The relative temporal sequence of decline in mobility and cognition among initially unimpaired older adults: Results from the Baltimore Longitudinal Study of Aging

A new nomogram model for the individualized prediction of mild cognitive impairment in elderly patients with type 2 diabetes mellitus

Background

A high risk of developing mild cognitive impairment (MCI) is faced by elderly patients with type 2 diabetes mellitus (T2DM). In this study, independent risk factors for MCI in elderly patients with T2DM were investigated, and an individualized nomogram model was developed.

Methods

In this study, clinical data of elderly patients with T2DM admitted to the endocrine ward of the hospital from November 2021 to March 2023 were collected to evaluate cognitive function using the Montreal Cognitive Assessment scale. To screen the independent risk factors for MCI in elderly patients with T2DM, a logistic multifactorial regression model was employed. In addition, a nomogram to detect MCI was developed based on the findings of logistic multifactorial regression analysis. Furthermore, the accuracy of the prediction model was evaluated using calibration and receiver operating characteristic curves. Finally, decision curve analysis was used to evaluate the clinical utility of the nomogram.

Results

In this study, 306 patients were included. Among them, 186 patients were identified as having MCI. The results of multivariate logistic regression analysis demonstrated that educational level, duration of diabetes, depression, glycated hemoglobin, walking speed, and sedentary duration were independently correlated with MCI, and correlation analyses showed which influencing factors were significantly correlated with cognitive function (p <0.05). The nomogram based on these factors had an area under the curve of 0.893 (95%CI:0.856-0.930)(p <0.05), and the sensitivity and specificity were 0.785 and 0.850, respectively. An adequate fit of the nomogram in the predictive value was demonstrated by the calibration plot.

Conclusions

The nomogram developed in this study exhibits high accuracy in predicting the occurrence of cognitive dysfunction in elderly patients with T2DM, thereby offering a clinical basis for detecting MCI in patients with T2DM.

Implications of metabolism on multi-systems healthy aging across the lifespan

Aging is increasingly thought to involve dysregulation of metabolism in multiple organ systems that culminate in decreased functional capacity and morbidity. Here, we seek to understand complex interactions among metabolism, aging, and systems-wide phenotypes across the lifespan. Among 2469 adults (mean age 74.7 years; 38% Black) in the Health, Aging and Body Composition study we identified metabolic cross-sectionally correlates across 20 multi-dimensional aging-related phenotypes spanning seven domains. We used LASSO-PCA and bioinformatic techniques to summarize metabolome-phenome relationships and derive metabolic scores, which were subsequently linked to healthy aging, mortality, and incident outcomes (cardiovascular disease, disability, dementia, and cancer) over 9 years. To clarify the relationship of metabolism in early adulthood to aging, we tested association of these metabolic scores with aging phenotypes/outcomes in 2320 participants (mean age 32.1, 44% Black) of the Coronary Artery Risk Development in Young Adults (CARDIA) study. We observed significant overlap in metabolic correlates across the seven aging domains, specifying pathways of mitochondrial/cellular energetics, host-commensal metabolism, inflammation, and oxidative stress. Across four metabolic scores (body composition, mental-physical performance, muscle strength, and physical activity), we found strong associations with healthy aging and incident outcomes, robust to adjustment for risk factors. Metabolic scores for participants four decades younger in CARDIA were related to incident cardiovascular, metabolic, and neurocognitive performance, as well as long-term cardiovascular disease and mortality over three decades. Conserved metabolic states are strongly related to domain-specific aging and outcomes over the life-course relevant to energetics, host-commensal interactions, and mechanisms of innate immunity.

Dual cognitive and mobility impairments and future dementia - Setting a research agenda

Dual cognitive and mobility impairments are associated with an increased risk of dementia. Recent studies examining temporal trajectories of mobility and cognitive function in aging found that dual decline is associated with higher dementia risk than memory decline or gait decline only. Although initial data show that individuals with dual decline or impairment have excessive cardiovascular and metabolic risk factors, the causes of dual decline or what underlies dual decline with a high risk of dementia remain largely unknown. In December 2021, the National Institute on Aging Intramural and Extramural Programs jointly organized a workshop on Biology Underlying Moving and Thinking to explore the hypothesis that older persons with dual decline may develop dementia through a specific pathophysiological pathway. The working group discussed assessment methods for dual decline and possible mechanisms connecting dual decline with dementia risk and pinpointed the most critical questions to be addressed from a translational perspective.

The Bidirectional Association Between Cognitive Function and Gait Speed in Chinese Older Adults: Longitudinal Observational Study

BACKGROUND

Cognitive and gait speed decline are common conditions in older adults and are often associated with future adverse consequences. Although an association between cognitive function and gait speed has been demonstrated, its temporal sequence remains unclear, especially in older Chinese adults. Clarifying this could help identify interventions to improve public health in older adults.

OBJECTIVE

This study aims to examine the longitudinal reciprocal association between gait speed and cognitive function and the possible temporal sequence of changes in both factors in a national longitudinal cohort.

METHODS

Data were derived from 2 waves (2011 baseline and 2015 follow-up) of the China Health and Retirement Longitudinal Study (CHARLS). Participants 60 years or older, without dementia or Parkinson disease at baseline, and with completed data on gait speed and cognition at both baseline and follow-up were included. Usual gait speed was measured over two 2.5-m walks. Mental intactness and episodic memory were used to assess global cognitive function. Cross-lagged panel models and linear mixed-effects models were used to examine the association between cognition and gait speed over time. Standardized coefficients were reported.

