MEASUREMENTS

Cognitive function was assessed using the MMSE. Body composition was measured by a dual-energy X-ray absorptiometry system. Then, BMI, fat mass index (FMI), fat-free mass index (FFMI), and muscle mass index (MMI) were calculated. The changes in body composition over 6 years (second wave to fifth wave) were calculated, and three groups were created: decreased group, decrease of >5%; stable group, change within 5%, and increased group, increase of >5%. In statistical analysis, a linear mixed model was applied by sex to investigate the influences of body composition changes on cognitive function over 4 years (fifth wave to seventh wave).

RESULTS

This study analyzed 515 participants (mean age, 67.05 years; 53.4% men). Men with decreased group in FFMI and MMI exhibited faster declines in MMSE scores than those with stable group (β [95% CI]: FFMI, -0.293 [-0.719 to -0.020]; MMI, -0.472 [-0.884 to -0.059]). In women, there was no significant association between body composition changes and cognitive functions.

CONCLUSIONS

Decrease in fat-free mass and muscle mass is associated with faster cognitive declines in men. These results suggest the importance of continuous monitoring of muscle mass to prevent cognitive decline in later life.

Activity diversity is associated with the prevention of frailty in community-dwelling older adults: The Otassha Study

Introduction

A prior study showed an association between diversity in daily activities (type, frequency, evenness) and frailty in older adults. However, the causality of this relationship is unclear. Therefore, this study aimed to clarify the relationship between activity diversity and frailty through a 2-year longitudinal study conducted among community-dwelling older adults.

Methods

We evaluated data from the 2018 and 2020 waves of the Otassha Study. Frailty was assessed using the Cardiovascular Health Study criteria, with pre-frail and frail participants defined as frail and the other participants categorized into the robust group. We enrolled a total of 207 participants who were not frail at baseline. Activity type, frequency, and evenness scores were calculated using an Activity Diversity Questionnaire. The association between each activity diversity score and the incidence of frailty was evaluated using logistic regression modeling (each diversity score was entered the model after Z-transformation).

Results

Of the 207 enrolled participants (median age, 73 years; age range, 65-91 years; 60.4% women), 64 (30.9%) had incident frailty during the follow-up period. A logistic regression analysis adjusting for sociodemographic and psychosomatic factors revealed odds ratios for activity type and evenness scores of 0.64 and 0.61, respectively (P < 0.05). These factors were significantly associated with the incidence of frailty.

Discussion

Activity type and evenness (except frequency) within daily activities were predictors of frailty during 2 years of follow-up. Engagement in diverse activities appears to be more effective in preventing frailty than does engagement in a few activities.

Predicting the long-term cognitive trajectories using machine learning approaches: A Chinese nationwide longitudinal database

OBJECTIVES

This study aimed to explore the long-term cognitive trajectories and its' determinants, and construct prediction models for identifying high-risk populations with unfavorable cognitive trajectories.

METHODS

This study included 3502 older adults aged 65-105 years at their first observations in a 16-year longitudinal cohort study. Cognitive function was measured by the Chinese version Mini Mental State Examination. The heterogeneity of cognitive function was identified through mixed growth model. Machine learning algorithms, namely regularized logistic regression (r-LR), support vector machine (SVM), random forest (RF), and super learner (SL) were used to predict cognitive trajectories. Discrimination and calibration metrics were used for performance evaluation.

RESULTS

Two distinct trajectories were identified according to the changes of MMSE scores: intact cognitive functioning (93.6%), and dementia (6.4%). Older age, female gender, Han ethnicity, having no schooling, rural residents, low-frequency leisure activities, and low baseline BADL score were associated with a rapid decline in cognitive function. r-LR, SVM, and SL performed well in predicting cognitive trajectories (Sensitivity: 0.73, G-mean: 0.65). Age and psychological well-being were key predictors.

