Sarcopenia Is Associated with Cognitive Impairment in Older Adults: A Systematic Review and Meta-Analysis

Association of sarcopenia with regional brain atrophy and white matter lesions in a general older population: the Hisayama Study

Sarcopenia has been reported to be associated with cognitive decline and the risk of dementia. However, few studies have addressed the association between sarcopenia and brain morphological changes in the general population. A total of 1373 community-dwelling participants aged ≥ 65 years underwent brain MRI. Sarcopenia was defined based on the Asian Working Group for Sarcopenia's criteria. The pattern of regional gray matter volume loss associated with sarcopenia were assessed using a voxel-based morphometry (VBM) analysis. Regional brain volumes, intracranial volumes (ICV), and white matter lesions volumes (WMLV) were also measured using FreeSurfer. An analysis of covariance was used to examine the associations of sarcopenia with regional brain volumes in proportion to ICV. Of the participants, 112 had sarcopenia. The participants with sarcopenia had significantly lower total brain volume/ICV and total gray matter volume/ICV and higher WMLV/ICV than those without sarcopenia after adjusting for confounders. In VBM, sarcopenia was associated with lower gray matter volume in the frontal lobe, insula, cingulate gyrus, hippocampus, amygdala, and basal ganglia. Using FreeSurfer, we confirmed that the participants with sarcopenia had significantly lower frontal, insular, cingulate, and hippocampal volumes than those without sarcopenia. The current study showed that participants with sarcopenia had significantly lower volume in the frontal lobe, insula, cingulate, and hippocampus and higher WMLV than participants without sarcopenia. As these brain regions are likely to play an important role in cognitive function, these changes may suggest a shared underlying mechanism for the progression of sarcopenia and cognitive decline.

Association of the sarcopenia index with cognitive impairment in a middle-aged to older patients with acute ischemic stroke or transient ischemic attack: A multicenter cohort study

OBJECTIVES

The sarcopenia (SI) index, defined as the serum creatinine to cystatin C ratio, is considered a predictor of poor muscle health and malnutrition, which is related to major adverse cardiovascular events. However, the effect of the SI index on cognitive function in stroke patients remains unknown. In this study, we aimed to examine the association between the SI and longitudinal cognitive impairment in patients with acute ischemic stroke or transient ischemic attack.

RESEARCH DESIGN AND METHODS

Participants who met the inclusion criteria in this national, multicenter, prospective cohort study were enrolled from the Impairment of Cognition and Sleep (ICONS) study of the China National Stroke Registry-3 (CNSR-3). They were categorized into four groups according to the quartile of the SI index. Cognitive function was assessed using the Montreal Cognitive Assessment (MoCA) scale. Multivariable-adjusted logistic regression models were performed to evaluate the association between the SI index and post-stroke cognitive impairment (PSCI) at the 3-month follow-up. Moreover, discrimination tests were used to evaluate the incremental predictive value of the SI index beyond the potential risk factors. Furthermore, we performed subgroup analyses to test interactions.

RESULTS

Among the enrolled participants, the lower the SI index was, the worse the cognitive performance. At the 3-month follow-up, participants in the lowest SI quartile group exhibited a 42% increase in the risk of cognitive impairment relative to the highest quartile group [OR 0.58 (95% CI 0.37-0.90)]. Moreover, after applying the discrimination test, adding the SI index into the potential risk factors resulted in a slight improvement in predicting the risk of cognitive impairment [NRI 14% (P = 0.01)].

CONCLUSION

This study demonstrated that a lower sarcopenia index was positively associated with a higher prevalence of PSCI. Monitoring the SI index in stroke patients and early identification and treatment of individuals with low SI level may be helpful to reduce the risk of cognitive impairment.

SuperAgers and centenarians, dynamics of healthy ageing with cognitive resilience

Graceful healthy ageing and extended longevity is the most desired goal for human race. The process of ageing is inevitable and has a profound impact on the gradual deterioration of our physiology and health since it triggers the onset of many chronic conditions like dementia, osteoporosis, diabetes, arthritis, cancer, and cardiovascular disease. However, some people who lived/live more than 100 years called 'Centenarians" and how do they achieve their extended lifespans are not completely understood. Studying these unknown factors of longevity is important not only to establish a longer human lifespan but also to manage and treat people with shortened lifespans suffering from age-related morbidities. Furthermore, older adults who maintain strong cognitive function are referred to as "SuperAgers" and may be resistant to risk factors linked to cognitive decline. Investigating the mechanisms underlying their cognitive resilience may contribute to the development of therapeutic strategies that support the preservation of cognitive function as people age. The key to a long, physically, and cognitively healthy life has been a mystery to scientists for ages. Developments in the medical sciences helps us to a better understanding of human physiological function and greater access to medical care has led us to an increase in life expectancy. Moreover, inheriting favorable genetic traits and adopting a healthy lifestyle play pivotal roles in promoting longer and healthier lives. Engaging in regular physical activity, maintaining a balanced diet, and avoiding harmful habits such as smoking contribute to overall well-being. The synergy between positive lifestyle choices, access to education, socio-economic factors, environmental determinants and genetic supremacy enhances the potential for a longer and healthier life. Our article aims to examine the factors associated with healthy ageing, particularly focusing on cognitive health in centenarians. We will also be discussing different aspects of ageing including genomic instability, metabolic burden, oxidative stress and inflammation, mitochondrial dysfunction, cellular senescence, immunosenescence, and sarcopenia.

Appendicular lean mass and the risk of stroke and Alzheimer's disease: a mendelian randomization study

BACKGROUND

Appendicular lean mass (ALM) is a good predictive biomarker for sarcopenia. And previous studies have reported the association between ALM and stroke or Alzheimer's disease (AD), however, the causal relationship is still unclear, The purpose of this study was to evaluate whether genetically predicted ALM is causally associated with the risk of stroke and AD by performing Mendelian randomization (MR) analyses.

METHODS

A two-sample MR study was designed. Genetic variants associated with the ALM were obtained from a large genome-wide association study (GWAS) and utilized as instrumental variables (IVs). Summary-level data for stroke and AD were generated from the corresponding GWASs. We used random-effect inverse-variance weighted (IVW) as the main method for estimating causal effects, complemented by several sensitivity analyses, including the weighted median, MR-Egger, and MR-pleiotropy residual sum and outlier (MR-PRESSO) methods. Multivariable analysis was further conducted to adjust for confounding factors, including body mass index (BMI), type 2 diabetes mellitus (T2DM), low density lipoprotein-C (LDL-C), and atrial fibrillation (AF).

RESULTS

The present MR study indicated significant inverse associations of genetically predicted ALM with any ischemic stroke ([AIS], odds ratio [OR], 0.93; 95% confidence interval [CI], 0.89-0.97; P = 0.002) and AD (OR, 090; 95% CI 0.85-0.96; P = 0.001). Regarding the subtypes of AIS, genetically predicted ALM was related to the risk of large artery stroke ([LAS], OR, 0.86; 95% CI 0.77-0.95; P = 0.005) and small vessel stroke ([SVS], OR, 0.80; 95% CI 0.73-0.89; P < 0.001). Regarding multivariable MR analysis, ALM retained the stable effect on AIS when adjusting for BMI, LDL-C, and AF, while a suggestive association was observed after adjusting for T2DM. And the estimated effect of ALM on LAS was significant after adjustment for BMI and AF, while a suggestive association was found after adjusting for T2DM and LDL-C. Besides, the estimated effects of ALM were still significant on SVS and AD after adjustment for BMI, T2DM, LDL-C, and AF.

CONCLUSIONS

The two-sample MR analysis indicated that genetically predicted ALM was negatively related to AIS and AD. And the subgroup analysis of AIS revealed a negative causal effect of genetically predicted ALM on LAS or SVS. Future studies are required to further investigate the underlying mechanisms.

