Frontiers in Aging

Background/Objective: Common measures of physical activity (PA) based on duration and intensity do not fully capture its complexity. Adding additional PA components of muscle strength, mechanical strain, and turning actions, can provide a more complete view of activity behavior. Furthermore, PA behaviors differ between men and women. Therefore, the goal of this study is to identify and cluster similar long-term PA patterns over time for each PA component, examined separately for men and women. Methods: We used data from 4963 participants (52% women; mean age 66 years, SD = 8.6) of the Longitudinal Aging Study Amsterdam (1992 to 2019). PA component scores were assigned to self-reported activities, and Sequence Analysis with Optimal Matching was used to identify and cluster similar activity patterns over a period of 10 years, separately for each component and stratified by sex. Results: PA components varied by sex and displayed a unique mix of trajectories, including predominately low, medium, or high activity, increasing or decreasing patterns, and trajectories characterized by early or late mortality. Importantly, trajectories remained independent, indicating that changes in one PA component were not linked to changes in others. Conclusion: Older men and women follow distinct and independent long term PA trajectories across components, underscoring that PA behaviour cannot be described by a single dimension. Significance/Implications: The observed independence and heterogeneity of trajectories suggest that muscle strength, mechanical strain, and turning actions capture meaningful and distinct aspects of PA that are not reflected by traditional measures alone. Future PA-strategies could incorporate these dimensions and acknowledge sex-specific patterns to better reflect natural movement. The independence of components suggests that future interventions should target multiple dimensions, as changes in one component may not translate to others. Such an approach may support more tailored and sustainable PA interventions in later life.

Aging is associated with a progressive loss of skeletal muscle function, known as sarcopenia; however, the molecular mechanisms coordinating cellular stress responses and structural adaptations permissive of sarcopenia remain incompletely understood. In our previous studies, we found aging differentially impacted mitochondrial networks by muscle, suggesting unique stress thresholds and response activation. Here, we investigate the role of activating transcription factor 4 (ATF4), a master regulator of the integrated stress response (ISR), in aged quadriceps muscle using complementary patient and aging mouse models. Older adults exhibited a marked decrease in aerobic capacity, muscle strength, and endurance when compared with young participants. These results paralleled findings in aged mice, with significant loss of muscle mass across multiple hindlimb muscles. Ultrastructural analysis revealed substantial age-related changes in mitochondrial morphology, including increased volume, surface area, and branching index, as well as a shift toward larger, more complex mitochondria. Our data indicate that ATF4 binds directly to the promoter region of the gene encoding TFAM, suggesting a transcriptional regulatory relationship to support DNA stability. These structural and transcriptional changes likely impair oxidative capacity and drive a feed-forward cycle of mitochondrial dysfunction and ISR activation. Our findings indicate that ATF4 coordinates transcriptomic and structural adaptations in aging muscle, identifying the ISR pathway as a potential therapeutic target for preserving muscle function in older adults.

AbstractAs organisms age, mitochondrial metabolic activity declines, and disrupted gene expression regulation mediated by histone acetylation induces the emergence of senescent physiological phenotypes in tissues. In this study, we found that periodic exposure to red light significantly increased histone H3 Lys9 acetylation (H3K9ac) levels in the tissues and organs of aged mice. Following red light exposure, silent information regulation factor 4 (SIRT4) protein levels in keratinocytes were notably reduced, whereas glycolysis, fatty acid metabolism, and the tricarboxylic acid (TCA) cycle were significantly activated in keratinocytes. The reduction in mitochondrial SIRT4 levels enhances the acetylation of mitochondrial metabolic proteins, particularly malonyl-CoA decarboxylase (MCD), a potent inhibitor of the key rate-limiting enzyme carnitine palmitoyltransferase 1A (CPT1A) in fatty acid oxidation. This process promotes mitochondrial fatty acid oxidation and TCA cycle. Additionally, the decrease in SIRT4 activates SIRT1 through feedback mechanisms, thereby alleviating its inhibition on PPAR- in senescent keratinocytes and comprehensively activating the expression of genes related to lipid metabolism. This lipid metabolism activation ultimately facilitates the accumulation of acetyl-CoA within keratinocytes, increases H3K9ac levels, and reshapes the expression patterns of senescence-related genes. Eventually, cellular aging is effectively mitigated by the synergistic regulation of metabolism, inflammation, and gene expression. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=157 SRC="FIGDIR/small/717004v1_ufig1.gif" ALT="Figure 1"> View larger version (76K): org.highwire.dtl.DTLVardef@a3387dorg.highwire.dtl.DTLVardef@1d1b083org.highwire.dtl.DTLVardef@19ba6f0org.highwire.dtl.DTLVardef@1ecf20e_HPS_FORMAT_FIGEXP M_FIG Mechanism of anti-aging action of red light: Red light can reduce SIRT4 signalling in keratinocytes, thereby reactivating lipid metabolism and increasing levels of acetyl-CoA. This promotes histone acetylation, which in turn reverses the expression of age-related inflammatory factors and genes. C_FIG

