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

Relationship between falls, cognitive decline, and dementia in older adults: Insights from the Korean longitudinal study of aging, 2006-2020

Limited research has explored the relationship between falls, cognitive decline, and dementia onset in older adults with aging. Therefore, this study aimed to investigate the impact of cognitive function on the development of dementia and explore the association between falls and dementia among older adults. This study utilized data from the Korean Longitudinal Study of Aging, which tracked a sample group at 2-year intervals from the initial wave in 2006 to the eighth wave in 2020. Among the older adults (≥60 years) surveyed, 2829 were included in the analysis, and cognitive function and number of falls per year were recorded. We hypothesized that these variables were associated with dementia and tested the variables using dementia diagnosis data. The participants were assigned to either a dementia group (dementia diagnosis) or a control group (no dementia diagnosis). Analyses were performed to enhance generalizability of the hypothesis to all participants (≥45 years, n = 7130). Cognitive decline and dementia incidence increased with aging among older adults. The dementia group had a significantly higher rate of cognitive decline than the control group, as well as a higher number of falls and magnitude of annual changes in falls. The changes in falls were irregular regardless of cognitive function. Furthermore, falls were associated only with the development of dementia, not cognitive function. Similar trends were observed across the total participant group. Our findings highlight the importance of monitoring cognitive function and falls as potential markers for predicting dementia onset in older adults.

Prevalence of mild cognitive impairment and modifiable risk factors: A cross-sectional study in rural older adults with diabetes

To determine the prevalence and modifiable risk factors for MCI in older adults with T2DM in rural China. This cross-sectional study encompassed 96 villages, employing a cluster sampling approach to recruit eligible older adults with T2DM as study participants. Logistic regression analysis was utilized to identify modifiable risk factors associated with MCI. Average marginal effects were calculated. The discriminatory performance of these risk factors in identifying MCI was evaluated by plotting the receiver operating curve and calculating the value of the area under the curve. A total of 898 older adults with T2DM in our study. The overall prevalence of MCI was 50.22 %. Independent associations with MCI were found in poor self-management ability of diabetes (OR = 0.808, 95 % CI: 0.808, 0.766), depressive symptoms (OR = 3.500, 95 % CI: 1.933, 6.337), moderate (OR = 0.936, 95 % CI: 0.017, 0.075) and high (OR = 0.939, 95 % CI: 0.016, 0.100) levels of physical activity, poorer oral health (OR = 2.660, 95 % CI: 2.226, 3.179), and lower grip strength (OR = 0.913, 95 % CI: 0.870, 0.958). The AUC was 0.967 (95 % CI 0.508-0.470). The prevalence of MCI was high among older adults with T2DM in rural areas of China. The self-management ability of diabetes, depressive symptoms, physical activity, oral health and grip strength were modifiable risk factors of MCI. Targeted interventions should be developed and implemented to address these modifiable risk factors, aiming to enhance cognitive function and mitigate the incidence of MCI in older adults with T2DM.

Factors associated with handgrip strength across the life course: A systematic review

BACKGROUND

Muscle strength is essential for healthy ageing. Handgrip strength (HGS) has been recommended by expert bodies as the preferred measure of muscle strength, in addition to being considered a strong predictor of overall health. Cross-sectional studies have shown several potential factors associated with HGS, but a systematic review of factors predicting HGS over time has not previously been conducted. The aim of this study is to systematically review the literature on the factors associated with adult HGS [at follow-up(s) or its rate of change] across the life course.

METHODS

Searches were performed in MEDLINE via Ebsco, Embase and SPORTDiscus databases. Longitudinal studies assessing potential factors impacting adult HGS over time were included in the analyses. Based on previously established definitions of consistency of results, a semiquantitative analysis was conducted using the proportions of studies supporting correlations with HGS.

