Frailty and brain changes in older adults without cognitive impairment: A scoping review

Little is known about changes in the brain associated with frailty, in particular, which brain areas could be related to frailty in older people without cognitive impairment. This scoping review mapped evidence on functional and/or structural brain changes in frail older adults without cognitive impairment. The methodology proposed by the JBI® was used in this study. The search in PubMed, PubMed PMC, BVS/BIREME, EBSCOHOST, Scopus, Web of Science, Embase, and PROQUEST was conducted up to January 2023. Studies included following the population, concepts, context and the screening and data extraction were performed by two independent reviewers. A total of 9,912 records were identified, 5,676 were duplicates and were excluded. The remaining articles were screened; 31 were read in full and 17 articles were included. The results showed that lesions in white matter hyperintensities, reduced volume of the hippocampus, cerebellum, middle frontal gyrus, low gray matter volume, cortical atrophy, decreased connectivity of the supplementary motor area, presence of amyloid-beta peptide (aβ) in the anterior and posterior putamen and precuneus regions were more frequently observed in frail older adults, compared with non-frail individuals. Studies have suggested that such findings may be of neurodegenerative or cerebrovascular origin. The identification of these brain alterations in frail older adults through neuroimaging studies contributes to our understanding of the underlying mechanisms of frailty. Such findings may have implications for the early detection of frailty and implementation of intervention strategies.

Association of multidimensional frailty and quality of life in middle-aged and older people with stroke: A cross-sectional study

OBJECTIVES

The aims of this study were to (i) compare the prevalence of multidimensional frailty in middle-aged and older people with stroke and to (ii) explore the relationship between multidimensional frailty and quality of life (QoL) in this patient population.

BACKGROUND

In recent years, stroke patients have become increasingly younger. As an important risk factor for stroke patients, frailty has gradually drawn research attention because of its multidimensional nature.

DESIGN

This study used a cross-sectional design.

METHODS

The study included 234 stroke patients aged 45 and older. Multidimensional frailty was defined as a holistic condition in which a person experiences losses in one or more domains of human functioning (physical, psychological and social) based on the Tilburg Frailty Indicator, and QoL was based on the short version of the Stroke-Specific Quality of Life Scale. Hierarchical regression was used to analyse the correlation factors of QoL. STROBE checklist guides the reporting of the manuscript.

RESULTS

A total of 128 (54.7%) participants had multidimensional frailty, 48 (44.5%) were middle aged and 80 (63.5%) were older adults. The overall QoL mean score of the participants was 47.86 ± 9.04. Multidimensional frailty was negatively correlated with QoL. Hierarchical regression analysis showed that multidimensional frailty could independently explain 14.6% of the variation in QoL in stroke patients.

CONCLUSIONS

Multidimensional frailty was prevalent in middle-aged and older people with stroke, and it was a significant factor associated with QoL in stroke patients.

RELEVANCE TO CLINICAL PRACTICE

This study emphasises the importance of the early identification of multidimensional frailty. And targeted interventions should be studied to prevent the occurrence of multidimensional frailty and thereby improve the QoL of patients.

PATIENT OR PUBLIC CONTRIBUTION/S

There are no patient or public contributions to this study.

The key role of depression and supramarginal gyrus in frailty: a cross-sectional study

Background

The age-related decrease in reserve and resistance to stressors is recognized as frailty, one of the most significant challenges identified in recent years. Despite a well-acknowledged association of frailty with cognitive impairment, depression, and gray matter morphology, no clear data are available regarding the nature of this relationship. This cross-sectional study aims to disentangle the role of the behavioral, neuropsychological, and neural components as predictors or moderators of frailty.

Methods

Ninety-six older adults (mean age = 75.49 ± 6.62) were consecutively enrolled and underwent a clinical and MRI (3 T) evaluation to assess frailty, physical activity, global cognitive level, depression, wellbeing, autonomy in daily living, cortical thickness, and subcortical volumes.

Results

Results showed a full mediation of depression on the link between cortical thickness and frailty, while the cognitive level showed no significant mediating role. In particular, left supramarginal thickness had a predicting role on depression, that in turn impacted frailty occurrence. Finally, handgrip weakness was an early key indicator of frailty in this study's cohort.

Conclusion

These data substantiate the role of depression in mediating the link between neural integrity of the supramarginal gyrus and frailty. In the complexity of frailty, handgrip weakness seems to be an early key indicator. These results are relevant for the design of rehabilitation interventions aimed at reversing the frail condition.

Associations of physical frailty with health outcomes and brain structure in 483 033 middle-aged and older adults: a population-based study from the UK Biobank

BACKGROUND

Physical frailty is a state of increased vulnerability to stressors and is associated with serious health issues. However, how frailty affects and is affected by numerous other factors, including mental health and brain structure, remains underexplored. We aimed to investigate the mutual effects of frailty and health using large, multidimensional data.

METHODS

For this population-based study, we used data from the UK Biobank to examine the pattern and direction of association between physical frailty and 325 health-related measures across multiple domains, using linear mixed-effect models and adjusting for numerous confounders. Participants were included if complete data were available for all five indicators of frailty, all covariates, and at least one health measure. We further examined the association between frailty and brain structure and the role of this association in mediating the relationship between frailty and health outcomes.

FINDINGS

483 033 participants aged 38-73 years were included in the study at baseline (between Dec 19, 2006, and Oct 1, 2010); at a median follow-up of 9 years (IQR 8-10), behavioural data were available for 46 501 participants and neuroimaging data for 40 210 participants. The severity of physical frailty was significantly associated with decreased cognitive performance (Cohen's d=0·025-0·162), increased early-life risks (d=0·026-0·111), unhealthy lifestyle (d=0·013-0·394), poor physical fitness (d=0·007-0·668), increased symptoms of poor mental health (d=0·032-0·607), severe environmental pollution (d=0·013-0·064), and adverse biochemical markers (d=0·025-0·198). Some associations were bidirectional, with the strongest effects on mental health measures. The severity of frailty correlated with increased total white matter hyperintensity and lower grey matter volume, particularly in subcortical regions (d=0·027-0·082), which significantly mediated the association between frailty and health-related outcomes, although the mediated effects were small.

INTERPRETATION

Physical frailty is associated with diverse unfavourable health-related outcomes, which can be mediated by differences in brain structure. Our findings offer a framework for guiding preventative strategies targeting both frailty and psychiatric disorders.

FUNDING

National Institute of Mental Health, National Science Foundation.

Multisystem physiological perspective of human frailty and its modulation by physical activity

"Frailty" is a term used to refer to a state characterized by enhanced vulnerability to, and impaired recovery from, stressors compared with a nonfrail state, which is increasingly viewed as a loss of resilience. With increasing life expectancy and the associated rise in years spent with physical frailty, there is a need to understand the clinical and physiological features of frailty and the factors driving it. We describe the clinical definitions of age-related frailty and their limitations in allowing us to understand the pathogenesis of this prevalent condition. Given that age-related frailty manifests in the form of functional declines such as poor balance, falls, and immobility, as an alternative we view frailty from a physiological viewpoint and describe what is known of the organ-based components of frailty, including adiposity, the brain, and neuromuscular, skeletal muscle, immune, and cardiovascular systems, as individual systems and as components in multisystem dysregulation. By doing so we aim to highlight current understanding of the physiological phenotype of frailty and reveal key knowledge gaps and potential mechanistic drivers of the trajectory to frailty. We also review the studies in humans that have intervened with exercise to reduce frailty. We conclude that more longitudinal and interventional clinical studies are required in older adults. Such observational studies should interrogate the progression from a nonfrail to a frail state, assessing individual elements of frailty to produce a deep physiological phenotype of the syndrome. The findings will identify mechanistic drivers of frailty and allow targeted interventions to diminish frailty progression.

