The Journals of Gerontology, Series A: Biological Sciences and Medical Sciences

ObjectivesThe association between skeletal muscle gene expression and knee osteoarthritis (OA) was examined among older adult participants of the Study of Muscle, Mobility and Aging (SOMMA). MethodsInclusion criteria included knee radiographs and bulk RNA sequencing (RNAseq) in vastus lateralis muscle, resulting in 523 participants (56% female). Radiographic knee OA was determined by Kellgren-Lawrence (KL) grades. Differential gene expression was analyzed using a control group (KL [≤] 1, n = 326) and two nested case groups: (a) KL [≥] 2 (n = 197), (b) KL [≥] 3 (n = 112). ResultsCompared with controls, there were 27 and 41 genes associated (FDR [≤] 0.05) with KL [≥] 2 and KL [≥] 3, respectively, and 16 genes significantly associated in both contrasts. For 15 of the 16 genes, the association magnitude was larger with more severe OA (KL [≥] 3). Genes associated in both contrasts included brain-derived neurotrophic factor (BDNF) and interferon regulatory factor-2 (IRF2). Gene sets enriched in KL [≥] 2 and KL [≥] 3 contrasts included DNA repair and branched chain amino acid (BCAA) catabolism. ConclusionsOur results in older adult SOMMA participants indicate that knee OA is associated with genes and pathways expressed in skeletal muscle that are involved in pain sensitization, BCAA catabolism, muscle function preservation, calcium transport and storage, inflammation, and extracellular matrix remodeling. Additional longitudinal studies will be needed to determine how these genes could affect the progression of knee OA.

BackgroundPrediabetes is highly prevalent in older adults and is characterized by heterogeneous clinical trajectories, including regression to normoglycemia and progression to diabetes. While prediabetes has been associated with impaired physical function and frailty, the longitudinal impact of both a single diagnosis and dynamic glycemic transitions on functional outcomes remains unclear. We aimed to evaluate associations between baseline prediabetes and glycemic transitions over time with trajectories of functional capacity and frailty in older adults. MethodsWe conducted a pooled analysis of harmonized data from five nationally representative longitudinal aging cohorts (MHAS, HRS, CHARLS, ELSA, CRELES) within the Gateway to Global Aging Data, including adults aged [≥]50 years with [≥]1 HbA1c measurements. Prediabetes was defined per ADA criteria (HbA1c 5.7-6.4%). Functional outcomes included activities of daily living (ADL), instrumental ADL (IADL), and frailty assessed using Fried phenotype, FRAIL scale, and a deficit-accumulation Frailty Index (FI). Mixed-effects Poisson models estimated incidence rate ratios (IRRs) for baseline prediabetes, while generalized estimating equations assessed time-varying glycemic status and transition trajectories. Models were adjusted for age, sex, cohort, and time-varying covariates, with sensitivity analyses including BMI, smoking, and alcohol intake. FindingsAmong 18,571 participants (median follow-up 13.6 years), baseline prediabetes was associated with increased progression of functional deficits and frailty compared with normoglycemia, including higher FI values and accelerated FI progression. Prediabetes was associated with higher incidence of ADL, IADL, and multimorbidity deficits from early follow-up, although time-dependent changes in incidence rates were not significant. In time-varying analyses (n=7,840), both prediabetes and diabetes were associated with higher incidence of functional deficits compared with normoglycemia, with diabetes showing the strongest effects across all outcomes. Diabetes was associated with greater FI burden and accelerated progression, whereas prediabetes showed a smaller increase, with attenuation over time. Among individuals with baseline prediabetes, regression to normoglycemia occurred in 20.8% and was associated with increased incidence of ADL and frailty deficits. In contrast, progression to diabetes occurred in 24.3%, and was associated with lower risk of incident ADL and Fried frailty deficits compared to stable prediabetes. InterpretationPrediabetes is associated with increased risk of functional decline, frailty, and deficit accumulation in older adults, independent of progression to diabetes. Regression to normoglycemia was associated with higher risk of functional deterioration. These findings suggest that prediabetes reflects a state of metabolic vulnerability linked to biological aging rather than solely a precursor to diabetes and highlights a need to reframe its clinical significance in older populations. FundingThis research was supported by Instituto Nacional de Geriatria in Mexico. RESEARCH IN CONTEXTO_ST_ABSEvidence before this studyC_ST_ABSWe searched PubMed up to April 1, 2026, using the terms ("prediabetes") AND ("frailty" OR "functional decline" OR "activities of daily living" OR "mortality") AND ("older adults" OR "aging" OR "longitudinal" OR "cohort"). Existing evidence from predominantly single-country and cross-sectional studies suggests that prediabetes is associated with increased risk of frailty, disability, and adverse health outcomes in older adults. However, findings have been inconsistent, particularly regarding incident versus prevalent outcomes and the role of competing risks in aging populations. Importantly, few studies have used harmonized multinational longitudinal data, incorporated repeated measures of glycemic status, or evaluated multiple complementary frailty constructs. The impact of dynamic glycemic transitions, including regression to normoglycemia and progression to diabetes, on functional trajectories remains poorly understood. Added value of this studyThis study leverages harmonized longitudinal data from five nationally representative aging cohorts from Mexico, England, China, Costa Rica and the United States to examine both baseline prediabetes and time-varying glycemic status in relation to trajectories of functional decline and frailty. By integrating multiple validated measures of functional capacity and frailty, and applying longitudinal modeling strategies, we provide a comprehensive assessment of the relationship between prediabetes and age-related outcomes. We further characterize glycemic transition trajectories and show that regression to normoglycemia among older adults with prediabetes is associated with increased risk of frailty, while progression to diabetes does not uniformly confer additional risk beyond stable prediabetes. Implications of all the available evidenceOur results support a reconceptualization of prediabetes in older adults as a marker of systemic vulnerability rather than solely a precursor to diabetes. Glycemic status in later life appears to also reflect underlying physiological reserve, with dynamic changes potentially signaling deterioration rather than improvement. Our findings suggest a need to incorporate glycemic markers into geriatric risk stratification and to interpret their changes in the context of aging biology. Future research should focus on elucidating the mechanisms linking dysglycemia with frailty and functional decline, including the roles of sarcopenia, inflammation, and multimorbidity, and on evaluating interventions tailored to older populations across diverse global contexts.

