Using Photovoice to Explore the Lived Environment and Experience of Older Adults with Frailty on their Kidney Transplant Journey

Key Points

Background

Older adults with frailty and kidney failure face higher waitlist mortality and are more likely to be listed as inactive on the kidney transplant (KT) waitlist. Photovoice is a qualitative participatory research method where participants use photographs to represent their environment, needs, and experiences. It offers unique insight into the lived environment and experience of patients and may offer direction in how to improve functional independence, symptom burden, and KT outcomes in adults with frailty.

Methods

This photovoice study was embedded within a larger intervention adaptation project. Participants with prefrailty or frailty awaiting a KT or recently post-transplant took photographs with Polaroid cameras and wrote short descriptions for 11 prompts. Each participant completed a semistructured interview wherein their photographs were discussed. The team coded and discussed photographs and interviews to determine overarching themes and implications. Focus groups were used to triangulate visual data findings.

Results

Sixteen participants completed both the photovoice and the interview. Participants were a mean age of 60.5 years, 31.2% female, 43.4% self-identifying as Black, and 69% were frail. Outcomes were categorized into seven themes: functional space, home safety, medication management, adaptive coping, life-changing nature of dialysis, support, and communication. Visual data clarified and sometimes changed the interpretations of the text alone. Especially within the themes of home safety and functional space, safety hazards not previously recognized in the literature, like dialysis fluid storage, were identified.

Conclusions

Photovoice contextualizes the living conditions and experiences of adults with frailty on the KT journey and could be a useful tool in geriatric nephrology and transplant. Addressing issues of home storage, organization, and accessibility should be explored as potential intervention targets. Incorporating participant values and goals into care decisions and interventional design should be further explored.

Soluble TNFR1 has greater reproducibility than IL-6 for the assessment of chronic inflammation in older adults: the case for a new inflammatory marker in aging

Chronic inflammatory pathway activation, commonly referred to as "Inflammaging" or chronic inflammation (CI), is associated with frailty, cognitive and functional decline, and other causes of health span decline in older adults. We investigated the variability of candidate serum measures of CI among community-dwelling older adults selected for mild low-grade inflammation. We focused on serum cytokines known to be highly predictive of adverse health outcomes in older adults (sTNFR1, IL-6) during a short-term (weeks) and medium-term (months) follow-up, as well as immune markers that are less studied in aging but reflect other potentially relevant domains such as adaptive immune activation (sCD25), innate immune activation (sCD14 and sCD163), and the inflammation-metabolism interface (adiponectin/Acrp30) during short-term (weeks) follow up. We found that sTNFR1 was more reproducible than IL-6 over a period of weeks and months short-term and medium-term. The intra-class correlation coefficient (ICC) for sTNFR1 was 0.95 on repeated measures over 6 weeks, and 0.79 on repeated measures with mean interval of 14 weeks, while the ICC for IL-6 was 0.52 over corresponding short-term and 0.67 over corresponding medium-term follow-up. This suggests that sTNFR1 is a more reliable marker of CI than IL-6. This study provides new insights into the reproducibility of serum markers of CI in older adults. The findings suggest that sTNFR1 may be a better marker of CI than IL-6 in this population. Further studies are needed to confirm these findings and to investigate the clinical utility of sTNFR1 in older adults.

Unlocking the protective potential of the angiotensin type 2 receptor (AT2R) in acute lung injury and age-related pulmonary dysfunction

Despite its known importance in the cardiovascular system, the specific role and impact of the angiotensin type 2 receptor (AT2R) in lung physiology and pathophysiology remain largely elusive. In this study, we highlight the distinct and specialized lung-specific roles of AT2R, primarily localized to an alveolar fibroblast subpopulation, in contrast to the angiotensin type 1 receptor (AT1R), which is almost exclusively expressed in lung pericytes. Evidence from our research demonstrates that the disruption of AT2R (AT2R-/y), is associated with a surge in oxidative stress and impaired lung permeability, which were further intensified by Hyperoxic Acute Lung Injury (HALI). With aging, AT2R-/y mice show an increase in oxidative stress, premature enlargement of airspaces, as well as increased mortality when exposed to hyperoxia as compared to age-matched WT mice. Our investigation into Losartan, an AT1R blocker, suggests that its primary HALI lung-protective effects are channeled through AT2R, as its protective benefits are absent in AT2R-/y mice. Importantly, a non-peptide AT2R agonist, Compound 21 (C21), successfully reverses lung oxidative stress and TGFβ activation in wild-type (WT) mice exposed to HALI. These findings suggest a possible paradigm shift in the therapeutic approach for lung injury and age-associated pulmonary dysfunction, from targeting AT1R with angiotensin receptor blockers (ARBs) towards boosting the protective function of AT2R.

Late-life plasma proteins associated with prevalent and incident frailty: A proteomic analysis

Proteomic approaches have unique advantages in the identification of biological pathways that influence physical frailty, a multifactorial geriatric syndrome predictive of adverse health outcomes in older adults. To date, proteomic studies of frailty are scarce, and few evaluated prefrailty as a separate state or examined predictors of incident frailty. Using plasma proteins measured by 4955 SOMAmers in the Atherosclerosis Risk in Community study, we identified 134 and 179 proteins cross-sectionally associated with prefrailty and frailty, respectively, after Bonferroni correction (p < 1 × 10-5 ) among 3838 older adults aged ≥65 years, adjusting for demographic and physiologic factors and chronic diseases. Among them, 23 (17%) and 82 (46%) were replicated in the Cardiovascular Health Study using the same models (FDR p < 0.05). Notably, higher odds of prefrailty and frailty were observed with higher levels of growth differentiation factor 15 (GDF15; pprefrailty  = 1 × 10-15 , pfrailty  = 2 × 10-19 ), transgelin (TAGLN; pprefrailty  = 2 × 10-12 , pfrailty  = 6 × 10-22 ), and insulin-like growth factor-binding protein 2 (IGFBP2; pprefrailty  = 5 × 10-15 , pfrailty  = 1 × 10-15 ) and with a lower level of growth hormone receptor (GHR, pprefrailty  = 3 × 10-16 , pfrailty  = 2 × 10-18 ). Longitudinally, we identified 4 proteins associated with incident frailty (p < 1 × 10-5 ). Higher levels of triggering receptor expressed on myeloid cells 1 (TREM1), TAGLN, and heart and adipocyte fatty-acid binding proteins predicted incident frailty. Differentially regulated proteins were enriched in pathways and upstream regulators related to lipid metabolism, angiogenesis, inflammation, and cell senescence. Our findings provide a set of plasma proteins and biological mechanisms that were dysregulated in both the prodromal and the clinical stage of frailty, offering new insights into frailty etiology and targets for intervention.

Serum and plasma protein biomarkers associated with frailty in patients with cirrhosis

Frailty, a clinical phenotype of decreased physiological reserve, is a strong determinant of adverse health outcomes in patients with cirrhosis. The only cirrhosis-specific frailty metric is the Liver Frailty Index (LFI), which must be administered in person and may not be feasible for every clinical scenario. We sought to discover candidate serum/plasma protein biomarkers that could differentiate frail from robust patients with cirrhosis. A total of 140 adults with cirrhosis awaiting liver transplantation in the ambulatory setting with LFI assessments and available serum/plasma samples were included. We selected 70 pairs of patients on opposite ends of the frailty spectrum (LFI>4.4 for frail and LFI<3.2 for robust) who were matched by age, sex, etiology, HCC, and Model for End-Stage Liver Disease-Sodium. Twenty-five biomarkers with biologically plausible associations with frailty were analyzed using ELISA by a single laboratory. Conditional logistic regression was used to examine their association with frailty. Of the 25 biomarkers analyzed, we identified 7 proteins that were differentially expressed between frail and robust patients. We observed differences in 6 of the 7 proteins in the expected direction: (a) higher median values in frail versus robust with growth differentiation factor-15 (3682 vs. 2249 pg/mL), IL-6 (17.4 vs. 6.4 pg/mL), TNF-alpha receptor 1 (2062 vs. 1627 pg/mL), leucine-rich alpha-2 glycoprotein (44.0 vs. 38.6 μg/mL), and myostatin (4066 vs. 6006 ng/mL) and (b) lower median values in frail versus robust with alpha-2-Heremans-Schmid glycoprotein (0.11 vs. 0.13 mg/mL) and free total testosterone (1.2 vs. 2.4 ng/mL). These biomarkers represent inflammatory, musculoskeletal, and endocrine/metabolic systems, reflecting the multiple physiological derangements observed in frailty. These data lay the foundation for confirmatory work and development of a laboratory frailty index for patients with cirrhosis to improve diagnosis and prognostication.

