Physical activity and risk of cognitive impairment and dementia in elderly persons

Association between sedentary behavior and the risk of dementia: a systematic review and meta-analysis

An increasing number of original studies suggest that sedentary behavior is associated with the risk of dementia, but the results remain inconsistent and inconclusive. In this meta-analysis, we analyzed available observational epidemiological evidence to identify the association between sedentary behavior and the risk of dementia. We searched PubMed and Embase from their inception to March 2019 to identify observational studies examining the association between sedentary behavior and risk of dementia. Two authors independently extracted data and assessed study quality using predefined criteria. The Q statistics and I² methods were used to test for heterogeneity. The publication bias of the included studies was also estimated using Begg's and Egger's tests. We identified 18 relevant cohort studies involving 250,063 participants and 2269 patients with dementia. Pooled result showed that sedentary behavior was significantly associated with increased risk of dementia (RR = 1.30; 95% CI: 1.12-1.51). In addition, subgroup analyses by state, and controlling for the concomitant effects of age, sex, education were conducted for the increase of dementia risk, relating to sedentary, respectively. In general, these subgroup analyses showed no statistically significant differences. The results of our meta-analysis suggested that sedentary behavior was independently associated with a significantly increased risk of dementia, which might have important implications in conducting etiological studies for dementia and developing strategies for dementia prevention.

Drum Communication Program Intervention in Older Adults With Cognitive Impairment and Dementia at Nursing Home: Preliminary Evidence From Pilot Randomized Controlled Trial

Introduction: Inactivity and consequent deterioration of cognitive and physical function is a major concern among older adults with the limited walking ability and need a high level of care in nursing homes. We aimed to test whether a drumming communication program (DCP) that uses the rhythmic response function of the elderly with cognitive impairment, dementia, and other debilitating disorders would improve their cognitive and physical function. Methods: We conducted a Randomized Controlled Trial (RCT) to investigate the effects of the DCP in 46 nursing home residents who needed high levels of nursing care. The participants were randomly assigned to an intervention and control group. The intervention group attended 30 min of the DCP thrice a week for 3 months. Cognitive function was measured using the Mini-Mental State Examination-Japanese (MMSE-J) and Frontal Assessment Battery (FAB). Physical function was measured using grip strength and active upper limb range of motion with the dominant hand. Body composition was measured using bioelectrical impedance analysis (BIA). These measures were analyzed before and after the DCP intervention period, and data for the two groups were compared thereafter. Results: Initially, the participants had low scores on the MMSE-J, and 84.78% of them used wheelchairs. Following the DCP intervention, the MMSE-J and FAB scores of the DCP group improved significantly. In terms of motor function, the active range of motion of the wrist palmar and the shoulder flexion improved in the intervention group. Regarding body composition, the skeletal muscle mass index, total body protein, and the dominant hand muscle mass that was adding physical load decreased. Conclusions: The DCP provided the participants with an opportunity to engage in continued exercise for 3 months. The intervention group exhibited improved cognitive function and upper limb motion range, and changes in body composition. The results suggest that DCP can be used as an intervention method to promote exercise and improve various health and cognitive functions. Trial Registration: This trial was registered at the University Hospital Medical Information Network Clinical Trial Registry (UMIN000024714) on 4 November 2016. The URL is available at https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000028399.

The role of CREB and BDNF in neurobiology and treatment of Alzheimer's disease

Alzheimer's disease (AD) is the most common form of dementia worldwide. β-amyloid peptide (Aβ) is currently assumed to be the main cause of synaptic dysfunction and cognitive impairments in AD, but the molecular signaling pathways underlying its neurotoxic consequences have not yet been completely explored. Additional investigations regarding these pathways will contribute to development of new therapeutic targets. In context, developing evidence suggest that Aβ decreases brain-derived neurotrophic factor (BDNF) mostly by lowering phosphorylated cyclic adenosine monophosphate (cAMP) response element binding protein (CREB) protein. In fact, it has been observed that brain or serum levels of BDNF appear to be beneficial markers for cognitive condition. In addition, the participation of transcription mediated by CREB has been widely analyzed in the memory process and AD development. Designing pharmacologic or genetic therapeutic approaches based on the targeting of CREB-BDNF signaling could be a promising treatment potential for AD. In this review, we summarize data demonstrating the role of CREB-BDNF signaling pathway in cognitive status and mediation of Aβ toxicity in AD. Finally, we also focus on the developing intervention methods for improvement of cognitive decline in AD based on targeting of CREB-BDNF pathway.

Physical activity and cognitive function: between-person and within-person associations and moderators

In the present study, we decomposed between- and within-person effects and examined moderators of the longitudinal physical activity-cognition association. Participants (N = 1722) were drawn from the Betula study and we included four waves of data across 15 years. Bayesian multilevel modeling showed that self-reported physical activity did not predict changes in cognitive function. Physical activity positively predicted cognitive performance at baseline, and the relations were stronger for more active (compared to less active) older adults. Physical activity had a positive within-person effect on cognitive function. The within-person effect of physical activity on episodic memory recall was stronger for participants who on average engaged in less physical activity. The within-person effect on verbal fluency was stronger for participants with more education. Our results suggest that preserving cognitive functioning in old age might be more a matter of what you do in old age than reflecting what you did earlier in life.

Does Anxiety Increase the Risk of All-Cause Dementia? An Updated Meta-Analysis of Prospective Cohort Studies

Background: Anxiety has been suggested as a potentially modifiable risk factor for dementia, but results are still controversial. Our main objectives are to develop an updated meta-analysis of prospective population-based studies on the relationship between anxiety and risk of dementia, and to estimate the population fraction of dementia attributable to anxiety (PAF). Methods: We searched for cohort studies listed on PubMed or Web of Science from January 2018 to January 2020 that reported risk estimates for the association between anxiety and incident dementia. These were added to cohort studies published before January 2018 that were used in a previously published meta-analysis. Fully adjusted RRs were pooled using random effects models. We estimated the proportion of incident dementia attributable to anxiety by using PAF. Results: The meta-analysis included nine prospective cohorts from eight studies, representing 29,608 participants. The overall relative risk (RR) of dementia was 1.24 (95% CI: 1.06–1.46) and the PAF of dementia due to anxiety was 3.9%. Conclusions: Anxiety is significantly associated with an increased risk of all-cause dementia. The treatment or prevention of anxiety might help to reduce dementia incidence rates, but more research is needed to clarify whether anxiety is a cause of dementia rather than a prodrome.

Understanding Health Deterioration and the Dynamic Relationship between Physical Ability and Cognition among a Cohort of Danish Nonagenarians

This study aims to determine how demographics, socioeconomic characteristics, and lifestyle affect physical and cognitive health transitions among nonagenarians, whether these transitions follow the same patterns, and how each dimension affects the transitions of the other. We applied a multistate model for panel data to 2262 individuals over a 2-year follow-up period from the 1905 Danish Cohort survey. Within two years from baseline, the transition probability from good to bad physical health-ability to stand up from a chair-was higher than dying directly (29% vs. 25%), while this was not observed for cognition (24% vs. 27%) evaluated with Mini-Mental State Examination-a score lower than 24 indicates poor cognitive health. Probability of dying either from bad physical or cognitive health condition was 50%. Health transitions were associated with sex, education, living alone, body mass index, and physical activity. Physical and cognitive indicators were associated with deterioration of cognitive and physical status, respectively, and with survivorship from a bad health condition. We conclude that physical and cognitive health deteriorated differently among nonagenarians, even if they were related to similar sociodemographic and lifestyle characteristics and resulted dynamically related with each other.

The Relationship between Chronotype, Physical Activity and the Estimated Risk of Dementia in Community-Dwelling Older Adults

Our study examined the association between chronotype, daily physical activity, and the estimated risk of dementia in 170 community-dwelling older adults. Chronotype was assessed with the Horne-Östberg Morningness-Eveningness Questionnaire (MEQ). Daily physical activity (of over 3 METs) was measured with a tri-axial accelerometer. The Korean version of the Mini-Mental State Examination (K-MMSE) was used to measure the estimated risk of dementia. The evening chronotype, low daily physical activity, and dementia were positively associated with each other. The participants with low physical activity alongside evening preference had 3.05 to 3.67 times higher estimated risk of developing dementia, and participants with low physical activity and morning preference had 1.95 to 2.26 times higher estimated risk than those with high physical activity and morning preference. Our study design does not infer causation. Nevertheless, our findings suggest that chronotype and daily physical activity are predictors of the risk of having dementia in older adults aged 70 years and above.

