Motoric Cognitive Risk Syndrome in a Chinese Older Adult Population: Prevalence and Associated Factors

Development and validation of a risk prediction model for motoric cognitive risk syndrome in older adults

OBJECTIVE

The objective of this study was to develop a risk prediction model for motoric cognitive risk syndrome (MCR) in older adults.

METHODS

Participants were selected from the 2015 China Health and Retirement Longitudinal Study database and randomly assigned to the training group and the validation group, with proportions of 70% and 30%, respectively. LASSO regression analysis was used to screen the predictors. Then, identified predictors were included in multivariate logistic regression analysis and used to construct model nomogram. The performance of the model was evaluated by area under the receiver operating characteristic (ROC) curve (AUC), calibration curves and decision curve analysis (DCA).

RESULTS

528 out of 3962 participants (13.3%) developed MCR. Multivariate logistic regression analysis showed that weakness, chronic pain, limb dysfunction score, visual acuity score and Five-Times-Sit-To-Stand test were predictors of MCR in older adults. Using these factors, a nomogram model was constructed. The AUC values for the training and validation sets of the predictive model were 0.735 (95% CI = 0.708-0.763) and 0.745 (95% CI = 0.705-0.785), respectively.

CONCLUSION

The nomogram constructed in this study is a useful tool for assessing the risk of MCR in older adults, which can help clinicians identify individuals at high risk.

The clinical characteristics of cerebral small vessel disease patients with motoric cognitive risk syndrome during single- and dual-task walking

Objective

We aimed to (1) identify neuroimaging biomarkers of distinguishing motoric cognitive risk syndrome (MCRS) risk among older Chinese adults with cerebral small vessel disease (CSVD) and (2) detect differences in gait parameters and neuroimaging biomarkers between CSVD individual with and without MCRS, especially during dual-task walking (DTW).

Methods

We enrolled 126 inpatients with CSVD who were divided into two groups according to MCRS status. Data on basic parameters, variability, asymmetry, and coordination were collected during single-task walking (STW) and DTW. Neuroimaging features (white matter hyperintensities, lacunes, and microbleeds) and total disease burden were calculated. Analysis of variance and logistic regression analyses were applied to assess the role of STW, DTW, and neuroimaging biomarkers in MCRS.

Results

In total, 126 consecutive inpatients with CSVD were included (84 and 42 patients were classified as MCRS-negative and MCRS-positive, respectively). The MCRS-positive group showed poorer performance for nearly all gait parameters compared with the MCRS-negative group during cognitive DTW. Meanwhile, all gait parameters except asymmetry were assessed in participants with MCRS for significant deterioration during cognitive DTW compared with that during STW. However, only basic parameters differed between STW and cognitive DTW in participants without MCRS. A significant independent association between total CSVD scores and MCRS was also detected.

Conclusions

For CSVD patients, with higher total CSVD burden rather than any single neuroimaging marker, was linked to a greater risk of MCRS. In addition, CSVD individuals with MCRS had higher variability and phase coordination index (PCI), especially in cognitive DTW. Thus, they should concentrate more on their gait variability or coordination and reduce secondary task loads while walking in daily life, especially in cognitive secondary tasks.

Association between Perceived Stress and Motoric Cognitive Risk Syndrome in an Elderly Population: Rugao Longevity and Aging Study

INTRODUCTION

Previous studies have indicated a correlation between perceived stress and cognitive decline. However, it remains unknown whether high levels of perceived stress can result in motoric cognitive risk (MCR) syndrome. This study investigated the relationship between perceived stress and MCR in a community-based population.

METHODS

The study cohort comprised 852 elderly individuals from the Rugao Longitudinal Aging Cohort. Perceived stress was assessed using the 10-item Perceived Stress Scale (PSS-10), while MCR was defined as the coexistence of subjective memory complaints (SMCs) and slow gait speed.

RESULTS

The average age of the study participants is 79.84 ± 4.34 years. The mean score of PSS-10 among participants is 10.32 (range = 0-33; [SD] = 5.71), with a median score of 10.00 (6.00, 14.00). The prevalence of MCR is 9.3%. In the logistic regression analysis, for each 1-SD (5.71) increase in the global PSS-10 score, the risk of MCR increased by 40% (95% CI 1.09-1.80). Additionally, in the aspect of two components of MCR, with a 1-SD increase (5.71) in the global PSS-10 score, there was a 50% (95% CI 1.29-1.75) increase in the risk of SMCs and a 27% (95% CI 1.04-1.55) increase in the risk of slow gait speed. In terms of specific walking speed, there was a reverse correlation between the global PSS-10 score and walking speed (r = -0.14, p < 0.001).