Decoding Angiotensin Receptors: TOMAHAQ-Based Detection and Quantification of Angiotensin Type-1 and Type-2 Receptors

Background The renin-angiotensin system plays a crucial role in human physiology, and its main hormone, angiotensin, activates 2 G-protein-coupled receptors, the angiotensin type-1 and type-2 receptors, in almost every organ. However, controversy exists about the location, distribution, and expression levels of these receptors. Concerns have been raised over the low sensitivity, low specificity, and large variability between lots of commercially available antibodies for angiotensin type-1 and type-2 receptors, which makes it difficult to reconciliate results of different studies. Here, we describe the first non-antibody-based sensitive and specific targeted quantitative mass spectrometry assay for angiotensin receptors. Methods and Results Using a technique that allows targeted analysis of multiple peptides across multiple samples in a single mass spectrometry analysis, known as TOMAHAQ (triggered by offset, multiplexed, accurate mass, high resolution, and absolute quantification), we have identified and validated specific human tryptic peptides that permit identification and quantification of angiotensin type-1 and type-2 receptors in biological samples. Several peptide sequences are conserved in rodents, making these mass spectrometry assays amenable to both preclinical and clinical studies. We have used this method to quantify angiotensin type-1 and type-2 receptors in postmortem frontal cortex samples of older adults (n=28) with Alzheimer dementia. We correlated levels of angiotensin receptors to biomarkers classically linked to renin-angiotensin system activation, including oxidative stress, inflammation, amyloid-β load, and paired helical filament-tau tangle burden. Conclusions These robust high-throughput assays will not only catalyze novel mechanistic studies in the angiotensin research field but may also help to identify patients with an unbalanced angiotensin receptor distribution who would benefit from angiotensin receptor blocker treatment.

A Study of Physical Resilience and Aging (SPRING): Conceptual framework, rationale, and study design

Understanding the physiological basis of physical resilience to clinical stressors is crucial for the well-being of older adults. This article presents a novel framework to discover the biological underpinnings of physical resilience in older adults as part of the "Characterizing Resiliencies to Physical Stressors in Older Adults: A Dynamical Physiological Systems Approach" study, also known as The Study of Physical Resilience and Aging (SPRING). Physical resilience, defined as the capacity of a person to withstand clinical stressors and quickly recover or improve upon a baseline functional level, is examined in adults aged 55 years and older by studying the dynamics of stress response systems. The hypothesis is that well-regulated stress response systems promote physical resilience. The study employs dynamic stimulation tests to assess energy metabolism, the hypothalamic-pituitary-adrenal axis, the autonomic nervous system, and the innate immune system. Baseline characteristics influencing resilience outcomes are identified through deep phenotyping of physical and cognitive function, as well as of biological, environmental, and psychosocial characteristics. SPRING aims to study participants undergoing knee replacement surgery (n = 100), bone and marrow transplantation (n = 100), or anticipating dialysis initiation (n = 60). Phenotypic and functional measures are collected pre-stressor and at multiple times after stressor for up to 12 months to examine resilience trajectories. By improving our understanding of physical resilience in older adults, SPRING has the potential to enhance resilient outcomes to major clinical stressors. The article provides an overview of the study's background, rationale, design, pilot phase, implementation, and implications for improving the health and well-being of older adults.

Substitution of self-reported measures for objectively assessed grip strength and slow walk in the Physical Frailty Phenotype: ramifications for validity

BACKGROUND

Frailty assessment promises to identify older adults at risk for adverse consequences following stressors and target interventions to improve health outcomes. The Physical Frailty Phenotype (PFP) is a widely-studied, well validated assessment but incorporates performance-based slow walk and grip strength criteria that challenge its use in some clinical settings. Variants replacing performance-based elements with self-reported proxies have been proposed. Our study evaluated whether commonly available disability self-reports could be substituted for the performance-based criteria in the PFP while still identifying as "frail" the same subpopulations of individuals.

METHODS

Parallel analyses were conducted in 3393 female and 2495 male Cardiovascular Health Study, Round 2 participants assessed in 1989-90. Candidate self-reported proxies for the phenotype's "slowness" and "weakness" criteria were evaluated for comparable prevalence and agreement by mode of measurement. For best-performing candidates: Frailty status (3 + positive criteria out of 5) was compared for prevalence and agreement between the PFP and mostly self-reported versions. Personal characteristics were compared between those adjudicated as frail by (a) only a self-reported version; (b) only the PFP; (c) both, using bivariable analyses and multinomial logistic regression.

RESULTS

Self-reported difficulty walking ½ mile was selected as a proxy for the phenotype's slowness criterion. Two self-reported weakness proxies were examined: difficulty transferring from a bed or chair or gripping with hands, and difficulty as just defined or in lifting a 10-pound bag. Prevalences matched to within 4% between self-reported and performance-based criteria in the whole sample, but in all cases the self-reported prevalence for women exceeded that for men by 11% or more. Cross-modal agreement was moderate, with by-criterion and frailty-wide Kappa statistics of 0.55-0.60 in all cases. Frail subgroups (a), (b), (c) were independently discriminated (p < 0.05) by race, BMI, and depression in women; by age in men; and by self-reported health for both.

CONCLUSIONS

Commonly used self-reported disability items cannot be assumed to stand in for performance-based criteria in the PFP. We found subpopulations identified as frail by resultant phenotypes versus the original phenotype to systematically differ. Work to develop self-reported proxies that more closely replicate their objective phenotypic counterparts than standard disability self-reports is needed.

Deletion of quinolinate phosphoribosyltransferase gene accelerates frailty phenotypes and neuromuscular decline with aging in a sex-specific pattern

Decline in neuromuscular function with aging is known to be a major determinant of disability and all-cause mortality in late life. Despite the importance of the problem, the neurobiology of age-associated muscle weakness is poorly understood. In a previous report, we performed untargeted metabolomics on frail older adults and discovered prominent alteration in the kynurenine pathway, the major route of dietary tryptophan degradation that produces neurotoxic intermediate metabolites. We also showed that neurotoxic kynurenine pathway metabolites are correlated with increased frailty score. For the present study, we sought to further examine the neurobiology of these neurotoxic intermediates by utilizing a mouse model that has a deletion of the quinolinate phosphoribosyltransferase (QPRT) gene, a rate-limiting step of the kynurenine pathway. QPRT-/- mice have elevated neurotoxic quinolinic acid level in the nervous system throughout their lifespan. We found that QPRT-/- mice have accelerated declines in neuromuscular function in an age- and sex-specific manner compared to control strains. In addition, the QPRT-/- mice show premature signs of frailty and body composition changes that are typical for metabolic syndrome. Our findings suggest that the kynurenine pathway may play an important role in frailty and age-associated muscle weakness.

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.

Patterns of Daily Physical Movement, Chronic Inflammation, and Frailty Incidence

INTRODUCTION

Low physical activity is a criterion of phenotypic frailty defined as an increased state of vulnerability to adverse health outcomes. Whether disengagement from daily all-purpose physical activity is prospectively associated with frailty and possibly modified by chronic inflammation-a pathway often underlying frailty-remains unexplored.

METHODS

Using the Study to Understand Fall Reduction and Vitamin D in You data from 477 robust/prefrail adults (mean age = 76 ± 5 yr; 42% women), we examined whether accelerometer patterns (activity counts per day, active minutes per day, and activity fragmentation [broken accumulation]) were associated with incident frailty using Cox proportional hazard regression. Baseline interactions between each accelerometer metric and markers of inflammation that include interleukin-6, C-reactive protein, and tumor necrosis factor-alpha receptor 1 were also examined.

RESULTS

Over an average of 1.3 yr, 42 participants (9%) developed frailty. In Cox regression models adjusted for demographics, medical conditions, and device wear days, every 30 min·d -1 higher baseline active time, 100,000 more activity counts per day, and 1% lower activity fragmentation was associated with a 16% ( P = 0.003), 13% ( P = 0.001), and 8% ( P < 0.001) lower risk of frailty, respectively. No interactions between accelerometer metrics and baseline interleukin-6, C-reactive protein, or tumor necrosis factor-alpha receptor 1 were detected (interaction P > 0.06 for all).

CONCLUSIONS

Among older adults who are either robust or prefrail, constricted patterns of daily physical activity (i.e., lower total activity minutes and counts, and higher activity fragmentation) were prospectively associated with higher risk of frailty but not modified by frailty-related chronic inflammation. Additional studies, particularly trials, are needed to understand if this association is causal.