The VACS 2.0 Frailty Index was developed using the VA health records system to identify frailty and predict mortality in older Veterans that were living with HIV. Systemic inflammatory indices have been associated with frailty, but little is known about the association between frailty and immunosenescence. We aim to investigate the potential link between soluble inflammatory indices, T cell expression of exhaustion and senescence markers, and frailty as measured by the VACS 2.0 index. We analyzed a one-time blood draw for plasma levels of inflammatory indices, T cell subsets and expression of exhaustion and senescence markers, and calculated VACS 2.0 index scores in a cohort of 30 older (>65 years) Veteran participants. We found that VACS 2.0 scores correlated with the number of prescribed medications in the older Veterans. Soluble TNF receptor levels strongly correlated with VACS 2.0 frailty scores. How these soluble TNF receptors are generated and whether they mechanistically contribute to frailty warrants further investigation.

BackgroundSarcopenia is associated with impaired physical function. Dual-task conditions, which increase cognitive demand during motor performance, may reveal deficits in neuromuscular control that are not evident during isolated motor tasks. Therefore, we investigated whether older adults with sarcopenia exhibit poorer steadiness of force and neural control (i.e., greater motor unit discharge variability, and altered common synaptic input) during submaximal contractions performed under single- and dual-task conditions compared with non-sarcopenic controls and master athletes. MethodsFifty-two older adults were included (74.3{+/-}7.3 years; 50% female). Sarcopenia was defined using Sarcopenia Definitions and Outcomes Consortium criteria based on low grip strength and slow gait speed. Participants (11 with sarcopenia, 22 controls, and 19 masters athletes) performed six sustained isometric ankle dorsiflexion contractions at 30% maximal voluntary torque, three under single-task conditions and three during concurrent serial number subtraction. High-density surface electromyography was recorded from tibialis anterior, and motor unit spike trains were decomposed and tracked across trials. Outcomes included torque coefficient of variation, mean discharge rate, inter-spike interval coefficient of variation, and intramuscular coherence in the delta (1-5 Hz), alpha (5-15 Hz), and beta (15-35 Hz) bands. ResultsSarcopenic individuals had worse torque steadiness (increased torque coefficient of variation) than controls (45-84%) and athletes (39-105%) during single-task, which worsened further (+35% relative to baseline) during dual-tasking. Mean discharge rates (proxy of neural drive) slightly increased during dual-tasking in all groups by [~]2.6%, with no between-group differences. Discharge rates coefficient of variation (Proxy of neural control unsteadiness) increased 5.5% in sarcopenia, was unchanged in controls, and decreased 4.1% in athletes during dual-tasking. Delta-band coherence decreased 5.5% during dual-tasking across all groups. Alpha-band coherence increased only in sarcopenia during dual-tasking (20.6%). Beta-band coherence increased 20.6% in sarcopenia but decreased 3.6% in controls and 3.8% in athletes during dual-tasking. ConclusionsOlder adults with sarcopenia exhibit poorer force and neural control steadiness, and both deficits worsen under cognitive load. These changes are accompanied by alterations in common synaptic input, particularly an increase in physiological involuntary tremor-related oscillations (alpha band), which contribute to greater force unsteadiness. Neural control unsteadiness during dual-task performance may therefore represent a neural feature of sarcopenia-related functional impairment. Assessing neuromuscular control during cognitively demanding tasks may improve detection of neural dysfunction and identify mechanistic targets for interventions to reduce mobility impairment and fall risk. These findings support expanding muscle-centric views of sarcopenia to include neural mechanisms of motor control.