What works and what does not work in Alzheimer's disease? From interventions on risk factors to anti-amyloid trials

Alzheimer's disease (AD) is a progressive neurodegenerative disorder with no approved disease-modifying therapy (DMT). In this review, we summarize the various past approaches taken in an attempt to find treatments capable of altering the long-term course for individuals with AD, including: translating epidemiological observations into potential treatment options; seeking a single-treatment approach across the continuum of AD severity; utilizing biomarkers for assessing target engagement; using biomarkers as early surrogates of clinical efficacy; and enriching study populations to demonstrate adequate placebo decline during the limited duration of clinical trials. Although targeting the amyloid-β (Aβ) pathway has been central to the search for an effective DMT, to date, trials of anti-Aβ monoclonal antibodies have failed to consistently demonstrate significant clinical efficacy. Key learnings from these anti-Aβ trials, as well as the trials that came before them, have shifted the focus within clinical development programs to identifying target populations thought most likely to benefit from treatments (i.e., individuals at an earlier stage of disease). Other learnings include strategies to increase the likelihood of showing measurable improvements within the clinical trial setting by better predicting decline in placebo participants, as well as developing measures to quantify the needed treatment exposure (e.g., higher doses). Given the complexity associated with AD pathology and progression, treatments targeting non-amyloid AD pathologies in combination with anti-amyloid therapies may offer an alternative for the successful development of DMTs.

Risk of dementia in prostate cancer survivors: A nationwide cohort study in Korea

OBJECTIVES

To investigate the effects of prostate cancer (PC) and various treatment modalities for PC, specifically androgen deprivation therapy (ADT), on the risk of dementia and dementia subtypes in PC survivors.

MATERIAL AND METHODS

A total of 51,252 patients newly diagnosed with PC from 2007 to 2013, who had no prior diagnosis of cancer or dementia, were included and matched with 209,659 non-cancer control. The screening subset was comprised of subjects who participated in a health screening program. We used Cox proportional hazards model to estimate the relative risk of dementia and dementia subtypes according to the primary treatment for the PC.

RESULTS

Compared to non-PC matched controls, PC survivors showed slightly higher risk for dementia and Alzheimer disease (AD) only in the screening cohort. While PC survivors who underwent ADT were higher risk for dementia and AD, patients who underwent surgery were lower risk for dementia and AD, compared to the non-cancer population. Compared to surgery, ADT, surgery + ADT, and active surveillance/watchful waiting showed a significantly elevated risk for dementia.

CONCLUSION

PC survivors had slightly higher risk for dementia compared to non-PC controls, which might be related to the screening effects of PC. The risk for dementia was most prominent among PC patients who underwent ADT, followed by patients who underwent AS/WW, and those who underwent surgery + ADT. This finding suggests that individualized ADT strategies that consider the survival benefit and underlying dementia risk in PC survivors are necessary.

Get Moving! Increases in Physical Activity Are Associated With Increasing Functional Connectivity Trajectories in Typically Aging Adults

Background: Physical activity closely relates to cognition and brain structure as we age. However, the neural mechanisms underlying this relationship in humans remain less clear. Functional connectivity (FC), measured by task-free functional MRI (tf-fMRI) is a dynamic marker of network activity and may be a sensitive indicator of the brain's response to exercise over time. We aimed to test the longitudinal relationship between physical activity and FC trajectories in functionally normal older adults. Methods: Two hundred and twelve functionally normal, longitudinally-followed older adults completed the Physical Activity Scale for the Elderly (PASE) and tf-fMRI scans at each visit [mean = 1.5 visits (range:1-3)]. We studied FC of the default mode network (DMN), frontal-parietal (FP), subcortical networks (SubCort), and frontal-subcortical inter-network connectivity (FS), given that previous studies implicate these regions in age-related changes. Linear mixed-effects models examined the relationship between within-person changes in PASE and FC (in SD units), covarying for age, sex, education and systemic cardiovascular risk factors (heart rate, BMI and systolic blood pressure). We additionally examined models covarying for DTI fractional anisotropy (FA) and mean diffusivity (MD) of tracts underlying networks of interest, as a marker of cerebrovascular disease. Furthermore, we examined the longitudinal relationship between PASE and neuropsychological trajectories. Results: In our first model, within-subject increases in physical activity tracked with increasing SubCort (β = 0.33, p = 0.007) and FS inter-network (β = 0.27, p = 0.03) synchrony, while between-subject parameters did not reach significance (β = -0.042 to -0.07, ps > 0.37). No significant longitudinal associations were observed between PASE and DMN (β = -0.02 p = 0.89) or FP networks (β = 0.15, p = 0.23). Adjusting for markers of cerebrovascular health (FA/MD) did not change estimated effects (SubCort: β = 0.31, p = 0.01, FS inter-network: β = 0.28, p = 0.03). Associations between changes in physical activity and neuropsychological trajectories were small (β = -0.14 to 0.002) and did not reach statistical significance (p-values >0.42). Conclusions: Our findings suggest that changes in exercise over time are specifically associated with frontal-subcortical processes in older adults. This relationship appears to be independent of cardio- or cerebrovascular disease, possibly driven by a more direct neural response to exercise.

Harnessing digital health to objectively assess cognitive impairment in people undergoing hemodialysis process: The Impact of cognitive impairment on mobility performance measured by wearables

Cognitive impairment is prevalent but still poorly diagnosed in hemodialysis adults, mainly because of the impracticality of current tools. This study examined whether remotely monitoring mobility performance can help identifying digital measures of cognitive impairment in hemodialysis patients. Sixty-nine diabetes mellitus hemodialysis patients (age = 64.1±8.1years, body mass index = 31.7±7.6kg/m2) were recruited. According to the Mini-Mental State Exam, 44 (64%) were determined as cognitive-intact, and 25 (36%) as cognitive-impaired. Mobility performance, including cumulated posture duration (sitting, lying, standing, and walking), daily walking performance (step and unbroken walking bout), as well as postural-transition (daily number and average duration), were measured using a validated pendant-sensor for a continuous period of 24-hour during a non-dialysis day. Motor capacity was quantified by assessing standing balance and gait performance under single-task and dual-task conditions. No between-group difference was observed for the motor capacity. However, the mobility performance was different between groups. The cognitive-impaired group spent significantly higher percentage of time in sitting and lying (Cohens effect size d = 0.78, p = 0.005) but took significantly less daily steps (d = 0.69, p = 0.015) than the cognitive-intact group. The largest effect of reduction in number of postural-transition was observed in walk-to-sit transition (d = 0.65, p = 0.020). Regression models based on demographics, addition of daily walking performance, and addition of other mobility performance metrics, led to area-under-curves of 0.76, 0.78, and 0.93, respectively, for discriminating cognitive-impaired cases. This study suggests that mobility performance metrics could be served as potential digital biomarkers of cognitive impairment among hemodialysis patients. It also highlights the additional value of measuring cumulated posture duration and postural-transition to improve the detection of cognitive impairment. Future studies need to examine potential benefits of mobility performance metrics for early diagnosis of cognitive impairment/dementia and timely intervention.

Physical activity types and risk of dementia in community-dwelling older people: the Three-City cohort

BACKGROUND

Physical activity may decrease the risk of dementia; however, previous cohort studies seldom investigated the different types of physical activity and household activities. Our objective was to analyze the links between two physical activity types and dementia in older people.

METHODS

The study used data from the prospective observational Three-city cohort and included 1550 community-dwelling individuals aged 72 to 87 without dementia at baseline. Physical activity was assessed with the Voorrips questionnaire. Two sub-scores were calculated to assess household/transportation activities and leisure/sport activities. Restricted cubic spline and proportional hazard Cox models were used to estimate the non-linear exposure-response curve for the dementia risk and the appropriate activity level thresholds. Models were adjusted for possible confounders, including socio-demographic variables, comorbidities, depressive symptoms and APOE genotype.