Sarcopenia Among Older People in the Philippines: A Scoping Review

Aims: This review aimed to identify and map the evidence about sarcopenia among older Filipinos. Methods: Studies about sarcopenia among Filipinos aged 60 and above were included. All studies regardless of type, setting, language, and timeframe were reviewed. The Cochrane Library, Cumulative Index of Nursing and Allied Health, Embase, PubMed, and Health Research and Development Information Network were searched. The study was conducted per an a priori protocol and utilized the Joanna Briggs Institute guidance for scoping reviews. Results: From the 87 records identified, 20 studies published from 2013 to 2023 were eligible (≥ 5424 participants). The studies were varied; 11 cross-sectional, 2 conference lectures, 2 consensus reports, 1 meta-analysis, cohort study, case series, posthoc analysis, and continuing education. As to setting, 11 studies were conducted in the hospital and 4 in the community. On the level of prevention, 5 studies addressed the primary level, 10 studies secondary, and 2 studies both tertiary and secondary. The studies focused on: sarcopenia in a specific group (13 studies), consensus (4 studies), and education (3 studies). Conclusions: Sarcopenia studies among older Filipinos were limited. Most were hospital-based and involved patients with comorbidities. Some studies used sarcopenia assessment guidelines with Filipino normative references. Sarcopenia impacts the overall well-being of older Filipinos; hence more studies and health promotion programs are necessary.

Kidney function and other associated factors of sarcopenia in community-dwelling older adults: The SCOPE study

AIM

Sarcopenia is associated with several factors and medical conditions among older adults, though previous research has shown limitations and inconsistencies, especially regarding chronic kidney disease (CKD). We investigated the clinical and laboratory variables associated with sarcopenia and severe sarcopenia in older adults, focusing on kidney function measures.

METHODS

Data from community-dwelling adults aged ≥75 years participating in the SCOPE multicenter prospective cohort study were assessed cross-sectionally. Comprehensive geriatric assessment was conducted; sociodemographic and lifestyle factors, clinical variables and comorbidities, anthropometric and bioelectrical impedance analysis, blood and urine laboratory variables were collected. EWGSOP2 revised criteria were used to define sarcopenia and its severity. Estimated glomerular filtration rate (eGFR) was calculated using creatinine and non-creatinine-based equations, and CKD stages were defined accordingly.

RESULTS

1420 participants were included, prevalence of sarcopenia was 10.6 %, and 6 % had severe sarcopenia. Multivariate logistic regression analysis showed that age [OR =1.14; 95 %CI (1.09-1.19)], body mass index (BMI) [0.83 (0.79-0.88)], disability performing instrumental activities of daily living (IADL) [2.61 (1.69-4.06)], Mini Mental State Examination (MMSE) score <24 [2.75 (1.62-4.67)], osteoporosis [2.39 (1.55-3.67)], and stage 4 CKD defined by CKD-EPIBTP-B2M, a non-creatinine-based eGFR equation [2.88 (1.11-7.49)], were independently associated with sarcopenia; as were specifically with severe sarcopenia, with more pronounced associations.

CONCLUSIONS

In community-dwelling older adults, sarcopenia is a relevant condition and is associated with severe CKD, older age, IADL, cognitive impairments, osteoporosis and low BMI. These factors should be assessed for proper identification and management of older patients with sarcopenia, and even more so with severe sarcopenia.

Multidomain interventions for sarcopenia and cognitive flexibility in older adults for promoting healthy aging: a systematic review and meta-analysis of randomized controlled trials

The global population is undergoing rapid aging, making physical activity a crucial element in preventing mortality and lowering the risk of Alzheimer's disease. Age-related declines in muscle mass and cognitive abilities significantly contribute to frailty and dependency. Thus, this study focuses on a meticulous analysis of the protective effects of multidomain interventions, an emerging resource combating age-related declines. It seeks to underscore their profound impact on cognitive flexibility and sarcopenia, highlighting their pivotal role in mitigating the adverse effects of aging. To identify relevant randomized controlled trials up to November 2023, we reviewed eight online academic databases, following PERSiST guidelines, PRISMA reporting system, and PICOs criteria. Meta-analyses on selected functional outcomes utilized a random-effects model, including the Timed Up and Go Test, Sit to Stand Test, Victoria Stroop Test, and Trail Making Test. Out of 2082 scrutinized articles, 17 were included in the systematic review, and 8 in the meta-analysis. Positive effects (p = 0.05, I2 = 57%; 95% CI - 0.63 to - 0.05) were observed in cognitive flexibility for certain interventions. Similarly, interventions addressing muscle strength demonstrated improvements in the Sit to Stand Test for the exercise group compared to the control group (p = 0.02, I2 = 0%; 95% CI - 0.63 to - 0.05). These findings underscore the importance of incorporating physical activity as a primary component of public health interventions for promoting healthy aging and reducing the burden of age-related diseases. Future interventions may explore more homogeneous approaches and evaluate the impact of thrice multidomain weekly sessions.

Association between Serum GDF-15 and Cognitive Dysfunction in Hemodialysis Patients

Cognitive dysfunction is more frequent in end-stage renal disease (ESRD) patients undergoing hemodialysis compared with the healthy population, emphasizing the need for early detection. Interest in serum markers that reflect cognitive function has recently increased. Elevated serum growth differentiation factor 15 (GDF-15) levels are known to be associated with an increased risk of decreased renal function and cognitive dysfunction. This study investigated the relationship between GDF-15 and cognitive dysfunction in hemodialysis patients using a retrospective analysis of 92 individuals aged ≥ 18 years. Cognitive function was assessed using the Korean version of the Mini-Mental Status Examination (K-MMSE), categorizing patients into normal (≥24 points) and cognitive dysfunction (<24 points). As a result, serum GDF-15 concentrations were at significantly higher levels in the cognitive dysfunction group (7500.42 pg/mL, p = 0.001). Logistic regression indicated an increased risk of K-MMSE scores < 24 points when serum GDF-15 exceeded 5408.33 pg/mL. After indoxyl sulfate exposure in HT22 cells, HT22 cells survival was decreased and GDF-15 expression in HT22 cells was increased. Similarly, exposure to indoxyl sulfate in mouse brain tissue resulted in an increased expression of GDF-15. This study highlights the potential of serum GDF-15 as a marker for cognitive dysfunction in hemodialysis patients, offering a valuable screening tool. Serum GDF-15 is related to cognitive dysfunction in hemodialysis patients and may be helpful in screening for cognitive dysfunction in hemodialysis patients.

Sarcopenia and diabetes-induced dementia risk

This study aimed to investigate whether sarcopenia independently increases the risk of diabetes-induced dementia in elderly individuals diagnosed with type 2 diabetes mellitus. The study cohort consisted of a large sample of elderly individuals aged 60 years and above, who were diagnosed with type 2 diabetes mellitus between 2008 and 2018. To minimize potential bias and achieve covariate balance between the sarcopenia and non-sarcopenia groups, we employed propensity score matching. Various statistical analyses, including Cox regression models to assess dementia risk and associations, competing risk analysis to account for mortality and Poisson regression analysis for incidence rates, were used. Before propensity score matching, the study included 406 573 elderly type 2 diabetes mellitus patients, with 20 674 in the sarcopenia group. Following propensity score matching, the analysis included a total of 41 294 individuals, with 20 647 in the sarcopenia group and 20 647 in the non-sarcopenia group. Prior to propensity score matching, elderly type 2 diabetes mellitus patients with sarcopenia exhibited a significantly higher risk of dementia (adjusted hazard ratio: 1.12, 95% confidence interval: 1.07-1.17). After propensity score matching, the risk remained significant (adjusted hazard ratio: 1.14, 95% confidence interval: 1.07-1.21). Incidence rates of dementia were notably higher in the sarcopenia group both before and after propensity score matching, underscoring the importance of sarcopenia as an independent risk factor. Our study highlights sarcopenia as an independent risk factor for diabetes-induced dementia in elderly type 2 diabetes mellitus patients. Advanced age, female gender, lower income levels, rural residency, higher adapted diabetes complication severity index and Charlson Comorbidity Index scores and various comorbidities were associated with increased dementia risk. Notably, the use of statins was linked to a reduced risk of dementia. This research underscores the need to identify and address modifiable risk factors for dementia in elderly type 2 diabetes mellitus patients, offering valuable insights for targeted interventions and healthcare policies.

