Cognitive Function In Older Adults Research Articles

Neural mechanisms of the relationship between aerobic fitness and working memory in older adults: An fNIRS study

Abstract A growing number of studies have revealed that higher aerobic fitness is associated with better working memory (WM) performance in older adults. However, the underlying functional neural mechanisms of this association remain under debate. It has been reported that aging increases recruitment of the prefrontal cortex (PFC) during cognitive tasks, and that this is associated with task performance in a compensatory manner. Therefore, this study aimed to clarify the prefrontal activation pattern that is associated with the relationship between aerobic fitness and WM performance in older adults, focusing on age-related extended prefrontal recruitment. Forty-seven older adults (65–74 years, 29 females) and 49 younger adults (18–24 years, 23 female) performed verbal and spatial n-back tasks, which included 0-, 1-, and 2-back conditions. Reaction time (RT) and accuracy (ACC) were assessed as indices of task performance. Prefrontal activation during the experimental tasks was monitored using functional near-infrared spectroscopy (fNIRS) and analyzed using an adaptive GLM method. We compared task performance and prefrontal activation between age groups to find age-related prefrontal activation patterns. Only older adults underwent a graded exercise test (GXT) to determine their ventilation thresholds (VT) as a measure of aerobic fitness, and, subsequently, the relationships among aerobic fitness, n-back task performance, and prefrontal activation in older adults were examined using correlation analysis and mediation analysis controlling for possible covariates. A comparison of task performance between groups revealed that older adults had slower RT and lower ACC than did younger adults, especially in the higher WM load 2-back condition. Group comparisons of prefrontal activation showed that older adults exhibited additional or greater activation than younger adults mainly in the ventrolateral PFC (VLPFC) and front polar area (FPA) in both the verbal and spatial 2-back conditions. Correlation analysis showed a relationship between higher VT, shorter RT for the verbal 2-back condition, and greater prefrontal activation of the bilateral FPA and right VLPFC during verbal 2-back conditions in older adults. In addition, mediation analyses indicated the possibility of a mediation effect of the prefrontal activation on the relationship between VT and RT for the verbal 2-back condition. These results suggest that older adults with higher aerobic fitness levels recruited more extended PFC regions, possibly for compensatory activation, to enhance their performance of the verbal n-back task. This study sheds light on the neural mechanisms underpinning the relationship between aerobic fitness and cognitive function in older adults.

Effect of digital game intervention on cognitive functions in older adults: a multiple baseline single case experimental design study

BackgroundResidents in nursing homes are prone to cognitive decline affecting memory, visuospatial cognition, and executive functions. Cognitive decline can lead to dementia, necessitating prioritized intervention.MethodsThe current study aimed to investigate whether an intervention using a digital game was effective for preserving and improving the cognitive function of residents in nursing homes. An intervention study was conducted using a single-case AB design with multiple baselines. The participants in the study were five older adults aged 65 and over who do not play digital games regularly. The study ran for 15 weeks, including a baseline (phase A) and an intervention phase (phase B). Phase A had five baselines (5 to 9 weeks) with random participant assignment. In phase B, participants engaged in a digital game (Space Invaders) individually. Cognitive function was assessed as the outcome, measured using the Brain Assessment (performed on a tablet through the Internet) at 16 measurement points. Four of five participants (two female and two male) were included in the analysis, using visual inspection and Bayesian statistics with multi-level modeling.ResultsVisual inspection of the graphs revealed cognitive function score improvements after the intervention for most layers in terms of memory of numbers, memory of words, mental rotation test (visuospatial ability), and total scores in the Brain Assessment. These effects were also significant in the analysis by multi-level modeling.ConclusionsThe results suggest that the use of digital games may be effective for preserving and improving cognitive function among residents of nursing home.Trial registrationThis study was registered in the University Hospital Medical Information Network Clinical Trials Registry (UMIN000048677; public title: Effect of a Digital Game Intervention for Cognitive Functions in Older People; registration date: August 30, 2022).

