Temporal relationship between handgrip strength and cognitive performance in oldest old people

Bidirectional association between grip strength and cognitive function in Chinese older adults: a nationwide cohort study

BACKGROUND

The rapid increase in the elderly population in China has led to the dual challenges of cognitive decline and physical functional decline. Grip strength, a key indicator of physical function, may have a bidirectional relationship with cognitive function. However, research on the association and bidirectional dynamics between the two, especially in the elderly population in China, remains limited.

OBJECTIVE

This study aims to investigate the longitudinal bidirectional associations between grip strength, global cognitive function, mental intactness, and episodic memory, and to examine the trajectory of these indicators over time.

METHODS

This study is based on the China Health and Retirement Longitudinal Study (CHARLS), which included 4,442 eligible individuals aged 60 and above, spanning from 2011 to 2015. Grip strength was measured using a standardized dynamometer, while global cognitive function was assessed through mental intactness and episodic memory metrics. Cross-lagged panel models and linear mixed-effects models were employed to assess the bidirectional associations between grip strength, global cognitive function, mental intactness, and episodic memory, controlling for various confounding factors, including sociodemographic characteristics.

RESULTS

During the 4-year follow-up, individuals with greater baseline grip strength exhibited higher scores in global cognitive function (β = 0.055, p = 0.001), mental intactness (β = 0.048, p = 0.006), and episodic memory (β = 0.049, p = 0.011) at follow-up. Baseline global cognitive function, mental intactness (β = 0.024, p = 0.019), and episodic memory (β = 0.040, p < 0.001) also significantly predicted grip strength at follow-up (β = 0.041, p < 0.001). A comparison of the cross-lagged coefficients revealed that the effect of baseline grip strength on episodic memory was significantly greater than the reverse pathway (Δχ2 = 5.089, p = 0.024). The linear mixed-effects model analysis further confirmed this result, showing that lower baseline cognitive function and weaker grip strength independently predicted the accelerated decline of both over time.

CONCLUSION

This study provides new evidence for the longitudinal bidirectional relationship between grip strength, global cognitive function, mental intactness, and episodic memory in the Chinese elderly population, emphasizing the importance of improving both grip strength and cognitive function. Notably, baseline grip strength has a stronger effect on subsequent episodic memory than the reverse pathway, which carries important public health implications. Maintaining optimal grip strength may be an effective intervention strategy to delay age-related cognitive decline.

Handgrip strength and risk of cognitive impairment across different glucose metabolism statuses: insights from the CHARLS study

Background

Both low handgrip strength (HGS) and abnormal glucose metabolism have been implicated in an increased risk of cognitive impairment. However, whether HGS interacts with glucose metabolism status to influence cognitive function remains unclear. This study explores the relationship between HGS and cognitive impairment risk among middle-aged and older Chinese adults and examines the potential modulation of this association by glucose metabolism status.

Methods

Data from the China Health and Retirement Longitudinal Study (CHARLS) collected in 2011 and 2018 were analyzed, including 7,301 participants aged ≥ 45 years. Cognitive impairment was the primary outcome. Logistic regression and restricted cubic spline (RCS) analyses were applied to evaluate the association between HGS and cognitive impairment risk across different glucose metabolism statuses.

Results

The study included 7,301 participants (mean age: 58.8 ± 8.9 years; 49.3% female). Over a 7-year follow-up, the mean cognitive function score declined from 12.05 ± 3.30 to 7.75 ± 5.70. After adjusting for confounders, logistic regression analyses indicated that higher HGS was significantly associated with a lower risk of cognitive impairment. Participants in the highest HGS quartile (Q4) had a significantly reduced odds of cognitive impairment compared to those in the lowest quartile (Q1) (odds ratio [OR]: 0.59, 95% confidence interval [CI]: 0.49-0.71; P < 0.001). RCS analysis demonstrated a significant negative linear correlation between HGS and cognitive impairment across individuals with normal glucose regulation, prediabetes, and diabetes (P < 0.001). The interaction p-value was 0.277, indicating no significant differences in this association among glucose metabolism subgroups.

Conclusion

Higher HGS is significantly associated with a reduced risk of cognitive impairment among middle-aged and older individuals, irrespective of glucose metabolism status. These findings suggest that HGS assessment could be a valuable universal tool for evaluating cognitive impairment risk, regardless of metabolic conditions.

The Temporal Relation of Physical Function with Cognition and the Influence of Brain Health in the Oldest-Old

INTRODUCTION

Physical function and cognition seem to be interrelated, especially in the oldest-old. However, the temporal order in which they are related and the role of brain health remain uncertain.

METHODS

We included 338 participants (mean age 93.1 years) from two longitudinal cohorts: the UCI 90+ Study and EMIF-AD 90+ Study. We tested the association between physical function (Short Physical Performance Battery, gait speed, and handgrip strength) at baseline with cognitive decline (MMSE, memory tests, animal fluency, Trail Making Test (TMT-) A, and digit span backward) and the association between cognition at baseline with physical decline (mean follow-up 3.3 years). We also tested whether measures for brain health (hippocampal, white matter lesion, and gray matter volume) were related to physical function and cognition and whether brain health was a common driver of the association between physical function and cognition by adding it as confounder (if applicable).

RESULTS

Better performance on all physical tests at baseline was associated with less decline on MMSE, memory, and TMT-A. Conversely, fewer associations were significant, but better scores on memory, TMT-A, and digit span backward were associated with less physical decline. When adding measures for brain health as confounder, all associations stayed significant except for memory with gait speed decline.

CONCLUSION

In the oldest-old, physical function and cognition are strongly related, independently of brain health. Also, the association between physical function and cognitive decline is more pronounced than the other way around, suggesting a potential for slowing cognitive decline by optimizing physical function.

INTRODUCTION

Physical function and cognition seem to be interrelated, especially in the oldest-old. However, the temporal order in which they are related and the role of brain health remain uncertain.

METHODS

We included 338 participants (mean age 93.1 years) from two longitudinal cohorts: the UCI 90+ Study and EMIF-AD 90+ Study. We tested the association between physical function (Short Physical Performance Battery, gait speed, and handgrip strength) at baseline with cognitive decline (MMSE, memory tests, animal fluency, Trail Making Test (TMT-) A, and digit span backward) and the association between cognition at baseline with physical decline (mean follow-up 3.3 years). We also tested whether measures for brain health (hippocampal, white matter lesion, and gray matter volume) were related to physical function and cognition and whether brain health was a common driver of the association between physical function and cognition by adding it as confounder (if applicable).

RESULTS

Better performance on all physical tests at baseline was associated with less decline on MMSE, memory, and TMT-A. Conversely, fewer associations were significant, but better scores on memory, TMT-A, and digit span backward were associated with less physical decline. When adding measures for brain health as confounder, all associations stayed significant except for memory with gait speed decline.

CONCLUSION

In the oldest-old, physical function and cognition are strongly related, independently of brain health. Also, the association between physical function and cognitive decline is more pronounced than the other way around, suggesting a potential for slowing cognitive decline by optimizing physical function.

The longitudinal bidirectional association between sarcopenia and cognitive function in community-dwelling older adults: Findings from the China Health and Retirement Longitudinal Study

Background

Although an association between sarcopenia and cognitive function has been demonstrated, the directional association remains unclear. The present study aimed to evaluate the longitudinal reciprocal relationship and identify the possible temporal sequence between sarcopenia and cognitive function in older Chinese adults.

Methods

Data were collected from the China Health and Retirement Longitudinal Study (CHARLS) baseline survey in 2011 and the follow-up survey in 2015. Cognitive function was measured by episodic memory and executive function. Sarcopenia status (non-sarcopenia, possible sarcopenia and sarcopenia) was defined based on the Asian Working Group for Sarcopenia 2019 criteria. Linear regression analysis and ordinal logistic regression analysis were employed to investigate the relationship between baseline sarcopenia status and follow-up cognition, as well as the association of baseline cognition with follow-up sarcopenia status, respectively. A cross-lagged panel analysis was performed to simultaneously evaluate the bidirectional association and the strength of the temporal relationship.

Results

Of 2689 participants, the median age was 65.0 years and 1249 (46.5%) were female. After adjusting for potential confounders and baseline measurements, baseline sarcopenia status was dose-dependently associated with subsequent cognitive scores (β = -0.45; P for trend = 0.001), and baseline cognitive scores (in tertiles) were also dose-dependently associated with subsequent sarcopenia status (odds ratio (OR) = 0.86; P for trend = 0.017). The cross-lagged panel analysis indicated that the standardised effect size of sarcopenia status on cognitive function (β = -0.09; P < 0.001) is larger relative to the effect of cognitive function on sarcopenia status (β = -0.05; P = 0.019).

Conclusions

There is a longitudinal, bidirectional relationship between sarcopenia status and cognitive function in older Chinese adults. Sarcopenia is likely the driving force in these dynamic associations. These findings imply that interventions in either sarcopenia or cognitive decline may have the ability to generate reciprocal benefits over time. More research is warranted to confirm these findings and to further elucidate underlying causal pathways.

Longitudinal Relationship Between Handgrip Strength and Cognitive Function in a European Multicentric Population Older Than 50 Years

OBJECTIVE

The aim of this study was to analyze the bidirectional association between handgrip strength (HGS) and cognitive performance in different cognitive functions in a European population and to evaluate the predictive validity of HGS for the risk of future cognitive impairment in aging individuals.