Physical Frailty and Brain White Matter Abnormalities: The Atherosclerosis Risk in Communities Study

BACKGROUND

Physical frailty is associated with increased risk for dementia and other neurologic sequelae. However, the neurobiological changes underlying frailty and frailty risk remain unknown. We examined the association of cerebral white matter structure with current and future frailty.

METHODS

Atherosclerosis Risk in Communities Study Neurocognitive Study participants who underwent 3T brain MRI were included. Frailty status was classified according to the Fried criteria. Cerebral white matter integrity was defined using white matter hyperintensity (WMH) volume and microstructure, measured using diffusion tensor imaging fractional anisotropy (FA) and mean diffusivity (MD). Multivariable linear regression was used to relate baseline frailty to white matter structure; multivariable logistic regression was used to relate baseline white matter to frailty risk among participants nonfrail at baseline.

RESULTS

In the cross-sectional analysis (N = 1 754; mean age: 76 years), frailty was associated with greater WMH volume, lower FA, and greater MD. These associations remained consistent after excluding participants with a history of stroke or dementia. Among participants nonfrail at baseline who completed follow-up frailty assessment (N = 1 379; 6.6-year follow-up period), each standard deviation increase in WMH volume was associated with 1.46 higher odds of frailty at follow-up. Composite FA and MD measures were not associated with future frailty; however, secondary analyses found several significant white matter tract-specific associations with frailty risk.

CONCLUSION

The current study demonstrates a robust association of WMH volume with current and future frailty. Although measures of white matter microstructure were altered in frail individuals, these measures were not generally associated with progression from nonfrail to frail status.

Effect of Baduanjin exercise on cerebral blood flow and cognitive frailty in the community older adults with cognitive frailty: A randomized controlled trial

Objectives

Regular Baduanjin exercise training has been shown to be beneficial to the physical and cognitive health of older adults, but the underlying mechanisms remain to be investigated. This study examined the influence of Baduanjin on cerebral hemodynamics in community-dwelling older adults with cognitive frailty.

Design

Randomized controlled trial.

Methods

A total of 102 eligible participants were randomly allocated into the Baduanjin exercise intervention group (BEG) or usual physical activity control group (CG) for 24 weeks. Cerebral hemodynamic parameters of bilateral middle/anterior cerebral artery and basilar artery, cognitive ability and physical frailty were assessed using Transcranial Doppler (TCD), Montreal Cognitive Assessment (MoCA) and Edmonton Frailty Scale (EFS) at baseline and 24 weeks post-intervention.

Results

After 24 weeks intervention, the changes in peak systolic velocity (PSV), mean blood flow velocity (MBFV), and end diastolic velocity (EDV) in the right middle cerebral artery and basilar artery were better in the BEG than in the CG; the increase in MoCA scores and the decrease in EFS scores were significantly higher in the BEG than in the CG. Moreover, the interaction of exercise and time on those variables showed obvious significance.

Conclusions

The 24 weeks Baduanjin exercise training had a positive beneficial effect on cerebral blood flow in community-dwelling older adults with cognitive frailty. This may be a potential mechanism by which Baduanjin exercise improves the cognitive frailty in older adults.

Trial registration

Chinese Clinical Trial Registry, ChiCTR1800020341.

Date of registration

December 25, 2018, http://www.chictr.org.cn/showproj.aspx?proj=29846.

The Structural and Functional Correlates of Frailty in Persons With Human Immunodeficiency Virus

BACKGROUND

Persons with HIV (PWH) are at increased risk of frailty, a clinically recognizable state of increased vulnerability resulting from aging-associated decline in multiple physiologic systems. Frailty is often defined by the Fried criteria, which includes subjective and objective standards concerning health resiliency. However, these frailty metrics do not incorporate cognitive performance or neuroimaging measures.

METHODS

We compared structural (diffusion tensor imaging [DTI]) and functional (cerebral blood flow [CBF]) neuroimaging markers in PWH with frailty and cognitive performance. Virologically controlled PWH were dichotomized as either frail (≥3) or nonfrail (<3) using the Fried criteria. Cognitive Z-scores, both domain (executive, psychomotor speed, language, and memory) and global, were derived from a battery of tests. We identified three regions of reduced CBF, based on a voxel-wise comparison of frail PWH compared with nonfrail PWH. These clusters (bilateral frontal and posterior cingulate) were subsequently used as seed regions of interest (ROIs) for DTI probabilistic white matter tractography.

RESULTS

White matter integrity connecting the ROIs was significantly decreased in frail compared with nonfrail PWH. No differences in cognition were observed between frail and nonfrail PWH. However, reductions in white matter integrity among these ROIs was significantly associated with worse psychomotor speed and executive function across the entire cohort.

CONCLUSIONS

We conclude that frailty in PWH can lead to structural and functional brain changes, including subtle changes that are not detectable by standard neuropsychological tests. Multimodal neuroimaging in conjunction with frailty assessment could identify pathological brain changes observed in PWH.

Association of the prefrailty with global brain atrophy and white matter lesions among cognitively unimpaired older adults: the Nakajima study

Physical frailty has been associated with adverse outcomes such as dementia. However, the underlying structural brain abnormalities of physical frailty are unclear. We investigated the relationship between physical frailty and structural brain abnormalities in 670 cognitively unimpaired individuals (mean age 70.1 years). Total brain volume (TBV), hippocampal volume (HV), total white matter hypointensities volume (WMHV), and estimated total intracranial volume (eTIV) on the 3D T1-weighted images were automatically computed using FreeSurfer software. Participants were divided into two states of physical frailty (robust vs. prefrail) based on the revised Japanese version of the Cardiovascular Health Study criteria. The multivariable-adjusted mean values of the TBV-to-eTIV ratio was significantly decreased, whereas that of the WMHV-to-eTIV ratio was significantly increased in the prefrail group compared with the robust group. Slowness, one of the components of physical frailty, was significantly associated with reduced TBV-to-eTIV and HV-to-eTIV ratios, and slowness and weakness were significantly associated with an increased WMHV-to-eTIV ratio. Our results suggest that the prefrail state is significantly associated with global brain atrophy and white matter hypointensities. Furthermore, slowness was significantly associated with hippocampal atrophy.

Association between white matter alterations on diffusion tensor imaging and incidence of frailty in older adults with cardiometabolic diseases

Diffusion tensor imaging (DTI) can be used for the early detection of abnormal changes in the integrity of cerebral white matter tracts, and we have previously reported that these changes are associated with indices of early atherosclerotic lesions. Although these changes have been demonstrated to be associated with the incidence of frailty in older adults, no studies have investigated this relationship in patients at high risk for vascular disease. In this longitudinal study, we followed outpatients with cardiometabolic diseases for a maximum of 6 years (median, 3 years) and evaluated the association of baseline DTI data of seven white matter tracts with the incidence of frailty. The modified version of the Cardiovascular Health Study criteria and the Kihon Checklist were used as indices of frailty; fractional anisotropy (FA) and mean diffusivity (MD) were used as indices of white matter changes. Patients who developed frailty based on both indices had low FA and high MD in many of the tracts tested, with the most significant difference found in the MD of the anterior thalamic radiation (ATR). Cox proportional hazard model analysis revealed a significantly high risk of frailty defined by both indices in the groups with high MD values in the left ATR. Similar results were found in patients with diabetes mellitus but not in those without diabetes mellitus. Therefore, abnormalities in the integrity of the left ATR could be associated with the progression of frailty in older adults with cardiometabolic disease, particularly those with diabetes mellitus.

Association between the frailty index and vascular brain damage: The Treviso Dementia (TREDEM) registry

PURPOSE

An association between frailty and vascular brain damage (VBD) has been described in older adults. However, most studies have identified frailty according to the phenotypic model. It is less clear whether frailty, operationalized as an accumulation of health deficits, is associated with the presence and severity of VBD. The present study was therefore undertaken to verify whether a 50-item frailty index (FI) is related to VBD in a large and relatively unselected cohort of attendees of a memory clinic.

