Association Between Sarcopenia and Quality of Life in Patients with Early Dementia and Mild Cognitive Impairment

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.

Do physical fitness and cognitive function mediate the relationship between basic activities of daily living and quality of life in older adults with dementia?

PURPOSE

Independence in activities of daily living (ADLs) is associated with quality of life (QoL) in individuals with dementia. However, the contribution of physical and cognitive functions to this relationship needs further examination. This study aims to examine the mediating effect of physical fitness and cognitive function in the relationship between independence in basic ADLs and QoL among older adults with dementia.

METHODS

This cross-sectional study included 107 older adults with dementia (74.8% women; age 78.21 ± 7.70 years). Independence in basic ADL and QoL were evaluated using the Barthel Index (BI) and QoL- Alzheimer's Disease Scale, respectively. The Alzheimer's Disease Assessment Scale-Cognitive Subscale and the Mini-Mental State Examination were applied to assess cognitive function. Physical fitness was evaluated using the 30-s chair stand, 2-min step and the Timed-Up and Go tests. A structural equation modelling (SEM) with bootstrapping estimation was conducted to determine the relationship between all variables.

RESULTS

Independence in basic ADL positively affected QoL and this association was mediated by physical fitness (β = 0.242, p = 0.011). No statistically significant results were observed when testing cognitive function as a mediator between BI and QoL (β = 0.009, p = 0.345).

CONCLUSIONS

Physical fitness (i.e., lower body strength, aerobic capacity, and mobility) plays a role in the relationship between basic ADL independence and QoL of older adults with dementia, reinforcing the need to improve and monitor these parameters throughout the disease progression. Future longitudinal studies should explore the temporal relationship between physical and cognitive function and its contribution to basic ADL independence and QoL.

How long were older people expected to live with or without sarcopenia? Multistate modeling of a national cohort study

Objectives

Sarcopenia is well known to be associated with mortality, but there is a lack of evidence on the estimates of life expectancy (LE) for sarcopenia in China. This study aims to estimate total life expectancy (TLE) and sarcopenia-specific LE in community-dwelling older Chinese adults with and without sarcopenia.

Methods

This study included participants aged 60 years and older who enrolled in the cohort in 2011 and 2013 and at least completed one follow-up until 2015 as part of the China Health and Retirement Longitudinal Study (CHARLS). The criteria for defining sarcopenia were based on the guidelines established by the Asian Working Group on Sarcopenia in 2019. TLE and sarcopenia-specific LE were estimated for the total population and subgroups using continuous-time multistate modeling.

Results

A total of 6,029 participants (49.2% women) with an average age of 68.4 (SD: 6.56) years were included in the study. The baseline prevalence of sarcopenia and possible sarcopenia was 19.5 and 44.9%, respectively. We observed that sarcopenia stages naturally deteriorated to worse stages (including death, by 24.4%) and returned to better stages (17.1%) during a median follow-up of 3.92 years (IQR: 2.00 ~ 4.00). The average TLE at the age of 60 was 20.9 [95% CI: 20.2-21.5] years (22.1 [95% CI: 19.6-24.6] for non-sarcopenic older adults, 20.9 [95% CI: 19.5-22.3] for possible sarcopenic, and 18.7 [95% CI: 16.4-21.1] for sarcopenic). Men, former and current smokers, and those living in northwest China had less TLE. Sarcopenic older adults, those with lower education, those who are unmarried, those with agriculture hukou, and those living in rural and northwest China were expected to live fewer years with non-sarcopenia. Sarcopenic older people, men, those with agriculture hukou, and those living in rural and southwest China were expected to live more years with sarcopenia.

Discussion

The results improved our understanding of the relationship between sarcopenia and life expectancy. We suggested that targeted strategies should be considered in high-risk populations and underdeveloped regions to prevent sarcopenia and improve non-sarcopenic life years for the older population.

Ultrasonographic/regional muscle measurements for diagnosing sarcopenia in older adults with and without dementia

BACKGROUND

Sarcopenia and dementia are growing concerns among older adults that muscle and brain atrophy may cooccur. We aimed to compare the age-related loss of muscle mass by using ultrasound (US), and skeletal muscle mass index (SMI) by bioelectrical impedance analysis in older adults with and without dementia.