RESULTS

The median age was 80 years, and 63.6% of participants were women. After a median follow-up of 4.6 years, dementia was diagnosed in 117 participants (7.6%). An inverse J-shaped association was found between household/transportation physical activity sub-score and dementia risk, which means that the risk is lowest for the moderately high values and then re-increases slightly for the highest values. The results remained significant when this sub-score was categorized in three classes (low, moderate, and high), with hazard ratios (95% confidence interval) of 0.55 (0.35-0.87) and 0.62 (0.38-1.01) for moderate and high activity levels, respectively. No significant effect was found for leisure/sport activities.

CONCLUSIONS

The 5-year risk of dementia was significantly and negatively associated with the household/transportation activity level, but not with the leisure and sport activity sub-score. This highlights the importance of considering all physical activity types in 72 years or older people.

Self-reported Lifestyle Activities in Relation to Longitudinal Cognitive Trajectories

BACKGROUND

Few studies have examined the relationship between lifestyle activity engagement and cognitive trajectories among individuals who were cognitively normal at baseline.

OBJECTIVE

To examine the relationship of current engagement in lifestyle activities to previous cognitive performance among individuals who were cognitively normal at baseline, and whether this relationship differed for individuals who subsequently developed mild cognitive impairment (MCI), or by APOE-4 genotype, age, and level of cognitive reserve.

METHODS

Participants (N=189) were primarily middle-aged (M=56.6 y) at baseline and have been prospectively followed with annual assessments (M follow-up=14.3 y). Engagement in physical, cognitive, and social activities was measured by the CHAMPS activity questionnaire. Longitudinal cognitive performance was measured by a global composite score.

RESULTS

Among individuals who progressed to MCI (n=27), higher lifestyle activity engagement was associated with less decline in prior cognitive performance. In contrast, among individuals who remained cognitively normal, lifestyle activity engagement was not associated with prior cognitive trajectories. These effects were largely independent of APOE-4 genotype, age, and cognitive reserve.

CONCLUSIONS

Greater engagement in lifestyle activities may modify the rate of cognitive decline among those who develop symptoms of MCI, but these findings need to be confirmed in prospective studies.

Relationship Between Exercise and Alzheimer's Disease: A Narrative Literature Review

This narrative review aimed to summarize evidence regarding the responses to exercise among patients with preclinical Alzheimer’s disease (AD) and the effectiveness of long-term exercise interventions in improving cognitive function and neuropsychiatric symptoms. We performed a narrative review of existing literature on the effectiveness of long-term exercise interventions in improving cognitive function and neuropsychiatric symptoms in patients with AD. Patients with AD who presented with long-term exercise interventions appeared to have improved blood flow, increased hippocampal volume, and improved neurogenesis. Most prospective studies have proven that physical inactivity is one of the most common preventable risk factors for developing AD and that higher physical activity levels are associated with a reduced risk of AD development. Physical exercise seems to be effective in improving several neuropsychiatric symptoms of AD, notably cognitive function. Compared with medications, exercise has been shown to have fewer side effects and better adherence.

Unsupervised low-intensity home exercises as an effective intervention for improving physical activity and physical capacity in the community-dwelling elderly

[Purpose] The purpose of this study was to examine the effectiveness of unsupervised low-intensity home exercises in improving physical activity and physical capacity for daily activities among the community-dwelling elderly. [Participants and Methods] We included 24 female older participants and divided them into two groups: 14 in the resistance training group and 10 in the fast walking group. The resistance training group performed shoulder joint flexion and abduction exercises using a resistance tube twice daily (in the morning and afternoon). Participants in the fast walking group walked fast for 3,000 steps once daily. Both groups continued the exercise intervention for 6 months. We measured the forced vital capacity, respiratory muscle strength, physical activity, walking distance in the 6-min walk test, grip strength, and knee extension strength before and after the intervention. [Results] The forced vital capacity significantly increased in the resistance training group, whereas the moderate-intensity physical activity time significantly increased in both groups and the vigorous-intensity physical activity time increased in the fast walking group only. We observed no intergroup differences in respiratory muscle strength, 6-min walking distance, grip strength, or knee extension strength. [Conclusion] The results of this study suggest that low-intensity home exercises can improve pulmonary function and physical activity and should be recommended for promoting health in the community-dwelling elderly.

The Contribution of Functional Magnetic Resonance Imaging to the Understanding of the Effects of Acute Physical Exercise on Cognition

The fact that a single bout of acute physical exercise has a positive impact on cognition is well-established in the literature, but the neural correlates that underlie these cognitive improvements are not well understood. Here, the use of neuroimaging techniques, such as functional magnetic resonance imaging (fMRI), offers great potential, which is just starting to be recognized. This review aims at providing an overview of those studies that used fMRI to investigate the effects of acute physical exercises on cerebral hemodynamics and cognition. To this end, a systematic literature survey was conducted by two independent reviewers across five electronic databases. The search returned 668 studies, of which 14 studies met the inclusion criteria and were analyzed in this systematic review. Although the findings of the reviewed studies suggest that acute physical exercise (e.g., cycling) leads to profound changes in functional brain activation, the small number of available studies and the great variability in the study protocols limits the conclusions that can be drawn with certainty. In order to overcome these limitations, new, more well-designed trials are needed that (i) use a more rigorous study design, (ii) apply more sophisticated filter methods in fMRI data analysis, (iii) describe the applied processing steps of fMRI data analysis in more detail, and (iv) provide a more precise exercise prescription.

Does lifestyle matter? Individual lifestyle factors and their additive effects associated with cognitive function in older men and women

Objectives: This study investigated the association between healthy lifestyle comprised of multiple domains, gender, and cognitive function in older Chinese people in Hong Kong.Methods: We conducted a cross-sectional analysis with data from 1,831 community-dwellers aged 65 years and above. Participants' basic demographics, comorbidity, and six lifestyle factors: diet; smoking; alcohol drinking; and physical, mental, and social activities were surveyed. Cognitive function was assessed using the Cantonese Chinese Montreal Cognitive Assessment (CC-MoCA). Linear regressions were performed to examine the associations between lifestyle, gender, and cognitive performance.Results: There were gender differences in lifestyle: men smoked (χ²(1) = 159.4) and drank more (χ²(1) = 85.9) and were more active in mentally stimulating activities (χ²(1) = 14.3, all p<.001); while women were more socially active (χ²(1) = 28.0). Age, gender and education explained the greatest variance in cognition (R²=.32). Being active/healthy in more domains further contributed to better cognitive function, although the effect was small (ΔR²=0.03 in women; ΔR²=0.01 in men, both p<.05). Among the lifestyle domains, physical activity showed the strongest effects on cognitive function (ΔR²=0.004 in men and ΔR²=0.02 in women, both p<.05).Conclusions: Naturalistically, a physically active lifestyle and being active/healthy in more domains is associated with better cognitive function in older people after controlling for non-modifiable and early-life factors. The effects are however small. There are gender differences in lifestyle and the impact of lifestyle on cognitive function. Preventive strategies targeting lifestyle domains for cognitive health in older people may consider these naturalistic associations.

Born to Protect: Leveraging BDNF Against Cognitive Deficit in Alzheimer's Disease

Alzheimer's disease is a chronic neurodegenerative devastating disorder affecting a high percentage of the population over 65 years of age and causing a relevant emotional, social, and economic burden. Clinically, it is characterized by a prominent cognitive deficit associated with language and behavioral impairments. The molecular pathogenesis of Alzheimer's disease is multifaceted and involves changes in neurotransmitter levels together with alterations of inflammatory, oxidative, hormonal, and synaptic pathways, which may represent a drug target for both prevention and treatment; however, an effective treatment for Alzheimer's disease still represents an unmet goal. As neurotrophic factors participate in the modulation of the above-mentioned pathways, they have been highlighted as critical contributors of Alzheimer's disease etiology, whose modulation might be beneficial for Alzheimer's disease. We focused on the neurotrophin brain-derived neurotrophic factor, providing several lines of evidence pointing to brain-derived neurotrophic factor as a plausible endophenotype of cognitive deficits in Alzheimer's disease, illustrating some of the most recent possibilities to modulate the expression of this neurotrophin in the brain in an attempt to ameliorate cognition and delay the progression of Alzheimer's disease. This review shows that otherwise disparate pharmacologic or non-pharmacologic approaches converge on brain-derived neurotrophic factor, providing a means whereby apparently unrelated medical approaches may nevertheless produce similar synaptic and cognitive outcomes in Alzheimer's disease pathogenesis, suggesting that brain-derived neurotrophic factor-based synaptic repair may represent a modifying strategy to ameliorate cognition in Alzheimer's disease.