An analysis of factors influencing cognitive dysfunction among older adults in Northwest China based on logistic regression and decision tree modelling

BackgroundCognitive dysfunction is one of the leading causes of disability and dependence in older adults and is a major economic burden on the public health system. The aim of this study was to investigate the risk factors for cognitive dysfunction and their predictive value in older adults in Northwest China.MethodsA cross-sectional study was conducted using a multistage sampling method. The questionnaires were distributed through the Elderly Disability Monitoring Platform to older adults aged 60 years and above in Northwest China, who were divided into cognitive dysfunction and normal cognitive function groups. In addition to univariate analyses, logistic regression and decision tree modelling were used to construct a model to identify factors that can predict the occurrence of cognitive dysfunction in older adults.ResultsA total of 12,494 valid questionnaires were collected, including 2617 from participants in the cognitive dysfunction group and 9877 from participants in the normal cognitive function group. Univariate analysis revealed that ethnicity, BMI, age, educational attainment, marital status, type of residence, residency status, current work status, main economic source, type of chronic disease, long-term use of medication, alcohol consumption, participation in social activities, exercise status, social support, total scores on the Balanced Test Assessment, total scores on the Gait Speed Assessment total score, and activities of daily living (ADL) were significantly different between the two groups (all P < 0.05). According to logistic regression analyses, ethnicity, BMI, educational attainment, marital status, residency, main source of income, chronic diseases, annual medical examination, alcohol consumption, exercise status, total scores on the Balanced Test Assessment, and activities of daily living (ADLs) were found to influence cognitive dysfunction in older adults (all P < 0.05). In the decision tree model, the ability to perform activities of daily living was the root node, followed by total scores on the Balanced Test Assessment, marital status, educational attainment, age, annual medical examination, and ethnicity.ConclusionsTraditional risk factors (including BMI, literacy, and alcohol consumption) and potentially modifiable risk factors (including balance function, ability to care for oneself in daily life, and widowhood) have a significant impact on the increased risk of cognitive dysfunction in older adults in Northwest China. The use of decision tree models can help health care workers better assess cognitive function in older adults and develop personalized interventions. Further research could help to gain insight into the mechanisms of cognitive dysfunction and provide new avenues for prevention and intervention.

Optimizing the physical activity intervention for older adults with mild cognitive impairment: a factorial randomized trial

BackgroundPhysical activity (PA) intervention is one of the most effective interventions to promote cognitive function of older adults with mild cognitive impairment (MCI). However, the level of PA remains low. Based on the two core interventions (X-CircuiT and health education), this study aimed to examine the effect of three implementation strategies (viz., role modeling, goal-setting, and reminding) on the PA level among older adults with MCI using the multiphase optimization strategy (MOST).MethodsParticipants were randomized into one of eight conditions in a factorial design involving three factors with two levels: (i) role modeling (on vs. off); (ii) goal-setting (on vs. off); and (iii) reminding (on vs. off). The primary outcome was PA level at 12 weeks. The secondary outcomes were cognitive function, self-efficacy, and cost-effectiveness at 12 weeks. The intention-to-treat (ITT) analysis was performed as the main analysis and the per-protocol (PP) analysis as the sensitivity analysis.ResultsA total of 107 participants were included and randomly assigned into three groups, each receiving different implementation strategies. The results of the multivariate regression analysis showed that the three implementation strategies, namely, reminding (B = 0.31, p &amp;lt; 0.01), role modeling (B = 0.21, p &amp;lt; 0.01), and goal-setting (B = 0.19, p &amp;lt; 0.01), could significantly improve PA level. Specifically, it was found that role modeling (B = 0.68, p = 0.03) could significantly improve cognitive function. There were no significant interactions among the three implementation strategies. Role modeling was the most cost-effective strategy, costing 93.41 RMB for one unit of PA.ConclusionsRole modeling was likely to be the best implementation strategy. The value-based and cost-effective PA intervention package could include the core intervention (X-CircuiT and health education) and implementation strategy (role modeling).Clinical Trial Registrationhttps://www.chictr.org.cn, The study was retrospectively registered on 30 June 2022 (ChiCTR2200061693).