RESULTS

A total of 3009 participants (mean age 66.4 years, SD 5.4 years; 1422/3009, 47.26%, female participants) were eligible for inclusion in our analyses. Cross-lagged panel analyses revealed that after accounting for baseline gait speed, cognition, and potential confounders, baseline global cognition (β=.117, 95% CI 0.082-0.152; P<.001), mental intactness (β=.082, 95% CI 0.047-0.118; P<.001), and episodic memory (β=.102, 95% CI 0.067-0.137; P<.001) were associated with subsequent gait speed. Simultaneously, baseline gait speed was also associated with subsequent global cognition (β=.056, 95% CI 0.024-0.087; P=.001), mental intactness (β=.039, 95% CI 0.008-0.069; P=.01), and episodic memory (β=.057, 95% CI 0.023-0.092; P=.001). The comparison of standardized cross-lagged coefficients suggested that the effect size of baseline global cognition on subsequent gait speed was significantly larger than the reverse effect (χ₁²=6.50, P for difference=.01). However, the effects of both mental intactness and episodic memory on subsequent gait speed were not significantly stronger than those of the reverse pathway (χ₁²=3.33, P for difference=.07 and χ₁²=3.21, P for difference=.07). Linear mixed-effects analyses further supported these bidirectional relationships, revealing that lower baseline cognitive scores predicted steeper declines in gait speed trajectory, and slower baseline gait speed predicted more declines in cognitive trajectory over time.

CONCLUSIONS

There is a longitudinal bidirectional association between usual gait speed and both global cognitive function and specific domains of mental intactness and episodic memory among Chinese older adults. Baseline global cognition is likely to have a stronger association with subsequent gait speed than the reverse pathway. This interlinkage is noteworthy and may have implications for public health. Maintaining normal cognitive function may be an important interventional strategy for mitigating age-related gait speed reduction.

Balance performance and grip strength as predictors of cognitive function among community-dwelling older adults in the USA

Objectives

To investigate how balance and grip strength predicts the probability of cognitive function impairment (i.e., executive function: mild and mild-to-moderate impairment, and delayed recall) over eight years in community-dwelling older adults in the US, controlling for sex and race/ethnicity.

Methods

The National Health and Aging Trends Study dataset (2011 - 2018) was employed. Dependent variables included the Clock Drawing Test (Executive Function) and Delayed Word Recall Test. Longitudinal ordered logistic regression examined the association between cognitive function and predictors (i.e., balance and grip strength) over eight waves (n=9800, 1,225 per wave).

Results

Those who could complete side-by-side standing and semi-tandem tasks were 33% and 38% less likely to have mild or mild-to-moderate executive function impairment, respectively, relative to those who could not complete these tests. One score decrease in grip strength increased the executive function impairment risk by 13% (Odds Ratio: 0.87, CI: 0.79-0.95). Those who completed the side-by-side tasks were 35% (Odds Ratio: 0.65, CI: 0.44-0.95) less likely to experience delayed recall impairments than those who could not complete this test. With one score decrease in grip strength, the risk of delayed recall impairment was increased by 11% (OR: 0.89, CI: 0.80-1.00).

Conclusions

A combination of these two simple tests (i.e., semi-tandem stance and grip strength) can screen for cognitive impairment among community-dwelling older adults to identify people with mild and mild-to-moderate cognitive impairment in clinical settings.

Sensorimotor and Frontoparietal Network Connectivity Are Associated With Subsequent Maintenance of Gait Speed and Episodic Memory in Older Adults

BACKGROUND

Slow gait is predictive of functional impairments in older adults, while concomitant slow gait and cognitive complaints are associated with a greater risk for cognitive decline and dementia. However, functional neural correlates for gait speed maintenance are unclear. As the sensorimotor network (SMN) and frontoparietal network (FPN) are integral components of these functions, this study investigated differences in SMN and FPN in older adults with/without gait speed decline over 24 months; and whether these networks were associated with the maintenance of cognitive function.

METHODS

We included 42 community-dwelling older adults aged >70 years from the MOBILIZE Boston Study. Resting-state fMRI was performed at the study baseline. Participant characteristics, gait speed, Mini-Mental State Examination, and Hopkins Verbal Learning Test (HVLT) were assessed at baseline and at 24-month follow-up. Decliners were identified as individuals with >0.05 meters/second decline in gait speed from baseline to 24 months. Of the 26 decliners and 16 maintainers, decliners exhibited a significant decline in delayed-recall performance on the HVLT over 24 months.

RESULTS

Controlling for baseline age and multiple comparisons, contrary to initial hypothesis, maintainers exhibited lower baseline primary motor and premotor connectivity (p = .01) within the SMN, and greater baseline ventral visual-supramarginal gyrus connectivity within the FPN (p = .02) compared to decliners. Lower primary motor-premotor connectivity was correlated with maintenance of delayed-recall performance on the HVLT (p = .04).

CONCLUSION

These findings demonstrated a potential compensatory mechanism involved in the link between the decline in gait speed and episodic memory, whereby baseline connectivity of the SMN and FPN may underlie subsequent maintenance of gait speed and cognitive function in old age.

An innovative rehabilitation program for the veterans affairs post-acute skilled nursing setting: Preliminary results

BACKGROUND

Skilled nursing rehabilitative care plays a critical role in older adults' functional recovery impacting post-discharge outcomes. Variations across post-acute rehabilitative care services and patient outcomes indicate a need to improve rehabilitative care in this setting. We adapted a successful outpatient care program (Live Long Walk Strong-LLWS) to address this need in post-acute care settings within the Veterans Health Administration. LLWS differs from standard PT care by treating impairments linked to functional decline that are not traditionally targeted by standard care, providing formalized coaching to optimize behavior change, and providing post-discharge case management to optimize long-term outcomes. The purpose was to adapt, refine and implement the LLWS program for the Community Living Center (CLC), determine its acceptability and feasibility, and evaluate its preliminary effectiveness among older adults.

METHODS

The design of the program was adapted from the original outpatient LLWS program to the CLC setting through quality improvement methods and the Replicating Effective Programs (REP) framework. Primary outcomes included measures of feasibility and acceptability of >80% enrollment and completion of sessions as well as preliminary effectiveness using performance-based and patient-reported measures of function including the Short Physical Performance Battery (SPPB), AM-PAC, a Global Rating of Change questionnaire, and a satisfaction survey.

