Experimental gerontology最新文献

{"title":"Comparative evaluation of time-to-event analysis methods for mobility limitation in older adults: A multi-cohort benchmarking study.","authors":"Jaime Lynn Speiser, Jason R Falvey, Denise K Houston, Peggy M Cawthon, Chixiang Chen, Charles Ginsberg, Deborah M Kado, Michelle C Odden, Sheena Patel, Eleanor M Simonsick, Qian Li Xue, Michelle Shardell","doi":"10.1016/j.exger.2026.113363","DOIUrl":"https://doi.org/10.1016/j.exger.2026.113363","url":null,"abstract":"<p><p>Time-to-event models are central to aging research, quantifying both whether and when an event occurs. However, guidance on selecting among traditional statistical and machine learning (ML) methods for prediction modeling remains limited, particularly for epidemiologic aging cohorts with wide assessment intervals. Mobility limitation, as a clinically important aging outcome with such complexities, provides a relevant test case for methodological benchmarking. We conducted a systematic benchmark comparison of 14 statistical and ML time-to-event methods using harmonized data from four longitudinal U.S. aging cohorts (N = 14,821). The outcome was time to incident mobility limitation, defined by self-reported walking difficulty or gait speed < 0.8 m/s. Models were evaluated using 4-fold cross-validation repeated 100 times within cohorts. Performance metrics captured complementary dimensions of predictive quality: discrimination (C-index), accuracy and calibration (Brier score, integrated log loss, calibration index), and computational efficiency (model training time). Prespecified decision rules synthesize results across metrics to identify preferable methods. Across pooled analyses, multiple methods demonstrated comparable discrimination, including penalized Cox models, tree-based ensembles, and boosting approaches. Oblique random survival forest achieved the most favorable overall trade-off, combining high discrimination (C-index 0.673), good calibration (Brier score 0.147), and moderate training time (9.2 min). When computational efficiency was prioritized, penalized regression methods may be preferable, with good discrimination and Brier score. These findings support random forest and penalized regression as strong defaults for time-to-event prediction modeling in gerontologic research and highlight the importance of joint evaluation of discrimination, calibration, and feasibility.</p>","PeriodicalId":94003,"journal":{"name":"Experimental gerontology","volume":" ","pages":"113363"},"PeriodicalIF":4.3,"publicationDate":"2026-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149221270","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A tablet-based cognitive and physical training intervention to improve postural control for older adults with subjective cognitive decline - a feasibility study.","authors":"Jimmy Falk, Daniel E Sörman, Viktor Strandkvist, Irene Vikman, Anna Stigsdotter Neely, Ulrik Röijezon, Ulrik Röijezon","doi":"10.1016/j.exger.2026.113362","DOIUrl":"https://doi.org/10.1016/j.exger.2026.113362","url":null,"abstract":"<p><strong>Background: </strong>Previous research suggests that adding cognitive training to balance training may improve fall-prevention interventions. This study examined the feasibility and potential effects of a tablet-based intervention comprising balance and strength training alone or combined with cognitive training.</p><p><strong>Methods: </strong>Twenty older adults with subjective cognitive decline who were able to stand and walk unassisted were recruited via social media and senior organizations; 18 completed the study. Participants were allocated to an eight-week tablet-based intervention comprising balance and strength training (BT) or balance and strength training plus cognitive functions (BT + CT). Feasibility outcomes were recruitment, adherence, adverse events, participant experiences and perceived effects. Potential effects on fall-related concerns, cognitive function and postural control were analyzed descriptively.</p><p><strong>Results: </strong>Recruitment met the prespecifies succession criterion. In the BT group, median adherence to balance training and the walking protocol was 75% and 100%, respectively. In the BT + CT group, median adherence was 83% for cognitive training, 54% for balance and strength training, and 170,5% for walking. The interventions were generally well perceived, although the balance training was considered too easy. Descriptive findings indicated that dual-task costs for gait parameters tended to increase in the BT group but decrease in the BT + CT group.</p><p><strong>Conclusion: </strong>Tablet-based interventions targeting cognition and postural control were feasible in several respects among older adults with subjective cognitive decline. Digital tools should be flexible enough to accommodate individual needs, interactive to promote motivation and sufficiently challenging to elicit positive adaptations. Measures of gait variability may be sensitive to subtle changes in postural control.