CONCLUSIONS

This study provided preliminary evidence that high levels of perceived stress were associated with the risk of MCR in a community-dwelling population.

Association of multimorbidity patterns with motoric cognitive risk syndrome among older adults: Evidence from a China longitudinal study

OBJECTIVES

Motoric cognitive risk syndrome (MCR), a pre-dementia syndrome, is characterized by slow gait and subjective cognitive complaints among older adults. This study assessed the relationship between multimorbidity, its patterns, and MCR.

METHODS

Data for this study were obtained from three waves (2011, 2013, and 2015) of the China Health and Retirement Longitudinal Study. Participants who were aged 60 years and older and had complete data at baseline as well as complete data about MCR at follow-up were selected. Patients without MCR at baseline were selected for further analyses. Longitudinal associations between multimorbidity, its patterns, and MCR were examined using a Cox proportional hazards model. Multimorbidity patterns were classified using latent class analysis.

RESULTS

A total of 4923 respondents were included at baseline, 43.47% of whom had multimorbidity. Additionally, the prevalence of MCR at baseline was 12.61%. After adjusting for covariates, multimorbidity was positively associated with MCR (hazard ratio [HR] = 1.33, 95% confidence interval [CI] = 1.06-1.68). A higher number of multimorbidity was also significantly associated with an increased risk of developing MCR (HR = 1.10, 95% CI = 1.02-1.19). Three multimorbidity patterns were selected: relatively healthy pattern, respiratory pattern, and cardiovascular pattern. Older adults with the cardiovascular pattern were 1.57 times more likely to develop MCR than those with the relatively healthy pattern (HR = 1.57, 95% CI = 1.16-2.13). There was no significant difference between the relatively healthy pattern and the respiratory pattern (HR = 1.31, 95% CI = 0.91-1.92).

CONCLUSIONS

MCR is highly prevalent among older Chinese adults. MCR may be exacerbated by multimorbidity. For older adults with multimorbidity (especially cardiovascular multimorbidity), attention should be paid to MCR to achieve early detection, diagnosis, and treatment.

[Motoric cognitive risk syndrome-Setting the course for dementia prevention?]

BACKGROUND

The predicted increase in adults with dementia will pose a major challenge for the German healthcare system. To mitigate this challenge, the early detection of adults with an increased risk of dementia is crucial. In this context, the concept of motoric cognitive risk (MCR) syndrome has been introduced into the English literature but is currently relatively unknown in German-speaking countries.

OBJECTIVE

What are the characteristics and diagnostic criteria of MCR? What is the impact of MCR on health-related parameters? What is the current state of evidence regarding the risk factors and prevention of the MCR?

MATERIAL AND METHODS

We reviewed the English language literature concerning MCR, the associated risk factors, and protective factors, similarities or differences with the concept of mild cognitive impairment (MCI), and its influence on the central nervous system.

RESULTS

The MCR syndrome is characterized by subjective cognitive impairment and a slower gait speed. Compared to healthy adults, adults with the MCR have a higher risk of dementia, falls, and mortality. Modifiable risk factors provide a starting point for specific multimodal lifestyle-related preventive interventions.

CONCLUSION

As MCR can be easily diagnosed in practical settings, it could become an important concept for the early detection of adults with an increased risk of dementia in German-speaking countries, although further research is necessary to empirically confirm this assumption.

Association of Motoric Cognitive Risk Syndrome with Sarcopenia and Systemic Inflammation in Pre-Frail Older Adults

