Sarcopenia and motoric cognitive risk syndrome: a moderated mediation model

Associations of nutritional intake and inflammatory factors with sarcopenia in community-dwelling older adults: a cross-sectional study

PURPOSE

Sarcopenia is an age-related disease that is related to nutritional intake and chronic low-grade inflammation. The aim of this study was to investigate the association of dietary intake, inflammatory markers and sarcopenia among the community-dwelling older adults.

METHODS

A total of 1001 older adults aged 60 and above were recruited. According to the criteria established by the Asian Working Group for Sarcopenia 2019, this paper assessed the presence of sarcopenia and using a Food Frequency Questionnaire to evaluate daily dietary intake. Serum levels of inflammatory markers were measured using the ELISA method.

RESULTS

A total of 1001 participants took part in the study (mean 70.6 years), comprising 396 males and 605 females, the prevalence of sarcopenia was 19.6%. Multivariate analysis revealed that high levels of leucine, methionine, threonine, histidine, aspartic acid, calcium, zinc, and vitamin C were associated with a lower risk of sarcopenia. Higher dietary inflammatory index scores were associated with a higher risk of sarcopenia (OR  1.67, 95% CI 1.12-2.47). Higher tumor necrosis factor-like weak inducer of apoptosis (TWEAK) (OR 1.04, 95% CI 1.02-1.07) was associated with a higher risk of sarcopenia, and a lower skeletal muscle mass, strength, and physical function. Conversely, higher insulin-like growth factor-1 (IGF-1) (OR 0.83, 95% CI 0.74-0.94) and glutathione S-transferase (GST) (OR 0.75, 95% CI 0.61-0.91) were associated with a lower risk of sarcopenia.

CONCLUSIONS

This cross-sectional study revealed alterations in amino acid and micronutrient intake among older adults with sarcopenia. The levels of TWEAK were associated with an increased risk of sarcopenia, whereas IGF-1 and GST were associated with a reduced risk of sarcopenia.

Measurement Practice of Slow Gait Speed for Motoric Cognitive Risk Syndrome: A Systematic Review

OBJECTIVES

Individuals with motoric cognitive risk (MCR) syndrome have a high dementia risk. However, a knowledge gap exists in the measurement procedure for slow gait speed, which is a crucial component of MCR diagnosis. The study aimed to systematically review slow gait speed measurement practices in MCR diagnosis to identify critical constructs in gait speed measurement procedure.

DESIGN

Systematic review.

SETTING AND PARTICIPANTS

Included studies were conducted in clinical and community settings, involving participants with MCR receiving gait speed measurement.

METHODS

A systematic search across PubMed, Medline, Embase, CINHAL (EBSCO), Web of Science, Cochrane Library, and ProQuest Dissertation from inception until January 2024 for articles with detailed MCR diagnosis. Study quality was evaluated with the Joanna Briggs Institute (JBI) Critical Appraisal Checklists and slow gait speed measurement methods were summarized through narrative synthesis.

RESULTS

From 27,600 unique entries, 50 relevant studies with 55 cohorts were identified and included in the review. Slow gait speed measurement methods in existing MCR studies showed heterogeneity in measurement tools, start/end protocols and buffer distance, walking test distance, number of tests, calculation methods, and cutoff values. Commonly, manual stopwatches and 4-meter walking test distance with a 2-meter buffer at each end at a usual pace were used, averaging 2 tests for gait speed analysis, with the need for cohort-specific slow gait cutoff values.

CONCLUSIONS AND IMPLICATIONS

The measurement practices of slow gait speed in MCR diagnosis were heterogeneous. A relatively comprehensive gait speed measurement procedure with 7 constructs was initially delineated in this study based on synthesis analysis, with the potential to improve diagnostic accuracy and consistency of MCR, although further validation is still needed.

Associations of Body Mass Index and Percent Body Fat with Osteoporosis, Sarcopenia, and Osteosarcopenia: A Retrospective Study Based on Postmenopausal Women in China

