Cross-Sectional Examination of Homocysteine Levels with Sarcopenia and Its Components in Memory Clinic Outpatients

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.

Association between serum homocysteine and sarcopenia among hospitalized older Chinese adults: a cross-sectional study

OBJECTIVE

Hyperhomocysteinemia (HHcy) is considered to increase the risk of sarcopenia (S) and remains controversial. In this study, we aimed to investigate the prevalence of S among older Chinese adults and explore whether homocysteine (Hcy) was independently associated with S.

METHODS

This cross-sectional study was performed among older adults hospitalized in the Geriatric Hospital of Nanjing Medical University between June 2017 and December 2021. We measured all participants' serum Hcy levels, hand grip strength, gait speed and appendicular skeletal muscle index(ASMI) using bioelectrical impedance analysis (BIA). S was defined based on the criteria of the Asian Working Group for Sarcopenia 2 (AWGS2), which included muscle mass (ASMI< 7.0 kg/m² for men and ASMI< 5.7 kg/m² for women by BIA) and low muscle strength (handgrip strength < 28 kg for men and < 18 kg for women), and/or gait speed < 1.0 m/s. HHcy defined as Hcy ≥10 μmol/L. The strength of the association between Hcy and the risk of S was analyzed by multivariate logistic regression using three models that adjusted for possible confounding variables to calculate the odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

Among the 441 subjects, 161 (36.5%) were diagnosed with S, and 343 (77.8%) were diagnosed with HHcy. A significant association was detected between S and serum Hcy per 1-μmol/L increase after adjustment for age, gender, education, smoking, body mass index (BMI), Mini Nutritional Assessment Short Form (MNA-SF), alanine aminotransferase (ALT), C-reactive protein (CRP), hemoglobin (Hb), albumin (ALB), diabetes, kidney disease, and statin use (OR = 1.07, 95% CI = 1.03-1.12, P = 0.002). The OR for S in the HHcy group (≥10 μmol/L) was nearly 5-fold that in the normal Hcy group (OR 4.96, 95% CI 2.67-9.24, P < 0.001). In a gender-based subgroup analysis that adjusted for age, education, smoking, BMI, MNA-SF, ALT, CRP, Hb, and ALB, female subjects with HHcy had an increased risk of S (OR 10.35, 95% CI 2.84-37.68, P < 0.001).

CONCLUSIONS

Our results demonstrated that elevated Hcy levels have an independent association with S in older adults. This suggests that the downward adjustment of HHcy (cutoff value < 10 μmol/l) might decrease the risk of S.

Association between sarcopenia and cognitive impairment in the older people: a meta-analysis

PURPOSE

The effects of sarcopenia on the older people are profound, increasing the risk of adverse outcomes for older patients. Although the substantial impact of sarcopenia on maintaining functional independence and adverse health outcomes has been described many times in the past, the link between sarcopenia and cognitive impairment in older adults remains lacking in evidence and controversial. Therefore, we conducted a comprehensive search of available national and international databases and carried out a meta-analysis to examine the association between sarcopenia in older people and cognitive impairment.

METHODS

Relevant experiments had been recognized via looking out electronic databases and conference sessions. The present study included case-control, cohort, or cross-sectional studies of the association between sarcopenia and cognitive impairment in the older people.

RESULTS

The meta-analysis included 26 articles and 18,788 participants were involved after assessment of eligibility. The results of this meta-analysis showed that the risk of developing cognitive impairment was significantly higher in patients with sarcopenia than in those without sarcopenia [OR = 1.75; 95% CI = 1.57, 1.95; P < 0.00001], MMSE score of sarcopenia group was lower than that of non-sarcopenia group, the difference was statistically significant [OR = - 2.23; 95% CI = - 2.48, - 1.99; P < 0.00001].

CONCLUSION

Overall, this meta-analysis showed an association between sarcopenia and cognitive impairment in the older people, demonstrating a significant association between sarcopenia and cognitive impairment. This suggested that providing comprehensive sarcopenia screening and active prevention for the older people with cognitive decline has certain clinical value for improving the quality of life of the older people.