</p>","PeriodicalId":94003,"journal":{"name":"Experimental gerontology","volume":" ","pages":"113362"},"PeriodicalIF":4.3,"publicationDate":"2026-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149217708","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The cardiometabolic ageing-cardiovascular disease axis: A 32-year European study.","authors":"Horia Iuga, Mehmet Ali Balcı, Iulia Cristina Iuga, Sorin-Ciprian Teiușan, Ömer Akgüller","doi":"10.1016/j.exger.2026.113357","DOIUrl":"https://doi.org/10.1016/j.exger.2026.113357","url":null,"abstract":"<p><strong>Background: </strong>Cardiometabolic ageing encompasses the population-level coexistence of diabetes, obesity, and demographic ageing within the analytical framework of this study. We examined whether this profile, summarized by a Diabetes-Obesity-Ageing (DOA) index, was associated with cardiovascular disease (CVD) burden and whether this association varied with national income.</p><p><strong>Methods: </strong>We analysed a balanced panel of 27 European Union countries from 1990 to 2021. DOA was calculated as the equally weighted mean of pooled z-scores for age-standardized diabetes prevalence, age-standardized obesity prevalence, and the proportion aged ≥65 years. The ageing component represented demographic composition. Two-way fixed-effects models examined associations with age-standardized CVD disability-adjusted life-year and mortality rates, including an interaction between DOA and ln(GDP per capita). Sensitivity analyses included alternative estimators, temporal specifications, component-specific models, and PCA-based weighting.</p><p><strong>Results: </strong>The DOA × ln(GDP) interaction was negative and statistically significant in the primary model (β = -0.111; p = 0.006), with a consistent result for cardiovascular mortality (β = -0.118; p = 0.004). Component-specific interactions were significant for diabetes and population ageing, but not obesity. The PCA-based interaction was also negative and significant. Temporal analyses showed a negative interaction in levels models and a positive interaction in short-run specifications. Lead-placebo associations were also significant, while cointegration tests provided mixed evidence of a stable long-run relationship.</p><p><strong>Conclusions: </strong>Higher national income was associated with attenuation of the DOA-CVD relationship in levels models. The composite and component-specific analyses provide complementary perspectives on this pattern, with clearer evidence for diabetes and population ageing. These findings describe an income-dependent population-level association whose interpretation remains sensitive to temporal specification.</p>","PeriodicalId":94003,"journal":{"name":"Experimental gerontology","volume":" ","pages":"113357"},"PeriodicalIF":4.3,"publicationDate":"2026-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149217682","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of muscle length and age on neuromuscular responses to maximal eccentric contractions of the plantar flexors.","authors":"Yohan Betus, Thomas Cattagni, Alexandra Perrin, Julian Colard, Kazunori Nosaka, Anne Sophie Boureau, Guillaume Chapelet, Christophe Cornu, Marc Jubeau","doi":"10.1016/j.exger.2026.113359","DOIUrl":"https://doi.org/10.1016/j.exger.2026.113359","url":null,"abstract":"<p><strong>Introduction: </strong>Eccentric contractions induce greater neuromuscular impairment and muscle damage than concentric contractions. Muscle length is a key modulator of these responses, yet the combined effects of eccentric contractions and muscle length on neuromuscular function in older adults remain unclear. We investigated acute and delayed neuromuscular responses to eccentric plantar flexor contractions performed at different muscle lengths in young and older adults.</p><p><strong>Methods: </strong>Twenty-four young and 26 older adults performed 10 sets of 10 maximal eccentric plantar flexor contractions at either short (30°-0° plantar flexion) or long (0°-30° dorsiflexion) muscle lengths (12 young and 13 older adults per condition). Maximal voluntary isometric contraction, voluntary activation, and evoked responses (100 Hz and 10 Hz doublets) were measured before, immediately after, and 1, 24, and 48 h post-exercise. Changes were compared between groups and conditions.</p><p><strong>Results: </strong>Despite similar torque-time integrals between young and older adults within the same muscle length condition, a muscle length effect was only found in young adults, with a greater (p = 0.021) MVIC decrease at long (-33.6 ± 13.2%) than short lengths (-8.4 ± 15.7%). Older adults showed similar reductions across conditions (≈ - 14-21%). Voluntary activation decreased only at long lengths, with no age difference. Evoked responses showed an age effect (p = 0.032), and the 10/100 Hz ratio decreased only in young after long muscle lengths. Neuromuscular function returned to baseline within 24 h indicating no evidence of severe alteration, although muscle soreness remained elevated at 48 h.