Quadriceps strength and executive functions in older women

The association between isometric strength and cognitive function in adults with cerebral palsy

Background

The literature supports quantifying the maximum force/tension generated by one's forearm muscles such as the hand grip strength (HGS) to screen for physical and cognitive frailty in older adults. Thus, we postulate that individuals with cerebral palsy (CP), who are at higher risk for premature aging, could benefit from tools that objectively measure muscle strength as a functional biomarker to detect frailty and cognitive decline. This study assesses the clinical relevancy of the former and quantifies isometric muscle strength to determine its association with cognitive function in adults with CP.

Methods

Ambulatory adults with CP were identified from a patient registry and were enrolled into this study. Peak rate of force development (RFD) and maximum voluntary isometric contraction of the quadriceps were measured using a commercial isokinetic machine, while HGS was collected with a clinical dynamometer. Dominant and non-dominant side were identified. Standardized cognitive assessments, including the Wechsler Memory and Adult Intelligence Scales IV, Short Test of Mental Status, and the Patient-Reported Outcomes Measurement Information System (PROMIS®) were used to evaluate cognitive function.

Results

A total of 57 participants (32 females; mean age 24.3 [SD 5.3]; GMFCS levels I-IV) were included in the analysis. Although dominant and non-dominant RFD and HGS measures were associated with cognitive function, non-dominant peak RFD showed the strongest associations with cognitive function.

Conclusion

RFD capacity may reflect age-related neural and physical health and could be a better health indicator than HGS in the CP population.

Bidirectional association between executive and physical functions among older adults: A systematic review

OBJECTIVE

We aimed to examine the bidirectional associations between specific executive function (EF) and physical function (PF) subdomains among older adults.

METHODS

A systematic literature search (MEDLINE, EMBASE, PsycINFO, EBSCOHOST, Scopus and EmCare) was undertaken from February 2018 to May 2020. Observational studies measuring associations between EF and PF subdomains among older adults were included.

RESULTS

Twenty-nine studies met the inclusion criteria. Twenty-seven studies reported associations between EF and PF. There were bidirectional associations between slower processing speed and slower gait speed; slower processing speed and lower muscle strength; and lower verbal fluency and slower gait speed. Lower muscle strength was unilaterally associated with lower working memory.

CONCLUSIONS

We found consistent bidirectional associations between processing speed with gait speed and muscle strength, and verbal fluency and gait speed. There was a unidirectional association between muscle strength and working memory. Common causal mechanisms for EF and PF require further studies.

Metabolic regulation of aging and age-related disease

Inquiry into relationships between energy metabolism and brain function requires a uniquely interdisciplinary mindset, and implementation of anti-aging lifestyle strategies based on this work also involves consistent mental and physical discipline. Dr. Mark P. Mattson embodies both of these qualities, based on the breadth and depth of his work on neurobiological responses to energetic stress, and on his own diligent practice of regular exercise and caloric restriction. Dr. Mattson created a neurotrophic niche in his own laboratory, allowing trainees to grow their skills, form new connections, and eventually migrate, forming their own labs while remaining part of the extended lab family. In this historical review, we highlight Dr. Mattson's many contributions to understanding neurobiological responses to physical exercise and dietary restriction, with an emphasis on the mechanisms that may underlie neuroprotection in ageing and age-related disease. On the occasion of Dr. Mattson's retirement from the National Institute on Aging, we highlight his foundational work on metabolism and neuroplasticity by reviewing the context for these findings and considering their impact on future research on the neuroscience of aging.

Independent and combined associations of cardiorespiratory fitness and muscle strength with metabolic syndrome in older adults: A cross-sectional study

BACKGROUND

Studies have shown that low cardiorespiratory fitness (CRF) and low muscle strength are independently associated with metabolic syndrome (MetS) in older adults. This study investigated the isolated and combined associations of low CRF and muscle strength with MetS in older adults.