MATERIALS AND METHODS

The TREDEM (Treviso Dementia) registry includes retrospective observational data of 1584 participants. A modified FI was calculated from 50 variables comprising diseases, disability, behavioral disorders, and blood biochemistry. The presence and severity of VBD, including leukoaraiosis, lacunes, larger infarctions and the hierarchical vascular rating scale (HVRS), were determined based on brain computerized tomography imaging. Multiple logistic regression models were built according to the stepwise method.

RESULTS

Mean age of the 1584 participants was 79.6 ± 7.5 years and 1033 (65.2 %) were females. The average number of health deficits was 11.6 ± 6.2, corresponding to an FI of 0.23 ± 0.12 (range: 0.00-0.56). Each 0.01-point increase in the FI was associated with an increased probability of leukoaraiosis (+2.3 %) and severe leukoaraiosis (+5 %), lacunas in the basal ganglia (+1.73 %), occipital lobes (+2.7 %), parietal lobes (+3 %), frontal lobes (+3.6 %), temporal lobes (+4.2 %), and thalamus (+4.4 %). Moreover, an increase of 0.01 points in the FI was associated with a 3.1 % increase in the probability of HVRS score (≥2).

CONCLUSION

An FI based on routine clinical and laboratory variables was associated with the presence, degree, and some localizations of VBD in a population of older adults with cognitive decline. This frailty assessment tool may therefore be used to identify individuals at risk of developing cerebrovascular disease and, consequently, to implement strategies for vascular risk factor control.

Genetically predicted frailty index and risk of stroke and Alzheimer's disease

BACKGROUND AND PURPOSE

Previous studies have reported the association between frailty and stroke or Alzheimer's disease (AD). However, the causality remains unclear. The aim of the present study was to evaluate whether genetically predicted frailty is associated with the risk of stroke or AD by a Mendelian randomization (MR) study.

METHODS

Genetic variants associated with the frailty index (FI) were obtained from a large genome-wide association study (GWAS). Summary-level data for stroke and AD were adopted from the corresponding large GWAS of individuals of European ancestry. The inverse variance weighted method was used for estimating causal effects. Multivariable analysis was performed for further adjustment.

RESULTS

The present MR study indicated a suggestive association between genetically predicted FI and a higher risk of any stroke (odds ratio 1.360, 95% confidence interval 1.006-1.838, p = 0.046). Regarding the subtypes of stroke, genetically predicted FI was associated with a higher risk of large artery atherosclerosis stroke (LAS) (odds ratio 2.487, 95% confidence interval 1.282-4.826, p = 0.007). No causal links were identified between genetically predicted FI and any ischaemic stroke, intracranial haemorrhage, cardioembolic stroke, small artery stroke, AD or AD-by-proxy. Multivariable MR analysis indicated that the association of genetically predicted FI with LAS was attenuated after adjustment for inflammatory bowel disease (p = 0.114).

CONCLUSIONS

The MR study suggested that genetically predicted FI may be associated with an increased risk of any stroke. Subgroup analysis indicated a suggestive association between genetically predicted FI and the risk of LAS. The underlying mechanisms need further investigation.

Frailty is associated with cognitive decline independent of cerebral small vessel disease and brain atrophy

Background

To examine the effect of frailty on cognitive decline independent of cerebral small vessel disease (cSVD) and brain atrophy, and whether associations between neuropathology and cognition differed depending on frailty status.

Methods

The Tasmanian Study of Cognition and Gait was a population-based longitudinal cohort study with data collected at 3 phases from 2005 to 2012. Participants aged 60–85 were randomly selected from the electoral roll. Various data were used to operationalize a 36-item frailty index (FI) at baseline. Brain MRI was undertaken to obtain baseline measures of neuropathology. A neuropsychological battery was used to assess cognition at each time point. Generalized linear mixed models were used to examine the effect of frailty and MRI measures on cognition over time. The associations between MRI measures and cognition were explored after stratifying the sample by baseline frailty status. All analyses were adjusted for age, sex, and education.

Results

A total of 385 participants were included at baseline. The mean age was 72.5 years (standard deviation [SD] 7.0), 44% were female (n = 171). In fully adjusted linear mixed models, frailty (FI × time β −0.001, 95% confidence interval [CI] −0.003, −0.001, p = .03) was associated with decline in global cognition, independent of brain atrophy, and cSVD. The association between cSVD and global cognition was significant only in those with low levels of frailty (p = .03).

Conclusion

These findings suggest that frailty is an important factor in early cognitive dysfunction, and measuring frailty may prove useful to help identify future risk of cognitive decline.

Pre-Existing Frailty is Unrelated to Progression of Diffuse Subcortical Damage of Vascular Origin: A Longitudinal Prospective Study in Community-Dwelling Older Adults

Background:

Both frailty and white matter hyperintensities (WMH) of presumed vascular origin are associated with enhanced expression of inflammatory biomarkers. Therefore, it is possible that pre-existing frailty predisposes to WMH progression. However, this relationship has not been explored. This population-based longitudinal prospective study aimed to assess the impact of frailty on subsequent progression of WMH in community-dwelling older adults living in rural Ecuador.

Methods:

Participants of the Atahualpa Project Cohort received baseline frailty assessment and brain MRIs. Frailty was evaluated by means of the Edmonton Frail Scale (EFS). WMH were graded according to the modified Fazekas scale. Individuals who received a follow-up brain MRI were included. Poisson regression models were fitted to assess the differential rate of WMH progression according to EFS score, after adjusting for demographics, level of education, and cardiovascular risk factors.

Results:

The study included 263 individuals aged ≥60 years (mean age: 65.7 ± 6.2 years; 57% women). The mean EFS score at baseline was 4 ± 2.3 points. Follow-up MRIs after a median follow-up of 6.5 years showed WMH progression in 103 (39%) individuals. The EFS score at baseline was associated with WMH progression in unadjusted analysis (P = .006). However, significance was not achieved in a multivariate Poisson regression model adjusted for relevant covariates (IRR: 1.07; 95% C.I.: 0.97-1.18; P = .192).

Conclusions:

Study results do not support an independent relationship between frailty and WMH progression, adjusting for the confounding effect of aging.

Co-Occurrence of Geriatric Syndromes and Diseases in the General Population: Assessment of the Dimensions of Aging

OBJECTIVES

The co-occurrence of multiple medical or psycho-social conditions (geriatric syndromes (GS) and age-related diseases) is a growing concern in older people. Given the diversity of these conditions and their complex interactions, our aim was to determine whether they could be structured into synthetic dimensions in order to facilitate the management of multimorbidity.

DESIGN

The underlying structure of 10 GSs and 8 age-related diseases was identified using a multiple correspondence analysis (MCA), and confronted to subjective and objective health outcomes.

SETTING

community residents from Bordeaux City (France) older than 75 years in 2010.

PARTICIPANTS

630 adults aged 75+ years who lived in Bordeaux and participated in the 10-year follow-up of the Three-City study.

MEASUREMENTS

GSs included physical frailty, cognitive impairment and dementia, dependency, depressive symptoms, polymedication, thinness, falls, sensory deficit, social isolation, incontinence. Age-related diseases were cancer, cardiac diseases, peripheral vascular diseases, diabetes, hypertension, pulmonary diseases, osteoporosis, other chronic diseases. Association of the MCA-derived independent dimensions was assessed with 10-year visit subjective health and well-being, and with incident death and entry into institution during the remaining cohort follow-up.

RESULTS

Most of the participants (82%) had at least two age-related syndromes or diseases. The MCA structured the 18 conditions into three major dimensions: Degradation (D) driven by GS, Vascular (V), and Psychosocial (P) representing 68.7%, 7.4%, and 5.7% of the total variance, respectively. Dimension D was a strong predictor of future death and institutionalization. Dimensions D and P were strongly associated with current well-being.

CONCLUSIONS

This work confirmed that multimorbidity is very common among older adults, and demonstrated the essential role of GS as manifestations of aging, even more than age-related diseases.