Metabolomics-Based Identification of Metabolic Dysfunction in Frailty

Dysregulation of energy producing metabolic pathways has been observed in older adults with frailty. In this study, we used liquid chromatography-mass spectrometry technology to identify aging- and frailty-related differences in metabolites involved in glycolysis, the tricarboxylic (TCA) cycle, and other energy metabolism-related pathways in the serum of a cohort of community-dwelling adults aged 20-97 (n = 146). We also examined the relationship between serum levels of metabolites and functional measures, physical frailty, and risk status for adverse health outcomes. We observed elevated levels of TCA cycle and glycolytic intermediates in frail subjects; however, the differences in the levels of ATP and other energy metabolites between young, nonfrail, and frail adults were not significant. Instead, we found that serum levels of neurotransmitters N-acetyl-aspartyl-glutamate, glutamate, and γ-aminobutyric acid were significantly elevated in older adults with frailty. These elevations of glycolytic and TCA cycle intermediates, and neurotransmitters may be part of the biological signature of frailty.

METABOLIC SYNDROME, GLUCOSE INTOLERANCE, AND PHYSICAL RESILIENCE

When confronted with a major physical stressor, some older adults are able to recover to baseline with minimal changes, while others undergo irreversible declines. The ability to adapt and recover well from physical stress is called physical resilience and may be impeded by altered glucose-insulin dynamics. Among 55 participants in the pilot phase of the Study of Physical Resilience IN Geriatrics(SPRING), we examined associations between metabolic syndrome and/or diabetes status to physical resiliency recovery parameters after the clinical stressors total knee replacement and bone marrow transplant. These parameters included health outcomes, functional recovery, and pain in the weeks after the intervention. Additionally, we hypothesized that less resilient individuals would have abnormal glucose and insulin responses to a 75-gram oral glucose tolerance test at 0, 30, 60, 120 minutes and tested this in a subset (n=40) without known diabetes. Exploratory analyses of this pilot study will be presented during this session.

ATIP LEVELS ARE ASSOCIATED WITH LESS AMYLOID-Β BURDEN IN POSTMORTEM BRAINS OF OLDER ADULTS WITH ALZHEIMER’S DEMENTIA

Angiotensin system, aging, and Alzheimer's disease are tightly linked. Of the brain angiotensin receptors, the subtype 2 receptor (AT2R) is relatively less studied. Canonically, the AT2R functions through nitric oxide release, and its activation has been linked to vasodilatation and neurite outgrowth as well as anti-inflammation. How AT2R signals is not known, however, an AT2R-binding protein (ATIP) has been recently described. Controversies exist on the link between ATIP and AT2R functions. Here, we describe the development of the first non-antibody based ultra-sensitive and specific quantitative mass spectrometry assay for ATIP. Using a technique that permits targeted analysis of multiple peptides across multiple samples in a single mass spectrometry run, known as TOMAHAQ, we have identified specific human tryptic peptides that permit quantification of ATIP abundance. We have used this method to quantify ATIP in postmortem frontal cortex samples of older adults (n= 60) with Alzheimer’s dementia (AD). We correlated levels of ATIP to brain RAS receptors, and biomarkers of AD pathogenesis including oxidative stress, inflammation, mitochondrial dysfunction as well as amyloid-β, and tau burden. Our results show that ATIP expression (ANLKNPQIMYLEQELESLK sequence of ATIP) is positively correlated with neuronal nitric oxide synthase (nNOS) (p = 0.009, r = 0.337). Furthermore, expression of ATIP is negatively correlated with amyloid-β load in several brain regions including hippocampus (p= 0.014, r= -0.317), entorhinal cortex (p= 0.010, r= -0.331), frontal cortex (p= 0.023, r= -0.294), and overall (p= 0.004, r= -0.365). These results highlight a potential protective role for ATIP in Alzheimer’s disease.

Losartan Mitigates Oxidative Stress in the Brains of Aged and Inflamed IL-10-/- Mice

Chronic inflammation, oxidative stress, and dysregulation of the renin-angiotensin system are closely linked, and their crosstalk commonly contributes to age-related physical and cognitive decline. The primary dementia-protective benefits of Angiotensin II type 1 receptor (AT1R) blockers are believed to arise from systemic effects on blood pressure. However, there is an independently regulated brain-specific renin-angiotensin system. Here, we examined the impact of 4 weeks of oral Losartan treatment on the brains of aged (100 weeks old) IL-10-/- mice, an animal model of chronic inflammation and frailty. Our data show that aged IL-10-/- mice have higher AT1R and Nitrotyrosine (oxidative stress marker) levels in their frontal cortex tissue but not in cerebellar or hippocampal tissue compared to age- and sex-matched wild type mice. Losartan treatment for 4 weeks is associated with lower AT1R protein level, Nitrotyrosine, and Tau protein in the frontal cortex of aged IL-10-/- mice. Our results highlight the impact of Losartan, an AT1R blocker commonly prescribed for treating high blood pressure, on the brain-specific angiotensin system and AT1R-linked downstream effects such as brain oxidative stress damage and Tau burden in a frailty mouse model.

Agreement between standard and self-reported assessments of physical frailty syndrome and its components in a registry of community-dwelling older adults

BACKGROUND

The ability to identify frail older adults using a self-reported version of the physical frailty phenotype (PFP) that has been validated with the standard PFP could facilitate physical frailty detection in clinical settings.

METHODS

We collected data from volunteers (N = 182), ages 65 years and older, in an aging research registry in Baltimore, Maryland. Measurements included: standard PFP (walking speed, grip strength, weight loss, activity, exhaustion); and self-reported questions about walking and handgrip strength. We compared objectively-measured gait speed and grip strength to self-reported questions using Cohen's Kappa and diagnostic accuracy tests. We used these measures to compare the standard PFP with self-reported versions of the PFP, focusing on a dichotomized identification of frail versus pre- or non-frail participants.

RESULTS

Self-reported slowness had fair-to-moderate agreement (Kappa(k) = 0.34-0.56) with measured slowness; self-reported and objective weakness had slight-to-borderline-fair agreement (k = 0.10-0.21). Combining three self-reported slowness questions had highest sensitivity (81%) and negative predictive value (NPV; 91%). For weakness, three questions combined had highest sensitivity (72%), while all combinations had comparable NPV. Follow-up questions on level of difficulty led to minimal changes in agreement and decreased sensitivity. Substituting subjective for objective measures in our PFP model dichotomized by frail versus non/pre-frail, we found substantial (k = 0.76-0.78) agreement between standard and self-reported PFPs. We found highest sensitivity (86.4%) and NPV (98.7%) when comparing the dichotomized standard PFP to a self-reported version combining all slowness and weakness questions. Substitutions in a three-level model (frail, vs pre-frail, vs. non-frail) resulted in fair-to-moderate agreement (k = 0.33-0.50) with the standard PFP.

CONCLUSIONS

Our results show potential utility as well as challenges of using certain self-reported questions in a modified frailty phenotype. A self-reported PFP with high agreement to the standard phenotype could be a valuable frailty screening assessment in clinical settings.

The Design and Rationale of a Phase 2b, Randomized, Double-Blinded, and Placebo-Controlled Trial to Evaluate the Safety and Efficacy of Lomecel-B in Older Adults with Frailty

BACKGROUND

Frailty in older adults is a rapidly growing unmet medical need. It is an aging-related syndrome characterized by physical decline leading to higher risk of adverse health outcomes.

OBJECTIVES

To evaluate the efficacy of Lomecel-B, an allogeneic medicinal signaling cell (MSC) formulation, in older adults with frailty.

DESIGN

This multicenter, randomized, parallel-arm, double-blinded, and placebo-controlled phase 2b trial is designed to evaluate dose-range effects of Lomecel-B for frailty on physical functioning, patient-reported outcomes (PROs), frailty status, and biomarkers.

SETTING

Eight enrolling clinical research centers, including the Miami Veterans Affairs Medical Center.

PARTICIPANTS

Target enrollment is 150 subjects aged 70-85 years of any race, ethnicity, or gender. Enrollment criteria include a Clinical Frailty Score of 5 ("mild") or 6 ("moderate"), a 6MWT of 200-400 m, and serum tumor necrosis factor-alpha (TNF-α) ≥2.5 pg/mL.

INTERVENTION

A single intravenous infusion of Lomecel-B (25, 50, 100, or 200 million cells) or placebo (N=30/arm). Patients are followed for 365 days for safety, and the efficacy assessments performed at 90, 180, and 270 days.

MEASUREMENTS

The primary endpoint is change in 6MWT in the Lomecel-B-treated arms versus placebo at 180 days post-infusion. Secondary and exploratory endpoints include change in: 6MWT and other physical function measures at all time points; PROs; frailty status; cognitive status; and an inflammatory biomarkers panel. A pre-specified sub-study examines vascular/endothelial biomarkers. Safety is evaluated throughout the trial.

RESULTS

The trial is conducted under a Food and Drug Administration Investigational New Drug (IND), with Institutional Review Board approval, and monitoring by an NIH-appointed independent Data Safety Monitoring Board.