METHODS

This cross-sectional study included 184 older adults (71% women; aged 65.6 ± 4.3 years) without a prior history of cardiovascular disease. CRF and muscle strength were assessed by the six-minute walking test and 30-s chair stand test, respectively. Results below the 25th percentile of the cohort were used to define low CRF and low muscle strength. MetS was defined according to NCEP-ATP III criteria. Poisson's regression with robust variance was used to determine the prevalence ratio (PR) for MetS. Reference group was composed by older adults with both CRF and muscle strength above 25th percentile.

RESULTS

Prevalence of low CRF, low muscle strength, and combined low CRF and muscle strength was 22.8%, 17.9%, and 10.9%, respectively. The prevalence of MetS was 56.5% in the full cohort. Isolated low CRF (PR 1.05, 95% CI 0.73 to 1.52; p = 0.793) and muscle strength (PR 1.09, 95% CI 0.74 to 1.61; p = 0.651) were not associated with MetS in the adjusted analysis. Combined low CRF and muscle strength was associated with MetS (PR 1.45, 95% CI 1.09 to 1.93; p = 0.011).

CONCLUSIONS

Older adults with combined, but not isolated, low CRF and muscle strength showed an increased risk for MetS.

Rate of Muscle Contraction Is Associated With Cognition in Women, Not in Men

BACKGROUND

In older persons, lower hand grip strength is associated with poorer cognition. Little is known about how the rate of muscle contraction relates to cognition and upper extremity motor function, and sex differences are understudied.

METHODS

Linear regression, adjusting for age, race, education, body mass index, appendicular lean mass, and knee pain, assessed sex-specific cross-sectional associations of peak torque, rate of torque development (RTD), and rate of velocity development (RVD) with cognition and upper extremity motor function.

RESULTS

In men (n = 447), higher rate-adjusted peak torque and a greater RVD were associated with faster simple finger tapping speed, and a greater RVD was associated with higher nondominant pegboard performance. In women (n = 447), higher peak torque was not associated with any measures, but a greater RTD was associated with faster simple tapping speed and higher language performance, and a greater RVD was associated with higher executive function, attention, memory, and nondominant pegboard performance. In women with low isokinetic peak torque, RVD was associated with attention and memory.

CONCLUSIONS

RVD capacity may reflect neural health, especially in women with low muscle strength.

Sarcopenic obesity and cognitive performance

BACKGROUND

Sarcopenia and obesity both negatively impact health including cognitive function. Their coexistence, however, can pose an even higher threat likely surpassing their individual effects. We assessed the relationship of sarcopenic obesity with performance on global- and subdomain-specific tests of cognition.

PATIENTS AND METHODS

The study was a cross-sectional analysis of data from a series of community-based aging and memory studies. The sample consisted of a total of 353 participants with an average age of 69 years with a clinic visit and valid cognitive (eg, Montreal Cognitive Assessment, animal naming), functional (eg, grip strength, chair stands), and body composition (eg, muscle mass, body mass index, percent body fat) measurements.

RESULTS

Sarcopenic obesity was associated with the lowest performance on global cognition (Est.Definition1=-2.85±1.38, p=0.039), followed by sarcopenia (Est.Definition1=-1.88±0.79, p=0.017) and obesity (Est.Definition1=-1.10±0.81, p=0.175) adjusted for sociodemographic factors. The latter, however, did not differ significantly from the comparison group consisting of older adults with neither sarcopenia nor obesity. Subdomain-specific analyses revealed executive function (Est.Definition1=-1.22±0.46 for sarcopenic obesity; Est.Definition1=-0.76±0.26 for sarcopenia; Est.Definition1=-0.52±0.27 for obesity all at p<0.05) and orientation (Est.Definition1=0.59±0.26 for sarcopenic obesity; Est.Definition1=-0.36±0.15 for sarcopenia; Est.Definition1=-0.29±0.15 all but obesity significant at p<0.05) as the individual cognitive skills likely to be impacted. Potential age-specific and depression effects are discussed.

