Brain CT can predict low lean mass in the elderly with cognitive impairment: a community-dwelling study

Association of head and neck CT-derived sarcopenia with mortality and adverse outcomes: A systematic review

BACKGROUND

There is growing interest in the association of CT-assessed sarcopenia with adverse outcomes in non-oncological settings.

PURPOSE

The aim of this systematic review is to summarize existing literature on the prognostic implications of CT-assessed sarcopenia in non-oncological patients.

MATERIALS AND METHODS

Three independent authors searched Medline/PubMed, Embase and Cochrane Library up to 30 December 2023 for observational studies that reported the presence of sarcopenia defined on CT head and neck in association with mortality estimates and other adverse outcomes, in non-oncological patients. The quality of included studies were assessed using the Quality of Prognostic Studies tool.

RESULTS

Overall, 15 studies (3829 participants) were included. Nine studies were at low risk of bias, and six were at moderate risk of bias. Patient populations included those admitted for trauma or treatment of intracranial aneurysms, ischemic stroke, transient ischemic attack, and intracranial stenosis. Sarcopenia was associated with increased 30-day to 2-year mortality in inpatients and patients undergoing carotid endarterectomy or mechanical thrombectomy for acute ischemic stroke. Sarcopenia was also associated with poorer neurological and functional outcomes, increased likelihood of admission to long-term care facilities, and longer duration of hospital stays. The observed associations of sarcopenia with adverse outcomes remained similar across different imaging modalities and methods for quantifying sarcopenia.

CONCLUSION

CT-assessed sarcopenia was associated with increased mortality and poorer outcomes across diverse patient populations. Measurement and early identification of sarcopenia in vulnerable patients allows for enhanced prognostication, and focused allocation of resources to mitigate adverse outcomes.

Casual associations between brain structure and sarcopenia: A large-scale genetic correlation and mendelian randomization study

Sarcopenia presenting a critical challenge in population-aging healthcare. The elucidation of the interplay between brain structure and sarcopenia necessitates further research. The aim of this study is to explore the casual association between brain structure and sarcopenia. Linkage disequilibrium score regression (LDSC) was conducted to estimate the genetic correlations; MR was then performed to explore the causal relationship between Brain imaging-derived phenotypes (BIDPs) and three sarcopenia-related traits: handgrip strength, walking pace, and appendicular lean mass (ALM). The main analyses were conducted using the inverse-variance weighted method. Moreover, weighted median and MR-Egger were conducted as sensitivity analyses. Genetic association between 6.41% of BIDPs and ALM was observed, and 4.68% of BIDPs exhibited causal MR association with handgrip strength, 2.11% of BIDPs were causally associated with walking pace, and 2.04% of BIDPs showed causal association with ALM. Volume of ventromedial hypothalamus was associated with increased odds of handgrip strength (OR: 1.18, 95% CI: 1.02 to 1.37) and ALM (OR: 1.05, 95% CI: 1.01 to 1.09). Mean thickness of G-pariet-inf-Angular was associated with decreased odds of handgrip strength (OR: 0.83, 95% CI: 0.70 to 0.97) and walking pace (OR: 0.97, 95% CI: 0.93 to 0.99). As part of the brain structure forward causally influences sarcopenia, which may provide new perspectives for the prevention of sarcopenia and offer valuable insights for further research on the brain-muscle axis.

Meta-analysis on the interrelationship between sarcopenia and mild cognitive impairment, Alzheimer's disease and other forms of dementia

Sarcopenia has been associated with adverse health outcomes, including cognitive dysfunction. However, its specific interrelationship with neurocognitive disorders such as mild cognitive impairment (MCI), Alzheimer's disease (AD) or other types of dementia has not been thoroughly explored. This meta-analysis aims to summarize the existing evidence on this interrelationship. This systematic review was pre-registered on PROSPERO (CRD42022366309) and reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 guidelines. Databases, including PubMed, Embase, CINAHL, Scopus, Web of Science, PEDro, SPORTDiscus and the Cochrane Central Register of Controlled Trials, and the data registry ClinicalTrials.gov were searched from inception to 8 June 2023. Observational studies (cross-sectional and cohort) and interventional studies reporting on the association and prevalence of sarcopenia in MCI, AD or other types of dementia in adults ≥50 years were included. For the meta-analysis, pooled odds ratios (OR) with 95% confidence intervals (CI) were calculated for the association of sarcopenia with the neurocognitive disorders using random-effects/fixed-effects models. Subgroup analyses were performed to identify potential sources of heterogeneity. A total of 77 studies consisting of 92 058 subjects were finally included in the qualitative analysis (71 cross-sectional, 4 cohort and 2 interventional studies). Studies were heterogeneous, using different diagnostic criteria to define both sarcopenia and cognitive status. The majority of studies (n = 38) included Asian community-dwelling older adults. Most studies investigated the association of sarcopenia with AD (33/77) and MCI (32/77). For studies focusing on other forms of dementia, two studies included Lewy body dementia and one study included Parkinson's dementia, whereas the remaining studies did not specify dementia aetiology (n = 21). Three cohort studies explored the association between sarcopenia and incident MCI, whereas only one cohort study explored the association between dementia and incident sarcopenia. Two interventional studies investigated whether an exercise programme could prevent the progression of sarcopenia in older adults with dementia or AD. The information for the meta-analysis was extracted from 26 studies. Sarcopenia was significantly associated with MCI (pooled OR = 1.58, 95% CI 1.42-1.76) (n = 14), AD (pooled OR = 2.97, 95% CI 2.15-4.08) (n = 3) and non-AD dementia (pooled OR = 1.68, 95% CI 1.09-2.58) (n = 9). The significance and magnitude of the associations differed in subgroup analyses by study design, population, definition of sarcopenia or used tool to measure cognitive status. This meta-analysis showed that sarcopenia is significantly associated with MCI, AD and other types of dementia. These findings suggest the importance of early screening and prevention of sarcopenia in older people with cognitive dysfunction, although further longitudinal research is needed to clarify the causal relationship.

