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

Cognitive frailty: A comprehensive clinical paradigm beyond cognitive decline

Cognitive frailty is an emerging concept in research and clinical practice that incorporates both physical frailty and mild cognitive impairment (MCI) or subjective cognitive decline (SCD). Unlike traditional approaches that separate physical frailty and dementia, cognitive frailty treats these domains as interrelated and coexisting, with significant implications for clinical outcomes and predicting cognitive decline. Despite growing recognition of this interrelationship, a dualistic view of physical and cognitive processes persists. The paradigm of cognitive frailty holds promise as a biomarker- like amyloid plaques or neurofibrillary tangles- but with the advantage of identifying risk at a prefrail stage, before clinical signs of MCI or dementia emerge. This review examines the pathophysiological and clinical dimensions of cognitive frailty and promotes for its integration into routine assessments in memory clinics.

Neuroimaging Findings in Nondemented Frail Individuals: A Systematic Review

BACKGROUND

Frailty is a chronic condition characterised by the progressive decline of multiple physiological functions. There is a critical need to investigate neuroimaging findings in nondemented frail individuals to better understand the underlying mechanisms and implications of frailty on brain health. This paper is aimed at reviewing neuroimaging studies assessing brain changes in nondemented frail individuals to understand the neuropsychological basis of frailty.

METHODS

A systematic review was conducted on studies focusing on neuroimaging modalities in frailty, including MRI, fMRI, DTI and PET. The review was based on PRISMA instructions and a two-step screening process. The studies evaluating neuroimaging findings of nondemented frail individuals, regardless of publication time or participant age, were included. Data were extracted from the included studies, and the quality of the studies as well as risk of bias was assessed.

RESULTS

Out of 1604 studies screened, 22 eligible studies were included. Out of these, 10 studies had good quality, while others had fair quality according to the Newcastle Ottawa scale (NOS). Of these studies, 18 used Fried criteria or a modified version of it to diagnose frailty, while the Edmonton frailty score (EFS), Rockwood and Mitnitski frailty index and frailty index (FI) were implemented by the remaining studies. The MRI findings indicated significant differences in brain structure between nondemented frail and robust individuals, including an increased number and size of white matter hyperintensities, reduced grey matter volume, higher cerebrospinal fluid (CSF) volume and increased number of cerebral microbleeds (CMBs) in frail participants compared to the robust ones. The studies showed no significant difference between at-risk and robust groups regarding total intracranial volume (TIV). The number of CMBs was associated with prefrailty status and its severity. fMRI studies showed decreased intranetwork mean functional connectivity (FC) in nondemented frail individuals. DTI studies showed lower fractional anisotropy (FA), higher axial diffusivity (AD) and higher radial diffusivity (RD) in the nondemented frail group. The PET scan study showed that mean cortical beta-amyloid level was not associated with FI, but the accumulation of beta-amyloid in the anterior and posterior putamen and precuneus region significantly correlated with frailty and its severity.

CONCLUSION

The study reveals significant differences in brain structures between nondemented frail and robust individuals, including increased white matter hyperintensities and reduced grey matter volume. These differences suggest that vascular changes and brain atrophy in nondemented frail individuals may contribute to cognitive impairment and dementia in the future.

Cognitive Frailty and Aging: Clinical Characteristics, Pathophysiological Mechanisms, and Potential Prevention Strategies

Frailty has been conceptualized not only as a physical disease, but also as a multidomain entity that encompasses a multimorbid status, disability, cognitive impairment, psychosocial risk factors, and even geriatric syndromes. In addition to physical ailments and depending on the diagnostic model. Standardized neuropsychological tests can identify cognitive deficiencies along with mild cognitive impairment, a pre-dementia stage characterized by memory and/or other cognitive domain impairments with relatively preserved instrumental activities of daily living. Hence, the possibility of cognitive frailty (CF), a construct that refers to physical frailty in concurrence with non-dementia cognitive decline, is proposed. The estimated prevalence of CF ranges from 10.3 to 42.8%. It is likely that the pathway to overt cognitive impairment, which does not yet involve physical function, begins with the asymptomatic early accumulation of progressive brain damage. Thus, timely detection strategies that target the initial phases of CF are warranted. The pathophysiological components of CF include dysregulation of the hypothalamic-pituitary axis stress response, imbalance in energy metabolism, impaired cardiovascular function, mitochondrial deterioration, and vascular age-related arterial stiffness. Changes that contribute to this disease can also occur at the cellular level, including overexpression of the renin-angiotensin-aldosterone system, activation of proinflammatory pathways, endothelial dysfunction, reduced nitric oxide production, and increased oxidative stress. Non-pharmacological interventions, that range from dietary and nutritional counseling to psychosocial therapy, are currently the main approaches. Both cognitive and physical training programs are considered to be the best researched and most useful multidomain interventions. Clinicians recognize CF as a valid concept that warrants prevention and treatment strategies supported by current research.