Mechanistic models to guide redox investigations and interventions in musculoskeletal ageing

Age is the greatest risk factor for the major chronic musculoskeletal disorders, osteoarthritis, osteoporosis and age-related loss of skeletal muscle mass and function (sarcopenia). Dramatic advances in understanding of the fundamental mechanisms underlying the ageing process are being exploited to understand the causes of these age-related disorders and identify approaches to prevent or treat these disorders. This review will focus on one of these fundamental mechanisms, redox regulation, and the role of redox changes in age-related loss of skeletal muscle mass and function (sarcopenia). Key to understanding the role of such pathways has been the development and study of experimental models of musculoskeletal ageing that are designed to examine the effect of modification of ROS regulatory enzymes. These have primarily involved genetic deletion of regulatory enzymes for ROS in mice. Many of the models studied show increased oxidative damage in tissues, but no clear relationship with skeletal muscle aging has been seen The exception to this has been mice with disruption of the superoxide dismutases and, in particular, deletion of Cu,ZnSOD (SOD1) localised in the cytosol and mitochondrial intermembrane space. Studies of tissue specific models lacking SOD1 have highlighted the potential role that disrupted redox pathways can play in muscle loss and weakness and have demonstrated the need to study both motor neurons and muscle to understand age-related loss of skeletal muscle. The complex interplay that has been identified between changes in redox homeostasis in the motor neuron and skeletal muscle and their role in premature loss of muscle mass and function illustrates the utility of modifiable models to establish key pathways that may contribute to age-related changes and identify potential logical approaches to intervention.

Exercise Training Results in Lower Amyloid Plaque Load and Greater Cognitive Function in an Intensity Dependent Manner in the Tg2576 Mouse Model of Alzheimer's Disease

Three months of exercise training (ET) decreases soluble Aβ₄₀ and Aβ₄₂ levels in an intensity dependent manner early in life in Tg2576 mice (Moore et al., 2016). Here, we examined the effects of 12 months of low- and high- intensity exercise training on cognitive function and amyloid plaque load in the cortex and hippocampus of 15-month-old Tg2576 mice. Low- (LOW) and high- (HI) intensity ET animals ran at speeds of 15 m/min on a level treadmill and 32 m/min at a 10% grade, respectively, for 60 min/day, five days/week, from 3 to 15 months of age. Sedentary mice (SED) were placed on a level, non-moving, treadmill for the same duration. ET mice demonstrated a significantly lower amyloid plaque load in the cortex and hippocampus that was intensity dependent. Improvement in cognitive function, assessed by Morris Water Maze and Novel Object Recognition tests, was greater in the HI group compared to the LOW and SED groups. LOW mice performed better in the initial latency to the platform location during the probe trial of the Morris Water Maze (MWM) test than SED, but not in any other aspect of MWM or the Novel Object Recognition test. The results of this study indicate that exercise training decreases amyloid plaque load in an intensity dependent manner and that high-intensity exercise training improves cognitive function relative to SED mice, but the intensity of the LOW group was below the threshold to demonstrate robust improvement in cognitive function in Tg2576 mice.

Trends and risk factors of elderly-onset Crohn’s disease: A nationwide cohort study

BACKGROUND

The incidence of inflammatory bowel disease (IBD) is increasing in Asia. Numerous risk factors associated with IBD development have been investigated.

AIM

To investigate trends and environmental risk factors of Crohn’s disease (CD) diagnosed in persons aged ≥ 40 years in South Korea.

METHODS

Using the National Health Insurance Service database, a total of 14060821 persons aged > 40 years who underwent national health screening in 2009 were followed up until December 2017. Patients with newly diagnosed CD were enrolled and compared with non-CD cohort. CD was identified according to the International Classification of Diseases 10th revision and the rare/intractable disease registration program codes from the National Health Insurance Service database. The mean follow-up periods was 7.39 years. Age, sex, diabetes, hypertension, smoking, alcohol consumption, regular exercise, body mass index, anemia, chronic kidney disease (CKD) and dyslipidemia were adjusted for in the multivariate analysis model.

RESULTS

During the follow-up, 1337 (1.33/100000) patients developed CD. Men in the middle-aged group (40-64 years) had a higher risk than women [adjusted hazard ratio (aHR) 1.46, 95% confidence interval (CI): 1.29-1.66]; however, this difference tended to disappear as the age of onset increases. In the middle-aged group, patients with a history of smoking [aHR 1.46, 95%CI: 1.19-1.79) and anemia (aHR 1.85, 95%CI: 1.55-2.20) had a significantly higher CD risk. In the elderly group (age, ≥ 65 years), ex-smoking and anemia also increased the CD risk (aHR 1.68, 95%CI: 1.22-2.30) and 1.84 (95%CI: 1.47-2.30, respectively). Especially in the middle-aged group, those with CKD had a statistically elevated CD risk (aHR 1.37, 95%CI: 1.05-1.79). Alcohol consumption and higher body mass index showed negative association trend with CD incidence in both of the age groups. [Middle-aged: aHR 0.77 (95%CI: 0.66-0.89) and aHR 0.73 (95%CI: 0.63-0.84), respectively] [Elderly-group: aHR 0.57 (95%CI: 0.42-0.78) and aHR 0.84 (95%CI 0.67-1.04), respectively]. For regular physical activity and dyslipidemia, negative correlation between CD incidences was proved only in the middle-aged group [aHR 0.88 (95%CI: 0.77-0.89) and aHR 0.81 (95%CI: 0.68-0.96), respectively].

CONCLUSION

History of cigarette smoking, anemia, underweight and CKD are possible risk factors for CD in Asians aged > 40 years.

Road proximity, air pollution, noise, green space and neurologic disease incidence: a population-based cohort study

BACKGROUND

Emerging evidence links road proximity and air pollution with cognitive impairment. Joint effects of noise and greenness have not been evaluated. We investigated associations between road proximity and exposures to air pollution, and joint effects of noise and greenness, on non-Alzheimer's dementia, Parkinson's and Alzheimer's disease and multiple sclerosis within a population-based cohort.

METHODS

We assembled administrative health database cohorts of 45-84 year old residents (N ~ 678,000) of Metro Vancouver, Canada. Cox proportional hazards models were built to assess associations between exposures and non-Alzheimer's dementia and Parkinson's disease. Given reduced case numbers, associations with Alzheimer's disease and multiple sclerosis were evaluated in nested case-control analyses by conditional logistic regression.

RESULTS

Road proximity was associated with all outcomes (e.g. non-Alzheimer's dementia hazard ratio: 1.14, [95% confidence interval: 1.07-1.20], for living < 50 m from a major road or < 150 m from a highway). Air pollutants were associated with incidence of Parkinson's disease and non-Alzheimer's dementia (e.g. Parkinson's disease hazard ratios of 1.09 [1.02-1.16], 1.03 [0.97-1.08], 1.12 [1.05-1.20] per interquartile increase in fine particulate matter, Black Carbon, and nitrogen dioxide) but not Alzheimer's disease or multiple sclerosis. Noise was not associated with any outcomes while associations with greenness suggested protective effects for Parkinson's disease and non-Alzheimer's dementia.

CONCLUSIONS

Road proximity was associated with incidence of non-Alzheimer's dementia, Parkinson's disease, Alzheimer's disease and multiple sclerosis. This association may be partially mediated by air pollution, whereas noise exposure did not affect associations. There was some evidence of protective effects of greenness.

Using Physical Activity to Enhance Health Outcomes Across the Life Span

Physical activity has been widely recognized as one of the primary determinants that proliferates positive psychophysiological health in individuals. Despite the numerous benefits of engaging in physical activity, a majority of the global population continues to be physically inactive or sedentary. The aim of this brief commentary is to capture the benefits of engaging in regular physical activity across the life span. In particular, this paper will highlight the benefits of engaging in regular physical activity with respect to age, gender, atypical populations, and lifestyle. Future research and recommendations have also been addressed.

Impact of Zumba on Cognition and Quality of Life is Independent of APOE4 Carrier Status in Cognitively Unimpaired Older Women: A 6-Month Randomized Controlled Pilot Study

OBJECTIVE

To investigate the association of a 6-month Zumba intervention with cognition and quality of life among older cognitively unimpaired apolipoprotein ∊4 (APOE4) carrier and noncarrier women.