RESULTS

After 18 months, 51 Veterans had enrolled in the LLWS program, with 94.1% maintaining enrollment. We observed >80% completion of the inpatient and home follow-up sessions. Most patients were highly satisfied with care. Improvements in the SPPB (2.3 (SD 2.2) points), gait speed (0.17 (0.14) m/s) and the AM-PAC (6.5 (SD 5.7)) surpassed clinically meaningful thresholds.

CONCLUSIONS

This novel care program is feasible and acceptable to Veterans, demonstrating preliminary effectiveness with improving functional outcomes. Future research is needed to further examine the program's impact on other important outcomes relative to standard modes of care.

Cardiorespiratory Fitness Moderates the Age-Related Association Between Executive Functioning and Mobility: Evidence From Remote Assessments

Background and Objectives

In older adults, executive functions are important for daily-life function and mobility. Evidence suggests that the relationship between cognition and mobility is dynamic and could vary according to individual factors, but whether cardiorespiratory fitness reduces the age-related increase of interdependence between mobility and cognition remains unexplored.

Research Design and Methods

One hundred eighty-nine participants (aged 50-87) were divided into 3 groups according to their age: middle-aged (MA; <65), young older adults (YOA; 65-74), and old older adults (OOA; ≥75). Participants performed Timed Up and Go and executive functioning assessments (Oral Trail Making Test and Phonologic verbal fluency) remotely by videoconference. Participants completed the Matthews questionnaire to estimate their cardiorespiratory fitness (VO2 max in ml/min/kg). A 3-way moderation was used to address whether cardiorespiratory fitness interacts with age to moderate the relationship between cognition and mobility.

Results

Results showed that the cardiorespiratory fitness × age interaction moderated the association between executive functioning and mobility (β = -0.05; p = .048; R2 = 17.6; p < .001). At lower levels of physical fitness (<19.16 ml/min/kg), executive functioning significantly influenced YOA's mobility (β = -0.48, p = .004) and to a greater extent OOA's mobility (β = -0.96, p = .002).

Discussion and Implications

Our results support the idea of a dynamic relationship between mobility and executive functioning during aging and suggest that physical fitness could play a significant role in reducing their interdependency.

Do the dual-task "8-foot up and go" tests provide additional predictive value for early detection of cognitive decline in community-dwelling older women?

BACKGROUND

The 8-Foot Up and Go (8UG) test is a widely used mobility assessment. Some dual-task mobility assessments have been developed to help detect cognitive decline.

AIMS

This study developed a dual-task version of 8UG test to investigate the dual-task 8UG performance and to evaluate the ability of dual-task 8UG test in detecting cognitive decline.

METHODS

A total of 101 eligible community-dwelling women aged 60-74 years were grouped into the mild cognitive impairment group (MCI, n = 49) and the non-cognitive impairment group (NCI, n = 52). The 8UG tests under single-task (ST), manual dual-task (MT), and cognitive dual-task (CT) conditions were performed respectively. The dual-task cost (DTC) and the correct response rate (CRR) were calculated to quantify the dual-task interference.

RESULTS

Participants spent more time in performing the 8UG test under dual-task conditions. No differences were observed between NCI and MCI groups for 8UG parameters under ST and MT conditions (p > 0.05). When executing CT, significant differences were found in the number of correct answers and CRR (p < 0.05). CRR showed the strongest ability to predict MCI with a cut-off point of 0.50 (71.2% sensitivity and 61.2% specificity).

DISCUSSION

Both manual and cognitive dual-task were found to interfere with the 8UG performance. CRR with cutoff point of 0.50 could be a potential predictor of MCI in community-dwelling older women.

CONCLUSIONS

The CRR of the cognitive dual-task 8UG test could be recommended as a potential predictor for the early detection of MCI in community-dwelling older women.

The Role of Cognitive Performance and Physical Functions in the Association between Age and Gait Speed: A Mediation Study

Simple Summary

Age and mobility are interrelated. In this context, cognitive performance (CP) and physical functions (PF) play a mediating role. However, these concepts are multifaceted, and their interrelationships need further investigations. Thus, our study aims (1) to investigate the association between CP and PF with GS and (2) to examine whether CP and PF mediate the association between age and GS in a large sample of older Brazilian adults. The findings show that low levels of CP and PF were associated with a greater chance of the older individual presenting a slow GS. Moreover, the mediation model indicated that CP and PF mediated, by approximately 12% and 98%, respectively, the association between age and GS.

Abstract

Introduction: With vulnerable aging, gait speed (GS) undergoes progressive changes, becoming slower. In this process, cognitive performance (CP) and physical function (PF) both play an important role. This study aims (1) to investigate the association between CP and PF with GS and (2) to examine whether CP and PF mediate the association between age and GS in a large sample of Brazilian older adults. Methods: A cross-sectional study analyzed 697 individuals (mean age 70.35 ± 6.86 years) from the state of Amazonas. The CP was evaluated by the COGTEL test battery, PF by the Senior Fitness Test battery, and GS with the 50-foot Walk Test. Results: Older adults with a lower CP and PF had a 70% and 86% chance of slow GS, respectively. When CP and PF were placed simultaneously as mediators, the direct effect estimated by the model revealed a non-significant relationship between age and GS. Specifically, CP and PF mediated the association between age and GS, at approximately 12% and 98%, respectively. Conclusions: CP and PF show the potential to estimate GS performance among older adults. Moreover, CP and PF indicated a negative and direct association between age and slow GS, especially PF.

Gait Speed as a Biomarker of Cognitive Vulnerability: A Population-Based Study with Cognitively Normal Older Adults

We aimed to examine associations between cognitive vulnerability and gait speed (GS) in a large older sample. A cross-sectional study analyzed data from the “Health, Lifestyle and Fitness in Adults and Seniors in Amazonas” (SEVAAI) project. In total, 697 participants were included (mean age 70.35 ± 6.86 years). Usual and fast GS were evaluated, and cognitive performance was examined by the COGTEL test battery. There was a positive and large correlation between cognition (COGTEL score) and usual GS (r = 0.510; p < 0.001) and fast GS (r = 0.503; p < 0.001). The usual GS, as a continuous variable, indicated a chance of improved cognitive performance by up to 55%, and fast GS by up to 82%. After controlling for potential confounders (i.e., sex, age, MMSE and years of education), usual and fast GS indicated a chance of improving cognition, respectively, in 57% and 85%. Analysis of GS in quartiles (Q) showed high and significant associations between usual and fast GS and cognitive vulnerability. GS classified as Q1 (slower), Q2 and Q3 represented a greater chance of presenting cognitive deficits, respectively, than in participants with both GS classified as Q4 (highest). Cognitive vulnerability was associated with low GS. Usual and fast GS can be used as complementary measures for the evaluation of cognitively normal Brazilian older adults.