{Delta}133p53 is a naturally occurring isoform of the human p53 protein that inhibits p53-mediated cellular senescence. We recently reported that transgenic expression of this senescence-inhibitory p53 isoform counteracts aging-associated pathological changes and extends lifespan in progeria model mice (heterozygous LmnaG609G/+). The anti-aging effect of {Delta}133p53 was attributed in part to reduced levels of the proinflammatory cytokine IL-6. To comprehensively profile {Delta}133p53-induced changes in cytokines and chemokines, we in this study performed a Luminex-based multiplex quantitative assay of mouse sera collected from transgenic {Delta}133p53-expressing LmnaG609G/+ mice and non-expressing controls. This assay not only confirmed the {Delta}133p53-mediated repression of IL-6 but also showed that {Delta}133p53 reduced the levels of CXCL1 (also known as KC), IL-1, and CXCL10 (also known as IP-10). Among these factors, we further characterized CXCL10, which has not previously been associated with progeria in mice or humans. Consistent with reduced serum CXCL10 levels, both young (15-week-old) and old (10-month-old) {Delta}133p53-expressing LmnaG609G/+ mice showed reduced Cxcl10 expression, compared with age-matched non-expressing controls, in the liver, spleen, and brain, major organs known to produce CXCL10. In naturally aged wild-type mice (2-year-old), Cxcl10 expression was also significantly repressed by transgenic {Delta}133p53 in the spleen and brain. Analysis of gene expression datasets from human tissues demonstrated an inverse association between CXCL10 and {Delta}133p53 levels, suggesting physiological relevance to human aging. This study defines CXCL10 as a proinflammatory chemokine elevated in both accelerated and natural aging and as a potential target of the anti-inflammatory activity of {Delta}133p53.

Time-restricted feeding (TRF) aligned with an organisms circadian rhythm has been shown to improve health, but its long-term effects on healthspan and lifespan in mammals, especially under normal dietary conditions, remain unclear. Here, we examined the impact of 12-hour (h) and 8h nightly TRF windows in male and female mice fed regular chow. TRF improved multiple health measures, including behavioral rhythmicity, body weight and composition, frailty, and disease onset. These effects were most pronounced in the 8h-TRF group, which exhibited voluntary caloric restriction in addition to time restriction. A composite Healthspan Index revealed that TRF extended healthspan in both sexes, though the benefits were more prolonged in females relative to their total lifespan. Median lifespan was significantly extended in males under 8h-TRF by 12%, whereas females showed no significant lifespan extension, highlighting sex-specific responses to TRF.

Dietary protein intake mediates healthy aging in diverse species, with consumption of a low protein (LP) diet improving metabolic health in both humans and mice. In mice, the benefits of LP diets are sex-specific, with males exhibiting a stronger response to a LP diet than females. The reason for this sexually dimorphic response is unknown, but we hypothesized that sex hormones might be responsible for this difference. Here, we tested the role of sex hormones in the response to a LP diet by feeding intact and gonadectomized mice of both sexes either a Control (21% of calorie from protein) or LP (7% of calories from protein) diet, and assessing the effects on weight, body composition, glycemic control, and energy balance over the course of three months, followed by molecular and histological analysis of tissues from each group. We confirm that males show a stronger metabolic response to an LP diet than females, but that ovariectomy sensitizes female mice to the metabolic effects of an LP diet, making them respond more similarly to males; conversely, castration does not substantially impact the response of males to an LP diet. Molecularly, we find that gonadectomy and sex are important interactors that mediate the response of mechanistic target of rapamycin (mTOR) signaling, lipid homeostasis, and thermogenesis to an LP diet. Together, this data shows that the resistance of female mice to an LP diet is mediated by ovarian hormones and suggests the possibility that older female humans might receive enhanced benefits from LP diet feeding.