Latent Class Analysis of Sleep in Mild Cognitive Impairment Patients and its Influencing Factors

Background: Individuals with mild cognitive impairment (MCI) frequently experience sleep disorders, which may elevate the risk of developing Alzheimer’s disease. Yet, sleep types in MCI patients and the factors influencing them have not been sufficiently investigated. Objective: The objective of this study was to explore potential sleep typing and its influencing factors in patients with MCI using latent class analysis. Methods: A cross-sectional survey was conducted in Jiangsu Province, China. Cognitive function in older adults was assessed using neuropsychological tests, including the Montreal Cognitive Assessment Scale-Beijing version (MoCA), the Mini-Mental State Examination (MMSE), the Activities of Daily Living Scale (ADL), and the Clinical Dementia Rating Scale (CDR). Sleep quality was evaluated using the Pittsburgh Sleep Quality Index (PSQI). Latent class analysis based on PSQI scores and multinomial logistic regression analyses were employed to explore the influencing factors of sleep typing. Results: The study included a total of 611 patients with MCI. Latent class analysis identified three latent classes to categorize the sleep patterns of MCI patients: the good sleep type (56.6%), the insufficient sleep type (29.6%), and the difficulty falling asleep type (13.7%). Potential sleep typing is influenced by gender, chronic disease, physical exercise, social activity, brain exercise, smoking, frailty, subjective cognitive status, and global cognitive function. Conclusions: The findings of this study underscore the notable heterogeneity in the sleep patterns of patients with MCI. Future research may provide targeted prevention and interventions to address the characteristics and influencing factors of patients with different subtypes of sleep MCI.

LEGACY EFFECT OF EXERCISE TRAINING TRIALS ON COGNITION IN OLDER ADULTS: SYSTEMATIC REVIEW AND META-ANALYSIS

INTRODUCTION &amp; AIMS Exercise training trials consistently show efficacy for improving cognitive outcome in older adults, especially when the intervention is supervised. However, whether this improvement in cognition is sustained long-term (i.e. a legacy effect) is unknown. While this is likely impacted by long-term adherence to exercise, the legacy effect of exercise training trials on cognition has not been established. Therefore, the aim of this study was to review the literature and investigate the legacy effect of an exercise trial on cognitive function in older adults. METHODS A systematic review of the literature published in English was conducted in PubMed, Scopus, CINAHL, SPORTdiscus, Web of Science and Cochrane Central Register of Controlled Trials electronic databases. Study screening and data extraction were undertaken by two independent researchers. The main inclusion criteria were randomised controlled trial design with non-exercise control, older adult cohort (average age ≥50 years), supervised exercise intervention and cognitive assessments at post-trial and follow up (≥3 months). Pairwise random-effects restricted maximum likelihood meta-analysis estimated the standardised mean difference (Hedges’ g) between intervention and control groups for each cognitive function outcomes at post-trial and follow-up. RESULTS A total of 12,539 articles were screened with 21 trials (n=2,504 participants aged 75.2±6.4 and mostly (56%) female) included in a meta-analysis. After 5.2±3.2 months, a legacy effect was seen with a small-to-moderate between-group effect for the cognitive domain of executive function favouring the exercise interventions (SMD=0.30, 95% CI 0.11 to 0.49; p=0.002). No effect was observed for other cognitive domains. The Cochrane risk-of-bias tool for randomized trials (RoB2) tool identified that 73.7% of the trials had “some concerns” and 26.3% had high risk for bias. CONCLUSION In older adults who received an exercise intervention there was a small-to-moderate legacy effect for improved executive function compared to controls, five months after trial completion.