METHODS

This was a prospective cohort study conducted using data on individuals over 50 years of age from the Survey of Health, Aging and Retirement in Europe (SHARE). HGS measures and scores in numeracy, recall, and verbal fluency were repeated and analyzed biannually for 4 years and were used in generalized estimating equations to test the bidirectional association, categorized by sex.

RESULTS

Of the 8236 individuals included, 55.73% were women with a mean age of 67.55 (standard deviation [SD] = 8.4) years and 44.27% were men with a mean age of 68.42 (SD = 7.7) years. HGS predicted cognitive decline in both sexes, except for numeracy in men, even after adjustments. The strongest association with HGS in women was in verbal fluency (β = .094; 95% CI = 0.039 to 0.151), whereas the strongest association with HGS in men was in delayed verbal recall (β = .095; 95% CI = 0.039 to 0.151). Conversely, the greatest cognitive predictor of HGS decline was verbal fluency in men (β = .796; 95% CI = 0.464 to 1.128), and in women (β = .801; 95% CI= 0.567 to 1.109).

CONCLUSION

There is a significant and bidirectional association between HGS and different cognitive functions in a European multicentric population. This bidirectional association differed between sexes.

IMPACT

Both men and women who presented with cognitive decline also showed early changes in their HGS measures, and vice versa, but there still were differences between the sexes. These findings reinforce that HGS may be a simple and inexpensive method to identify early signs of cognitive decline, and that studies and rehabilitation strategies should be more sex specific.

Sustaining an ageing population: the role of micronutrients in frailty and cognitive impairment

Age-related frailty and cognitive decline are complex multidimensional conditions that significantly impact the ability of older adults to sustain functional capacity and independence. While underlying causes remain poorly understood, nutrition continually emerges as one associated risk element. Many studies have addressed the importance of adequate nutrition in delaying the onset of these conditions, but the specific role of micronutrients is not well established. The consideration of pre-frailty as an outcome variable is also limited in the current literature. In this review, we focus on the potential value of maintaining micronutrient sufficiency to sustaining the health of the ageing population. Using data from the Irish longitudinal study on ageing, we consider several vitamins known to have a high prevalence of low status in older adults and their impact on pre-frailty, frailty and cognitive impairment. They include vitamin B12 and folate, both of which are associated with multiple biological mechanisms involved in long-term health, in particular in cognitive function; vitamin D, which has been associated with increased risk of musculoskeletal disorders, depression and other chronic diseases; and the carotenoids, lutein and zeaxanthin, that may help mitigate the risk of frailty and cognitive decline via their antioxidant and anti-inflammatory properties. We show that low concentrations of folate and carotenoids are implicated in poorer cognitive health and that the co-occurrence of multiple nutrient deficiencies confers greatest risk for frailty and pre-frailty in the Irish longitudinal study on ageing cohort. These health associations contribute to evidence needed to optimise micronutrient status for health in the older adult population.

Exploratory and confirmatory factor analyses identify three structural dimensions for measuring physical function in community-dwelling older adults

Background

Physical function is a strong indicator of biological age and quality of life among older adults. However, the results from studies exploring the structural dimensions of physical function are inconsistent, and the measures assessed vary greatly, leading to a lack of comparability among them. This study aimed to construct a model to identify structural dimensions that are suitable and best assess physical function among community-dwelling adults 60-74 years of age in China.

Method

This study was conducted in 11 communities in Shanghai, China, from May to July 2021. A total of 381 adults 60-74 years of age were included in the study. Measured physical function data were used in factor analyses. Data collected from individuals were randomly assigned to either exploratory factor analysis (EFA) (n = 190) or confirmatory factor analysis (CFA) (n = 191). The statistical software used in the study was SPSS for EFA and AMOS for CFA. To test the properties of the structural dimension model of physical function, various fit indices, convergent validity, and discriminant validity were calculated.

Results

The EFA results derived seven indicators in three factors, with 58.548% of the total variance explained. The three factors were mobility function (three indicators), which explained 26.380% of the variance, handgrip strength and pulmonary function (two indicators), which explained 19.117% of the variance, and muscle strength (two indicators) which explained 13.050% of the variance. The CFA indicated that this model had an acceptable fit (χ2/df ratio, 2.102; GFI, 0.967; IFI, 0.960; CFI, 0.959; and RMSEA, 0.076), and the criteria for convergent validity and discriminability were also met by the model.

Conclusion

The constructed structural dimension model of physical function appeared to be a suitable and reliable tool to measure physical function in community-dwelling adults aged 60-74 years in China. The structural dimension indicators identified by this model may help sports medicine experts and healthcare providers offer more targeted interventions for older adults to reverse or slow the decline of physical function and to offer actionable targets for healthy aging in this population.

Recent Updates on Associations among Various Obesity Metrics and Cognitive Impairment: from Body Mass Index to Sarcopenic Obesity

Obesity and obesity-associated morbidity continues to be a major public health issue worldwide. Dementia is also a major health concern in aging societies and its prevalence has increased rapidly. Many epidemiologic studies have shown an association between obesity and cognitive impairment, but this relationship is not as well established as other comorbidities. Conflicting results related to the age and sex of participants, and the methodology used to define obesity and dementia may account for the uncertainty in whether obesity is a modifiable risk factor for dementia. More recently, sarcopenia and sarcopenic obesity have been reported to be associated with cognitive impairment. In addition, new mediators such as the muscle-myokine-brain axis and gut-microbiota-brain axis have been suggested and are attracting interest. In this review, we summarize recent evidence on the link between obesity and cognitive impairment, especially dementia. In particular, we focus on various metrics of obesity, from body mass index to sarcopenia and sarcopenic obesity.

Handgrip Strength and Cognitive Performance in a Multiethnic Cohort in Singapore

BACKGROUND

Handgrip strength (HGS) is an important marker of frailty but there is limited research on lifestyle and vascular determinants of HGS and its relationship with cognitive impairment.

OBJECTIVE

To identify determinants of HGS and the association of HGS with cognitive impairment in a multiethnic cohort from Singapore.

METHODS

This study (n = 2,109, median [Q1, Q3] age: 53 [48, 60] years, 59.6% women) was based on cross-sectional data from Singapore Multi-Ethnic Cohort. HGS was collected using hand-held Electronic Dynamometer. The potential determinants of HGS included age, sex, ethnicity, smoking, physical activity, serum cholesterol and history of hypertension, diabetes, and stroke. Cognition, assessed with the Mini-Mental State Examination (MMSE), was analyzed as both continuous and binary outcome (cognitively impaired [scores < 26] and cognitively normal [scores≥26]).

RESULTS

In total, 239 (11.3%) participants were cognitively impaired. Older age, female sex, Malay or Indian compared with Chinese ethnicity, and diabetes history were associated with decreased HGS, whereas higher education, higher body mass index, and more physical activity were associated with higher HGS. Higher HGS was associated with higher MMSE scores (β: 0.34, 95% CI: 0.20, 0.49) and 37% lower odds of cognitive impairment (OR: 0.63, 95% CI: 0.49-0.82). These associations were significantly stronger in participants who were older (50-90 years), female, of Malay and Indian ethnicity (compared with Chinese), and less educated.

CONCLUSION

In this multi-ethnic Asian population, demographics, vascular risk factors, and lifestyle behaviors were associated with HGS. Additionally, higher HGS was associated with substantially better cognitive function, which association was modified by age, sex, ethnicity, and education level.

Correlation between parameters related to sarcopenia and gray matter volume in patients with mild to moderate Alzheimer's disease

BACKGROUND

Alzheimer's disease (AD) is a neurodegenerative disease characterized by brain atrophy and closely correlated with sarcopenia. Mounting studies indicate that parameters related to sarcopenia are associated with AD, but some results show inconsistent. Furthermore, the association between the parameters related to sarcopenia and gray matter volume (GMV) has rarely been explored.

AIM

To investigate the correlation between parameters related to sarcopenia and cerebral GMV in AD.

METHODS

Demographics, neuropsychological tests, parameters related to sarcopenia, and magnetic resonance imaging (MRI) scans were collected from 42 patients with AD and 40 normal controls (NC). Parameters related to sarcopenia include appendicular skeletal muscle mass index (ASMI), grip strength, 5-times sit-to-stand (5-STS) time and 6-m gait speed. The GMV of each cerebral region of interest (ROI) and the intracranial volume were calculated by computing the numbers of the voxels in the specific region based on MRI data. Partial correlation and multivariate stepwise linear regression analysis explored the correlation between different inter-group GMV ratios in ROIs and parameters related to sarcopenia, adjusting for covariates.

RESULTS

The 82 participants included 40 NC aged 70.13 ± 5.94 years, 24 mild AD patients aged 73.54 ± 8.27 years and 18 moderate AD patients aged 71.67 ± 9.39 years. Multivariate stepwise linear regression showed that 5-STS time and gait speed were correlated with bilateral hippocampus volume ratios in total AD. Grip strength was associated with the GMV ratio of the left middle frontal gyrus in mild AD and the GMV ratios of the right superior temporal gyrus and right hippocampus in moderate AD. However, ASMI did not have a relationship to any cerebral GMV ratio.