</p><p><strong>Conclusion: </strong>Long muscle length eccentric contractions induced greater force loss in young but not older adults, with no evidence of prolonged functional impairment in healthy, physically active older adults.</p>","PeriodicalId":94003,"journal":{"name":"Experimental gerontology","volume":" ","pages":"113359"},"PeriodicalIF":4.3,"publicationDate":"2026-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149217720","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Traditional Chinese mind-body training for bone mineral density in middle-aged and older women: A three-level dose-response Meta-analysis of randomized controlled trials.","authors":"Lin Luo, Xinyi Yin, Chengyu Zhou, Yu Wang, Fuchi Jia, Yongbin Duan","doi":"10.1016/j.exger.2026.113355","DOIUrl":"https://doi.org/10.1016/j.exger.2026.113355","url":null,"abstract":"&lt;p&gt;&lt;strong&gt;Objective: &lt;/strong&gt;This study systematically assessed the effect of Traditional Chinese mind-body training (TCMBT) on bone mineral density (BMD) in middle-aged and older women and examined whether the intervention effects varied by training dose.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Methods: &lt;/strong&gt;PubMed, Web of Science, PsycINFO, the Cochrane Library, and China National Knowledge Infrastructure were searched from database inception to April 2026. Eligible studies were randomized controlled trials that evaluated the effects of TCMBT on BMD in middle-aged and older women. Study selection, data extraction, and risk-of-bias assessment were performed independently by two reviewers. Effect estimates were synthesized using a three-level random-effects model. The stability of the results was examined through influence diagnostics, leave-one-out sensitivity analysis, Egger's test, trim-and-fill analysis, subgroup analysis, linear meta-regression, and Bayesian dose-response modeling.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Results: &lt;/strong&gt;Twenty randomized controlled trials (RCTs) were initially included in the systematic review and primary meta-analysis. Influence diagnostics based on standardized residuals and Cook's distance identified three highly influential RCTs; after excluding these studies, 17 RCTs remained in the final influence-adjusted meta-analysis. The initial pooled analysis showed that TCMBT significantly increased BMD in middle-aged and older women (standardized mean difference [SMD] = 0.55, 95% confidence interval [CI]: 0.24-0.87; P &lt; 0.001), although heterogeneity was substantial (I&lt;sup&gt;2&lt;/sup&gt; = 84.7%). After exclusion of the three highly influential studies, the pooled estimate was reduced but remained positive and statistically significant (SMD = 0.32, 95% CI: 0.22-0.42; P &lt; 0.001). Dose-response analyses suggested potential nonlinear associations between training dose and BMD outcomes; however, these findings should be interpreted as exploratory signals rather than a validated or recommended exercise prescription. In the exploratory XGBoost-SHAP analysis, training frequency, BMD assessment site, and participant age contributed to predictions within the fitted model. This analysis represented in-sample descriptive exploration only, without cross-validation or held-out test data, and therefore cannot support generalizable out-of-sample predictive performance. SHAP values represent within-sample predictive contributions only and should not be interpreted as causal determinants or confirmed moderators of intervention effects.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Conclusions: &lt;/strong&gt;TCMBT appears to have a beneficial effect on BMD in middle-aged and older women, with the most apparent improvement observed at the lumbar spine. The dose-related findings are exploratory and require confirmation in high-quality RCTs before any specific training regimen can be recommended. The XGBoost-SHAP findings are hypothesis-generating only; because the analysis was conducted as an in-sample descriptive ex","PeriodicalId":94003,"journal":{"name":"Experimental gerontology","volume":" ","pages":"113355"},"PeriodicalIF":4.3,"publicationDate":"2026-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149186901","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Corrigendum to \"Bazi Bushen attenuates musculoskeletal degeneration in Ercc1^+/- mice\" [Exp. Gerontol. 