The Association between Kidney Function Biomarkers and Delayed Memory Impairments among Older Adults in the European North of Russia

The prevention of memory decline requires better knowledge of biological markers. We studied the associations between kidney function biomarkers and memory decline (assessed with the Mini-Mental State Examination-MMSE) in elderly individuals without dementia (MMSE 24-30, age 60-74 years, n = 643, Arkhangelsk, Russia). Participants were divided by sex and into three groups according to the delayed memory performance: recall of 0-1, 2, and 3 out of 3 words. The median of serum creatinine was 82 μmol/L in men who recalled 2 words and both medians in those recalling 3 and 0-1 words were 87 μmol/L. The 90th percentile for creatinine in men recalling 0-1 words (115.0 μmol/L) exceeded the upper limit of the normal range (110.5 μmol/L), while those who recalled 3 and 2 words had 90th percentiles within the normal range (109 and 101 μmol/L, respectively). Glomerular filtration rates were normal (≥60 mL/min/1.73 m2) with a median of 92.0 mL/min/1.73 m2 in men who recalled 2 words, 84.4 and 84.9 mL/min/1.73 m2 in men who recalled 3 and 0-1 words, respectively. None of these associations were observed in women. A reduced serum creatinine in older non-demented men may indicate the initial stages of memory decline, while the increased creatinine may reflect further stages of memory impairment.

Association between body mass index and cognitive impairment in Chinese older adults

Background

The association between body mass index (BMI) and the risk of cognitive impairment remains uncertain. Relatively few studies have analyzed the dose-response relationship between BMI and cognitive impairment. This article utilized nationally representative longitudinal data to assess the association between BMI and cognitive impairment in Chinese older adults.

Objective

The present study aimed to analyze the association between BMI and cognitive impairment in Chinese older people, including an investigation of gender differences and the dose-response relationship.

Methods

Data were obtained from the China Health and Retirement Longitudinal Study database in 2015 and 2018. The present study used logistic regression to analyze the relationship between baseline BMI and cognitive impairment, and adopted a restricted cubic spline model to plot dose-response curves for baseline BMI and prevalence of risk of cognitive impairment.

Results

The mean BMI of the survey population was 23.48 ± 3.66 kg/m2, and the detection rate of cognitive impairment was 34.2%. Compared to the normal weight group (18.5 ≤ BMI < 23.9 kg/m2), the odds ratio (OR) for cognitive impairment was 1.473 (95% CI: 1.189-1.823) in the underweight group (BMI < 18.5 kg/m2), whereas the corresponding OR was 0.874 (95% CI: 0.776-0.985) for the overweight or obese group (BMI ≥ 24.0 kg/m2) after adjusting for confounders. Gender subgroup analysis showed that overweight or obese older women were less likely to develop cognitive impairment (OR = 0.843; 95% CI: 0.720-0.987). The results of the restricted cubic spline analysis revealed a curvilinear L-shaped relationship between BMI and the risk of cognitive impairment (P non-linearity <0.05). In particular, the risk of cognitive impairment was higher at a lower baseline BMI. In contrast, BMI in the range of 23.2-27.8 kg/m2 was associated with a decreased risk of cognitive impairment.

Conclusion

BMI is a dose-dependent related factor for cognitive impairment in Chinese older adults. Being underweight is a risk factor for the development of cognitive impairment, while being overweight or obese is less likely to have cognitive impairment, particularly in female older people. Keeping BMI ranging from 23.2-27.8 kg/m2 in older adults can help maintain cognitive function.

Muscle-Brain crosstalk in cognitive impairment

Sarcopenia is an age-related, involuntary loss of skeletal muscle mass and strength. Alzheimer's disease (AD) is the most common cause of dementia in elderly adults. To date, no effective cures for sarcopenia and AD are available. Physical and cognitive impairments are two major causes of disability in the elderly population, which severely decrease their quality of life and increase their economic burden. Clinically, sarcopenia is strongly associated with AD. However, the underlying factors for this association remain unknown. Mechanistic studies on muscle-brain crosstalk during cognitive impairment might shed light on new insights and novel therapeutic approaches for combating cognitive decline and AD. In this review, we summarize the latest studies emphasizing the association between sarcopenia and cognitive impairment. The underlying mechanisms involved in muscle-brain crosstalk and the potential implications of such crosstalk are discussed. Finally, future directions for drug development to improve age-related cognitive impairment and AD-related cognitive dysfunction are also explored.

Myokines as mediators of exercise-induced cognitive changes in older adults: protocol for a comprehensive living systematic review and meta-analysis

Background

The world's population is aging, but life expectancy has risen more than healthy life expectancy (HALE). With respect to brain and cognition, the prevalence of neurodegenerative disorders increases with age, affecting health and quality of life, and imposing significant healthcare costs. Although the effects of physical exercise on cognition in advanced age have been widely explored, in-depth fundamental knowledge of the underlying mechanisms of the exercise-induced cognitive improvements is lacking. Recent research suggests that myokines, factors released into the blood circulation by contracting skeletal muscle, may play a role in mediating the beneficial effect of exercise on cognition. Our goal in this ongoing (living) review is to continuously map the rapidly accumulating knowledge on pathways between acute or chronic exercise-induced myokines and cognitive domains enhanced by exercise.

Method

Randomized controlled studies will be systematically collected at baseline and every 6 months for at least 5 years. Literature search will be performed online in PubMed, EMBASE, PsycINFO, Web of Science, SportDiscus, LILACS, IBECS, CINAHL, SCOPUS, ICTRP, and ClinicalTrials.gov. Risk of bias will be assessed using the Revised Cochrane Risk of Bias tool (ROB 2). A random effects meta-analysis with mediation analysis using meta-analytic structural equation modeling (MASEM) will be performed. The primary research question is to what extent exercise-induced myokines serve as mediators of cognitive function. Secondarily, the pooled effect size of specific exercise characteristics (e.g., mode of exercise) or specific older adults' populations (e.g., cognitively impaired) on the relationship between exercise, myokines, and cognition will be assessed. The review protocol was registered in PROSPERO (CRD42023416996).

Discussion

Understanding the triad relationship between exercise, myokines and cognition will expand the knowledge on multiple integrated network systems communicating between skeletal muscles and other organs such as the brain, thus mediating the beneficial effects of exercise on health and performance. It may also have practical implications, e.g., if a certain myokine is found to be a mediator between exercise and cognition, the optimal exercise characteristics for inducing this myokine can be prescribed. The living review is expected to improve our state of knowledge and refine exercise regimes for enhancing cognitive functioning in diverse older adults' populations.

Registration

Systematic review and meta-analysis protocol was registered with the International Prospective Register of Systematic Reviews (PROSPERO) on the 24th of April 2023 (registration number CRD42023416996).

Cognitive Impairment Predicts Sarcopenia 9 Years Later Among Older Adults

OBJECTIVE

To assess the longitudinal association between cognitive impairment and sarcopenia in a sample of Brazilian community-dwelling older adults.

DESIGN

Nine-year observational prospective study.

SETTING AND PARTICIPANTS

A total of 521 community-dwelling older adults from 2 Brazilian sites of the Frailty in Brazilian Older Adults (FIBRA in Portuguese) study.

METHODS

Sarcopenia was defined as low hand-grip strength and low muscle mass. Cognitive impairment was determined at baseline using the Mini-Mental State Examination, with education-adjusted cutoff scores. The logistic regression model was used to assess the association between cognitive impairment and incident sarcopenia after adjusting for gender, age, education, morbidities, physical activity, and body mass index. Inverse probability weighting was applied to correct for sample loss at follow-up.

RESULTS

The mean age of the study population was 72.7 (±5.6) years, and 365 were women (70.1%). Being 80 years and older (odds ratio [OR], 4.62; 95% CI, 1.38-15.48; P = .013), being under- and overweight (OR, 0.29; 95% CI, 0.11-0.76; P = .012, and OR, 5.12; 95% CI, 2.18-12.01; P < .001, respectively) and having cognitive impairment (OR, 2.44; 95% CI, 1.18-5.04; P = .016) at baseline predicted sarcopenia after 9 years.

CONCLUSION AND IMPLICATIONS

Cognitive impairment may predict sarcopenia in Brazilian older adults. More studies are necessary to identify the main mechanisms shared by sarcopenia and cognitive decline, which could support the development of prevention interventions.

Functional brain changes in sarcopenia: evidence for differential central neural mechanisms in dynapenic older women

BACKGROUND

The European Working Group on Sarcopenia in Older People (EWGSOP2) recently revised its definition and diagnostic criteria for sarcopenia, placing muscle strength at the forefront. The pathogenesis of dynapenia (or low muscle strength) is still not fully understood, but there is emerging evidence that central neural factors constitute critical determinants.

