Frontiers in aging最新文献

Alzheimer's disease (AD) is a complex neurodegenerative disorder that can be caused by multiple factors, such as abnormal amyloid-beta (Aβ) deposition, pathological changes in Tau protein, lipid metabolism disorders, and oxidative stress. Recent studies have revealed the potential link between gut microbiota and AD, particularly the impact of gut microbiota and its derivatives on microglia. As immune cells in the central nervous system (CNS), microglia are involved in neuroinflammation and the regulation of cognitive function. Research indicates that the dysregulation of gut microbiota may affect the phenotype and function of microglia through various mechanisms, including direct metabolite action and indirect immune and neurotransmitter regulation. This article reviews the direct and indirect effects of gut microbiota and its derivatives on microglia, explores their role in the pathogenesis of AD, and discusses therapeutic strategies based on gut microbiota, such as dietary regulation, probiotics, fecal microbiota transplantation, and traditional Chinese medicine. Although existing studies have shown the potential of these interventions, further research is needed to completely understand their application in the treatment of AD.

Age-related strength loss is more strongly tied to reduced muscle quality than muscle mass. Echo intensity (EI) measured by B-mode ultrasonography is a common marker of intramuscular adiposity and fibrous tissue. Although high-intensity resistance training is effective, the added value of higher training volumes on muscle quality and strength in older adults remains unclear. Moreover, previous studies examining EI changes following resistance training have provided mixed results. To resolve these issues, this exploratory study compared the effects of different resistance training volumes on muscle quality, size, and strength among older adults. Twenty-five older adults (14 males, 11 females; mean ± SD age = 70 ± 7 years) were randomized to moderate volume (n = 14; 2 sets per exercise; 12 sets per week) or high volume (n = 11; 6 sets per exercise; 36 sets per week) training groups. Cohort-specific test-retest reliability statistics were determined prior to the intervention. Participants trained twice weekly, performing knee extension, trap-bar deadlift, and leg press at 85% of one-repetition maximum (1RM). Pre- and post-intervention assessments included ultrasonographic measures of the vastus lateralis (VL) and rectus femoris (RF), leg lean mass, knee extension 1RM, isometric and isokinetic quadriceps strength, and functional tests. The results indicated no significant group × time interactions with small-to-moderate effect sizes, suggesting that increasing volume three-fold provided no additional benefit. When collapsed across group, improvements were found for VL EI (p = 0.025, η_p ² = 0.200), VL (p = 0.015, η_p ² = 0.232) and RF cross-sectional area (p < 0.001, η_p ² = 0.440), knee extension 1RM (p < 0.001, η_p ² = 0.794), isometric peak torque (p < 0.001, η_p ² = 0.630), and concentric peak torque at 180°/s (p < 0.001, η_p ² = 0.423) and 300°/s (p = 0.009, η_p ² = 0.263). No changes were observed in RF EI, leg lean mass, or functional performance. Despite large mean changes, only <25% of participants exceeded the minimal difference needed to be considered real for any variable. In summary, 6 weeks of moderate volume resistance training elicits meaningful improvements in muscle quality and strength. EI changes were muscle-specific, suggesting heterogeneous adaptations among older adults.

The relationship between disease onset and chronological age varies between individuals, driving the need for a more accurate, universal biomarker of biological aging. Among the emerging alternatives, the immune system represents a universally shared, complex system that consistently shows aging-related decline across diverse individuals. Specifically, T-cell dynamics, capturing both thymic involution and lifelong antigenic exposure, provide insights into immune system aging. Although existing aging clocks, such as those based on DNA methylation (i.e., Horvath's and GrimAge), offer valuable predictions of biological age and disease risk, these methods are often limited in ability and cost to reflect real-time immune function. We also explore cutting-edge techniques to measure T-cell states, such as flow cytometry, single-cell omics, cytometry by time-of-flight (CyTOF), and the potential of non-invasive retinal imaging, but these techniques also face these limitations. To account for the challenges with the above-mentioned methods, we propose the naive-to-exhausted T-cell ratio as a promising, quantifiable metric of immune aging. The conceptual framework benchmarks the naive-to-exhausted T-cell ratio against established epigenetic clocks, generating an "immune age curve" that offers clinicians and researchers a practical approach to integrate immune aging assessments into clinical and preventative care. To test our hypothesis, we conducted survival association analysis based on naive-to-exhausted T-cell levels across all major cancers (including adrenal carcinoma (HR = 0.19 (CI [0.082, 0.44]), p = 1.92e-5), low-grade glioma (HR = 0.47 (CI [0.33, 0.67]), p = 2.4e-5), and sarcoma (HR = 0.52 (CI [0.35, 0.77], p = 0.000984)). The survival analysis shows that a higher ratio of naive to exhausted T cells is associated with significantly better overall survival rates, with hazard ratios (HRs) ranging from 2.7e-9 to 0.7. These preliminary results support the predictive value of naive-to-exhausted T-cell levels for biological aging and disease progression prediction across multiple organ systems.

Introduction: Neural impairments contribute to age-related weakness, yet strategies complementing practical exercise training to target neuromuscular adaptations are lacking.