Understanding exogenous factors and biological mechanisms for cognitive frailty: A multidisciplinary scoping review

Cognitive frailty (CF) is the conjunction of cognitive impairment without dementia and physical frailty. While predictors of each element are well-researched, mechanisms of their co-occurrence have not been integrated, particularly in terms of relationships between social, psychological, and biological factors. This interdisciplinary scoping review set out to categorise a heterogenous multidisciplinary literature to identify potential pathways and mechanisms of CF, and research gaps. Studies were included if they used the definition of CF OR focused on conjunction of cognitive impairment and frailty (by any measure), AND excluded studies on specific disease populations, interventions, epidemiology or prediction of mortality. Searches used Web of Science, PubMed and Science Direct. Search terms included "cognitive frailty" OR (("cognitive decline" OR "cognitive impairment") AND (frail*)), with terms to elicit mechanisms, predictors, causes, pathways and risk factors. To ensure inclusion of animal and cell models, keywords such as "behavioural" or "cognitive decline" or "senescence", were added. 206 papers were included. Descriptive analysis provided high-level categorisation of determinants from social and environmental through psychological to biological. Patterns distinguishing CF from Alzheimer's disease were identified and social and psychological moderators and mediators of underlying biological and physiological changes and of trajectories of CF development were suggested as foci for further research.

Exploring the relationship between frailty and executive dysfunction: the role of frontal white matter hyperintensities

Introduction

Frailty is a geriatric syndrome frequently associated with executive dysfunction and white matter hyperintensities (WMH). But the relation between executive dysfunction and brain changes is poorly understood in frail subjects. Our hypothesis is that frontal-WMH mediates the association between frailty and executive dysfunction.

Methods

A convenience sample of 113 subjects older than 65 years without dementia was studied with neuropsychological test, a structured clinical interview, physical examination and brain MRI. They were classified as robust or pre-frail and frail using the frailty phenotype score (0-5). The frontal WMH (F-WMH) were manually graduated (0-6) using the "Age-Related White Matter Changes score" from FLAIR sequences at a 3 Tesla brain MRI. A mediation analysis was done for testing whether F-WMH could act as a link factor between frailty phenotype score and executive dysfunction.

Results

The group's mean age was 74 ± 6 years, subjects with higher frailty score had more depressive symptoms and worse performance in executive function tests. A regression analysis that explained 52% of the variability in executive functions, revealed a significant direct effect of frailty score (Standardized βcoeff [95% CI] -0.201, [-0.319, -0.049], and F-WMH (-0.152[-0.269, -0.009]) on executive functions, while the F-WMH showed a small partial mediation effect between frailty and executive functions (-0.0395, [-0.09, -0.004]).

Discussion

Frontal matter hyperintensities had a small mediation effect on the association between frailty and executive dysfunction, suggesting that other neuropathological and neurofunctional changes might also be associated with executive dysfunction in frail subjects.

Institutional Residence Protects Against Cognitive Frailty: A Cross-Sectional Study

Based on the complex aging background, more and more older people have to live in an institution in later life in China. The prevalence of cognitive frailty (CF) is more higher in institutions than in communities. Rarely studies were conducted on the relationship between institutional residence and CF. Hence, this study were performed to determine the relationship between institutional residence (living in a nursing home) and CF in older adults. A total of 1004 older community residents and 111 older nursing home residents over 50 years of age from Hefei, Anhui Province, China were recruited. CF included physical frailty (PF) and mild cognitive impairment (MCI). PF was assessed using the Chinese version of the Fried frailty scale, MCI was assessed using the Montreal Cognitive Assessment, and the common associated factors including sedentary behavior, exercise, intellectual activity, comorbidity, medication, chronic pain, sleep disorders, nutritional status and loneliness were analyzed using regression logistic models. Multivariate regression logistic analysis showed that exercise (P = .019, odds ratio [OR] = 0.494, 95% confidence interval [CI]: 0.274-0.891), intellectual activity (P = .019, OR = 0.595, 95% CI: 0.380-0.932), medication use (P = .003, OR = 2.388, 95% CI: 1.339-4.258), chronic pain (P = .003, OR = 1.580, 95% CI: 1.013-2.465) and loneliness (P = .000, OR = 2.991, 95% CI: 1.728-5.175) were significantly associated with CF in community residents; however, only sedentary behavior (P = .013, OR = 3.851, 95% CI: 1.328-11.170) was significantly associated with CF in nursing home residents. Our findings suggest that nursing homes can effectively address many common risk factors for CF, including lack of exercise and intellectual activity, medication use, chronic pain, and loneliness, better than the community setting. Thus, residing in a nursing home is conducive to the intervention of CF.