Frailty is an age-related syndrome characterized by biological dysfunction and reduced physiological reserve in response to stressors. Its prevalence is increasing with population aging, resulting in a substantial health burden due to adverse outcomes on health, such as cardiovascular disease and mortality. Ultra-processed foods (UPFs), defined as industrial formulations made primarily from processed ingredients, have received increasing attention due to their potential role in the development and progression of frailty. This systematic review and meta-analysis examined the association between ultra-processed food intake and the risk of frailty in older adults. This study systematically searched for all relevant studies published up to January 2026. Ten observational studies involving 105327 participants, comprising 6 prospective and 4 cross-sectional studies, were included in the systematic review, of which 6 were eligible for meta-analysis. Random-effects models were employed to estimate pooled effect sizes and 95% confidence intervals (95% CIs). Meta-analysis showed that higher consumption of UPFs was significantly associated with an increased risk of frailty (pooled OR = 1.43, 95% CI = [1.02-2.005], p = 0.041). Narrative synthesis further supported a positive association between UPF intake and frailty or related outcomes. Our findings suggest that a higher consumption of ultra-processed foods may contribute to frailty risk, potentially through inflammatory pathways. However, given the high heterogeneity, results should be interpreted with caution. Overall, our findings suggest that reducing UPF consumption may be a promising target for public health strategies to prevent frailty in ageing populations.

We evaluated 2024/25 KP.2 vaccine effectiveness (VE) against COVID-19 hospitalization among adults >60 years old eligible for publicly-funded vaccination during fall and/or spring campaigns in the province of Quebec, Canada. We included Quebec residents tested for COVID-19-compatible symptoms in an acute-care hospital between October 13, 2024 (epi-week 2024-42) and August 23, 2025 (2025-34), linking vaccine, hospital, chronic diseases and laboratory administrative records to assess VE through test-negative design. We compared the odds of being COVID-19 test-positive versus test-negative among vaccinated versus non-vaccinated participants, adjusting for sex, age, comorbidities, place of residence, and epidemiological week. Overall, 49,949 (43%) participants were vaccinated. Over an analysis period spanning up to ten months, including median time since vaccination of 16 weeks (interquartile range 9-24 weeks), VE was 34% overall, declining from 43% <8 weeks to negligible by the 32nd week post-vaccination. Findings confirm meaningful but short-lived COVID-19 vaccine protection against hospitalization in older adults.

Tauopathies, including Alzheimers disease, are age-related neurodegenerative disorders characterized by abnormal phosphorylation and buildup of microtubule-associated protein tau. Gene expression dysregulation is a key molecular feature of tauopathies, but how aging and disease interact to disrupt crucial transcriptional regulators and pathways remains largely unknown. Here, we examined how pathological tau affects gene expression programs in age-related neurodegenerative disease using a well-established Drosophila melanogaster tauopathy model with neuronal expression of the toxic human tauR406W. Transcriptomic analysis of tau-expressing fly heads showed a preferential downregulation of long neuronal genes with long introns. Notably, we found that these downregulated genes in the tauopathy model are marked by increased accumulation of initiating RNA polymerase II (RNAP II) near the transcription start site and reduced elongating RNAP II within gene bodies, indicating a problem with the transition from initiation to elongation. By calculating an RNAP II Pause Index (PI) for each gene, we identified a strong link between promoter-proximal RNAP II stalling, gene expression deficits, and gene length in the tauopathy model. Overall, we have uncovered the genomic and transcriptomic features of tau-dependent downregulated genes and identified increased RNAP II promoter-proximal stalling as a significant mechanism of transcription stress in tauopathy.