Longitudinal examination of cognitive function in older adults after the death of a child

This study examined the relationship between the death of a child and cognitive function, considering how this association varies with the timing and number of losses. Utilizing four waves of the China Health and Retirement Longitudinal Study, linear mixed models assessed the impact of child loss on cognition, while mediation analysis was conducted using the Karlson-Holm-Breen method. Findings indicate a detrimental effect of child loss on cognitive function, particularly for losses occurring before age 30 and after age 60. A dose-response relationship was noted, suggesting greater cognitive decline with increasing instances of child loss. Mediation analysis revealed that psychological distress, physical functioning limitations, and social engagement partly explain this link. Moreover, the negative effect was more significant in mothers. These insights underscore the need for targeted support and cognitive monitoring for bereaved parents.

Superoxide Dismutase Modified the Association of Serum Malondialdehyde Levels with Cognitive Decline Among Older Adults: Findings from the Chinese Longitudinal Healthy Longevity Survey.

Numerous studies have investigated the correlation between malondialdehyde (MDA) and cognitive decline. However, limited research has explored the interplay between superoxide dismutase (SOD), C-reactive protein (CRP), and MDA. This study aims to scrutinize the association between MDA and cognitive function in older adults, while also elucidating the roles of SOD and CRP within this relationship. Utilizing data from the Chinese Longitudinal Healthy Longevity Survey (CLHLS) spanning 2008-2009, 2011-2012, and 2014, this study included 2,696 eligible subjects. Cognitive function was evaluated using the Chinese version of the Mini-Mental State Examination (MMSE). Linear mixed-effects models were employed to examine the links between MDA, SOD, CRP, and their interactions with cognitive function. Elevated serum levels of MDA and CRP, as well as decreased serum SOD levels, were related to decreased cognitive function (β= -0.220 and -0.346, 95% CI: -0.399, -0.041 and -0.526, -0.167 for MDA and CRP; β= 0.384, 95% CI: 0.204, 0.564 for SOD). Notably, a significant interaction between MDA and SOD was detected (p = 0.001). An increase per standard deviation in serum MDA levels was significantly associated with a 0.347-point lower MMSE score only in participants with normal cognitive function and high SOD levels (β= -0.347, 95% CI: -0.497, -0.197; p <  0.001). Elevated serum MDA levels in the normal population with high SOD levels suggested diminished cognitive performance. Combining MDA with SOD could be pivotal in identifying older adults at risk of cognitive decline in clinical settings.

Association of hemoglobin-to-red blood cell distribution width ratio and cognition: A cross-sectional study

PurposeThis study aimed to investigate the association between hemoglobin-to-red blood cell distribution width ratio (HRR) and cognitive function. MethodsData, including cognition assessment, general characteristics, lifestyle attributes, disease-related factors, and blood indicators, were extracted from older people from the National Health and Nutrition Examination Survey (NHANES) 2011–2014 database. Statistical analysis included the Mann-Whitney U test, chi-square test, spearman correlation, and multiple linear regression. ResultsA total of 2452 participants were included, with 631(25.7 %) identified as having low-level cognition. HRR was significantly lower in the lower cognition group (P < 0.001) and positively associated with cognition score (P < 0.001). Multiple linear logistic regression analysis indicated that HRR remained associated with cognition even after adjusting for general characteristics, lifestyle attributes, disease-related factors, and blood indicators (P = 0.046). ConclusionLower HRR is an independent risk factor for low cognitive performance in older adults. However, further investigation is needed to elucidate the precise mechanism underlying the impact of HRR on cognitive function.

Accelerated epigenetic age is associated with whole-brain functional connectivity and impaired cognitive performance in older adults

While chronological age is a strong predictor for health-related risk factors, it is an incomplete metric that fails to fully characterize the unique aging process of individuals with different genetic makeup, neurodevelopment, and environmental experiences. Recent advances in epigenomic array technologies have made it possible to generate DNA methylation-based biomarkers of biological aging, which may be useful in predicting a myriad of cognitive abilities and functional brain network organization across older individuals. It is currently unclear which cognitive domains are negatively correlated with epigenetic age above and beyond chronological age, and it is unknown if functional brain organization is an important mechanism for explaining these associations. In this study, individuals with accelerated epigenetic age (i.e. AgeAccelGrim) performed worse on tasks that spanned a wide variety of cognitive faculties including both fluid and crystallized intelligence (N = 103, average age = 68.98 years, 73 females, 30 males). Additionally, fMRI connectome-based predictive models suggested a mediating mechanism of functional connectivity on epigenetic age acceleration-cognition associations primarily in medial temporal lobe and limbic structures. This research highlights the important role of epigenetic aging processes on the development and maintenance of healthy cognitive capacities and function of the aging brain.