Biological and Neuroimaging Markers as Predictors of 5-Year Incident Frailty in Older Adults: A Secondary Analysis of the MAPT Study

BACKGROUND

This study aims to investigate the predictive value of biological and neuroimaging markers to determine incident frailty among older people for a period of 5 years.

METHODS

We included 1394 adults aged 70 years and older from the Multidomain Alzheimer Preventive Trial, who were not frail at baseline (according to Fried's criteria) and who had at least 1 post-baseline measurement of frailty. Participants who progressed to frailty during the 5-year follow-up were categorized as "incident frailty" and those who remained non-frail were categorized as "without frailty." The differences of baseline biochemical factors (25-hydroxyvitamin D, homocysteine, omega-3 index, C-reactive protein), other biological markers (Apolipoprotein E genotypes, amyloid-β deposits), and neuroimaging data (gray matter volume, hippocampal volume, white matter hyperintensities) were compared between groups. Cox proportional hazard model was used to evaluate the associations between biomarkers and incident frailty.

RESULTS

A total of 195 participants (14.0%) became frail over 5 years. Although 25-hydroxyvitamin D deficiency, homocysteine levels, low-grade inflammation (persistently increased C-reactive protein 3-10 mg/L), gray matter, and hippocampal volume were significantly associated with incident frailty in unadjusted models, these associations disappeared after adjustment for age, sex, and other confounders. Omega-3 index was the sole marker that presented a trend of association with incident frailty (hazard ratio: 0.92; 95% confidence interval: 0.83-1.01; p = .082).

CONCLUSIONS

This study failed to identify biomarkers able to predict frailty incidence in community-dwelling older adults for a period of 5 years. Further longitudinal research with multiple measurements of biomarkers and frailty is needed to evaluate the long-term relationships between changes in biomarkers levels and frailty evolution.

The Association of White Matter Hyperintensities with Frailty in Patients with Very Mild to Moderate Alzheimer's Disease

BACKGROUND

Frailty, one of serious global health problems in the elderly, is a growing concern in patients with Alzheimer's disease (AD) because of its high prevalence in AD and its impact on the prognosis.

OBJECTIVE

To investigate the quantitative association between white matter hyperintensities (WMH) and frailty in AD.

METHODS

A total of 144 outpatients were included. All subjects were evaluated by using Korean version of the CERAD assessment battery and diagnosed very mild to moderate AD. WMH volume was calculated using automated segmentation analysis from the 3D MRI image and further partitioned according to the distance from the ventricular surface. Using the Korean Frailty Index, prefrailty was defined by the scores of 3 and 4 and frailty by the score of 5 and higher.

RESULTS

In total, 23.6%were frailty, 32.6%were pre-frailty, and 43.8%were classified as a robust group. The frailty group had higher WMH volume compared to the robust group (p = 0.02), and these trends remained significant after linear regression analyses. According to the subclassification of WMH, using the robust group as a reference, total WMH (OR = 6.297, p = 0.013, 95%CI = 1.463-27.114), juxtaventricular WMH (OR = 12.955, p = 0.014, 95%CI = 1.687-99.509), and periventricular WMH (OR = 3.382, p = 0.025, 95%CI = 1.163-9.8531) volumes were associated with frailty, but deep WMH volume was not.

CONCLUSIONS

A quarter of patients with very mild to moderate AD is suffering from frailty. Our study provides the evidence of a cross-sectional relationship between WMH volume and frailty, and there is a difference in the association between the subclassification of WMH volume and frailty.

White Matter Integrity Underlies the Physical-Cognitive Correlations in Subjective Cognitive Decline

Objective: Although previous studies postulated that physical and cognitive decline codeveloped in preclinical dementia, the interconnected relationship among subjective cognitive complaints (SCCs), objective cognitive performance, and physical activity remained hazy. We investigated the mediating roles of physical activity between subjective and objective cognition. Diffusion tensor imaging (DTI) was utilized to test our hypothesis that brain white matter microstructural changes underlie the physical-cognitive decline in subjective cognitive decline (SCD).

Methods: We enrolled cognitively normal older adults aged > 50 years in the Community Medicine Research Center of Keelung Chang Gung Memorial Hospital during 2017–2020. Regression models analyzed mediation effects of physical activity between subjective and objective cognition. The self-reported AD8 questionnaire assessed SCCs. The SCD group, defined by AD8 score ≥ 2, further underwent diffusion MRI scans. Those who agreed to record actigraphy also wore the SOMNOwatch™ for 72 h. Spearman's correlation coefficients evaluated the associations of diffusion indices with physical activity and cognitive performance.

Results: In 95 cognitively normal older adults, the AD8 score and the Montreal Cognitive Assessment (MoCA) score were mediated partially by the metabolic equivalent of the International Physical Activity Questionnaire-Short Form (IPAQ-SF MET) and fully by the sarcopenia score SARC-F. That is, the relation between SCCs and poorer cognitive performance was mediated by physical inactivity. The DTI analysis of 31 SCD participants found that the MoCA score correlated with mean diffusivity at bilateral inferior cerebellar peduncles and the pyramids segment of right corticospinal tract [p < 0.05, false discovery rate (FDR) corrected]. The IPAQ-SF MET was associated with fractional anisotropy (FA) at the right posterior corona radiata (PCR) (p < 0.05, FDR corrected). In 15 SCD participants who completed actigraphy recording, the patterns of physical activity in terms of intradaily variability and interdaily stability highly correlated with FA of bilateral PCR and left superior corona radiata (p < 0.05, FDR corrected).

Conclusions: This study addressed the role of physical activity in preclinical dementia. Physical inactivity mediated the relation between higher SCCs and poorer cognitive performance. The degeneration of specific white matter tracts underlay the co-development process of physical-cognitive decline in SCD.

Neuroimaging markers of chronic fatigue in older people: a narrative review

BACKGROUND

Chronic fatigue is a common symptom in older adults. Although some studies have attempted to identify the neuronal correlates of fatigue associated with chronic diseases, the scientific evidence is scarce regarding fatigue in older people not suffering from a specific disease.

AIMS

To gather available evidence of neuroimaging studies investigating the associations between fatigue and brain health in older adults out of the context of a specific disease, and to identify potential brain structures associated with this symptom.

METHODS

Studies considering exclusively patients with a specific disease and/or studies focusing on physiological mechanisms of acute fatigue induced by the realization of cognitive and physical tasks were excluded.

RESULTS

Very few studies on the associations of fatigue with neuroimaging markers are currently available. Fatigue was associated with reduced hippocampus volumes and with hippocampal amyloid deposition. Regarding the association between fatigue and the circuit of basal ganglia, putamen and thalamus were associated with physical fatigability, whereas amygdala and thalamus with mental fatigability. Very limited evidence about white matter integrity found that healthy individuals with high levels of fatigue had a greater total volume of leukoaraiosis.

CONCLUSION

This review suggests that hippocampus damage and potentially loss of function in basal ganglia networks could play a role on chronic fatigue during aging. Further studies are needed to assess the associations of fatigue with white matter alterations.

Prevalence and risk factors of frailty among people in rural areas: a systematic review and meta-analysis

OBJECTIVE

Older people in rural areas are possibly more frail due to the limited medical resources and lower socioeconomic status. Given the negative healthy outcomes caused by frailty, knowing the epidemiology of frailty in rural areas is of great importance. We tried to synthesise the existing evidences for the prevalence and risk factors of frailty in rural areas.

DESIGN

A systematic review and meta-analysis.

DATA SOURCES

PubMed, Embase, MEDLINE, Cochrane Library, Web of Science and Scopus were used to identify the articles from inception to 30 April 2019.

ELIGIBILITY CRITERIA

Observational studies providing cross-sectional data on the prevalence of frailty in rural elderly were extracted.

DATA EXTRACTION AND SYNTHESIS

Two independent investigators selected studies, extracted data and assessed the methodological quality of included studies. The pool prevalence of frailty was calculated by the random effects model and the OR and 95% CI were used to calculate the risk factors.