BackgroundThe Eatwell Guide represents the UKs principal healthy eating model and understanding whether adherence to UK dietary recommendations can attenuate age-related functional decline is essential to inform healthy ageing strategies. MethodsIn up to 157,457 participants from the UK Biobank, we explored cross-sectional and prospective associations between adherence to the Eatwell Guide and markers of physical function (grip strength, fat-free mass percentage, self-reported walking pace, and falls). Eatwell Guide adherence scores were derived from 24-hour dietary recall data (Oxford WebQ), and quantified using a graded, food-based scoring system. Differences between population subgroups including by age, sex, physical activity, and protein intake level were explored. ResultsHigher Eatwell Guide adherence was cross-sectionally associated with higher grip strength, greater fat-free mass percentage, higher odds of brisk walking pace, and lower odds of falls (all p<0.001). Prospectively, greater adherence was associated with attenuated fat-free mass decline ({beta}=0.02, SE=0.001, p<0.001) and slower grip strength decline ({beta}=0.01, SE=0.002, p<0.01). Higher adherence was also prospectively associated with greater odds of brisk walking pace (OR=1.02, 95% CI: 1.017-1.021, p<0.01), though this advantage attenuated over follow-up (EWG*Time: OR=0.998, 95% CI: 0.997-0.999, p=0.002). Higher adherence was prospectively associated with lower falls risk (OR=0.996, 95% CI: 0.995-0.998, p<0.001), with this protective association remaining stable over time (EWG*Time: p=0.89). ConclusionsHigher Eatwell Guide adherence was associated with preserved muscle mass, modest attenuation of grip strength decline over time, and a reduced risk of falls, supporting its relevance for musculoskeletal health and physical function in ageing populations.

Background: Regular exercise is a highly effective yet underutilized strategy to reduce cardiometabolic disease burden. Whether brief structured exercise programs confer lasting cardiometabolic benefits remains unclear. The STRRIDE-Prediabetes Reunion study examined legacy effects of exercise training on cardiorespiratory fitness, body composition, and cardiometabolic health. Methods: Seventy-three participants (71.3 {+/-} 7.2 years; 64% women; 77% White) completed Reunion assessments ~11 years after completing one of four 6-month interventions differing in exercise amount, intensity, and inclusion of diet-induced weight loss. Linear mixed effects models evaluated longitudinal trajectories; secondary analyses examined baseline-adjusted associations among short-term intervention response and Reunion outcomes. Results: Abdominal adiposity improved across all groups from baseline to Reunion, with waist circumference decreasing ~3 cm over the follow-up period. In contrast, cardiorespiratory fitness and fat-free mass declined significantly. A significant group by time interaction was observed for total fat mass (p=0.01), with continued fat mass reductions observed in women randomized to high amount exercise. After baseline adjustment, greater short-term intervention response was associated with more favorable Reunion outcomes across fitness, body composition, and cardiometabolic domains; fat-free mass showed the strongest association ({beta}=0.84, p<0.0001). Conclusions: In older adults with prediabetes, the STRRIDE-Prediabetes interventions produced several legacy health effects persisting more than a decade later. Legacy effects differed by sex and exercise dose, and short-term intervention response relative to baseline was associated with long-term outcomes, supporting targeted exercise strategies to preserve cardiometabolic health and functional independence with aging.

Background: It is an everyday observation that people of the same chronological age differ with respect to their physical and mental capacity. However, assessing these differences in biological age remains challenging. Methods: Here, we aggregate 89 age-associated variables from the Berlin Aging Study II (BASE-II, n=1,631) to generate MultiAge, a new marker of biological age that summarizes information from ten domains reflecting organ health and global biological age. We then used methylation data obtained from an Illumina MethylationEPIC array and supervised machine learning to translate MultiAge into a DNA methylation signature, MultiAgeEpi (309 CpGs), which was subsequently validated in four independent external validation cohorts (KORA FF4, KORA Age, SHIP-TREND, BiDirect, total n=4,339). MultiAgeEpi results were compared with previously published epigenetic clocks (GrimAge, DunedinPACE, SystemsAge). Results: We report that MultiAgeEpi showed similar, and in several cases, stronger associations with age-associated outcomes such as diabetes, metabolic syndrome, multimorbidity, frailty and mortality (q < 0.05) compared to the other clocks. Conclusions: MultiAge and MultiAgeEpi thus provide a comprehensive assessment of biological age through aggregation of numerous age-associated variables and the use of the high-resolution methylomics data makes transfer of this marker to other cohorts possible.

