OBJECTIVE: To identify the interrelationships and discriminatory value of a broad range of objectively measured explanatory risk factors for falls.
DESIGN: Prospective cohort study with 12‐month ...follow‐up period.
SETTING: Community sample.
PARTICIPANTS: Five hundred community‐dwelling people aged 70 to 90.
MEASUREMENTS: All participants underwent assessments on medical, disability, physical, cognitive, and psychological measures. Fallers were defined as people who had at least one injurious fall or at least two noninjurious falls during a 12‐month follow‐up period.
RESULTS: Univariate regression analyses identified the following fall risk factors: disability, poor performance on physical tests, depressive symptoms, poor executive function, concern about falling, and previous falls. Classification and regression tree analysis revealed that balance‐related impairments were critical predictors of falls. In those with good balance, disability and exercise levels influenced future fall risk—people in the lowest and the highest exercise tertiles were at greater risk. In those with impaired balance, different risk factors predicted greater fall risk—poor executive function, poor dynamic balance, and low exercise levels. Absolute risks for falls ranged from 11% in those with no risk factors to 54% in the highest‐risk group.
CONCLUSIONS: A classification and regression tree approach highlighted interrelationships and discriminatory value of important explanatory fall risk factors. The information may prove useful in clinical settings to assist in tailoring interventions to maximize the potential benefit of falls prevention strategies.
Since Alzheimer disease (AD) is a slowly progressive disorder and its pathologic features are likely to be present for many years before symptoms become manifest, we investigated whether ...microstructural white matter changes similar to those identified in patients with AD can be detected in cognitively normal individuals without dementia destined to develop amnestic mild cognitive impairment (aMCI).
We studied 193 cognitively normal individuals, of whom 173 remained cognitively stable (CN-stable) and 20 were diagnosed with aMCI (CN-aMCI converter) 2 years later. Structural MRI and diffusion tensor imaging were acquired at baseline to assess gray matter atrophy and microstructural white matter changes, respectively.
At baseline, compared with CN-stable, CN-aMCI converters had substantial reductions in white matter integrity in the precuneus, parahippocampal cingulum, parahippocampal gyrus white matter, and fornix. Other diffuse white matter changes were observed in the frontal, parietal, and subcortical regions, whereas gray matter structures were relatively intact. The fractional anisotropy (FA) values of the precuneus were found to be a predictor of conversion from cognitively normal to aMCI. In addition, the FA values of the left parahippocampal gyrus white matter were predictive of subsequent episodic memory decline.
Microstructural white matter changes are present in cognitively normal individuals in the pre-aMCI stage, and may serve as a potential imaging marker of early AD-related brain changes.
Abstract
Objectives
This study assessed whether reciprocal relationships exist between cognitive function and the social network size of older adults, controlling for age, sex, education, medical ...conditions, and depressive symptoms.
Methods
Data were collected at biennial follow-ups over 6 years in the Sydney Memory and Ageing Study, a longitudinal cohort study including 1,037 community-based Sydney residents aged 70–90 years without dementia at baseline. We used random intercept cross-lagged panel models to investigate reciprocal associations between social network size and scores in each of 7 cognitive domains including a global score.
Results
Standardized models indicated that within-person deviation in expected language score predicted deviation in expected network size. Within-person deviation in prior expected social network size predicted deviation in expected executive function at year 6. Cross-lagged effects in models of both global cognition and memory, respectively, could not be attributed solely to within-person change.
Discussion
Findings support a co-constitutive view of cognitive function and social relationships in older age. Although both cognition and network size declined over time, slower than expected decline in language ability predicted less than expected contraction in social networks. A similar influence of network size on executive functioning indicated that relationships with friends and family outside of the home contributed significantly to the maintenance of higher order cognitive abilities in older late life. Diverse patterns of influence between cognitive domains and social network size over 6 years underscore the importance of assessing the complex and nuanced interplay between brain health and social relationships in older age.
An aging population brings increasing burdens and costs to individuals and society arising from late-life cognitive decline, the causes of which are unclear. We aimed to identify factors predicting ...late-life cognitive decline.
Participants were 889 community-dwelling 70-90-year-olds from the Sydney Memory and Ageing Study with comprehensive neuropsychological assessments at baseline and a 2-year follow-up and initially without dementia. Cognitive decline was considered as incident mild cognitive impairment (MCI) or dementia, as well as decreases in attention/processing speed, executive function, memory, and global cognition. Associations with baseline demographic, lifestyle, health and medical factors were determined.