RESULTS

A total of 117 articles were included in this review. Factors associated with HGS were grouped into 11 domains: demographic, socioeconomic, genetic, early life, body composition, health markers/biomarkers, health conditions, psychosocial, lifestyle, reproductive and environmental determinants. Overall, 103 factors were identified, of which 10 showed consistent associations with HGS over time (i.e., in at least four studies with ≥60% agreement in the direction of association). Factors associated with greater declines in HGS included increasing age, male sex, higher levels of inflammatory markers and the presence of cardiovascular diseases. Education level, medication use, and self-rated health were not associated with the rate of change in HGS. Increased birth weight was associated with a stronger HGS over time, whereas depressive symptoms were linked to a weaker HGS, and smoking habits showed null associations.

CONCLUSIONS

Comparison between studies and estimation of effect sizes were limited due to the heterogeneity in methods. Although sex and age may be the main drivers of HGS decline, it is crucial to prioritize modifiable factors such as inflammation and cardiovascular diseases in health interventions to prevent greater losses. Interventions to improve birth weight and mental health are also likely to produce positive effects on muscle strength. Our results point to the complexity of processes involving muscle strength and suggest that the need to better understand the determinants of HGS remains.

Longitudinal Associations Between Cognition and Grip Strength, Differentiated by Sex and Physical Activity: A Population-Based Study in Older Adults From 17 European Countries

Objectives (1) To investigate longitudinal associations between grip strength (GS) and cognition over 4 years in European older adults, (2) to examine differences in temporal associations between men and women and between levels of physical activity, (3) to explore in each year 2015 and 2019 associations between GS quartiles and cognitive performance, and (4) to explore longitudinal associations between GS quartiles (year 2015) and cognitive performance (year 2019). Methods: 25,281 individuals (14,200 women) from 17 European countries aged ≥50 years responded to waves 6th and 8th of the SHARE project. We analyzed GS, a general cognition index, and physical activity level. Results: Panel analyses revealed a bidirectional relationship over 4 years between GS and cognition, with differences between sex, as well as between participants with moderate-to-vigorous and low physical activity levels. Conclusion: Women and participants with low physical activity were more likely to experience cognitive performance deficits 4 years later.

Longitudinal relationship between grip strength and cognitive function in a European population older than 50 years: A cross-lagged panel model

OBJECTIVES

The aim of this study was to investigate the dynamic longitudinal relationship between grip strength and cognitive function.

METHODS

6175 participants aged ≥50 years were included in the study using three waves of follow-up data from the Survey of Health, Ageing, and Retirement in Europe in 2015 (T1), 2017 (T2) and 2019 (T3). Cognitive function was assessed using numeracy, verbal fluency, immediate recall, delayed recall and total. The cross-lagged panel model was used for analysis.

RESULTS

There was a correlation between grip strength and cognitive function. Standardized path coefficient from numeracy T1 to grip strength T2 was 0.017 (p = 0.003), and from numeracy T2 to grip strength T3 was 0.014 (p = 0.012). Standardized path coefficient from grip strength T1 to numeracy T2 was 0.096 (p < 0.001), and from grip strength T2 to numeracy T3 was 0.113 (p < 0.001). Other indicators of cognitive function had similar relationships with grip strength.

CONCLUSIONS

The study found a statistically significant longitudinal and bidirectional relationship between grip strength and cognitive function in a sample of people aged ≥50 years from several European countries.

The Grip Strength Loss Rate and the Subsequent Cognitive Decline Rate in Older Adults: The Moderating Role of Social Isolation

Background and Objectives

Accumulating evidence suggests that low grip strength (GS) is associated with a faster cognitive decline, but most previous studies have measured GS at a single time point, ignoring changes in GS. We aimed to explore the association of the GS loss rate with the sequent cognitive decline, as well as the moderating role of social isolation in older adults.

Research Design and Methods

Data were from the English Longitudinal Study of Ageing. Absolute and relative GS loss rates were calculated as the annual losses from Wave 2 (2004-05) to Wave 4 (2008-09). Participants were divided into 3 groups according to the tertiles of GS loss rates. Linear mixed models were used to assess the association of the GS loss rate during Waves 2-4 with the cognitive decline rate during Waves 4-9 (Wave 9, 2018-19).