METHODS

Fifty-three women were randomly assigned to either twice-weekly Zumba group classes or maintenance of habitual exercise (control group) for 6 months. At baseline, 3, and 6 months, all participants underwent neuropsychological, physical activity, and quality-of-life assessments.

RESULTS

Overall, neuropsychological test scores and level of physical activity did not differ between intervention and control groups at any time. However, compared to the control group, quality of life was higher at 3 months, and visuospatial working memory and response inhibition improved more in the intervention group by 6 months. Apolipoprotein ∊4 status did not affect the results.

DISCUSSION

Zumba may strengthen performance on visuospatial working memory among cognitively unimpaired older women but this needs to be tested in a larger clinical trial.

ABCA7 Genotype Moderates the Effect of Aerobic Exercise Intervention on Generalization of Prior Learning in Healthy Older African Americans

African Americans are at elevated risk for age-related cognitive decline, with double the prevalence of Alzheimer's disease (AD) compared to Caucasians Americans. Various behavioral, biological, and lifestyle factors may underlie this health disparity, but little is known about the relative importance and interactions among these different risk factors in African Americans. While the neuroprotective effects of aerobic exercise on biomarkers are well established, few studies have examined the differential benefits of exercise based on genetic risk for AD. Furthermore, evidence is limited regarding the potential moderating effects of ABCA7, a gene known to confer significantly greater AD risk in African Americans. In a case-control matched sample of 56 healthy older African Americans, we investigated the effect of an aerobic exercise intervention on a hippocampus-related assessment of generalization following rule learning, in individuals who were carriers of the ABCA7 rs3764650 non-risk (TT) or high-risk (GG) genotype. Following the exercise-intervention, the non-risk group made significantly fewer generalization errors, while there was no improvement in generalization for the high-risk group. For the controls, no changes in generalization scores were observed regardless of genotype status. Our results indicate that the ongoing adverse effects of ABCA7 high-risk genotype may diminish the benefits associated with aerobic exercise. As such, the potential disease-modifying effects of aerobic exercise on AD-related neuropathology may be limited to carriers of the ABCA7 rs3764650 non-risk genotype.

Evaluating the Memory Enhancing Effects of Angelica gigas in Mouse Models of Mild Cognitive Impairments

(1) Background: By 2050, it is estimated that 130 million people will be diagnosed with dementia, and currently approved medicines only slow the progression. So preventive intervention is important to treat dementia. Mild cognitive impairment is a condition characterized by some deterioration in cognitive function and increased risk of progressing to dementia. Therefore, the treatment of mild cognitive impairment (MCI) is a possible way to prevent dementia. Angelica gigas reduces neuroinflammation, improves circulation, and inhibits cholinesterase, which can be effective in the prevention of Alzheimer’s disease and vascular dementia and the progression of mild cognitive impairment. (2) Methods: Angelica gigas (AG) extract 1 mg/kg was administered to mildly cognitive impaired mice, models based on mild traumatic brain injury and chronic mild stress. Then, spatial, working, and object recognition and fear memory were measured. (3) Result: Angelica gigas improved spatial learning, working memory, and suppressed fear memory in the mild traumatic brain injury model. It also improved spatial learning and suppressed cued fear memory in the chronic mild stress model animals. (4) Conclusions: Angelica gigas can improve cognitive symptoms in mild cognitive impairment model mice.

Effect of Multicomponent Exercise and Nutrition Support on the Cognitive Function of Older Adults: A Randomized Controlled Trial

Purpose

This study compared the effects of a combination of soy peptide supplementation and exercise with those of exercise only, on the cognitive function of elderly adults.

Patients and methods

This randomized, non-blinded, controlled clinical trial included 67 participants aged 60 years or more with non-cognitive dysfunction who were divided into two groups according to the intervention method: an exercise group (Ex group, n = 36) and an exercise plus nutrition group (Ex+Nt group, n = 31). The Ex group completed a memory training activity for 15 mins and aerobic exercise for 45 mins once a week for 90 days. The Ex+Nt group completed the same training plus received soy peptide for 90 days. The Mini-Mental Status Examination score, trail-making test A/B score, skeletal muscle mass index, grip strength, gait speed, and geriatric depression scale were measured at baseline and post intervention. For comparison between the pretest and posttest measurements to determine the intervention effects, a two-way analysis of variance was performed. The significance level was set at < 5%.

Results

A two-way analysis of variance revealed significant time effects on trail-making test-A score, skeletal muscle index, grip strength, and gait speed in both groups. There were significant time x group interactions for greater increase in calculation score.

Conclusion

A combination of exercise and soy peptide supplementation was effective in improving a portion of cognitive function.

Gender Difference in the Effects of Outdoor Air Pollution on Cognitive Function Among Elderly in Korea

Background/Aim: Given a fast-growing aging population in South Korea, the prevalence of cognitive impairment in elderly is increasing. Despite growing evidence of air pollution exposure as one of the risk factors for declining cognition, few studies have been conducted on gender difference in the relation of cognitive function associated with outdoor air pollution. The aim of this study is to investigate the effect modification of gender difference in the association between cognitive function and air pollutant exposure (PM₁₀, PM_2.5−10, and NO₂).

Methods: The study focused on elderly, and the resulting sample included 1,484 participants aged 55 and older with no neurologic diseases, recruited from the four regions in Korea (Seoul, Incheon, Pyeongchang, and Wonju). We used the Mini-Mental State Examination (MMSE) score (with the conventional cut-off point “23–24”) to assess cognitive decline as the primary outcome of the study. Air pollution data used in this study were based on the 5-year average of predicted PM₁₀ and NO₂ concentrations, as well as the 2015 average PM_2.5 concentration. Additionally, a survey questionnaire was utilized to obtain information about general health assessment. To explore gender differences in the effects of air pollution exposure on cognitive function, we used penalized logistic regression, negative binomial regression, and generalized linear mixed model analyses. Subgroup analyses were also performed by the geographic location of residence (metropolitan vs. non-metropolitan).

Results: We found that women than men had a higher risk for decreased cognitive function associated with increased exposure to PM₁₀ and PM_2.5−10, respectively, even after adjustments for confounding factors (OR 1.01 [95%CI 1.00-1.03] in PM₁₀; OR 1.03 [95%CI 1.01–1.07] in PM_2.5−10). After stratification by metropolitan status, we also found that the adverse effect of NO₂ exposure on cognitive function was higher in women than men [OR 1.02 [95%CI 1.00–1.05] in metropolitan; OR 1.12 [95%CI 1.04–1.20] in non-metropolitan]. Notably, the magnitude of the effect sizes was greater among those in non-metropolitan regions than metropolitan ones.

Conclusions: Although our findings suggest that the adverse effects of outdoor air pollution on cognitive function appeared to be higher in women than men, this should be tentatively reflected due to some limitations in our results. While additional research is warranted to confirm or dispute our results, our findings suggest an indication of the need for developing and implementing prevention or interventions with a focus on elderly women with increased risk for air pollution exposure.

Physical activities attenuate the negative cognitive impact from white matter hyperintensities in stroke and TIA patients with low education

BACKGROUND

The objective of this study is to examine the effects of recent regular participation leisure activities upon cognitive functions between 3 and 6 months after stroke or transient ischemic attack (TIA). We also explored whether the cognitive effects interacted with the severity of white matter hyperintensities (WMH), a marker of cerebral white matter disease, in patients with low or high education.

METHODS

Two-hundred and ninety-two subjects with mean age of 66.1 (11.0) years were recruited at median 161(131-180) days post index event. WMH volume was evaluated using a semi-automated method on MRI brain. Cognitive functions were measured using the Montreal Cognitive Assessment (MoCA). Multivariable linear regression analysis was conducted to explore the associations between leisure activity participation with WMH and the moderating effects of leisure activities upon relationship between WMH and MoCA. Analyses were further stratified by low (<6 years) or high education (≥6 years). All models were adjusted with age, sex, and years of education.

RESULTS

Physical activity (PA), but not intellectual activity (IA), was negatively related to WMH volume (P < .05). IA exerted a main effect on MoCA performance (b = 3.21, P < .001). PA, but not IA, significantly interacted with WMH volume (b = -0.18, P < .01) on MoCA performance, but the interaction was only significant in the lower education group (b = 0.28, P < .01) but not in the higher education group.