Association among cognitive function, physical fitness, and health status in older women

This study examined the association among cognitive function, physical fitness, and health status in healthy older women. Ninety-four females aged from 62 to 86 years (72.66±5.38 years) from community healthcare centers and an exercise club in Seoul, South Korea. Cognitive function was assessed using the Seoul Neuropsychological Screening Battery. Physical performance comprised cardiorespiratory endurance, lower extremity strength, active balance ability, and walking speed. Health status included blood pressure and waist circumference. Multiple linear regression analyses were performed to determine the relationship among cognitive function, fitness components, and health status, with age and educational attainment as covariates. In the unadjusted model, attention was significantly associated with cardiovascular endurance (B=0.19, P<0.05). Memory was significantly associated with lower limb strength (B=0.77, P<0.05) and active balance ability (B=2.35, P<0.05). In the adjusted model, attention was significantly associated with cardiovascular endurance (B=0.15, P<0.05). Memory was significantly associated with lower limb strength (B=0.87, P<0.05). In both models, cognitive function was not significantly associated with any health status variable. Though limited by a relatively small sample of female participants, who were healthy registrants of a community exercise program with normal cognitive function, the current study demonstrates that cognitive function is significantly associated with physical fitness, but not with health status, in healthy older women.

Association of walking energetics with amyloid beta status: Findings from the Baltimore Longitudinal Study of Aging

INTRODUCTION

Higher energetic costs for mobility predict gait speed decline. Slow gait is linked to cognitive decline and Alzheimer's disease (AD). Whether the energetic cost of walking is linked to AD pathology is unknown. We investigated the cross-sectional association between the energetic cost of walking, gait speed, and amyloid beta (Aβ) status (+/-) in older adults.

METHODS

One hundred forty-nine cognitively normal adults (56% women, mean age 77.5 ± 8.4 years) completed customary-paced walking assessments with indirect calorimetry and 11C-Pittsburgh compound B positron emission tomography. Logistic regression models examined associations adjusted for demographics, body composition, comorbid conditions, and apolipoprotein E ε4.

RESULTS

Each 0.01 mL/kg/m greater energy cost was associated with 18% higher odds of being Aβ+ (odds ratio [OR] = 1.18; 95% confidence interval [CI]: 1.04 to 1.34; P = .011). These findings were not observed when investigating gait speed (OR = 0.99; 95% CI: 0.97 to 1.01; P = .321).

DISCUSSION

High energetic cost of walking is linked to AD pathology and may be a potential target for therapeutic intervention.

Association of Vision Impairment With Cognitive Decline Across Multiple Domains in Older Adults

IMPORTANCE

Associations between visual and global cognitive impairments have been previously documented, but there is limited research examining these associations between multiple measures of vision across cognitive domains.

OBJECTIVE

To examine the association between vision and cognitive across multiple cognitive domains using multiple measures of vision.

DESIGN, SETTING, AND PARTICIPANTS

This longitudinal cohort study used data from the Baltimore Longitudinal Study of Aging for 2003 to 2019. Participants in the current study were aged 60 to 94 years with vision and cognitive measures. Data analysis was performed from May 2020 to May 2021.

MAIN OUTCOMES AND MEASURES

Cognitive function was measured across multiple domains, including language, memory, attention, executive function, and visuospatial ability. Cognitive domain scores were calculated as the mean of standardized cognitive test scores within each domain. Visual function was assessed using measures of visual acuity, contrast sensitivity, and stereo acuity at baseline.

RESULTS

Analyses included 1202 participants (610 women [50.8%]; 853 White participants [71.0%]) with a mean (SD) age of 71.1 (8.6) years who were followed up for a mean (SD) of 6.9 (4.7) years. Worse visual acuity (per 0.1 logarithm of the minimal angle of resolution) at baseline was associated with greater declines in language (β, -0.0035; 95% CI, -0.007 to -0.001) and memory (β, -0.0052; 95% CI, -0.010 to -0.001) domain scores. Worse contrast sensitivity (per 0.1 log units) at baseline was associated with greater declines in language (β, -0.010; 95% CI, -0.014 to -0.006), memory (β, -0.009; 95% CI, -0.015 to -0.003), attention (β, -0.010; 95% CI, -0.017 to -0.003), and visuospatial ability (β, -0.010; 95% CI, -0.017 to -0.002) domain scores. Over the follow-up period, declines on tests of language (β, -0.019; 95% CI, -0.034 to -0.005) and memory (β, -0.032; 95% CI, -0.051 to -0.012) were significantly greater for participants with impaired stereo acuity compared with those without such impairment.

CONCLUSIONS AND RELEVANCE

These findings suggest that the association between vision and cognition differs between visual acuity, contrast sensitivity, and stereo acuity and that patterns of cognitive decline may differ by type of vision impairment, with impaired contrast sensitivity being associated with declines across more cognitive domains than other measures of visual functioning.