Results

Of the 4 356 participants included in analyses, 1 938 (44.5%) were men, with a mean age of 68.4 (SD: 8.4) years. Compared with Tertile 1 of the absolute GS loss rate, Tertile 2 (β = -0.009 [95% CI: -0.018 to -0.001] SD/year) and Tertile 3 (β = -0.018 [95% CI: -0.027 to -0.010] SD/year) were associated with a faster cognitive decline rate. The results of relative GS were similar to those of absolute GS. Social isolation was a significant modifier in the associations of the absolute GS loss rate with decline rates in global cognition and episodic memory, but not in temporal orientation. We did not observe that social isolation moderated the association of the relative GS loss rate with the cognitive decline rate.

Discussion and Implications

Both absolute and relative GS loss rates were positively associated with the cognitive decline rate in older adults. Low social isolation scores attenuated the association of the absolute GS loss rate with the cognitive decline rate.

Higher handgrip strength is linked to higher salience ventral attention functional network segregation in older adults

Converging evidence suggests that handgrip strength is linked to cognition in older adults, and this may be subserved by shared age-related changes in brain function and structure. However, the interplay among handgrip strength, brain functional connectivity, and cognitive function remains poorly elucidated. Hence, our study sought to examine these relationships in 148 community-dwelling older adults. Specifically, we examined functional segregation, a measure of functional brain organization sensitive to ageing and cognitive decline, and its associations with handgrip strength and cognitive function. We showed that higher handgrip strength was related to better processing speed, attention, and global cognition. Further, higher handgrip strength was associated with higher segregation of the salience/ventral attention network, driven particularly by higher salience/ventral attention intra-network functional connectivity of the right anterior insula to the left posterior insula/frontal operculum and right midcingulate/medial parietal cortex. Importantly, these handgrip strength-related inter-individual differences in salience/ventral attention network functional connectivity were linked to cognitive function, as revealed by functional decoding and brain-cognition association analyses. Our findings thus highlight the importance of the salience/ventral attention network in handgrip strength and cognition, and suggest that inter-individual differences in salience/ventral attention network segregation and intra-network connectivity could underpin the handgrip strength-cognition relationship in older adults.

The relationship between handgrip strength and cognitive function among older adults in China: Functional limitation plays a mediating role

BACKGROUND

The deterioration of cognitive function with age has become a major public health issue. To date, the underlying mechanisms of the association between handgrip strength and cognitive function were poorly understood. This study aimed to examine the mediating effect of functional limitation in the longitudinal relationship between handgrip strength and subsequent cognitive function.

METHODS

This research recruited 4416 participants aged 60 and above from wave 2015 and 2018 of the China Longitudinal Study of Health and Retirement (CHARLS). We conducted the linear regression model and bootstrap analyses to test the mediating role of functional limitation in the relationship between handgrip strength and cognitive function.

RESULTS

After adjusting the confounders, handgrip strength was positively associated with subsequent cognitive function (β = 0.12, P < 0.001) and was negatively associated with functional limitation (β = -0.14, P < 0.001). The mediation effect of functional limitation accounted for 23.33 % of the total effect regarding the handgrip strength with cognitive function, and the magnitude of mediation effect was a*b = 0.021 (95%CI: 0.017-0.027).

LIMITATIONS

The variable of functional limitations was self-reported. And this study did not analyse the severity and duration of handgrip strength loss and functional limitations, which may lose some information.

CONCLUSIONS

Our findings revealed that handgrip strength not only directly influenced cognitive function among older individuals but also indirectly via functional limitation over 3-year follow-up. Physical exercise targeting handgrip strength and functional limitation may be an effective approach to prevent and delay cognitive decline.

Handgrip strength asymmetry and cognitive impairment risk: Insights from a seven-year prospective cohort study

OBJECTIVES

This study aimed to explore the links of handgrip strength and asymmetry with cognitive impairment.

DESIGN

This was a seven-year prospective cohort study.