Associations of Heavy Metals with Cognitive Function: An Epigenome-Wide View of DNA Methylation and Mediation Analysis.

Exposure to heavy metals has been reported to be associated with impaired cognitive function, but the underlying mechanisms remain unclear. This pilot study aimed to identify key heavy metal elements associated with cognitive function and further explore the potential mediating role of metal-related DNA methylation. Blood levels of arsenic, cadmium, lead, copper, manganese, and zinc and genome-wide DNA methylations were separately detected in peripheral blood in 155 older adults. Cognitive function was evaluated using the Mini-Mental State Examination (MMSE). Least absolute shrinkage and selection operator penalized regression and Bayesian kernel machine regression were used to identify metals associated with cognitive function. An epigenome-wide association study examined the DNA methylation profile of the identified metal, and mediation analysis investigated its mediating role. The MMSE scores showed a significant decrease of 1.61 (95% confidence interval [CI]: -2.64, -0.59) with each 1 standard deviation increase in ln-transformed arsenic level; this association was significant in multiple-metal models and dominated the overall negative effect of 6 heavy metal mixture on cognitive function. Seventy-three differentially methylated positions were associated with blood arsenic (p < 1.0 × 10-5). The methylation levels at cg05226051 (annotated to TDRD3) and cg18886932 (annotated to GAL3ST3) mediated 24.8% and 25.5% of the association between blood arsenic and cognitive function, respectively (all p < 0.05). Blood arsenic levels displayed a negative association with the cognitive function of older adults. This finding shows that arsenic-related DNA methylation alterations are critical partial mediators that may serve as potential biomarkers for further mechanism-related studies. ANN NEUROL 2024.

Subjective sleep more predictive of global cognitive function than objective sleep in older adults: A specification curve analysis

ObjectivesSleep is associated with cognitive function in older adults. In the current study, we examined this relationship from subjective and objective perspectives, and determined the robustness and dimensional specificity of the associations using a comprehensive modelling approach. MethodsMultiple dimensions of subjective (sleep quality and daytime sleepiness) and objective sleep (sleep stages, sleep parameters, sleep spindles, and slow oscillations), as well as subjectively reported and objectively measured cognitive function were collected from 55 older adults. Specification curve analysis was used to examine the robustness of correlations for the effects of sleep on cognitive function. ResultsRobust associations were found between sleep and objectively measured cognitive function, but not with subjective cognitive complaints. In addition, subjective sleep showed robust and consistent associations with global cognitive function, whereas objective sleep showed a more domain-specific association with episodic memory. Specifically, subjective sleep quality and daytime sleepiness correlated with global cognitive function, and objective sleep parameters correlated with episodic memory. ConclusionsOverall, associations between sleep and cognitive function in older adults depend on how they are measured and which specific dimensions of sleep and domains of cognitive function are considered. It highlights the importance of focusing on specific associations to ameliorate the detrimental effects of sleep disturbance on cognitive function in later life.