RESULTS

The literature search yielded 2219 articles, of which 23 met the study criteria and were included in this analysis. The pooled prevalence of frailty and pre-frailty were 18% (95% CI 15% to 21%, I²=98.5%, p<0.001) and 50% (95% CI 45% to 56%, I²=98.4%, p<0.001), respectively. The pooled frailty prevalence was 15% for the Fried Phenotype, 18% for the Frailty Index and 23% for other criteria. The pooled prevalence of frailty was 17% for males and 26% for females. The pooled prevalence of frailty was 17% in developing countries and 23% in developed countries. Age, cognitive impairment, depressive symptom, risk of malnutrition, activity of daily living (ADL) disability and poor self-perception of health were associated with frailty. There was no publication bias.

CONCLUSIONS

Frailty influences almost one in five older people in rural areas, and increasing age, cognitive impairment, depressive symptom, risk of malnutrition, ADL disability and poor self-perception of health were all risk factors for frailty. We should be cautious about the research results due to the heterogeneity between studies.

Functional Connectivity of the Supplementary Motor Network Is Associated with Fried's Modified Frailty Score in Older Adults

Frailty is a geriatric syndrome defined by coexistence of unintentional weight loss, low physical reserve, or activity and is associated with adverse health events. Neuroimaging studies reported structural white matter changes in frail patients. In the current study, we hypothesized that clinical frailty is associated also with functional changes in motion-related cortical areas, that is, (pre-)supplementary motor areas (SMA, pre-SMA). We expected that observed functional changes are related to motor-cognitive test performance. We studied a clinical sample of 143 cognitively healthy patients ≥65 years presenting for elective surgery, enrolled in the BioCog prospective multicentric cohort study on postoperative cognitive disorders. Participants underwent preoperative resting-state functional magnetic resonance imaging, motor-cognitive testing, and assessment of Fried's modified frailty criteria. We analyzed functional connectivity associations with frailty and motor-cognitive test performance. Clinically robust patients (N = 60) showed higher connectivity in the SMA network compared to frail (N = 13) and prefrail (N = 70) patients. No changes were found in the pre-SMA network. SMA connectivity correlated with motor speed (Trail-Making-Test A) and manual dexterity (Grooved Pegboard Test). Our results suggest that diminished functional connectivity of the SMA is an early correlate of functional decline in the older adults . The SMA may serve as a potential treatment target in frailty.

Ongoing Oscillatory Electrophysiological Alterations in Frail Older Adults: A MEG Study

Objective: The role of the central nervous system in the pathophysiology of frailty is controversial. We used magnetoencephalography (MEG) to search for abnormalities in the ongoing oscillatory neural activity of frail individuals without global cognitive impairment.

Methods: Fifty four older (≥70 years) and cognitively healthy (Mini-Mental State Examination ≥24) participants were classified as robust (0 criterion, n = 34) or frail (≥ 3 criteria, n = 20) following Fried's phenotype. Memory, language, attention, and executive function were assessed through well-validated neuropsychological tests. Every participant underwent a resting-state MEG and a T1-weighted magnetic resonance imaging scan. We performed MEG power spectral analyses to compare the electrophysiological profiles of frail and robust individuals. We used an ensemble learner to investigate the ability of MEG spectral power to discriminate frail from robust participants.

Results: We identified increased relative power in the frail group in the mu (p < 0.05) and sensorimotor (p < 0.05) frequencies across right sensorimotor, posterior parietal, and frontal regions. The ensemble learner discriminated frail from robust participants [area under the curve = 0.73 (95% CI = 0.49–0.98)]. Frail individuals performed significantly worse in the Trail Making Test, Digit Span Test (forward), Rey-Osterrieth Complex Figure, and Semantic Fluency Test.

Interpretation: Frail individuals without global cognitive impairment showed ongoing oscillatory alterations within brain regions associated with aspects of motor control, jointly to failures in executive function. Our results suggest that some physical manifestations of frailty might partly arise from failures in central structures relevant to sensorimotor and executive processing.

Frailty, MRI, and FDG-PET Measures in an Australian Memory Clinic Cohort

Given that the global population is aging, the number of age-related syndromes, such as frailty, is expected to rise in conjunction. Frailty is characterized by the loss of homeostatic reserve, rendering the individual vulnerable to poor health outcomes. Many biological mechanisms have been proposed to contribute to frailty. However, few studies have assessed the associations between frailty and brain diseases or neuroimaging biomarkers. Aims: The aims of this study were to measure the prevalence of frailty in a memory clinic and to examine associations between frailty and brain changes found on magnetic resonance imaging (MRI) and 18-F deoxyglucose (FDG) positron emission tomography (PET) in memory clinic attendees. Methods: A 54-items Frailty Index was retrospectively assessed for all clinic attendees from 2014. Frailty was defined as FI > 0.25. MR images were analyzed for stroke, cerebral small vessel disease [CSVD, including cerebral microbleeds (CMBs), cortical superficial siderosis (CSS), and white matter hyperintensity (WMH)], and neurodegenerative changes [MRI: mesial temporal atrophy (MTA), FDG-PET: regional hypometabolism], blind to clinical findings. Results: There were 209 clinic attendees in 2014, of whom 121 had MRI performed. The prevalence of frailty (using FI) in the memory clinic in 2014 was 38.3% overall (patients without MRI: 43.2%, patients with MRI 34.7%, p = 0.25). Frailty was associated with presence of deep WMH, increased severity of periventricular WMH, and presence of CSS, but not neurodegeneration markers (MTA atrophy/FDG-PET hypometabolism). Conclusion: The findings support the idea that previously reported associations between frailty and imaging evidence of CSVD in other cohorts are also relevant to the Australian clinic setting. Given that a large proportion of memory clinic attendees are frail, there may be opportunities for interventions to reduce preventable adverse health outcomes, such as falls and fractures, and reduce the prevalence and impact of frailty in this cohort.

Cross-Sectional Association Between Cognitive Frailty and White Matter Hyperintensity Among Memory Clinic Patients

BACKGROUND

Cognitive frailty (CF) is defined as simultaneous presence of physical frailty (PF) and cognitive impairment among older adults without dementia. Although white matter hyperintensities (WMH) as expressions of cerebral small vessel disease are associated with physical and cognitive decline and could manifest as CF, this association remains yet to be clarified.

OBJECTS

To clarify the association between CF and WMH among memory clinic patients.

METHODS

The subjects of this cross-sectional study were 121 cognitively normal (CN) and 212 mildly cognitively impaired (MCI) patients who presented to the Memory Clinic at the National Center for Geriatrics and Gerontology of Japan. PF status was defined based on the definition proposed by Fried and colleagues. CF was defined as simultaneous presence of pre-PF or PF and MCI. WMH volumes were measured using an automatic segmentation application. Multiple liner regression analyses with adjustment for cardiovascular risk factors were performed.

RESULTS

Of all subjects, 77 (63.6%) and 22 (18.2%) CN patients and 132 (62.3%) and 65 (30.7%) MCI patients were categorized into pre-PF and PF, respectively. Multiple liner regression analysis showed that those with CF had higher WMH volumes than those without (β= 0.23). When categorized into six groups according to PF and cognitive status, the PF/CN (β= 0.15), pre-PF/MCI (β= 0.41), and PF/MCI (β= 0.34) groups had higher WMH volumes than the non-PF/CN group.

CONCLUSIONS

This study showed increased WMH volumes in CF and PF, indicating that WMH could be one of the key underlying brain pathologies of CF.