METHODS

Our cross-sectional study included 59 community-dwelling older women (mean age 73.1 ± 4.9 years). Participants underwent detailed skeletal muscle assessments for muscle strength defined by handgrip strength and chair rise time measurements using the recently published EWGSOP2 cut-off points. Functional magnetic resonance imaging (fMRI) was assessed during the performance of a cognitive dual-task paradigm, consisting of a baseline, two single-tasks (motor and arithmetic) and one dual-task (motor and arithmetic combined).

RESULTS

Forty-seven percent (28/59) of participants were classified as dynapenic. fMRI results revealed a differential recruitment of motor circuits in the brain during the dual-task condition in dynapenic as compared with non-dynapenic participants. In particular, while the brain activity during the single-tasks did not differ between the two groups, only during the dual-task non-dynapenic participants showed significant increased activation in dorsolateral prefrontal and premotor cortex, and in supplementary motor area as compared to dynapenic participants.

CONCLUSION

Our results point to a dysfunctional involvement of brain networks associated with motor control in dynapenia in a multi-tasking paradigm. A better knowledge of the link between dynapenia and brain functions could provide new impulses in the diagnosis and interventions for sarcopenia.

Age- and sex-specific associations between sarcopenia severity and poor cognitive function among community-dwelling older adults in Japan: The IRIDE Cohort Study

Introduction

This study examined whether the association between sarcopenia severity and cognitive function differed according to sex and age in community-dwelling older adults in Japan.

Methods

This is a cross-sectional study of older adults (age ≥ 65 years) consisting of five regional cohorts integrated as the Integrated Research Initiative for Living Well with Dementia (IRIDE) Cohort Study. Sarcopenia severity was determined based on the Asian Working Group for Sarcopenia 2019, which assessed grip strength, walking speed, and skeletal muscle mass index. Poor cognitive function was defined as a Mini-Mental State Examination score of ≤ 23. Odds ratios (ORs) and 95% confidence intervals (CIs) for poor cognitive function were calculated by sex and age group (65–74 and ≥75 years) using binomial logistic regression models, which were adjusted for age, educational attainment, history of non-communicable diseases, smoking and drinking habits, living alone, frequency of going outdoors, exercise habits, and depressive symptom.

Results

Of the 8,180 participants, 6,426 (1,157 men aged 65–74 and 1,063 men aged 75 or older; 2,281 women aged 65–74 and 1,925 women aged 75 or older) were analyzed. The prevalence ratio of sarcopenia and severe sarcopenia were 309 (13.9%) and 92 (4.1%) among men and 559 (13.3%) and 166 (3.7%) among women, respectively. A total of 127 (5.8%) men and 161 (3.9%) women had a poor cognitive function. Setting non-sarcopenia as a reference, the adjusted ORs (95% CI) of poor cognitive function were 2.20 (1.54, 3.15) for sarcopenia and 3.56 (2.20, 5.71) for severe sarcopenia. A similar trend was observed in analyses stratified by sex and age, with linear associations (P for trend &lt;0.05) in both categories. Furthermore, there was a significant interaction (P &lt; 0.05) between sex and sarcopenia severity, indicating a stronger linear association of sarcopenia severity with poor cognitive function in women compared with men.

Discussion and conclusion

Sarcopenia severity was linearly associated with poor cognitive function in adults aged ≥ 65 years, with a stronger association in women compared with men.

Body fat and components of sarcopenia relate to inflammation, brain volume and neurometabolism in older adults

Obesity and sarcopenia are associated with cognitive impairments at older age. Current research suggests that blood biomarkers may mediate this body-brain crosstalk, altering neurometabolism and brain structure eventually resulting in cognitive performance changes. Seventy-four older adults (60-85 years old) underwent bio-impedance body composition analysis, handgrip strength measurements, 8-Foot Up-and-Go (8UG) test, Montreal Cognitive Assessment (MoCA), blood analysis of interleukin-6 (IL-6), kynurenine, and insulin-like growth factor-1 (IGF-1), as well as brain magnetic resonance imaging (MRI) and proton magnetic resonance spectroscopy (¹H-MRS), estimating neurodegeneration and neuroinflammation. Normal fat% or overweight was associated with larger total gray matter volume compared to underweight or obesity in older adults and obesity was associated with higher N-acetylaspartate/Creatine levels in the sensorimotor and dorsolateral prefrontal cortex. Muscle strength, not muscle mass/physical performance, corresponded to lower kynurenine and higher N-acetylaspartate/Creatine levels in the dorsal posterior cingulate and dorsolateral prefrontal cortex. The inflammatory and neurotrophic blood biomarkers did not significantly mediate these body-brain associations. This study used a multimodal approach to comprehensively assess the proposed mechanism of body-brain crosstalk.

A systematic review and meta-analysis of the prevalence and correlation of mild cognitive impairment in sarcopenia

Sarcopenia is a progressive skeletal muscle disorder involving the loss of muscle mass and function, associated with an increased risk of disability and frailty. Though its prevalence in dementia has been studied, its occurrence in mild cognitive impairment (MCI) has not been well established. As MCI is often a prelude to dementia, our study aims to investigate the prevalence of MCI among individuals with sarcopenia and to also ascertain whether sarcopenia is independently associated with MCI. The Cochrane Library, PubMed, Ovid, Embase and Web of Science were systematically searched for articles on MCI and/or sarcopenia published from inception to 1 February 2022. We reviewed the available literature on the number of individuals with MCI and/or sarcopenia and calculated odds ratios (ORs) of sarcopenia in MCI and MCI in sarcopenia, respectively. Statistical analyses were performed using the meta package in Stata, Version 12.0. A total of 13 studies and 27 428 patients were included in our analysis. The pooled prevalence of MCI in participants with sarcopenia was 20.5% (95% confidence interval [CI]: 0.140-0.269) in a total sample of 2923 cases with a high level of heterogeneity (P < 0.001; I²  = 95.4%). The overall prevalence of sarcopenia with MCI was 9.1% (95% CI: 0.047-0.134, P < 0.001; I²  = 93.0%). For overall ORs, there were 23 364 subjects with a mean age of 73 years; the overall adjusted OR between MCI and sarcopenia was 1.46 (95% CI: 1.31-1.62). Slight heterogeneity in both adjusted ORs (P = 0.46; I²  = 0%) was noted across the studies. The prevalence of MCI is relatively high in patients with sarcopenia, and sarcopenia may be a risk factor for MCI.

Association of Sarcopenia and Its Defining Components with the Degree of Cognitive Impairment in a Memory Clinic Population

BACKGROUND

Sarcopenia and cognitive impairment are two leading causes of disabilities.

OBJECTIVE

The objective was to examine the prevalence of sarcopenia and investigate the association between sarcopenia diagnostic components (muscle strength, muscle mass, and physical performance) and cognitive impairment in memory clinic patients.

METHODS

368 patients were included (age 59.0±7.25 years, women: 58.7%), displaying three clinical phenotypes of cognitive impairments, i.e., subjective cognitive impairment (SCI, 57%), mild cognitive impairment (MCI, 26%), and Alzheimer's disease (AD, 17%). Sarcopenia was defined according to diagnostic algorithm recommended by the European Working Group on Sarcopenia in Older People. Components of sarcopenia were grip strength, bioelectrical impedance analysis, and gait speed. They were further aggregated into a score (0-3 points) by counting the numbers of limited components. Multi-nominal logistic regression was applied.

RESULTS

Probable sarcopenia (i.e., reduced grip strength) was observed in 9.6% of the patients, and 3.5% were diagnosed with sarcopenia. Patients with faster gait speed showed less likelihood of MCI (odds ratio [OR]: 0.24, 95% confidence interval [CI]: 0.06-0.90) and AD (OR: 0.12, 95% CI: 0.03-0.60). One or more limited sarcopenia components was associated with worse cognitive function. After adjusting for potential confounders, the association remained significant only for AD (OR 4.29, 95% CI 1.45-11.92).

CONCLUSION

The results indicate a connection between the sarcopenia components and cognitive impairments. Limitations in the sarcopenia measures, especially slow walking speed, were related to poorer cognitive outcomes. More investigationsare required to further verify the causal relationship between sarcopenia and cognitive outcomes.

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.

Prescription of resistance training for sarcopenic older adults: Does it require specific attention?