CONCLUSION

This clinical trial investigates the use of a regenerative medicine strategy for frailty in older adults. The results will further the understanding of the potential for Lomecel-B in the geriatric condition of frailty.

Unexplained anemia of aging: Etiology, health consequences, and diagnostic criteria

BACKGROUND

Up to 15% of people aged 60 and over are anemic, and the prevalence of anemia increases with age. In older men and women, anemia is associated with increases in the risk of death and all-cause hospitalization, poor functional capacity, quality of life, and depression.

METHODS AND RESULTS

We reviewed the literature describing anemia in aging populations, focusing on the specific diagnostic criteria of anemia and potential causes in older men and women. Even after extensive etiologic workup that involves careful medical history, physical examination, laboratory measurements, and additional studies such as bone marrow biopsy, anemia of aging is unexplained in up to 40% of older patients with anemia. As a result, treatment options remain limited.

CONCLUSIONS

The prevalence of unexplained anemia of aging (UAA; also called unexplained anemia of the elderly, UAE), its deleterious impacts on health, physical function, and quality of life, and the lack of effective treatment or therapy guidelines represent a compelling unmet clinical need. In this review and consensus document, we discuss the scope of the problem, possible causes of UAA, diagnostic criteria, and potential treatment options. Because even mild anemia is strongly linked to poor clinical outcomes, it should receive clinical attention rather than simply being considered a normal part of aging.

Angiotensin Receptor Blockers Upregulate Angiotensin Type 4 Receptor in Brains of Cognitively Intact Individuals

The primary dementia-protective benefits of Angiotensin receptor type 1 (AT1R) blockers (ARBs) are believed to arise from systemic effects on blood pressure. However, there is a brain-specific renin-angiotensin system (b-RAS) that acts mainly through three receptor subtypes: AT1R, AT2R, and AT4R. AT1R promotes inflammation and oxidative stress (OS). AT2R increases nitric oxide. AT4R is essential for dopamine release and mediates memory consolidation. Here, we aimed to investigate the effects of ARBs on b-RAS, OS, inflammation, PHF-tau, and beta-amyloid load. Postmortem frontal-cortex brains of age- and sex-matched cognitively intact (CI) individuals using (n=30) and not using ARBs (n=30) and Alzheimer's disease (AD) patients using (n=30) and not using ARBs (n=30) were studied. Protein levels of receptors were measured by Western blot. Protein carbonyl (PC) and cytokine levels were measured by ELISA. Tangle and amyloid-β scores were used as outcomes. In CI individuals, our data shows that ARB treatment was associated with higher protein levels of AT4R (median(range) 0.69(1.92) vs 0.17(1.18) CI+ARBs vs CI, p=0.02), lower level of OS marker PC (10.60(8.32) vs 11.26(7.44), CI+ARBs vs CI, p=0.03) and lower hippocampal and overall amyloid scores (0(5.45) vs 1.15(4.21) p=0.03, 0.79(12.75) vs 3.41(13.36) p=0.04, CI+ARBs vs CI, respectively). In AD group, ARB treatment was associated with lower AT1R protein levels (0.47(1.15) vs 0.59(1.99), AD+ARBs vs AD, p=0.02). No significant changes were observed in OS, inflammation, or PHF-tau and amyloid load in AD brains treated with ARBs. Our results highlight the impact of ARBs on the brains of cognitively intact and AD older individuals.

Accelerometer-Derived Patterns of Physical Activity and Incident Frailty

Low physical activity (PA) is a common phenotype of frailty, but whether disengagement of daily lifestyle PA signals impending frailty remains unexplored. Using STURDY (Study to Understand Fall Reduction and Vitamin D in You) data from 499 robust/prefrail adults (mean age=76 + 5 years; 42% women), we examined whether accelerometer patterns (activity counts/day, active minutes/day, and activity fragmentation) were prospectively associated with incident frailty over 2 years of follow-up; 48 (10%) participants developed frailty. In Discrete-Cox hazard models adjusted for demographics, medical conditions, and device wear days, every 30 min/day higher baseline active time, 100,000 more activity counts/day, and 1% lower activity fragmentation was associated with a 13% (p=0.003), 10% (p=0.001), and 8% (p&lt;0.001) lower risk of frailty, respectively. Our results show that both reduced amounts and fragmented patterns of daily PA captured from accelerometry are associated with phenotypic frailty and might signal frailty onset.

Characterization of a Mouse Model of Inducible Frailty: The Humanized IL-6 Mouse

The cytokine interleukin-6 (IL-6) has pleiotropic effects in aging and is elevated in frail older adults. We have developed a conditional mouse model to better characterize the role of IL-6 in promoting frailty and age-related mitochondrial dysregulation. The human IL-6 (hIL-6) knock-in mouse (TetO-hIL6) was developed utilizing CRISPR/Cas9 technology with transgene donor vector containing a tetracycline response element promoter driving expression of hIL-6 cDNA. Male TetO-hIL6 mice were treated with doxycycline-containing water for six weeks starting at 8 months old. RNAseq analysis of whole blood demonstrated significant upregulation of pro-inflammatory related markers at 6 weeks compared to baseline and upregulated cell proliferation and metabolism pathways. Physical testing of TetO-hIL6 mice before and after hIL-6 induction demonstrated decreased grip strength (p =0.003), decreased running capacity (p = 0.02), and 40% increase in falls off of the treadmill (p = 0.001). Induced mice also demonstrated decreased basal body temperature (p &lt; 0.001). Given the significant dysregulation of metabolism-related genes in RNAseq analysis and changes in basal body temperature following hIL-6 induction, we next performed untargeted metabolomics on plasma from mice at baseline and 6 weeks post-induction to better evaluate metabolic changes associated with hIL-6 elevation. We found changes in key serum metabolites, including circulating adenosine triphosphate (56% reduction, p = 0.02), pyruvate (35% reduction, p = 0.0006), alpha-ketoglutarate (47% reduction, p = 0.04), and succinate (306% increase, p = 0.001). The TetO-hIL6 mouse model allows for induction of hIL-6 at various timepoints across the lifespan and demonstrates features of a frailty phenotype.

Transplant Centers That Measure Frailty as Part of Clinical Practice Have Better Outcomes

Frailty predicts adverse outcomes for kidney transplant (KT) patients; yet the impact of clinical assessments of frailty on center-level outcomes remains unclear. We sought to test whether KT centers that measure frailty as part of clinical practice have better pre- and post-KT outcomes. We conducted a survey of US transplant centers (11/2017-4/2018), 132 KT centers (response rate=65.3%) reported frequencies of frailty assessment at candidacy evaluation and KT admission. Center characteristics and clinical outcomes were gleaned from the national registry (2017-2019). Poisson regression was used to estimate incidence rate ratios (IRRs) of waitlist mortality rate and transplantation rate in candidates and graft loss rates in recipients by frequency of frailty assessment. All models were adjusted for case mix and center characteristics. Given similar center characteristics, centers assessing frailty at evaluation had a lower waitlist mortality rate (always=3.5, sometimes=3.2, never=4.1 deaths per 100 person-years). After adjustment, centers assessing frailty at evaluation had a lower rates of waitlist mortality (always IRR=0.91, 95% CI:0.84-0.99; sometimes=0.89, 95% CI:0.83-0.96) and transplantation (always IRR=0.94, 95% CI:0.91-0.97; sometimes=0.88, 95% CI:0.85-0.90) than those never assessing frailty. Centers that always assessed frailty at KT admission had 0.71 (95% CI:0.54-0.92) times the rate of death-censored graft loss than their counterparts never assessing frailty. Assessing frailty at evaluation is associated with lower transplantation rate but better waitlist survival; centers always assessing frailty at admission are likely to have better graft survival. Research is needed to explore how routine assessment of frailty in other clinical practices benefits broader patient populations.

2015-2016 Normative Data for the 3-m Usual Walk, Five Repeated Chair Stands, and Static Balance Components of the SPPB Among U.S. Older Adults Across Two Nationally Representative Data Sets: NSHAP and NHATS

OBJECTIVES

Our primary objective was to examine the distribution of 3-m usual walk, five repeated chair stands, and three static balance stance performances among age and gender subgroups of adults at least 65 years in two national data sets. We secondarily determined whether demographic-function associations varied across data sets, birth cohorts, or models incorporating data from those "unable to do" tasks.

METHODS

Two nationally representative data sets were used to generate survey weight-adjusted performance distributions: the 2015-2016 National Social Life Health and Aging Project and the 2016 National Health and Aging Trends Study. We then regressed walk and chair stand performance on age, gender, and race/ethnicity, examining differences across data sets, birth cohorts (1920-1947, 1948-1965), and before/after incorporating the "unable to do" performers.