225 (2026) 113314].","authors":"Dezhi Huang, Na Xu, Qi Chu, Yan Wang, Zhenhua Jia, Jin Xu","doi":"10.1016/j.exger.2026.113353","DOIUrl":"https://doi.org/10.1016/j.exger.2026.113353","url":null,"abstract":"","PeriodicalId":94003,"journal":{"name":"Experimental gerontology","volume":" ","pages":"113353"},"PeriodicalIF":4.3,"publicationDate":"2026-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149186908","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of 12-week training and melatonin intake on biological adaptations and anthropometric status in postmenopausal women: Randomized controlled trial.","authors":"Amel Bayoudh, Sonda Jallouli, Anis Kamoun, Henda Chahed, Hassan Bouzidi, Omar Hammouda","doi":"10.1016/j.exger.2026.113354","DOIUrl":"https://doi.org/10.1016/j.exger.2026.113354","url":null,"abstract":"<p><strong>Aim: </strong>Investigating the effectiveness of 12-week concurrent training associated with nocturnal melatonin supplementation on biological and anthropometric data in postmenopausal women (PMW).</p><p><strong>Methods: </strong>Thirty-eight PMW were randomly allocated to three groups: concurrent training (3 sessions/week) associated with melatonin (CTM, n = 13) or placebo (CTP: n = 13) (3 mg/night), and control group (C, n = 12). Biochemical and hematological parameters, body composition, waist (WC) and hip (HC) circumferences were assessed pre(T0)- and post(T1)-intervention.</p><p><strong>Results: </strong>Alanine aminotransferase, creatine kinase (CK), alkaline phosphatase, glucose, total cholesterol (p < 0.05), aspartate aminotransferase, low-density lipoprotein cholesterol (LDL-C) (p < 0.01) decreased while high-density lipoprotein cholesterol (p < 0.001) increased in CTM group compared with C group at T1 and over time only in CTM group (all: p ≤ 0.001 except glucose, total cholesterol: p < 0.01, LDL-C: p < 0.05). Comparatively with CTP, triglycerides (p < 0.05) and LDL-C (p < 0.01) decreased in CTM group at T1. In CTP group, CK (p < 0.05) decreased and phosphorus (p < 0.001) increased over time. Only in CTM group, leukocytes and urea (p < 0.05) decreased while mineral salts (all: p ≤ 0.01 except phosphorus: p < 0.001) increased over time. Fat mass, WC and HC decreased, while muscle mass (MM) increased over time in CTM (all: p < 0.001) and CTP (all: p ≤ 0.001 except WC: p < 0.01 and MM: p < 0.05) groups.</p><p><strong>Conclusion: </strong>Concurrent training associated with melatonin supplementation was beneficial for metabolic profile, cellular damage, selected renal and inflammatory biomarkers, mineral salts, and anthropometric status in PMW. This combined intervention was also more effective than training alone in improving lipid profile (LDL-C and triglycerides). Training alone had benefits on anthropometric data, CK and phosphorus levels.</p>","PeriodicalId":94003,"journal":{"name":"Experimental gerontology","volume":" ","pages":"113354"},"PeriodicalIF":4.3,"publicationDate":"2026-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149170740","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Infectious diseases and sarcopenia-related phenotypes: A phenome-wide Mendelian randomization study with exploratory proteomic analysis.","authors":"Ang Li, Yongqian Fan","doi":"10.1016/j.exger.2026.113341","DOIUrl":"https://doi.org/10.1016/j.exger.2026.113341","url":null,"abstract":"<p><p>Sarcopenia-related traits may be associated with infection-related disease liabilities, but broad phenome-wide genetic screening remains limited. We conducted a two-sample MR-PheWAS of more than 2000 FinnGen R12 phenome-wide endpoints against appendicular lean mass (ALM) and left-hand grip strength (HGS). Multiple testing was controlled using Benjamini-Hochberg false discovery rate (BH-FDR) correction applied separately to 2317 ALM and 2307 HGS primary-estimator tests. Twenty-one ALM endpoints and two HGS endpoints were FDR-significant; the two HGS endpoints were height and weight quantitative traits, and no disease phenotype or infection-related phenotype was FDR-significant for HGS. Among the FDR-significant ALM endpoints, four were infection-related. Rickettsioses were supported by a single instrument and were reported separately, whereas three multi-instrument phenotypes were prioritized for detailed follow-up: postzoster neuralgia, tonsillitis, and sequelae of tuberculosis. On the normalized ALM scale, postzoster neuralgia was associated with higher ALM (IVW beta = 0.01217, P = 1.17 × 10^-4), whereas tonsillitis (beta = -0.02580, P = 1.91 × 10^-4) and sequelae of tuberculosis (beta = -0.01247, P = 2.15 × 10^-4) were associated with lower ALM. Candidate-specific HGS analyses and reverse MR did not show statistically significant associations for these three phenotypes. An exploratory ALM-HGS intersection identified 23 nominally associated disease phenotypes, including five infection-related phenotypes. Exploratory proteomic analyses identified candidate proteins and pathways but did not establish mediation. Overall, the findings indicate phenotype-specific heterogeneity in genetic associations with muscle-related traits and require independent replication.