METHODS

A total of 221 older adults aged ≥65 years were included in the study. The diagnosis of sarcopenia was established if low muscle mass according to either SMI or sonographic gastrocnemius (GC) muscle thickness was combined with low grip strength. The diagnosis of dementia was based on the National Institute of Aging and Alzheimer's Association criteria and the major neurocognitive disorder definition in the Diagnostic and Statistical Manual of Mental Disorders-V. Muscle strength was measured by hand dynamometer and physical performance was assessed by 4-meter usual gait speed.

RESULTS

There were similar/moderate correlation coefficients between GC muscle thickness and SMI with functional parameters (all p < 0.01). Forty-six patients (20.8%) had dementia, and 21 (45.7%) of them had sarcopenia diagnosed by GC thickness (p < 0.001). Age was older but weight, body mass index, and all sarcopenia-related parameters were lower in dementia patients (all p < 0.01). When clinical variables were taken into binary logistic regression analyses, age [OR = 1.095 (95% CI: 1.028-1.167)], weight [OR = 0.918 (95% CI: 0.887-0.950)], and presence of dementia [OR = 5.109 (95% CI: 2.002-13.033)] were independently associated with sarcopenia diagnosed with GC muscle thickness (all p < 0.05).

DISCUSSION

This study showed that sarcopenia is highly prevalent in older adults with dementia (45.7%) than without dementia (11.4%). Amongst different factors, increased age, having low body weight, and the presence of dementia independently increased the risk of sarcopenia diagnosed by GC muscle thickness (but not diagnosed by SMI) in older adults. Thus, we can evaluate easily and successfully the loss of (regional) muscle mass in dementia patients by using US in outpatient clinics.

Assessing the psychometric performance of EQ-5D-5L in dementia: a systematic review

BACKGROUND

EQ-5D is widely used for valuing changes in quality of life for economic evaluation of interventions for people with dementia. There are concerns about EQ-5D-3L in terms of content validity, poor inter-rater agreement and reliability in the presence of cognitive impairment, but there is also evidence to support its use with this population. An evidence gap remains regarding the psychometric properties of EQ-5D-5L.

OBJECTIVES

To report psychometric evidence around EQ-5D-5L in people with dementia.

METHODS

A systematic review identified primary studies reporting psychometric properties of EQ-5D-5L in people with dementia. Searches were completed up to November 2020. Study selection, data extraction and quality assessment were undertaken independently by at least 2 researchers.

RESULTS

Evidence was extracted from 20 articles from 14 unique studies covering a range of dementia severity. Evidence of known group validity from 5 of 7 studies indicated that EQ-5D-5L distinguishes severity of disease measured by cognitive impairment, depression, level of dependence and pain. Convergent validity (9 studies) showed statistically significant correlations of weak and moderate strengths, between EQ-5D-5L scores and scores on other key measures. Statistically significant change was observed in only one of 6 papers that allowed this property to be examined. All seven studies showed a lack of inter-rater reliability between self and proxy reports with the former reporting higher EQ-5D-5L scores than those provided by proxies. Five of ten studies found EQ-5D-5L to be acceptable, assessed by whether the measure could be completed by the PwD and/or by the amount of missing data. As dementia severity increased, the feasibility of self-completing EQ-5D-5L decreased. Three papers reported on ceiling effects, two found some evidence in support of ceiling effects, and one did not.

CONCLUSIONS

EQ-5D-5L seems to capture the health of people with dementia on the basis of known-group validity and convergent validity, but evidence is inconclusive regarding the responsiveness of EQ-5D-5L. As disease progresses, the ability to self-complete EQ-5D-5L is diminished.

