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.