CONCLUSION

Sarcopenia alone and in combination with sarcopenic obesity can be used in clinical practice as indicators of probable cognitive impairment. At-risk older adults may benefit from programs addressing loss of cognitive function by maintaining/improving strength and preventing obesity.

Associations between physical function, dual-task performance and cognition in patients with mild Alzheimer's disease

OBJECTIVE

Alzheimer's disease (AD) causes a gradual decline in cognition, limitations of dual-tasking and physical function leading to total dependence. Hence, information about the interaction between physical function, dual-task performance and cognition may lead to new treatment strategies with the purpose of preserving function and quality of life. The objective of this study was to investigate the associations between physical function, dual-task performance and cognition in community-dwelling patients with mild AD.

METHODS

Baseline results from 185 participants (50-90 years old) in the single blinded multicenter RCT 'ADEX' (Alzheimer's disease: the effect of physical exercise) were used. Assessments included tests of physical function: 400-m walk test, 10-m walk test, Timed Up and Go test and 30-s chair stand test; dual-task performance, i.e., 10-m walk while counting backwards from 50 or naming the months backwards; and cognition, i.e., Mini Mental State Examination, Symbol Digit Modalities Test, the Stroop Color and Word Test, and Lexical verbal fluency test.

RESULTS

Results in the 30-s chair stand test correlated significantly with all tests of cognition (r = .208-.242) while the other physical function tests only randomly correlated with tests of cognition. Results in the dual-task counting backwards correlated significantly with results in all tests of cognition (r = .259-.388), which accounted for 7%-15% of the variation indicating that a faster time to complete dual-task performance was associated with better cognitive performance.

CONCLUSION

The evidence of the associations between physical function, dual-task performance and cognition is important when creating new rehabilitation interventions to patients with mild AD.

Physical performance is associated with working memory in older people with mild to severe cognitive impairment

BACKGROUND

Physical performances and cognition are positively related in cognitively healthy people. The aim of this study was to examine whether physical performances are related to specific cognitive functioning in older people with mild to severe cognitive impairment.

METHODS

This cross-sectional study included 134 people with a mild to severe cognitive impairment (mean age 82 years). Multiple linear regression was performed, after controlling for covariates and the level of global cognition, with the performances on mobility, strength, aerobic fitness, and balance as predictors and working memory and episodic memory as dependent variables.

RESULTS

The full models explain 49-57% of the variance in working memory and 40-43% of episodic memory. Strength, aerobic fitness, and balance are significantly associated with working memory, explaining 3-7% of its variance, irrespective of the severity of the cognitive impairment. Physical performance is not related to episodic memory in older people with mild to severe cognitive impairment.

CONCLUSIONS

Physical performance is associated with working memory in older people with cognitive impairment. Future studies should investigate whether physical exercise for increased physical performance can improve cognitive functioning. This trial is registered with ClinicalTrials.gov NTR1482.