Motoric cognitive risk syndrome (MCR) is defined by the presence of slow gait and subjective cognitive decline. It is well recognized as a prodrome for dementia, but the biological mechanism and trajectory for MCR are still lacking. The objective of this study was to explore the association of MCR with body composition, including sarcopenia and systemic inflammation, in pre-frail older adults in a cross-sectional study of 397 pre-frail community-dwelling older adults. Data on demographics, physical function, frailty, cognition (Montreal Cognitive Assessment (MoCA)), perceived health and depression were collected. Body composition was measured using a bioelectrical impedance analyzer. Systemic inflammatory biomarkers, such as progranulin, growth differentiation factor-15 (GDF-15), interleukin-10 (IL-10), interleukin-6 and tumor necrosis factor-α (TNF-α), were collected. Univariate and multivariate logistic regression were used to analyze the association between MCR, body composition, sarcopenia and systemic inflammatory biomarkers. The prevalence of MCR was 14.9%. They were significantly older and there were more females, depression, functional impairment, lower education, physical activity and MoCA scores. Body fat percentage (BF%), fat mass index, fat to fat free mass ratio (FM/FFM) and sarcopenia prevalence were significantly higher in MCR. Serum GDF-15 and TNF-α levels were highest with progranulin/TNF-α and IL-10/TNF-α ratio lowest in MCR. Compared to healthy patients, MCR was significantly associated with sarcopenia (aOR 2.62; 95% CI 1.46-3.17), BF% (aOR 1.06; 95% CI 1.01-1.12), FMI (aOR 1.16; 95% CI 1.02-1.30) and FM/FFM (aOR 6.38; 95% CI 1.20-33.98). The association of IL-10 to TNF-α ratio (aOR 0.98, 95% CI 0.97-0.99) and IL-10 (aOR 2.22, 95% CI 0.05-0.98) with MCR were independent of sarcopenia and BF%. Longitudinal population studies are needed to understand the role of body fat indices and IL-10 in pre-frail older adults with MCR and trajectory to dementia.

Association between positive control in self-perceptions of aging and motoric cognitive risk syndrome among Chinese community-dwelling older adults: a cross-sectional study

BACKGROUND

Self-perceptions of aging (SPA) are important psychosocial factors that lead to a wide range of outcomes including dementia. However, the relationships between positive SPA and motoric cognitive risk syndrome (MCR) which is a predementia syndrome are still unknown. This study aimed to reveal the associations of positive control and aging awareness of SPA with the risk of MCR and its components.

METHODS

A cross-sectional design was conducted among 1137 Chinese community-dwelling older adults. Positive control and aging awareness were defined by two dimensions of SPA (Positive control and Timeline chronic). MCR was determined according to definition. Multivariable logistic regression was used to examine the associations.

RESULTS

The overall prevalence of MCR was 11.5% (mean age = 71.62 ± 5.22). After adjusting for depression, anxiety, and cognitive function, positive control was associated with reduced risk of MCR (OR = 0.624, 95% CI 0.402-0.969, P = 0.036), subjective cognitive complaints (SCC) (OR = 0.687, 95% CI 0.492-0.959, P = 0.027), and gait speed (GS) (OR = 0.377, 95% CI 0.197-0.720, P = 0.003), respectively. Aging awareness was merely related to increased risk of MCR (OR = 1.386, 95% CI 1.062-1.810, P = 0.016).

CONCLUSIONS

This study highlights the crucial associations of positive control and aging awareness with MCR and its components. Our results emphasize that positive belief in control and adaptive aging awareness might be promising targets for preventing MCR.

Motoric Cognitive Risk Syndrome Among Chinese Older Adults with White Matter Lesions: A Cross-Sectional Observational Study

Brain aging is characterized by the declines in motor and cognitive features. The present study is to detect motor cognitive risk syndrome (MCRS) in older adults with white matter lesions (WML). 134 WML aged patients were recruited and diagnosed with the criteria for MCRS. Numerous cognitive function tests and walking tests were performed. The frequency of MCRS is 28.35%. Verbal fluency test, Mini-Mental State Examination, and dual-task walking speed were independent risk factor of MCRS. These findings indicated that MCRS was common in WML seniors. MCRS was associated with the pathologies of WML in older adults.

Mediating effect of lower extremity muscle strength on the relationship between mobility and cognitive function in Chinese older adults: A cross-sectional study