Mobility impact and well-being in later life: A multidisciplinary systematic review

In modern societies, the understanding of how active mobility affects the elderly's psycho-physical well-being is crucial to design ageing-friendly transport measures. From a multidisciplinary perspective, this systematic review points out the mobility impact on three elements of the EU Active Ageing Index: health, independence and social connectedness. By scanning four databases (Scopus, Web of Science, PubMed, and TRID), 3727 peer-reviewed papers published in the last decade were found, of which 57 met the inclusion criteria. The screening process was conducted following the PRISMA protocol and registered to the database PROSPERO, while the quality assessment was done using the Mixed Methods Appraisal Tool. More than 80% of the papers showed that an active mobility prevents psycho-physical harms, while only few papers study the relation of mobility with independence and social inclusion, to reduce the need for assistance and the related public expenditures. The findings of this review give important information both to transportation researchers and policymakers and companies, underlining the need for further research as well as investments in targeted age-friendly transport systems. The Covid-19 emergency has further underlined the importance of this issue, being the elderly one of the more disadvantaged and frailer social group.

Role for Physical Fitness in the Association between Age and Cognitive Function in Older Adults: A Mediation Analysis of the SABE Colombia Study

Objectives. We investigated the association between physical fitness and cognitive status. Further, we examined whether physical fitness mediates the association between cognitive functioning and aging. Design. Cross-sectional study. Setting. Urban and rural Colombian older adults. Methods. 4416 participants from the SABE study were included in the current analysis. Physical fitness was assessed with the handgrip test and the usual gait speed test. Cognitive status was evaluated through the Folstein Mini-Mental State Examination. A parallel mediation path was used to test the possible mediator role of physical fitness between aging and cognitive functioning. Results. Older adults with lower handgrip strength (HGS) were more likely to have mild-cognitive status than older adults with healthy HGS (OR = 1.53, 95% CI = 1.15; 2.02). In addition, older adults with a slower gait speed were more likely to have mild cognitive impairment (OR = 2.05, 95% CI = 1.54; 2.78). Age had an inverse relationship with cognitive function (β = −0.110, 95% CI = −0.130; −0.100) and it was also inversely associated with HGS (β = −0.003, 95% CI = −0.005; −0.002) and gait speed (β = −0.010, 95% CI = −0.011; −0.009). The indirect effects, which indicate that the effect of age on cognitive function is transmitted through mediators, showed that both gait speed (β = −0.028, 95% CI = −0.036; −0.020) and HGS (β = −0.014, 95% CI = −0.024; −0.005) were independent mediators of the detrimental effect of aging on cognitive function. Conclusions. Physical fitness mediates the effects of aging on cognitive functioning. Our findings suggest that physical activity can be a key factor to prevent cognitive deterioration during aging process.

Association Between Physical Performance and Cognitive Function in Older Adults Across Multiple Studies: A Pooled Analysis Study

Background and Objectives

While several studies have examined the association between cognitive and physical function, the consistency of these associations across functional contexts is unclear. The consistency of the association between cognitive and physical function performance was examined at baseline across 17 clinical studies with diverse and heterogeneous conditions such as overweight/obese, sedentary, at risk for a mobility disability, osteoarthritis, low vitamin D, or had signs of cognitive impairment.

Research Design and Methods

Data are from 1,388 adults 50 years and older who completed a cognitive and physical function assessment as part of a research study at the Wake Forest Alzheimer's Disease Research Center or the Wake Forest Older Americans Independence Center. Linear regression models were used to relate cognitive measures (Mini-Mental Status Examination, Montreal Cognitive Assessment, and the Digit Symbol Substitution Task) and physical measures (the Short Physical Performance Battery and hand grip strength) for the whole sample and treat each study as a fixed effect. All models controlled for age, sex, race, and body mass index.

Results

Overall, there was a significant association between higher scores on the Mini-Mental Status Examination (per standard deviation) and better physical function performance (Short Physical Performance Battery score b = 0.24, p < .001) and its components (gait speed, chair rise, and standing balance; ps < .05). Higher scores on the Montreal Cognitive Assessment produced similar results (Short Physical Performance Battery score b = 0.31, p ≤ .001), and higher scores on the Digit Symbol Substitution Task were also significantly associated with a better Short Physical Performance Battery score (b = 0.75, p < .001). The relationship between Digit Symbol Substitution Task and physical function performance demonstrated a stronger magnitude of association compared to the Mini-Mental Status Examination or Montreal Cognitive Assessment.

Discussion and Implications

Older adults with heterogeneous health conditions showed a consistent pattern between better cognitive function and better physical function performance with the strongest association among Digit Symbol Substitution Task scores.

Associations Between Declining Physical and Cognitive Functions in the Lothian Birth Cohort 1936

BACKGROUND

The ageing process is characterized by declines in physical and cognitive function. However, the relationship between these trajectories remains a topic of investigation.

METHODS

Using four data waves collected triennially between ages 70 and 79, we tested for associations between multiple cognitive ability domains (verbal memory, processing speed, and visuospatial ability) and physical functions (walking speed, grip strength, and lung function). We first tested for associations between linear declines in physical and cognitive functions over the entire 9-year study period, and then, for lead-lag coupling effects between 3-year changes in cognitive and physical functions.

RESULTS

Steeper linear decline in walking speed was moderately correlated with steeper linear declines in each cognitive domain. Steeper linear decline in grip strength was moderately correlated with steeper linear declines in verbal memory and processing speed. Lead-lag coupling models showed that decline in verbal memory was preceded by declines in walking speed and grip strength. By contrast, decline in grip strength was preceded by declines in processing speed and visuospatial ability, and decline in walking speed was preceded by decline in visuospatial ability. Following additional adjustment for covariates, only coupling effects from earlier decline in processing speed to later decline in grip strength remained significant (β = 0.545, p = .006).

CONCLUSION

Our findings provide further evidence of an association between cognitive and physical declines and point to the potential order in which these changes occur. Decline in processing speed in particular may serve as a unique early marker of declining upper body strength.

Motoric cognitive risk syndrome: Integration of two early harbingers of dementia in older adults

Dementia is characterized by a long preclinical phase that may last years to decades before the onset of mild cognitive impairment. Slow gait speed and subjective memory complaint commonly co-occur during this preclinical phase, and each is a strong independent predictor of cognitive decline and dementia. Motoric cognitive risk (MCR) syndrome is a pre-dementia syndrome that combines these two early harbingers of dementia. The risk of cognitive decline or dementia is stronger for MCR than for either slow gait speed or subjective memory complaint alone. Slow gait speed and subjective memory complaint have several common risk factors: cardiovascular disease, diabetes mellitus, abnormal cortisol profiles, low vitamin D levels, brain atrophy with decreased hippocampal volume, and increased deposition of beta-amyloid in the brain. The underlying pathogenesis of MCR remains poorly understood. Metabolomics and proteomics have great potential to provide new insights into biological pathways involved in MCR during the long preclinical phase preceding dementia.