Background/Objectives: Alterations in the body mass index (BMI) and percent body fat (PBF) have been considered to be related to aging-induced changes in bone and muscle. This study aimed to evaluate the associations of the BMI and PBF with osteoporosis, sarcopenia, and osteosarcopenia in postmenopausal women. Methods: A total of 342 participants who underwent musculoskeletal function assessments at the First Affiliated Hospital of Sun Yat-sen University between January 2015 and December 2022 were retrospectively screened. The diagnosis of osteoporosis was based on the WHO criteria, and sarcopenia was diagnosed according to the 2019 consensus of the Asian Working Group for Sarcopenia. Results: The BMI was positively correlated with the musculoskeletal function assessment parameters (bone mineral density, relative skeletal muscle index, and grip strength) and identified as an independent protective factor for sarcopenia alone (OR = 0.592, 95% CI: 0.455-0.769) or osteosarcopenia (OR = 0.411, 95% CI: 0.319-0.529), with a moderate diagnostic accuracy (area under the curve [AUC] = 0.682) for the former and a high diagnostic accuracy (AUC = 0.823) for the latter. However, the PBF was negatively correlated with the relative skeletal muscle index and identified as a risk factor for osteosarcopenia (OR = 1.404, 95% CI: 1.007-1.959), with a moderate diagnostic accuracy (AUC = 0.613). Conclusions: A higher BMI and lower PBF were associated with a lower prevalence of osteosarcopenia in postmenopausal women. Further research is required to elucidate the independent effects of the BMI and PBF on bone health.

Association between probable sarcopenia and dementia risk: a prospective cohort study with mediation analysis

The role of alcohol consumption as a mediator in the risk between sarcopenia and dementia remains inadequately studied. There is currently limited research on whether the association between sarcopenia and the risk of Alzheimer's disease (AD) is influenced by genetic susceptibility. Our study incorporated a total of 483,637 baseline non-dementia participants, who were classified into groups of individuals with no sarcopenia and those with probable sarcopenia based on the definition. We employed Cox proportional hazards models to evaluate the association between probable sarcopenia and the risk of all cause dementia (ACD), AD, and vascular dementia (VD). We conducted mediation analysis to explore the role of alcohol consumption in the association between probable sarcopenia and the risk of ACD, AD, and VD. During the median follow-up period of 13.6 years, we documented 9000 new cases of ACD (including 4061 AD and 2025 VD). Fully adjusted multivariate model revealed a significant correlation between probable sarcopenia and elevated risk for ACD (HR = 1.54, 95% CI: 1.46-1.62, p < 0.001), AD (HR = 1.32, 95% CI: 1.21-1.43, p < 0.001), and VD (HR = 1.69, 95% CI: 1.52-1.89, p < 0.001). Mediation analysis elucidates that alcohol consumption explained 12.8%, 15.2%, and 11.1% of the associations of probable sarcopenia with the risk of ACD, AD, and VD, respectively. An interactive relationship prevails between probable sarcopenia and genetic factors (p for interaction <0.001), and regardless of the degree of genetic risk, probable sarcopenia correlates with an elevated AD risk. Our study reveals a significant association between probable sarcopenia and an increased risk of dementia, with alcohol consumption playing a mediating role in this association. There is an interaction between probable sarcopenia and genetic susceptibility related to the risk of AD.

Sarcopenia and frailty among the elderly population in the community: An observational study

Context

There are few studies on the prevalence of sarcopenia and frailty in India.

Aims

The aim of this study was to assess sarcopenia and frailty using simple clinical tools among the elderly population in the community.

Settings and Design

This was an observational study. The elderly population with an age group of >60 years residing in villages within 10-15 km of Sumandeep Vidyapeeth, Vadodara, formed the sampling frame of the study.

Methods and Material

A total of 785 participants were approached, of whom 556 were included in the study based on inclusion criteria. Participants were assessed for grip strength, muscle mass, gait speed, and frailty.

Statistical Analysis Used

The data were analyzed using STATA-IC statistical software version 13. A nonparametric Chi-square (χ2) test was used for categorical variables, and an independent-samples t-test was used to analyze the difference between various variables. Statistical significance was considered at P < 0.05 with a 95% confidence interval (CI).

Results

Based on the Indian criteria, 205 participants (36.1%) were diagnosed as having sarcopenia, and 351 participants (63%) were diagnosed as having "no sarcopenia." 5.6% of participants were found to be frail, 19.2% to be pre-frailty, and 75.2% to be no frailty. The χ2 analysis showed a significant association of sarcopenia with gender and different age groups (P value < 0.001).

Conclusions

In this study, 36.9% of the elderly participants were found to have "sarcopenia," and 5.6% of the participants had frailty. Simple clinical tools used were easy to administer and suitable for field screening.

Predictors for the development of motoric cognitive risk syndrome in older adults

BACKGROUND

Motoric cognitive risk (MCR) syndrome refers to a condition where both slow gait and memory complaints coexist, which heightens their vulnerability to developing dementia. Considering that the risk factors of MCR are elucidated from cross-sectional studies and also likely vary based on socioeconomic status, we conducted a community-based longitudinal study to determine the predictors of MCR among older adults in Malaysia.