Aging is a multifactorial process associated with irreversible decline in mobility and cognitive function. However, the mechanisms underlying the relationship between mobility and cognitive function remain elusive. In specific, the mediating effect of muscle strength, which is essential to maintain mobility, on this relationship has yet to be clarified. Accordingly, we performed a cross-sectional study involving Chinese older adults to understand the role of muscle strength in the relationship between mobility and cognitive function. The cognitive function and physical performance of 657 community-dwelling participants aged over 65 years old were observed. Cognitive function was assessed using the Mini-Mental State Examination, whereas physical performance, including mobility and muscle strength, was measured via Timed Up-and-Go Test and knee extension strength measurement. Data were statistically analyzed using PROCESS Model 4 developed by Hayes, and 595 complete data were finally included. Physical performance (mobility and muscle strength) was significantly correlated with cognitive function (p &lt; 0.01). Muscle strength was negatively correlated with mobility (r = −0.273, p &lt; 0.001) and positively correlated with cognitive function (r = 0.145, p &lt; 0.001). Muscle strength accounted for 20.1% of the total mediating effects on the relationship between mobility and cognitive function, which revealed the partial mediating role of lower extremity muscle strength in this relationship.

Prevalence and Correlates of Motoric Cognitive Risk Syndrome in Chinese Community-Dwelling Older Adults

Background: Motoric cognitive risk (MCR) syndrome is considered to be a pre-dementia syndrome. Although an increasing number of studies have begun to focus on this syndrome, few investigations have been launched in China. This study was performed to examine the prevalence and correlates of MCR in China.

Methods: We included 5,725 adults aged over 60 years from China Health and Retirement Longitudinal Study (CHARLS). MCR was defined as the presence of subjective cognitive complaints and a gait speed ≤20th percentile of the weighted population distribution adjusted for sex and height. The associations among selected modifiable associated factors and clinical measures with MCR were examined using multivariate logistic regression analysis.

Results: Of the participants, 414 met the criteria for MCR with an overall prevalence 7.29% (95% CI: 6.62–7.96%). MCR was found to be more prevalent among women than men (9.73 vs 4.85%), and more prevalent among participants ≥75 years than those &lt;75 years (7.85 vs 5.23%). After multivariable adjustment, lower or upper extremity functional limitations, activities of daily living (ADL) disabilities, weak grip strength, exhaustion, and history of hypertension were found to be significantly associated with MCR. The multivariate analysis also showed higher levels of cystatin C and C-reactive protein were associated with increased odds for MCR.

Conclusions: The present study showed that MCR syndrome is highly prevalent among Chinese community-dwelling older adults, and revealed several factors that were correlated with MCR. Longitudinal studies are warranted to further explore the modifiable risk factors of MCR.

The Flexibility of Physio-Cognitive Decline Syndrome: A Longitudinal Cohort Study

The mutual presence of impairments in physical and cognitive functions in older adults has been reported to predict incident disability, dementia, and mortality. The longitudinal transitions of phenotypes between these functional impairments, either individually or in combination, remain unclear. To investigate the natural course and prevalence of physical and/or cognitive impairments (CIs), we enrolled participants from a community-based population. Data were retrieved from the first (August 2011 and December 2012) and second wave (August 2013 and June 2015) of the I-Lan Longitudinal Aging Study (ILAS). All participants were classified into four groups: robust, mobility impairment (MI), CI, and physio-cognitive decline syndrome (PCDS). MI was diagnosed with weakness and/or slowness. CI was diagnosed if a subject met a cutoff below 1.5 standard deviations (SDs) of age-, sex-, and education-matched norms of any neuropsychological assessments. PCDS was combined with MI and CI. Our results showed that 38, 14, 30, and 18% of the participants were on the robust, MI, CI, and PCDS at the first wave, respectively. After 2.5 years, 17% robust, 29% MI, and 37% CI progressed to PCDS. In contrast, 33% of PCDS was reversed to non-PCDS. Predictors of conversion to PCDS included worse memory and language functions, older age, lower muscle mass, and the presence of diabetes. In PCDS, a stronger hand-grip strength, younger age, and better memory functions predicted reversion to non-PCDS status. In summary, we probed the transition of PCDS. The skeletal muscle mass/function and memory function are crucial factors associated with PCDS reversion or progression.

Association of Motoric Cognitive Risk Syndrome with Cardiovascular and Noncardiovascular Factors: A Systematic Review and Meta-Analysis

OBJECTIVES

Motoric cognitive risk syndrome (MCR) is a recently proposed predementia syndrome characterized by subjective cognitive impairment and slow gait. We aim to assess the cardiovascular and noncardiovascular factors associated with MCR.

DESIGN

Systematic review and meta-analysis.

SETTING AND PARTICIPANTS

Studies comparing patients with MCR to those without MCR, and identifying the factors associated with MCR.