Sarcopenia is an age-related neuromuscular disease characterized by substantial muscle atrophy, dynapenia and/or loss of physical function. Sarcopenia progression increases the risk for numerous negative events, including falls, disability, hospitalization, nursing home placement, and death. As such, this condition is recognized as an important topic in gerontology and geriatrics. The best approach to counteract the development and progression of sarcopenia is actively debated. Resistance training (RT) has received special attention in this context, owing to the large number of studies showing its ability to produce significant improvements in sarcopenia-related parameters. Recommendations to guide RT prescription for older adults with different conditions, including people who have traits of sarcopenia, have been published. Some authors have argued that RT guidelines for older adults are similar to one another, which may indicate that the presence of sarcopenia does not require specific physical exercise programs. However, older people with sarcopenia might present with peculiar physical, biomechanical, physiological, and psychosocial characteristics that, in our view, are not taken into adequate consideration in existing exercise guidelines. Here, we present evidence to support the view that RT prescription for older adults with sarcopenia is complex, multifactorial, and still needs more evidence.

Serum creatinine to cystatin C ratio and cognitive function among middle-aged and older adults in China

Background

The sarcopenia index (SI, serum creatinine/serum cystatin C × 100) is recently suggested to be a reliable marker for sarcopenia. It has been reported that sarcopenia is associated with poorer cognition. The purpose of this study was to evaluate the correlation between SI and cognitive function among middle-aged and older adults from the China Health and Retirement Longitudinal Study (CHARLS).

Materials and methods

A total of 6,442 participants ≥45 years of age were enrolled in this study from CHARLS between 2011 and 2012. Cognitive function was assessed by interview-based measurements, including orientation and attention, episodic memory, visuo-construction, and the total cognitive function. SI was calculated by serum creatinine (mg/dL)/cystatin C (mg/L) × 100. One-way analysis of variance (ANOVA) was used to compare the differences among groups divided according to SI quartiles by gender. Both linear and logistic regression models were applied to investigate the relationship between SI and cognitive function.

Results

After adjustment for potential confounders, we found SI was significantly and positively correlated with total cognitive function scores both in males and females [β = 0.014, 95% confidence interval (CI) 0.007 to 0.021, P < 0.001; β = 0.011, 95 CI% 0.003 to 0.018, P = 0.004; respectively]. Similarly, when the total cognitive function score was treated as a categorical variable according to quartiles in males and females, higher SI was related to better total cognitive function scores in both males and females [odds ratio (OR) = 1.147, 95% CI 1.028 to 1.279, P = 0.014; OR = 1.219, 95% CI 1.106 to 1.344, P < 0.001; respectively] following adjustment for confounders.

Conclusions

Lower sarcopenia index was correlated with a higher prevalence of cognitive impairment among middle-aged and older adults in China.

Comparison of Rapid Cognitive Screen against Montreal Cognitive Assessment in screening for cognitive impairment in the old and old-old

BACKGROUND

The Montreal Cognitive Assessment (MoCA) was developed as a screening tool for mild cognitive impairment (MCI). Given the need for a rapid screening test in settings such as primary care, we compare the validity of the Rapid Cognitive Screen (RCS) against the MoCA, and determine cut-off scores in the old and old-old.

METHODS

Cross-sectional study involving community-dwelling 'old' (65 to 79 years old) and 'old-old' (≥ 80 years old) without dementia. Cognitive impairment was defined by MoCA score 17 to 22. Validation was done using the receiver operating characteristic (ROC) curve analysis: area under the curve (AUC), sensitivity (Sn), and specificity (Sp).

RESULTS

Of the 183 participants (mean age 72.1 ± 5.2 years),15.8% (n = 29) were classified as cognitively impaired. The overall ROC curve had an AUC of 0.82 (95% CI 0.75-0.90, P < 0.01) with an optimal cut-off of 7/8 on RCS (Sn 0.77, Sp 0.72). The 'old' and 'old-old' group had AUC of 0.82 (95% CI 0.74-0.91, P < 0.01) with 8/9 as optimal cut-off (Sn 0.51, Sp 0.96) and AUC of 0.85 (95% CI 0.66-1.03, P < 0.01) with 7/8 as optimal cut-off (Sn 0.71, Sp 1.00) respectively. In multivariate analysis, age was associated with 0.05 (95% CI -0.10-0.00, P < 0.04) point decrement, while >6 years of education was associated with 0.82 (95% CI 0.32-1.33, P < 0.01) point increment in RCS scores.

CONCLUSION

The three-item RCS is quick and easy to administer. Although RCS met the criterion for good validity against MoCA in predicting cognitive impairment, its utility as a first-line screening tool needs to be further validated in a large-scale population study.

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.

Longitudinal Association between Sarcopenia and Cognitive Impairment among Older Adults in Rural Malaysia

Sarcopenia is a condition that is highly prevalent among older adults. This condition is linked to numerous adverse health outcomes, including cognitive impairment that impairs healthy ageing. While sarcopenia and cognitive impairment may share a common pathway, limited longitudinal studies exist to show the relationship between these two conditions. Therefore, this study aimed to examine the longitudinal association between sarcopenia and cognitive impairment. This is a cohort study among older adults residing in Kuala Pilah District, Negeri Sembilan, Malaysia. There were 2404 respondents at the baseline and 1946 respondents at one-year follow-up. Cognitive impairment was determined using Mini-mental State Examination scores. Sarcopenia was identified using the Asian Working Group for Sarcopenia 2019 criteria, gait speed was measured using a 4-meter gait test, handgrip strength was assessed using Jamar handheld dynamometer, and appendicular skeletal muscle mass was measured using bioelectrical impedance analysis. Generalized estimating equation (GEE) was used to determine the longitudinal association between sarcopenia and cognitive impairment, presented as relative risk (RR) and its 95% confidence interval. The prevalence of sarcopenia was 5.0% (95% CI 4.00–5.90), and severe sarcopenia was 3.60% (95% CI 2.84–4.31). Upon adjusting for covariates, older adults with sarcopenia have an 80 per cent increased risk of cognitive impairment compared to those without (RR 1.80; 95% CI 1.18–2.75). Similarly, severe sarcopenia was found to significantly increase the risk of cognitive impairment by 101 per cent in the adjusted model (RR 2.01; 95% CI 1.24–3.27). Our study showed that sarcopenia, severe sarcopenia, low physical activity, depressive symptoms, hearing impairment and chronic pain were associated with a higher risk of cognitive impairment among community-dwelling older adults. Therefore, early intervention to prevent sarcopenia, depressive symptoms, hearing impairment, chronic pain, and higher physical activity among older adults is recommended.

Sarcopenic Obesity Tendency and Nutritional Status Is Related to the Risk of Sarcopenia, Frailty, Depression and Quality of Life in Patients with Dementia

The purpose of this study was to investigate the nutritional status of dementia patients and examine the correlation with sarcopenia, frailty, depression, and quality of life. We enrolled patients aged 60 years and over with Mini Mental State Examination (MMSE) scores ≤ 26 (Taiwan), and dementia diagnosed by a neurologist or psychiatrist. Nutritional status was assessed with the Mini Nutritional Assessment (MNA). Muscle mass was measured by dual-energy X-ray absorptiometry. Muscle strength and endurance were evaluated by handgrip, leg-back strength, dumbbell curls, sit to stand test, and gait speed. Quality of life, frailty, and depression status were measured by questionnaires. Patients with moderate dementia (MMSE ≤ 20) had a significantly lower MNA score, muscle function, and quality of life than patients with mild dementia (p < 0.01). A lower MNA score was significantly associated with the risk of frailty (odds ratio: 4.76, p < 0.01), depression (odds ratio: 3.17, p = 0.03), and poor quality of life (odds ratio: 2.73, p < 0.05), and sarcopenia (odds ratio: 3.97, p = 0.03) after adjusting for potential confounders. In conclusion, patients with dementia were at risk of malnutrition, and nutritional status was associated to the risk of sarcopenia, frailty, depression, and quality of life.

Importance of TP53 codon 72 and intron 3 duplication 16 bp polymorphisms and their haplotypes in susceptibility to sarcopenia in Iranian older adults

Background

Sarcopenia is described as age-related progressive skeletal muscle failure that results in marked reduction in the patient’s independence and life quality. In this study, we explored the association of TP53 exon 4 Arg72pro (rs1042522) and Intron 3 16-bp Del/Ins (rs17878362) polymorphisms and their haplotypes with sarcopenia, anthropometric, body composition and biochemical parameters.