CONCLUSION

Two cognitive trajectories were identified among older Chinese, and the identified key factors could be targeted for constructing early risk prediction models.

Resistance training improves cognitive function in older adults with different cognitive status: a systematic review and Meta-analysis

The present study investigated the impact of resistance training (RT) on cognitive function in older adults with different cognitive status by conducting a systematic review and meta-analysis of intervention studies. We performed a literature search with no restriction on publication year in MEDLINE, Embase, CINAHL, SPORTDiscus, and AgeLine from inception up to August 2020. Experimental studies investigating the impact of RT on the cognitive function of cognitively healthy (CH) and cognitively impaired (CI) older adults (≥60 years) were included for analysis. Eighteen studies were included in the final analysis, of which ten studies investigated CH community-dwelling older adult, seven studies investigated CI older adults, and one study investigated both. RT significantly improved overall cognitive function in both CH (SMD = 0.54; 95% CI = 0.00 to 1.08, P = 0.047) and CI (SMD = 0.60; 95% CI = 0.21 to 1.16, P = 0.005) older adults. However, short-term memory was only improved in CH older adults (MD = -0.20; 95% CI = -0.25 to -0.15, P < 0.00001). In conclusion, RT improved overall cognitive function in CH and CI older adults, whereas short-term memory, assessed by the digit span of the WAIS III, was only significantly improved in CH older adults.

Age-Related Cognitive Decline and Prevalence of Mild Cognitive Impairment in the Iwaki Health Promotion Project

BACKGROUND

The Iwaki Health Promotion Project (IHPP) is a community-based study for the prevention of lifestyle-related diseases and improvement of quality of life.

OBJECTIVE

Between 2014 and 2017, a total of 4,442 Iwaki town residents from 19 to 93 years of age participated in annual surveys to clarify the natural course of age-related cognitive decline and mild cognitive impairment (MCI).

METHODS

Modified OLD and SED-11Q questionnaires, MMSE, Logical Memory II, educational history, and APOE genotypes were examined at the first screening. MCI and dementia were diagnosed at the second examination by detailed neurological examination, CDR, and MRI, and followed for 3 years. Spline regression analyses based on a linear mixed model was adopted for statistical analysis.

RESULTS

MMSE scores declined with age from 55 to 64 years. There was also interaction between levels of education and ages. At the second examination, 56 MCI and 5 dementia patients were identified. None of the MCI cases progressed to dementia during the 3 years. During follow-up examinations, 13 cases showed improved MMSE scores (0.95 point/year), 5 remained stable, and 7 deteriorated (-0.83 point/year). Five cases showed improved CDR-SOB scores (-0.28 point/year), 9 remained stable, and 6 deteriorated (0.3 point/year).

CONCLUSION

IHPP revealed that age- and education-related cognitive decline began and advanced from 55 years of age. The prevalence of MCI and dementia was estimated to be 5.9%in the Iwaki town cohort over 60 yeas of age. About 30%of MCI cases showed progression of cognitive decline.

Differences in Trajectories and Predictive Factors of Cognition over Time in a Sample of Cognitively Healthy Adults, in Zaragoza, Spain

Great inter-individual variability has been reported in the maintenance of cognitive function in aging. We examined this heterogeneity by modeling cognitive trajectories in a population-based longitudinal study of adults aged 55+ years. We hypothesized that (1) distinct classes of cognitive trajectories would be found, and (2) between-class differences in associated factors would be observed. The sample comprised 2403 cognitively healthy individuals from the Zaragoza Dementia and Depression (ZARADEMP) project, who had at least three measurements of the Mini-Mental State Examination (MMSE) in a 12-year follow-up. Longitudinal changes in cognitive functioning were modeled using growth mixture models (GMM) in the data. The best-fitting age-adjusted model showed 3 distinct trajectories, with 1-high-to-moderate (21.2% of participants), 2-moderate-stable (67.5%) and, 3-low-and-declining (9.9%) cognitive function over time, respectively. Compared with the reference 2-trajectory, the association of education and depression was significantly different in trajectories 1 and 3. Instrumental activities of daily living (iADLs) were only associated with the declining trajectory. This suggests that intervention strategies should be tailored specifically to individuals with different trajectories of cognitive aging, and intervention strategies designed to maintain cognitive function might be different from those to prevent decline. A stable cognitive performance ('successful cognitive aging') rather than a mild decline, might be more 'normal' than generally expected.