RESULTS

Findings confirmed the gradual decline in function with age and allowed estimation of "relative" performance within age/gender subgroups. Data set distribution differences were noted, possibly due to recruitment, eligibility, and protocol variations. Demographic associations were similar across data sets but generally weaker among the 1948-1965 cohort and in models including the sizable "unable to do" group.

DISCUSSION

We present the largest, most current Short Physical Performance Battery reference data in U.S. adults aged 65 or older. Findings support standardization of administration protocols in research and clinical care and differentiating absolute from relative performance.

Valsartan and Sacubitril Combination Treatment Enhances Collagen Production in Older Adult Human Skin Cells

Metformin is being deployed in clinical trials to ameliorate aging in older humans who do not have diabetes. In C. elegans, metformin treatment at old ages exacerbated mitochondrial dysfunction, led to respiratory failure, and shortened lifespan. Metformin is a commonly used, well-tolerated treatment for diabetes in older adults. Mitochondrial effects of metformin treatment in aged mammals has not been sufficiently investigated. We hypothesized that metformin treatment would not be toxic to older mammals. To define a therapeutic dose in aged hybrid rats, we evaluated two doses of metformin (0.1%, 0.75% of the diet) at 30-months of age. Body mass decreased at the 0.75% dose. Neither dose affected mortality between 30- and 34-months of age. We assessed mitochondrial quality, quantity, and function in aged rats treated with metformin at the 0.75% dose by measuring mitochondrial DNA copy number, deletion mutation frequency, and respirometry in skeletal muscle and heart. In skeletal muscle, we observed no effect of metformin on quadriceps mass, mtDNA copy number or deletion frequency. In the heart, metformin treated rats had higher mtDNA copy number, lower cardiac mass and no effect on deletion frequency. Metformin treatment resulted in lower mitochondrial complex I activity in both heart and quadriceps. Metformin did not compromise mitochondrial integrity, was well tolerated, and may have cardiac benefits to rats at old ages.

Genes Contributing to Resilience and Sensitivity to Lisinopril at Old Age: Clinical Translation of GWA in Drosophila

Despite impressive results in restoring physical performance in rodent models, treatment with Renin-Angiotensin System (RAS) inhibitors such as Lisinopril have highly mixed results in humans, likely, in part, due to genetic variation in human populations. To date, the genetic determinants of responses to drugs such as RAS inhibitors remain unknown. Given the complexity of the relationship between physical traits and genetic background, genomic studies which predict genotype- and age-specific responses to drug treatments in humans or vertebrate animals are difficult. Here, using 126 genetically distinct lines of Drosophila, we tested the effects of Lisinopril on climbing speed and endurance at young and old age (N=14,310). Our data show that functional response and sensitivity to Lisinopril ranges from significant protection against physical decline (8–100% faster, P< 0.0001) to increased weakness (P< 0.0001) depending on both genotype and age (P< 0.0001). Genome-wide analyses revealed little to no overlap in candidate polymorphisms influencing sensitivity between ages nor between treatments within each age. Furthermore, network analyses led to identification of evolutionarily conserved genes in the WNT signaling pathway as being significantly associated with variations in sensitivity to Lisinopril. Genetic knockdown of Axin, frizzled, nemo, and wingless, genes with human orthologs AXIN1, FZD1, NLK, and WNT1, respectively, abolished the effects of Lisinopril treatment. Our results implicate these genes as contributors to the genotype- and age-specific effects of Lisinopril treatment and as potential therapeutic targets for improvement of resiliency. Our approach should be widely applicable for identifying genomic variants that predict age-dependent responses to pharmaceutical treatments.

Losartan Mitigates Oxidative Stress in the Brains of Aged IL10-/- Mice

Chronic inflammation has been linked to frailty and declined cognition in older adults. Activation of the renin-angiotensin system (RAS) through the angiotensin Type1 receptor (AT1R) has been suggested as a contributory factor that links both inflammation and aging. Here we examined the impact of 4 weeks of oral Losartan treatment on IL10-/- mice brains, a mouse model of chronic inflammation and frailty. Frontal cortex, cerebellar, and hippocampal tissue of aged (100 weeks old) male IL10-/- mice were studied. Western blot techniques were employed to quantify changes in brain AT1R, nitrotyrosine (NT) as an oxidative stress marker, and Tau proteins. Our data show that aged IL-10 mice have significantly higher levels of AT1R in the cortex tissue but not in cerebellar or hippocampal tissue compared to age and sex-matched WT mice (0.63 + 0.35 vs 1.5 + 0.54, WT vs IL10, respectively, P&lt;0.004). When treated with LOS, brain cortical tissue of IL10 -/- mice showed significant decreases in levels of AT1R (1.5 + 0.54 vs 0.98 + 0.50, IL10 vs LOS treated IL10, respectively, P&lt;0.04), NT (0.72 + 0.12 vs 0.42 + 0.10, IL10 vs LOS treated IL10, respectively, P&lt;0.009), and Tau protein (1.3 + 0.31 vs 0.15 + 0.08, IL10 vs LOS treated IL10, respectively, P&lt;0.004) as compared to control IL10-/- mice. Losartan treatment had no significant effect on hippocampal AT1R or NT levels. Our results highlight the impact of Losartan, a drug commonly prescribed for the treatment of high blood pressure, on the brain-specific angiotensin system and its downstream effects on brain oxidative stress and Tau pathology.

Telomere Length and the Transition to Family Caregiving in the REGARDS Study

An increase in life expectancy and an aging population has resulted in increased risks and prevalence of age-related diseases. Previous studies have shown that factors, such as chronic stress, are associated with shorter telomere length. When telomeres become critically short, cells enter a state of senescence, which is a hallmark of aging. Several prior studies examining the relationship between caregiving and telomere length have reported mixed results. The present study utilized data from the Caregiving Transitions Study, an ancillary study to the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study. The difference in telomere length across an average ~8.6 years was compared between 235 incident caregivers and 229 controls. Telomere length was determined using the qPCR telomere-to-single copy gene (IFNB1) ratio (T/S) for each participant at both baseline and follow-up timepoints. Regression models controlling for age, sex, race, and baseline telomere length examined the association between caregiving status (exposure) and the telomere length change (□T/S). Sensitivity models adjusted for potential lifestyle and socioeconomic factors, including income, education, BMI, cigarette smoking, and alcohol use. We did not observe a significant association between □T/S and caregiving (beta=0.041, p=0.615). Adding lifestyle and socioeconomic factors did not change the null relationship (beta=0.062, p=0.455). In conclusion, this study provides evidence against an association between caregiving and the change in telomere length. Ultimately, more research to address the complex relationship between caregiving and telomere attrition is needed in order to prevent or reduce adverse outcomes and improve the well-being of caregivers and care recipients.

Chronic Inflammation and the Acceleration of Chronic Disease States

The chronic activation of the immune system is commonly observed in older adults, and is highly associated with multiple chronic disease states and Geriatric syndromes including physical frailty, sarcopenia and mild cognitive impairment. Chronic inflammation is multifactorial, and the individual inflammatory mediators that drive the development and propagation of disease states impact normal tissue homeostasis as well as stem cell vitality. This session will discuss age-related etiologies of chronic inflammation and specific inflammatory mediators and their measurement, including Tumor Necrosis Factor (TNF) alpha and its receptors. Inflammation-driven molecular pathways that most impact relevant chronic disease states such as the tryptophan degradation pathway, and its relationship to pathophysiological changes, will also be considered. Finally, discussion of potential treatment modalities, including several emerging from Geroscience research, will be described as will their impact on chronic disease states.

Objectively measured patterns of daily physical activity and phenotypic frailty

BACKGROUND

Self-reported low physical activity is a defining feature of phenotypic frailty but does not adequately capture physical activity performed throughout the day. This study examined associations between accelerometer-derived patterns of routine daily physical activity and frailty.

METHODS

Wrist accelerometer and frailty data from 638 participants (mean age 77 (SD=5.5) years; 44% women) were used to derive five physical activity metrics: active minutes/day, sedentary minutes/day, total activity counts/day, activity fragmentation (reciprocal of the average active bout length) and sedentary fragmentation (reciprocal of the average sedentary bout length). Robust, pre-frail and frail statuses were identified using the physical frailty phenotype defined as having 0, 1-2, or ≥3 of the following criterion: weight loss, exhaustion, slowness, self-reported low activity, and weakness. Frailty was collapsed into not frail (robust and prefrail) and frail, and each frailty criteria was dichotomized. Multiple logistic regression was used to model each accelerometer metric. Separate frailty criteria and interactions with age and sex were also examined.