Impact of Sarcopenia on Decline in Quality of Life in Older People with Mild Cognitive Impairment

Quality of life (QOL) was assessed using the EQ-5D twice in 1 year in 57 older community-dwelling people (age 79.1±5.9 years) with mild cognitive impairment in a memory clinic. Screening for sarcopenia at the initial assessment revealed 40.1% of participants (23/57) were sarcopenic. QOL declined in 33.3% of participants (19/57) after around 1 year. Multiple logistic regression analysis showed that sarcopenia was associated with a decline in QOL around 1 year after initial assessment. Sarcopenia may be a risk factor for decline in QOL in older people with mild cognitive impairment.

Spanish translation, cultural adaptation and validation of the SarQoL®: a specific health-related quality of life questionnaire for sarcopenia

BACKGROUND

In 2015, a specific health-related quality of life questionnaire for sarcopenia, SarQoL®, was developed and validated in French. Since then, SarQoL® has been adapted and validated in different languages. We prepared a translation, cultural adaptation and validation of the psychometric properties of the SarQoL® into Spanish.

METHODS

A cross-sectional study with 86 participants. The translation and adaptation followed international guidelines with two direct translations, a synthesized version of the direct translations, two reverse translations, consensus by an expert committee of a pre-final version, pre-test by end users and final version. The discriminative power (logistic regression analyses), construct validity (Pearson and Spearman´s correlation), internal consistency (Cronbach´s alpha coefficient), test-retest reliability (intraclass correlation coefficient) and ceiling and floor effects were analyzed.

RESULTS

The Spanish version showed good construct validity (high correlation with comparable domains of the SF-36), high internal consistency (Cronbach's alpha coefficient: 0.84) and excellent test-retest reliability (ICC: 0.967, 95%, CI 0.917 - 0.989). However, it had no discriminative power between sarcopenic and non-sarcopenic participants defined with the EWGSOP and FNIH diagnostic criteria of sarcopenia. It did show discriminative power between patients with decreased vs normal muscle strength (54.9 vs. 62.6, p 0.009) and low vs. normal physical performance (57.3 vs. 70.2; p 0.005). No ceiling or floor effect was found.

CONCLUSIONS

The Spanish version of SarQoL® has similar psychometric properties to those of the original version of the instrument. It did not discriminate between sarcopenic and non-sarcopenic patients diagnosed according to the EWGSOP or FNIH criteria, but it did with those with low muscle strength and low physical performance.

Sarcopenia reduces quality of life in the long-term: longitudinal analyses from the English longitudinal study of ageing

Aim

To examine the association between sarcopenia at baseline and changes in quality of life at 10 years follow-up in a large representative sample of older English adults.

Findings

After considering numerous confounders, sarcopenia at baseline was associated with a higher incidence of poor quality of life. People having sarcopenia at baseline reported significantly lower values in CASP-19 after ten years of follow-up.

Message

Sarcopenia is an important and independent risk factor for poor quality of life in older people.

Purpose

Mixed findings exist for sarcopenia/quality of life (QoL) relationship. Moreover, the majority of studies in this area have utilized a cross-sectional design or specific clinical populations. Therefore, the aim of the present study was to examine the association between sarcopenia at baseline and QoL at 10 years follow-up in a large representative sample of older English adults.

Methods

Sarcopenia was diagnosed as having low handgrip strength and low skeletal muscle mass index. QoL was measured using the CASP (control, autonomy, self-realisation and pleasure)-19, with higher values reflecting higher QoL. Multivariable logistic regression analysis was conducted to assess prospective associations between sarcopenia at baseline and poor QoL at follow-up; generalized linear model with repeated measures was used for reporting mean changes during follow-up between sarcopenia and not.

Results

Among 4044 older participants initially included at baseline (mean age: 70.7 years; 55.1% females), 376 had sarcopenia. In the multivariable analysis, after adjusting for several potential confounders, sarcopenia at baseline was associated with a higher incidence of poor QoL (odds ratio, OR = 5.82; 95% confidence interval, CI 3.45–9.82). After matching for QoL values at baseline and adjusting for potential confounders, people with sarcopenia reported significantly lower values in CASP-19 (mean difference = − 3.94; 95% CI − 4.77 to − 3.10).

Conclusions

In this large representative sample of older English adults, it was observed that sarcopenia at baseline was associated with worse scores of QoL at follow-up compared to those without sarcopenia at baseline. It may be prudent to target those with sarcopenia to improve QoL.