Motoric Cognitive Risk (MCR) syndrome, defined by subjective cognitive complaints and slow gait speed, identifies older adults at increased risk of major neurocognitive disorders (NCDs). Yet, gait speed reflects a composite output shaped by heterogeneous neuromusculoskeletal and cognitive processes, limiting its clinical specificity. This study aimed to refine the motor signature of MCR by quantifying domain-specific gait deviations relative to a normative reference cohort using an anomaly detection approach. Ninety-seven adults ([&ge;] 55 years) completed two 3-minute treadmill walking bouts at their preferred speed. Participants were categorized into three groups: older adults with MCR (n = 20), healthy older adults with slow gait (sHOA; n = 20) matched to MCR for age and gait speed, and healthy older adults (HOA; n = 57). Linear spatiotemporal and nonlinear trunk acceleration-derived variables were organized into ten functional gait domains, conceptually grouped into gait pattern (pace, rhythm, phases, postural control, symmetry), fluctuation amplitude (variability), and temporal structure of fluctuations (regulation, signal complexity, divergence of movement trajectories, and attractor complexity). For each domain, a Gaussian mixture model trained on HOA data defined a normative reference space, from which individual anomaly scores quantified deviations across groups. Both sHOA and MCR showed higher deviations in gait pattern domains (pace and phases) than HOA, consistent with their slower gait speed. Only MCR exhibited additional deviations in domains related to fluctuation amplitude and temporal structure, reflected by increased step-to-step variability and trunk acceleration fluctuations that were more divergent, more predictable, and less complex. These findings reveal a multidimensional motor signature of MCR. Domain-specific anomaly scores may provide individualized, clinically interpretable biomarkers to support early detection and monitoring of older adults at increased risk of major NCDs. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=109 SRC="FIGDIR/small/716304v1_ufig1.gif" ALT="Figure 1"> View larger version (42K): org.highwire.dtl.DTLVardef@3b2e52org.highwire.dtl.DTLVardef@15e4101org.highwire.dtl.DTLVardef@fdb9c4org.highwire.dtl.DTLVardef@1af0d03_HPS_FORMAT_FIGEXP M_FIG C_FIG

Background: This study investigates whether proteomic aging clocks (PACs) are associated with cerebral small vessel disease (CSVD). Methods: We included participants from two US community-based cohorts: the Atherosclerosis Risk in Communities (ARIC) Study and the Multi-Ethnic Study of Atherosclerosis (MESA) Study. These analyses leveraged PACs that were developed in ARIC using proteomics measured by SomaScan in midlife (Visit 2; mean age 56 y; n=1,486) and late-life (Visit 5; mean age 76 y; n=1,496), trained on chronological age. Proteomic age acceleration (PAA) was calculated as residuals from regressing PACs on chronological age. 3T brain MRI data were collected in late-life. We examined associations of PAA with log-transformed white matter hyperintensity (WMH) volume using linear regression and with the presence of microbleeds, and subcortical, lacunar, and cortical infarcts using logistic regression. Associations of PACs with WMH volume and microbleeds were tested in MESA using proteins measured at Exam 1 (mean age 57 y; n=932) and Exam 5 (mean age 66 y; n=934). All associations were quantified per 5-year increase in PAA. All models were adjusted for demographics and cardiovascular risk factors. Results: In ARIC, higher midlife PAA was associated with greater WMH volume (percent difference: 25% [95% CI: 13%, 39%]) and higher odds of subcortical infarcts (OR: 1.24 [1.02, 1.51]). Late-life PAA was associated with all CSVD markers: WMH volume (percent difference: 20% [8%, 34%]), cerebral microbleeds (OR: 1.40 [1.15, 1.69]), subcortical (OR: 1.80 [1.47, 2.22]), lacunar (OR: 1.80 [1.46, 2.23]), and cortical infarcts (OR: 1.39 [1.07, 1.82]). In MESA, higher late-life PAA was associated with greater WMH volume (28% [3%, 58%]) but not with microbleeds. Conclusion: Accelerated proteomic aging is associated with a higher prevalence of MRI markers of CSVD, most predominantly in late-life. Understanding this relationship may help stratify those at higher risk of CSVD at an early stage.

BackgroundSkeletal muscle aging exhibits substantial heterogeneity, with some individuals maintaining robust function into advanced age while others develop sarcopenia and frailty. Whether molecular signatures distinguishing these trajectories reflect biological aging or modifiable factors, such as physical activity, remains unclear. MethodsAn integrated discovery-validation study was conducted on skeletal muscle transcriptomes. Discovery analysis used the GSE144304 dataset comprising vastus lateralis biopsies from young adults (n=26, aged 18-30 years), fit elderly (n=30, aged 65-80 years with preserved function), and frail elderly (n=24, aged 65-80 years stratified by grip strength). Top 10 most significantly altered genes were validated across five independent transcriptomic studies (n=184 total) strategically selected to represent distinct activity contexts: activity-controlled aging, sedentary aging, mixed-activity aging, disease-impaired aging, and exercise intervention. Expression of two established atrogenes were examined (FBXO32/Atrogin-1 and TRIM63/MuRF-1) as benchmarks. ResultsDiscovery analysis identified 10 genes with profound age-related changes (adjusted p < 10-{superscript 2}{superscript 1}, |log2FC| > 1.3). Cross-dataset validation revealed striking activity-dependence: genes downregulated with aging in sedentary populations (MYORG, STRADB) showed maintained or increased expression in active elderly individuals (80% validation rate, r = 0.75-0.82 with activity level). In contrast, established atrogenes showed poor replication (25-50%) and context-dependent patterns. C4ORF54 expression strongly correlated with grip strength (r = 0.68, p < 0.001), with age effects disappearing after phenotype adjustment, indicating purely phenotype-mediated expression. Critically, sedentary versus active aging datasets showed opposing transcriptional patterns (r = -0.68), demonstrating that activity confounds conventional age-based signatures. ConclusionsMolecular signatures distinguishing fit from frail aging predominantly reflect physical activity levels rather than inevitable biological processes. MYORG and STRADB emerge as activity-responsive biomarkers of muscle health, while C4ORF54 serves as an indicator of functional capacity. These findings challenge conventional atrogene paradigms and suggest that exercise-responsive AMPK signaling pathways represent immediately translatable therapeutic targets for preserving muscle function in older adults.