CONCLUSIONS

Among parameters related to sarcopenia, 5-STS time and gait speed were associated with bilateral hippocampus volume ratios at different clinical stages of patients with AD. Five-STS time provide an objective basis for early screening and can help diagnose patients with AD.

Associations between grip strength, brain structure, and mental health in > 40,000 participants from the UK Biobank

BACKGROUND

Grip strength is a widely used and well-validated measure of overall health that is increasingly understood to index risk for psychiatric illness and neurodegeneration in older adults. However, existing work has not examined how grip strength relates to a comprehensive set of mental health outcomes, which can detect early signs of cognitive decline. Furthermore, whether brain structure mediates associations between grip strength and cognition remains unknown.

METHODS

Based on cross-sectional and longitudinal data from over 40,000 participants in the UK Biobank, this study investigated the behavioral and neural correlates of handgrip strength using a linear mixed effect model and mediation analysis.

RESULTS

In cross-sectional analysis, we found that greater grip strength was associated with better cognitive functioning, higher life satisfaction, greater subjective well-being, and reduced depression and anxiety symptoms while controlling for numerous demographic, anthropometric, and socioeconomic confounders. Further, grip strength of females showed stronger associations with most behavioral outcomes than males. In longitudinal analysis, baseline grip strength was related to cognitive performance at ~9 years follow-up, while the reverse effect was much weaker. Further, baseline neuroticism, health, and financial satisfaction were longitudinally associated with subsequent grip strength. The results revealed widespread associations between stronger grip strength and increased grey matter volume, especially in subcortical regions and temporal cortices. Moreover, grey matter volume of these regions also correlated with better mental health and considerably mediated their relationship with grip strength.

CONCLUSIONS

Overall, using the largest population-scale neuroimaging dataset currently available, our findings provide the most well-powered characterization of interplay between grip strength, mental health, and brain structure, which may facilitate the discovery of possible interventions to mitigate cognitive decline during aging.

An examination of the relationship among plasma brain derived neurotropic factor, peripheral vascular function, and body composition with cognition in midlife African Americans/Black individuals

African American/Black individuals have been excluded from several lines of prominent neuroscience research, despite exhibiting disproportionately higher risk factors associated with the onset and magnitude of neurodegeneration. Therefore, the objective of the current investigation was to examine potential relationships among brain derived neurotropic factor (BDNF), peripheral vascular function, and body composition with cognition in a sample of midlife, African American/Black individuals. Midlife adults (men: n = 3, 60 ± 4 years; women: n = 9, 58 ± 5 years) were invited to complete two baseline visits separated by 4 weeks. Peripheral vascular function was determined by venous occlusion plethysmography, a dual-energy X-ray absorptiometry was used to determine body composition, and plasma was collected to quantify BDNF levels. The CNS Vital Signs computer-based test was used to provide scores on numerous cognitive domains. The principal results included that complex attention (r = 0.629) and processing speed (r = 0.734) were significantly (p < 0.05) related to the plasma BDNF values. However, there was no significant (p > 0.05) relationship between any vascular measure and any cognitive domain or BDNF value. Secondary findings included the relationship between lean mass and peak hyperemia (r = 0.758) as well as total hyperemia (r = 0.855). The major conclusion derived from these results was that there is rationale for future clinical trials to use interventions targeting increasing BDNF to potentially improve cognition. Additionally, these results strongly suggest that clinicians aiming to improve cognitive health via improvements in the known risk factor of vascular function should consider interventions capable of promoting the size and function of skeletal muscle, especially in the African American/Black population.

Relationship between handgrip strength, depression and cognitive functioning among older adults: Evidence from longitudinal ageing study in India

BACKGROUND

Handgrip strength (HGS) is a frequent and general indicator of muscle strength and it may affect several aspects of mental health among older people. This study explored the association of HGS with depression and cognitive impairment among community-dwelling older adults in resource-constrained setting of India.

METHOD

Data were drawn from the Longitudinal Ageing Study in India (LASI), and the analysis was conducted on 27,707 older adults aged 60 years and above. Outcome measures included depression (assessed by the Short Form Composite International Diagnostic Interview (CIDI-SF) and the Center for Epidemiological Studies-Depression (CES-D) scales) and cognitive impairment. Descriptive statistics and mean scores of HGS were reported and multivariable linear regression analyses were conducted to test the research hypotheses of the study.

RESULTS

Mean score of HGS was 24.33 (SD: 7.22) for males and 15.94 (SD: 5.14) for females. Mean age was 68.86 (SD: 7.19) and 68.40 (SD: 7.31) years among males and females respectively. Older participants who had weak HGS were significantly more likely to be depressed in CIDI-SF scale (B: 0.06, CI: 0.01-0.13) and CES-D scale (B: 0.02, CI: 0.01-0.03) in comparison to those who had strong HGS after adjusting for a large number of confounders. Older participants who had weak HGS were significantly more likely (B: 0.92, CI: 0.76-1.07) to have cognitive impairment compared to those who had strong HGS.

CONCLUSION

The findings highlight the independent association of HGS with major depression, depressive symptoms and cognitive impairment that have implications on promoting resistance-training programs among aged population.

Grip Strength Trajectories and Cognition in English and Chilean Older Adults: A Cross-Cohort Study

Growing evidence about the link between cognitive and physical decline suggests the early changes in physical functioning as a potential biomarker for cognitive impairment. Thus, we compared grip-strength trajectories over 12-16 years in three groups classified according to their cognitive status (two stable patterns, normal and impaired cognitive performance, and a declining pattern) in two representative UK and Chilean older adult samples. The samples consisted of 7069 UK (ELSA) and 1363 Chilean participants (ALEXANDROS). Linear Mixed models were performed. Adjustments included socio-demographics and health variables. The Declined and Impaired group had significantly lower grip-strength at baseline when compared to the Non-Impaired. In ELSA, the Declined and Impaired showed a faster decline in their grip strength compared to the Non-Impaired group but differences disappeared in the fully adjusted models. In ALEXANDROS, the differences were only found between the Declined and Non-Impaired and they were partially attenuated by covariates. Our study provides robust evidence of the association between grip strength and cognitive performance and how socio-economic factors might be key to understanding this association and their variability across countries. This has implications for future epidemiological research, as hand-grip strength measurements have the potential to be used as an indicator of cognitive performance.

Pathophysiological mechanisms explaining the association between low skeletal muscle mass and cognitive function

Low skeletal muscle mass is associated with cognitive impairment and dementia in older adults. This review describes the possible underlying pathophysiological mechanisms: systemic inflammation, insulin metabolism, protein metabolism, and mitochondrial function. We hypothesize that the central tenet in this pathophysiology is the dysfunctional myokine secretion consequent to minimal physical activity. Myokines, such as fibronectin type III domain containing 5/irisin and cathepsin B, are released by physically active muscle and cross the blood–brain barrier. These myokines upregulate local neurotrophin expression such as brain-derived neurotrophic factor (BDNF) in the brain microenvironment. BDNF exerts anti-inflammatory effects that may be responsible for neuroprotection. Altered myokine secretion due to physical inactivity exacerbates inflammation and impairs muscle glucose metabolism, potentially affecting the transport of insulin across the blood–brain barrier. Our working model also suggests other underlying mechanisms. A negative systemic protein balance, commonly observed in older adults, contributes to low skeletal muscle mass and may also reflect deficient protein metabolism in brain tissues. As a result of age-related loss in skeletal muscle mass, decrease in the abundance of mitochondria and detriments in their function lead to a decrease in tissue oxidative capacity. Dysfunctional mitochondria in skeletal muscle and brain result in the excessive production of reactive oxygen species, which drives tissue oxidative stress and further perpetuates the dysfunction in mitochondria. Both oxidative stress and accumulation of mitochondrial DNA mutations due to aging drive cellular senescence. A targeted approach in the pathophysiology of low muscle mass and cognition could be to restore myokine balance by physical activity.

Association of Hand Grip Strength with Mild Cognitive Impairment in Middle-Aged and Older People in Guangzhou Biobank Cohort Study

Background: Lower hand grip strength has been linked to cognitive impairment, but studies in older Chinese are limited. We examined the association of hand grip strength with cognitive function in a large sample of older Chinese. Methods: 6806 participants aged 50+ years from the Guangzhou Biobank Cohort Study (GBCS) were included. Relative grip strength was calculated by absolute handgrip strength divided by the body mass index (BMI). Cognitive function was assessed using the Delayed Word Recall Test (DWRT, from 0 to 10) and the Mini Mental State Examination (MMSE, from 0 to 30), with higher scores indicating better cognition. Results: After adjusting for multiple potential confounders, lower absolute grip strength and relative grip strength were significantly associated with lower DWRT (all p < 0.05) in all participants. No significant interaction effects between sex and handgrip strength on cognitive impairment were found (p from 0.27 to 0.87). No significant association between handgrip strength and total MMSE scores was found in the total sample or by sex (p from 0.06 to 0.50). Regarding the individual components of MMSE, lower absolute and relative grip strength were significantly associated with lower scores of the recall memory performance in all participants (p from 0.003 to 0.04). Conclusion: We have shown for the first time a positive association of grip strength with recall memory performance, but not general cognitive function in older people, which warrants further investigation.