Objective: This study aimed to determine if combining maximal mental effort (MME) with elastic band training (EBT) augments neuromuscular adaptions in older women.

Methods: Untrained older women (71 ± 4 years) were randomly assigned to EBT (n = 11), EBT + MME (n = 13), or a control (CON; n = 10) group. EBT and EBT + MME performed 6 weeks of moderate-intensity, total body elastic band training, but EBT + MME imagined a maximal muscle contraction during each exercise. Neuromuscular outcomes including voluntary activation (VA), contractile properties, dynamic strength (1-repetition maximum; 1-RM), and isometric peak torque of the elbow flexors (EF) and knee extensors (KE) were assessed. Additionally, KE and EF cross-sectional area (CSA) and muscle quality were captured, as well as lean mass. Two-way mixed ANOVAs were used to compare groups across time.

Results: VA (p = 0.182) and contractile properties (p > 0.05 for all) remained unchanged. Compared to CON, 1-RM (p = 0.004), KE peak torque (p = 0.034), CSA (p < 0.001 for both), and muscle quality (p = 0.001-0.021) improved in EBT and EBT + MME, but no differences existed between these groups (p > 0.05). Lean mass remained unchanged (p = 0.481-0.753).

Conclusion: Compared to EBT, MME did not result in augmented strength or VA. Future research is needed in sarcopenic or older adults suffering from greater age-related weakness. Despite the short training duration, positive effects of home-based, EBT were found for muscle size, quality, and strength in older women. The promotion of accessible forms of resistance training for older adults, such as EBT, is warranted.

Background: Anserine bursa pain (ABP) is hypothesized to correlate with early-stage knee osteoarthritis (KOA). This research seeks to investigate the link between ABP and the incidence of falls in patients diagnosed with KOA or those at heightened risk of developing this condition.

Method: The study utilized 2-year follow-up data derived from the Osteoarthritis Initiative cohort, a comprehensive multicenter observational investigation. Assessment of ABP was conducted through a tenderness/pain evaluation of the anserine bursa, while fall occurrences were self-reported by participants. Binary logistic regression was conducted, adjusting for confounding variables, and results were expressed as ORs along with their 95% CIs.

Results: Data from 3,654 participants were analyzed, with 33.3% reporting ABP. Throughout the follow-up duration, 1,668 participants recorded instances of falls, 1,986 reported no falls, and 244 experienced recurrent falls annually. The primary outcome focused on incident falls, revealing a significant association between ABP and the odds of incident falls over the 2-year follow-up (odds ratio (OR) = 1.188, 95% Confidence interval (CI): 1.021-1.383, P = 0.026). When recurrent falls were included as an additional outcome, ABP was found to markedly predict the odds of these incidents over the 2-year follow-up (OR = 1.422, 95% CI: 1.065-1.898, P = 0.017). Sensitivity analyses confirmed the robustness of these findings among female participants and those without a prior history of falls.

Conclusion: Within individuals diagnosed with KOA or those at substantial risk for KOA, a significant association exists between ABP and increased odds of falling over the 2-year follow-up.

[This corrects the article DOI: 10.3389/fragi.2025.1716985.].

With the accelerating global population aging, vaccine responsiveness in older adults has emerged as an increasingly critical issue. This review systematically explores age-related changes in immune system function and their impacts on vaccine efficacy. Firstly, we outline the characteristics of immunosenescence and its regulatory effects on vaccine effectiveness from three perspectives: cellular, molecular, and signaling pathway levels. Secondly, we summarize methods for predicting vaccine immune responsiveness (such as biomarkers and advanced immunological assays) and current mainstream strategies for enhancing vaccine immune responsiveness, while enumerating several prominent novel vaccine formulations targeting the older adult population. Finally, we discuss existing controversies and future research directions regarding the study of vaccine responsiveness in older adults, and comprehensively evaluate the current research status of vaccine responsiveness in this demographic. By synthesizing extensive evidence, this review aims to provide new insights into addressing the challenges of vaccinating the older adult population and lay a theoretical foundation for developing more effective immunization strategies tailored to this vulnerable group.

As the global population continues to age, there is an increasing demand for ways to accurately quantify the biological processes underlying aging. Biological age, unlike chronological age, reflects an individual's physiological state, offering a more accurate measure of health-span and age-related decline. This review focuses on four key biochemical markers - C-Reactive Protein (CRP), Insulin like Growth Factor-1 (IGF-1), Interleukin-6 (IL-6), and Growth Differentiation Factor-15 (GDF-15) - and explores how Artificial Intelligence (AI) and biosensor technologies enhance their measurement and interpretation. AI-driven methods including machine learning, deep learning, and generative models facilitate the interpretation of high dimensional datasets and support the development of widely accessible, data-informed tools for health monitoring and disease risk assessment. This paves the way for a future medical system, enabling more personalized and accessible care, offering deeper, data-driven insights into individual health trajectories, risk profiles, and treatment response. The review additionally highlights the key challenges and future directions for the implementation of AI-driven methods in precision aging frameworks.