CONCLUSIONS

In patients with stroke/TIA, IA confers general cognitive benefits. Regular participation in PA negatively correlated with WMH volume. In patients with low education, PA increases resilience against vascular cognitive impairment.

Physical Activity Is Associated With Lower Odds of Cognitive Impairment in Women but Not Men Living With Human Immunodeficiency Virus Infection

Background

Cardiovascular comorbidities are risk factors for human immunodeficiency virus (HIV)-associated cognitive impairment. Given differences in cardiometabolic risk profiles between women and men with HIV, we investigated whether associations between cardiometabolic risk factors and prevalent cognitive impairment differ by sex.

Methods

Separate logistic regression models were constructed for women and men at entry into a prospective study of older persons with HIV (PWH) to assess the association of cardiometabolic and other risk factors with cognitive impairment.

Results

Of 988 participants, 20% were women. Women had higher total cholesterol (194 vs 186 mg/dL; P = .027), hemoglobin A1c (5.9% vs 5.7%; P = .003), and body mass index (30.8 vs 27.4 kg/m2; P < .001) compared with men, and were less physically active (43% vs 55%; P = .005). In a multivariable model, physical activity was associated with lower odds of cognitive impairment in women (odds ratio, 0.35 [95% confidence interval, .15-.80]; P = .013) but not men.

Conclusions

Physical activity may have a greater positive impact on cognitive health in women than in men with HIV. This finding should be confirmed in studies examining the longitudinal association between physical activity and incident cognitive impairment in PWH and the effect of interventions that increase physical activity on cognitive impairment in women with HIV.

Aerobic Training and Mobilization Early Post-stroke: Cautions and Considerations

Knowledge gaps exist in how we implement aerobic exercise programs during the early phases post-stroke. Therefore, the objective of this review was to provide evidence-based guidelines for pre-participation screening, mobilization, and aerobic exercise training in the hyper-acute and acute phases post-stroke. In reviewing the literature to determine safe timelines of when to initiate exercise and mobilization we considered the following factors: arterial blood pressure dysregulation, cardiac complications, blood-brain barrier disruption, hemorrhagic stroke transformation, and ischemic penumbra viability. These stroke-related impairments could intensify with inappropriate mobilization/aerobic exercise, hence we deemed the integrity of cerebral autoregulation to be an essential physiological consideration to protect the brain when progressing exercise intensity. Pre-participation screening criteria are proposed and countermeasures to protect the brain from potentially adverse circulatory effects before, during, and following mobilization/exercise sessions are introduced. For example, prolonged periods of standing and static postures before and after mobilization/aerobic exercise may elicit blood pooling and/or trigger coagulation cascades and/or cerebral hypoperfusion. Countermeasures such as avoiding prolonged standing or incorporating periodic lower limb movement to activate the venous muscle pump could counteract blood pooling after an exercise session, minimize activation of the coagulation cascade, and mitigate potential cerebral hypoperfusion. We discuss patient safety in light of the complex nature of stroke presentations (i.e., type, severity, and etiology), medical history, comorbidities such as diabetes, cardiac manifestations, medications, and complications such as anemia and dehydration. The guidelines are easily incorporated into the care model, are low-risk, and use minimal resources. These and other strategies represent opportunities for improving the safety of the activity regimen offered to those in the early phases post-stroke. The timeline for initiating and progressing exercise/mobilization parameters are contingent on recovery stages both from neurobiological and cardiovascular perspectives, which to this point have not been specifically considered in practice. This review includes tailored exercise and mobilization prescription strategies and precautions that are not resource intensive and prioritize safety in stroke recovery.

Sex and Gender Driven Modifiers of Alzheimer's: The Role for Estrogenic Control Across Age, Race, Medical, and Lifestyle Risks

Research indicates that after advanced age, the major risk factor for late-onset Alzheimer’s disease (AD) is female sex. Out of every three AD patients, two are females with postmenopausal women contributing to over 60% of all those affected. Sex- and gender-related differences in AD have been widely researched and several emerging lines of evidence point to different vulnerabilities that contribute to dementia risk. Among those being considered, it is becoming widely accepted that gonadal steroids contribute to the gender disparity in AD, as evidenced by the “estrogen hypothesis.” This posits that sex hormones, 17β-estradiol in particular, exert a neuroprotective effect by shielding females’ brains from disease development. This theory is further supported by recent findings that the onset of menopause is associated with the emergence of AD-related brain changes in women in contrast to men of the same age. In this review, we discuss genetic, medical, societal, and lifestyle risk factors known to increase AD risk differently between the genders, with a focus on the role of hormonal changes, particularly declines in 17β-estradiol during the menopause transition (MT) as key underlying mechanisms.

Voluntary exercise and estradiol reverse ovariectomy-induced spatial learning and memory deficits and reduction in hippocampal brain-derived neurotrophic factor in rats

Ample evidences have demonstrated the beneficial effects of physical exercise on cognitive functions such as learning and memory. It is well established that female sex hormones have an important role in regulating learning and memory. This study was designed to investigate the effects of voluntary exercise and estrogen replacement on learning and memory deficits and reduction in hippocampal brain derived neurotrophic factor (BDNF) levels induced by ovariectomy. Ovariectomized rats were given daily vehicle or 17 β-estradiol (20 μg/kg) and allowed to freely exercise in a running wheel over the course of 2 weeks. After this period, they were trained and tested on a water-maze spatial task for 5 consecutive days, followed by a probe test one day later. At the end of the behavioral tests, all animals were decapitated and their hippocampal levels of BDNF were measured. Ovariectomy impaired spatial learning and memory and reduced hippocampal BDNF levels. Exercise significantly improved performance during both training and the retention of the water-maze task and increased hippocampal BDNF. Exercise, 17 β-estradiol and their combination recovered the impairing effects of ovariectomy on learning and memory performance. The combined treatment did not produce stronger effect than either exercise or 17 β-estradiol alone. Our findings provide an important evidence about positive influences of regular exercise and estrogen treatment against cognitive and BDNF deficits induced in ovariectomized rats, an experimental model of menopause.

Dose-Response Matters! - A Perspective on the Exercise Prescription in Exercise-Cognition Research

In general, it is well recognized that both acute physical exercises and regular physical training influence brain plasticity and cognitive functions positively. However, growing evidence shows that the same physical exercises induce very heterogeneous outcomes across individuals. In an attempt to better understand this interindividual heterogeneity in response to acute and regular physical exercising, most research, so far, has focused on non-modifiable factors such as sex and different genotypes, while relatively little attention has been paid to exercise prescription as a modifiable factor. With an adapted exercise prescription, dosage can be made comparable across individuals, a procedure that is necessary to better understand the dose-response relationship in exercise-cognition research. This improved understanding of dose-response relationships could help to design more efficient physical training approaches against, for instance, cognitive decline.

The effects of moderate exercise and overtraining on learning and memory, hippocampal inflammatory cytokine levels, and brain oxidative stress markers in rats

To investigate the exercise intensity effects on rats' memory and learning, animals were divided into control, moderate training (MT), and overtraining (OT) groups. At training last week, learning and memory was assessed using Morris water maze (MWM) and passive avoidance (PA) tests. Finally, the rat's brains were removed for evaluating oxidative stress and inflammatory cytokines. Overtraining impaired animal's performance in MWM and PA tests. In MT group, hippocampal levels of interleukin 1 beta (IL-1β) and malondialdehyde (MDA) increased, and thiol contents in hippocampal and cortical tissues decreased compared to control. In OT group, tumor necrosis factor α, IL-1β, and C-reactive protein hippocampal levels increased, MDA and nitric oxide metabolite in hippocampal and cortical tissues increased, thiol contents, catalase and superoxide dismutase activity in hippocampal and cortical tissues decreased compared to control and MT groups. Overtraining might lead to learning and memory impairment by increasing the inflammatory cytokine and oxidative stress markers.

Physical fitness and neurocognitive outcomes in adult survivors of childhood acute lymphoblastic leukemia: A report from the St. Jude Lifetime cohort

BACKGROUND

Survivors of childhood acute lymphoblastic leukemia (ALL) are at increased risk for both treatment-related exercise intolerance and neurocognitive deficits. This analysis aimed to identify the association between exercise intolerance and neurocognitive impairments in ALL survivors.