While bone mineral density (BMD) remains the clinical standard for assessing age-related fracture risk, accumulating evidence indicates that bone quality, including matrix properties and microarchitecture, contributes to fracture susceptibility in ways not captured by BMD alone. As matrix-targeted therapeutics emerge, preclinical models that exhibit translationally relevant bone quality changes are needed. Here, we evaluated the Fischer 344 x Brown Norway (F344xBN) F1 rat, a strain characterized by hybrid vigor and non-pathological aging, as a model for studying matrix-related mechanisms of skeletal aging. Femurs from male and female rats aged 7, 15, and 22 months were analyzed to quantify age- and sex-dependent changes in bone microarchitecture, fracture resistance, and matrix properties. Microcomputed tomography analyses revealed sexually dimorphic aging trajectories. From 7 to 22 months, females exhibited moderate declines in trabecular microarchitecture and no change in cortical porosity, whereas males showed pronounced trabecular deterioration and increased cortical porosity. Whole-bone flexural testing demonstrated age-related declines in material properties that were not attributable to changes in geometry, while females maintained geometry-scaled bone strength. Both sexes exhibited reduced bone toughness with age. Raman spectroscopy identified matrix-level alterations in males by 15 months, whereas systemic markers of bone turnover remained unchanged across age or sex. Together, these findings indicate that males exhibit combined tissue-scale and whole-bone deterioration by midlife, while females exhibit declining fracture resistance preceding substantial cortical bone loss or overt matrix deterioration. These results support the F344xBN F1 rat as a translational model for investigating matrix-driven skeletal aging. Lay summaryF344 x BN F1 hybrid rats provide a healthy, matrix-driven skeletal aging model. This strain exhibits distinct aging trajectories dependent on sex. Strength and toughness decrease in both sexes by midlife. Fracture resistance declines in females prior to substantial bone loss.

Cardiovascular and cerebrovascular risk factors (CVRFs)--including hypertension, diabetes, heart disease, and stroke--are prevalent chronic conditions in older adults and major determinants of late-life cognitive decline. These conditions involve chronic inflammatory and metabolic processes that may accelerate biological aging, reflecting multisystem physiological decline beyond chronological age. We examined associations among CVRFs, accelerated biological aging, and cognitive performance and assessed whether biological aging mediates the association between CVRFs and cognitive performance overall and across race/ethnicity and sex. We analyzed data from 2,384 U.S. adults aged 60 years and older in the National Health and Nutrition Examination Survey 2011-2014. CVRFs were defined using clinical measurements and self-reported diagnoses. Biological aging was quantified using the PhenoAge algorithm derived from blood-based clinical biomarkers. Cognitive performance was assessed using composite scores of memory, executive function, and processing speed. Weighted linear regression and causal mediation analyses were conducted overall and stratified by race/ethnicity and sex. All CVRFs were associated with accelerated biological aging, with diabetes demonstrating the strongest association (0.76 SD higher PhenoAge acceleration; 95% CI: 0.67-0.85). CVRFs were associated with lower cognitive performance, with stroke showing the largest association ({beta} = -0.317; 95% CI: -0.471 to -0.165). Accelerated biological aging mediated these associations, accounting for 88.5% of the diabetes association and 13.7%-27.2% for other CVRFs. Associations and mediation effects varied across racial/ethnic and sex groups, with mediation more consistent among Non-Hispanic Whites and females. Accelerated biological aging represents an important link between cardiometabolic risk to cognitive performance in older adults.