Avaliacao neuropsicologica de idosos praticantes de capoeira

INTRODUÇÃO: Este estudo procura contribuir com uma relação pouco explorada no meio acadêmico: capoeira, cognição e envelhecimento. Relacionando estudos sobre funções executivas e a capoeira, busca-se investigar a interligação desta arte e as funções executivas. Estas se referem a desempenhos de comportamentos complexos (memória de trabalho, flexibilidade mental, tomada de decisão) e a memória léxico-semântica. OBJETIVO: Comparar o desempenho de funções executivas em idosas praticantes de capoeira e idosas não praticantes de exercício físico. MÉTODO: Estudo transversal que coletou as informações de cada participante apenas uma vez. Serão comparados dois grupos: 1) grupo de idosos praticantes de capoeira e 2) idosos que não fazem exercício físico. Para seleção e caracterização dos grupos utilizaram-se: questionário sociodemográfico, aspectos gerais de saúde e escala de hábitos de leitura e escrita, mini-exame de estado mental (MEEM) e escala de depressão de Yesavage (GDS-30). Para avaliar o desempenho das funções executivas foi realizado o teste de trilhas e as tarefas de fluência verbal. Para análise estatística dos dados será utilizado o teste de Shapiro-Wilk para normatização dos dados. O teste de t de Student e o teste U de Mann Whitney serão usados para comparar duas médias de amostras independentes. Utilizou-se a improvisação, a ação, a tomada de decisão, o equilíbrio e as noções de espaço, tempo, ritmo, música, e a compreensão do jogo da capoeira como intervenção devido à possível utilização dos processos executivos nessa arte. RESULTADOS: Verificou-se que não houve diferença significativa nos testes realizados. Porém houve superioridade nos testes de fluência verbal e testes de trilha A e B, sendo maior em B no grupo de capoeira do que no grupo controle. CONCLUSÃO: A prática de capoeira tem uma tendência em contribuir para a melhora das funções executivas, embora os mecanismos desse benefício não estejam claros

Combination of the clock drawing test with the physical phenotype of frailty for the prediction of mortality and other adverse outcomes in older community dwellers without dementia

BACKGROUND

Cognitive assessment is thought to increase the ability of the physical phenotype of frailty to identify older persons at a higher risk for adverse outcomes.

OBJECTIVE

Data from a cohort of dementia-free community dwellers were used to investigate whether the clock drawing test (CDT), a quick and easy cognitive screening test, is associated with adverse health outcomes independently of the physical phenotype of frailty.

METHODS

This was a prospective population-based cohort study of 766 dementia-free Italian community dwellers aged 65 years or older. Baseline assessment included the physical phenotype of frailty, 3 different CDT protocols [Sunderland, Shulman, and the clock drawing interpretation scale (CDIS)], and several health confounders. Hazard ratios (HR) and odds ratio (OR) along with their corresponding 95% confidence intervals (CI) from models adjusted for frailty and sociodemographic and health confounders were used to estimate the independent association of the CDT with the 7-year risk of all-cause mortality and the 3-year risk of new and worsening disability, hospitalization, and fractures.

RESULTS

After adjustment for confounders, the Sunderland CDT was significantly associated with all-cause mortality independently of the physical phenotype of frailty (HR = 1.44, 95% CI 1.03-2.01, p = 0.031). However, compared to all nonfrail participants with a normal Sunderland CDT, the HR was 1.57 (95% CI 1.09-2.26, p = 0.016) for those with impairment on the Sunderland CDT only, 2.48 (95% CI 1.46-4.20, p = 0.001) for those with frailty only, and 2.52 (95% CI 1.34-4.77, p = 0.004) for those with both frailty and impairment on the Sunderland CDT. Mortality was unrelated to the CDIS CDT (p = 0.359) and the Shulman CDT (p = 0.281). No statistically significant relationship was found between nonlethal outcomes and any CDT protocol, although trends were found for an association of both the Sunderland CDT (p = 0.118) and the CDIS CDT with worsening disability (p = 0.154).

CONCLUSIONS

In older persons, depending on the scoring system, the CDT may predict the mortality risk independently of the physical phenotype of frailty. However, combining the two measurements does not improve their individual prognostic abilities.

Physical predictors of cognitive performance in healthy older adults: a cross-sectional analysis

