Age-related Decrements Research Articles

Age Differences in Consulting Others During Decision Making.

Many choices are made in the context of one's social network, but age differences in consulting others during decision-making remain underexplored. This pre-registered study examined age differences in the composition of decision-related social networks and associated social preferences and motivations. Based on prior findings regarding age differences in information-seeking and socioemotional preferences, we predicted that with advanced age people would consult fewer and more emotionally close social partners, consult them less frequently, rate consultations as more helpful, and prioritize social goals during decision-making. An adult lifespan sample (N = 485; Mage = 51.08; SDage = 19.63, rangeage = 18-96 years) considered hypothetical choices and reported how many and what types of people they would consult and how often they would consult them. They also identified their most important decision consultants and evaluated interactions with those individuals. As predicted, age was associated with consulting fewer people less frequently and this was not explained by having a smaller range of potential consultants in one's network. Contrary to predictions, the proportion of close social partners in decision networks and the perceived helpfulness of consultants did not vary significantly by age. Moreover, older adults were less likely than younger adults to prioritize relationship quality over decision quality. Controlling for potential covariates did not diminish the observed age effects. These findings align with the prior literature on age-related decrements in pre-decisional information seeking but suggest that age-related preferences for close social partners and socioemotional goals do not extend to decision-related consultations.

Effect of age on ankle biomechanics and tibial compression during stair descent

BackgroundStress fracture is a concern among older adults, as age-related decrements in ankle neuromuscular function may impair their ability to attenuate tibial compressive forces experienced during daily locomotor tasks, such as stair descent. Yet, it is unknown if older adults exhibit greater tibial compression than their younger counterparts when descending stairs. Research questionDo older adults exhibit differences in ankle biomechanics that alter their tibial compression during stair descent compared to young adults, and is there a relation between tibial compression and specific changes in ankle biomechanics? MethodsThirteen young (18–25 years) and 13 older (> 65 years) adults had ankle joint biomechanics and tibial compression quantified during a stair descent. Discrete ankle biomechanics (peak joint angle and moment, and joint stiffness) and tibial compression (maximum and impulse) measures were submitted to an independent t-test, while ankle joint angle and moment, and tibial compression waveforms were submitted to an independent statistical parametric mapping t-test to determine group differences. Pearson correlation coefficients (r) determined the relation between discrete ankle biomechanics and tibial compression measures for all participants, and each group. ResultsOlder adults exhibited smaller maximum tibial compression (p = 0.004) from decreases in peak ankle joint angle and moment between 17 % and 34 % (p = 0.035), and 20–31 % of stance (p < 0.001) than young adults. Ankle biomechanics exhibited a negligible to weak correlation with tibial compression for all participants, with peak ankle joint moment and maximum tibial compression (r = -0.48 ± 0.32) relation the strongest. Older adults typically exhibited a stronger relation between ankle biomechanics and tibial compression (e.g., r = -0.48 ± 0.47 vs r = -0.27 ± 0.52 between peak ankle joint moment and maximum tibial compression). SignificanceOlder adults altered ankle biomechanics and decreased maximum tibial compression to safely execute the stair descent. Yet, specific alterations in ankle biomechanics could not be identified as a predictor of changes in tibial compression.

Impaired autophagy following ex vivo cooling of simulated hypothermic temperatures in peripheral blood mononuclear cells from young and older adults