RESULTS

With higher amounts and intensity of daily activity (more active minutes, fewer sedentary minutes, higher activity counts) and lower activity fragmentation, the odds of frailty were lower compared to robust/prefrail states (p<0.02 for all). For interactions, only an age by sedentary fragmentation interaction on the odds of frailty was observed (p=0.01). For each separate criteria, accelerometer metrics were associated with odds of slowness, low activity, and weakness.

CONCLUSION

Less favorable patterns of objectively measured daily physical activity are associated with frailty and the components of slowness, low self-reported activity, and weakness.

Risk Factors for Non-Resilient Outcomes in Older Adults after Total Knee Replacement in the FORCE-TJR Cohort

BACKGROUND

Total knee replacement (TKR) is a common procedure in older adults. Physical resilience may be a useful construct to explain variable outcomes. We sought to define a simple measure of physical resilience and identify risk factors for non-resilient patient outcomes.

METHODS

Secondary analysis of FORCE-TJR cohort study, a prospective registry of total joint replacement. Analysis included 7,239 adults ages 60 or older who underwent TKR between 2011- 2015. Measures included sociodemographic and health factors. Outcomes were categorized as physically resilient versus non-resilient based on the change from baseline to 1-year follow up for three patient-reported outcomes: the physical component summary (PCS), bodily pain (BP), and vitality (VT) from the Short Form-36 (SF-36) subcomponent scores, at pre-op and 1-year post-procedure. Associations were expressed as relative risk of physically non-resilient outcomes using generalized linear regression models, with Poisson distribution and log link.

RESULTS

Age, BMI, and Charlson Comorbidity Index (CCI) were associated with increased risk of physically non-resilient outcomes across PCS, BP, and VT: age, per 5-years for PCS (RR=1.18[1.12-1.23]), BP (RR=1.06[1.01-1.11), and VT (RR=1.09[1.06-1.12]); BMI, per 5 Kg/m 2, for PCS (RR=1.13[1.07-1.19]), BP (RR=1.06[1.00-1.11]), and VT (RR=1.08[1.04-1.11]); and CCI for PCS CCI=1 (RR=1.38[1.20-1.59]), CCI=2-5 (RR=1.59[1.35-1.88]), CCI>=6 (RR=1.55[1.31-1.83]. Household-income >$45,000 associated with lower risk for PCS (RR=0.81[0.70-0.93]), BP (RR=0.80[0.69-0.91],), and VT (RR=0.86[0.78-0.93]).

CONCLUSIONS

We operationalized physical resilience and identified factors predicting resilience after TKR. This approach may aid clinical risk stratification, guide further investigation of causes, and ultimately aid patients through the design of interventions to enhance physical resilience.

Development and Validation of an Inflammatory-Frailty Index for Kidney Transplantation

BACKGROUND

Physical frailty phenotype is characterized by decreased physiologic reserve to stressors and associated with poor outcomes, such as delirium and mortality, that may result from post-kidney transplant (KT) inflammation. Despite a hypothesized underlying pro-inflammatory state, conventional measures of frailty typically do not incorporate inflammatory biomarkers directly. Among KT candidates and recipients, we evaluated the inclusion of inflammatory biomarkers with traditional physical frailty phenotype components.

METHODS

Among 1154 KT candidates and recipients with measures of physical frailty phenotype and inflammation (interleukin 6 [IL6], tumor necrosis factor alpha [TNFα], C-reactive protein [CRP]) at 2 transplant centers (2009-2017), we evaluated construct validity of inflammatory-frailty using latent class analysis. Inflammatory-frailty measures combined 5 physical frailty phenotype components plus the addition of an individual inflammatory biomarkers, separately (highest tertiles) as a sixth component. We then used Kaplan-Meier methods and adjusted Cox proportional hazards to assess post-KT mortality risk by inflammatory-frailty (n = 378); Harrell's C-statistics assessed risk prediction (discrimination).

RESULTS

Based on fit criteria, a 2-class solution (frail vs nonfrail) for inflammatory-frailty was the best-fitting model. Five-year survival (frail vs nonfrail) was: 81% versus 93% (IL6-frailty), 87% versus 89% (CRP-frailty), and 83% versus 91% (TNFα-frailty). Mortality was 2.07-fold higher for IL6-frail recipients (95% CI: 1.03-4.19, p = .04); there were no associations between the mortality and the other inflammatory-frailty indices (TNFα-frail: 1.88, 95% CI: 0.95-3.74, p = .07; CRP-frail: 1.02, 95% CI: 0.52-2.03, p = .95). However, none of the frailty-inflammatory indices (all C-statistics = 0.71) improved post-KT mortality risk prediction over the physical frailty phenotype (C-statistics = 0.70).

CONCLUSIONS

Measurement of IL6-frailty at transplantation can inform which patients should be targeted for pre-KT interventions. However, the traditional physical frailty phenotype is sufficient for post-KT mortality risk prediction.

Early detection of accelerated aging and cellular decline (AACD): A consensus statement

The cellular hallmarks of accelerated aging and their clinical expression may be grouped using the terms 'accelerated aging and cellular decline' (AACD) and/or 'age-associated cellular decline'. This construct is designed to capture the biological background predisposing the development of age-related conditions. By classifying risk factors, early indicators, and clinical differentiators of AACD through expert consensus, this study aimed to identify the signs, symptoms, and markers indicative of AACD. In doing so, this work paves the way for future implementation of the AACD concept in the clinical and research settings. An interdisciplinary panel of experts with clinical and research expertise was selected to participate in a virtual workshop to discuss AACD. A modified nominal group technique was used to establish consensus among the group. An extended group of international experts critically reviewed an early draft of the manuscript, and their feedback was then incorporated into the model. Experts identified 13 factors predisposing to or clinically manifesting AACD. Among these, chronic diseases, obesity, and unfavorable genetic background were considered as the most important. There was a consensus that a gradual and nonspecific development often characterizes AACD, making its clinical detection potentially challenging. In addition, signs and symptoms might have multifactorial causes and overlapping origins, such as genetic and epigenetic predispositions. As a result, an initial checklist was outlined, listing clinical factors of special relevance (e.g., fatigue, low quality of sleep, and low mood) to represent early manifestations of the organism's exhaustion, which are also frequently neglected in the clinical setting. Differentiating AACD from other conditions is essential. The use of a combination of biomarkers was proposed as a viable method in a two-step process of differentiation: 1) identification of early AACD clinical indicators, followed by 2) symptom and biomarker confirmation with a focus on system domains (to be potentially targeted by future specific interventions). Although the AACD construct is not yet ready for routine use in clinical practice, its operationalization may support the early identification of age-related conditions (when this might still be amenable to reversion) and also encourage preventative interventions. Further investigation is needed to establish specific biomarkers that confirm independent risk factors for AACD and provide a more definitive structure to the concept of AACD (and age-associated cellular decline).

Fractional re-distribution among cell motility states during ageing

Ageing in humans is associated with the decreased capacity to regulate cell physiology. Cellular properties, such as cell morphology and mechanics, encode ageing information, and can therefore be used as robust biomarkers of ageing. Using a panel of dermal fibroblasts derived from healthy donors spanning a wide age range, we observe an age-associated decrease in cell motility. By taking advantage of the single-cell nature of our motility data, we classified cells based on spatial and activity patterns to define age-dependent motility states. We show that the age-dependent decrease in cell motility is not due to the reduced motility of all cells, but results from the fractional re-distribution among motility states. These findings highlight an important feature of ageing cells characterized by a reduction of cellular heterogeneity in older adults relative to post-adolescent/adults. Furthermore, these results point to a mechanistic framework of ageing, with potential applications in deciphering emergent ageing phenotypes and biomarker development.

The physical frailty syndrome as a transition from homeostatic symphony to cacophony

Frailty in aging marks a state of decreased reserves resulting in increased vulnerability to adverse outcomes when exposed to stressors. This Perspective synthesizes the evidence on the aging-related pathophysiology underpinning the clinical presentation of physical frailty as a phenotype of a clinical syndrome that is distinct from the cumulative-deficit-based frailty index. We focus on integrating the converging evidence on the conceptualization of physical frailty as a state, largely independent of chronic diseases, that emerges when the dysregulation of multiple interconnected physiological and biological systems crosses a threshold to critical dysfunction, severely compromising homeostasis. Our exegesis posits that the physiology underlying frailty is a critically dysregulated complex dynamical system. This conceptual framework implies that interventions such as physical activity that have multisystem effects are more promising to remedy frailty than interventions targeted at replenishing single systems. We then consider how this framework can drive future research to further understanding, prevention and treatment of frailty, which will likely preserve health and resilience in aging populations.