Effects of dual-task resistance exercise on cognition, mood, depression, functional fitness, and activities of daily living in older adults with cognitive impairment: a single-blinded, randomized controlled trial

BackgroundRegular exercise is emphasized for the improvement of functional capacity and independence of older adults. This study aimed to compare the effects of a dual-task resistance exercise program and resistance exercise on cognition, mood, depression, physical function, and activities of daily living (ADL) in older adults with cognitive impairment.MethodsA total of 44 older adults participated in the study. Participants were randomly allocated to an experimental group (n = 22) performing a dual-task resistance exercise program for cognitive function improvement and a control group (n = 22) performing a resistance exercise program. Both groups performed the exercise for 40 min per session, three times a week, for 6 weeks (18 sessions). Cognition, mood, depression, functional fitness, and ADL were quantified before and after the intervention using the Mini-Mental State Examination (MMSE), profile of mood states (POMS), geriatric depression scale (GDS), senior fitness test (SFT), and Korean version of ADL, respectively.ResultsThere was a significant time and group interaction on the MMSE (p = 0.044). There were no significant time and group interactions in the POMS, GDS, SFT, or ADL. Cognitive function (p < 0.001), mood (p < 0.001), depression (p < 0.001), functional fitness (p < 0.001), and ADL (p < 0.001) significantly improved after dual-task resistance exercise, and cognitive function (p < 0.001), mood (p < 0.001), depression (p < 0.001), functional fitness (p < 0.001), and ADL (p < 0.001) significantly improved after resistance exercise.ConclusionsDual-task resistance exercise is more effective than resistance exercise in improving cognitive function in older adults with cognitive impairment. Both dual-task resistance exercise and resistance exercise improves mood, depression, functional fitness, and ADL after the intervention. We propose using dual-task resistance exercises for cognitive and physical health management in the older adults with cognitive impairment.Trial registrationThis study was registered with the Clinical Research Information Service (WHO International Clinical Trials Registry Platform) (Registration ID, KCT0005389; Registration date, 09/09/2020).

The association between waist-to-height ratio and cognitive function in older adults

ABSTRACT Objectives The waist-to-height ratio (WHtR) is a simple, practical, and effective tool used to assess central obesity. Despite its usefulness, few studies have investigated the association between WHtR and cognitive function among older adults in the United States. This study aims to investigate the associations between WHtR and cognitive function. Methods The study sample comprised adults who participated in the National Health and Nutrition Examination Survey (NHANES) between 2011 and 2014. WHtR was calculated from measured waist circumference and height. Cognitive function was assessed using the digit symbol substitution test. A weighted multiple linear regression analysis was performed to evaluate the association between WHtR and cognitive function, with smooth curve fitting applied to detect non-linearities. Results Our analysis included 1709 participants over the age of 65. After adjusting for potential confounders, WHtR was found to have a negative association with cognitive function (β = −36.91, 95% CI: −54.54 to −19.29, P < 0.001). Subgroup analyzes stratified by sex and race showed that the negative correlation of WHtR with cognitive function remained in both men and women, as well as in non-Hispanic white and other races. Among women, the association between WHtR and cognitive function followed an inverted U-shaped curve, with an inflection point of 0.68. Conclusion This study provides evidence of a negative association between WHtR and cognitive function in older adults. These findings suggest that in advanced age, central obesity may have negative implications for cognitive function.

Changes in essentialist beliefs about cognitive aging predicts changes in mental health: Evidence from a 10-year longitudinal study.

The belief that aging-related cognitive decline is inevitable is associated with impaired cognitive performance of older adults. Little is, however, known about the association between changes in essentialist beliefs about cognitive aging and mental health in the long term and among both younger and older adults. From a theoretical perspective, it would be expected that changes in essentialist beliefs about cognitive aging predict changes in mental health among older adults compared to younger adults. These differential associations have not yet been prospectively investigated. Using longitudinal data, the association between changes in essentialist beliefs about cognitive aging and mental health outcomes and the moderation effect of age were assessed. Mental health includes well-being and mental illness (depression, anxiety, and panic symptoms). Data from adult participants (n = 4,963 with a mean age of 55.41 years, range 28-84 years) in a U.S. national longitudinal study were analyzed. A series of two-wave latent change score models indicated that changes in essentialist beliefs about cognitive aging are associated with changes in well-being and mental illness. Age did not moderate the relationship between changes in essentialist beliefs about aging and changes in mental health (i.e., mental illness and well-being). The present study highlights change-to-change dynamics between essentialist beliefs about cognitive aging and mental health, regardless of age. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Exploring the Relationship of Leisure Travel with Loneliness, Depression, and Cognitive Function in Older Adults.