Association between activity diversity and frailty among community-dwelling older Japanese: A cross-sectional study

PURPOSE

Deterioration of daily activities increases frailty risk. Most of the previous research has examined the association between frailty and specific activities; nevertheless, the diversity of daily activities is also important. Although the type, frequency, and evenness of daily activities have been proposed as indicators of activity diversity, the association between these indicators and frailty remains unclear. In this study, we examined the association between activity diversity and frailty in community-dwelling older adults.

MATERIALS AND METHODS

This cross-sectional study comprised 658 community-dwelling older adults aged ≥ 65 years who participated in comprehensive health check-ups in 2018. Frailty was defined using the Japanese version of the Cardiovascular Health Study criteria. Three indicators, type, frequency, and evenness of daily activities, were used to assess activity diversity across one week. Multiple logistic regression analyses were performed, with frailty as the dependent variable and the three activity diversity indicators as independent variables. Socio-demographic, physical, and mental functioning factors were adjusted as covariates.

RESULTS

Of the 658 participants (median age: 72 years; age range: 65-91 years; 60.5% women), 27 (4.1%) met the criteria for frailty. The frail group had significantly lower scores for type, frequency, and evenness of daily activities, as well as Mini-Mental State Examination scores (all at p < 0.01). We found significant independent associations in all activity diversity indicators with frailty, in multiple logistic models.

CONCLUSION

Activity diversity is independently associated with frailty in community-dwelling older adults.

Trajectories of cognitive function and their determinants in older people: 12 years of follow-up in the Chinese Longitudinal Healthy Longevity Survey

BACKGROUND

Cognitive decline in advanced age is closely related to dementia. The trajectory of cognitive function in older Chinese is yet to be fully investigated. We aimed to investigate the trajectories of cognitive function in a nationally representative sample of older people living in China and to explore the potential determinants of these trajectories.

METHODS

This study included 2,038 cognitively healthy persons aged 65-104 years at their first observation in the Chinese Longitudinal Healthy Longevity Survey from 2002 to 2014. Cognitive function was measured using the Chinese version of the Mini-Mental State Examination (MMSE). Group-based trajectory modeling was used to identify potential heterogeneity of longitudinal changes over the 12 years and to investigate associations between baseline predictors of group membership and these trajectories.

RESULTS

Three trajectories were identified according to the following types of changes in MMSE scores: slow decline (14.0%), rapid decline (4.5%), and stable function (81.5%). Older age, female gender, having no schooling, a low frequency of leisure activity, and a low baseline MMSE score were associated with the slow decline trajectory. Older age, body mass index (BMI) less than 18.5 kg/m2, and having more than one cardiovascular disease (CVD) were associated with the rapid decline trajectory.

CONCLUSION

Three trajectories of cognitive function were identified in the older Chinese population. The identified determinants of these trajectories could be targeted for developing prevention and intervention strategies for dementia.