METHODS

Out of 1,249 older participants (aged 60 years and above) without MCR at baseline (Wave II of LRGS-TUA cohort study), 719 were successfully followed up after 3.5 years to identify predictors of subsequent MCR development. A comprehensive interview-based questionnaire was administered for sociodemographic information, cognitive function, psychosocial, functional status, and dietary intake. Anthropometric measurements, body composition, and physical performance were assessed. Univariate analyses were performed for each variable, followed by a hierarchical logistic regression analysis to identify the predictors of MCR that accounted for confounding effects between the studied factors.

RESULTS

The incidence rate of MCR was 4.0 per 100 person-years. Smoking (Adjusted Odd Ratio (Adj OR) = 1.782; 95% Confidence Interval (CI):1.050-3.024), hypertension (Adj OR = 1.725; 95% CI:1.094-2.721), decreased verbal memory as assessed by the lower Rey Auditory Verbal Learning Test (RAVLT) (Adj OR = 1.891; 95% CI:1.103-3.243), and decreased functional status measured using instrumental activity of daily living (IADL) (Adj OR = 4.710; 95% CI:1.319-16.823), were predictors for MCR incidence.

CONCLUSIONS

Our study results provide an initial reference for future studies to formulate effective preventive management and intervention strategies to reduce the growing burden of adverse health outcomes, particularly among Asian older adults.

Muscle density, but not size, is independently associated with cognitive health in older adults with hip fractures

Emerging evidence indicates a complex interplay between skeletal muscle and cognitive function. Despite the known differences between muscle quantity and quality, which can be measured via computed tomography (CT), the precise nature of their associations with cognitive performance remain underexplored. To investigate the links between muscle size and density and cognitive impairment (CI) in the older adults with hip fractures, we conducted a post hoc, cross-sectional analysis within a prospective cohort study on 679 patients with hip fractures over 65. Mini-Mental State Examination (MMSE) and routine hip CT imaging were utilized to assess cognition function and muscle characteristics in older adults with hip fractures. The CT scans provided data on cross-sectional area and attenuation for the gluteus maximus (G.MaxM) and the combined gluteus medius and minimus (G.Med/MinM). Participants were categorized into CI and non-CI groups based on education levels and MMSE scores. Multivariate logistic regressions, propensity score (PS) methods, and subgroup analysis were employed to analyze associations and validate findings. This study included 123 participants (81.6 ± 6.8 years, 74% female) with CI and 556 participants (78.5 ± 7.7 years, 72% female) without. Compared to the non-CI group, muscle parameters, especially density, were significantly lower in the CI group. Specifically, G.Med/Min muscle density, but not size was robustly associated with CI (odds ratio (OR) = 0.77, 95% confidence interval = 0.62-0.96, P = 0.02), independent of other medical situations. Sensitivity analysis corroborated that G.Med/Min muscle density was consistently lower in the CI group than the non-CI group, as evidenced in the PS matched (P = 0.024) and weighted cohort (P = 0.033). Enhanced muscle parameters, particularly muscle density in the G.Med/MinM muscle, correlate with a lower risk of CI. Muscle density demonstrates a stronger association with cognitive performance than muscle size, highlighting its potential as a key focus in future cognitive health research.

Association of Handgrip Strength Weakness and Asymmetry With Incidence of Motoric Cognitive Risk Syndrome in the China Health and Retirement Longitudinal Study

BACKGROUND AND OBJECTIVES

Motoric cognitive risk (MCR) syndrome is a type of pre-dementia. It is defined as the co-occurrence of subjective cognitive complaints and a slow gait speed. A recent study found that handgrip strength (HGS) asymmetry is associated with an increased risk of neurodegenerative disorders. We aimed to investigate the associations of HGS weakness and asymmetry separately and together with MCR incidence among older Chinese adults.

METHODS

Data from the 2011 and 2015 waves of the China Health and Retirement Longitudinal Study were used. HGS values <28 kg for male participants and <18 kg for female participants were considered HGS weaknesses. HGS asymmetry was assessed by the ratio of nondominant to dominant HGS. We used 3 different cutoff values of HGS ratio to define asymmetry, including 10%, 20%, and 30%. Specifically, HGS ratios <0.90 or >1.10 (10%), <0.80 or >1.20 (20%), and <0.70 or >1.30 (30%) were classified as asymmetry. The participants were classified into 4 groups: neither weakness nor asymmetry (neither), asymmetry only, weakness only, and weakness and asymmetry (both). The association between baseline HGS status and 4-year incidence of MCR was examined using logistic regression analyses.