Does cognitive frailty predict delayed neurocognitive recovery after noncardiac surgery in frail elderly individuals? Probably not

Introduction

Delayed neurocognitive recovery (DNR) is a common post-surgical complication among the elderly. Cognitive frailty (CF) is also an age-related medical syndrome. However, little is known about the association between CF and DNR. Therefore, this study aimed to study whether CF is associated with DNR in elderly patients undergoing elective noncardiac surgery, as well as to explore the potential risk factors for DNR in frail elderly individuals and construct a prediction model.

Methods

This prospective cohort study administered a battery of cognitive and frailty screening instruments for 146 individuals (≥65 years old) scheduled for elective noncardiac surgery. Screening for CF was performed at least one day before surgery, and tests for the presence of DNR were performed seven days after surgery. The association between CF and DNR was investigated. Moreover, the study subjects were randomly divided into a modeling group (70%) and a validation group (30%). Univariate and multivariate logistic regression was performed to analyze the modeling group data and identify the independent risk factors for DNR. The R software was used to construct DNR's nomogram model, verifying the model.

Results

In total, 138 individuals were eligible. Thirty-three cases were diagnosed with DNR (23.9%). No significant difference in the number of patients with CF was observed between the DNR and non-DNR groups (P > 0.05). Multivariate analysis after adjusting relevant risk factors showed that only the judgment of line orientation (JLOT) test score significantly affected the incidence of DNR. After internal validation of the constructed DNR prediction model, the area under the curve (AUC) of the forecast probability for the modeling population (n = 97) for DNR was 0.801, and the AUC for the validation set (n = 41) was 0.797. The calibration curves of both the modeling and validation groups indicate that the prediction model has good stability.

Conclusion

Cognitive frailty is not an independent risk factor in predicting DNR after noncardiac surgery in frail elderly individuals. The preoperative JLOT score is an independent risk factor for DNR in frail elderly individuals. The prediction model has a good degree of discrimination and calibration, which means that it can individually predict the risk probability of DNR in frail elderly individuals.

Exercise interventions for older people with cognitive frailty-a scoping review

BACKGROUND

As the global population ages, the issue of frailty in older people is gaining international attention. As one of the major subtypes of frailty, cognitive frailty is a heterogeneous clinical manifestation characterised by the co-existence of physical decline and cognitive impairment. The occurrence of cognitive frailty increases the risk of adverse health outcomes in older people, affecting their daily functioning and quality of life. However, cognitive frailty is a reversible state, and many interventions have been explored, with exercise interventions playing an important role in the non-pharmacological management of cognitive frailty. This study describes and summarises current exercise interventions for older people with cognitive frailty (including parameters such as mode, frequency and duration of exercise) and identifies the limitations of existing studies to inform future exercise interventions for older people with cognitive frailty.

METHODS

Using a scoping review approach, Chinese and English literature published in PubMed, Web of Science, Cochrane Library, Embase, China Knowledge Network, Wanfang Database, China Biomedical Literature Database (SinoMed) and Vipshop from April 2013, when the definition of cognitive frailty first appeared, to August 2021 was searched to select studies related to exercise interventions for this group, extract information from the included literature, and summarise and report the findings.

RESULTS

Nine RCT trial studies and one quasi-experiment study were included, for a total of 10 articles. The exercise modalities involved walking, brisk walking, Otago exercise, resistance exercise, balance training, flexibility training and Baduanjin, etc.; the intensity of exercise was based on individualised guidance and graded exercise intensity; the frequency of exercise was mostly 3-4 times/week; the duration of exercise was mostly 30-60 min/time; compared to the control group, the included studies showed statistically significant improvements in cognitive function, frailty status, and depression with the exercise intervention.