Walking impairments in Parkinsons disease (PD), including reduced speed, cadence, and stride length, and increased variability, impair mobility and raise fall risk. Conventional treatments may fail to address these deficits, underscoring the need for complementary non-invasive alternatives. This study examined whether combining rhythmic auditory cueing with transcranial direct current stimulation (tDCS) over the supplementary motor area (SMA), a critical region for internally-generated movement, would enhance gait performance in PD. Thirty-three participants with PD and thirty-two healthy controls completed two sessions (anodal vs. sham tDCS) with gait assessed during stimulation, immediately after stimulation, and 15 minutes after stimulation under two auditory conditions: walking in silence and walking to music paced 10% faster than baseline cadence. Spatiotemporal, variability, and stability gait parameters were analyzed using linear mixed-effects models. Rhythmic auditory cueing significantly increased cadence and speed during, immediately after, and especially 15 minutes after stimulation, suggesting sustained effects of rhythmic entrainment. Anodal tDCS produced faster cadence, as well as lower stride time variability and stride width, particularly in individuals with PD. Although both music and anodal tDCS affected gait, no interaction was observed, indicating independent effects. Individuals with PD had greater gait variability overall, and adjusted temporal gait parameters less to music than healthy controls did. Anodal stimulation reduced walking variability in PD, reducing the group differences observed under sham conditions. These findings suggest that rhythmic cueing and SMA stimulation target complementary mechanisms, highlighting the promise of combined tDCS-music interventions for gait rehabilitation in PD.

Background: The 2025/2026 COVID-19 vaccine season introduced updated formulations targeting the LP.8.1 lineage. This study assessed the absolute vaccine effectiveness (aVE) of mRNA-1283 and BNT162b2 on COVID-19 outcomes in adults aged [&ge;]65 years. Methods: Background: The 2025/2026 COVID-19 vaccine season introduced updated formulations targeting the LP.8.1 lineage. This study assessed the absolute vaccine effectiveness (aVE) of mRNA-1283 and BNT162b2 on COVID-19 outcomes in adults aged [&ge;]65 years. Methods: This retrospective study used linked electronic health record and administrative claims data through Jan 31, 2026. Adults [&ge;]65 years who received the mRNA-1283 or BNT162b2 2025/2026 COVID-19 vaccine were matched to unvaccinated individuals. Inverse probability of treatment weighting was applied to matched cohorts of each vaccine to balance covariates. Each vaccine was evaluated independently against its own unvaccinated comparator group. aVE against COVID-19 related hospitalization and medically-attended COVID-19 was estimated using Cox proportional hazards models; aVE = 100 x (1 - hazard ratio [HR]). Results: We identified 233,072 mRNA-1283 recipients and 422,610 BNT162b2 recipients [&ge;]65 years. The aVE (95% confidence interval) of mRNA-1283 against COVID-19 related hospitalization and medically-attended COVID-19 was 59.3% (39.0%, 72.9%) and 42.0% (35.0%, 48.3%) among adults [&ge;]65 years and 66.9% (45.9%, 79.8%) and 50.2% (42.1%, 57.2%) in [&ge;]75 years, respectively. The aVE of BNT162b2 against COVID-19 related hospitalization and medically-attended COVID-19 was 48.3% (32.4%, 60.5%) and 41.2% (36.2%, 45.8%) in [&ge;]65 years and 45.9% (26.0%, 60.4%) and 44.0% (37.8%, 49.6%) in [&ge;]75 years, respectively. Conclusions: This is the first real-world evidence showing that mRNA-1283 prevents COVID-19-related hospitalizations and medically attended events in vulnerable older adults at highest risk of severe disease. These findings support mRNA-1283 as an important public health tool for reducing the ongoing burden of COVID-19.Results: We identified 233,072 mRNA-1283 recipients and 422,610 BNT162b2 recipients [&ge;]65 years. The aVE (95% confidence interval) of mRNA-1283 against COVID-19 related hospitalization and medically-attended COVID-19 was 59.3% (39.0%, 72.9%) and 42.0% (35.0%, 48.3%) among adults [&ge;]65 years and 66.9% (45.9 %, 79.8%) and 50.2% (42.1%, 57.2%) in [&ge;]75 years, respectively. The aVE of BNT162b2 against COVID-19 related hospitalization and medically-attended COVID-19 was 48.3% (32.4%, 60.5%) and 41.2% (36.2%, 45.8%) in [&ge;]65 years and 45.9% (26.0%, 60.4%) and 44.0% (37.8%, 49.6%) in [&ge;]75 years, respectively. Conclusions: This is the first real-world evidence showing that mRNA-1283 prevents COVID-19-related hospitalizations and medically attended events in vulnerable older adults at highest risk of severe disease. These findings support mRNA-1283 as an important public health tool for reducing the ongoing burden of COVID-19.