Methods

A total of 254 older individuals (65 sarcopenic and 189 healthy) were recruited in this research and genotyped by PCR–RFLP. Linear regression was applied to find the correlation between TP53 polymorphism, and biochemical and anthropometric parameters. The correlation between TP53 polymorphism and haplotypes and the risk of sarcopenia was investigated by logistic regression.

Results

Arg/Pro genotype carriers was at a lower (ORadj = 0.175, 95% CI = 0.068 – 0.447; P < 0.001) risk of sarcopenia compared to the Arg/Arg group. In haplotypes analysis, Arg-Ins (ORadj: 0.484, 95% CI = 0.231 – 1.011, P = 0.043) and Pro-Ins (ORadj: 0.473, 95% CI = 0.210 – 1.068, P = 0.022) haplotypes showed decreased risk of developing sarcopenia. Moreover, in the case of codon 72 polymorphism, skeletal muscle mass, appendicular lean mass (ALM), skeletal muscle mass index (SMI), hand grip strength and Triglycerides, for Intron 3 16-bp Del/Ins polymorphism, albumin, calcium, cholesterol, and LDL were different, and for the haplotypes, skeletal muscle mass, SMI, ALM, HDL and triglycerides were significantly different between groups.

Conclusions

We suggested that the Arg/Pro genotype of the codon 72 polymorphism in exon 4 of TP53, and Arginine-Insertion and Proline-Insertion haplotypes might decrease the risk of sarcopenia in Iranian older adults.

Low lean mass and cognitive performance: data from the National Health and Nutrition Examination Surveys

BACKGROUND

Low lean mass and cognitive impairment are both age-related diseases. In addition, these conditions share many risk factors. However, the association between them has been controversial in recent years.

OBJECTIVE

To investigate the association between low lean mass and cognitive performance in U.S. adults using NHANES data from 1999 to 2002.

METHODS

A total of 2550 participants were identified in the National Health and Nutrition Examination Survey Database (1999-2002). The independent variable was low lean mass, and the dependent variable was cognitive performance. Men and women were classified as having low lean mass if appendicular lean mass (ALM) adjusted for BMI (ALM_BMI) was < 0.789 and < 0.512, respectively. Cognitive performance was assessed using the Digit Symbol Substitution Test (DSST). Higher scores on the DSST indicated better cognitive performance. The covariates included sex, age, race, poverty income ratio, comorbidity index, educational level, physical activity and smoking status.

RESULTS

For the primary outcome, our multivariate linear regression analysis indicated that participants without low lean mass were associated with better cognitive performance (β = 1.50; 95% CI [0.12-2.89]). Subgroup analysis results indicated that the association was similar in sex, age, race, poverty income ratio, comorbidity index, educational level, physical activity and smoking status.

CONCLUSIONS

Participants without low lean mass were associated with better cognitive performance. We might be able to improve cognitive performance by treating low lean mass, thus providing an opportunity for intervention at a younger age.

How does the skeletal muscle communicate with the brain in health and disease?

Endocrine mechanisms have been largely associated with metabolic control and tissue cross talk in mammals. Classically, myokines comprise a class of signaling proteins released in the bloodstream by the skeletal muscle, which mediate physiological and metabolic responses in several tissues, including the brain. Recent exciting evidence suggests that myokines (e.g. cathepsin B, FNDC5/irisin, interleukin-6) act to control brain functions, including learning, memory, and mood, and may mediate the beneficial actions of physical exercise in the brain. However, the intricate mechanisms connecting peripherally released molecules to brain function are not fully understood. Accumulating findings further indicates that impaired skeletal muscle homeostasis impacts brain metabolism and physiology. Here we review recent findings that suggest that muscle-borne signals are essential for brain physiology and discuss perspectives on how these signals vary in response to exercise or muscle diseases. Understanding the complex interactions between skeletal muscle and brain may result in more effective therapeutic strategies to expand healthspan and to prevent brain disease.

An association analysis between hypertension, dementia, and depression and the phases of pre-sarcopenia to sarcopenia: A cross-sectional analysis

Sarcopenia is intricately related to aging associated diseases, such as neuropsychiatric disorders, oral status, and chronic diseases. Dementia and depression are interconnected and also related to sarcopenia. The preliminary shift from robust to sarcopenia (i.e., pre-sarcopenia) is an important albeit underdiscussed stage and is the focus of this study. Identifying factors associated with pre-sarcopenia may lead to sarcopenia prevention. To separately examine the effects of dementia and depression on pre-sarcopenia/sarcopenia, we conducted multiple analyses. This cross-sectional study used health checkup data from a rural Japanese island. The participants were aged 60 years and above, and the data included muscle mass, gait speed, handgrip strength, oral status (teeth and denture), chronic diseases (e.g., hypertension), dementia (cognitive assessment for dementia, iPad Version), and depression (self-rating depression scale). A total of 753 older adult participants were divided into the sarcopenia (n = 30), pre-sarcopenia (n = 125), and robust (n = 598) groups. An ordered logit regression analysis indicated that age and depression were positively correlated with sarcopenia, while hypertension was negatively associated with it. A multiple logistic regression analysis between the robust and pre-sarcopenia groups showed significant associations between the same three variables. Depression was associated with pre-sarcopenia, but not dementia. There was also a significant association between hypertension and pre-sarcopenia. Further research is needed to reveal whether the management of these factors can prevent sarcopenia.

Three definitions of probable sarcopenia and associations with falls and functional disability among community-dwelling older adults

OBJECTIVES

To assess the prevalence of probable sarcopenia according to 3 different definitions ("strength, assistance with walking, rise from a chair, climb stairs, falls"- SARC-F score, low grip strength, and the guidelines indicated by the European Working Group on Sarcopenia in Older People 2 - EWGSOP2) and assess the association of probable sarcopenia with functional disability and falls among community-dwelling older adults.

METHODS

Cross-sectional study with 419 older adults. Probable sarcopenia was assessed by 3 definitions: a SARC-F ≥ 4, low grip strength (< 27 kg for men and < 16 kg for women), and the EWGSOP2 criteria. Associations were investigated using Pearson's chi-square test and prevalence ratios were estimated by Poisson regression (P < 0.05).

RESULTS

Of the total, probable sarcopenia was identified in 23.0% of participants (SARC-F ≥ 4 score), 33.7% (low grip strength), and 10.4% (EWGSOP2) according to each different definition. In adjusted regression models, having at least 1 instrumental activities of daily living (IADL) disability and having fallen in the last 12 months were significantly associated with a SARC-F ≥ 4 (prevalence ratio, PR = 1.60; and PR = 2.50, respectively) and EWGSOP2 (PR = 1.78; and PR = 2.19, respectively).

CONCLUSIONS

IADL disability and falls were associated with a SARC-F ≥ 4 and the EWGSOP2 criteria (SARC-F ≥ 4 and low grip strength). Probable sarcopenia may be used in clinical practice in order to facilitate the diagnosis of definite sarcopenia and to implement early interventions that could prevent functional decline and falls in older people.

Relationships between sarcopenia, depressive symptoms, and mild cognitive impairment in Chinese community-dwelling older adults

BACKGROUND

Mild cognitive impairment (MCI) represents an intermediate state between normal cognitive aging and dementia. We aimed to investigate the association and mediation pathways of sarcopenia, including its individual components (muscle mass, muscle strength, and physical performance), and depressive symptoms with MCI in the older adults.

METHODS

This study consisting of 1394 community-dwelling Chinese older adults aged 60 years and older in Tianjin and Shanghai, China. Sarcopenia was defined according to the Asian Working Group for Sarcopenia (AWGS) criteria. Depressive symptoms were evaluated by the 30-item Geriatric Depression Scale (GDS). Cognitive function was assessed by Mini-Mental State Examination (MMSE), the Chinese version of the Dementia Rating Scale (CDRS) was used to apply the diagnostic of non-dementia, and instrument activities of daily living (IADL) were used to evaluate daily living activities. Logistic regression and mediation analyses fully adjusted for all potential confounding factors were conducted.

RESULTS

Sarcopenia, handgrip strength, gait speed, and depressive symptoms were associated with MCI. Furthermore, depressive symptoms significantly mediated the association of sarcopenia, handgrip strength, and gait speed with cognitive function. The relationship of depressive symptoms and cognition were also mediated by sarcopenia, handgrip strength, and gait speed.

LIMITATIONS

This is a cross-sectional study.