Nutritional status mediates the relationship between sarcopenia and cognitive impairment: findings from the WCHAT study

Background

Sarcopenia is associated with cognitive impairment in older adults. However, the underlying mechanisms are not fully understood.

Aim

To explore the mediating role of nutritional status in the relationship between sarcopenia and cognitive impairment.

Methods

Three thousand eight hundred and ten participants (mean age 61.94 ± 8.01 years) from the West China Health and Aging Trend (WCHAT) study were included. We defined sarcopenia using the Asian Working Group for Sarcopenia (AWGS) 2019 criteria. Cognitive status and nutritional status were measured using the Short Portable Mental Status Questionnaire (SPMSQ) and the Mini Nutritional Assessment Short Form (MNA-SF). Relationships between sarcopenia, nutritional status, and cognitive function were explored using multiple linear regression. Two mediation models were generated to examine whether nutritional status mediates the association between sarcopenia and cognitive function using PROCESS macro version 3.5.

Results

The study involved 3147 (82.6%) non-sarcopenic, 387 (10.2%) sarcopenic, and 276 (7.2%) severely sarcopenic individuals. In mediation model 1, sarcopenia (β = 0.208, 95% CI 0.072 to 0.344, P = 0.0028) was significantly associated with cognitive impairment, and nutritional status mediated this association (indirect effect = 0.162, bootstrap 95% CI 0.116 to 0.212). Mediation model 2 indicated that nutritional status exhibited a full mediating effect regarding the association between sarcopenia and cognitive impairment (indirect effect = 0.131, bootstrap 95% CI: 0.08 to 0.188; direct effect = 0.046, bootstrap 95% CI − 0.115 to 0.21) and a partial mediating effect regarding the association between severe sarcopenia and cognitive impairment (indirect effect = 0.21, bootstrap 95% CI: 0.143 to 0.283; direct effect = 0.476, bootstrap 95% CI: 0.234–0.724).

Conclusions

The relationship between sarcopenia and cognitive impairment was significantly mediated by nutritional status. Early nutritional interventions may prevent cognitive decline in sarcopenic older adults.

Health-related physical indicators and self-rated quality of life in older adults with neurocognitive disorder

PURPOSE

This study aimed to identify the association between health-related physical indicators-sarcopenia-related factors, physical fitness, independence in activities of daily living (ADL) and habitual physical activity-and self-rated quality of life (QoL) in people with neurocognitive disorder (NCD).

METHODS

This cross-sectional study included 115 participants (78.22 ± 7.48 years; 74.8% female) clinically diagnosed with NCD. Self-rated QoL was evaluated using The Quality of Life-Alzheimer's Disease (QoL-AD). Dual energy X-ray Absorptiometry, handgrip strength, Short Physical Performance Battery, and the 6-m Walk test were used to assess sarcopenia-related factors. Senior Fitness Test and One Leg Balance test, Barthel Index, Baecke Modified Habitual Physical Activity Questionnaire were used to determine physical fitness, independence in ADL and physical activity, respectively. Regressions analyses were performed to examine associations between these variables and QoL-AD.

RESULTS

Data from univariable linear regression analysis revealed that self-rated QoL was associated with sarcopenia-related factors (lower body function, handgrip strength, gait speed, and appendicular skeletal muscle mass index-ASMI), physical fitness (upper-and-lower-body strength, agility/dynamic balance, cardiorespiratory fitness and body mass index), habitual physical activity and independence in ADL. Results from multivariable regression analysis showed that ASMI (B = 1.846, 95% CI 0.165-3.527, p = 0.032) and lower body function (B = 0.756, 95% CI 0.269-1.242, p = 0.003) were positively associated with self-rated QoL. These variables explained 20.1% of the variability seen in self-rated QoL, controlling for age, sex, marital status and education.

CONCLUSION

Sarcopenia-related factors, namely lower body function and ASMI, should be acknowledged in future research studies as critical health-related indicators associated with QoL in people with NCD.

TRIAL REGISTRATION

ClinicalTrials.gov-identifier number NCT04095962.