SETTING AND PARTICIPANTS

We used data from wave 3 (2015-2017) to wave 5 (2019-2022) from the ongoing Taiwan Initiative of Geriatric Epidemiological Research (TIGER), with wave 3 as the baseline (n = 446). The study included community-dwelling participants aged 65 years or older.

MEASUREMENTS

Handgrip strength was measured, and abnormalities were determined based on handgrip strength weakness and asymmetry. Handgrip strength asymmetry was categorized into three groups at baseline based on the handgrip strength ratio (left handgrip strength/right handgrip strength). Cognitive tests evaluating global and specific cognitive domains were conducted at baseline and two biennial follow-ups. Generalized linear mixed models were utilized to assess the associations of abnormal handgrip strength with global cognition and multiple cognitive domain progression over time.

RESULTS

This study included 392 dementia-free participants, with an average age of 75.8 years and 179 (45.7%) males. Mild handgrip strength asymmetry was present in 88 participants (22.4%), while 53 (13.5%) exhibited moderate asymmetry. In men, the coexistence of low handgrip strength and handgrip strength asymmetry was linked to cognitive impairment over time. These associations were observed in global cognition (β^ = -1.76, 95% CI: -2.79 to -0.74), memory (immediate free recall: β^ = -0.67, 95% CI: -1.17 to -0.17), executive function (Trail Making Test-A: β^ = -0.54, 95% CI: -0.94 to -0.13), and attention (Digit span-forward: β^ = -1.00, 95% CI: -1.46 to -0.54).

CONCLUSIONS

This study found that individuals with reduced handgrip strength and handgrip strength asymmetry had an increased risk of cognitive impairment across various domains. Moreover, this association appears to be more pronounced among men than women. Incorporating these simple assessments into regular clinical practice improves the allocation of limited screening resources and timely clinical interventions in older adults.

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.

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.

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.

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.

Association Between Grip Strength and Cognitive Function in US Older Adults of NHANES 2011–2014

Background: The relationship between grip strength and cognitive function remains no consensus in the older adults. Objective: To investigate the association of grip strength with cognitive function and cognitive performance in different domains. Methods: Participants of the present cross-sectional study were from the National Health and Nutrition Examination Survey 2011-2014. Grip strength was measured by grip dynamometer, and combined handgrip strength was the sum of the largest reading from each hand. Four cognitive domains (immediate and delayed memory, language, and attention) were assessed by a set of neuropsychological tests. The subjective cognitive decline was determined via self-report. Results: Among 2,618 participants, combined grip strength was positively associated with scores on global cognitive function and each cognitive domain after controlling for demographic characteristics, lifestyle factors, and history of disease. In addition, compared to those with grip strength <  46.7 kg, participants with grip strength≥75.3 kg had odds ratios of 0.36 (95% CI: 0.21 to 0.63) for poor global cognitive function, 0.66 (95% CI: 0.38 to 1.13) for poor immediate memory, 0.53 (95% CI: 0.30 to 0.93) for poor delayed memory, 0.48 (95% CI: 0.27 to 0.86) for poor language function, 0.20 (95% CI: 0.11 to 0.35) for poor attention, and 0.36 (95% CI: 0.18 to 0.73) for subjective cognitive decline in fully adjusted model. Conclusion: Older adults with higher grip strength were significantly associated with better performance on cognition function included global and various domains such as memory, language, attention, and subjective cognitive decline.

Asymmetrical Handgrip Strength Is Associated with Lower Cognitive Performance in the Elderly