All cognitive measures showed decline and 14% of participants developed incident MCI or dementia. Across all participants, risk factors for decline included older age and poorer smelling ability most prominently, but also more education, history of depression, being male, higher homocysteine, coronary artery disease, arthritis, low health status, and stroke. Protective factors included marriage, kidney disease, and antidepressant use. For some of these factors the association varied with age or differed between men and women. Additional risk and protective factors that were strictly age- and/or sex-dependent were also identified. We found salient population attributable risks (8.7-49.5%) for older age, being male or unmarried, poor smelling ability, coronary artery disease, arthritis, stroke, and high homocysteine.
Preventing or treating conditions typically associated with aging might reduce population-wide late-life cognitive decline. Interventions tailored to particular age and sex groups may offer further benefits.
To document the prevalence of self- and informant report of cognitive problems, usually referred to as "subjective cognitive complaints" (SCCs), in a community-dwelling sample of older adults and to ...examine the relationship between SCCs and objective impairment, mood, and personality measures.
Eight hundred twenty-seven nondemented community-dwelling adults aged 70-90 years.
Participants were asked 24 SCC questions, including the Memory Complaint Questionnaire (MAC-Q), and completed neuropsychological testing in the domains of memory, language, executive function, visuospatial skills, and psychomotor speed. The Geriatric Depression Scale, Goldberg Anxiety Scale, and Neuroticism, Openness, and Conscientiousness from the NEO-Five Factor Inventory were used as measures of participants' psychological status. Informants completed 19 SCC questions, including a modified short Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE).
Overall, 95.5% of participants or their informants endorsed at least one SCC. Although participants were more likely to endorse a memory complaint, informants seemed more accurate in endorsing a complaint when cognitive impairment was objectively present. SCC correlated with participants' scores on measures of depression, anxiety, neuroticism, and inversely with measures of openness and conscientiousness. Age, education, and sex had little impact on these effects. Regression analysis showed that psychological factors explained the number of complaints more than cognitive performance.
The usefulness of SCCs as a criterion for mild cognitive impairment is questioned because of their high prevalence and their relationship to psychological factors. This may be helpful for clinicians to bear in mind when presented with patients with cognitive complaints.
Intraindividual variability of reaction time (IIVRT), a proposed cognitive marker of neurobiological disturbance, increases in old age, and has been associated with dementia and mortality. The extent ...to which IIVRT is an independent predictor of mortality, however, is unclear. This study investigated the association of IIVRT and all-cause mortality while accounting for cognitive level, incident dementia and biomedical risk factors in 861 participants aged 70-90 from the Sydney Memory and Ageing Study. Participants completed two computerised reaction time (RT) tasks (76 trials in total) at baseline, and comprehensive medical and neuropsychological assessments every 2 years. Composite RT measures were derived from the two tasks-the mean RT and the IIVRT measure computed from the intraindividual standard deviation of the RTs (with age and time-on-task effects partialled out). Consensus dementia diagnoses were made by an expert panel of clinicians using clinical criteria, and mortality data were obtained from a state registry. Cox proportional hazards models estimated the association of IIVRT and mean RT with survival time over 8 years during which 191 (22.2%) participants died. Greater IIVRT but not mean RT significantly predicted survival time after adjusting for age, sex, global cognition score, cardiovascular risk index and apolipoprotein ɛ4 status. After excluding incident dementia cases, the association of IIVRT with mortality changed very little. Our findings suggest that greater IIVRT uniquely predicts shorter time to death and that lower global cognition and prodromal dementia in older individuals do not explain this relationship.
Background
The modified Telephone Interview for Cognitive Status (TICS‐M) is a widely used tool for assessing global cognitive functions and screening for cognitive impairments. The tool was ...conceptualised to capture various cognitive domains, but the validity of such domains has not been investigated against comprehensive neuropsychological assessments tools. Therefore, this study aimed to explore the associations between the TICS‐M domains and neuropsychological domains to evaluate the validity of the TICS‐M domains using network analysis.
Materials and Methods
A longitudinal research design was used with a large sample of older adults (aged above 70 years; n = 1037 at the baseline assessment) who completed the TICS‐M and comprehensive neuropsychological assessments biennially. We applied network analysis to identify unique links between the TICS‐M domains and neuropsychological test scores.
Results
At baseline, there were weak internal links between the TICS‐M domains. The TICS‐M memory and language domains were significantly related to their corresponding neuropsychological domains. The TICS‐M attention domain had significant associations with executive function and visuospatial abilities. The TICS‐M orientation domain was not significantly associated with any of the five neuropsychological domains. Despite an attrition of almost 50% at wave four, weak internal links between the TICS‐M domains and most associations between TICS‐M and neuropsychological domains that were found initially, remained stable at least over two waves within the 6‐year period.
