Joint trajectories of cognition and gait speed in Mexican American and European American older adults: The San Antonio longitudinal study of aging

Neuroimaging Correlates of 3 Distinct Physical-Cognitive Phenotypes in Cognitively Normal Older Adults: The Gothenburg H70 Cohort Study

BACKGROUND AND OBJECTIVES

Individuals aged 70 and older frequently experience an increased risk of deficits in both physical and cognitive functions. However, the natural progression and interrelationship of these deficits, as well as their neurologic correlates, remain unclear. We aimed to classify the data-driven physical-cognitive phenotypes and then investigate their associations with neuroimaging markers.

METHODS

This cross-sectional study included 70-year-old participants from the Gothenburg H70 Birth Cohort (2014-2016). Based on physical performance (grip strength, balance, walking speed, and chair stand) and cognitive measures (episodic memory, perceptual speed, executive function, verbal fluency, and visuospatial abilities), we applied latent class analysis to identify physical-cognitive phenotypes. Based on the brain MRI measurements, 3 groups of neuroimaging markers were involved-neurodegeneration, cerebral small vessel disease (cSVD), and microstructural white matter (WM) integrity. We performed multinomial logistic regressions to examine the differences between the physical-cognitive phenotypes.

RESULTS

In total, 1,140 participants (female: 53.3%) without dementia and disability were included in the study, with 721 (female: 52.2%) undergoing MRI scans. Three physical-cognitive phenotypes were identified: an "optimal" group characterized by high performance in both physical and cognitive functions, an "intermediate" group showing a slight reduction in both domains, and a "physical deficit" group marked by a significant reduction in physical performance. Compared with the optimal group, the other 2 groups were more likely to present with vascular risk factors. The physical deficit group had higher odds of experiencing depression compared with the intermediate group (adjusted odds ratio [aOR] 2.9, 95% CI 1.4-5.9). Compared with the optimal group, the odds of presenting all 3 severe neuroimaging markers were higher in both the intermediate (aOR 3.4, 95% CI 1.5-7.9) and physical deficit (aOR 10.3, 95% CI 2.4-45.0) groups.

DISCUSSION

This study highlights the variability in physical and cognitive performance among older adults and suggests that neuroimaging markers of neurodegeneration, cSVD, and microstructural WM integrity may account for these variations. Our findings indicate the potential for developing group-based strategies to prevent and manage age-related functional decline. Further research with larger sample sizes is needed to deepen our understanding of physical-cognitive decline patterns.

Temporal Sequence of Incident Mild Cognitive Impairment, Incident Parkinsonism, and Risk of Death in Unimpaired Community-Dwelling Older Adults

BACKGROUND

Mild cognitive impairment (MCI) and parkinsonism affect many older adults. The objective of this study was to determine the sequence of their occurrence and associated risk of death.

METHODS

A total of 1255 community-dwelling unimpaired participants from 2 epidemiological cohorts were examined annually. MCI was based on neuropsychological testing and parkinsonism was based on the motor portion of the modified Unified Parkinson's Disease Rating Scale. A multistate Cox proportional hazards model simultaneously examined incidences of MCI, parkinsonism, and death.

RESULTS

The average age at baseline was 76.5 years (standard deviation [SD] = 7.2) and 73% were female. Incident MCI occurred almost as commonly as incident parkinsonism, yet compared with no impairment, the risk of death was higher for MCI (hazard ratio [HR] = 1.82, 95% confidence interval [CI] = 1.34, 2.47), but it was not different for parkinsonism (HR = 1.29; 95% CI =0.95, 1.75). The risk of death for participants with incident MCI who progressed to parkinsonism (40%) was not significantly different from those with MCI alone (HR = 1.25, 95% CI = 0.93, 1.69). However, the risk of death for participants with incident parkinsonism who progressed to MCI (51%) was significantly higher than those who did not progress (HR = 1.67, 95% CI = 1.27, 2.18), indicating that the risk of death is highest with the incidence of MCI.

CONCLUSIONS

The varied patterns of sequential occurrence of cognitive and motor impairment and associated risk of death suggest much greater heterogeneity than previously recognized. Further work is needed to determine the biology underlying the temporal evolution of these phenotypes, and if identification of the various subtypes improves risk stratification.

A Scoping Review of Personal, Financial, and Environmental Determinants of Mobility Among Older Adults

OBJECTIVE

To synthesize available evidence of factors comprising the personal, financial, and environmental mobility determinants and their association with older adults' self-reported and performance-based mobility outcomes.