Hypothermia is a critical consequence of extreme cold exposure that increases the risk of cold-related injury and death in humans. While the initiation of cytoprotective mechanisms including the process of autophagy and the heat shock response (HSR) is crucial to cellular survival during periods of stress, age-related decrements in these systems may underlie cold-induced cellular vulnerability in older adults. Moreover, whether potential sex-related differences in autophagic regulation influence the human cold stress response remain unknown. We evaluated the effect of age and sex on mechanisms of cytoprotection (autophagy and the HSR) and cellular stress (apoptotic signaling and the acute inflammatory response) during ex vivo hypothermic cooling. Venous blood samples from 20 healthy young (10 females; mean [SD]: 22 [2] years) and 20 healthy older (10 females; 66 [5] years) adults were either isolated immediately (baseline) for peripheral blood mononuclear cells (PBMCs) or exposed to water bath temperatures maintained at 37, 35, 33, 31, or 4 °C for 90 min before PBMC isolation. Proteins associated with autophagy, apoptosis, the HSR, and inflammation were analyzed via Western blotting. Indicators of autophagic initiation and signaling (LC3, ULK1, and beclin-2) and the HSR (HSP90 and HSP70) increased when exposed to hypothermic temperatures in young and older adults (all p ≤ 0.007). Sex-related differences were only observed with autophagic initiation (ULK1; p = 0.015). However, despite increases in autophagic initiators ULK1 and beclin-2 (all p < 0.001), this was paralleled by autophagic dysfunction (increased p62) in all groups (all p < 0.001). Further, apoptotic (cleaved-caspase-3) and inflammatory (IL-6 and TNF-α) signaling increased in all groups (all p < 0.001). We demonstrated that exposure to hypothermic conditions is associated with autophagic dysfunction, irrespective of age or sex, although there may exist innate sex-related differences in cytoprotection in response to cold exposure as evidenced through altered autophagic initiation.

Exploring Eating Habits, Healthy Food Awareness, and Inclination toward Functional Foods of Italian Elderly People through Computer-Assisted Telephone Interviews (CATIs).

The continuous increase in life expectancy leads to progressive population ageing, especially in most developed countries. A healthy diet and better consumption of tailored functional foods may represent one of the strategies to postpone or slow down age-related decrements, thus increasing healthy ageing and reducing healthcare costs. This research aimed to explore elderly people's (>65 years old) eating habits and assess their awareness of food-health correlation. In total, 511 Italian seniors answered a CATI (computer-assisted telephone interviewing) questionnaire through a deep, telephone interview to collect information about dietary habits, healthy food awareness, and inclination for functional foods. The elderly were divided into four groups according to gender and age: Early Elderly Female (n = 130), Early Elderly Men (n = 109), Late Elderly Female (n = 157), and Late Elderly Men (n = 115). The groups provided a positive self-assessment of health status and individual diet healthiness, which were both considered over "good enough" (5 on 10-point scale) and showed food consumption habits in line with the Mediterranean Diet (MD) principles. The daily diet was based on fruits, vegetables, bread, and pasta, with extra virgin olive oil as the main fat source, all over "often" consumed (4 on 5-point scale). Old people also showed awareness of different food's healthy properties. Specifically, females were more aware of food's impact on health, considered close to "extremely healthy" (9 on 10-point scale), and strictly followed a MD. Participants also expressed optimistic expectations about functional food efficiency, evaluated as close to "extremely desirable" (8 or 9 on 10-point scale), against age-related problems, highlighting the most important as diabetes, overweight, intestine problems, and low mood. The interviewed elderly were also involved in virtual functional food co-creation, indicating through a basic matrix which, among the most familiar foods, could be the ideal functional food, focusing on fruitsand vegetables. A pleasant odor/flavor, a liquid texture, and a warm serving temperature rather than cold characterized the virtual functional food created. Other positive attributes were liquid and thickness, while acidity and bitterness were among the least desired traits. These findings show how elderly people, despite predictable age-related sensory and cognitive loss, when properly involved and guided, can help envision foods that fit their needs and desires.

Psychometric properties and adaptation of the Virtual Week in a sample of French young and older adults

IntroductionProspective memory (PM) is the ability to remember to perform activities to be carried out in the future. This form of future-oriented cognition is crucial in daily life for managing activities as well as for maintaining independence and autonomy, especially during aging. This study focused on the Virtual Week, an assessment instrument of PM in which participants are asked to remember to perform lifelike activities. ObjectivesThe present study aimed to provide a French adaptation of the Virtual Week and to test whether this adaptation was able to identify age-related declines in PM. We also evaluated the internal consistency and the split-half reliability of the adapted version. MethodWe collected data from 44 healthy younger (18–30 years) and 44 healthy older adults (65–80 years) and tested whether the French version of the Virtual Week was sensitive to decline in PM performance in older adults, in accordance to theories on normal aging and PM. ResultsThe French Virtual Week was able to detect age-related decrements in PM and demonstrated strong psychometric properties. ConclusionThese findings broadly support the sensitivity and the reliability of the French adaptation of the Virtual Week, thus encouraging its use in current clinical practice.