Effects of Intermittent Hypoxia-Hyperoxia Exposure Prior to Aerobic Cycling Exercise on Physical and Cognitive Performance in Geriatric Patients—A Randomized Controlled Trial

Background: It was recently shown that intermittent hypoxic-hyperoxic exposure (IHHE) applied prior to a multimodal training program promoted additional improvements in cognitive and physical performance in geriatric patients compared to physical training only. However, there is a gap in the literature to which extent the addition of IHHE can enhance the effects of an aerobic training. Therefore, the aim of this study was to investigate the efficacy of IHHE applied prior to aerobic cycling exercise on cognitive and physical performance in geriatric patients.

Methods: In a randomized, two-armed, controlled, and single-blinded trial, 25 geriatric patients (77–94 years) were assigned to two groups: intervention group (IG) and sham control group (CG). Both groups completed 6 weeks of aerobic training using a motorized cycle ergometer, three times a week for 20 min per day. The IG was additionally exposed to intermittent hypoxic and hyperoxic periods for 30 min prior to exercise. The CG followed the similar procedure breathing sham hypoxia and hyperoxia (i.e., normoxia). Within 1 week before and after the interventions, cognitive performance was assessed with the Dementia-Detection Test (DemTect) and the Clock Drawing Test (CDT), while physical performance was measured using the Timed “Up and Go” Test (TUG) and the Short-Physical-Performance-Battery (SPPB).

Results: No interaction effect was found with respect to the DemTect (η_p² = 0.02). An interaction effect with medium effect size (η_p² = 0.08) was found for CDT performance with a higher change over time for IG (d = 0.57) compared to CG (d = 0.05). The ANCOVA with baseline-adjustment indicated between-group differences with a large and medium effect size at post-test for the TUG (η_p² = 0.29) and SPPB (η_p² = 0.06) performance, respectively, in favour of the IG. Within-group post-hoc analysis showed that the TUG performance was worsened in the CG (d = 0.65) and remained unchanged in the IG (d = 0.19). Furthermore, SPPB performance was increased (d = 0.58) in IG, but no relevant change over time was found for CG (d = 0.00).

Conclusion: The current study suggests that an additional IHHE prior to aerobic cycling exercise seems to be more effective to increase global cognitive functions as well as physical performance and to preserve functional mobility in geriatric patients in comparison to aerobic exercise alone after a 6-week intervention period.

The Relationship Between Muscle Strength and Cognitive Performance Across Alzheimer's Disease Clinical Continuum

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by a progressive cognitive decline, mostly prominent in the domain of memory, but also associated with other cognitive deficits and non-cognitive symptoms. Reduced muscle strength is common in AD. However, the current understanding of its relationship with cognitive decline is limited. This study investigates the relationship between muscle strength and cognition in patients with AD and mild cognitive impairment (MCI). We enrolled 148 consecutive subjects, including 74 patients with probable AD dementia, 37 MCI, and 37 controls. Participants underwent neuropsychological evaluation focused on attention, working memory, declarative memory and learning. Muscle strength and muscle mass were measured through hand dynamometer and bio-electrical impedance analysis, respectively. Patients with AD dementia were divided with respect to the severity of cognitive impairment into mild and moderate-to-severe patients. Moderate-to-severe patients with AD presented lower handgrip strength than MCI and controls. No differences were observed in muscle mass. In MCI and AD dementia, handgrip strength was associated with overall cognitive functioning, attentional and memory performance. The routine implementation of handgrip strength assessment in the clinical work-up of patients with MCI and AD could potentially represent a simple method to monitor functional and cognitive decline along the disease course.

Association between Handgrip Strength and Cognitive Function in Older Adults: Korean Longitudinal Study of Aging (2006-2018)

Accumulating research indicates that handgrip strength is associated with cognitive function. Studies have also shown the difference in cognitive decline between males and females. We investigated the association between baseline handgrip strength and later cognitive function in older adults according to sex using the dataset from Korean Longitudinal Study of Aging (2006–2018). Overall, 9707 observations of 1750 participants (989 males and 761 females) over 65 years of age were sampled from the first wave, followed by six consecutive waves. The Korean version of the Mini-Mental State Examination and baseline handgrip strength scores were assessed. Sociodemographic and health-related variables were also included as covariates in the multivariable linear mixed models. Males in the lowest quartile of the baseline handgrip strength decreased in cognitive function (β = −0.54, standard error (SE) = 0.16, p < 0.001), compared to males in the highest quartile. For females, those in the second lowest quartile (β = −0.65, SE = 0.19, p < 0.001) and the lowest quartile (β = −0.53, SE = 0.19, p< 0.01) decreased in cognitive function. Handgrip strength may be positively associated with later cognitive function, but the association may be non-linear and differ between sexes. Sex-specific preventive assessment of handgrip strength may help identify older adults at risk for cognitive impairment.

Relationship among the quality of cognitive abilities, depression symptoms, and various aspects of handgrip strength in the elderly

Background/Aim. Both the cognitive and physical functioning changes occur within the normal aging, suggesting possible common biological processes. The aging process is often characterized by a reduction of adaptive responses, an increasing vulnerability and functional limitations. The aim of this study was to determine if there were correlations between particular cognitive abilities (verbal ability, spatial ability, processing speed, memory, verbal fluency, divergent thinking, memory, attention, executive functions, conceptualization, orientation, computation), depression symptoms and different dynamometric parameters of muscle contraction, during handgrip (HG) of both hands, in the elderly population. Methods. The sample consisted of 98 participants, 16 males and 82 females, aged from 65 to 85. Neuropsychological assessment included Montreal Cognitive Assessment (MoCA), Frontal Function Test (Go/No-Go), Categorical and Phonemic fluency tests and Geriatric Depression Scale Short Form (GDS-SF). Physical measures were assessed by Handgrip Dynamometry Tests (HG), and included: the maximum force (Fmax), maximal rate of force development (RFDmax), static endurance HG time realized at 50% of maximal HG force (tFmax50%) of dominant (Do) and non-dominant (NDo) hand. Results. Higher MoCA score was followed by higher values of muscle endurance of dominant hands. Higher values of F max of dominant hand were associated with higher values of Alternating Trail Making that is by visuoconstructive abilities (MoCA). The variable Categorical fluency was in a small, positive correlation with Fmax. No correlation of depressive symptoms with HG parameters was found except in the subgroup of female subjects. Conclusion. Better cognitive performance was associated with better HG muscle strength. Therefore, HG strength can be a useful tool in geriatric practice in monitoring not only physical, but also cognitive function status and de-cline. The link between lower cognitive functioning and lower values of HG variables, emphasize the need for in-creased awareness about it in clinical practice.

Cognitive and physical benefits of a game‐like dual‐task exercise among the oldest nursing home residents in Japan

Introduction

Dual‐task (DT) exercise can act as a substitute, which can help improve both physical and cognitive functions. Thus, this study investigated the effects of a game‐like cognitive DT exercise called “Synapsology” (SYNAP) among the oldest residents of a nursing home.

Methods

Participants (aged 85–97 years) were assigned to the intervention group (n = 12) and the control group (n = 12). The intervention group underwent 60‐minute sessions, twice a week for 24 weeks.

Results

A comparison of the Mini‐Mental State Examination scores and six physical function tests, before and after the intervention, shows that the SYNAP had a positive impact on the cognitive and physical functions among the intervention group.

Discussion

These findings suggest that SYNAP may help maintain or improve cognitive and physical functions among older adults compared to no interventions. Therefore, SYNAP would act as a beneficial tool amidst a “superaging” society like Japan.

Grip training improves handgrip strength, cognition, and brain white matter in minor acute ischemic stroke patients

OBJECTIVE

A large proportion of stroke patients experience cognitive impairment. Previous studies found that handgrip training can improve cognitive dysfunction after stroke through an unknown mechanism. In this study, we aimed to examine the influence of handgrip training on the cognition of patients with acute mild ischemic stroke and explore the mechanism using an advanced post-processing method for magnetic resonance imaging.

METHODS

Seventy-six patients with acute mild ischemic stroke were recruited for this study and randomly divided into a grip training group (n = 37) and a control group (n = 39). Both groups of patients also received standardized treatment for stroke in the acute phase and for secondary prevention, as well as conventional physical therapy after stroke. Grip strength, global cognitive function, and the local and global efficiencies of white matter networks derived from diffusion tensor images were measured before and after the 12-week training period.

RESULTS

In the within-group comparisons, grip training significantly improved the grip strength (3.52 [3.09-3.96], p = 0.02), Montreal Cognitive Assessment (MoCA) (2.27 [1.68-2.86], p = 0.05), and local, but not global, efficiency of the brain white matter network (0.03 [0.02-0.03], p = 0.02) in the experimental group. In contrast, these parameters were not statistically different over the same period in the control group. In the between-groups comparisons, the improvement of grip strength (2.71 [2.20-3.21], p = 0.01), MoCA (1.17 [0.39-1.95], p = 0.05), and local efficiency (0.02 [0.01-0.03], p = 0.01) showed statistically significant differences after the intervention, but not the absolute value of them, neither at the base line nor after the intervention.

CONCLUSIONS

Our results indicate that grip training can improve cognitive function by increasing the local efficiency of brain white matter connectivity. This suggests that white matter remodeling is a potential physiological mechanism connecting grip training and cognition improvement.