DATA SOURCES

PubMed, EMBASE, PsychINFO, Web of Science, AgeLine, Sociological Abstract, Allied and Complementary Medicine Database, and Cumulative Index to Nursing and Allied Health Literature databases search for articles published from January 2000 to December 2021.

STUDY SECTION

Using predefined inclusion and exclusion criteria, multiple reviewers independently screened 27,293 retrieved citations from databases, of which 422 articles underwent full-text screening, and 300 articles were extracted.

DATA EXTRACTION

The 300 articles' information, including study design, sample characteristics including sample size, mean age and sex, factors within each determinant, and their associations with mobility outcomes, were extracted.

DATA SYNTHESIS

Because of the heterogeneity of the reported associations, we followed Barnett et al's study protocol and reported associations between factors and mobility outcomes by analyses rather than by article to account for multiple associations generated in 1 article. Qualitative data were synthesized using content analysis. A total of 300 articles were included with 269 quantitative, 22 qualitative, and 9 mixed-method articles representing personal (n=80), and financial (n=1), environmental (n=98), more than 1 factor (n=121). The 278 quantitative and mixed-method articles reported 1270 analyses; 596 (46.9%) were positively and 220 (17.3%) were negatively associated with mobility outcomes among older adults. Personal (65.2%), financial (64.6%), and environmental factors (62.9%) were associated with mobility outcomes, mainly in the expected direction with few exceptions in environmental factors.

CONCLUSIONS

Gaps exist in understanding the effect of some environmental factors (eg, number and type of street connections) and the role of gender on older adults' walking outcomes. We have provided a comprehensive list of factors with each determinant, allowing the creation of core outcome set for a specific context, population, or other forms of mobility, for example, driving.

Gender and age influence the association between gait speed and mild cognitive impairment in community-dwelling Japanese older adults: from the Japan Prospective Studies Collaboration for Ageing and Dementia (JPSC-AD)

BACKGROUND

Studies have shown that decreased gait speed is associated with impaired cognitive function. However, whether this association is equivalent across ages or genders in the older population remains unclear. Thus, we examined the association between mild cognitive impairment (MCI) and gait speed emphasising the influence of age and gender.

METHODS

Overall, 8233 Japanese participants aged ≥65 years were enrolled in this cross-sectional study between 2016 and 2018. After stratification by gender and age group, the participants' gait speeds were divided into quintiles, and the difference in MCI prevalence at each gait speed quintile was calculated. Logistic regression analyses were performed to assess the odds of MCI for each quintile and to assess the influence of age and gender.

RESULTS

Males had a consistently higher prevalence of MCI than females. The odds of MCI were increased as gait speed decreased. Logistic regression analyses revealed that in the multivariable-adjusted model 2, the odds ratios (95% confidence interval; CI) for MCI were 2.02 (1.47-2.76) for females and 1.75 (1.29-2.38) for males in the slowest gait speed quintiles compared to the fastest quintile. In the stratified analyses, only males showed an age-dependent increase in the associations between gait speed and MCI, while females exhibited comparable associations across age groups.

CONCLUSIONS

Reduced gait speed was associated with increased odds of MCI, and this association may vary according to gender and age. Therefore, gait speed could serve as a valuable screening tool for MCI, with gender- and age-dependent clinical implications.

Nativity differences in the relationship between handgrip strength and cognitive impairment in older Mexican Americans over 20 years of follow-up

PURPOSE

To examine nativity differences in the relationship between handgrip strength (HGS) and cognitive impairment among Mexican Americans aged ≥ 65 years with normal or high cognitive function at baseline over a 20-year period.

METHODS

Prospective cohort study of 2,155 non-institutionalized Mexican Americans aged ≥ 65 years from the Hispanic Established Population for the Epidemiological Study of the Elderly) who scored ≥ 21 in the Mini Mental State Examination (MMSE) at baseline. Measures included socio-demographics, body mass index, medical conditions, depressive symptoms, physical function, disability, HGS quartiles (sex-adjusted), and MMSE. We used generalized estimating equation models to estimate the odds ratio (OR) and 95% Confidence Interval (CI) of cognitive impairment (MMSE < 21) as a function of HGS quartile by nativity and adjusted for covariates.