Financial Hardship and Age-Related Decrements in Kidney Function Among Black and White Adults in the Midlife in the United States Study.

This analysis examined if financial hardship was associated with age-related decrements in kidney function using a material-psychosocial-behavioral framework. We also tested if this association was mediated by comorbidity of cardiometabolic risk factors (obesity, elevated blood pressure, and insulin resistance). Data from 1361 non-Hispanic Black and White adults (ages 26-94 years; non-Hispanic Black = 258) were obtained from the Wave 3 and Refresher phases of the Midlife in the United States project. Kidney function was based on serum creatinine-based estimated glomerular filtration rate (eGFR; Chronic Kidney Disease Epidemiology Collaboration formula without race adjustment). Financial hardship was evaluated in three domains: material (income to poverty line ratio, health insurance coverage, and public/government financial assistance), psychological (perceived financial status, control over financial status, and perceived financial strains), and behavioral responses (financial adjustment/coping such as sold possessions and cutting back on spending). More severe financial hardship (overall score and in each domain) was associated with age-related decrements in eGFR, even after adjusting for sociodemographic, education, and health-related covariates. The association between financial hardship and age-related decrements in eGFR was conditional on sex but not race. Finally, cardiometabolic risk factors mediated the association between financial hardship and age-related decrements in eGFR. These findings affirm the negative effects of financial hardship on age-related decrements in renal clearance. In addition to incorporating traditionally used indicators of SES, such as education and income, future research on social hallmarks of aging should also consider the role of financial hardship on the aging process and age-related diseases.

Aging and sympathetic transduction to blood pressure in humans: methodological and physiological considerations.

Recent reports suggest that quantification of signal-averaged sympathetic transduction is influenced by resting muscle sympathetic nerve activity (MSNA) and burst occurrence relative to the average mean arterial pressure (MAP). Herein, we asked how these findings may influence age-related reductions in sympathetic transduction. Beat-to-beat blood pressure and MSNA were recorded during 5 min of rest in 27 younger (13 females: age, 25 ± 5 yr; BMI, 25 ± 4 kg/m2) and 26 older (15 females: age, 59 ± 5 yr; BMI, 26 ± 4 kg/m2) healthy adults. All MSNA bursts were signal averaged together. Beat-to-beat MAP values were then split into low (T1), middle (T2), and high (T3) tertiles, and signal-averaged transduction was calculated within each tertile. Resting MSNA was higher in older adults and MAP was similar between groups. Older adults exhibited blunted overall MAP transduction (younger, Δ1.5 ± 0.6 vs. older, Δ0.9 ± 0.7 mmHg; P = 0.005), which was irrespective of relation to prevailing MAP. A greater proportion of bursts occurred above the average MAP in older adults (P < 0.001), and a larger proportion of these bursts were associated with depressor responses (P = 0.005). Nonetheless, assessment of bursts above the average MAP associated with pressor responses revealed similar age-associated reductions in transduction (younger, Δ2.6 ± 1.6 vs. older, Δ1.7 ± 0.8 mmHg; P = 0.016). These findings indicate an age-related increase in burst occurrence above the average resting MAP, which alone does not explain blunted transduction, thereby supporting the physiological underpinnings of age-related decrements in sympathetic transduction to blood pressure.NEW & NOTEWORTHY The current study demonstrated that aging is associated with a greater prevalence of sympathetic bursts occurring above the average blood pressure, which offers both methodologically and physiologically relevant information regarding aging and sympathetic control of blood pressure. These data support age-related reductions in sympathetic transduction via a reduced pressor response to sympathetic bursts irrespective of the prevailing absolute blood pressure value, along with increases in sympathetic outflow necessary to maintain blood pressure.