A prospective study of focal brain atrophy, mobility and fitness

BACKGROUND

The parallel decline of mobility and cognition with ageing is explained in part by shared brain structural changes that are related to fitness. However, the temporal sequence between fitness, brain structural changes and mobility loss has not been fully evaluated.

METHODS

Participants were from the Baltimore Longitudinal Study of Aging, aged 60 or older, initially free of cognitive and mobility impairments, with repeated measures of fitness (400-m time), mobility (6-m gait speed) and neuroimaging markers over 4 years (n = 332). Neuroimaging markers included volumes of total brain, ventricles, frontal, parietal, temporal and subcortical motor areas, and corpus callosum. Autoregressive models were used to examine the temporal sequence of each brain volume with mobility and fitness, adjusted for age, sex, race, body mass index, height, education, intracranial volume and APOE ɛ4 status.

RESULTS

After adjustment, greater volumes of total brain and selected frontal, parietal and temporal areas, and corpus callosum were unidirectionally associated with future faster gait speed over and beyond cross-sectional and autoregressive associations. There were trends towards faster gait speed being associated with future greater hippocampus and precuneus. Higher fitness was unidirectionally associated with future greater parahippocampal gyrus and not with volumes in other areas. Smaller ventricle predicted future higher fitness.

CONCLUSION

Specific regional brain volumes predict future mobility impairment. Impaired mobility is a risk factor for future atrophy of hippocampus and precuneus. Maintaining fitness preserves parahippocampal gyrus volume. Findings provide new insight into the complex and bidirectional relationship between the parallel decline of mobility and cognition often observed in older persons.

Examining the Association between Life-Space Mobility and Cognitive Function in Older Adults: A Systematic Review

Purpose

The purpose of this review is to investigate the relationship between life-space mobility and cognition in older adults.

Methods

MEDLINE, Embase, CINAHL, and PsycINFO were searched through December 2018 for studies containing measures of life-space mobility and cognitive function. Two independent reviewers screened studies. Eligible studies were combined using a random-effects model, and heterogeneity was assessed using the I².

Results

Thirty-five articles were identified for review. A moderate and statistically significant association (pooled r = 0.30, 95% confidence interval 0.19 to 0.40.) was observed between life-space mobility and cognition among nine studies. Life-space mobility demonstrated small-to-moderate associations with domain-specific cognitive functioning, particularly executive function, learning, memory, and processing speed. Furthermore, individuals who had restricted life-space mobility (Life-Space Assessment ≤ 40) experienced a steeper decline in cognition (β = 0.56 and p = 0.0471) compared to those who did not (Life-Space Assessment ≥ 41).

Conclusion

This review examined the association between life-space mobility and cognitive function in older adults. The results suggest that a moderate relationship between life-space mobility and cognition exists, whether adjusted or unadjusted for covariates such as sociodemographics, mental health, functional capacity, and comorbidities.

A new physical-cognitive scale for assessment of frailty in Chinese Han elderly

Objective: To develop a physical- cognitive scale for assessment of frailty and compare the clinical features between the new scale and the conventional Fried criteria. Methods: 1757 individuals aged 70-84 were analyzed. Participants reporting three or more Fried phenotypes were grouped as frail patients (FP) whereas others as non-frail (NF). A score of Hasegawa's dementia scale (HDS-R) higher than 21.5 were classified as non-cognitive impairment group (NCI) group. By combining the cognitive and frailty criteria, participants manifesting three or more positive components out of the six were categorized into the Physical-cognitive frailty group (Pc-F) while others into non- Pc-F (Pc-NF). Results: Of all the participants, 46.7% (820) were males and 53.3% (937) were females. The mean age was 75.33 ± 3.90. 10.1% (178/1757) were evaluated as FP patients. The prevalence of CI was 53.2%; CI was much higher in the frail group (77.0%) than in the non-frail group (50.5%). Based on the new Pc-F scale, 163 out of 1579 NF participants were identified as Pc-F, and the prevalence of Pc-F reached 19.4% (341/1757). In the Pc-F group, there are more females, patients of advanced age, diabetes, stroke, CHD, CKD, metabolic syndrome, and high hs-CRP. Within the Pc-F group, patients with CI showed a higher incidence of exhaustion, low activity, weakness, and slowness than those without CI. Conclusions: Our study revealed a significantly worse status in frail participants with CI than without. Our new scale shows a stronger correlation between frailty and complications than the classic phenotype.

Cognitive Assessment of Older People: Do Sensory Function and Frailty Matter?

Background: To examine the associations of visual and hearing functions, and frailty with subjective memory complaints (SMCs) in a community primary care pilot project of older people aged 60 years and over. Methods: The study was conducted in 24 community centers. A total of 1949 community-dwelling older people aged between 60⁻97 years were evaluated for which detailed information regarding socio-demographics, lifestyle, and clinical factors were documented at baseline and an average of 12 months later. SMCs were assessed using the 5-item Abbreviated Memory Inventory for the Chinese (AMIC). Visual and hearing functions were measured with two separate single questions. Frailty was assessed using a simple frailty question (FRAIL). Results: At baseline, 1685 (74.6%) participants had reported at least 3 SMCs (AMIC score ≥ 3). Of the 573 participants without / with 1⁻2 SMCs (AMIC score = 0⁻2) at baseline, 75 had incomplete data regarding SMCs and 190 developed at least 3 SMCs after 12 months. After adjustments for age, sex, marital status, educational level, hypertension, and diabetes at baseline, poor vision (OR 2.2 95% CI 1.8⁻2.7), poor hearing (OR 2.2 95% CI 1.8⁻2.8), and frailty (OR 4.6 95% CI 3.1⁻6.7) at baseline were each significantly associated with an increased risk of at least 3 SMCs at follow-up. After a further adjustment for baseline SMCs, the associations remained significant. Similar results were obtained when incident SMCs and improvement in subjective memory were used as the outcome variables; and Conclusions: In the care of older people, detection of sensory impairment and frailty through screening may allow formulation of strategies to prevent or delay the onset of cognitive decline.