Loneliness, depression, and cognitive decline are pressing concerns among older adults. This study examines the association between leisure travel participation and these health outcomes in older adults, aiming to provide further evidence of the benefits of leisure travel. Using nationally representative historical data from the 2006 household survey of the Health and Retirement Study, this study conducted a series of regression analyses to investigate the relationship between traveling and the three health outcomes, adjusting for age, sex, race, marital status, education, total wealth, annual income, and difficulty with daily activities. The results reveal that travel patterns in terms of distance are significantly associated with loneliness, depression, and cognitive function. Long-distance travel is positively related to higher cognitive function and a reduction in depressive symptoms, along with lower levels of loneliness, reinforcing the notion that leisure travel can potentially act as a catalyst for improved cognitive and mental health by offering opportunities for enhancing social connections and forming new relationships. The findings on the relationships between participation in leisure travel and mental and cognitive health contribute to the body of evidence supporting the therapeutic value of leisure travel in promoting healthy aging and enhancing the overall well-being in older adults.

Association between the circulating very long-chain saturated fatty acid and cognitive function in older adults: findings from the NHANES

BackgroundAge-related cognitive decline has a significant impact on the health and longevity of older adults. Circulating very long-chain saturated fatty acids (VLSFAs) may actively contribute to the improvement of cognitive function. The objective of this study was to investigate the associations between arachidic acid (20:0), docosanoic acid (22:0), tricosanoic acid (23:0), and lignoceric acid (24:0) with cognitive function in older adults.MethodsThis study used a dataset derived from the 2011–2014 National Health and Nutrition Examination Survey (NHANES). A total of 806 adults (≥ 60 years) were included who underwent comprehensive cognitive testing and plasma fatty acid measurements. Multivariable linear regression, restricted cubic spline (RCS), and interaction analyses were used to assess associations between VLSFAs and cognitive function. Partial Spearman’ s correlation analysis was used to examine the correlations between VLSFAs and palmitic acid (16:0), high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, total cholesterol, triglycerides, systemic inflammatory markers, and dietary nutrients.ResultsMultivariable linear regression analysis, adjusting for sociodemographic, clinical conditions, and lifestyle factors, showed that 22:0 and 24:0 levels were positively associated with better global cognitive function (β = 0.37, 95% confidence interval [CI] = 0.01, 0.73; β = 0.73, 95% CI = 0.29, 1.2, respectively) as well as better CEARD-DR Z-score (β = 0.82, 95% CI = 0.36, 1.3 and β = 1.2, 95% CI = 0.63, 1.8, respectively). RCS analysis showed linear associations between higher 22:0 and 24:0 levels and better cognitive performance in both global cognitive function and CERAD-DR tests.ConclusionsThe study suggests that higher levels of 22:0 and 24:0 are associated with better global cognitive function in older adults. 22:0 and 24:0 may be important biomarkers for recognizing cognitive impairment, and supplementation with specific VLSFAs (22:0 and 24:0) may be an important intervention to improve cognitive function. Further studies are needed to elucidate the underlying biological mechanisms between VLSFAs and cognitive function.

Depressive symptoms and cognitive decline in older adults.