BackgroundAgeing is associated with reduced resilience to physiological stressors such as infection and surgery. This reduced resilience is believed to be underpinned by the hallmarks of ageing, the key biological mechanisms driving the aged phenotype. Geroprotectors are drugs that are proposed to slow down the ageing process and promote longevity and healthspan. Despite this, mechanistic studies in healthy older adults are lacking. Methods and AnalysisThis trial will test the hypothesis that geroprotectors targeted towards biological mechanisms associated with poor resilience can reverse these pathways within a three-week period. Three geroprotectors with a good safety profile in older adults and evidence of effect on the hallmarks of ageing will be administered to 60 (30 female; 30 male) adults 70+. Participants will be randomised to one of three arms (Metformin MR 1500mg, Fisetin 100mg or Spermidine 15mg). Participants will be extensively clinically characterised at baseline. Blood, abdominal adipose tissue and stool samples will be taken at baseline and following the three-week intervention. The primary research question will answer whether a three-week course of Metformin, Spermidine, or Fisetin reduce the number of senescent cells as measured by SA-{beta}-GAL in adipose biopsies in healthy older volunteers. Additionally, there will be assessment of the effect of the geroprotectors on other hallmarks of ageing, including autophagy, immunosenescence, chronic inflammation, dysregulated mTOR signalling, epigenetic age, DNA damage, dysregulated metabolism, stem cell exhaustion and microbial composition. Ethics and DisseminationEthical approval is in place (24/LO/0549). The main trial report and any sub-studies will be published in high impact peer-reviewed gerontology journals, presented at academic conferences and through a series of public engagement events. Participants enrolled in the study will be informed of the results by a written summary. Trial RegistrationREPROGRAM was registered with ISRCTN on 10/09/24. ISRCTN47919839. Available at https://www.isrctn.com/search?q=47919839. Trial Registration Data Set O_TBL View this table: org.highwire.dtl.DTLVardef@1db6074org.highwire.dtl.DTLVardef@1997837org.highwire.dtl.DTLVardef@a39a11org.highwire.dtl.DTLVardef@d7e6eforg.highwire.dtl.DTLVardef@7a5b7f_HPS_FORMAT_FIGEXP M_TBL O_FLOATNOTable 1C_FLOATNO O_TABLECAPTIONTrial Registration Data Set C_TABLECAPTION C_TBL

Background: Sleep problems are common in older people and have been associated with increased fall risk, but the mechanisms underlying this relationship remain unclear. Gait quality reflects balance control and neurological function and may provide insight into pathways linking sleep health and falls. Methods: Data from 758 community-dwelling older people ([&ge;]65 years; mean age 75.8 years, 69.3% women) were analysed. Sleep problems were assessed at baseline using a self-reported item (Patient Health Questionnaire-9, question 3). Daily-life gait quality and habitual walking speed were derived from one week of wearable sensor monitoring. Falls and injurious falls were prospectively recorded over 12 months. Associations between sleep problems, gait quality, and fall incidence were examined using regression models adjusted for demographic, pain and cognitive factors, and use of sleeping medication. Results: Sleep problems were reported by 43.9% of participants. Sleep problems were not associated with habitual walking speed, but were associated with lower gait quality in daily life (adjusted {beta} = -0.15, 95% CI -0.27 to -0.03). Participants reporting sleep problems had higher incidence rates of total falls (adjusted IRR = 1.42, 95% CI 1.07 to 1.90) and injurious falls (adjusted IRR = 1.50, 95% CI 1.07 to 2.10). Conclusions: Self-reported sleep problems were associated with impaired real-world gait quality and substantially higher rates of falls and injurious falls in older people. These findings suggest that sleep problems may increase fall risk by altering balance control rather than by reducing walking speed. Sleep should be considered when managing fall risk, and fall risk should be considered in older people with sleep complaints.

Background: Epigenetic clocks based on DNA methylation (DNAm) have emerged as promising biomarkers of biological aging, yet their associations with cognitive performance remain inconsistent. This study investigates the relationship between epigenetic age acceleration and cognitive performance in older adults using 14 DNAm clocks from five generations of development. Methods: We analyzed data from the Berlin Aging Study II (BASE-II) using genome-wide DNAm profiles and cognitive assessments ascertained at baseline (T0) and two follow-up time points (T1, T2) in up to 1,014 individuals. DNAm-based age and age acceleration estimates were calculated using Biolearn and MethylCIPHER. Analyses focused on cross-sectional and longitudinal associations between DNAm clock estimates and cognitive performance, including sex-specific effects and comparisons with frailty as non-cognitive positive control. Results: Among all tested DNAm clocks, DunedinPACE (a third-generation clock) showed the strongest and most consistent associations with cognitive performance. In addition, the fifth-generation SystemsAge framework also demonstrated robust associations with cross-sectional and longitudinal cognitive outcomes. In contrast, second-generation clocks (GrimAge [v2], PhenoAge) showed occasional nominal associations, while first-generation clocks (Horvath [v1], Hannum) and the causally-informed, fourth-generation clocks (e.g. YingCausAge, YingDamAge) showed no noteworthy signals. Likewise, telomere length estimated from DNAm was not strongly associated with cognitive performance in this dataset. Conclusions: Our findings highlight DunedinPACE as a particularly informative biomarker for various aspects of cognitive aging, while other DNAm aging measures showed no consistent associations. Future work should further refine domain-specific epigenetic biomarkers to improve biological aging assessments and achieve a more reliable early detection of cognitive decline.