Air Pollution and Gerontological Constructs Among Patients With End-Stage Kidney Disease

Frailty is triggered by inflammatory pathways among patients with end-stage kidney disease (ESKD). Exposure to air pollution is associated with increased inflammation and as such may be a determinant of frailty in patients with ESKD. Therefore, we sought to estimate the impact of household-level exposure to fine particulate matter (particles <2.5μm in diameter [PM2.5]) on frailty and other gerontological constructs among patients with ESKD. We leveraged a prospective, two-center cohort study of 1,482 adults with ESKD (2014-2019) from 40 US states. The physical frailty phenotype (PFP), SPPB, ADL/IADL dependence and 3MS global cognitive impairment were assessed at transplant evaluation. Household-level air pollution was estimated as annual average PM2.5 concentrations at each participant’s address using SEDAC national air pollution data. We estimated the odds of these gerontologic constructs using adjusted logistic regression by quartiles of PM2.5 concentrations accounting for confounders including socioeconomic status. Compared to patients with PM2.5 concentrations in the lowest quartile (<9.3µg/m3), those with exposure to the 3rd quartile (10.0-11.1µg/m3) had 1.50-fold (95%CI:1.04-2.17) increased odds of frailty. However, exposure to PM2.5 concentrations in the second (9.3-10.0µg/m3) and fourth quartiles (>11.1µg/m3) were not significant. Those with PM2.5 in the 3rd (OR=1.60, 95%CI:1.19-2.16) or 4th (OR=1.61, 95%CI:1.20-2.16) quartile had an increased risk of having dependence in ADLs or IADLs. PM2.5 was not associated with SPPB or cognitive impairment. Among ESKD patients, fine particulate matter was associated with greater frailty and dependence burden, although these association may not be linear. Further study of the role of inflammation on these associations are needed.

The Measurement of Physical Resiliencies: Conceptualization, Study Design, and Early Data

This talk presents the conceptual framework, study design, and pilot data for the Study of Physical Resilience and agING (SPRING). SPRING aims to develop signatures of physical resilience in older adults who will undergo clinical stressors; validate the signatures’ ability to distinguish those who will respond resiliently; and characterize underlying physio-biological determinants. The underlying physiology is conceptualized as a dynamical system, and resilience, as a property thereof. The SPRING pilot has assessed n=77 older adults before, during and repeatedly after experiencing knee replacement surgery, incident hemodialysis, or bone marrow transplant; a confirmatory study evaluating n=100 older adults per each of these stressors is underway. Resilience signatures grounded in dynamical data from multiple stress-response assessments will be presented. So also will resilience phenotypes—longitudinal functional trajectories over the study visits: These show considerable heterogeneity within and across stressors. If successful, our study will open the way for interventions to bolster resiliency. Part of a symposium sponsored by Epidemiology of Aging Interest Group.

Resilience in Incident Hemodialysis: Characterization and Outcome Prediction

The Resiliency in Dialysis Initiation (ReDI) Study aims to develop physical resilience signatures in older adults initiating hemodialysis. Study design—comprising a pilot, confirmatory study, and secondary data analyses—will be presented. So also will a method for characterizing resilience phenotypes—using mixed-model analysis of SF-36 subscale trajectories—among participants of age 55 and older who had undergone hemodialysis in the Choices for Healthy Outcomes in Caring for ESRD study (n=485). Analyses revealed stable, improving, and declining phenotypes. In Cox models, both baseline phenotypic status and trajectory type predicted mortality after adjusting for age, CVD status, and CHF (global Wald test for trajectory type P-value=0.020 for vitality; 0.030 for general health). These analyses evidence usefulness of resilience phenotypes as markers of adverse outcome risk and foreshadow application to novel ReDI data.

Self-Efficacy Proxy Predicts Physical Frailty Incidence Over 8 Years in Non-Institutionalized Older Adults

Physical frailty is defined as a syndrome of decreased physiologic reserve conferring vulnerability to functional decline, mortality and other adverse outcomes in response to a stressor. One potential modifiable risk factor of frailty is self-efficacy, which is confidence in one’s ability to perform well at a task or domain in life. Self-efficacy is associated with improved health behavior and decreased chronic disease burden but has not been studied extensively in frailty research. Therefore, the purpose of this study was to evaluate a general self-efficacy proxy measure’s ability to predict frailty in a nationally representative sample of older adults using data from the National Health and Aging Trends Study (NHATS) collected from 2011-2018. 4,835 older adults (65+) were dichotomized into low and high self-efficacy groups using the one-item self-efficacy proxy measure in NHATS. The Physical Frailty Phenotype was used to assess frailty. A discrete time hazard model was used to obtain incident hazard ratios of frailty in two models. Model 1 was adjusted for age, race, sex, education and income. Model 2 contained Model 1 covariates and activities of daily living and co-morbidities. We found that low self-efficacy predicted a 41% increased risk of developing frailty over 8 years after adjustment for socio-demographics (P<0.0001) and a 27% risk of incident frailty after further adjustment for activities of daily living and co-morbidities (P=0.004). This study provides preliminary evidence that self-efficacy may be a key modifiable element to incorporate into multi-modal frailty interventions.

Are all homebound older adults frail?

Seven million adults in the United States are homebound and suffer the negative, powerful synergies of multiple chronic conditions, functional impairment, social stressors, and limited social capital. The prevalence of frailty in this vulnerable homebound population is unknown. Using representative data from the National Health and Aging Trends study (NHATS) study linked to Medicare claims (n=4756) we sought to assess the prevalence of frailty in the homebound population (n=361). Among the homebound, 68.5% met the frailty criteria compared to 12.3% of the non-homebound population. The frail homebound had lower educational attainment, were more likely to live alone, self-reported poorer health and more chronic physical and mental health conditions than the non-frail homebound (p<0.05 for all). Frail homebound older adults utilized more health services utilization than non-frail homebound and were twice as likely to be hospitalized (49.8% versus 28.0%, p=0.004).

The Transition to Family Caregiving: Does It Affect Biomarkers of Aging?

Blood samples were collected from participants in the REGARDS study on two separate occasions. No participants in the Caregiving Transitions Study were caregivers at the first blood draw, but 251 became caregivers before the second blood draw 9 years later. These caregivers were matched with 251 noncaregiving controls. Six circulating biomarkers of inflammation (e.g., CRP, IL-6, TNFR1) and a measure of cellular aging (leukocyte telomere length) were assessed at both blood draws. All biomarkers except CRP showed overall aging effects (ps < 0.001). Caregivers had a small but significantly greater increase in TNFR1 levels (p = 0.03) than controls, but no significant differential changes were found on the other 5 inflammatory biomarkers or on telomere length. Preliminary findings from latent variable models indicated good model fit and found caregivers to be 0.27 SDs lower than controls on a latent construct of inhibitory, regulatory feedback of systemic inflammation (p = 0.03).

Risk Factors for Poor Recovery After Total Knee Replacement Among Older Adults in the FORCE-TJR Cohort

Total knee replacement (TKR) is a common procedure in older adults with broad variability in outcomes. We sought to identify factors that contribute to resilient outcomes in 7,239 older adults (age 60 or older) who underwent TKR in the TJR-FORCE, a prospective registry of total joint replacement. Outcomes utilized were bodily pain and physical component score (PCS) from the Short Form 36 Health Survey (SF-36), at pre-op, 1-year, and 2-year post-procedure. Participants were grouped according to their outcome trajectories as “improving”, “worsening”, “variable,” or “stable.” Multinomial regression (with 4 outcome categories) was used to evaluate demographic risk factors (age, gender, BMI, marital status, education, smoking history, comorbidity count, household income). Older age, larger comorbidity count, low-income, smoking, and being unmarried were significant risk factors for poor recovery (not “improving”) in terms of bodily pain and physical component score. Next steps include evaluating risk factors for resilience outcomes in prospective studies.

High coping self-efficacy associated with lower odds of pre-frailty/frailty in older adults with chronic disease

OBJECTIVES

Frailty affects an estimated 15% of community dwelling older adults. Few studies look at psychosocial variables like self-efficacy (confidence to perform well at a particular task or life domain) in relation to frailty. The purpose of this study was to evaluate associations between pre-frailty/frailty and self-efficacy.

METHODS

This cross-sectional study enrolled community dwelling older adults 65 and older (N = 146) with at least one chronic condition. Scales included: 5-item FRAIL scale (including measures of Fatigue, Resistance, Ambulation, Illnesses, and Loss of weight); coping self-efficacy used to measure confidence in one's ability to problem solve, emotionally regulate and ask for support when problems in life occur; illness intrusiveness; patient health questionnaire to assess depressive symptoms; financial strain; life events count; social support; heart rate; tobacco use and body mass index. Logistic regression was used for model development.