METHODS

We used databases, including PubMed, Cochrane CENTRAL, and Embase, to identify studies evaluating the factors associated with MCR. Mean differences, odds ratios (ORs), risk ratios (RRs), and hazard ratios (HRs) with 95% CIs were calculated using Review Manager.

RESULTS

Meta-analysis revealed that all cardiovascular factors, including diabetes (21 studies; OR 1.50, 95% CI 1.37, 1.64), hypertension (21 studies; OR 1.20, 95% CI 1.08, 1.33), stroke (16 studies; OR 2.03, 95% CI 1.70, 2.42), heart disease (7 studies; OR 1.45, 95% CI 1.13, 1.86), coronary artery disease (5 studies; OR 1.49, 95% CI 1.16, 1.91), smoking (13 studies; OR 1.28, 95% CI 1.04, 1.58), and obesity (12 studies; OR 1.34, 95% CI 1.13, 1.59) were significantly higher in the MCR than the non-MCR group. Noncardiovascular factors, including age (22 studies; MD = 1.08, 95% CI 0.55, 1.61), education (8 studies; OR 2.04, 95% CI 1.28, 3.25), depression (17 studies; OR 2.19, 95% CI 1.65, 2.91), prior falls (9 studies; OR 1.45, 95% CI 1.17, 1.80), arthritis (6 studies; OR 1.35, 95% CI 1.07, 1.70), polypharmacy (5 studies; OR 1.65, 95% CI 1.07, 2.54), and sedentary lifestyle (11 studies; OR 2.00, 95% CI 1.59, 2.52), were significantly higher in the MCR than in the non-MCR group. Alcohol consumption (6 studies; OR 0.84, 95% CI 0.72, 0.98), however, favored the MCR over the non-MCR group. Additionally, there was no significant association of MCR with gender (22 studies; OR 1.04, 95% CI 0.94, 1.15) and cancer (3 studies; OR 2.39, 95% CI 0.69, 8.28). MCR was also significantly associated with an increased likelihood of incident dementia (5 studies; HR 2.84, 95% CI 1.77, 4.56; P < .001), incident cognitive impairment [2 studies; adjusted hazard ratio (aHR) 1.76, 95% CI 1.44, 2.15], incident falls (4 studies; RR 1.37, 95% CI 1.17, 1.60), and mortality (2 studies; aHR 1.58, 95% CI 1.35, 1.85).

CONCLUSIONS AND IMPLICATIONS

MCR syndrome was significantly associated with diabetes, hypertension, stroke, obesity, smoking, low education, sedentary lifestyle, and depression. Moreover, MCR significantly increased the risk of incident dementia, cognitive impairment, falls, and mortality.

Association Between Sleep and Motoric Cognitive Risk Syndrome Among Community-Dwelling Older Adults: Results From the China Health and Retirement Longitudinal Study

Background: Sleep is increasingly recognized as an important lifestyle contributor to health; however, its relationship with Motoric cognitive risk syndrome (MCR) is still unclear. The present study aimed to examine the associations between sleep duration, sleep quality, and MCR among community-dwelling Chinese older adults.

Methods: We recruited 5,387 participants aged ≥60 years from the China Health and Retirement Longitudinal Study (CHARLS). Sleep-related variables including night sleep duration and sleep quality were assessed via self-reported questionnaires. MCR syndrome was defined as cognitive complaints and slow gait speed without dementia or impaired mobility. Multivariate logistic regression analysis was performed to explore the associations between sleep-related variables and MCR after controlling for all potential confounders including demographic characteristics, lifestyle factors, and comorbidities.

Results: We found that sleep duration was significantly associated with MCR, and the multivariate-adjusted odds ratios (OR) were highest for those with the shortest (<6 h OR = 1.55, 95% CI = 1.18–2.04) and longest (≥10 h OR = 1.73, 95% CI = 1.03–2.91) sleep durations. Moreover, an increasing frequency of self-perceived poor sleep quality was significantly associated with MCR in the adjusted model (3–4 days OR = 1.58, 95% CI = 1.16–2.17; 5–7 days OR = 1.81, 95% CI = 1.37–2.40).

Conclusions: Our study indicated an inverted U-shaped association between night sleep duration and MCR. Poor sleep quality was also associated with higher odds of MCR in community-dwelling Chinese elders. Longitudinal studies with a larger population size are needed to establish causality in the future and further explore potential action mechanisms.