Skeletal muscle mass and training adaptations decline with aging, yet the proteomic basis of these attenuated responses remains unclear. We hypothesized that aging is accompanied by diminished proteome plasticity in response to resistance training (RT). The soluble proteome of VL biopsies was profiled in 17 younger (21.9 {+/-} 2.5 yr) and 15 older (57.5 {+/-} 6.9 yr) untrained males before and after 10-12 weeks of supervised RT using data-independent acquisition mass spectrometry (2,113 quantified proteins). At baseline, we detected 196 differentially expressed proteins (DEPs) significantly differed between age groups by {Pi}-score (278 by FDR). A 5.6-fold difference in training-responsive was observed in younger vs. older adults (100 vs. 18 {Pi}-score DEPs; 134 vs. 0 FDR-significant). Despite this quantitative attenuation, 61.6% of proteins changed in the same direction in both age groups (Spearman {rho} = 0.284, p = 3.46 x 10-), indicating conserved but amplitude-compressed training responses (median |log2FC|: 0.13 young vs. 0.09 old). RT in older adults partially reversed the aging proteome in that directionally different changes were observed in 75.2% of aging- or training-significant proteins in aging and training contrasts, with ribosomal and translational machinery showing the strongest reversal (cytoplasmic translation NES: -2.90 with aging, +2.60 with training). Ten WGCNA co-expression modules were identified, with age emerging as the dominant organizing principle (Turquoise module r-equiv = +0.59, p < 0.001). Module eigengenes discriminated age groups at the univariate level (Turquoise/Lipid Catabolism AUC = 0.96, q < 0.012), and training-induced module changes correlated with hypertrophic outcomes. Aging markedly attenuates but does not qualitatively alter skeletal muscle proteome plasticity. RT partially reverses aging proteome signatures, with translational machinery being the most responsive and mitochondrial programs the least responsive. Baseline proteomic state constrains adaptive capacity, suggesting that the molecular features distinguishing aging muscle directly may limit its hypertrophic response to RT.

Background: Circadian rest-activity rhythms weaken with age, but whether sleep disorders modify this trajectory is unknown. Methods: We analyzed wrist accelerometry data from 4,386 participants aged 6-80 years in the 2011-2012 National Health and Nutrition Examination Survey (NHANES). Circadian features were extracted using cosinor analysis and nonparametric methods; a Circadian Disruption Index (CDI) was constructed from five standardized components. Survey-weighted regression with natural cubic splines and Wald F-tests tested age-by-sleep-disorder interactions using Taylor series linearization for variance estimation. Results: Doctor-diagnosed sleep disorder (N = 360, 8.2%) was associated with significantly different age-related trajectories of amplitude (F(2,17) = 11.24, p = 0.0008) and MESOR (F(2,17) = 8.22, p = 0.0032), both surviving Bonferroni correction (p < 0.006). CDI was higher in those with a sleep disorder (0.290 vs. 0.131, p < 0.001) and was independently associated with higher BMI (beta = 1.33 kg/m2, p < 0.001), higher HbA1c (beta = 0.089%, p = 0.004), greater diabetes prevalence (beta = 3.8 percentage points, p < 0.001), and worse depressive symptoms (beta = 0.43 PHQ-9 points, p = 0.020). Sensitivity analyses using a broader sleep problem exposure did not replicate these interactions. Conclusions: Doctor-diagnosed sleep disorders are associated with an altered age-related decline in circadian amplitude and mean activity level. CDI was independently linked to cardiometabolic and depressive outcomes, supporting a mechanistic connection between clinically significant sleep pathology and circadian disruption across the lifespan.

IntroductionLife expectancy for people with type 1 diabetes has increased due to improved treatment of diabetes and its comorbidities, allowing many to reach old age. Still, we lack knowledge of how individuals with type 1 diabetes age. On one hand, those who reach older age can be considered survivors, but on the other hand their long-standing diabetes might still exhibit negative impacts on their health and functional ability. Healthy ageing is the World Health Organizations priority for this decade. The focus has shifted from chronological age to functional ability, which reflects the ability of individuals to perform meaningful activities. Functional ability is shaped by intrinsic capacity, the environment, and their interaction. Intrinsic capacity encompasses five main domains: cognition, vitality, sensory function, locomotion, and psychological domain. This observational study aims to assess how this vulnerable group of individuals with type 1 diabetes age and to identify factors that contribute to their healthy ageing, intrinsic capacity, and its domains. Methods and analysisThe FinnDiane LifeOne Study is a prospective observational cohort study. We aim to recruit a minimum of 300 individuals with type 1 diabetes from the FinnDiane Study, aged >65, and a minimum of 100 matched controls without insulin-dependent diabetes. The cohort will be comprehensively characterized, including clinical assessment, laboratory tests, questionnaires, and a geriatric assessment of different aspects of functioning ability, with five years intervals. We will compare the individuals with type 1 diabetes to their matched controls. For those with type 1 diabetes, we will further assess which factors from the FinnDiane baseline and trajectories during follow-up predict healthy ageing in above 65-year-olds. Ethics and disseminationThe LifeOne study protocol is approved by the Ethics Committee of HUS Helsinki University Hospital (HUS/4387/2023) and the study adheres to the Declaration of Helsinki. Written informed consent is obtained from each participant. Findings will be published in international peer-reviewed journals with an open access choice. The study is registered at ClinicalTrials.gov with ID NCT07289204. STRENGTHS AND LIMITATIONS OF THE STUDYO_LIThis is a prospective observational cohort study with a matched control group. C_LIO_LIFor the participants with type 1 diabetes, we have unique and comprehensive longitudinal clinical and genetic data available from approximately participants middle age, enabling identification of factors that contribute to their healthy ageing, while accounting for the competing risk of death. C_LIO_LIThe cohort is thoroughly characterised regarding diabetes, cardiometabolic health, lifestyle, psychosocial factors, and includes a geriatric assessment, thereby enabling comparison of impact of ageing between individuals with type 1 diabetes and controls without insulin-dependent diabetes. C_LIO_LIThe cohort is Caucasian with recruitment from Southern Finland, potentially limiting generalisability to other more ethnically diverse populations. C_LI