METHODS

Cardiopulmonary exercise testing, results from a 2-hour standardized neuropsychological assessment, and self-report questionnaires were obtained for 341 adult survivors of childhood ALL and 288 controls. Multivariable modeling was used to test associations between oxygen uptake at 85% estimated heart rate (rpkVO₂ ) and neuropsychological test and self-reported questionnaire domains, adjusted for sex, age at diagnosis, cranial radiation, anthracycline, and methotrexate exposure and tobacco smoking status.

RESULTS

Compared with controls, survivors had worse rpkVO₂ and performance on verbal intelligence, focused attention, verbal fluency, working memory, dominant/nondominant motor speed, visual-motor speed, memory span, and reading and math measures (all P < .001). In adjusted models, exercise intolerance was associated with decreases in performance of verbal ability, focused attention, verbal fluency, working memory, dominant motor speed, nondominant motor speed, visual-motor speed, memory span, reading academics, and math academics in survivors.

CONCLUSION

This study demonstrates an association between exercise intolerance and neurocognitive outcomes. Research is needed to determine whether interventions that improve exercise tolerance impact neurocognitive function in ALL survivors.

Exercise-driven restoration of the alcohol-damaged brain

There are vast literatures on the neural effects of alcohol and the neural effects of exercise. Simply put, exercise is associated with brain health, alcohol is not, and the mechanisms by which exercise benefits the brain directly counteract the mechanisms by which alcohol damages it. Although a degree of brain recovery naturally occurs upon cessation of alcohol consumption, effective treatments for alcohol-induced brain damage are badly needed, and exercise is an excellent candidate from a mechanistic standpoint. In this chapter, we cover the small but growing literature on the interactive neural effects of alcohol and exercise, and the capacity of exercise to repair alcohol-induced brain damage. Increasingly, exercise is being used as a component of treatment for alcohol use disorders (AUD), not because it reverses alcohol-induced brain damage, but because it represents a rewarding, alcohol-free activity that could reduce alcohol cravings and improve comorbid conditions such as anxiety and depression. It is important to bear in mind, however, that multiple studies attest to a counterintuitive positive relationship between alcohol intake and exercise. We therefore conclude with cautionary notes regarding the use of exercise to repair the brain after alcohol damage.

Is Benzodiazepine Use Associated With the Risk of Dementia and Cognitive Impairment–Not Dementia in Older Persons? The Canadian Study of Health and Aging

Background: The use of benzodiazepines in relation to cognitive decline remains an area of controversy in aging populations. Objective: This study aims to evaluate the risk of cognitive impairment–not dementia (CIND), Alzheimer disease (AD), and all-cause dementia with benzodiazepine use. The effect modification by sex was also investigated. Methods: Data come from the Canadian Study of Health and Aging, a 10-year multicentric study involving 10 263 participants randomly selected, 65 years and older, living in the community and in institutions. Current exposure to benzodiazepines was assessed in a face-to-face interview or self-reported in a questionnaire. Cox proportional hazard regression models, using age as time scale, were conducted to estimate hazard ratios, with adjustment for sex, education, smoking, alcohol intake, depression, physical activity, nonsteroidal anti-inflammatory drug use, and vascular comorbidities. Results: Data sets included 5281 participants for dementia as the outcome, 5015 for AD, and 4187 for CIND. Compared with nonusers, current use of benzodiazepines was associated with an increased risk of CIND (hazard ratio = 1.36; 95% CI = 1.08-1.72) in the simplest model. Results remained similar in the fully adjusted model (hazard ratio = 1.32; 95% CI = 1.04-1.68). There was no association between benzodiazepine use and the risk of dementia or AD. All these effects were similar between men and women. Conclusion and Relevance: Benzodiazepine use in older people from the general population is related to subsequent occurrence of cognitive dysfunction but not implicated in the pathogenesis of dementia or AD. Caution should be exercised when prescribing benzodiazepines to preserve global cognitive function.

Current and past leisure time physical activity in relation to risk of Alzheimer's disease in older adults

INTRODUCTION

The associations between self-reported current and past leisure time physical activity (LTPA) and Alzheimer's disease (AD) incidence were determined using data from the multiethnic Washington/Hamilton Heights-Inwood Columbia Aging Project (WHICAP) study.

METHODS

The metabolic equivalent of LTPA energy expenditure was calculated for self-reported current and past LTPA for 1345 older adults. A Cox proportional hazard model was conducted to estimate the association between LTPA (low, middle, and high) and incident AD risk.

RESULTS

Comparing high to low level, current and past LTPA were both associated with reduced AD risk, with hazard ratio (95% confidence interval) = 0.39 (0.20-0.75) and 0.37 (0.18-0.75), respectively. Compared with "always low," "increased" and "always high" LTPA throughout life were associated with reduced AD risk, with hazard ratio (95% confidence interval) = 0.60 (0.36-0.99) and 0.28 (0.08-0.94), respectively. Light- and moderate-intensity LTPA were associated with lower AD risk.

DISCUSSION

LTPA both throughout life and later in life are associated with lower risk of AD.

Associations of Physical Activity and β-Amyloid With Longitudinal Cognition and Neurodegeneration in Clinically Normal Older Adults

Importance

In the absence of disease-modifying therapies for Alzheimer disease, there is a critical need to identify modifiable risk factors that may delay the progression of Alzheimer disease.

Objective

To examine whether physical activity moderates the association of β-amyloid (Aβ) burden with longitudinal cognitive decline and neurodegeneration in clinically normal individuals and to examine whether these associations are independent of vascular risk.

Design, Setting, and Participants

This longitudinal observational study included clinically normal participants from the Harvard Aging Brain Study. Participants were required to have baseline Aβ positron emission tomography data, baseline medical data to quantify vascular risk, and longitudinal neuropsychological and structural magnetic resonance imaging data. Data were collected from April 2010 to June 2018. Data were analyzed from August to December 2018.

Main Outcomes and Measures

Baseline physical activity was quantified with a pedometer (mean steps per day). Baseline Aβ burden was measured with carbon 11-labeled Pittsburgh Compound B positron emission tomography. Cognition was measured annually with the Preclinical Alzheimer Cognitive Composite (PACC; median [interquartile range] follow-up, 6.0 [4.3-6.3] years). Neurodegeneration was assessed with longitudinal structural magnetic resonance imaging (2 to 5 scans per participant; median [interquartile range] follow-up, 4.5 [3.0-5.0] years), with a focus on total gray matter volume and regional cortical thickness. Physical activity and Aβ burden were examined as interactive predictors of PACC decline and volume loss in separate linear mixed models, adjusting for age, sex, education, apolipoprotein E ε4 status, and, where appropriate, intracranial volume. Secondary models adjusted for vascular risk and its interaction with Aβ burden.

Results

Of the 182 included participants, 103 (56.6%) were female, and the mean (SD) age was 73.4 (6.2) years. In models examining PACC decline and volume loss, there was a significant interaction of physical activity with Aβ burden, such that greater physical activity was associated with slower Aβ-related cognitive decline (β, 0.03; 95% CI, 0.02-0.05; P < .001) and volume loss (β, 482.07; 95% CI, 189.40-774.74; P = .002). Adjusting for vascular risk did not alter these associations. In these models, lower vascular risk was independently associated with slower Aβ-related PACC decline (β, -0.04; 95% CI, -0.06 to -0.02; P < .001) and volume loss (β, -483.41; 95% CI, -855.63 to -111.20; P = .01).

Conclusions and Relevance

Greater physical activity and lower vascular risk independently attenuated the negative association of Aβ burden with cognitive decline and neurodegeneration in asymptomatic individuals. These findings suggest that engaging in physical activity and lowering vascular risk may have additive protective effects on delaying the progression of Alzheimer disease.

Physical activity and incident dementia in older Japanese adults: The Okayama study

OBJECTIVE

To evaluate the association between regular physical activity and the risk of incident dementia in older Japanese adults.

METHODS

This was a retrospective cohort study performed in Okayama City, Japan. Overall, 51 477 older Japanese adults were followed from 2008 to 2014. A health checkup questionnaire was used to assess regular physical activity. The Dementia Scale of long-term care insurance was used as a measure of incident dementia. Cox proportional hazard models were used to calculate adjusted hazard ratios, with their 95% confidence intervals, for the incidence of dementia across the categories of physical activity.