CONCLUSION

There is a paucity of evidence on exercise interventions for older people with cognitive frailty. The evidence provided in this study suggests that exercise interventions may be beneficial for older people with cognitive frailty. However, the existing studies suffer from small sample sizes, short intervention periods, inadequate monitoring of the entire exercise process, and non-uniformity in the assessment of exercise effects. More randomized controlled trials should be conducted in the future to explore the most effective, low-cost and simple interventions to meet the needs of the older people with cognitive frailty.

Neuroimaging correlates of persistent fatigue in older adults: A secondary analysis from the Multidomain Alzheimer Preventive Trial (MAPT) trial

OBJECTIVES

Fatigue has been suggested as a marker of biological aging. It seems plausible that this symptom might be associated with changes in brain health. The objective of this study was to examine the associations between persistent fatigue and neuroimaging correlates in a non-disease-specific population of community-dwelling older adults.

METHODS

We performed a cross-sectional analysis using data from The Multidomain Alzheimer Preventive Trial (MAPT). We included 458 subjects. Persistent fatigue was defined as meeting exhaustion criterion of Fried frailty phenotype in two consecutive clinical visits six months apart between study baseline and one year. Brain imaging correlates, assessed by magnetic resonance imaging (MRI), were the outcomes. The associations between persistent fatigue and brain correlates were explored using mixed model linear regressions with random effect at the center level.

RESULTS

The mean age of the participants was 74.8 ± 4 years old, and 63% of the subjects were women. Forty-seven participants (10%) exhibited a persistent fatigue profile. People with persistent fatigue were older compared to subjects without persistent fatigue (76.2 years ± 4.3 vs.74.7 ± 3.9 p = 0.009). Persistent fatigue was associated with higher white matter hyperintensity volume in the fully adjusted analysis. We did not find any cross-sectional association between persistent fatigue and sub-cortical volumes and global and regional cortical thickness.

CONCLUSION

Persistent fatigue was cross-sectionnally associated with higher white matter hyperintensity volume in older adults. Further longitudinal studies, using an assessment tool specifically designed and validated for measuring fatigue, are needed to confirm our findings.

Brain structural alterations and clinical features of cognitive frailty in Japanese community-dwelling older adults: the Arao study (JPSC-AD)

Cognitive frailty (CF) is a clinical condition defined by the presence of both mild cognitive impairment (MCI) and physical frailty (PF). Elderly with CF are at greater risk of dementia than those with MCI or PF alone, but there are few known clinical or neuroimaging features to reliably distinguish CF from PF or MCI. We therefore conducted a population-based cross-sectional study of community elderly combining physical, cognitive, neuropsychiatric, and multisequence magnetic resonance imaging (MRI) evaluations. The MRI evaluation parameters included white matter (WM) lesion volumes, perivascular and deep subcortical WM lesion grades, lacunar infarct prevalence, microbleed number, and regional medial temporal lobe (MTL) volumes. Participants were divided into 4 groups according to the presence or absence of MCI and PF-(1) no MCI, PF (n = 27); (2) no PF, MCI (n = 119); (3) CF (MCI + PF) (n = 21), (4) normal controls (n = 716). Unique features of CF included shorter one-leg standing time; severe depressive symptoms; and MRI signs of significantly more WM lesions, lacunar infarcts, small-vessel disease lesions, microbleeds, and reduced MTL volumes. These unique deficits suggest that interventions for CF prevention and treatment should focus on motor skills, depressive symptoms, and vascular disease risk factor control.

A systematic review and meta-analysis on cognitive frailty in community-dwelling older adults: risk and associated factors

OBJECTIVES

To identify which factors are associated with cognitive frailty (CF), as well as the impact of CF on the incidence of dementia and mortality.

METHODS

A systematic review with meta-analysis was carried out using papers that enrolled a total of 75,379 participants and were published up to January 2020.

RESULTS

Of the 558 identified records, 28 studies met the inclusion criteria and were included in the review. The meta-analysis of cross-sectional studies showed that CF has a significant association of having an older age and a history of falls. In longitudinal studies, the analysis showed a significant increase in risk of mortality and dementia for those with CF.

DISCUSSION

This is the first systematic review and meta-analysis on CF, which addressed a wide variety of factors associated with the theme and which pointed out some as a potential target for prevention or management with different interventions or treatments, showing the clinical importance of its identification in the most vulnerable and susceptible groups.