CONCLUSIONS

Our findings suggest that sarcopenia may contribute substantially to the development of MCI in the older adults via depressive symptoms, although the reverse may also be true. These findings may help guide clinicians to better diagnose and manage MCI in the context of concomitant sarcopenia and depressive symptoms.

Probable sarcopenia is associated with cognitive impairment among community-dwelling older adults: results from the FIBRA study

BACKGROUND

The link between sarcopenia and cognitive impairment has not yet been thoroughly evaluated, especially among older adults.

OBJECTIVE

To evaluate the relationship between probable sarcopenia and cognitive impairment among community-dwelling older adults in two Brazilian cities.

METHODS

Probable sarcopenia was assessed using the EWGSOP2 (2018) criteria. Thus, participants were classified as probably having sarcopenia if they had SARC-F (Strength, Assistance in walking, Rise from a chair, Climb stairs and Falls) ≥4 points and low grip strength. Cognitive function was evaluated through the Mini-Mental State Examination (MMSE), verbal fluency (VF) and clock drawing test (CDT).

RESULTS

In a sample of 529 older adults (mean age 80.8±4.9 years; mean education 4.2±3.67 years; 70.1% women), 27.3% of the participants had SARC-F≥4, 38.3% had low grip strength and 13.6% were classified as probable sarcopenia cases. After adjusting for possible confounders (age, sex, education, depression, diabetes, hypertension, leisure-time physical activity and obesity), probable sarcopenia was found to be associated with impairment in the MMSE (OR 2.52; 95%CI 1.42‒4.47; p=0.002) and in VF (OR 2.17; 95%CI 1.17‒4.01; p=0.014). Low grip strength was found to be associated with impairment in the MMSE (OR 1.83; 95%CI 1.18‒2.82; p=0.006) and in the CDT (OR 1.79; 95%CI 1.18‒2.73; p=0.006). SARC-F scores were found to be associated with impairment in the MMSE (OR 1.90; 95%CI 1.18‒3.06; p=0.008).

CONCLUSION

The results suggested that probable sarcopenia and its components present a significant association with cognitive deficits among community-dwelling older adults. Future longitudinal studies will further explore the causal relationship.

Iron accumulation in skeletal muscles of old mice is associated with impaired regeneration after ischaemia-reperfusion damage

BACKGROUND

Oxidative stress is implicated in the insidious loss of muscle mass and strength that occurs with age. However, few studies have investigated the role of iron, which is elevated during ageing, in age-related muscle wasting and blunted repair after injury. We hypothesized that iron accumulation leads to membrane lipid peroxidation, muscle wasting, increased susceptibility to injury, and impaired muscle regeneration.

METHODS

To examine the role of iron in age-related muscle atrophy, we compared the skeletal muscles of 3-month-old with 22- to 24-month-old 129SvEv FVBM mice. We assessed iron distribution and total elemental iron using laser ablation inductively coupled plasma mass spectrometry and Perls' stain on skeletal muscle cross-sections. In addition, old mice underwent ischaemia-reperfusion (IR) injury (90 min ischaemia), and muscle regeneration was assessed 14 days after injury. Immunoblotting was used to determine lipid peroxidation (4HNE) and iron-related proteins. To determine whether muscle iron content can be altered, old mice were treated with deferiprone (DFP) in the drinking water, and we assessed its effects on muscle regeneration after injury.

RESULTS

We observed a significant increase in total elemental iron (+43%, P < 0.05) and lipid peroxidation (4HNE: +76%, P < 0.05) in tibialis anterior muscles of old mice. Iron was further increased after injury (adult: +81%, old: +135%, P < 0.05) and associated with increased lipid peroxidation (+41%, P < 0.05). Administration of DFP did not impact iron or measures of lipid peroxidation in skeletal muscle or modulate muscle mass. Increased muscle iron concentration and lipid peroxidation were associated with less efficient regeneration, evident from the smaller fibres in cross-sections of tibialis anterior muscles (-24%, P < 0.05) and an increased percentage of fibres with centralized nuclei (+4124%, P < 0.05) in muscles of old compared with adult mice. Administration of DFP lowered iron after IR injury (PRE: -32%, P < 0.05 and POST: -41%, P < 0.05), but did not translate to structural improvements.

CONCLUSIONS

Muscles from old mice have increased iron levels, which are associated with increased lipid peroxidation, increased susceptibility to IR injury, and impaired muscle regeneration. Our results suggest that iron is involved in effective muscle regeneration, highlighting the importance of iron homeostasis in muscle atrophy and muscle repair.

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.

Are Sarcopenia and Cognitive Dysfunction Comorbid after Stroke in the Context of Brain-Muscle Crosstalk?

Stroke is a leading cause of death and disability and is responsible for a significant economic burden. Sarcopenia and cognitive dysfunction are common consequences of stroke, but there is less awareness of the concurrency of these conditions. In addition, few reviews are available to guide clinicians and researchers on how to approach sarcopenia and cognitive dysfunction as comorbidities after stroke, including how to assess and manage them and implement interventions to improve health outcomes. This review synthesises current knowledge about the relationship between post-stroke sarcopenia and cognitive dysfunction, including the physiological pathways, assessment tools, and interventions involved.

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.

Sarcopenia and adverse health-related outcomes: An umbrella review of meta-analyses of observational studies

OBJECTIVE

The purpose of this umbrella review was to assess the associations between sarcopenia and adverse health-related outcomes.

DESIGN

An umbrella review of meta-analyses of observational studies.

SETTING AND PARTICIPANTS

Patients with sarcopenia and controls without sarcopenia were included.

MEASURES

The PubMed, Web of Science and Embase were searched for relevant systematic review and meta-analysis. AMSTAR and GRADE system were used for methodological quality and evidence quality assessments, respectively.

RESULTS

Totally 54 outcomes extracted from 30 meta-analyses were analyzed. Twenty out of 21 prognostic outcomes indicated that sarcopenia was significantly associated with poorer prognosis of gastric cancer, hepatocellular cancer, urothelial cancer, head and neck cancer, hematological malignancy, pancreatic cancer, breast cancer, colorectal cancer, lung cancer, esophageal cancer, and ovarian cancer. Besides, 10 out of 16 postoperative outcomes suggested that sarcopenia significantly increased the risk of multiple postoperative complications and prolonged the length of hospitalization of patients with digestive cancer. In age-related outcomes, sarcopenia significantly increased the risk of dysphagia, cognitive impairment, fractures, falls, hospitalization, and all-cause mortality of elderly populations. Moreover, sarcopenia was also associated with higher level of albuminuria, risk of depression, and several metabolic diseases.

CONCLUSIONS AND IMPLICATIONS

Sarcopenia significantly affected a wide range of adverse health-related outcomes, particularly in patients of tumor and elderly populations. Because evidences of most outcomes were rated as "low" and "very low," more prospective cohort studies are required in the future.

Cognitive performance in relation to metabolic disturbances in patients with COPD

BACKGROUND & AIMS

Cognitive impairment (CI) and metabolic abnormalities, including the metabolic syndrome (MetS) and sarcopenia, are more prevalent in COPD patients compared to controls without diagnosed lung disease. Because earlier studies have shown these metabolic abnormalities may affect cognitive performance, this study investigated whether cognitive performance is more impaired in subgroups of COPD patients with MetS or sarcopenia.

METHODS

Cognitive performance patterns of 170 COPD patients referred for pulmonary rehabilitation (53.5% male, 63.4 ± 9.4 years, FEV₁ 54.5 ± 22.7% predicted) were compared between COPD subgroups stratified by presence of MetS and sarcopenia. Cognitive performance was assessed using a detailed neuropsychological test battery, which measured psychomotor speed (Stroop Color-Word Test, Concept Shifting Test, Letter-Digit Substitution Test), planning (Behavioral Assessment of the Dysexecutive Syndrome), working memory (Visual-Verbal Learning Test, Digit Span), verbal memory (Visual-Verbal Learning Test) and cognitive flexibility (Stroop Color-Word Test, Concept Shifting Test). MetS was determined according to the NCEP ATP-III criteria. Sarcopenia was determined based on decreased appendicular lean mass by dual-energy x-ray absorptiometry and impaired physical performance by 6-min walking distance.