Age differences in inhibitory and working memory functioning: limited evidence of system interactions

ABSTRACT Debate persists regarding the nature of age-related deficits in inhibition, and whether inhibitory functioning depends on working memory systems. The current research aimed to measure age-related differences in inhibition and working memory, characterize the relationship between inhibitory functions and working memory performance, and determine how these relationships are affected by age. Toward these ends, we measured performance on a range of established paradigms in 60 young adults (18–30 years) and 60 older adults (60–88 years). Our findings support age-related increases in reflexive inhibition (based on the fixation offset effect and inhibition of return) and age-related decrements in volitional inhibition (based on several paradigms: antisaccade, Stroop, flanker, and Simon). This evidence of stronger reflexive inhibition combined with weaker volitional inhibition suggests that age-related deterioration of cortical structures may allow subcortical structures to operate less controlled. Regarding working memory, older adults had lower backward digit scores and lower forward and backward spatial scores. However, of the 32 analyses (16 in each age group) that tested for dependence of inhibitory functioning on working memory functioning, only one (in young adults) indicated that inhibition performance significantly depended on working memory performance. These results indicate that inhibition and working memory function largely independently in both age groups, and age-related working memory difficulties cannot account for age-related declines in inhibitory control.

Cognitive challenge as a probe to expose sex- and age-related differences during static contractions.

Despite activities of daily living being frequently performed simultaneously with a cognitive task, motor function is often investigated in isolation, which can hinder the applicability of findings. This brief review presents evidence that 1) performing a cognitive challenge simultaneously with a motor task can negatively impact force steadiness and fatigability of limb muscles during a static contraction, 2) the negative impact on old adults (>65years old), particularly older women is greater than young when a cognitive challenge is simultaneously performed with a static motor task, 3) age-related mechanisms potentially explain impairments in motor performance in the presence of a cognitive challenge, and 4) the mechanisms for the age-related decrements in motor performance can be distinct between men and women. These observations are highly relevant to the older adults, given the increased risk of accidents and injury when a motor task is performed with a high cognitive-demand task, especially in light of the expanding reliance on an aging workforce.

LOSS OF ECM SYNTHESIZING TENOCYTES PROMOTES TENDON DEGENERATION WHILE INFLAMMATORY SKEWING IMPAIRS AGED TENDON HEALING

Depletion of Scleraxis-lineage (ScxLin) cells in adult tendon recapitulates age-related decrements in cell density, ECM organization and composition. However, depletion of ScxLin cells improves tendon healing, relative to age-matched wildtype mice, while aging impairs healing. Therefore, we examined whether ScxLin depletion and aging result in comparable shifts in the tendon cell environment and defined the intrinsic programmatic shifts that occur with natural aging, to define the key regulators of age-related healing deficits.ScxLin cells were depleted in 3M-old Scx-Cre+; Rosa-DTRF/+ mice via diphtheria toxin injections into the hindpaw. Rosa-DTRF/+ mice were used as wildtype (WT) controls. Tendons were harvested from 6M-old ScxLin depleted and WT mice, and 21-month-old (21M) C57Bl/6 mice (aged). FDL tendons (n=6) were harvested for single-cell RNAseq, pooled, collagenase digested, and sorted for single cell capture. Data was processed using Cell Ranger and then aligned to the annotated mouse genome (mm10). Filtering, unsupervised cell clustering, and differential gene expression (DEG) analysis were performed using Seurat.Following integration and sub-clustering of the tenocyte populations, five distinct subpopulations were observed. In both ScxLin depletion and aging, ‘ECM synthesizers’ and ‘ECM organizers’ populations were lost, consistent with disruptions in tissue homeostasis and altered ECM composition. However, in ScxLin depleted mice retention of a ‘specialized ECM remodeler’ population was observed, while aging tendon cells demonstrated inflammatory skewing with retention of a ‘pro-inflammatory tenocyte population’. In addition, enrichment of genes associated with protein misfolding clearance were observed in aged tenocytes. Finally, a similar inflammatory skewing was observed in aged tendon-resident macrophages, with this skewing not observed in ScxLin depleted tendons.These data suggest that loss of ‘ECM synthesizer’ populations underpins disruptions in tendon homeostasis. However, retention of ‘specialized remodelers’ promotes enhanced healing (ScxLin depletion), while inflammatory skewing may drive the impaired healing response in aged tendons.