A Randomized Controlled Trial Protocol to Test the Efficacy of a Dual-Task Multicomponent Exercise Program vs. a Simple Program on Cognitive and Fitness Performance in Elderly People

BACKGROUND

The necessity of improve the life quality in elderly people is well-known. The aim of this study was to determine the effects of physical and cognitive training programs, as well as their combination on the cognitive functions and physical capacities in women over 80 years old.

METHODS

Forty-three women took part in this study (80.86 ± 5.03 years). They were divided into four groups (three experimental groups and one control group). Experimental group 1 performed cognitive training. Experimental group 2 did physical-cognitive training, and Experimental Group 3 accomplished physical training. All of training programs had duration of eight weeks (five sessions of 60 min per week). We measured cognitive variables with the Stroop test, D2 test, and Trail Making test. Physical variables were measured with handgrip strength, Minute Step Test, and visual-acoustic reaction time.

RESULTS

Control group reduces his physical and cognitive capacities, while the three experimental groups increase these capacities. We found a strong correlation between the increase of physical and cognitive capacities.

CONCLUSION

Eight weeks of training physical, cognitive or mixed, increased physical and cognitive functions of elderly people which may reduce the negative effects of the aging process.

Associations of sarcopenia and its defining components with cognitive function in community-dwelling oldest old

BACKGROUND

This study aimed to investigate the associations of sarcopenia and its defining components with cognitive function in community-dwelling oldest old (over 80 years old) in China.

METHODS

Sarcopenia was diagnosed by the 2019 Asian Working Group for Sarcopenia (AWGS) criteria. Cognitive function was evaluated by the Montreal Cognitive Assessment (MoCA). Logistic and linear regression models were used to explore the associations of sarcopenia and its defining components with risk of mild cognitive impairment (MCI), and performance on multiple cognitive domains among 428 adults aged 80 years and older.

RESULTS

The overall prevalence of sarcopenia was 35.5%, with 40.34% for men and 32.14% for women. The prevalence of MCI was higher among sarcopenic oldest old than non-sarcopenic oldest old (28.95% vs. 17.39%, p = 0.005). Multivariate logistic regression analyses showed that sarcopenia [odds ratio (OR) = 1.86, 95% confidence interval (CI): 1.04-3.33], low handgrip strength (HS) [OR = 2.33, 95% CI: 1.40-3.87] and slow gait speed (GS) [OR = 2.31, 95% CI: 1.13-4.72] were significantly and independently associated with risk of MCI. Multivariate linear regression analyses showed that low HS was associated with worse performance in global cognitive function, visuospatial and executive function, naming and delayed recall.

CONCLUSIONS

Sarcopenia, low HS and low GS was significantly associated with MCI in community-dwelling oldest old. The associations between sarcopenia and its defining components with different cognitive subdomains could be further explored in the future.

Sarcopenia and Cognitive Function: Role of Myokines in Muscle Brain Cross-Talk

Sarcopenia is a geriatric syndrome characterized by the progressive degeneration of muscle mass and function, and it is associated with severe complications, which are falls, functional decline, frailty, and mortality. Sarcopenia is associated with cognitive impairment, defined as a decline in one or more cognitive domains as language, memory, reasoning, social cognition, planning, making decisions, and solving problems. Although the exact mechanism relating to sarcopenia and cognitive function has not yet been defined, several studies have shown that skeletal muscle produces and secrete molecules, called myokines, that regulate brain functions, including mood, learning, locomotor activity, and neuronal injury protection, showing the existence of muscle-brain cross-talk. Moreover, studies conducted on physical exercise supported the existence of muscle-brain cross-talk, showing how physical activity, changing myokines' circulating levels, exerts beneficial effects on the brain. The review mainly focuses on describing the role of myokines on brain function and their involvement in cognitive impairment in sarcopenia.

From cognitive to motor impairment and from sarcopenia to cognitive impairment: a bidirectional pathway towards frailty and disability

Cognitive and motor/physical functions may evolve at different speeds along the entire lifespan, and with different impact on aging processes, although running parallel along the same temporal continuum. The investigation of the shared association between cognitive and motor/physical functions has represented a challenging subject of debate in the last decades. However, the direction of this cognitive-motor link still needs to be furtherly clarified. A first approach suggests that pre-clinical cognitive decline, such as the MCI, may have a negative impact also on strength, walking speed and balance. Conversely, the presence of earlier motor dysfunction has been discussed as a potential predictor of further cognitive impairment, such in the Motoric Cognitive Risk syndrome, which is characterized by primary reduced gait speed in absence of cognitive deficits. Moreover, reduced handgrip strength has been discussed as a risk factor for the onset of further cognitive impairment. Recent studies have started to investigate the association between cognitive and motor/physical functions in a bidirectional way, suggesting instead both the predictive role of strength on the onset of further cognitive decline, as well as the predictive role of cognitive status on progressively higher risk to develop strength reduction. In conclusion, cognitive and motor/physical decline could often identify a common way, rather than parallel pathways. This integrated perspective should be addressed in the context of geriatric assessments, and it may also promote an increasingly multi-dimensional approach to frailty, together with a significant concern in the end of life stages such as disability and mortality.

Skeletal Muscle Health and Cognitive Function: A Narrative Review

Sarcopenia is the loss of skeletal muscle mass and function with advancing age. It involves both complex genetic and modifiable risk factors, such as lack of exercise, malnutrition and reduced neurological drive. Cognitive decline refers to diminished or impaired mental and/or intellectual functioning. Contracting skeletal muscle is a major source of neurotrophic factors, including brain-derived neurotrophic factor, which regulate synapses in the brain. Furthermore, skeletal muscle activity has important immune and redox effects that modify brain function and reduce muscle catabolism. The identification of common risk factors and underlying mechanisms for sarcopenia and cognition may allow the development of targeted interventions that slow or reverse sarcopenia and also certain forms of cognitive decline. However, the links between cognition and skeletal muscle have not been elucidated fully. This review provides a critical appraisal of the literature on the relationship between skeletal muscle health and cognition. The literature suggests that sarcopenia and cognitive decline share pathophysiological pathways. Ageing plays a role in both skeletal muscle deterioration and cognitive decline. Furthermore, lifestyle risk factors, such as physical inactivity, poor diet and smoking, are common to both disorders, so their potential role in the muscle-brain relationship warrants investigation.

Effects of Aerobic and Resistance Exercise Interventions on Cognitive and Physiologic Adaptations for Older Adults with Mild Cognitive Impairment: A Systematic Review and Meta-Analysis of Randomized Control Trials

(1) Background: The purpose of this meta-analysis is to investigate the effects of exercise intervention for older adults with mild cognitive impairment (MCI). (2) Methods: Databases including PubMed, Medline, and Cochrane were used to search for studies that reported effects of exercise for older adults with MCI and randomized controlled trials up to July 2020. Exercise interventions of all selected studies were summarized, and effect sizes of exercise interventions were calculated. (3) Results: A total of 14 studies, including 1178 older adults with MCI were included. Exercise participation in older adults with MCI improved cognitive functions (d = 0.88, 95% confidence interval [CI]; 0.10-1.65, p = 0.01; k = 5]) and handgrip strength (d = 0.62, 95% [CI]; 0.23-1.01, p = 0.00; k = 4) compared with control groups. Aerobic exercise or resistance exercise at moderate to vigorous levels for at least 150 min, 1 time/week, for 6 weeks was the minimum level to obtain beneficial effects from exercise for older adults with MCI. (4) Conclusions: Older adults with MCI who participated in exercise received beneficial effects, including improvement in cognitive functions and handgrip strength, but further studies to confirm the effects are needed.

Handgrip strength, tumor necrosis factor-α, interlukin-6, and visfatin levels in oldest elderly patients with cognitive impairment

INTRODUCTION

Handgrip strength is associated with mild cognitive impairment. Tumor necrosis factor [TNF]-α and interleukin [IL]-6 were pro-inflammatory cytokines influencing the severity of initial neurological deficit. Visfatin is a novel adipokine and has a strong correlation with inflammation. The relationships of TNF-α, IL-6 and visfatin are not consistent, and no study has investigated them in the elderly patients with cognitive impairment.

METHODS

This study included patients aged ≥75 years at the emergency department from August 2018 to February 2019. All patients underwent comprehensive geriatric assessment and blood tests for fasting plasma TNF-α, IL-6 and visfatin levels.

RESULTS

We enrolled 106 elderly patients with a mean age of 87.3 years, including 62 (58.4%) patients in cognitive impairment group (Mini-Mental State Examination [MMSE] < 24) and 44 (41.5%) patients in the non-cognitive impairment group. Compared to the non-cognitive impairment group, the cognitive impairment group had significantly lower handgrip strength, and significantly higher TNF-α, IL-6 and visfatin levels. TNF-α positively correlated with IL-6. Both TNF-α and IL-6 negatively correlated with Barthel index and MMSE. Handgrip strength negatively correlated with TNF-α but positively correlated with Barthel index and MMSE scores. Backward and stepwise multiple logistic regression analyses showed that the independent predictor for cognitive impairment was handgrip strength and age.

CONCLUSION

The cognitive impairment group had significantly higher serum TNF-α, IL-6, and visfatin levels. The independent predictors of cognitive impairment were handgrip strength and age. Handgrip strength negatively correlated with TNF-α and IL-6 but positively with Barthel index and MMSE scores.