Microstructural Neuroimaging of Frailty in Cognitively Normal Older Adults

Physical frailty is an age-related clinical syndrome that is associated with multiple adverse health outcomes, including cognitive impairment and dementia. Recent studies have shown that frailty is associated with specific volumetric neuroimaging characteristics. Whether brain microstructural characteristics, particularly gray matter, associated with frailty exist and what their spatial distribution is have not been explored. We identified 670 participants of the Baltimore Longitudinal Study of Aging who were aged 60 and older and cognitively normal and who had concurrent data on frailty and regional microstructural neuroimaging markers by diffusion tensor imaging (DTI), including mean diffusivity (MD) of gray matter and fractional anisotropy (FA) of white matter. We identified neuroimaging markers that were associated with frailty status (non-frail, pre-frail, frail) and further examined differences between three groups using multivariate linear regression (non-frail = reference). Models were adjusted for age, sex, race, years of education, body mass index, scanner type, and Apolipoprotein E e4 carrier status. Compared to the non-frail participants, those who were frail had higher MD in the medial frontal cortex, several subcortical regions (putamen, caudate, thalamus), anterior cingulate cortex, and a trend of lower FA in the body of the corpus callosum. Those who were pre-frail also had higher MD in the putamen and a trend of lower FA in the body of the corpus callosum. Our study demonstrates for the first time that the microstructure of both gray and white matter differs by frailty status in cognitively normal older adults. Brain areas were not widespread but mostly localized in frontal and subcortical motor areas and the body of the corpus callosum. Whether changes in brain microstructure precede future frailty development warrants further investigation.

Cross-sectional and prospective associations between cerebral cortical thickness and frailty in older adults

BACKGROUND

Several neurodegenerative markers measured by magnetic resonance imaging (MRI) have shown to be related with frailty. While most studies have focused on surrogates of cerebral vascular damage such as increased white matter lesions, the associations between cortical atrophy and frailty were less often investigated.

OBJECTIVES

To investigate the cross-sectional and prospective associations between cortical thickness and frailty evolution in older adults.

METHODS

We enrolled 484 community-dwelling adults aged ≥70 years, participants from the Multidomain Alzheimer Preventive Trial (MAPT), with data on cerebral cortical thickness and frailty. Cortical thickness was acquired by MRI for whole-brain and regional cortices. Two function-specific regions of interest, i.e., mobility-related regions and Alzheimer's disease (AD) signature, were selected on the basis of previous studies. Frailty status was assessed by the Fried frailty phenotype (i.e., weakness, slowness, involuntary weight loss, fatigue and low physical activity level) at baseline, after 6 months and every year until the end of the 5-year follow-up.

RESULTS

Older adults with higher global cortical thickness were less likely to be pre-frail and frail at baseline (adjusted OR: 0.13, 95% CI: 0.03-0.65, p = 0.013). In addition, higher cortical thickness in mobility-related and AD-signature regions were associated with lower likelihood of being pre-frail and frail. Similar associations were observed for having weakness and slowness. However, neither global nor region-specific cortical thickness showed prospective associations with future frailty onset.

CONCLUSIONS

The global and regional cortical thickness cross-sectionally associated with frailty in older adults, but no prospective associations with incident frailty were found. The longitudinal relationship between cortical thickness and frailty evolution requires further investigation.

Functional Connectivity Disruption in Frail Older Adults Without Global Cognitive Deficits

Frailty is a common representation of cumulative age-related decline that may precede disability in older adults. In our study, we used magnetoencephalography (MEG) to explore the existence of abnormalities in the synchronization patterns of frail individuals without global cognitive impairment. Fifty-four older (≥70 years) and cognitively healthy (Mini-Mental State Examination ≥24) adults, 34 robust (not a single positive Fried criterion) and 20 frail (≥3 positive Fried criteria) underwent a resting-state MEG recording and a T1-weighted magnetic resonance imaging scan. Seed-based functional connectivity (FC) analyses were used to explore group differences in the synchronization of fronto-parietal areas relevant to motor function. Additionally, we performed group comparisons of intra-network FC for key resting-state networks such as the sensorimotor, fronto-parietal, default mode, and attentional (dorsal and ventral) networks. Frail participants exhibited reduced FC between posterior regions of the parietal cortex (bilateral supramarginal gyrus, right superior parietal lobe, and right angular gyrus) and widespread clusters spanning mainly fronto-parietal regions. Frail participants also demonstrated reduced intra-network FC within the fronto-parietal, ventral attentional, and posterior default mode networks. All the FC results concerned the upper beta band, a frequency range classically linked to motor function. Overall, our findings reveal the existence of abnormalities in the synchronization patterns of frail individuals within central structures important for accurate motor control. This study suggests that alterations in brain connectivity might contribute to some motor impairments associated with frailty.

Impact of frailty on short-term outcomes in patients undergoing transsphenoidal pituitary surgery

OBJECTIVE

Frailty, a state of decreased physiological reserve, has been shown to significantly impact outcomes of surgery. The authors sought to examine the impact of frailty on the short-term outcomes of patients undergoing transsphenoidal pituitary surgery.

METHODS

Weighted data from the 2000-2014 National (Nationwide) Inpatient Sample were studied. Patients diagnosed with pituitary tumors or disorders who had undergone transsphenoidal pituitary surgery were identified. Frailty was determined using the Johns Hopkins Adjusted Clinical Groups (ACG) frailty-defining diagnoses indicator. Standard descriptive techniques and matched propensity score analyses were used to explore the odds ratios of postoperative complications, discharge dispositions, and costs.

RESULTS

A total of 115,317 cases were included in the analysis. Frailty was present in 1.48% of cases. The mean age of frail versus non-frail patients was 57.14 ± 16.96 years (mean ± standard deviation) versus 51.91 ± 15.88 years, respectively (p < 0.001). A greater proportion of frail compared to non-frail patients had an age ≥ 65 years (37.08% vs 24.08%, respectively, p < 0.001). Frail patients were more likely to be black or Hispanic (p < 0.001), possess Medicare or Medicaid insurance (p < 0.001), belong to lower-median-income groups (p < 0.001), and have greater comorbidity (p < 0.001). Results of propensity score-matched multivariate analysis revealed that frail patients were more likely to develop fluid and electrolyte disorders (OR 1.61, 95% CI 1.07-2.43, p = 0.02), intracranial vascular complications (OR 2.73, 95% CI 1.01-7.49, p = 0.04), mental status changes (OR 3.60, 95% CI 1.65-7.82, p < 0.001), and medical complications including pulmonary insufficiency (OR 2.01, 95% CI 1.13-4.05, p = 0.02) and acute kidney failure (OR 4.70, 95% CI 1.88-11.74, p = 0.01). The mortality rate was higher among frail patients (1.46% vs 0.37%, p < 0.001). Frail patients also demonstrated a greater likelihood for nonroutine discharges (p < 0.001), higher mean total charges ($109,614.33 [95% CI $92,756.09-$126,472.50] vs $56,370.35 [95% CI $55,595.72-$57,144.98], p < 0.001), and longer hospitalizations (9.27 days [95% CI 7.79-10.75] vs 4.46 days [95% CI 4.39-4.53], p < 0.001).

CONCLUSIONS

Frailty in patients undergoing transsphenoidal pituitary surgery is associated with worse postoperative outcomes and higher costs, indicating that state's potential role in routine preoperative risk stratification.

Prospective Associations Between Diffusion Tensor Imaging Parameters and Frailty in Older Adults

BACKGROUND

Cross-sectional associations have been found between frail individuals and worse white matter (WM) integrity. However, the prospective association between WM integrity and frailty is still unclear. Our objectives were to measure associations between WM integrity using diffusion tensor imaging (DTI) and the 5-year worsening of frailty in community-dwelling older adults.

DESIGN

Secondary analysis of the randomized controlled Multidomain Alzheimer Preventive Trial (MAPT).

SETTING

Thirteen memory centers in France and Monaco between 2008 and 2011.

PARTICIPANTS

Participants (mean age = 74.7 ± 3.9 years) with no dementia at baseline who had functional magnetic resonance imaging performed as part of the MAPT study (n = 227).