IntroductionIndividuals with COPD can be classified according to their levels of physical activity (PA) and physical capacity (PC). The relationship between nutrition and body composition within these classifications remains unclear. ObjectivesTo compare the body composition and food intake of people with COPD and verify the associations. MethodsCross-sectional exploratory analysis study in which body composition and food intake were assessed in individuals with COPD. Classification was based on six-minute walk test (PC) and accelerometry(PA): Quadrant "can do, dont do" (I-preserved PC, low PA); quadrant "can do, do do" (II-preserved PC, preserved PA). Results72 individuals with COPD, 39 in quadrant I and 33 in quadrant II, with mean ages of (69 {+/-} 6) (67 {+/-} 7), respectively. Group I had a higher proportion of males, whereas group II had a higher proportion of females. A positive trend in skeletal muscle mass (p=0.011) (B= 2.883) and a negative trend in basal metabolic rate (p=0.010) (B=-0.092) for group I. ConclusionBrazilians with COPD classified in quadrants I and II showed similar results in terms of body composition and food intake. A positive trend in skeletal muscle mass was observed for the group I. These findings align with the pathophysiological model of COPD, in which the preservation of muscle mass and adequate protein intake support functional capacity and the maintenance of higher physical activity levels.

Chronic oxidative stress is a major contributor to neuronal aging. Due to the lack of homologous recombination (HR) DNA damage repair, high oxygen consumption in neurons causes DNA damage accumulation with age, resulting in a decline in neuronal function, senescence-like phenotypes and onset of neurodegenerative diseases. Here, we identify increased PTBP1 as a stress-inducible negative regulator of neuronal gene expression and senescence-protectant genes. Oxidative stress robustly increases PTBP1 expression in ShSY-5Y differentiated neurons and primary mouse cortical neurons, coinciding with the loss of neuronal genes, including neuronal PTBP2, and activation of stress-responsive genes. Knockdown of PTBP1 in fibroblasts reduces the expression of key senescence genes. Transcriptomic analyses revealed that PTBP1 overexpression results in coordinated shift in gene expression characterized by repression of neuronal commitment genes and activation of stress and senescence genes. Mechanistically, PTBP1 induction is regulated by stress induced CTCF binding at the PTBP1 promoter. Together, our findings suggest that alteration in levels of PTBP1 acts as a molecular switch between neuronal function and survival, providing insight into transcriptional adaptations associated with aging. SUMMARYO_LILoss of PTBP1 in fibroblasts acts as a senescence protective gene C_LIO_LIxidative stress induces expression of PTBP1, reducing neuronal function gene expression and activating stress and cell cycle genes C_LIO_LIEctopic PTBP1 expression reprograms neuronal transcription, down-regulating cell fate commitment genes and activating a cell senescence program C_LIO_LIxidative stress induces PTBP1 and suppresses neuronal specific PTBP2 expression in primary cortical neurons C_LI

ABSTRACT BACKGROUND: Recent studies consisting primarily of white participants have found lowered plasmalogen levels to be associated with lower cognitive function. We explore the association of blood plasmalogen levels with global cognition and brain imaging metrics in older African Americans. METHODS: Included in these cross-sectional analyses were participants in the Minority Aging Research Study (MARS) and the Rush Clinical Core without dementia, available serum lipid levels, and a concurrent cognitive function assessment. A plasmalogen biosynthesis value (PBV) was calculated for each participant utilizing five ratios of four key glycerophospholipids. A linear regression model of global cognition was constructed with PBV, adjusted for sex, age, education, total cholesterol, and body mass index. In participants with 3T MRI brain imaging, the association between PBV and white matter hyperintensities (WMH) was explored. RESULTS: Of the 298 participants, the mean age was 74.6 years, mean education was 15.6 years, and 84% were women. The median PBV was 0.42 (interquartile range: 0.22 to 1.14). A unit higher in PBV was suggestively associated with a 0.17 {beta}-unit higher cognitive z-score (SE =0.09, p = 0.06). In 254 participants with MRI data, an increase in log10 SD of PBV suggested the less white matter hyperintensities (estimate = -0.20, SE = 0.12, p = 0.08). DISCUSSION: In older African Americans, higher PBV was associated with higher level of global cognition, and potentially lower levels of brain white matter hyperintensities. Larger studies are needed in additional cohorts to determine if PBV is associated with annual rate of change in cognitive function.