Distinct Trajectories of Individual Physical Performance Measures Across 9 Years in 60- to 70-Year-Old Adults

Background

Physical performance is an important factor for successful aging. This study aimed to identify distinct trajectories of multiple physical performance measures over 9 years in individuals aged 60–70 years and to evaluate their characteristics and the overlap between measures.

Methods

Four physical performance measures were assessed in 440 participants of the Longitudinal Aging Study Amsterdam: tandem stand, gait speed, chair stand, and handgrip strength. Gender-specific latent class models were conducted to obtain distinct trajectories and their degree of overlap.

Results

Mean age at baseline was 67.9 (SD 1.7) years for males and 68.0 (SD 1.7) years for females. The optimal number of trajectories differed across measures. For tandem stand, no distinct trajectories were found (all 179 males, 198 females). For gait speed, three trajectories were identified, dependent on baseline speed: high-stable (47 males, 27 females), intermediate-stable (132 males, 130 females), and low-declining performance (6 males, 48 females). Two trajectories were identified for the chair stand: a stable (168 males, 150 females) and declining trajectory (10 males, 38 females). For handgrip strength, three declining trajectories were identified differing in baseline performance: high (55 males, 75 females), intermediate (111 males, 118 females), and low (17 males, 10 females). Overall, 11.9% of males and 5.7% of females were classified in similar trajectories across measures.

Conclusions

Trajectories of physical performance were heterogeneous, but showed similar patterns for males and females. Little overlap between measures was shown, suggesting different mechanisms for decline. This study emphasizes the use of multiple domains to assess physical performance.

Associations of Brain Pathology Cognitive and Physical Markers With Age in Cognitively Normal Individuals Aged 60-102 Years

The prevalence of brain pathologies increases with age and cognitive and physical functions worsen over the lifetime. It is unclear whether these processes show a similar increase with age. We studied the association of markers for brain pathology cognitive and physical functions with age in 288 cognitively normal individuals aged 60-102 years selected from the cross-sectional EMIF-AD PreclinAD and 90+ Study at the Amsterdam UMC. An abnormal score was consistent with a score below the 5th percentile in the 60- to 70-year-old individuals. Prevalence of abnormal scores was estimated using Generalized Estimating Equations (GEE) models. The prevalence of abnormal handgrip strength, the Digit Symbol Substitution Test, and hippocampal volume showed the fastest increase with age and abnormal MMSE score, muscle mass, and amyloid aggregation the lowest. The increase in prevalence of abnormal markers was partly dependent on sex, level of education, and amyloid aggregation. We did not find a consistent pattern in which markers of brain pathology cognitive and physical processes became abnormal with age.

What determines cognitive functioning in the oldest-old? The EMIF-AD 90+ Study

OBJECTIVES

Determinants of cognitive functioning in individuals aged 90 years and older, the oldest-old, remain poorly understood. We aimed to establish the association of risk factors, white matter hyperintensities (WMH), hippocampal atrophy and amyloid aggregation with cognition in the oldest-old.

METHODS

We included 84 individuals without cognitive impairment and 38 individuals with cognitive impairment from the EMIF-AD 90+ Study (mean age 92.4 years) and tested cross-sectional associations between risk factors (cognitive activity, physical parameters, nutritional status, inflammatory markers and cardiovascular risk factors), brain pathology biomarkers (WMH and hippocampal volume on MRI, and amyloid binding measured with PET) and cognition. Additionally, we tested whether the brain pathology biomarkers were independently associated with cognition. When applicable, we tested whether the effect of risk factors on cognition was mediated by brain pathology.

RESULTS

Lower values for handgrip strength, Short Physical Performance Battery (SPPB), nutritional status, HbA1c and hippocampal volume, and higher values for WMH volume and amyloid binding were associated with worse cognition. Higher past cognitive activity and lower BMI were associated with increased amyloid binding, lower muscle mass with more WMH, and lower SPPB scores with more WMH and hippocampal atrophy. The brain pathology markers were independently associated with cognition. The association of SPPB with cognition was partially mediated by hippocampal volume.

DISCUSSION

In the oldest-old, physical parameters, nutritional status, HbA1c, WMH, hippocampal atrophy and amyloid binding are associated with cognitive impairment. Physical performance may affect cognition through hippocampal atrophy. This study highlights the importance to consider multiple factors when assessing cognition in the oldest-old.

The Bidirectional Association Between Physical and Cognitive Function Among Chinese Older Adults: A Mediation Analysis

This study investigated the bidirectional association between physical and cognitive function in later life and examined the mechanisms underlying the interrelationship. We employed cross-lagged panel models to analyze a sample of 4232 unique participants aged 65 years and older from three waves of the Chinese Longitudinal Healthy Longevity Survey. Physical activity and social participation were tested as potential mediators between physical and cognitive function. Our findings revealed a reciprocal relationship between physical and cognitive function and a reciprocal relationship between physical and cognitive decline. Moreover, physical activity was confirmed to mediate the bidirectional association between physical and cognitive function, whereas social participation did not seem to be a mediator. A vicious cycle linking physical and cognitive decline may exist in Chinese older adults. However, leading a physically active lifestyle could be an effective intervention to slow physical and cognitive aging, thereby toning down the vicious cycle.

Sex- and age-specific mild cognitive impairment is associated with low hand grip strength in an older Chinese cohort

Background

Few studies have demonstrated the impact of characteristics like age and sex on the association between hand grip strength (HGS) and mild cognitive impairment (MCI). In this cross-sectional study, we aimed to examine the effects of sex and age on the relationship between HGS and MCI.

Methods

We enrolled older adults age ≥60 years (n = 1009) and measured HGS and MCI in all participants. We analyzed the differences in MCI prevalence among the different variables. The role of sex and age in the association between MCI and HGS was analyzed using binary logistic regression.

Results

Women had significantly higher prevalence of MCI than men, as did the older group (age ≥70 years) compared with the younger group (age 60–70 years). In men, the low and middle HGS tertiles were significantly associated with MCI. In contrast, only the low tertile of HGS was associated with MCI in women. In the older group, the low tertile of HGS was significantly associated with MCI, which was not observed in the younger group.

Conclusions

HGS was associated with MCI in older adults, and this association was stronger in men. HGS may be useful for evaluating MCI in older adults.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

The Sequence of Physical and Cognitive Impairment and the Association with Mortality Among Unimpaired Older Mexican Adults

BACKGROUND

Many older adults become physically and cognitively impaired. However, it is unclear whether unimpaired older adults are more likely to become physically or cognitively impaired first and if this sequence impacts mortality risk.

METHODS

Data came from the Mexican Health and Aging Study. The sample included 1,283 participants aged ≥60 years who were physically and cognitively unimpaired in 2001. Multinomial logistic regression was used to estimate probabilities of being unimpaired, cognitively impaired only, physically impaired only, or cognitively-physically impaired in 2003. Proportional hazard models were used to estimate mortality risk through 2015 according to physical and cognitive status in 2003.

RESULTS

The probabilities for being unimpaired, physically impaired only, cognitively impaired only, and cognitively-physically impaired in 2003 were 0.45, 0.22, 0.19, and 0.13, respectively. Older age, female sex, and arthritis were associated with significantly greater probability of becoming physically impaired only than cognitively impaired only in 2003. Cognitive impairment only (hazard ratio [HR] = 1.42, 95% confidence interval [CI] = 1.09-1.85) in 2003 but not physical impairment only (HR = 1.22, 95% CI = 0.94-1.58) was associated with greater mortality than being unimpaired in 2003. Cognitively-physically impaired participants had higher mortality risk than participants who were physically (HR = 1.58, 95% CI = 1.18-2.12) or cognitively (HR = 1.36, 95% CI = 1.01-1.84) impaired only.

DISCUSSION

The likelihood of becoming only physically or cognitively impaired over 2 years varies by demographic and health characteristics. The mortality risk for unimpaired older adults who become cognitively impaired only is similar to those who become physically impaired only. Research should determine if the sequence of cognitive and physical impairments is associated with other outcomes.

The Longitudinal Associations of Handgrip Strength and Cognitive Function in Aging Americans

OBJECTIVES

Factors that are responsible for age-related neurologic deterioration of noncognitive and cognitive processes may have a shared cause. We sought to examine the temporal, directional associations of handgrip strength and cognitive function in a national sample of aging Americans.

DESIGN

Longitudinal panel.

SETTING

Enhanced interviews that included physical, biological, and psychosocial measures were completed in person. Core interviews were often conducted over the telephone.

PARTICIPANTS

The analytic sample included 14,775 Americans aged at least 50 years who participated in at least 2 waves of the 2006-2016 waves of the Health and Retirement Study.

MEASURES

Handgrip strength was measured with a hand-held dynamometer. Participants were considered cognitively intact, mildly impaired, or severely impaired according to the Telephone Interview of Cognitive Status questionnaire. Separate lagged general estimating equations analyzed the directional associations of handgrip strength and cognitive function.