Differential associations of mentally-active and passive sedentary behaviours and physical activity with putative cognitive decline in healthy individuals and those with bipolar disorder: Findings from the UK Biobank cohort

ObjectivePhysical activity confers protection against age-related cognitive dysfunction, but less is known about whether cognition is impacted by sedentary behaviour, specifically its mentally-active and passive forms. Both physical inactivity and sedentary behaviour are highly prevalent in bipolar disorder (BD), yet if and how they relate to the disorder's cognitive symptoms remains unclear. In this study, we explored whether individual variation in physical activity and sedentary behaviour was directly associated with cognition and/or moderated the extent of decrements in cognitive performance occurring as a function of age in people with BD versus psychiatrically-healthy controls. MethodsRelevant UK Biobank data were available for 1074 BD patients and 59,653 psychiatrically-healthy controls, aged 40–70. Age, mentally-active (computer use) and passive sedentary behaviour (TV viewing), physical activity, diagnosis, and their interactions were regressed on a global cognitive score. ResultsCognition was inversely associated with physical activity (β = −0.003, CI: −0.003, −0.003) and mentally-passive sedentary behaviour (β = −0.03, CI: −0.04, −0.02) and positively associated with mentally-active sedentary behaviour (β = 0.13, CI: 0.12, 0.15). The latter association was stronger in the BD group. Mentally-active sedentary behaviour moderated the age-cognition association in both BD patients and controls (β = 0.01, CI: 0.008, 0.01), such that age-related decrements in cognition were more apparent in those who engaged in less mentally-active sedentary behaviours compared to those who engaged in more. ConclusionsMentally-active sedentary behaviour may not only attenuate age-related cognitive dysfunction, but may be important for cognition irrespective of age, particularly in those with BD. These findings support the notion that intellectual stimulation is a protective factor conferring cognitive benefits, even in the context of a sedentary lifestyle.

Neutrophil-to-Lymphocyte Ratio Amplifies the Effects of Aging on Decrements in Grip Strength and Its Functional Neural Underpinnings.

The neutrophil-to-lymphocyte ratio (NLR) is a trans-prognostic biomarker of physiologic stress and inflammation linked to muscle weakness in older adults. Generation of grip force coincides with sustained activity in the primary sensorimotor cortex (SM1). The current study investigates whether whole-brain functional connectivity, that is, degree centrality (CD) of SM1 relates to grip strength and whether both functional measures are predicted by advancing age as a function of the NLR. Astructural regression model investigated the main and interactive effects of age and NLR on grip strength and CD of SM1 in 589 adults aged 21-85years (M=45.87, SD=18.06). The model including the entire sample had a good fit (χ 2(4)=1.63, p=.804). In individuals aged 50years and older, age predicted lower grip strength and SM1 CD as a function of increasing NLR. In a model stratified by sex, the effect of age, NLR, and their interaction on grip strength are significant for older men but not older women. Analyses support CD of SM1 at rest as a neural biomarker of grip strength. Grip and its neural underpinnings decrease with advancing age and increasing NLR in mid to late life. Age-related decrements in grip strength and functional connectivity of brain regions involved in the generation of dynamic grip appear to be accelerated as a function of systemic physiological stress and inflammation, particularly in older men.

Sex Differences in the Speed-Duration Relationship of Elite Runners across the Lifespan.

To determine if the speed-duration relationship is altered with age and sex of elite Master's runners. The world's top 10 performances for men and women in three events (800, 1500, and 5000 m) across six age groups (18-34 yr, 40-49 yr, 50-59 yr, 60-69 yr, 70-79 yr, and 80-89 yr) were analyzed from public data to establish theoretical models of the speed-duration relationship. Critical speed (CS) and the curvature constant ( D ') were estimated by fitting the average speeds and performance times with a two-parameter hyperbolic model. Critical speed expressed relative to the 18- to 34-yr-olds, declined with age (92.2% [40-49] to 55.2% [80-89]; P < 0.001), and absolute CS was higher in men than women within each age group ( P < 0.001). The percent difference in CS between the men and women progressively increased across age groups (10.8% [18-34] to 15.5% [80-89]). D ' was lower in women than men in the 60-69 yr, 70-79 yr, and 80-89 yr age groups ( P < 0.001), but did not differ in the 18-34 yr, 40-49 yr, or 50-59 yr age groups. Critical speed progressively decreased with age, likely due to age-related decrements in several physiological systems that cause reduced aerobic capacity. The mechanism for the larger sex difference in CS in the older age groups is unknown but may indicate physiological differences that occur with aging and/or historical sociological factors that have reduced participation opportunities of older female runners resulting in a more limited talent pool.