Objective: To develop the first inventory to measure psychosocial concerns about use of the non-preferred hand, toward the long-term goal of identifying the casual factors of left-right hand choices ("hand usage"). Design: Cross-sectional Setting: Online question battery Participants: 181 healthy adults Interventions; Not applicable Main Outcome Measures: Self-reported concerns about emotional and physical consequences of using the non-preferred hand. Results: Emotional and physical consequences reflected internally consistent categories (Cronbach's > 0.9) that were moderately correlated with each other ({rho} = 0.783 p = 0.002). Concerns were activity-dependent in each category ({rho} < 1x10-100). Reliability analysis and principal components analysis were used to reduce the battery to the 51-item Changed Hand Usage Concerns inventory, which encompasses everyday tasks and concerns about physical and emotional consequences of using the non-preferred hand in those tasks. Conclusions: Concerns about emotional vs. physical consequences of non-preferred hand use reflect coherent and internally consistent categories The Changed Hand Usage Concerns inventory allows assessment of psychosocial concerns about usage of the non-preferred hand for future attempts to manipulate hand usage via rehabilitation in patients with unilateral or asymmetric impairment.

Documenting and understanding the welfare of aging animals are crucial for maintaining their well-being and making appropriate management decisions. This study details the behaviors of an extremely old rhesus macaque (ISK) in which senile plaques and phosphorylated tau deposition were observed in post-mortem pathological analyses of the brain. We report on the activity bsudgets, behavioral rhythms, gait, quality of life (QoL) scores, and anecdotal episodes of this individual. The average 24-hour activity budgets, analyzed from surveillance camera recordings, revealed that ISK spent most of her time inactive. ISK was sometimes active at night, though her behavior remained predominantly diurnal. Gait analysis suggested that her movement patterns changed between the first (December 2020) and the last (June 2021) assessment. QoL assessments, using a scoring sheet, indicated relatively good well-being until the later stage of her life. An anecdotal episode, along with the husbandry diary, suggested signs of cognitive decline. These results suggest possible signs of physical decline, and some behavioral changes that could be associated with cognitive decline in an extremely old rhesus macaque. However, we could not confirm cognitive dysfunction without further controlled cognitive testing. We hope that future studies will consider the behavioral symptoms observed in this study as monitoring items to better understand physical and cognitive decline, and possible relationships with QoL in primates.

Stem cell niches are dynamic microenvironments that regulate tissue homeostasis. Epidermal stem cells (EpiSC) preferentially localize to concave regions of epidermal rete ridges, which serve as primary niches for stem cell maintenance. EpiSC number and functional integrity decline during chronological aging. A defining feature of aged skin is epidermal atrophy, in which the prominent rete ridges present in young skin become flattened. Whether such topographical alterations influence EpiSC homeostasis and differentiation remains unclear. To address this, we generated anatomically accurate rete ridge structures using 3D bioprinting of collagen matrices as an ex vivo model and compared EpiSC cultured within concave topography to those maintained on a flat matrix resembling aged skin. Transcriptomic analysis revealed that concave niches promoted keratinocyte differentiation, marked by increased type I and II keratin gene expression and downregulation of cell cycle-associated genes. ATAC-seq identified topography-dependent chromatin accessibility changes enriched for transcription factors regulating epidermal differentiation, including upregulation of KLF4 and GRHL3 and downregulation of SOX9, HOXA1, and ETS1. Consistently, aged human skin showed reduced KLF4 and GRHL3 and increased SOX9 compared with young skin. Our findings demonstrate that concave niche topography imposes a spatially defined EpiSC microenvironment that promotes differentiation, alters cell cycle, and when perturbed, potentially contributes to the aging process. We conclude that spatial localization within rete ridge regions significantly affects epidermal progenitor stemness properties as fundamental differences in the physical microenvironment appear to influence cell fate decisions, thus, form shapes function of EpiSC.