There is ample evidence that physical and cognitive performance are related, but the results of studies investigating this relationship show great variability. Both physical performance and cognitive performance are constructs consisting of several subdomains, but it is presently unknown if the relationship between physical and cognitive performance depends on subdomain of either construct and whether gender and age moderate this relationship. The aim of this study is to identify the strongest physical predictors of cognitive performance, to determine the specificity of these predictors for various cognitive subdomains, and to examine gender and age as potential moderators of the relationship between physical and cognitive performance in a sample of community-dwelling older adults. In total, 98 men and 122 women (average age 74.0±5.6 years) were subjected to a series of performance-based physical fitness and neuropsychological tests. Muscle strength, balance, functional reach, and walking ability (combined score of walking speed and endurance) were considered to predict cognitive performance across several domains (i.e. memory, verbal attention, visual attention, set-shifting, visuo-motor attention, inhibition and intelligence). Results showed that muscle strength was a significant predictor of cognitive performance for men and women. Walking ability and balance were significant predictors of cognitive performance for men, whereas only walking ability was significant for women. We did not find a moderating effect of age, nor did we find support for a differential effect of the physical predictors across different cognitive subdomains. In summary, our results showed a significant relationship between cognitive and physical performance, with a moderating effect of gender.

Effectiveness of exercise on cognitive impairment and Alzheimer's disease

Physical activity has a protective effect on brain function in older people. Here, we briefly reviewed the studies and results related to the effects of exercise on cognitive impairment and Alzheimer's disease. The main findings from the current body of literature indicate positive evidence for structured physical activity (cardiorespiratory and resistance exercise) as a promising non-pharmacological intervention for preventing cognitive decline. More studies are needed to determine the mechanisms involved in this preventative effect, including on strength, cardiorespiratory, and other types of exercise. Thus, the prevention of Alzheimer's disease may depend on healthy lifestyle habits, such as a structured physical fitness program.

Knee extensor strength is associated with Mini-Mental State Examination scores in elderly men

The present study examined whether the strength capability of knee extensor muscles is associated with global cognitive function, assessed by Mini-Mental State Examination (MMSE), in non-disabled elderly men. Isometric torques during maximal voluntary knee extension, plantar flexion, and elbow flexion and MMSE scores were determined in 39 non-disabled men aged 61-79 years and used for the cross-sectional analysis examining the associations among the measured variables. Moreover, 27 of the subjects participated in a training program consisted of body mass-based exercises (sitting down onto and standing up from a chair, hip joint extension and flexion, calf raises, side leg raises, and trunk flexion and extension) 6 days a week for 3 months. Isometric torques and MMSE scores were determined after the intervention. Among the data before intervention, only knee extension torque (KET) and KET relative to body mass (KET/BM) significantly correlated to the MMSE scores: r = 0.579 (P < 0.0001) for KET and r = 0.520 (P < 0.001) for KET/BM. After the intervention, KET and KET/BM increased significantly, but MMSE score did not. However, the absolute change in MMSE scores was significantly associated with that in KET (r = 0.381, P < 0.05) and KET/BM (r = 0.422, P < 0.05). These findings indicate that the strength capability of knee extensors is associated with global cognitive function in non-disabled elderly men, and provide a new perspective to a general concept that exercises strengthening knee extensor muscles should be included in resistance training programs for elderly individuals.

Association between executive function and physical performance in older Korean adults: findings from the Korean Longitudinal Study on Health and Aging (KLoSHA)

Reduced executive function and physical performance are common age-related conditions. This study evaluated the associations between executive function and physical performance in a representative sample of older adults. Cross-sectional data were analyzed from a population-based sample of 629 men and women aged 65 or older and living in one typical city in Korea. Specific aspects of executive function were assessed using the trail making test, digit span test, and lexical fluency test to measure set shifting, working memory and cognitive flexibility functions. Physical performance was measured using performance-oriented mobility assessment (POMA) scores and isokinetic muscle strength. Subjects' self-efficacy was also assessed using the activities-specific balance confidence (ABC) scale. Results of the lexical fluency test were associated with POMA scores and muscle strength, independent of age, gender, education, comorbidity, physical activity status, depression, and global cognition, suggesting that reduced cognitive flexibility is associated with reduced physical performance and muscle strength. Self-efficacy was also independently associated with physical performance and muscle strength. Clinicians need to consider the association between executive function and physical performance when working to improve physical functioning in an aged population.