MEASUREMENTS

Fractional anisotropy and mean diffusivity (MD), axial diffusivity (AxD), and radial diffusivity (RD) were acquired for 10 different brain regions. Frailty was assessed by the Fried frailty phenotype (score from 0 to 5, higher is worse) at up to seven time points for 5 years. Mixed effect ordinal logistic regression model was used to assess the prospective association between DTI parameters (independent variables) and frailty (dependent variable). All the analyses were adjusted for age, sex, baseline total intracranial volume, and the presence of one of the following cardiovascular risk factors (hypertension, diabetes, and/or hypercholesterolemia).

RESULTS

A statistically significant association was found between the RD, AxD, and MD for different brain regions (anterior limb of internal capsule, external capsule, posterior corona radiata, posterior thalamic radiation, superior corona radiata, superior frontal occipital fasciculus, and superior longitudinal fasciculus) and worsening of frailty over 5 years after adjusting for multiple comparisons.

CONCLUSIONS

This is the first study to show that WM integrity is associated with frailty in older adults. The mechanisms related to these results require further investigation. J Am Geriatr Soc 68:1050-1055, 2020.

White Matter Hyperintensities and the Progression of Frailty—The Tasmanian Study of Cognition and Gait

Background

The contribution of cerebral small vessel disease (cSVD) to the pathogenesis of frailty remains uncertain. We aimed to examine the associations between cSVD with progression of frailty in a population-based study of older people.

Methods

People aged between 60 and 85 years were randomly selected form the electoral roll to participate in the Tasmanian Study of Cognition and Gait. Participants underwent self-reported questionnaires, objective gait, cognitive and sensorimotor testing over three phases ranging between 2005 and 2012. These data were used to calculate a 41-item frailty index (FI) at three time points. Baseline brain magnetic resonance imaging was performed on all participants to measure cSVD. Generalized mixed models were used to examine associations between baseline cSVD and progression of frailty, adjusted for confounders of age, sex, level of education, and total intracranial volume.

Results

At baseline (n = 388) mean age was 72 years (SD = 7.0), 44% were female, and the median FI score was 0.20 (interquartile range [IQR] 0.12, 0.27). In fully adjusted models higher burden of baseline white matter hyperintensity (WMH) was associated with frailty progression over 4.4 years (β = 0.03, 95% CI: 0.01, 0.05; p = .004) independent of other SVD markers. Neither baseline infarcts (p = .23), nor microbleeds at baseline (p = .65) were associated with progression of frailty.

Conclusions

We provide evidence for an association between baseline WMHs and progression of frailty. Our findings add to a growing body of literature suggesting WMH is a marker for frailty.

Frailty Syndromes in Persons With Cerebrovascular Disease: A Systematic Review and Meta-Analysis

Background: Frailty can change the prognosis and treatment approach of chronic diseases. Among others, frailty has been associated with cerebrovascular diseases such as stroke. However, the extent to which the two conditions are related is unclear, and no systematic review of the literature has been conducted. Objectives: To conduct a systematic review and meta-analysis assessing the association of cerebrovascular diseases and frailty, as well as prefrailty, in observational studies. The project was carried out on behalf of the Joint Action ADVANTAGE WP4 group. Methods: The review was performed according to PRISMA guidelines. We searched PubMed, Web of Science, and Embase from 01/01/2002-26/05/2019. Pooled estimates were obtained through random effect models and Mantel-Haenszel weighting. Homogeneity was assessed with the I2 statistic. Publication bias was assessed with Egger's and Begg's tests. Results: Of 1027 studies searched, 18 studies were included (n = 48,009 participants). Stroke was the only cerebrovascular disease studied in relation to frailty syndromes. All studies except one reported an association between stroke and prefrailty or frailty. However, most studies were not of high quality and there was heterogeneity between results. The pooled prevalence of prefrailty and frailty in stroke patients was 49% (95% CI = 42-57) and 22% (95% CI = 16-27), respectively. The prevalence of frailty was 2-fold in persons with stroke compared to those without stroke (pooled odds ratio = 2.32, 95% CI = 2.11-2.55). Only two studies longitudinally examined the association between stroke and frailty, producing conflicting results. Conclusions: Frailty and prefrailty are common in persons with stroke. These results may have clinical implications, as they identify the need to assess frailty in post-stroke survivors and assess how it may affect prognosis. Better quality, longitudinal research that examines the temporal relationship between stroke and frailty are needed, as well as studies on other types of cerebrovascular disease.

Impaired Cerebral Hemodynamics and Frailty in Patients with Cardiovascular Disease

Background

Recent studies suggest that impaired cerebrovascular reactivity (CVR), a marker of cerebral microvascular damage, is associated with a higher risk of stroke, cognitive decline, and mortality. We tested whether abnormal cerebrovascular status is associated with late-life frailty among men with pre-existing cardiovascular disease.

Methods

A subset of 327 men (mean age at baseline 56.7 ± 6.5 years) who previously participated in the Bezafibrate Infarction Prevention (BIP) trial (1990-1997) and then in the BIP Neurocognitive Study underwent a neurovascular evaluation 14.6 ± 1.9 years after baseline (T1) and were evaluated for frailty 19.9 ± 1.0 years after baseline (T2). CVR was measured at T1 using the breath-holding index and carotid large-vessel disease using ultrasound. Frailty status was measured at T2 according to the physical phenotype developed by Fried. Patients were categorized into CVR tertiles with cutoff points at ≤0.57, 0.58-0.94, and ≥0.95 and also as normal or impaired (<0.69) CVR. We assessed the change in the odds of being in the advanced rank of frailty status (normal, prefrail, and frail) using ordered logistic regression.

Results

After adjustment, the estimated OR (95% confidence intervals) for increasing frailty in the lower tertile was 1.94 (1.09-3.46) and in the middle tertile 1.24 (0.70-2.19), compared with the higher CVR tertile. The estimated OR for increasing frailty for patients with impaired vs. normal CVR was 1.76 (1.11-2.80).

Conclusions

These findings provide support that cerebral microvascular dysfunction among patients with pre-existing cardiovascular disease is related to prefrailty and frailty and suggest an added value of assessing the cerebral vascular functional status for identifying patients at-risk of developing frailty.

The association between frailty and MRI features of cerebral small vessel disease

Frailty is a common syndrome in older individuals that is associated with poor cognitive outcome. The underlying brain correlates of frailty are unclear. The aim of this study was to investigate the association between frailty and MRI features of cerebral small vessel disease in a group of non-demented older individuals. We included 170 participants who were classified as frail (n = 30), pre-frail (n = 85) or non-frail (n = 55). The association of frailty and white matter hyperintensity volume and shape features, lacunar infarcts and cerebral perfusion was investigated by regression analyses adjusted for age and sex. Frail and pre-frail participants were older, more often female and showed higher white matter hyperintensity volume (0.69 [95%-CI 0.08 to 1.31], p = 0.03 respectively 0.43 [95%-CI: 0.04 to 0.82], p = 0.03) compared to non-frail participants. Frail participants showed a non-significant trend, and pre-frail participants showed a more complex shape of white matter hyperintensities (concavity index: 0.04 [95%-CI: 0.03 to 0.08], p = 0.03; fractal dimensions: 0.07 [95%-CI: 0.00 to 0.15], p = 0.05) compared to non-frail participants. No between group differences were found in gray matter perfusion or in the presence of lacunar infarcts. In conclusion, increased white matter hyperintensity volume and a more complex white matter hyperintensity shape may be structural brain correlates of the frailty phenotype.

Frailty and Brain-Muscle Correlates in Older People With Type 2 Diabetes: A structural-MRI Explorative Study

OBJECTIVES

Muscle alterations, mainly functional alterations are frequently observed in older people with type 2 diabetes (T2DM). Sarcopenia may be one mechanism of transition to frailty in these people. Thus, we aim to explore the characteristics of muscle and its association with cerebral grey matter volumes within this group.