RESULTS

During a 7-year follow-up, 13 816 subjects were considered as having incident dementia. Compared with participants who performed physical activity less than or equal to one time per week, the multivariate adjusted hazard ratio values (95% confidence intervals) for participants who performed physical activity greater than or equal to two times per week but not every day and those who performed physical activity every day were 0.79 (0.75-0.84) and 0.94 (0.89-0.98), respectively. The interaction of physical activity and sex was statistically significant (P < .01). In subgroup analysis, the multivariate-adjusted hazard ratio values (95% confidence intervals) remained low, at 0.76 (0.70-0.84) in males and 0.81 (0.76-0.87) in females who performed physical activity greater than or equal to two times per week but not every day; they were 0.82 (0.76-0.89) in males and 1.01 (0.95-1.07) in females who performed physical activity every day.

CONCLUSIONS

Regular physical activity could reduce the risk of incident dementia in older Japanese adults, except females who performed physical activity every day.

Born this way: Hippocampal neurogenesis across the lifespan

The capability of the mammalian brain to generate new neurons through the lifespan has gained much attention for the promise of new therapeutic possibilities especially for the aging brain. One of the brain regions that maintains a neurogenesis-permissive environment is the dentate gyrus of the hippocampus. Here, new neurons are generated from a pool of multipotent neural progenitor cells to become fully functional neurons that are integrated into the brain circuitry. A growing body of evidence points to the fact that neurogenesis in the adult hippocampus is necessary for certain memory processes, and in mood regulation, while alterations in hippocampal neurogenesis have been associated with a myriad of neurological and psychiatric disorders. More recently, evidence has come to light that new neurons may differ in their vulnerability to environmental and disease-related influences depending on the time during the life course at which they are exposed. Thus, it has been the topic of intense research in recent years. In this review, we will discuss the complex process and associated functional relevance of hippocampal neurogenesis during the embryonic/postnatal period and in adulthood. We consider the implications of hippocampal neurogenesis during the developmentally critical periods of adolescence and older age. We will further consider the literature surrounding hippocampal neurogenesis and its functional role during these critical periods with a view to providing insight into the potential of harnessing neurogenesis for health and therapeutic benefit.

Prevalence of Psychological Frailty in Japan: NCGG-SGS as a Japanese National Cohort Study

There has been less research conducted on the psychological aspects of frailty than on the physical and cognitive characteristics of frailty. Thus, we aimed to define psychological frailty, clarify its prevalence, and investigate the relationship between psychological frailty and lifestyle activity or disability incidence in older adults in Japan. The participants in our study were 4126 older adults (average age 71.7 years) enrolled in the National Center for Geriatrics and Gerontology-i87uStudy of Geriatric Syndromes (NCGG-SGS). We characterized physical frailty of the following as ≥ 3: slow walking speed, muscle weakness, exhaustion, low physical activity, and weight loss. We used the Geriatric Depression Scale 15 items version (GDS-15) to screen for depressive mood, indicated by 5 points or more on the scale. The co-presence of physical frailty and depressive mood was defined as psychological frailty. The incidence of disability was determined using data from the Japanese long-term care insurance system over 49 months. We found that the prevalence of physical frailty, depressive mood, and psychological frailty were 6.9%, 20.3%, and 3.5%, respectively. Logistic regression indicated that the odds ratios for loss of lifestyle activities were significantly higher in participants with psychological frailty for going outdoors using the bus or train, driving a car, using maps to go to unfamiliar places, reading books or newspapers, cognitive stimulation, culture lessons, giving advice, attending community meetings, engaging in hobbies or sports, house cleaning, fieldwork or gardening, and taking care of grandchildren or pets. During the follow-up period, 385 participants (9.3%) developed a disability. The incidence of disability was associated with both physical and psychological frailty in the fully adjusted model. However, no significant association between disability and depressive mood was found. We conclude that individuals with psychological frailty had the highest risk of disability. Future policies should implement disability prevention strategies among older adults with psychological frailty.

Cognitive Function and its Risk Factors Among Older US Adults Living at Home

BACKGROUND

The Montreal Cognitive Assessment (MoCA) has not been administered to a representative national sample, precluding comparison of patient scores to the general population and for risk factor identification.

METHODS

A validated survey-based adaptation of the MoCA (MoCA-SA) was administered to a probability sample of home-dwelling US adults aged 62 to 90, using the National Social Life, Health, and Aging Project (n=3129), yielding estimates of prevalence in the United States. The association between MoCA-SA scores and sociodemographic and health-related risk factors were determined.

RESULTS

MoCA-SA scores decreased with age, and there were substantial differences among sex, education, and race/ethnicity groups. Poor physical health, functional status, and depression were also associated with lower cognitive performance; current health behaviors were not. Using the recommended MoCA cut-point score for Mild Cognitive Impairment (MoCA score <26; MoCA-SA score <17), 72% (95% confidence interval, 69% to 74%) of older US adults would be classified as having some degree of cognitive impairment.

CONCLUSIONS

Our results provide an important national estimate for interpreting MoCA scores from individual patients, and establish wide variability in cognition among older home-dwelling US adults. Care should be taken in applying previously-established MoCA cut-points to the general population, especially when evaluating individuals from educationally and ethnically diverse groups.

Factors associated with poor physical performance in older adults of 11 Peruvian high Andean communities

Background: Physical performance in the older adult has been extensively studied. However, only a few studies have evaluated physical performance among older adults of high Andean populations and none have studied the factors associated with it. The objective of this study was to evaluate factors associated with poor physical performance by using the Short Physical Performance Battery (SPPB) in older adults living in 11 Peruvian high Andean communities.

Methods: An analytical cross-sectional study was carried out in inhabitants aged 60 or over from 11 high-altitude Andean communities of Peru during 2013-2017. Participants were categorized in two groups according to their SPPB score: poor physical performance (0-6 points) and medium/good physical performance (7-12 points). Additionally, we collected socio-demographic, medical, functional and cognitive assessment information. Poisson regression models were constructed to identify factors associated with poor physical performance. Prevalence ratio (PR) with 95% confidence intervals (95 CI%) are presented.

Results: A total of 407 older adults were studied. The average age was 73.0 ± 6.9 years (range: 60-94 years) and 181 (44.5%) participants had poor physical performance (0-6 points). In the adjusted Poisson regression analysis, the factors associated with poor physical performance were: female gender (PR=1.29; 95%CI: 1.03-1.61), lack of social support (PR=2.10; 95%CI: 1.17-3.76), number of drugs used (PR=1.09; 95%CI: 1.01-1.17), urinary incontinence (PR=1.45; 95%CI: 1.16-1.82), exhaustion (PR=1.35; 95%CI: 1.03-1.75) and cognitive impairment (PR=1.89; 95%CI: 1.40-2.55).

Conclusions: Almost half of the population evaluated had poor physical performance based on the SPPB. Factors that would increase the possibility of suffering from poor physical performance were: female gender, lack of social support, number of drugs used, urinary incontinence, exhaustion and cognitive impairment. Future studies with a larger sample and longitudinal follow-up are needed to design beneficial interventions for the high Andean population.

Enhancing effect of aerobic training on learning and memory performance in rats after long-term treatment with Lacosamide via BDNF-TrkB signaling pathway

Aerobic training has a neuroprotective effect, reduces the risk of developing neurodegenerative diseases and facilitates functional recovery. The present study assesses the effect of aerobic training on cognitive functions, hippocampal BDNF/TrkB ligand receptor system expression and serum levels of BDNF and corticosterone in intact rats after chronic treatment with Lacosamide (LCM). Male Wistar rats were randomly divided into two groups. One group was exercised on a treadmill (Ex) and the other one was sedentary (Sed). Half of the rats from each group received saline (veh) while the other half - LCM. The rats underwent a month-long training and LCM treatment before being subjected to one active and two passive avoidance tests. Both trained groups increased significantly the number of avoidances compared with the sedentary animals during the learning session and on memory retention tests, while the number of avoidances of the LCM-treated rats was significantly lower in comparison with the saline-treated animals. Both passive avoidance tests revealed that trained animals spent more time in the lighted compartment or caused longer stay on the platform than did the sedentary rats during acquisition and short- and long-term memory retention tests. Aerobic training increased BDNF and TrkB hippocampal immunoreactivity. We found no significant difference between BDNF serum levels but corticosterone levels of the Sed-LCM rats were lower than those of the Sed-veh animals. Our results show that aerobic training increases the hippocampal BDNF/TrkB expression suggesting a role in preventing the negative effect of Lacosamide on cognitive functions in rats.