(1) Background: Several studies have reported that handgrip strength (HGS) may be a sign of lower cognitive performance. However, studies supporting an association between asymmetrical HGS and cognitive function are lacking. This study aimed to determine the association between asymmetrical HGS and cognitive performance among the elderly. (2) Methods: The study sample included 2729 individuals aged ≥60 years-old who participated in the 2011-2014 National Health and Nutrition Examination Survey. The cognitive tests consisted of the word learning and recall modules from the Consortium to Establish a Registry for Alzheimer's Disease (CERAD), Animal Fluency Test, and Digit Symbol Substitution Test (DSST). HGS was measured using a handgrip dynamometer, and asymmetrical HGS was used to calculate HGS. (3) Results: Of the 2729 participants, 53.0% were aged 60 to 69 years-old, and 47.0% were aged 70 years and older. All cognitive performance scores were significantly correlated with asymmetrical HGS in both age groups. After adjusting for confounders, there was a significant association between DSST and HGS asymmetry in both age groups. Contrastingly, a significant association was only observed for the relationship between the CERAD test and HGS asymmetry in the ≥70 year-old group. (4) Conclusions: We found that low cognitive function was associated with asymmetrical HGS in elderly participants in the United States. Thus, asymmetrical HGS may be an important predictor of cognitive deficits. However, further research is required to confirm our results and to establish possible mechanisms.

Handgrip Strength and Cognitive Function among Elderly Koreans: Insights from the Korean Longitudinal Study of Ageing

This study aims to assess handgrip strength as a predictor of cognitive decline within men and women in Korea. A random-intercept logistic regression is fit to estimate the status changes in cognitive function throughout all rounds of the KLoSA, a nationally-representative survey of adults aged 45 years and older. Males in the highest quartile were 71.9% less likely to experience cognitive impairment than those in the lowest quartile. The odds of cognitive impairment for men in the third and second quartiles reduced by 62.6% and 60.4% respectively. Similarly, the odds of cognitive impairment for women declined as 72.7%, 63.0%, and 41.8% for fourth, third, and second quartile, respectively, compared with the lowest quartile. These results imply that assessing and monitoring handgrip strength may enable us to identify subgroups of the elderly with higher likelihood of cognitive impairment in Korea.

Combined effects of handgrip strength and sensory impairment on the prevalence of cognitive impairment among older adults in Korea

Older adults commonly experience concurrent lower handgrip strength and sensory impairment. However, previous studies have analyzed the individual effects of either handgrip strength or sensory impairment on cognitive impairment. To address this gap, this study investigated the combined effects of handgrip strength and sensory impairment on cognitive impairment among older adults. In total, 2930 participants aged 65 and older were analyzed using 2014–2018 data from the Korean Longitudinal Study of Aging. Participants underwent assessments of handgrip strength (grip dynamometer), sensory impairment (self-reported responses), and cognitive impairment (Korean version of the Mini-Mental State Examination). Low handgrip strength, compared to normal handgrip strength, was associated with cognitive impairment. In participants with low handgrip strength, vision and hearing impairment were associated with cognitive impairment (odds ratio [OR] 1.36, 95% confidence interval [CI] 1.06–1.75; OR 2.58, 95% CI 1.77–3.78, respectively) compared to those with normal handgrip strength. Participants with low handgrip strength and dual sensory impairment had the highest OR for cognitive impairment (OR 3.73, 95% CI 2.65–5.25). Due to the strong association of low handgrip strength and dual sensory impairment with cognitive impairment, people living with low handgrip strength and dual sensory impairment should be classified as a high-risk group for cognitive impairment and should be prioritized for interventions.

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.

Handgrip strength and risk of cognitive outcomes: new prospective study and meta-analysis of 16 observational cohort studies