Prevalence and factors associated with motoric cognitive risk syndrome in community-dwelling older Chinese: a cross-sectional study

BACKGROUND AND PURPOSE

A recently proposed pre-dementia syndrome, motoric cognitive risk (MCR) syndrome, is characterized by cognitive complaints and slow gait, and increases the risk of dementia and mortality. The aim of the present study was to explore the prevalence of and factors associated with MCR syndrome in elderly community-dwelling Chinese subjects.

METHODS

The Ningbo Community Study on Aging recruited 953 Chinese community-dwelling participants aged ≥ 65 years from November 2016 to March 2017. Handgrip, Five-Times-Sit-to-Stand (FTSS) test time and body composition, as well as comprehensive geriatric evaluation, were measured as potentially independent factors associated with MCR syndrome.

RESULTS

The prevalence of MCR syndrome was 12.8% in men and 12.6% in women, and high prevalence of MCR syndrome was not associated with age or sex. Multiple logistic regression analysis by sex showed that a 1-SD increase in FTSS test time in males and females was associated with 45% (95% confidence intervals, 19-76; P < 0.01) and 20% (95% confidence intervals, 9-33; P < 0.01) higher risk of having MCR syndrome, respectively, whereas handgrip strength was inversely correlated with MCR syndrome in males [odds ratio (OR), 0.91; P = 0.02] but not females (P = 0.06). Moreover, the relationship of arm fat mass and MCR syndrome was statistically significant in both sexes (OR, 1.69-1.77), but leg fat mass was only associated with MCR syndrome (OR, 1.56; P = 0.02) in men.

CONCLUSIONS

Handgrip, FTSS test time and body composition were associated in a sex-specific manner with MCR syndrome in elderly community-dwelling Chinese subjects. Our results on MCR syndrome are novel and should be considered as important information in future studies.

Association between motoric cognitive risk syndrome and frailty among older Chinese adults

BACKGROUND

Motoric cognitive risk syndrome (MCR) is a newly proposed predementia syndrome incorporating subjective cognitive complaints and slow gait. Previous studies have reported that subjective cognitive complaints and slow gait are associated with frailty in cognitively unimpaired older adults, but little is known about the link between MCR and frailty in older adults. Therefore, the aim of the study was to explore the associations of MCR and its components with frailty in older Chinese adults.

METHODS

In an observational cross-sectional study, a total of 429 older adults aged 60 years and older were admitted to the geriatric department. According to MCR criteria, all participants were classified into 4 groups: 1) the MCR group; 2) the subjective cognitive complaints only group; 3) the slow gait only group; and 4) the healthy control group. Physical frailty was assessed by the Clinical Frailty Scale (CFS). Multivariate logistic regression analysis was used to examine the association between MCR and frailty in older adults.

RESULTS

The prevalence rates of subjective cognitive complaints, slow gait and MCR were 15.9, 10.0 and 4.0%, respectively. After adjusting for confounding variables, the logistic regression analysis showed that slow gait (odds ratio [OR]: 3.40, 95% confidence interval [CI]: 1.40-8.23, P = 0.007) and MCR (OR: 5.53, 95% CI: 1.46-20.89, P = 0.012) were independently associated with frailty, but subjective cognitive complaints were not.

CONCLUSIONS

MCR and slow gait were significantly associated with frailty in older Chinese adults. Further studies should prospectively determine the causal relationship between MCR and frailty.

Motoric Cognitive Risk Syndrome: A Risk Factor for Cognitive Impairment and Dementia in Different Populations

Changes in gait, especially decreased gait velocity, may be a harbinger of cognitive decline in aging. Motoric cognitive risk syndrome (MCR), a pre-dementia syndrome combining slow gait and cognitive complaints, is a powerful clinical tool used to identify older adults at a high risk of developing dementia. The mean prevalence of MCR worldwide, including in a Korean cohort, was around 10%. The reported risk factors for incident MCR include older age, low education, cardiovascular disease, obesity, physical inactivity, and depression. In addition to dementia, MCR is also a risk factor for other age-related adverse conditions such as falls, disability, frailty, and mortality. The use of MCR has advantages over other pre-dementia syndromes in being much simpler to implement and requires fewer resources. Identification of mechanisms responsible for MCR may help in developing interventions to reduce the growing burden of dementia and disability worldwide.