Abstract 13559: Altered Nucleotide Biosynthesis is a Prominent Metabolic Feature of Cardiac and Liver Aging

Introduction: The heart is particularly vulnerable to age-related dysfunction, with left ventricular hypertrophy and diastolic dysfunction developing in late life. In this study, we used deep network tracing to elucidate the effects of aging on glucose metabolism in the heart and peripheral tissues of a mouse model of late-life cardiac dysfunction. Hypothesis: Aging processes in the heart are mediated through altered nucleotide metabolism. Methods: Young (12–16 wk, n =6) and aged (80–84 wk, n =6) male C57BL/6J mice were subjected to treadmill exercise capacity tests and echocardiographic measurements. To delineate the effects of age on in vivo glucose metabolism, we delivered 13 C 6 -glucose to mice via a liquid diet and analyzed 13 C enrichment and the relative abundance of metabolites in the heart, liver, and skeletal muscle by ion exchange chromatography-mass spectrometry. Results: Compared with young mice, aged mice had lower exercise capacity (257.3 vs. 394.2 meters distance, p =0.0002 and 0.9 vs. 1.4 kg/m work, p =0.07), which was associated with a 1.3–fold increase in left ventricular mass ( p =0.0006) and longer isovolumetric relaxation time (IVRT: 12.3 vs. 14.1 ms, p =0.03). Although no significant differences in 13 C enrichment were found for metabolites in the glycolysis and tricarboxylic acid cycle pathways, we found 1.2- to 1.5-fold difference in 13 C enrichment ( p &lt;0.05) in purine (AMP, ADP, ATP and GMP, GDP, GTP) and pyrimidine (UMP, UDP, UTP, uridine, orotidine) metabolites. Additionally, aged hearts had 2.4-fold higher levels of the pyrimidine precursor N-carbamoyl L-aspartate. Similar changes were detected in the pyrimidine metabolite pool in aged liver, but not skeletal muscle. Conclusions: These data indicate that altered nucleotide biosynthesis is a prominent metabolic feature of cardiac and liver aging and could provide novel insights into age-related decrements in cardiovascular health.

Phytochemical Combination Is More Effective than Individual Components in Reducing Stress Signaling in Rat Hippocampal Neurons and Microglia In Vitro.

Age-related decrements in the central nervous system (CNS) are thought to result from: (1) increased susceptibility to and accumulating effects of free radicals and inflammation; and (2) dysregulation in Ca2+ homeostasis, which affects numerous signaling pathways. Certain bioactive phytochemicals exhibit potent anti-inflammatory activities which may mitigate these age-related CNS decrements. This study investigated the individual and combination effects of green tea catechin (epigallocatechin gallate, EGCG), curcumin from turmeric, and broccoli sprouts which contain the isothiocyanate sulforaphane on inflammation and dysregulation in Ca2+ homeostasis to determine if the individual compounds were working synergistically and/or through independent mechanisms. Rat hippocampal neurons or highly aggressive proliferating immortalized (HAPI) microglial cells were pre-treated for a week with either the individual components or all in combination before inducing Ca2+ buffering deficits with dopamine (DA, 0.1 µM for 2 h) or inflammation using lipopolysaccharide (LPS, 100 ng/mL for 18 h), respectively. The EGCG (3 µM) and combination protected against DA-induced deficits in Ca2+ buffering (both % of cells that recovered and recovery time, p < 0.05). Additionally, the EGCG and combination reduced stress-mediated inflammation in HAPI rat microglial cells by attenuating LPS-induced nitrite release, inducible nitrous oxide synthase (iNOS) expression, and tumor necrosis factor-alpha (TNF-α) release (p < 0.05), but not cyclooxygenase-2 (COX-2) expression. Overall, broccoli sprouts (2 µM) and curcumin (1 µM) were not as effective as the EGCG or combination. Further research is needed to determine if dietary intervention with a variety of foods containing compounds such as those found in green tea, turmeric, or broccoli sprouts can play a role in reducing age-related CNS inflammation, microglial activation, and downstream signaling pathways that can lead to neuronal dysfunction.