RESULTS

US-born and foreign-born participants in the 4th quartile (highest) of HGS at baseline had lower odds of cognitive impairment over time compared with those in the 1st (lowest) HGS quartile (OR=0.95, 95% CI=0.90-0.99 and OR=0.93, 95% CI=0.89-0.98, respectively), after controlling for all covariates. When we analyzed HGS quartiles as time-varying, we found that US-born participants in the 3rd and 4th HGS quartile had 25% and 30% lower odds of cognitive impairment, respectively, while foreign-born participants in the 3rd and 4th HGS quartile had 27% and 49% lower odds of cognitive impairment over time, respectively, after controlling for all covariates.

CONCLUSION

Foreign-born older Mexican Americans who performed high in HGS experienced 7% lower odds of cognitive impairment over time compared with US-born older Mexican Americans.

Age-Related Trajectories of General Fluid Cognition and Functional Decline in the Health and Retirement Study: A Bivariate Latent Growth Analysis

There have been few studies on associations between age-related declines in fluid cognition and functional ability in population-representative samples of middle-aged and older adults. We used a two-stage process (longitudinal factor analysis followed by structural growth modeling) to estimate bivariate trajectories of age-related changes in general fluid cognition (numeracy, category fluency, executive functioning, and recall memory) and functional limitation (difficulties in daily activities, instrumental activities, and mobility). Data came from the Health and Retirement Study (Waves 2010-2016; N = 14,489; ages 50-85 years). Cognitive ability declined on average by -0.05 SD between ages 50-70 years, then -0.28 SD from 70-85 years. Functional limitation increased on average by +0.22 SD between ages 50-70 years, then +0.68 SD from 70-85 years. Significant individual variation in cognitive and functional changes was observed across age windows. Importantly, cognitive decline in middle age (pre-age 70 years) was strongly correlated with increasing functional limitation (r = -.49, p < .001). After middle age, cognition declined independently of change in functional limitation. To our knowledge, this is the first study to estimate age-related changes in fluid cognitive measures introduced in the HRS between 2010-2016.

Tracking clusters of patients over time enables extracting information from medico-administrative databases

CONTEXT

Identifying clusters (i.e., subgroups) of patients from the analysis of medico-administrative databases is particularly important to better understand disease heterogeneity. However, these databases contain different types of longitudinal variables which are measured over different follow-up periods, generating truncated data. It is therefore fundamental to develop clustering approaches that can handle this type of data.

OBJECTIVE

We propose here cluster-tracking approaches to identify clusters of patients from truncated longitudinal data contained in medico-administrative databases.

MATERIAL AND METHODS

We first cluster patients at each age. We then track the identified clusters over ages to construct cluster-trajectories. We compared our novel approaches with three classical longitudinal clustering approaches by calculating the silhouette score. As a use-case, we analyzed antithrombotic drugs used from 2008 to 2018 contained in the Échantillon Généraliste des Bénéficiaires (EGB), a French national cohort.

RESULTS

Our cluster-tracking approaches allow us to identify several cluster-trajectories with clinical significance without any imputation of data. The comparison of the silhouette scores obtained with the different approaches highlights the better performances of the cluster-tracking approaches.

CONCLUSION

The cluster-tracking approaches are a novel and efficient alternative to identify patient clusters from medico-administrative databases by taking into account their specificities.

Relative Trajectories of Gait and Cognitive Decline in Aging

BACKGROUND

Gait and cognition decline with advancing age, and presage the onset of dementia. Yet, the relative trajectories of gait and cognitive decline in aging are poorly understood-particularly among those with the motoric cognitive risk (MCR) syndrome. This study compared changes in simple and complex gait performance and cognition, as a function of age and MCR.

METHODS

We examined gait and cognitive functions of 1 095 LonGenity study participants (mean age = 75.4 ± 6.7 years) with up to 12 years of annual follow-up. Participants were of Ashkenazi Jewish descent, free of dementia, ambulatory, and had a 12.2% MCR prevalence at baseline. Gait speed was measured at usual pace walking (single-task walking, STW-speed) and walking while talking (WWT-speed). Eleven neuropsychological test scores were examined separately, and as a global cognition composite. Linear mixed-effects models adjusted for baseline sex, education, parental longevity, cognitive impairment, and global health were used to estimate changes in gait and cognition, as a function of age and MCR.

RESULTS

STW-speed, WWT-speed, and cognitive tests performance declined in a nonlinear (accelerating) fashion with age. STW-speed declined faster than WWT-speed and cognitive test scores. People with MCR showed faster rates of decline on figure copy and phonemic fluency.