Objectives: To determine the impact of discharge home on physical activity and sedentary behaviour following orthopaedic trauma. Design: Observational study. Setting: Acute hospital. Participants: Between October 2022 and January 2024, 31 adult orthopaedic trauma patients were recruited during hospital admission. Participants had either an isolated hip fracture or multi-trauma (i.e., a lower limb fracture, with an upper limb and/or spinal fracture). Interventions: Participants wore two activity monitors (activPAL3 and ActiGraphGT3x) during the final days of an acute hospital admission and the first five days at home. An interrupted time series analysis evaluated changes physical activity variables during the hospital to home transition. Participants were analysed individually using mixed-effects linear regression allowing the intercept to vary by participant. Main outcome measures: Primary outcome was daily steps; secondary outcomes included sedentary time and other activity measures. Results: Daily steps (mean +- SD) were higher at home (4552.4 +- 2639.5) compared to hospital (2597.8 +- 1450.8). Modelled results indicated a 27% increase in daily steps following hospital discharge (exp(beta946;): 1.27, 95% CI: 1.01,1.59, p=0.039) and a sustained improvement at home. No significant differences were observed between hip fracture and multi-trauma participants. Conclusion: Participants recovering from orthopaedic trauma showed a significant increase in daily step count upon discharge home from hospital, highlighting the positive impact of the home environment on activity levels. Further research is warranted to assess the effectiveness of interventions to improve activity levels in hospital (e.g., early intensive therapy) and at home (e.g., immediate home-based physiotherapy) in individuals following orthopaedic trauma.

Age-related macular degeneration is a common ocular disease that causes vision loss in the elderly, with a complex set of risk factors and proposed mechanisms of pathogenesis. A powerful method for investigating changes in disease is metabolomics, by which small molecules can be identified and quantified simultaneously. We report here the metabolic analysis of human RPE-choroid tissue in aging and macular degeneration (AMD), as well as comparisons of human macular and extramacular RPE-choroid and neural retina. Levels of 215 metabolites were determined in young donors, AMD donors (early/intermediate, geographic atrophy, and neovascularization) and age-matched controls. The largest number of metabolite differences were observed between young and healthy aged controls, as opposed to between aged controls and any stage of AMD. Two notable metabolites found to be increased in aging choroids are trimethylamine N-oxide and uric acid, both of which were significant after Bonferroni correction. A mouse endothelial cell line treated with a high concentration of uric acid exhibited reduced migration in a wound closure assay. This study provides initial insights into the metabolome of human choroids in varying states of age and macular degeneration, as well as functional implications of these changes in the aging choroid.

This study aimed to determine the impact of inborn metabolic fitness and early life exercise training on whole body and brown adipose tissue (BAT) energetics. We carried out comprehensive metabolic phenotyping on 4-week old rats bred for high (high-capacity runner, HCR) and low (low-capacity runner, LCR) running capacity following randomization to voluntary wheel running (VWR) or control (CRTL) for 6-weeks. High-resolution respirometry and untargeted proteomics were then employed to determine the impact of inborn fitness and early life exercise on BAT function. When accounting for differences in body mass, early life exercise (VWR) resulted in greater basal and total energy expenditure, irrespective of strain (P < 0.0001 for both). Both leak and uncoupling protein 1 (UCP1) dependent respiratory capacities in isolated BAT mitochondria were greater in rats randomized to VWR compared to CTRL in both HCR (P < 0.01) and LCR (P < 0.05) strains. Similarly, mitochondrial sensitivity to the UCP1 inhibitor GDP was greater in both HCR (P < 0.01) and LCR (P < 0.05) rats randomized to VWR versus control. The BAT proteome differed in CTRL HCR and LCR rats, were there was enrichment in proteins related to branched chain oxidation and mitochondrial fatty acid oxidation in HCR rats. VWR remodeled the BAT proteome, where 151 proteins were differentially expressed in LCR BAT and 209 differentially expressed in LCR BAT following VWR. In both stains, there was an enrichment in proteins related to metabolism mitochondrial function in response to VWR. However, when comparing strains, 39 proteins were differentially expressed in BAT in HCR rats compared to LCR rats in response to VWR. These proteins were related to carboxylic acid and amino acid metabolism. Collectively, inborn fitness impacts body mass and composition, exercise behaviors, and the BAT proteome in early life. Early life exercise alters whole body and BAT energetics irrespective of inborn fitness, augmenting basal and total energy expenditure and BAT thermogenic capacity and function.