Instructing Use of an Effective Strategy Improves Recognition Memory in Healthy Adults.

Age-related memory decrements correlate with metacognitive declines, including knowledge and deployment of effective mnemonic encoding strategies. However, whether imparting such strategy suffices for mitigating memory differences is unclear. In a longitudinal study of 276 healthy adults aged 18-79 years, we tested associative and working memory, and assessed beliefs regarding mnemonic strategies. Testing was repeated every 2 years, 5 times. Starting with the third occasion, we instructed participants to use an effective mnemonic strategy (sentence generation). Using continuous-time dynamic modeling, we assessed changes in the item and associative recognition, intervention effects, and their relations with age, sex, meta-memory beliefs, working memory, and metabolic health. Younger age, better working memory, and stronger belief in effective mnemonic strategies predicted better recognition, whereas instructional intervention attenuated associative memory deficits, with some persistence over time. The present findings show merely imparting effective strategies holds promise for mitigating age-related associative memory deficits.

The effect of the inclusion of trunk-strengthening exercises to a multimodal exercise program on physical activity levels and psychological functioning in older adults: secondary data analysis of a randomized controlled trial

BackgroundEngaging in multimodal exercise program helps mitigate age-related decrements by improving muscle size, muscle strength, balance, and physical function. The addition of trunk-strengthening within the exercise program has been shown to significantly improve physical functioning outcomes. Whether these improvements result in improved psychological outcomes associated with increased physical activity levels requires further investigation. We sought to explore whether the inclusion of trunk-strengthening exercises to a multimodal exercise program improves objectively measured physical activity levels and self-reported psychological functioning in older adults.MethodWe conducted a secondary analysis within a single-blinded parallel-group randomized controlled trial. Sixty-four healthy older (≥ 60 years) adults were randomly allocated to a 12-week walking and balance exercise program with (n = 32) or without (n = 32) inclusion of trunk strengthening exercises. Each program involved 12 weeks of exercise training, followed by a 6-week walking-only program (identified as detraining). Primary outcome measures for this secondary analysis were physical activity (accelerometry), perceived fear-of-falling, and symptoms of anxiety and depression.ResultsFollowing the 12-week exercise program, no significant between-group differences were observed for physical activity, sedentary behaviour, fear-of-falling, or symptoms of anxiety or depression. Significant within-group improvements (adjusted mean difference [95%CI]; percentage) were observed in moderate-intensity physical activity (6.29 [1.58, 11.00] min/day; + 26.3%) and total number of steps per min/day (0.81 [0.29 to 1.33] numbers or + 16.3%) in trunk-strengthening exercise group by week 12. With respect to within-group changes, participants in the walking-balance exercise group increased their moderate-to-vigorous physical activity (MVPA) (4.81 [0.06 to 9.56] min/day; + 23.5%) and reported reduction in symptoms of depression (-0.26 [-0.49 to -0.04] points or -49%) after 12 weeks of the exercise program. The exercise-induced increases in physical activity levels in the trunk-strengthening exercise group were abolished 6-weeks post-program completion. While improvements in physical activity levels were sustained in the walking-balance exercise group after detraining phase (walking only).ConclusionsThe inclusion of trunk strengthening to a walking-balance exercise program did not lead to statistically significant between-group improvements in physical activity levels or psychological outcomes in this cohort following completion of the 12-week exercise program.Trial registrationAustralian and New Zealand Clinical Trials Registry (ACTRN12613001176752), registered on 28/10/2013.

Alterations in Retinal Signaling Across Age and Sex in 3xTg Alzheimer's Disease Mice.

Background:Visual disturbances often precede cognitive dysfunction in patients with Alzheimer’s disease (AD) and may coincide with early accumulation of amyloid-β (Aβ) protein in the retina. These findings have inspired critical research on in vivo ophthalmic Aβ imaging for disease biomarker detection but have not fully answered mechanistic questions on how retinal pathology affects visual signaling between the eye and brain.Objective:The goal of this study was to provide a functional and structural assessment of eye-brain communication between retinal ganglion cells (RGCs) and their primary projection target, the superior colliculus, in female and male 3xTg-AD mice across disease stages.Methods:Retinal electrophysiology, axonal transport, and immunofluorescence were used to determine RGC projection integrity, and retinal and collicular Aβ levels were assessed with advanced protein quantitation techniques.Results:3xTg mice exhibited nuanced deficits in RGC electrical signaling, axonal transport, and synaptic integrity that exceeded normal age-related decrements in RGC function in age- and sex-matched healthy control mice. These deficits presented in sex-specific patterns among 3xTg mice, differing in the timing and severity of changes.Conclusion:These data support the premise that retinal Aβ is not just a benign biomarker in the eye, but may contribute to subtle, nuanced visual processing deficits. Such disruptions might enhance the biomarker potential of ocular amyloid and differentiate patients with incipient AD from patients experiencing normal age-related decrements in visual function.