Handgrip strength (HGS), a measure of muscular strength, might be a risk indicator for cognitive functioning, but the evidence is not consistent. Using a new prospective study and meta-analysis of published observational cohort studies, we aimed to evaluate the prospective associations of HGS with poor cognitive outcomes including cognitive impairment, dementia and Alzheimer's disease (AD). Handgrip strength, measured using a Martin-Balloon-Vigorimeter, was assessed at baseline in a population-based sample of 852 men and women with good cognitive function in the Kuopio Ischemic Heart Disease cohort. Hazard ratios (HRs) with 95% confidence intervals (CIs) were estimated for cognitive outcomes. Relevant published studies were sought in MEDLINE, Embase and Web of Science from inception until October 2021 and pooled using random effects meta-analysis. During a median follow-up of 16.6 years, 229 dementia cases were recorded. Comparing extreme tertiles of HGS, the multivariable adjusted HR (95% CI) for dementia, AD and vascular dementia was 0.77 (0.55-1.07), 0.75 (0.52-1.10) and 0.49 (0.16-1.48), respectively. In a meta-analysis of 16 population-based prospective cohort studies (including the current study) comprising 180,920 participants, the pooled multivariable adjusted relative risks (95% CIs) comparing the top vs bottom thirds of HGS levels were as follows: 0.58 (0.52-0.65) for cognitive impairment; 0.37 (0.07-1.85) for cognitive decline; 0.73 (0.62-0.86) for dementia; 0.68 (0.53-0.87) for AD; and 0.48 (0.32-0.73) for vascular dementia. GRADE quality of evidence ranged from low to very low. Meta-analysis of aggregate prospective data suggests that HGS may be a risk indicator for poor cognitive outcomes such as cognitive impairment, dementia and AD. Systematic review registration: PROSPERO 2021: CRD42021237750.

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.

Association between change in handgrip strength and cognitive function in Korean adults: a longitudinal panel study

BACKGROUND

Muscular function, such as handgrip strength, has been suggested as an associated factor for cognitive impairment. This study investigated the association between temporal change in handgrip strength and cognitive function using longitudinal, nationwide data from Korean older adults.

METHODS

Our study used data from the Korean Longitudinal Study of Aging (KLoSA). The analysis covered 6696 participants who had taken the handgrip strength test and Mini-Mental State Examination (MMSE) from 2006 to 2018. We adopted general estimating equations to assess the temporal effect of handgrip strength change on cognitive function.

RESULTS

After adjusting for covariates, we observed an association between handgrip strength and low MMSE scores (β = - 0.3142 in men, β = - 0.2685 in women). Handgrip strength as a continuous variable was positively correlated with MMSE scores after adjustment (β = 0.0293 in men, β = 0.0347 in women). The group with decreased handgrip strength over time also showed greater odds for mild cognitive impairment (OR = 1.23, 95%CI = 1.05-1.27 in men, OR = 1.15, 95%CI = 1.05-1.27 in women) and dementia (OR = 1.393, 95%CI = 1.18-1.65 in men, OR = 1.19, 95%CI = 1.08-1.32 in women).

CONCLUSIONS

This study identified the relationship between handgrip strength change and cognitive function among South Korean adults. According to our large, longitudinal sample, decreasing handgrip strength was associated with decline in cognitive function.

Higher Handgrip Strength Is Linked to Better Cognitive Performance in Chinese Adults with Hypertension

Objective: There is growing evidence that in adults, higher levels of handgrip strength (HGS) are linked to better cognitive performance. However, the relationship between HGS and cognitive performance has not been sufficiently investigated in special cohorts, such as individuals with hypertension who have an intrinsically higher risk of cognitive decline. Thus, the purpose of this study was to examine the relationship between HGS and cognitive performance in adults with hypertension using data from the Global Ageing and Adult Health Survey (SAGE). Methods: A total of 4486 Chinese adults with hypertension from the SAGE were included in this study. Absolute handgrip strength (aHGS in kilograms) was measured using a handheld electronic dynamometer, and cognitive performance was assessed in the domains of short-term memory, delayed memory, and language ability. Multiple linear regression models were fitted to examine the association between relative handgrip strength (rHGS; aHGS divided by body mass index) and measures of cognitive performance. Results: Overall, higher levels of rHGS were associated with higher scores in short-term memory (β = 0.20) and language (β = 0.63) compared with the lowest tertiles of rHGS. In male participants, higher HGS was associated with higher scores in short-term memory (β = 0.31), language (β = 0.64), and delayed memory (β = 0.22). There were no associations between rHGS and cognitive performance measures in females. Conclusion: We observed that a higher level of rHGS was associated with better cognitive performance among hypertensive male individuals. Further studies are needed to investigate the neurobiological mechanisms, including sex-specific differences driving the relationship between measures of HGS and cognitive performance in individuals with hypertension.