Few studies have examined the impact of late-life depression trajectories on specific domains of cognitive function. This study aims to delineate how different depressive symptom trajectories specifically affect cognitive function in older adults. Prospective longitudinal cohort study. Australia and the United States of America. In total, 11,035 community-dwelling older adults with a mean age of 75 years. Depressive trajectories were modelled from depressive symptoms according to annual Centre for Epidemiological Studies Depression Scale 10 (CES-D-10) surveys. Four trajectories of depressive symptoms were identified: low ("nondepressed"), consistently mild ("subthreshold depression"), consistently moderate ("persistent depression"), and initially low but increasing ("emerging depression"). Global cognition (Modified Mini-Mental State Examination [3MS]), verbal fluency (Controlled Oral Word Association Test [COWAT]), processing speed (Symbol Digit Modalities Test [SDMT]), episodic memory (Hopkins Verbal Learning Test - Revised [HVLT-R]), and a composite z-score were assessed over a subsequent median 2 years. Subthreshold depression predicted impaired performance on the SDMT (Cohen's d -0.04) and composite score (-0.03); emerging depression predicted impaired performance on the SDMT (-0.13), HVLT-R (-0.09), 3 MS (-0.08) and composite score (-0.09); and persistent depression predicted impaired performance on the SDMT (-0.08), 3 MS (-0.11), and composite score (-0.09). Depressive symptoms are associated with later impaired processing speed. These effects are small. Diverse depression trajectories have different impacts on cognitive function.

Perceived Stress, Blood Biomarkers, and Cognitive Functioning in Older Adults.

There is a substantial gap in knowledge regarding how perceived stress may influence the relationship between serum-measured biomarkers for Alzheimer's disease and cognitive decline. This study consists of 1,118 older adult participants from the Chicago Health and Aging Project (CHAP) (60% Black participants and 63% female participants). Linear mixed effects regression models were conducted to examine the role of perceived stress in the association between three blood biomarkers: total tau (t-tau), glial fibrillary acid protein (GFAP), and neurofilament light chain (NfL) on global cognitive decline. Stratified analysis by stress level was also conducted to evaluate the associations between each blood biomarker and baseline cognitive function and decline. All models adjusted for age, race, sex, education, time, and their interactions with time. The interaction of stress, NfL concentration, and time was statistically significant on global cognition (β = -0.064 (SE = 0.028), p-value = 0.023) and on episodic memory (β = -0.097 (SE = 0.036), p-value = 0.007). Greater stress level worsens the association between high NfL concentration and cognitive decline. Stress management interventions may be helpful to reduce rate of cognitive decline in individuals with high concentrations of NfL.

Resistance training's impact on blood biomarkers and cognitive function in older adults with low and high risk of mild cognitive impairment: a randomized controlled trial

BackgroundThe aging brain exhibits a neuroinflammatory state, driven partly by peripheral pro-inflammatory stimuli, that accelerates cognitive deterioration. A growing body of evidence clearly indicates that physical exercise partly alleviates neuroinflammation and positively affects the aging process and cognition. In this randomized controlled trial, we aimed to observe the effect of 12 weeks of resistance training (RT) on peripheral biomarker levels, cognitive function changes and their interrelationship, and explore differences in those exercise-induced changes in older adults with high risk of mild cognitive impairment (MCI) compared to older adults with low risk of MCI.MethodsFifty-two participants (aged 60–85 years old, 28 female) were randomly allocated to a 12 week lower limb RT program consisting of two training sessions per week or waiting list control group. The Montreal Cognitive Assessment (MoCA) was used to stratify participants screened as high (< 26/30) or low risk (≥ 26/30) of MCI. We assessed serum Interleukin 6 (IL-6), Insulin-like Growth Factor-1 (IGF-1), and Kynurenine (KYN) levels. Cognitive measurement consisted of and four subtests of Automated Neuropsychological Assessment Metrics (ANAM), the two-choice reaction time, go/no-go, mathematical processing, and memory search test.ResultsTwelve weeks of RT improved Go/No-go test results in older adults with high MCI risk. RT did not significantly affect blood biomarkers. However, IGF-1 level increases were associated with improvements in response time on the mathematical processing test in the exercise group, and IL-6 level increases were associated with improvements in response time on the memory search test in the total group of participants. Finally, KYN levels significantly differed between older adults with low and high MCI risk but no significant associations with performance were found.ConclusionOur study results suggest a different effect of RT on inhibitory control between older adults with low compared to high MCI risk. IGF-1 may play a role in the mechanism behind the cognitive benefit of RT and KYN may be a surrogate biomarker for neurodegeneration and cognitive decline.