Cognitive Frailty: An Update

This review article provides an update of the empirical research on cognitive fragility conducted in the last four years. The studies retrieved were classified in four different categories. The first category includes articles relating cognitive frailty to cognitive reserve and which continue to highlight the importance of educational level. The second category includes recent research on cognitive fragility biomarkers, involving neuroimaging, metabolism and, in a novel way, microbiota. The third category includes research on how cognitive frailty is related to motor development and physical functioning, exploring e.g. the use of technology to study motor markers of cognitive frailty. Finally, in the fourth category, research clarifying the difference between reversible frailty and potentially reversible cognitive frailty has led to new interventions aimed at reducing cognitive frailty and preventing negative health outcomes. Interventions based on physical activity and multicomponent interventions are particularly emphasized. In addition, recent research explores the long-term effects of dual interventions in older adults living in nursing homes. In summary, research on cognitive frailty has increased in recent years, and applied aspects have gained importance.

An update on cognitive frailty: Its definition, impact, associated factors and underlying mechanisms, and interventions

Since the concept and operational definition of "cognitive frailty" (simultaneous presence of physical frailty and cognitive impairment without concurrent dementia) were proposed by the International Academy of Nutrition and Aging and the International Association of Gerontology and Geriatrics, cognitive frailty has been widely investigated. This review is intended to address the operational definition of cognitive frailty, its consequences, contributing factors and underlying mechanisms, as well as interventions for cognitive frailty. Although the definitions and assessments of cognitive frailty vary among researchers, older adults with both physical frailty and cognitive impairment are shown to be at higher risk of adverse health outcomes, including death, disability, hospitalization and incident dementia, than those with either condition alone. While the underlying mechanisms of cognitive frailty are still unclear, factors shown to be associated with cognitive frailty include sociodemographic factors, social status, nutritional status, geriatric syndrome, physical and cognitive activities, functional status, comorbidities, medication use, gut-derived metabolites and structural changes in the brain. Accumulating evidence indicates the need for comprehensive geriatric assessment that helps identify the possible causes of cognitive frailty and develop a multimodal individualized intervention to prevent adverse health outcomes for older adults with cognitive frailty. Further studies are required to clarify the mechanisms through which physical frailty and cognitive impairment interact to accelerate adverse health outcomes, particularly cognitive outcomes. In addition, for older adults with cognitive frailty, an effective flow diagram from primary screening through comprehensive assessment to multidimensional intervention needs to be developed for future implementation in both clinical and community settings. Geriatr Gerontol Int 2021; ••: ••-••.

Sleep Quality Mediates the Association Between Cerebral Small Vessel Disease Burden and Frailty: A Community-Based Study

Background: Physical frailty is a common problem among older adults which usually leads to adverse health outcomes. The imaging markers of cerebral small vessel disease (CSVD) are associated with frailty, but the underlying mechanisms remain unclear. The present study aimed to investigate the mediating role of sleep quality in the relationship between CSVD burden and frailty. Methods: We performed a cross-sectional study and enrolled community residents. Frailty and sleep quality were measured using the Fried frailty phenotype and the Pittsburgh Sleep Quality Index (PSQI), respectively. A multivariate linear regression analysis and a Bootstrap analysis were performed to examine the association among the key variables and the mediating role of sleep quality. Results: Of the 726 participants (mean age: 65.5 ± 6.5 years, 59.8% female), the numbers (percentages) of the frail, prefrail, and robust residents were 49 (6.7%), 310 (42.7%), and 367 (50.6%), respectively. After adjusting for covariates, the CSVD burden and PSQI score were significantly associated with the frailty score. In addition, sleep quality played a partial mediating role in the association between CSVD burden and physical frailty. The mediating effect was 21.9%. Conclusion: The present study suggests that sleep quality is a mediator of this association between CSVD and frailty in community-dwelling older adults. Improving sleep quality might be helpful to mitigate the risk of frailty in CSVD patients.

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.

Cognitive Frailty Among Elderly Chinese Patients With Cerebral Small Vessel Disease: A Structural MRI Study

Cognitive frailty (CF) is gaining an increasing amount of attention in geriatric research. CF refers to the co-occurrence of physical frailty and cognitive impairment in people without dementia. Neuroimaging of elderly people has revealed the presence of numerous white matter lesions, which is a typical biomarker of cerebral small vessel disease (SVD) on magnetic resonance images. The aim of the present study was to estimate the prevalence of CF in elderly Chinese patients with SVD. One hundred and thirty elderly patients with SVD were recruited for this cross-sectional observational study. Participants who met three to five of the Fried criteria of the physical frailty (PF) phenotype (shrinking, weakness, slowness, self-reported exhaustion, or low physical activity) were classified as having PF. Then, individuals with PF were defined as having CF if mild cognitive impairment was discovered by the Mini-Mental State Examination. Lastly, a series of cognitive function tests and the dual-task walking paradigm were examined. Based on the CF diagnostic criteria, the frequency of CF was 23.08% among elderly Chinese patients with SVD. Furthermore, CF-positive patients had a more significant SVD burden, based on magnetic resonance imaging findings. Logistic regression analysis, which was adjusted for age, sex, education, and comorbidities, showed that CF was negatively correlated with the dual-task walking speed in elderly people with SVD. Thus, SVD burden might be an indicator of CF phenotype. In elderly patients with SVD, CF was associated with dual task walking performance.