Unveiling the muscle-brain axis: A bidirectional mendelian randomization study investigating the causal relationship between sarcopenia-related traits and brain aging

BACKGROUND

Observational studies suggest an association between sarcopenia-related traits and brain aging, but whether this association reflects a causal relationship remains unclear. This study aims to employ Mendelian randomization (MR) methods to investigate the causal impact of sarcopenia-related traits on brain aging.

METHODS

This study presents a comprehensive analysis of genome-wide association study (GWAS) summary data associated with sarcopenia-related traits. The data were derived from a large-scale cohort, encompassing measures such as grip strength, lean body mass, and walking pace. Measurements of brain aging were obtained from neuroimaging genetics, utilizing meta-analysis (ENIGMA) to combine magnetic resonance imaging (MRI) data from 33,992 participants. The primary methodology employed in this analysis was the inverse-variance-weighted method (IVW). Additionally, sensitivity analyses were conducted, to assess heterogeneity and pleiotropy.

RESULT

Appendicular lean mass(ALM) is negatively correlated with Pallidum aging; Whole body fat-free mass shows a negative correlation with Amygdala aging; Leg fat-free mass (left) and Leg fat-free mass (right) are negatively correlated with Pallidum aging; Usual walking pace is positively correlated with Nucleus Accumbens aging. Cerebellum WM aging is negatively correlated with Leg fat-free mass (left) and Leg fat-free mass (right); Hippocampus aging is negatively correlated with Hand grip strength (left) and Hand grip strength (right). Ventricles aging is positively correlated with Usual walking pace; Nucleus Accumbens aging is positively correlated with Leg fat-free mass (left) and Leg fat-free mass (right); Putamen aging is positively correlated with ALM.

CONCLUSION

Our study confirms that reduced muscle mass speeds up brain aging. Walking too fast raises the risk of brain aging, while maintaining or increasing appendicular lean mass, overall muscle mass, and muscle mass in both legs lowers the risk of brain aging.

Prevalence and Factors Influencing Sarcopenia Among Community-Dwelling Older Adults Using the Asian Working Group for Sarcopenia Definition

OBJECTIVE

This study aimed to explore the prevalence and impact of related factors for sarcopenia among community-dwelling older people in Chongming district, China, according to the diagnostic criteria of the Asia Working Group for Sarcopenia-2019.

METHODS

We conducted a cross-sectional study from April 2021 to December 2021. Diagnosis of sarcopenia (non-sarcopenia, possible sarcopenia, sarcopenia, and severe sarcopenia) was based on appendicular skeletal muscle mass index, handgrip strength, gait speed, and the 5-time chair stand test. Staff collected all subjects' clinical and sociodemographic characteristics, cardiovascular disease (CVD) risk factors, inflammatory markers, physical activity (PA), and daily lifestyle activities to identify sarcopenia-related factors.

RESULTS

A total of 1407 older people aged ≥ 65 years were enrolled into the study (58.7% female). The prevalence of confirmed sarcopenia was 19.6% (17.1% in females and 23.1% in males). The prevalence of possible sarcopenia, sarcopenia, and severe sarcopenia were 19.7% (22.2% in females, 16.2% in males), 11.9% (10.1% in females, 14.5% in males), and 7.7% (7% in females, 8.6% in males), respectively. Increasing age, gender, depression status, and high-fat mass were associated with an increased likelihood of sarcopenia in all subjects. In females, living alone, high-fat mass, lower body mass index (BMI), lower body weight, and have no time spent doing housework increased the likelihood of sarcopenia. In males, depression status, high-fat mass, higher neutrophils-to-lymphocytes ratio (NLR), lower BMI, lower body weight increased the likelihood of sarcopenia.

CONCLUSION

Our study showed a high prevalence of sarcopenia among community-dwelling older people in the Chongming district. Detection, prevention, and treatment efforts are needed to reduce the impact of sarcopenia in older, rural communities in China.

Decline in skeletal muscle mass is associated with cognitive decline in type 2 diabetes mellitus

AIMS

To examine the longitudinal association between skeletal muscle mass (SMM) loss and cognitive decline over time in type 2 diabetes mellitus (T2DM).

METHODS

We conducted a prospective cohort study of 453 patients from SMART2D cohort with follow-up intervals of 1.6 to 6.4 years. Baseline and follow-up measurements included bio-impedance analysis (BIA) measure of skeletal muscle mass index (SMI) and Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) measure of cognitive function. We examined the association between annual rate of SMI and RBANS scores using linear regression, adjusting for demographics, education, depression, clinical co-variables and presence of apolipoprotein E4 (APOE) _Ɛ4 allele.

RESULTS

The mean age of participants was 60.3 ± 7.4 years. Compared to patients with Tertile 1 SMI change, the group with greater SMI decline (Tertile 3 SMI change) experienced 0.30 decline in RBANS total score (95%CI -0.57 to -0.03; p = 0.030) in the adjusted analysis. RBANS scores for subdomains in immediate memory and visuo-spatial/construction were lower in Tertile 3 SMI change group with corresponding coefficients -0.54 (95%CI -1.01 to -0.06; p = 0.026), and -0.71 (95%CI -1.30 to -0.12; p = 0.019) respectively.

CONCLUSION

In patients with T2DM, BIA measure of muscle mass loss over time was independently associated with cognitive decline globally and in the domains of memory and visuo-spatial/construction.