RESULTS

A total of 3,777 participants 60 years and older were included in the baseline analysis. The prevalence of MCR at the baseline was 12.8%. Participants with asymmetry only, weakness only, and both showed significantly increased risk of MCR. After excluding participants with MCR at baseline, 2,328 participants were included in the longitudinal analysis. There were 111 MCR cases (4.77%) over the 4-year follow-up period. Participants with HGS weakness and asymmetry together at baseline had increased odds of incident MCR (HGS ratio at 10%: odds ratio [OR] 4.48, p < 0.001; HGS ratio at 20%: OR 5.43, p < 0.001; HGS ratio at 30%: OR 6.02, p < 0.001).

DISCUSSION

These results show that the presence of both HGS asymmetry and weakness is associated with MCR incidence. The early recognition of HGS asymmetry and weakness may be helpful in the prevention and treatment of cognitive dysfunction.

Chronic pain increases the risk of motoric cognitive risk syndrome at 4 years of follow-up: evidence from the China Health and Retirement Longitudinal Study

BACKGROUND AND PURPOSE

Slower gait speed and subjective cognitive concerns are characteristics of the motoric cognitive risk (MCR) syndrome. This study aimed to examine if changes in pain may be hallmarks of early MCR, through investigating the magnitude of the association of chronic pain and the risk of MCR at 4 years follow-up.

METHODS

In total, 3711 participants without dementia or any mobility disability aged ≥60 years were studied, including 1413 with chronic pain, enrolled in the China Health and Retirement Longitudinal Study, a prospective cohort study. MCR assessed at wave 1 (2011) and wave 3 (2015) was used as the exposure. Cox regression analysis was used to examine the longitudinal association between chronic pain and MCR after adjusting for individual factors, behaviors/physiology factors and societal factors. Four years later, the incident MCR was evaluated.

RESULTS

After adjusting for individual factors, chronic pain was found to increase the risk of MCR development over time by about 1.5 times (hazard ratio 1.562, 95% confidence interval 1.228-1.986; p < 0.001) and to be linked with incident MCR at baseline (odds ratio 1.397, 95% confidence interval 1.149-1.698; p < 0.001). These associations remained substantial when behaviors/physiology factors and societal factors were taken into account in the analytical models.

CONCLUSIONS

The findings of our study imply that incident MCR may be exacerbated by chronic pain. Further exploration is required to find out whether chronic pain is a modifiable risk factor for MCR.

Demand Coupling Drives Neurodegeneration: A Model of Age-Related Cognitive Decline and Dementia

The societal burden of Alzheimer's Disease (AD) and other major forms of dementia continues to grow, and multiple pharmacological agents directed towards modifying the pathological "hallmarks" of AD have yielded disappointing results. Though efforts continue towards broadening and deepening our knowledge and understanding of the mechanistic and neuropathological underpinnings of AD, our previous failures motivate a re-examination of how we conceptualize AD pathology and progression. In addition to not yielding effective treatments, the phenotypically heterogeneous biological processes that have been the primary area of focus to date have not been adequately shown to be necessary or sufficient to explain the risk and progression of AD. On the other hand, a growing body of evidence indicates that lifestyle and environment represent the ultimate level of causation for AD and age-related cognitive decline. Specifically, the decline in cognitive demands over the lifespan plays a central role in driving the structural and functional deteriorations of the brain. In the absence of adequate cognitive stimulus, physiological demand-function coupling leads to downregulation of growth, repair, and homeostatic processes, resulting in deteriorating brain tissue health, function, and capacity. In this setting, the heterogeneity of associated neuropathological tissue hallmarks then occurs as a consequence of an individual's genetic and environmental background and are best considered downstream markers of the disease process rather than specific targets for direct intervention. In this manuscript we outline the evidence for a demand-driven model of age-related cognitive decline and dementia and why it mandates a holistic approach to dementia treatment and prevention that incorporates the primary upstream role of cognitive demand.

Sarcopenia and nervous system disorders

Sarcopenia has an insidious start that can induce physical malfunction, raise the risk of falls, disability, and mortality in the old, severely impair the aged persons' quality of life and health. More and more studies have demonstrated that sarcopenia is linked to neurological diseases in recent years. This review examines the advancement of sarcopenia and neurological illnesses research.