RESULTS

Roughly half (49.3%) of the participants were frail/pre-frail. High coping self-efficacy was associated with a 92% decreased odds of pre-frailty/frailty after adjustment for age, sex, race, co-morbidities, heart rate, a life events count, and body mass index. This relationship remained significant when illness intrusiveness and depression scores were added to the model (OR: 0.10; p-value = 0.014). Increases in age, co-morbidities, heart rate and body mass index were also significantly associated with higher adjusted odds of pre-frailty/frailty.

CONCLUSIONS

High coping self-efficacy was associated with greater odds of a robust state. Further consideration should be given to coping self-efficacy in frailty research and intervention development.

Kynurenines link chronic inflammation to functional decline and physical frailty

Chronic inflammation is associated with physical frailty and functional decline in older adults; however, the molecular mechanisms of this linkage are not understood. A mouse model of chronic inflammation showed reduced motor function and partial denervation at the neuromuscular junction. Metabolomic profiling of these mice and further validation in frail human subjects showed significant dysregulation in the tryptophan degradation pathway, including decreased tryptophan and serotonin, and increased levels of some neurotoxic kynurenines. In humans, kynurenine strongly correlated with age, frailty status, TNF-αR₁ and IL-6, weaker grip strength, and slower walking speed. To study the effects of elevated neurotoxic kynurenines on motor neuronal cell viability and axonal degeneration, we used motor neuronal cells treated with 3-hydroxykynurenine and quinolinic acid and observed neurite degeneration in a dose-dependent manner and potentiation of toxicity between 3-hydroxykynurenine and quinolinic acid. These results suggest that kynurenines mediate neuromuscular dysfunction associated with chronic inflammation and aging.

Tryptophan-related toxic metabolites known as kynurenines are altered with chronic inflammation, which damages nerves in aged and frail mice and humans.

Association of peripheral inflammatory markers with connectivity in large-scale functional brain networks of non-demented older adults

BACKGROUND

Systemic inflammation has emerged as a risk factor for cognitive decline and Alzheimer's disease, but inflammation's effect on distributed brain networks is unclear. We examined the relationship between peripheral inflammatory markers and subsequent functional connectivity within five large-scale cognitive networks and evaluated the modifying role of cortical amyloid and APOE ε4 status.

METHODS

Blood levels of soluble tumor necrosis factor-alpha receptor-1 and interleukin 6 were assessed in 176 participants (at baseline mean age: 65 (SD 9) years; 63% women; 85% cognitively normal, 15% mild cognitive impairment (MCI)) and were combined to derive an Inflammatory Index. Approximately six years later, participants underwent resting-state functional magnetic resonance imaging to quantify functional connectivity; a subset of 137 participants also underwent ¹¹C Pittsburgh compound-B (PiB) PET imaging to assess cortical amyloid burden.

RESULTS

Using linear regression models adjusted for demographic characteristics and cardiovascular risk factors, a higher Inflammatory Index was associated with lower connectivity within the Default Mode (β = -0.013; 95% CI: -0.023, -0.003) and the Dorsal Attention Networks (β = -0.017; 95% CI: -0.028, -0.006). The strength of these associations did not vary by amyloid status (positive/negative). However, there was a significant interaction between Inflammatory Index and APOE ε4 status, whereby ε4-positive participants with a higher Inflammatory Index demonstrated lower connectivity. Inflammatory Index was unrelated to connectivity within other large-scale cognitive networks (Control, Limbic, and Salience/Ventral Attention networks).

CONCLUSION

Peripheral pro-inflammatory signaling in older adults without dementia, especially among APOE ε4-positive individuals, is associated with altered connectivity within two large-scale cognitive networks.

Sarcopenia and health-related quality of life in older adults after transcatheter aortic valve replacement

BACKGROUND

Skeletal muscle wasting, or sarcopenia, affects a significant proportion of patients undergoing transcatheter aortic valve replacement (TAVR). However, its influence on post-TAVR recovery and 1-year health-related quality of life (HR-QOL) remains unknown. We examined the relationship between skeletal muscle index (SMI), post-TAVR length of hospital stay (LOS), and 1-year QOL.

METHODS

The study sample consisted of 300 consecutive patients undergoing TAVR from 2012 to 2018 who had pre-TAVR computed tomographic scans suitable for analysis of body composition. Skeletal muscle mass was quantified as cm² of skeletal mass per m² of body surface area from the cross-sectional computed tomographic image at the third lumbar vertebra. Sarcopenia was defined using established sex-specific cutoffs (women: SMI < 39 cm²/m²; men: < 55 cm²/m²). Multivariable linear regression analysis was used to determine the relationship between SMI, LOS, and HR-QOL using the Kansas City Cardiomyopathy Questionnaire.

RESULTS

Sarcopenia was present in most (59%) patients and associated with older age (82 vs 76 years; P < .001) and lower body mass index (27 vs 33 kg/m²; P < .001). There were no other differences in baseline clinical or echocardiographic characteristics among the 4 quartiles of SMI. SMI was positively correlated with LOS and 1-year QOL. After adjusting for age, gender, race, and body mass index, SMI remained a significant predictor of both LOS (P = .01) and 1-year QOL (P = .012). For every 10 cm²/m² higher SMI, there was an 8-point increase in Kansas City Cardiomyopathy Questionnaire score, a difference that is clinically meaningful.

CONCLUSIONS

Sarcopenia is prevalent in TAVR patients. Higher SMI is associated with shorter LOS and better 1-year HR-QOL. To achieve optimal TAVR benefits, further study into how body composition influences post-TAVR recovery and durable improvement in QOL is warranted.

Derivation of a measure of physiological multisystem dysregulation: Results from WHAS and health ABC

INTRODUCTION

Multifactorial biological processes underpin dysregulation over several individual physiological systems. However, it is challenging to characterize and model this multisystemic dysregulation and its relationship with individual physiologic systems. We operationalized a theory-driven measure of multisystem dysregulation and empirically tested for measurement differences by key characteristics.

METHODS

We used the Women's Health and Aging Studies (WHAS) I and II (N = 649), and the Health ABC study (N = 1515). Twelve biomarkers representing multiple systems including stress response (e.g., inflammation), endocrine system, and energy regulation were identified. A series of confirmatory factor analyses (CFA) were conducted to evaluate the interplay between physiological systems and underlying multisystem dysregulation. We evaluated convergent criterion validity of a score for multisystem dysregulation against the physical frailty phenotype, and predictive criterion validity with incidence of walking difficulty and mortality.

RESULTS

A bifactor CFA, a model in which dysregulation of individual systems proceeds independently of generalized dysregulation, fit data well in WHAS (RMSEA: 0.019; CFI: 0.977; TLI: 0.961) and Health ABC (RMSEA: 0.047; CFI: 0.874; TLI: 0.787). The general dysregulation factor was associated with frailty (OR: 2.2, 95 % CI: 1.4, 3.5), and elevated risk of incident walking difficulty and mortality. Findings were replicated in Health ABC.

DISCUSSION

Biomarker data from two epidemiologic studies support the construct of multisystem physiological dysregulation. Results further suggest system-specific and system-wide processes have unique and non-overlapping contributions to dysregulation in biological markers.

IL10 deficiency promotes alveolar enlargement and lymphoid dysmorphogenesis in the aged murine lung

The connection between aging-related immune dysfunction and the lung manifestations of aging is poorly understood. A detailed characterization of the aging IL10-deficient murine lung, a model of accelerated aging and frailty, reconciles features of both immunosenescence and lung aging in a coherent model. Airspace enlargement developed in the middle-aged (12 months old) and aged (20-22 months old) IL10-deficient lung punctuated by an expansion of macrophages and alveolar cell apoptosis. Compared to wild-type (WT) controls, the IL10-deficient lungs from young (4-month-old) mice showed increased oxidative stress which was enhanced in both genotypes by aging. Active caspase 3 staining was increased in the alveolar epithelial cells of aged WT and mutant lungs but was greater in the IL10-deficient milieu. Lung macrophages were increased in the aged IL10-deficient lungs with exuberant expression of MMP12. IL10 treatment of naïve and M2-polarized bone marrow-derived WT macrophages reduced MMP12 expression. Conditioned media studies demonstrated the secretome of aged mutant macrophages harbors reduced AECII prosurvival factors, specifically keratinocyte growth factor (KGF) and hepatocyte growth factor (HGF), promotes cell death, and reduces survival of primary alveolar epithelial cells. Compared to WT controls, aged IL10-deficient mice have increased parenchymal lymphoid collections comprised of a reduced number of apoptotic cells and B cells. We establish that IL10 is a key modulator of airspace homeostasis and lymphoid morphogenesis in the aging lung enabling macrophage-mediated alveolar epithelial cell survival and B-cell survival within tertiary lymphoid structures.