</p>","PeriodicalId":94003,"journal":{"name":"Experimental gerontology","volume":" ","pages":"113341"},"PeriodicalIF":4.3,"publicationDate":"2026-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149083269","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of body composition on age- and sex-related differences in resting metabolic rate from a healthy aging cohort","authors":"Marcos Moliné ,&nbsp;Stephanie R. Heimler ,&nbsp;Jaclyn Bergstrom ,&nbsp;Lina Scandalis ,&nbsp;David Wing ,&nbsp;Daniel Moreno ,&nbsp;Howard J. Phang ,&nbsp;Anthony J.A. Molina","doi":"10.1016/j.exger.2026.113084","DOIUrl":"10.1016/j.exger.2026.113084","url":null,"abstract":"<div><div>Resting metabolic rate (RMR) accounts for the majority of the total energy expenditure. While RMR is known to decline with advancing age and is recognized to be lower in females compared to males, the mechanisms underlying these differences remain unclear. Changes in body composition are posited to account for age- and sex-related differences in RMR, but to what extent lacks consensus. We characterized 80 healthy adults aged 23–82 years from the San Diego Nathan Shock Center (SD-NSC) clinical cohort for body composition and RMR using dual-energy x-ray absorptiometry (DXA) and indirect calorimetry techniques, respectively. Body composition metrics—body surface area (BSA), lean tissue mass (LTM), and total body fat (TBF)—were modelled as predictive variables to assess their explanatory power against the age and sex effects on RMR. We found that the negative association between RMR and age persists even after adjusting for body composition and sex, with a predicted decrease in RMR per decade of 62.6 kcal/day (ꞵ = −62.6, <em>P</em> &lt; 0.0001). While individual body composition metrics do not account for the observed sex differences in RMR, adjusting for all body composition metrics together explained the observation that females have lower RMR compared to males. Our results suggest that while differences in body composition can explain sex differences in RMR, additional factors independent of body composition contribute to age-related differences. These results provide new insights into RMR differences among healthy individuals across the human life-course, which may inform age-appropriate interventions for optimizing metabolism.</div></div>","PeriodicalId":94003,"journal":{"name":"Experimental gerontology","volume":"217 ","pages":"Article 113084"},"PeriodicalIF":4.3,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147319114","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Changes in human multifidus muscle size with aging and short-term disuse","authors":"Fabio Sarto ,&nbsp;Elena Monti ,&nbsp;Sara Tagliaferri ,&nbsp;Bostjan Simunič ,&nbsp;Marco Salvi ,&nbsp;Tereza Jandova ,&nbsp;Martino V. Franchi ,&nbsp;Rado Pišot ,&nbsp;Marcello Maggio ,&nbsp;Marco V. Narici","doi":"10.1016/j.exger.2026.113090","DOIUrl":"10.1016/j.exger.2026.113090","url":null,"abstract":"<div><div>Lumbar multifidus (MF) muscle plays a key role in spinal stability, yet its adaptations to aging and disuse, which become increasingly prevalent with advancing age, remain unclear. We conducted two studies to investigate age- and inactivity-induced changes in MF size. In Study 1, we assessed 32 young adults (50% females) and 75 older adults (67% females), categorized as non-sarcopenic (NS) or probable sarcopenic (PS) based on EWGSOP2 criteria. In Study 2, we examined early MF responses to 10-day horizontal bed rest in 10 young males. MF cross-sectional area (CSA) and side-to-side asymmetry were measured using ultrasound imaging and compared with the vastus lateralis (VL) CSA. In Study 1, MF CSA was negatively associated with age (<em>p</em> &lt; 0.0001) and probable sarcopenia, being lower in PS compared to NS (<em>p</em> = 0.012). MF showed larger effect sizes than VL [Y vs NS: MF g = 1.62, VL g = 1.35; Y vs PS: MF g = 2.48, VL g = 1.35]. MF asymmetry was greater in PS compared to Y (<em>p</em> = 0.003). In Study 2, bed rest induced early reductions in MF CSA (detectable by day 4, <em>p</em> = 0.047) without increasing asymmetry. In conclusion, the MF was smaller in older populations and decreased following short-term disuse, while greater asymmetry was observed only with aging. These findings suggest that the MF is a highly plastic muscle in response to aging and disuse and that its assessment may serve as a potential hallmark of muscle maladaptation in clinical and experimental settings.</div></div>","PeriodicalId":94003,"journal":{"name":"Experimental gerontology","volume":"217 ","pages":"Article 113090"},"PeriodicalIF":4.3,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147388389","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}