Abstract Importance: Irregular sleep-wake patterns have been associated with poor health and cognitive outcomes, yet evidence linking 24-hour sleep-wake regularity to cognitive decline or dementia remains inconsistent. Particularly, regularity can be measured as regularity of rest-wake, sleep-wake or overall 24-hour activity, but it is unclear which aspects are most relevant for cognitive aging. Objective: To assess associations of rest-wake, sleep-wake, and 24-hour activity regularity with cognitive decline and dementia risk. Design: Observational prospective study comprised of six US and European cohorts: MrOS (sleep study between 2003-2005, mean follow-up: 7.1 years), Rotterdam Study (2004-2007, 11.6 years), MESA (2010-2013, 8.2 years), MAP (2005-2018, 7.2 years), Whitehall II (2012-2013, 6.9 years), and UKB (2013-2015, 7.9 years). Setting: Cohort-specific estimates were pooled using random-effects meta-analysis. Analyses were done between June 2025 and March 2026. Participants 74,733 dementia-free adults with multi-day actigraphy were included across cohorts: MrOS (age: 67-96 years, female:0%), MESA (54-95y, female:54.6%), Rotterdam Study (46-98y, female:55.0%), MAP (56-100y, female:77.1%), Whitehall II (59-83y, female:25.9%), and UKB (55-78y, female:55.5%). Exposure: Day-to-day rest-wake regularity (Rest Regularity Index, RRI), day-to-day sleep-wake regularity (Sleep Regularity Index, SRI), and 24-hour activity regularity (Interdaily Stability, IS) were derived from multi-day actigraphy. Main Outcome: Outcomes were risk of dementia and changes in global cognition. Results: Across six cohorts, 1,906 dementia cases occurred among 74,733 participants. After adjusting for demographics, health behaviors, depressive symptoms and cardiovascular comorbidities, each 1-SD higher regularity score was associated with an 9-14% lower dementia risk (pooled hazard ratios: RRI 0.86 95%CI: [0.79-0.95]; SRI 0.87[0.79-0.97]; IS: 0.91[0.88-0.95]). Associations were approximately linear. Age-stratified analyses showed directionally stronger associations among adults aged < 65, although meta-regression did not support an interaction(p > 0.55). Greater regularity was associated with modestly slower decline in global cognition (pooled {beta} per 1-SD higher score of RRI per year: 0.003, 95%CI [0.001-0.006]). Conclusions & Relevance: Greater regularity of rest-wake, sleep-wake, and 24-hour activity rhythms was associated with lower dementia risk and modestly slower global cognitive decline. These findings suggest that 24-hour sleep-wake regularity is a relevant behavioral marker of cognitive aging and may inform future efforts to identify or intervene on early risk.

To evaluate whether hemodynamic responses to acute cognitive stress, measured via pulse-wave harmonic analysis, can characterize cardiovascular regulatory coherence and differentiate older adults with mild cognitive impairment (MCI) from cognitively intact individuals, this exploratory cross-sectional observational study utilized a within-session pre-post cognitive task design. A total of 101 community-dwelling older adults in southern Taiwan were stratified by Montreal Cognitive Assessment (MoCA) scores into Reference (MoCA [&ge;]26; n=12, paired n=10), MCI (MoCA 18-25; n=50, paired n=45), and dementia-level (MoCA <18; n=39) groups, the latter being excluded from task-evoked analyses. The primary outcome was the Harmonic Response Consistency Score (HRCS), quantifying the directional uniformity of cardiovascular regulatory responses, alongside secondary measures of harmonic amplitudes (Cn) and phase angles (Pn). Although mean pre-post changes were subtle, response organization differed by cognitive status. The Reference group exhibited high response consistency (mean HRCS = 9.00), characterized by coordinated harmonic down-modulation. Conversely, the MCI group showed attenuated, directionally heterogeneous responses. Compared to the Reference group, the MCI group demonstrated significantly lower HRCS values for the Cn domain (Mean difference: 2.60, 95% CI 0.29-4.91; p=0.020) and PnSD domain (Mean difference: 1.98, 95% CI 0.04-3.92; p=0.030), indicating a breakdown in regulatory coherence. These findings suggest that acute cognitive stimulus reveals coherent harmonic down-modulation in cognitively intact older adults but fragmented responses in MCI. Pulse-harmonic profiling thus serves as a robust physiological index of cardiovascular regulatory coherence, which, when integrated with neuropsychological assessments, may enhance the sensitivity of non-invasive, community-based screening frameworks for early cognitive aging.