RESULTS

The overall time to follow-up was 2.1 ± 0.4 years. Every 5 kg higher handgrip strength was associated with 0.97 [95% confidence interval (CI) 0.93, 0.99] lower odds for both future cognitive impairment and worse cognitive impairment. Those who were not weak had 0.54 (CI 0.43, 0.69) lower odds for future cognitive impairment and 0.57 (CI 0.46, 0.72) lower odds for future worse cognitive impairment. Conversely, any (β = -1.09; CI -1.54, -0.64), mild (β = -0.85; CI -1.34, -0.36), and severe cognitive impairment (β = -2.34; CI -3.25, -1.42) predicted decreased handgrip strength. Further, the presence of any, mild, and severe cognitive impairment was associated with 1.82 (CI 1.48, 2.24), 1.65 (CI 1.31, 2.08), and 2.53 (CI 1.74, 3.67) greater odds for future weakness, respectively.

CONCLUSIONS/IMPLICATIONS

Strength capacity and cognitive function may parallel each other, whereby losses of functioning in 1 factor may forecast losses of functioning in the other. Handgrip strength could be used for assessing cognitive status in aging Americans and strength capacity should be monitored in those with cognitive impairment.

Measurement of hand grip strength in the elderly: A scoping review with recommendations

INTRODUCTION

Hand grip strength has been widely used as a lead measure in geriatric conditions such as frailty. However, diversity in assessment protocols and methodologies creates uncertainty in the comparison of outcome measurements. The aim of this study was to review the literature relating to the measurement of hand grip strength in older adults, in order to develop further consensus in relation to the use of existing protocols in clinical and community settings, with an emphasis on practicality and suitability for frail persons.

METHODS

Five electronic English databases were searched using keywords such as 'hand grip strength', 'clinimetric assessment', and their synonyms. Age-related trends in adults aged ≥65 years were assessed, and comparisons were made of the following variables: dynamometer model and handle setting, hand positioning, warm-up trials, grip duration, number of repeated tests, rest periods, laterality of tested hand, and whether encouragement was given to the subjects.

RESULTS

Thirty-four research papers met the inclusion criteria and were included. A Jamar hand dynamometer was most frequently used. Variations were found in the positioning of the subject and in the duration of the rest period, which ranged from 10 to 20 s to 1 min. Grip strength was typically measured three times in the dominant hand, with the strongest grip being recorded and no encouragement being provided during assessment.

CONCLUSIONS

Based on the scoping review, we propose a detailed and standardised protocol that is suitable for the assessment of hand grip strength in frail older adults.

Associations Between Aging-Related Changes in Grip Strength and Cognitive Function in Older Adults: A Systematic Review

OBJECTIVES

Grip strength and cognitive function reflect upper body muscle strength and mental capacities. Cross-sectional research has suggested that in old age these two processes are moderately to highly associated, and that an underlying common cause drives this association. Our aim was to synthesize and evaluate longitudinal research addressing whether changes in grip strength are associated with changes in cognitive function in healthy older adults.

METHODS

We systematically reviewed English-language research investigating the longitudinal association between repeated measures of grip strength and of cognitive function in community-dwelling older adults to evaluate the extent to which the two indices decline concurrently. We used four search engines: Embase, PsychINFO, PubMed, and Web of Science.

RESULTS

Of 459 unique citations, 6 met our full criteria: 4 studies reported a longitudinal association between rates of change in grip strength and cognitive function in older adults, 2 of which reported the magnitudes of these associations as ranging from low to moderate; 2 studies reported significant cross-sectional but not longitudinal associations among rates of change. All studies concluded that cognitive function and grip strength declined, on average, with increasing age, although with little to no evidence for longitudinal associations among rates of change.

CONCLUSIONS

Future research is urged to expand the study of physical and cognitive associations in old age using a within-person and multi-study integrative approach to evaluate the reliability of longitudinal results with greater emphasis on the magnitude of this association.

SYSTEMATIC REVIEW REGISTRATION NUMBER

CRD42016038544.

Evaluation of the directional relationship between handgrip strength and cognitive function: the Korean Longitudinal Study of Ageing

BACKGROUND

recent studies suggest that handgrip strength is linked with cognitive impairment at older ages. However, it remains unclear as to whether muscular strength influences subsequent cognitive performance, or whether lower levels of cognitive function increase the likelihood of muscle strength decline.

OBJECTIVE

to investigate the directional relationship between handgrip strength and cognitive impairment using longitudinal data among older adults.

METHODS

repeated measures of handgrip strength and cognitive function were collected in a sample of 5,995 participants of the Korean Longitudinal Study of Aging (KLoSA) over a period of 8 years. Time-lagged general estimating equations, while accounting for correlation among repeated measures, was used to assess the temporal effect of handgrip strength on cognitive impairment and vice versa with adjustment for other confounding factors.

RESULTS

after adjustment, greater handgrip strength was related to subsequent reduction in the risk of cognitive impairment, such that participants in the highest quartile presented approximately 50% decrease in their risk of cognitive impairment [adjusted odds ratio (OR) = 0.499 (95% CI 0.422 to 0.589] compared to the lowest quartile after controlling for potential confounding factors. Conversely, cognitive impairment was a significant predictor of reduced muscular strength [β regression coefficient -0.804, 95% CI, -1.168 to -0.439, for participants with dementia compared with those with normal cognitive function].

CONCLUSIONS

in conclusion, a significant bi-directional relationship was found between muscular strength and cognitive function, suggesting that these may have shared common pathways that are worthy of being further elucidated in future studies.

Associations between handgrip strength and mild cognitive impairment in middle-aged and older adults in six low- and middle-income countries

OBJECTIVES

A number of small-scale, single-country studies have suggested that muscular weakness may be a biomarker for cognitive health, mild cognitive impairment (MCI), and dementia. However, multinational, representative studies are lacking, particularly from low- and middle-income countries (LMICs). Thus, we assessed the association between muscular strength (measured by maximal handgrip) and MCI in six LMICs (China, Ghana, India, Mexico, Russia, and South Africa), using nationally representative data.

METHODS

Cross-sectional, community-based data on individuals aged 50 years or older from the World Health Organization's Study on Global Ageing and Adult Health were analyzed. MCI was defined according to the National Institute on Aging-Alzheimer's Association criteria. Weak handgrip strength was defined as less than 30 kg for men and less than 20 kg for women using the average value of two handgrip measurements of the dominant hand. Multivariable logistic regression analysis was conducted to assess the association between muscular strength and MCI.

RESULTS

A total of 32 715 participants were included (mean age 62 ± SD 15.6 y and 51.7% female). The prevalence of MCI and weak handgrip strength was 15.3% (95% CI, 14.4%-16.3%) and 46.5% (95% CI, 43.6%-49.5%), respectively. After adjustment for potential confounders, weak handgrip strength was associated with 1.41 (95% CI, 1.23-1.61) times higher odds for MCI. The corresponding figures for those aged 50 to 64 years and 65 years or older were 1.35 (95% CI, 1.14-1.60) and 1.54 (95% CI, 1.27-1.86), respectively.

CONCLUSIONS

Muscular weakness may provide a clinically useful indicator of MCI risk. Increasing our understanding of the connection between muscular and cognitive function could ultimately lead to the development and broader implementation of resistance training interventions targeting both physical and cognitive health.

The effect of inspiratory muscle training on the quality of life, immune response, inspiratory and lower limb muscle strength of older adults: a randomized controlled trial

Abstract Objective: To evaluate the impact of inspiratory muscle training (IMT) on the quality of life, immune response, inspiratory and lower limb muscle strength of older adults. Method: A randomized clinical trial was conducted with 30 institutionalized older adults. They were allocated into two groups: the IMT group (n=15), which underwent IMT with PowerBreathe Classic, using a load of 60% of maximal inspiratory pressure (MIP). This was performed using a 30 repetition protocol, three times a week, for six weeks. The second group was the control group (n=15) which did not perform any type of therapeutic intervention. In both groups, MIP, lower limb strength by sit-up test, quality of life by the SF-36 questionnaire and C-reactive protein (CRP) were evaluated. Results: The results demonstrated the homogeneity between the groups regarding the demographic and clinical variables. The IMT group showed an increase in the variation of MIP (9.20±7.36 cmH2O) compared to the control (0.93±8.79 cmH2O). Improvement was also observed in the sitting and standing test (p<0.05) (Tukey Test) in the difference between the values before and after the IMT. In terms of quality of life, two of the eight SF-36 domains were influenced by the IMT, namely: functional capacity and limitations due to physical factors. There were no changes in CRP in either group. Conclusion: IMT improved the inspiratory muscle strength, lower limb strength and quality of life of institutionalized older adults. These findings reinforce the contribution of this therapy to reducing the deleterious effects of aging.

Decline in Handgrip Strength From Midlife to Late-Life is Associated With Dementia in a Japanese Community: The Hisayama Study

BACKGROUND

The association between decline in handgrip strength from midlife to late life and dementia is unclear.

METHODS

Japanese community-dwellers without dementia aged 60 to 79 years (ie, individuals in late life; mean age, 68 years) were followed for 24 years (1988-2012) (n = 1,055); 835 of them had participated in a health examination in 1973-1974 (mean age, 53 years), and these earlier data were used for the midlife analysis. Using a Cox proportional hazards model, we estimated the risk conferred by a decline in handgrip strength over a 15-year period (1973-74 to 1988) from midlife to late life on the development of total dementia, Alzheimer's disease (AD), and vascular dementia (VaD) over the late-life follow-up period from 1988 to 2012.