A Narrative Review of Handgrip Strength and Cognitive Functioning: Bringing a New Characteristic to Muscle Memory

BACKGROUND

Measures of handgrip strength have not only emerged as a clinically viable screening tool for determining risk for morbidity, functional disability, and early mortality, but also for helping to identify cognitive deficits. However, the phenomena that links low handgrip strength with cognitive decline remains unclear. The role of the muscular and neural systems, and their adaptations to muscle strengthening activities over the life course, may provide important information for how age-related changes to muscle mass, strength, and neural capacity influence cognition. Moreover, disentangling how handgrip strength and cognitive function are associated may help to inform healthcare providers working with aging adults and guide targeted interventions aiming to preserve muscle and cognitive functioning.

OBJECTIVE

To 1) highlight and summarize evidence examining the associations of handgrip strength and cognitive functioning, and 2) provide directions for future research in this area.

METHODS

Articles from the PubMed database were searched from November 2018-May 2019. The search term algorithm, inclusion and exclusion criteria were pre-specified by investigators.

RESULTS

Several cross-sectional and longitudinal studies have revealed that measures of handgrip strength were associated with cognitive declines regardless of age demographics and the presence of comorbidities.

CONCLUSION

Handgrip strength can be used in clinical and epidemiological settings for helping to determine the onset and progression of cognitive impairment. Future research should continue to examine how handgrip strength and cognitive function are linked.

Examining the effects of multiple chronic conditions on cognitive decline and potential moderators among older Koreans: Findings from the Korean Longitudinal Study of Ageing 2006-2016

BACKGROUND

More than half of older Koreans have two or more chronic conditions, known as multiple chronic conditions (MCC). Successful self-management (e.g., diet control, exercise, taking medications) is critical to prevent worsening of condition or acquisition of additional chronic conditions. This study investigated the effects of MCC on cognitive decline and risk factors in each chronic condition group over a 10-year period.

METHODS

Six waves (2006-2016) of the Korean Longitudinal Study of Ageing were used, featuring 2,198 older adults who were cognitively healthy at baseline. MCC were categorized into three groups: no chronic condition (n=831), one chronic condition (n=813), and two or more chronic conditions (n=554). Linear mixed-effects model analyses were conducted using SAS 9.4.

RESULTS

Individuals with MCC showed greater cognitive decline than those with no or one chronic condition. Different factors were associated with cognition in each group. Among those with no chronic condition, age, income, education, and functional limitation were associated with cognitive decline. Among those with one chronic condition, age, marital status, working status, self-rated health, and arthritis were associated with cognitive decline. Among those with two or more chronic conditions, age, income, marital status, and living arrangement were associated with cognitive decline. Listed factors have p-values less than .05.

CONCLUSIONS

Findings indicate MCC is significantly related with cognitive decline. Risk factors for cognitive decline differed across three chronic condition groups. Self-management programs that target each group can be a promising strategy to mitigate cognitive decline among older Koreans.

Grip Strength and the Risk of Cognitive Decline and Dementia: A Systematic Review and Meta-Analysis of Longitudinal Cohort Studies

Purpose: Loss of grip strength and cognitive impairment are prevalent in the elderly, and they may share the pathogenesis in common. Several original studies have investigated the association between them, but the results remained controversial. In this systematic review and meta-analysis, we aimed to quantitatively determine the relationship between baseline grip strength and the risk of cognitive impairment and provide evidence for clinical work.

Methods: We performed a systematic review using PubMed, EMBASE, Cochrane, and Web of Science up to March 23, 2020, and focused on the association between baseline grip strength and onset of cognitive impairment. Next, we conducted a meta-analysis using a hazard ratio (HR) and 95% confidence interval (CI) as effect measures. Heterogeneity between the studies was examined using I² and p-value. Sensitivity analyses and subgroup analyses were also performed, and publication bias was assessed by Begg's and Egger's tests.