Hilliness and the Development of Walking Difficulties Among Community-Dwelling Older People

Objective: The objective of this study is to study the associations of objectively defined hilliness with the prevalence and incidence of walking difficulties among community-dwelling older adults, and to explore whether behavioral, health, or socioeconomic factors would fully or partially explain these associations. Method: Baseline interviews ( n = 848, 75-90 years) on difficulties in walking 500 m, frequency of moving through the neighborhood, and perceived hilliness as a barrier to outdoor mobility were conducted. Two-year follow-up interviews ( n = 551) on difficulties in walking 500 m were conducted among participants without baseline walking difficulties. Hilliness objectively defined as the mean slope in 500-m road network. Results: Logistic regression showed that hilliness was associated with incident walking difficulties at the 2-year follow-up (odds ratio [OR] = 1.66, 95% confidence interval [CI] = [1.09, 2.51]) but not with the prevalence of walking difficulties at baseline. Adding behavioral, health, or socioeconomic factors to the models did not markedly change the results. Discussion: Greater hilliness should be considered a risk factor for developing walking difficulties among older adults.

Comparing the Effects of Low-Protein and High-Carbohydrate Diets and Caloric Restriction on Brain Aging in Mice

Calorie restriction (CR) increases lifespan and improves brain health in mice. Ad libitum low-protein, high-carbohydrate (LPHC) diets also extend lifespan, but it is not known whether they are beneficial for brain health. We compared hippocampus biology and memory in mice subjected to 20% CR or provided ad libitum access to one of three LPHC diets or to a control diet. Patterns of RNA expression in the hippocampus of 15-month-old mice were similar between mice fed CR and LPHC diets when we looked at genes associated with longevity, cytokines, and dendrite morphogenesis. Nutrient-sensing proteins, including SIRT1, mTOR, and PGC1α, were also influenced by diet; however, the effects varied by sex. CR and LPHC diets were associated with increased dendritic spines in dentate gyrus neurons. Mice fed CR and LPHC diets had modest improvements in the Barnes maze and novel object recognition. LPHC diets recapitulate some of the benefits of CR on brain aging.

Walking Speed, Cognitive Function, and Dementia Risk in the English Longitudinal Study of Ageing

Objectives

To determine the relationships between walking speed, cognitive function, and the interaction between changes in these measures and dementia risk.

Design

Longitudinal observational study.

Setting

English Longitudinal Study of Ageing.

Participants

Individuals aged 60 and older (N=3,932).

Measurements

Walking speed and cognition were assessed at Waves 1 (2002–03) and 2 (2004–05) of the English Longitudinal Study of Ageing. New dementia cases were assessed from Wave 3 (2006–07) to Wave 7 (2014–15). The associations were modelled using Cox proportional hazards regression.

Results

Participants with faster baseline walking speeds were at lower risk of developing dementia (hazard ratio (HR)=0.36, 95% confidence interval (CI)=0.22–0.60). Those with a greater decline in walking speed from Wave 1 to 2 were at greater risk of developing dementia (HR=1.23, 95% CI=1.03–1.47). Participants with better baseline cognition (HR=0.42, 95% CI=0.34–0.54) were at lower risk of developing dementia. Those with a greater decline in cognition from Wave 1 to 2 were at greater risk of developing dementia (HR=1.78, 95% CI=1.53–2.06). Change in walking speed and change in cognition did not have an interactive effect on dementia risk (HR=1.01, 95% CI=0.88–1.17).

Conclusion

In this community‐dwelling sample of English adults, those with slower walking speeds and a greater decline in speed over time were at greater risk of developing dementia independent of changes in cognition. Further research is required to understand the mechanisms that may drive these associations.

See related editorial by https://doi.org/https://doi.org/10.1111/jgs.15368.

The Effects of Combinations of Cognitive Impairment and Pre-frailty on Adverse Outcomes from a Prospective Community-Based Cohort Study of Older Chinese People

Objectives

To examine how various combinations of cognitive impairment (overall performance and specific domains) and pre-frailty predict risks of adverse outcomes; and to determine whether cognitive frailty may be defined as the combination of cognitive impairment and the presence of pre-frailty.

Design

Community-based cohort study.

Participants

Chinese men and women (n = 3,491) aged 65+ without dementia, Parkinson’s disease and/or frailty at baseline.

Measurements

Frailty was characterized using the Cardiovascular Health Study criteria. Overall cognitive impairment was defined by a Cantonese Mini-Mental Status Examination (CMMSE) total score (<21/24/27, depending on participants’ educational levels); delayed recall impairment by a CMMSE delayed recall score (<3); and language and praxis impairment by a CMMSE language and praxis score (<9). Adverse outcomes included poor quality of life, physical limitation, increased cumulative hospital stay, and mortality.

Results

Compared to those who were robust and cognitively intact at baseline, those who were robust but cognitively impaired were more likely to develop pre-frailty/frailty after 4 years (P < 0.01). Compared to participants who were robust and cognitively intact at baseline, those who were pre-frail and with overall cognitive impairment had lower grip strength (P < 0.05), lower gait speed (P < 0.01), poorer lower limb strength (P < 0.01), and poorer delayed recall at year 4 [OR, 1.6; 95% confidence interval (CI), 1.2–2.3]. They were also associated with increased risks of poor quality of life (OR, 1.5; 95% CI, 1.1–2.2) and incident physical limitation at year 4 (OR, 1.8; 95% CI, 1.3–2.5), increased cumulative hospital stay at year 7 (OR, 1.5; 95% CI, 1.1–2.1), and mortality over an average of 12 years (OR, 1.5; 95% CI, 1.0–2.1) after adjustment for covariates. There was no significant difference in risks of adverse outcomes between participants who were pre-frail, with/without cognitive impairment at baseline. Similar results were obtained with delayed recall and language and praxis impairments.