Interleukin-6 potentiates endurance training adaptation and improves functional capacity in old mice.

BackgroundInterventions to preserve functional capacities at advanced age are becoming increasingly important. So far, exercise provides the only means to counteract age‐related decrements in physical performance and muscle function. Unfortunately, the effectiveness of exercise interventions in elderly populations is hampered by reduced acceptance and compliance as well as disuse complications. We therefore studied whether application of interleukin‐6 (IL‐6), a pleiotropic myokine that is induced by skeletal muscle activity and exerts broad systemic effects in response to exercise, affects physical performance and muscle function alone or in combination with training in aged mice.MethodsSedentary old male mice (Sed+Saline, n = 15) were compared with animals that received recombinant IL‐6 (rIL‐6) in an exercise‐mimicking pulsatile manner (Sed+IL‐6, n = 16), were trained with a moderate‐intensity, low‐volume endurance exercise regimen (Ex+Saline, n = 13), or were exposed to a combination of these two interventions (Ex+IL‐6, n = 16) for 12 weeks. Before and at the end of the intervention, mice underwent a battery of tests to quantify endurance performance, muscle contractility in situ, motor coordination, and gait and metabolic parameters.ResultsMice exposed to enhanced levels of IL‐6 during endurance exercise bouts showed superior improvements in endurance performance (33% more work and 12% greater peak power compared with baseline), fatigue resistance in situ (P = 0.0014 vs. Sed+Saline; P = 0.0199 vs. Sed+IL‐6; and P = 0.0342 vs. Ex+Saline), motor coordination (rotarod performance, P = 0.0428), and gait (gait speed, P = 0.0053) following training. Pulsatile rIL‐6 treatment in sedentary mice had only marginal effects on glucose tolerance and some gait parameters. No increase in adverse events or mortality related to rIL‐6 treatment was observed.ConclusionsAdministration of rIL‐6 paired with treadmill running bouts potentiates the adaptive response to a moderate‐intensity low‐volume endurance exercise regimen in old mice, while being safe and well tolerated.

Educational Mobility and Age-Related Decrements in Kidney Function Across Adulthood Among Black and White Adults

This paper examines the association between educational mobility and age-related decrements in kidney function. Data from the main survey and the Biomarker Project of the Midlife in the United States (MIDUS) Wave 2 and Refresher samples were combined, resulting in 1,861 adults (54.5% female; age 25-84, Mage=53.37) who self-identified as non-Hispanic Black (n=326) and non-Hispanic white (n=1,535). The estimated glomerular filtration rate (eGFR) was based on serum creatinine, calculated using the CKD-EPI formula. Intergenerational educational mobility was based on the comparison between parental education (no high school/HS degree versus HS degree or higher) and participant’s education level (HS degree or lower versus some college versus bachelor’s degree or higher). Results from regression analysis indicated that Black participants in the moderate upward mobility group (parental education = no HS degree, participant’s education = some college) showed significantly steeper age-related decrements in eGFR across adulthood compared to Black adults with higher stable high status (parental education = HS degree or higher, participant’s education = bachelor’s degree or higher), B=-0.70, SE=0.26, p=.008, or white adults with higher stable high status, B= 0.58, SE=0.29, p=.044. A steeper age-related decrement in eGFR is known as a reliable risk factor for chronic kidney disease and cardiovascular disease. These findings support the notion of skin-deep resilience among Black adults who experience upward socioeconomic mobility. We explored multiple psychosocial factors that may explain these findings, including lifetime and daily discrimination, social status and financial strains, and perceived stress and depressive symptoms.