Conclusions
This study supports the overall structural validity of the TICS‐M screener in assessing enduring global cognitive function. However, separate TICS‐M cognitive domains should not be considered equivalent to the analogous neuropsychological domains.
Validate domains of the modified telephone interview for cognitive status using network analysis.
Centenarians without dementia can be considered as a model of successful ageing and resistance against age-related cognitive decline. Is there something special about their brain functional ...connectivity that helps them preserve cognitive function into the 11th decade of life? In a cohort of 57 dementia-free near-centenarians and centenarians (95–103 years old) and 66 cognitively unimpaired younger participants (76–79 years old), we aimed to investigate brain functional characteristics in the extreme age range using resting-state functional MRI. Using group-level independent component analysis and dual regression, results showed group differences in the functional connectivity of seven group-level independent component (IC) templates, after accounting for sex, education years, and grey matter volume, and correcting for multiple testing at family-wise error rate of 0.05. After Bonferroni correction for testing 30 IC templates, near-centenarians and centenarians showed stronger functional connectivity between right frontoparietal control network (FPCN) and left inferior frontal gyrus (Bonferroni-corrected p = 0.024), a core region of the left FPCN. The investigation of between-IC functional connectivity confirmed the voxel-wise result by showing stronger functional connectivity between bilateral FPCNs in near-centenarians and centenarians compared to young-old controls. In addition, near-centenarians and centenarians had weaker functional connectivity between default mode network and fronto-temporo-parietal network compared to young-old controls. In near-centenarians and centenarians, stronger functional connectivity between bilateral FPCNs was associated with better cognitive performance in the visuospatial domain. The current study highlights the key role of bilateral FPCN connectivity in the reserve capacity against age-related cognitive decline.
•We studied functional connectivity (FC) in near-centenarians and centenarians (nCC).•NCC showed stronger FC between bilateral frontoparietal control network (FPCN).•The stronger bilateral FPCN FC was linked to better visuospatial ability in nCC.
Evidence suggests that lifestyle activities impact cognitive and mental health in older populations. However, how lifestyle factors are associated with one another, and which factors are most ...important for cognitive function and mental health has received comparatively little attention.
Bayesian-Gaussian network analysis was used to investigate unique associations between mental activities (MA; i.e., activities involving cognitive engagement), global cognition, and depression at three time-points in a large sample of older adults (baseline, 2 years, and 4 years follow-up).
This study used longitudinal data from participants living in Australia and participating in the Sydney Memory and Ageing Study.
The sample included 998 participants (55% female) aged between 70 and 90, without a diagnosis of dementia at baseline.
Neuropsychological assessment of global cognition, self-reported depressive symptoms, and self-reported information about daily MA.
Cognitive functioning was positively associated with playing tabletop games and using the internet in both sexes at all time-points. MA were differentially linked in men and women. Depression was not consistently associated with MA in men across the three time-points; women who visited artistic events consistently had lower depression scores.
Engaging with tabletop games and using the internet was associated with better cognition in both sexes, however sex acted as a modifier for other associations. These findings are useful for future investigations that consider interactive associations between MA, cognition, and mental health in older adults, and their possible roles in promoting healthy aging.
Abstract
Objectives
This study aimed to test whether prospective memory (PM) was an early cognitive marker of future cognitive decline and incident dementia using longitudinal data spanning 8 years ...from the Sydney Memory and Ageing Study.
Methods
At baseline, 121 participants aged 72–91 years were tested in PM using a validated PM task, Virtual Week, which included time- and event-based tasks presented with varying regularity. Responses were scored “Correct” if completed accurately and “Missed” if the target was not remembered at any time. Measures of cognition were taken at baseline and 2-year intervals over 8 years. Dementia diagnoses were made by expert consensus panels using Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria. Linear mixed models and Cox proportional hazards regression models were used to analyze the data, controlling for potential confounds.
Results
Both decreased PM accuracy and missed PM responses were associated with rate of cognitive decline measured by Mini-Mental State Examination over 8 years and global cognitive decline over 4 years. Risk of incident dementia increased with poorer baseline PM ability and missed responses. These effects remained significant after controlling for baseline cognition and were strongest for event-based and regular PM tasks.
Discussion
PM is a sensitive early marker of future cognitive decline and risk of incident dementia. PM tasks supported by spontaneous retrieval (event-based) and those with lower retrospective memory demands (regular tasks) function as particularly sensitive predictors. In other words, deficits in performing less effortful PM tasks best predicted cognitive decline. These findings may encourage clinicians to incorporate PM tasks in clinical assessments.
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