Conclusion

Robust and cognitively impaired participants had higher risks of becoming pre-frail/frail over 4 years compared with those with normal cognition. Cognitive impairment characterized by the CMMSE overall score or its individual domain score improved the predictive power of pre-frailty for poor quality of life, incident physical limitation, increased cumulative hospital stay, and mortality. Our findings support to the concept that cognitive frailty may be defined as the occurrence of both cognitive impairment and pre-frailty, not necessarily progressing to dementia.

A development study and randomised feasibility trial of a tailored intervention to improve activity and reduce falls in older adults with mild cognitive impairment and mild dementia

BACKGROUND

People with dementia progressively lose abilities and are prone to falling. Exercise- and activity-based interventions hold the prospect of increasing abilities, reducing falls, and slowing decline in cognition. Current falls prevention approaches are poorly suited to people with dementia, however, and are of uncertain effectiveness. We used multiple sources, and a co-production approach, to develop a new intervention, which we will evaluate in a feasibility randomised controlled trial (RCT), with embedded adherence, process and economic analyses.

METHODS

We will recruit people with mild cognitive impairment or mild dementia from memory assessment clinics, and a family member or carer. We will randomise participants between a therapy programme with high intensity supervision over 12 months, a therapy programme with moderate intensity supervision over 3 months, and brief falls assessment and advice as a control intervention. The therapy programmes will be delivered at home by mental health specialist therapists and therapy assistants. We will measure activities of daily living, falls and a battery of intermediate and distal health status outcomes, including activity, balance, cognition, mood and quality of life. The main aim is to test recruitment and retention, intervention delivery, data collection and other trial processes in advance of a planned definitive RCT. We will also study motivation and adherence, and conduct a process evaluation to help understand why results occurred using mixed methods, including a qualitative interview study and scales measuring psychological, motivation and communication variables. We will undertake an economic study, including modelling of future impact and cost to end-of-life, and a social return on investment analysis.

DISCUSSION

In this study, we aim to better understand the practicalities of both intervention and research delivery, and to generate substantial new knowledge on motivation, adherence and the approach to economic analysis. This will enable us to refine a novel intervention to promote activity and safety after a diagnosis of dementia, which will be evaluated in a definitive randomised controlled trial.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT02874300; ISRCTN 10550694.

Vitamin B12 deficiency and impaired expression of amnionless during aging

BACKGROUND

Physical frailty and loss of mobility in elderly individuals lead to reduced independence, quality of life, and increased mortality. Vitamin B12 deficiency has been linked to several age-related chronic diseases, including in the musculo-skeletal system, where vitamin B12 deficiency is generally believed to be linked to poor nutritional intake. In the present study, we asked whether aging and frailty associate with altered vitamin B12 homeostasis in humans and investigated the underlying molecular mechanisms using preclinical models.

METHODS

We analysed a subset of the Singapore Longitudinal Aging Study and stratified 238 participants based on age and Fried frailty criteria. Levels of methyl-malonic acid (MMA), a marker for vitamin B12 deficiency, and amnionless, the vitamin B12 co-receptor that anchors the vitamin B12 transport complex to the membrane of epithelial cells, were measured in plasma. In addition, vitamin B12 levels and the molecular mechanisms of vitamin B12 uptake and excretion were analysed in ileum, kidney, liver, and blood using a rat model of natural aging where nutritional intake is fully controlled.

RESULTS

We demonstrate that aging and frailty are associated with a higher prevalence of functional vitamin B12 deficiency that can be detected by increased levels of MMA in blood (ρ = 0.25; P = 0.00013). The decline in circulating vitamin B12 levels is recapitulated in a rat model of natural aging where food composition and intake are stable. At the molecular level, these perturbations involve altered expression of amnionless in the ileum and kidney. Interestingly, we demonstrate that amnionless can be detected in serum where its levels increase during aging in both rodents and human (P = 3.3e-07 and 9.2e-07, respectively). Blood amnionless levels negatively correlate with vitamin B12 in rats (r²  = 0.305; P = 0.0042) and positively correlate with the vitamin B12 deficiency marker MMA in humans (ρ = 0.22; P = 0.00068).

CONCLUSIONS

Our results demonstrate that aging and frailty cause intrinsic vitamin B12 deficiencies, which can occur independently of nutritional intake. Mechanistically, vitamin B12 deficiency involves the physio-pathological decline of both the intestinal uptake and the renal reabsorption system for vitamin B12. Finally, amnionless is a novel biomarker which can detect perturbed vitamin B12 bioavailability during aging and physical frailty.

Walking speed decline in older adults is associated with elevated pro-BDNF in plasma extracellular vesicles

BACKGROUND

Brain-derived neurotrophic factor (BDNF) is produced by cleavage of proBDNF, and BDNF and proBDNF may play antagonistic roles in nervous system development, learning, memory and neuronal stress resistance. BDNF and proBDNF are present in blood, but the origin and relative contributions of soluble and extracellular vesicle (EV)-associated levels are unknown.

METHODS

In this study we used validated immunoassays to measure proBDNF and BDNF levels in plasma, total plasma EVs and a subpopulation of EVs enriched for neuronal origin (expressing the neuronal marker L1CAM) in 150 Baltimore Longitudinal Study of Aging participants with and without decline in walking speed (reflecting aging-associated motor decline).

RESULTS

Levels of BDNF and proBDNF were highest in L1CAM+ EVs. Participants with walking speed decline had higher levels of proBDNF in L1CAM+ EVs compared to non-decliners, but no differences in proBDNF levels in plasma and total EV.

CONCLUSIONS

Our findings suggest that levels of proBDNF and BDNF in circulating L1CAM+ EVs might be used as biomarkers for conditions involving altered BDNF signaling.