RESULTS

During the follow-up, 368 subjects experienced total dementia. The age- and sex-adjusted incidence of total dementia increased significantly with greater decline in handgrip strength (increased or unchanged handgrip strength [≥+0%] 25.1, mildly decreased [-14 to -1%] 28.4, and severely decreased [≤-15%] 38.9 per 1,000 person-years). A greater decline in handgrip strength was significantly associated with higher risk of total dementia after adjusting for potential confounding factors; subjects with severely decreased handgrip strength had 1.51-fold (95% confidence interval, 1.14-1.99, P < 0.01) increased risk of total dementia compared to those with increased or unchanged handgrip strength. Similar significant findings were observed for AD, but not for VaD.

CONCLUSIONS

Our findings suggest that a greater decline in handgrip strength from midlife to late life is an important indicator for late-life onset of dementia.

Sarcopenia and its association with changes in socioeconomic, behavioral, and health factors: the EpiFloripa Elderly Study

This study aimed to verify the prevalence of sarcopenia and its association with changes in socioeconomic, behavioral, and health factors in the elderly. The longitudinal population-based study included 598 elderly (≥ 60 years) in Florianópolis, Santa Catarina State, in the South of Brazil. Sarcopenia was defined on the basis of appendicular skeletal mass index (ASMI) according to gender (ASMI < 7.26kg/m² for men and < 5.5kg/m² for women). We assessed changes that occurred between the two study waves (2009/2010 and 2013/2014) in relation to socioeconomic, behavioral, and health factors. Crude and adjusted logistic regression analyses were performed. Prevalence of sarcopenia was 17% in women (95%CI: 12.4-22.9) and 28.8% in men (95%CI: 21.3-37.7). In the final model, women that continued to consume or that started consuming alcohol (OR = 0.31; 95%CI: 0.11-0.91) showed lower odds of sarcopenia. Women who continued to smoke or that started smoking (OR = 2.55; 95%CI: 1.16-5.58) and/or that remained inactive or became insufficiently active (OR = 2.90; 95%CI: 1.44-5.84) showed higher odds of sarcopenia. For men, no change variable was associated with sarcopenia. The results suggest that continuing or starting to smoke and remaining or becoming physically inactive are preventable and modifiable risk factors for sarcopenia.

Association between chronic diseases and handgrip strength in older adults residents of Florianópolis - SC, Brazil

This paper aims to verify the association between chronic diseases and handgrip strength (HS) in the older adults of Florianópolis, SC. This is a cross-sectional analysis of a longitudinal population-based study. HS was measured by dynamometer. Independent variables included 10 chronic diseases and falls. Simple and multiple linear regression analyses were performed. In the final model, in women, arthritis/rheumatism/arthrosis (β: -1.27; 95%CI: -2.55; -0.20) was associated with lower HS and bronchitis/ asthma (β: 1.61, 95%CI: 0.21; 3.00) was associated with higher HS. Regarding men, in the final model, diabetes (β:-3.78; 95%CI: -6.51; -1.05) was associated with lower HS. The trend analysis evidenced a lower HS with increased number of chronic diseases in both genders. There was an association between some chronic diseases and HS, with differences between genders. ĩt is essential to overhaul health policies aimed at maintaining the independence and autonomy of the older adults population.

Association among handgrip strength, body mass index and decline in cognitive function among the elderly women

Background

The association between handgrip strength combined with body mass index (BMI) and cognitive impairment has not been thoroughly examined. We aimed to investigate whether the relationship between handgrip strength and risk of cognitive impairment is altered by the presence of obesity in older women.

Methods

A total of 544 older women aged over 65 years without cognitive impairment from the Korean Longitudinal Study of Aging (KLoSA) were included in the study. Handgrip strength was classified in a binary manner (weak or strong) or in tertiles and obesity was defined as a BMI ≥ 25 kg/m², in accordance with the Asia-Pacific World Health Organization criteria. Incident cognitive impairment was defined as a Korean Mini-mental State Examination (K-MMSE) score of less than 24 after eight years of follow-up.

Results

Strong handgrip strength was associated with reduced likelihood of developing cognitive impairment compared to weak handgrip strength in obese women (adjusted odds ratio, aOR 0.23, 95% confidence interval, CI 0.08–0.66). The highest tertile of handgrip strength was associated with reduced risk of incident cognitive impairment (aOR 0.16, 95% CI 0.04–0.70), compared to the lowest tertile of handgrip strength in obese women, with a significant linear trend (p for trend = 0.016). Furthermore, the highest tertile of handgrip strength was significantly associated with smaller decline in K-MMSE scores compared to the lowest tertile of handgrip strength in obese women (p value = 0.009). There was no association between handgrip strength and incident cognitive impairment in non-obese women.

Conclusions

Strong handgrip strength was associated with reduced risk of cognitive impairment among obese women, but not in non-obese women. Handgrip strength may be a simple and useful marker for predicting future cognitive impairment among obese women.

Electronic supplementary material

The online version of this article (10.1186/s12877-018-0918-9) contains supplementary material, which is available to authorized users.

Comparison of motor skill learning, grip strength and memory recall on land and in chest-deep water

Immersion in chest-deep water may augment explicit memory in healthy adults however, there is limited information on how this environment might affect implicit memory or motor learning. The purpose of this study was to compare the speed and accuracy for learning a motor skill on land and in chest-deep water. Verbal word recall and grip strength were included to gain a more complete understanding of the intervention. Sixty-two younger adults (age = 23.3 ± 3.59 yrs.) were randomly assigned to either a water group immersed to the xiphoid or a land group. Participants in both groups completed the same eight practice trials of a mirror-drawing task on two separate days. Outcome measures for this task included time and error numbers to complete each drawing. The number of words recalled using a 12 word recall test, and peak grip strength using a hand dynamometer were measured each day of testing. The influence of environment and repeated practice on each outcome measure were assessed with an analysis of variance and effect sizes (ES). Time and errors for both groups significantly decreased with practice (p < 0.01, ES = 0.11-0.28), however the drawing time was greater in water than on land for trials 1, 5, and 6 (ES = 0.50-0.55). There was a 7% increase in words recalled (9.24 ± 1.19 vs 8.60 ± 1.19) and a 16% increase in grip strength (405 ± 104 vs 342 ± 83) for water than land groups (ES 0.54-0.64). Healthy adults in chest-deep water and on land display comparable mirror-drawing speed and accuracy after minimal practice. Curiously, water immersion may augment verbal word recall and grip strength abilities.

Get a grip: individual variations in grip strength are a marker of brain health

Demonstrations that grip strength has predictive power in relation to a range of health conditions-even when these are assessed decades later-has motivated claims that hand-grip dynamometry has the potential to serve as a "vital sign" for middle-aged and older adults. Central to this belief has been the assumption that grip strength is a simple measure of physical performance that provides a marker of muscle status in general, and sarcopenia in particular. It is now evident that while differences in grip strength between individuals are influenced by musculoskeletal factors, "lifespan" changes in grip strength within individuals are exquisitely sensitive to integrity of neural systems that mediate the control of coordinated movement. The close and pervasive relationships between age-related declines in maximum grip strength and expressions of cognitive dysfunction can therefore be understood in terms of the convergent functional and structural mediation of cognitive and motor processes by the human brain. In the context of aging, maximum grip strength is a discriminating measure of neurological function and brain health.

Handgrip Strength Cannot Be Assumed a Proxy for Overall Muscle Strength

OBJECTIVES

Dynapenia, low muscle strength, is predictive for negative health outcomes and is usually expressed as handgrip strength (HGS). Whether HGS can be a proxy for overall muscle strength and whether this depends on age and health status is controversial. This study assessed the agreement between HGS and knee extension strength (KES) in populations differing in age and health status.

DESIGN

Data were retrieved from 5 cohorts.

SETTING AND PARTICIPANTS

Community, geriatric outpatient clinics, and a hospital. Five cohorts (960 individuals, 49.8% male) encompassing healthy young and older individuals, geriatric outpatients, and older individuals post hip fracture were included.

MEASURES

HGS and KES were measured according to the protocol of each cohort. Pearson correlation was performed to analyze the association between HGS and KES, stratified by sex. HGS and KES were standardized into sex-specific z scores. The agreement between standardized HGS and standardized KES at population level and individual level were assessed by intraclass correlation coefficients (ICC) and Bland-Altman analysis.

RESULTS

Pearson correlation coefficients were low in healthy young (male: 0.36 to 0.45, female: 0.45) and healthy older individuals (male: 0.35 to 0.37, female: 0.44), and moderate in geriatric outpatients (male and female: 0.54) and older individuals post hip fracture (male: 0.44, female: 0.57) (P < .05, except for male older individuals post hip fracture [P = .07]). Intraclass correlation coefficient values were poor to moderate in all populations (ie, healthy young individuals [0.41, 0.45], healthy older individuals [0.37, 0.41, 0.44], geriatric outpatients [0.54], and older individuals post hip fracture [0.54]). Bland-Altman analysis showed that within the same population of age and health status, agreement between HGS and KES varied on individual level.

CONCLUSIONS

At both population and individual level, HGS and KES showed a low to moderate agreement independently of age and health status. HGS alone should not be assumed a proxy for overall muscle strength.