Impact of Cognitive Frailty on Activities of Daily Living, Cognitive Function, and Conversion to Dementia Among Memory Clinic Patients with Mild Cognitive Impairment

BACKGROUND

Very few studies have investigated the impact of cognitive frailty in clinical settings, especially in memory clinic populations.

OBJECTIVE

To examine the impact of cognitive frailty on activities of daily living (ADL), cognitive function, and conversion to dementia among memory clinic patients with mild cognitive impairment (MCI).

METHODS

The subjects of this retrospective study were 248 MCI patients (mean age, 76.3±5.4 years; females, 60.9%). All subjects completed a comprehensive geriatric assessment at baseline and at least one assessment during 3-year follow-up. Frailty was defined by generating a frailty index (FI), and MCI patients with frailty (FI≥0.25) were considered to represent cognitive frailty. As primary outcomes, the Barthel Index, Mini-Mental State Examination, and incident dementia were evaluated during follow-up. At baseline, patients were assessed for apolipoprotein E (APOE) phenotype. A linear mixed model, as well as a Cox proportional hazards regression model with adjustment for confounding variables, was performed.

RESULTS

Of these patients, 75 (30.2%) were classified as cognitive frail. APOEɛ4 carriers accounted for 26.7% of those with cognitive frailty and 44.5% of those without (p = 0.008). Cognitive frail patients showed a faster ADL decline (estimate, -1.04; standard error, 0.38; p = 0.007) than patients without cognitive frailty. Cognitive frailty was not associated with cognitive decline and incident dementia.

CONCLUSION

Our findings demonstrated cognitive frailty increases the risk of dependence but not cognitive outcomes. Cognitive frailty may have heterogeneous conditions, including APOEɛ4-related pathologies, which may affect the cognitive trajectories of patients with MCI.

Frailty Is Associated With Postoperative Delirium But Not With Postoperative Cognitive Decline in Older Noncardiac Surgery Patients

BACKGROUND

Postoperative cognitive dysfunction (POCD) and delirium are the most common perioperative cognitive complications in older adults undergoing surgery. A recent study of cardiac surgery patients suggests that physical frailty is a risk factor for both complications. We sought to examine the relationship between preoperative frailty and postoperative delirium and preoperative frailty and POCD after major noncardiac surgery.

METHODS

We performed a prospective cohort study of patients >65 years old having major elective noncardiac surgery with general anesthesia. Exclusion criteria were preexisting dementia, inability to consent, cardiac, intracranial, or emergency surgery. Preoperative frailty was determined using the FRAIL scale, a simple questionnaire that categorizes patients as robust, prefrail, or frail. Delirium was assessed with the Confusion Assessment Method for the intensive care unit (CAM-ICU) twice daily, starting in the recovery room until hospital discharge. All patients were assessed with neuropsychological tests (California Verbal Learning Test II, Trail Making Test, subtests from the Wechsler Adult Intelligence Scale, Logical Memory Story A, Immediate and Delayed Recall, Animal and Vegetable verbal fluency, Boston Naming Test, and the Mini-Mental Status Examination) before surgery and at 3 months afterward.

RESULTS

A total of 178 patients met inclusion criteria; 167 underwent major surgery and 150 were available for follow-up 3 months after surgery. The median age was 70 years old. Thirty-one patients (18.6%) tested as frail, and 72 (43.1%) prefrail before surgery. After adjustment for baseline cognitive score, age, education, surgery duration, American Society of Anesthesiologists (ASA) physical status, type of surgery, and sex, patients who tested frail or prefrail had an estimated 2.7 times the odds of delirium (97.5% confidence interval, 1.0-7.3) when compared to patients who were robust. There was no significant difference between the proportion of POCD between patients who tested as frail, prefrail, or robust.

CONCLUSIONS

After adjustment for baseline cognition, testing as frail or prefrail with the FRAIL scale is associated with increased odds of postoperative delirium, but not POCD after noncardiac surgery.