RESULTS

MetS was observed in 54.7% and sarcopenia in 30.0% of COPD patients. The prevalence of general CI was not different between patients with and without MetS (30.4% and 39.0%, respectively) or those with and without sarcopenia (34.0% and 34.5%, respectively, both p > 0.05). Domain-specific cognitive performance was not different between metabolic subgroups, but those with sarcopenia displayed a lower prevalence of CI on verbal memory than those without (21.7% and 29.7%, respectively, p = 0.011). Only the digit span (working memory) subtest was significantly different between metabolic subgroups, in favor of those without MetS (p = 0.017).

CONCLUSION

Cognitive performance was not affected more in COPD patients with sarcopenia or MetS.

Can you see frailty? An exploratory study of the use of a patient photograph in the transcatheter aortic valve implantation programme

BACKGROUND

Frailty is an important consideration in the assessment of transcatheter aortic valve implantation patients. The documentation of a patient photograph to augment the objective measurement of frailty has been adopted by some transcatheter aortic valve implantation multidisciplinary (TAVI) programmes.

METHODS

We used a prospective two-part multimethod study design. In part A, we examined the concordance between the Essential Frailty Toolset (EFT) and the score attributed by healthcare professionals based on visual rating of photographs using kappa estimates and linear regression. In part B, we conducted a content analysis qualitative study to elicit information about how the TAVI multidisciplinary team used photographs to form impressions about frailty.

FINDINGS

Part A: 94 healthcare professionals (registered nurses/allied health 65%; physicians 35%) rated 40 representative photographs (women 42.5%; mean age 83.4±7.5; mobility aid 40%) between 0 (robust) and 5 (very frail). The estimate of weighted kappa was 0.2575 (95% confidence interval 0.082-0.433), indicating fair agreement between median healthcare professional visual and EFT score, especially when the EFT was 1 or 4. There was significant discordance among raters (kappa estimate 0.110, 95% confidence interval 0.079-0.141). Age, sex and mobility aid did not have a significant effect on score discordance. Part B: 12 members of the TAVI multidisciplinary team (registered nurses 27.5%; physicians 72.5%) were shown a series of six representative patient photographs. The following themes emerged from the data: (a) looking at the outside; (b) thinking about the inside; (c) use but with caution; and (d) a better approach.

CONCLUSION

A patient photograph offers complementary information to the multimodality assessment of TAVI patients.

SARC-F in hospitalized, geriatric medical patients - Feasibility, prevalence of risk of sarcopenia, and characteristics of the risk group, including one-year follow-up

BACKGROUND AND OBJECTIVES

SARC-F is an interview-based screening-tool recommended to rapidly screen for risk of sarcopenia - the loss of muscle mass and strength. Not previously investigated, this observational study aimed to assess the feasibility of the SARC-F screening tool in Danish geriatric medical patients, estimate the prevalence of risk, and investigate associations to predefined variables.

METHODS

This was an observational cohort study with a one-year follow-up. All non-isolated patients ≥65 years, understanding Danish and admitted to a Danish geriatric medical ward in the capital region of Denmark, were recruited. If readmitted during the study period, they were not included again. The following data were collected upon recruitment; demographics, nutritional risk screening (NRS-2002), BMI, calf-circumference, Barthel-index, health-related Quality of life (QoL), hand-grip strength (HGS), and length of hospital admission. Additionally, the one-year follow-up included mortality, admission(s) to hospital, and visits to the emergency-room.

RESULTS

From September 2017 to February 2018, 461 patients were admitted, 377 eligible, and 301 included. Study feasibility was 80%, and estimated feasibility if implemented in daily clinical practice was 85%, as some patients had to be excluded from screening due to cognitive impairment. The prevalence of the risk of sarcopenia upon admission for participants were 64.5%. Being at risk were characterized by significantly lower HGS, Barthel-index, and QoL, as well as longer admissions (men only), and one-year mortality (female only) (P ≤ 0.05).

CONCLUSION

Use of SARC-F is feasible in a geriatric setting, but only in older adults without severe cognitive problems. Risk of sarcopenia among geriatric patients ≥65 years is high, and the risk group is characterized by lower strength, functional- and QoL measurements, longer hospitalization (men only), and increased mortality (women only).

The "develOpment of metabolic and functional markers of Dementia IN Older people" (ODINO) Study: Rationale, Design and Methods

Mild cognitive impairment (MCI), also termed mild neurocognitive disorder, includes a heterogeneous group of conditions characterized by declines in one or more cognitive domains greater than that expected during "normal" aging but not severe enough to impair functional abilities. MCI has been associated with an increased risk of developing dementia and even considered an early stage of it. Therefore, noninvasively accessible biomarkers of MCI are highly sought after for early identification of the condition. Systemic inflammation, metabolic perturbations, and declining physical performance have been described in people with MCI. However, whether biological and functional parameters differ across MCI neuropsychological subtypes is presently debated. Likewise, the predictive value of existing biomarkers toward MCI conversion into dementia is unclear. The "develOpment of metabolic and functional markers of Dementia IN Older people" (ODINO) study was conceived as a multi-dimensional investigation in which multi-marker discovery will be coupled with innovative statistical approaches to characterize patterns of systemic inflammation, metabolic perturbations, and physical performance in older adults with MCI. The ultimate aim of ODINO is to identify potential biomarkers specific for MCI subtypes and predictive of MCI conversion into Alzheimer's disease or other forms of dementia over a three-year follow-up. Here, we describe the rationale, design, and methods of ODINO.

Sarcopenia Is Associated with Cognitive Decline and Falls but Not Hospitalization in Community-Dwelling Oldest Old in China: A Cross-Sectional Study

Background

The aim of this study was to investigate the association between sarcopenia and cognitive decline, falls, and hospitalization in a Chinese elderly population.

Material/Methods

This cross-sectional survey was conducted between November 2018 and May 2019, and enrolled only older adults aged 80 years or over (oldest old). We diagnosed sarcopenia using the Asian Working Group for Sarcopenia criteria. Demographic characteristics, disease history, smoking status, drinking status, cognitive function, falls, and hospitalization events in the previous 12 months were acquired by face-to-face interview. Cognitive status was evaluated by the Montreal Cognitive Assessment. Falls was ascertained by the question “Have you fallen down in the last 12 months?” Hospitalization was ascertained by the question “Have you received inpatient care in the past year?”

Results

A total of 582 participants (aged 80–99 years and 42.3% male) were included. The prevalence of sarcopenia was 21.7% (95% confidence interval [CI]: 17.3–26.2%) and 33.3% (95% CI: 27.4–39.3%) for females and males, respectively. Among the study population, the prevalence of cognitive decline was 60.8%; the proportions of the oldest old who had falls or hospitalization in the past 12 months were 18.1% and 34.3%, respectively. Multivariate analyses showed that sarcopenia was significantly and independently associated with cognitive decline [odds ratio (OR)=1.96, 95% CI: 1.17–3.27] and falls (OR=2.00, 95% CI: 1.17–3.43) but not associated with hospitalization (OR=1.32, 95% CI: 0.83–2.08).

Conclusions

Our results showed that sarcopenia was significantly and independently associated with cognitive decline and falls, but not associated with hospitalization, in the community-dwelling oldest old.

Creatinine to Cystatin C Ratio as a Marker of Bone Property in Older Adults: The J-SHIPP Study

OBJECTIVES

To clarify whether serum creatinine to cystatin C ratio (CCR), a marker of muscle mass and muscle function may be used as a simple marker of bone property.

DESIGN

A cross-sectional analysis.

SETTING

A general population-based observation study.

PARTICIPANTS

1,606 middle-aged to elderly (≥50 years, mean age: 66.9 ± 7.5 years old) men (n = 642) and post-menopausal women (n = 964).

MEASUREMENT

Speed of sound (SOS) at the calcaneal bone was used as a surrogate marker of bone mineral density. The cross-sectional area of the muscle at the mid-thigh was measured using computed tomography.

RESULTS

There was significant linear correlation between the quartiles of CCR and SOS (Q1: 1,495 ± 25, Q2: 1,499 ± 24, Q3: 1,507 ± 26, Q4: 1,511 ± 25 m/sec; P < 0.001) even in a sex-separated analysis. This association was independent of major covariates (Q1: β = -0.126, P < 0.001; Q2: β = -0.096, P = 0.001; Q3: β = -0.022; P = 0.412, Q4: reference) and the mid-thigh muscle mass, while creatinine alone or eGFR did not show clear association with SOS.

CONCLUSION

The CCR may be used as a simple marker of bone property independently of muscle mass in a general population with preserved renal function.