METHODS

Single center study nested within the international MID-Frail (a randomized clinical trial to evaluate the effectiveness of a multi-modal intervention in older people with T2DM on frailty and quality of life) trial participants underwent both brain and muscle T1 MRI, nutritional and functional assessments. Muscle areas were measured in rectus femoris (RF). Relationships between MRI grey matter volumes and muscle areas or function tests were described using positive and negative regressions.

RESULTS

Twenty-six subjects (7 female, mean age 78.2 y, SD 5.0), 6 frail and 20 pre-frail were explored in this sub-study. Frail subjects had lower Mini Nutritional Assessment (MNA), Short Physical Performance Battery (SPPB), hip flexor strength than pre-frail ones but similar BMI and balance. Total SPPB was positively related with hip flexor strength and maximal RF area. Balance SPPB sub-score was unrelated to strength or RF area. MNA score was correlated with hip flexor strength and to global grey matter but not to SPPB. Hip flexor strength was correlated with grey matter areas involved in motor control. Walking time was negatively and rising chair sub-score was positively associated with grey matter volumes of motor areas.

CONCLUSIONS

Sarcopenia features were more frequent in frail than prefrail subjects and were associated with decrease in grey matter volumes involved in motor control.

Scoping Review of Neuroimaging Studies Investigating Frailty and Frailty Components

Background: Neuroimaging techniques are a cornerstone for diagnosing and investigating cognitive decline and dementia in the elderly. In frailty research, the physical as opposed to the cognitive domain of the aging process, neuroimaging studies are less common. Here we systematically review the use of neuroimaging techniques in frailty research.

Methods: We searched PUBMED for any publication reporting the association between neuroimaging markers and frailty, following Fried's original definition, as well as its determining phenotypes: gait speed, grip strength, fatigue and recent weight loss in the non-diseased population older than 65 years.

Results: The search returned a total of 979 abstracts which were independently screened by 3 reviewers. In total, 17 studies met the inclusion criteria. Of these, 12 studies evaluated gait speed, 2 grip strength, and 3 frailty (2 Fried Frailty, 1 Frailty Index). An association between increased burden of white matter lesions, lower fractional anisotropy, and higher diffusivity has been associated consistently to frailty and worse performance in the different frailty components.

Conclusions: White matter lesions were significantly associated to frailty and frailty components thus highlighting the potential utility of neuroimaging in unraveling the underlying mechanisms of this state. However, considering small sample size and design effects, it is not possible to completely rule out reverse causality between frailty and neuroimaging findings. More studies are needed to clarify this important clinical question.

Modelling physical resilience in ageing mice

Geroprotectors, a class of drugs targeting multiple deficits occurring with age, necessitate the development of new animal models to test their efficacy. The COST Action MouseAGE is a European network whose aim is to reach consensus on the translational path required for geroprotectors, interventions targeting the biology of ageing. In our previous work we identified frailty and loss of resilience as a potential target for geroprotectors. Frailty is the result of an accumulation of deficits, which occurs with age and reduces the ability to respond to adverse events (physical resilience). Modelling frailty and physical resilience in mice is challenging for many reasons. There is no consensus on the precise definition of frailty and resilience in patients or on how best to measure it. This makes it difficult to evaluate available mouse models. In addition, the characterization of those models is poor. Here we review potential models of physical resilience, focusing on those where there is some evidence that the administration of acute stressors requires integrative responses involving multiple tissues and where aged mice showed a delayed recovery or a worse outcome then young mice in response to the stressor. These models include sepsis, trauma, drug- and radiation exposure, kidney and brain ischemia, exposure to noise, heat and cold shock.

The association between brain volume, cortical brain infarcts, and physical frailty

Physical frailty is an age-associated syndrome of decreased reserve leading to vulnerability to physiological stressors and associated with negative outcomes. The underlying structural brain abnormalities of physical frailty are unclear. We investigated the association between brain volume, cortical brain infarcts, and physical frailty. In this multicenter study, 214 nondemented participants were classified as frail (n = 32), prefrail (n = 107), or nonfrail (n = 75) based on the Fried frailty phenotype. The associations between frailty and brain volumes and cortical brain infarcts were investigated by linear or logistic regression analyses. Participants in the frail group showed a lower total brain volume (−19.67 mL [95% confidence interval −37.84 to −1.50]) and lower gray matter volume (−12.19 mL [95% confidence interval −23.84 to −0.54]) compared to nonfrail participants. Frailty was associated with cortical brain infarcts [frail 16% [n = 5], prefrail 11% [n = 12], and nonfrail 3% [n = 2]). Reduced total brain volume and gray matter volume and increased cortical brain infarcts seem therefore to be part of the structural substrate of the physical frailty phenotype.

Association Between Frailty and HIV-Associated Neurodegenerative Disorders Among Older Adults Living with HIV

The population of aging adults living with human immunodeficiency virus (HIV) is growing worldwide and evidence suggests that frailty occurs prematurely among them. In turn, frailty has been associated with cognitive decline. It is unknown, however, if people with both frailty and HIV infection have a higher risk of cognitive impairment compared with nonfrail HIV-infected persons. Therefore, the main objective of this study was to determine the association between the phenotype of frailty and HIV-associated neurocognitive disorders (HAND) among adults aged 50 years or older living with HIV/AIDS. A cross-sectional study was conducted on 206 adults living with HIV receiving care in a university-affiliated tertiary care hospital in Mexico City. Frailty was defined as per the Fried criteria. The presence of HAND was established according to the Antinori criteria: HIV-associated asymptomatic neurocognitive impairment (ANI), HIV-associated mild neurocognitive disorder (MND), or cognitively nonimpaired. Multinomial logistic regression models were used to test the independent association between frailty and HAND adjusting for potential confounders. Mean age of participants was 60.5 ± 6.3 years and 84.9% were male. Prevalence of HAND and frailty phenotype was 66.0% and 2.9%, respectively. The unadjusted analysis showed that both prefrail and frail statuses were associated with MND but not with ANI. However, after adjustment, the association with MND remained significant only among prefrail participants and no longer for frail persons (risk ratio [RR] = 5.7, 95% confidence intervals [CI] 1.09-29.82; p = .039 and RR = 18.3, 95% CI 0.93-362.6; p = .056, respectively). Prefrailty is associated with symptomatic neurocognitive disorders in older adults living with HIV. The spectrum of the frailty phenotype in this already vulnerable population should serve as an indicator of concomitant cognitive decline.

Cognitive Impairment and Overall Survival in Frail Surgical Patients

BACKGROUND

The definition of frailty, as modeled by the Fried criteria, has been limited primarily to the physical domain. The purpose of this study was to assess the additive value of cognitive function with existing frailty criteria to predict poor postoperative outcomes in a large multidisciplinary cohort of patients undergoing major operations.

STUDY DESIGN

A 4-level composite frailty scoring system was created via the combination of the Fried frailty score and the Emory Clock Draw Test to assess preoperative frailty and cognitive impairment, respectively. Overall survival was defined as months from date of operation to date of death or last follow-up.

RESULTS

This study included 330 patients undergoing major operations; mean age was 58 years and a total of 53 patient deaths occurred during 4-year follow-up. Among the robust cohort, 20 of 168 patients died (11.9%), and among those who were both physically frail and cognitively impaired, 11 of 26 patients died (42.3%). Multivariable analysis demonstrated the physically frail and cognitively impaired cohort to have a 3.92 higher risk of death (95% CI 1.66 to 9.26) compared with the cohort of robust patients (p = 0.002). Kaplan-Meier survival curves reveal an overall difference in long-term survival (log-rank p < 0.0001), driven mainly by the high risk of mortality among patients with both physical frailty and cognitive impairment.

CONCLUSIONS

The use of a combined frailty and cognitive assessment score has a more powerful potential to predict adult patients at higher risk of overall survival than either measurement alone. The addition of cognitive assessment to physical frailty measure can lead to improved preoperative decision making and possibly early intervention, as well as more accurate patient counseling.