CONCLUSIONS

Gait declines at a faster rate than cognition in aging. People with MCR are susceptible to faster decline in visuospatial, executive, and language functions. This study adds important knowledge of trajectories of gait and cognitive decline in aging, and identifies MCR as a risk factor for accelerated cognitive decline.

Mid-life epigenetic age, neuroimaging brain age, and cognitive function: coronary artery risk development in young adults (CARDIA) study

The proportion of aging populations affected by dementia is increasing. There is an urgent need to identify biological aging markers in mid-life before symptoms of age-related dementia present for early intervention to delay the cognitive decline and the onset of dementia. In this cohort study involving 1,676 healthy participants (mean age 40) with up to 15 years of follow up, we evaluated the associations between cognitive function and two classes of novel biological aging markers: blood-based epigenetic aging and neuroimaging-based brain aging. Both accelerated epigenetic aging and brain aging were prospectively associated with worse cognitive outcomes. Specifically, every year faster epigenetic or brain aging was on average associated with 0.19-0.28 higher (worse) Stroop score, 0.04-0.05 lower (worse) RAVLT score, and 0.23-0.45 lower (worse) DSST (all false-discovery-rate-adjusted p <0.05). While epigenetic aging is a more stable biomarker with strong long-term predictive performance for cognitive function, brain aging biomarker may change more dynamically in temporal association with cognitive decline. The combined model using epigenetic and brain aging markers achieved the highest accuracy (AUC: 0.68, p<0.001) in predicting global cognitive function status. Accelerated epigenetic age and brain age at midlife may aid timely identification of individuals at risk for accelerated cognitive decline and promote the development of interventions to preserve optimal functioning across the lifespan.

Analyzing Sensor-Based Individual and Population Behavior Patterns via Inverse Reinforcement Learning

Digital markers of behavior can be continuously created, in everyday settings, using time series data collected by ambient sensors. The goal of this work was to perform individual- and population-level behavior analysis from such time series sensor data. In this paper, we introduce a novel algorithm-Resident Relative Entropy-Inverse Reinforcement Learning (RRE-IRL)-to perform an analysis of a single smart home resident or a group of residents, using inverse reinforcement learning. By employing this method, we learnt an individual's behavioral routine preferences. We then analyzed daily routines for an individual and for eight smart home residents grouped by health diagnoses. We observed that the behavioral routine preferences changed over time. Specifically, the probability that the observed behavior was the same at the beginning of data collection as it was at the end (months later) was lower for residents experiencing cognitive decline than for cognitively healthy residents. When comparing aggregated behavior between groups of residents from the two diagnosis groups, the behavioral difference was even greater. Furthermore, the behavior preferences were used by a random forest classifier to predict a resident's cognitive health diagnosis, with an accuracy of 0.84.

Highways to Ageing - Linking life course SEP to multivariate trajectories of health outcomes in older adults

OBJECTIVES

Ageing is a temporal, multi-faceted process subject to interacting factors. In this study, we used life course and multidimensional approaches to elucidate the association between socioeconomic forces across a lifetime and the developmental origins in health and disease of the Mexican elderly.

METHODS

Data stemmed from the Mexican Health and Ageing Study, constituting a sample of older adults (N= 5169, ≥50 years). With retrospective information on early, intermediary and contemporaneous socioeconomic indicators, life course typologies of socioeconomic position were identified using Latent Class Analysis. Based on prospective data of functional mobility, number of chronic conditions and self-rated health, multivariate trajectories of health outcomes were uncovered with Group Based Trajectory Model. Links between the extracted SEP and multivariate health latent constructs were explored with multinomial logistic regression.

RESULTS

Life course SEP classes were heterogeneous, yet a large proportion of subjects was characterized by persistent socioeconomic adversity throughout life. The health outcomes' patterns of co-evolution were diverse too, shedding light on the nature of their developmental links, while revealing variable synchronicity in their temporal decline. A graded association was observed between the life course SEP classes and ageing trajectories.

CONCLUSION

The results primarily backed the cumulative advantage/disadvantage life course framework, while finding some indication for age as a leveller hypothesis. Variability in patterns of dynamic co-action among the health outcomes depicts ageing as a naturally variable process of interconnected changes. Life course evidence for the ways socio-economic forces are differentially linked to distinct developmental profiles of ageing is provided.