Results: Fifteen studies were included in this systematic review. After sensitivity analyses, poorer grip strength was associated with more risk of cognitive decline and dementia (HR = 1.99, 95%CI: 1.71–2.32; HR = 1.54, 95%CI: 1.32–1.79, respectively). Furthermore, subgroup analysis indicated that people with poorer strength had more risk of Alzheimer's disease (AD) and non-AD dementia (HR = 1.41, 95%CI: 1.09–1.81; HR = 1.45, 95%CI: 1.10–1.91, respectively).

Conclusions: Lower grip strength is associated with more risk of onset of cognitive decline and dementia despite of subtype of dementia. We should be alert for the individuals with poor grip strength and identify cognitive dysfunction early.

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.

Associations of Handgrip Strength and Handgrip Strength Asymmetry With Depression in the Elderly in Korea: A Cross-sectional Study

Objectives

Recent studies have suggested that assessing handgrip strength (HGS) asymmetry together with HGS may be helpful for evaluating problems in geriatric patients. This study aimed to identify whether HGS asymmetry, weakness, or both were associated with depression in Korean older adults.

Methods

This study included 4274 subjects from the sixth and seventh Korea National Health and Nutrition Examination Survey. Depression was measured using the Patient Health Questionnaire-9. The maximum HGS of the dominant hand was used as a representative value. HGS symmetry was categorized by the ratio of the HGS of the dominant hand to that of non-dominant hand. The odds ratio (OR) for depression was calculated according to the HGS and its symmetry.

Results

In total, 240 (12.5%) men and 534 (22.7%) women had depression. HGS or HGS asymmetry showed no statistically significant associations with depression in elderly men. Elevated odds of depression were observed in elderly women with low HGS (OR, 1.93; 95% confidence interval [CI], 1.33 to 2.81) or prominent HGS asymmetry (OR, 1.46; 95% CI, 1.02 to 2.08). There was a positive additive interaction between asymmetric HGS and weakness, as women with low and prominently asymmetric HGS showed higher odds of depression (OR, 3.77; 95% CI, 2.16 to 6.59) than women with high and symmetric HGS.

Conclusions

Depression in elderly Korean women was associated with both low and asymmetric HGS. Our findings support the potential value of HGS asymmetry as an indicator of HGS.

Productive Activities and Risk of Cognitive Impairment and Depression: Does the Association Vary by Gender?

We examine how labor together with social participation protects against cognitive impairment and depression, with a focus on gender differences. Data are drawn from four waves of the Korean Longitudinal Study of Aging (2006-2012). Both paid work and unpaid work are considered labor participation. Social participation includes the frequency of participation in formal social institutions, religious groups, grandparenting, and interactions with family and friends. Using growth curve models, we find that social and labor participation are independently associated with outcomes and effects vary by gender. Religious group activity was beneficial only for women, whereas inability to work was detrimental for men only. Informal social gatherings and labor participation, paid or unpaid, were beneficial for both genders. Findings on gender differences highlight how social identities can shape social roles and confine activity space, and productive engagement, affecting outcomes for mental health in later life.

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.

What are the association patterns between handgrip strength and adverse health conditions? A topical review

Measures of handgrip strength can be used to conveniently assess overall muscle strength capacity. Although stand-alone measures of handgrip strength provide robust health information, the clinical meaningfulness to determine prevention and treatment options for weakness remains limited because the etiology of muscle weakness remains unclear. Moreover, clinical outcomes associated with handgrip strength are wide-ranging. Therefore, disentangling how handgrip strength is associated with health conditions that are metabolically or neurologically driven may improve our understanding of the factors linked to handgrip strength. The purpose of this topical review was to highlight and summarize evidence examining the associations of handgrip strength with certain health outcomes that are metabolically and neurologically driven. From this perusal of the literature, we posit that stand-alone handgrip strength be considered an umbrella assessment of the body systems that contribute to strength capacity, and a panoptic measurement of muscle strength that is representative of overall health status, not a specific health condition. Recommendations for future strength capacity–related research are also provided.