Effects of Combined Resistance and Power Training on Cognitive Function in Older Women: A Randomized Controlled Trial

The present study compared the effects of traditional resistance training (TRT) and combined power training (PT) and TRT (PTRT) on cognitive parameters and serum brain-derived neurotrophic factor (BDNF) levels in non-demented, well-functioning, community-dwelling older women. Forty-five older women were randomized into one of three experimental groups: TRT, PTRT, and control group (CG). Cognitive tests explored global cognitive function, short-term memory, and dual-task performance. Serum BDNF levels were assessed at baseline and after the intervention. Exercise sessions were performed twice a week over 22 weeks. In TRT, exercise sessions were based on three sets of 8-10 repetitions at "difficult" intensity. In PTRT, the first session was based on PT (three sets of 8-10 repetitions at "moderate" intensity), while the second session was similar to the TRT. Our analyses indicated that overall cognitive function, short-term memory, and dual-task performance were similarly improved after TRT and PTRT. Serum BDNF concentrations were not altered by any training protocol. In conclusion, the two RT programs tested in the present trial improved global cognitive function, short-term memory and dual task performance in non-demented, well-functioning, community-dwelling older women. In addition, our findings suggest that mechanisms other than BDNF may be associated with such improvements.

Development and validity of the Computer-Based Cognitive Assessment Tool for intervention in community-dwelling older individuals

Aim

The Mini‐Mental State Examination is a widely used cognitive assessment tool. However, it has several limitations, including the learning effect and interrater reliability. Therefore, we developed a Computer‐Based Cognitive Assessment Tool (CompBased‐CAT), which runs on a tablet or personal computer. In this study, we examined the validity and discrimination ability of the CompBased‐CAT.

Methods

Participants were recruited from the Otasha‐Kenshin study carried out in 2016. We included 773 community‐dwelling older individuals in Japan (332 men, 441 women, aged 65–97 years). CompBased‐CAT scores were converted to z‐scores, and the correlation with Mini‐Mental State Examination scores was examined using Pearson's correlation coefficient. Furthermore, the ability to discern cognitive impairment was examined using the receiver operating characteristic curve.

Results

The Pearson's correlation coefficient for the Mini‐Mental State Examination scores and each task component of the CompBased‐CAT ranged from 0.24 to 0.41 (P < 0.001), and the correlation coefficient of the total z‐scores was 0.51 (P < 0.001). The sensitivity, specificity and area under the receiver operating characteristic curve of the discriminating ability of the CompBased‐CATool for cognitive impairment were 0.81, 0.77 and 0.85, respectively.

Conclusions

The CompBased‐CAT certainly possesses validity, discriminating ability and utility as a new cognitive assessment tool in community‐dwelling older individuals. Geriatr Gerontol Int 2020; ••: ••–••.

Association of trajectories of cognitive function with cause-specific mortality and medical and long-term care costs

AIM

Cognitive decline increases mortality risk through dementia-related pathways and might be associated with increased healthcare costs. Using up to 12 years of repeated measures data, we identified trajectories in cognitive function among community-dwelling older Japanese adults. We then examined whether these trajectories were associated with all-cause and cause-specific mortality, and differences in healthcare costs.

METHODS

A total of 1736 adults aged ≥65 years who were free of disabling dementia completed annual assessments during 2002-2014. Cognitive function was assessed with the Mini-Mental State Examination. The average number of follow-up assessments was 3.9, and the total number of observations was 6824 during the follow-up period.

RESULTS

We identified five trajectory patterns in cognitive function (high, second, third, fourth, and low) during the 12-year follow-up period. The low (2.0%) and fourth (2.2%) trajectory groups had higher hazard ratios for cardiovascular disease mortality, and hazard ratios for other cause mortality were significantly higher for the third (16.8%) and second (38.8%) trajectory groups than for the high trajectory group (40.3%). Until 5 years of follow up, participants in the two lower-trajectory groups had higher mean combined monthly medical and long-term care costs. After 8 years of follow up, mean costs were highest for the third trajectory.

CONCLUSIONS

The risk of death from cardiovascular disease was higher in the two lower-trajectory groups in cognitive function, and they showed higher healthcare costs during the first 5 years of follow up. After 8 years of follow up, the third trajectory had the highest healthcare costs, perhaps because of hospitalizations attributable to gradual cognitive decline. Geriatr Gerontol Int 2019; 19: 1236-1242.