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Experimental Gerontology

Elsevier BV

Preprints posted in the last 7 days, ranked by how well they match Experimental Gerontology's content profile, based on 11 papers previously published here. The average preprint has a 0.01% match score for this journal, so anything above that is already an above-average fit.

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A Lasting Legacy: Long-Term Effects of Exercise Training on Cardiometabolic Health in the STRRIDE-Prediabetes Reunion Study

Ross, L. M.; Sudnick, A. M.; Collins-Bennett, K. A.; Bo, N.; Counts, J. D.; Johnson, J. L.; Bennett, W. C.; Saldana, A. A.; Kennedy, K. G.; Aliferis, C. F.; Ma, S.; Huffman, K. M.; Peskoe, S. B.; Kraus, W. E.

2026-05-28 cardiovascular medicine 10.64898/2026.05.26.26352907 medRxiv
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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.

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Malnutrition and healthcare costs in older adults in Sweden: a longitudinal study based on a population-based cohort and Swedish registers

Xia, X.; Balcha, Y. M.; Carballo-Casla, A.; Aho, E.; Willers, C.; Rydwik, E.; Calderon-Larranaga, A.; Kugelberg, S.; Berggreen-Clausen, A.; Garpsater, J.; Jonsson, L.

2026-06-01 health economics 10.64898/2026.05.29.26354412 medRxiv
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Background The study aimed to estimate healthcare costs associated with malnutrition in Swedish older adults. Methods We conducted a cohort study using data from the population-based Swedish National Study on Aging and Care in Kungsholmen (SNAC-K, N = 2982), a geriatric inpatient cohort of complex patients (N = 7680), and a cohort of individuals with cognitive impairment from the Swedish Register of Cognitive/Dementia Disorders (SveDem, N = 64192). At risk of malnutrition and malnutrition were ascertained by the Mini-Nutritional Assessment in SNAC-K and the geriatric inpatient cohort. In SveDem, body mass index was used for identifying malnutrition. Healthcare resource use was derived from regional and national registers. Associations between malnutrition and healthcare costs in 2024 Swedish kronor (SEK) were analyzed using two-part models and generalized linear regression models, adjusting for demographic and clinical factors. Findings In the community, at risk of malnutrition and malnutrition were associated with an increase in annual healthcare costs of 2267 SEK (95% CI: 64,4469) and 1846 SEK (95% CI: -6802,10493), respectively. In geriatric patients, healthcare costs over 6 months in individuals at risk of malnutrition and individuals with malnutrition were 60205 SEK (45613,74798) and 86619 SEK (68362,104875) higher than those without malnutrition. In people with cognitive impairment, malnutrition was associated with higher annual healthcare costs (22170 SEK, 95% CI: 15152,29188). Interpretation Both at risk of malnutrition and malnutrition are associated with higher healthcare costs in Swedish older adults. The study findings are important for informing future economic evaluations of malnutrition interventions in Swedish older adults.

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Evaluating the sensitivity of heart rate variability fractal correlation properties to training load variations: Implications for monitoring training readiness and durability

van Rassel, C. R.; Rummel, M.; MacInnis, M. J.

2026-05-30 sports medicine 10.64898/2026.05.27.26354281 medRxiv
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This study examined the utility of HRV detrended fluctuation analysis alpha-1 (DFA1) to assess readiness-to-train and exercise durability under varying acute training loads. Nineteen trained cyclists completed two 20-minute time-trials (TT) under rested and fatigued conditions. DFA1 was measured during a standardized warm-up (WU), 20-min TT, and standardized cool-down (CD). Power output (PO) and DFA1 responses were compared across conditions, and associations with performance and fitness (W/kg) were examined. DFA1 values declined with increasing WU and CD exercise intensity (p<0.001) and were significantly attenuated following the 20-min TT (p<0.001). While DFA1 profiles did not differ significantly between rested and fatigued conditions, lower pre-TT DFA1 was associated with reduced TT performance (p=0.022; r=0.55), suggesting relevance to training readiness. Additionally, an 18% decline in DFA1 between 10- and 20-min during the TT (p=0.031), and lower post-TT values at matched intensities were observed (p<0.001), indicating physiological perturbation from the 20-min TT. Fitter participants exhibited lower DFA1 values during the 20-min TT (p<0.001; r=-0.77), suggesting a greater capacity to sustain physiological stress. While DFA1 is responsive to exercise intensity and stress, offering potential to assess training readiness and durability, more robust fatigue protocols are needed to validate DFA1 as training load monitoring tool.

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Contributions of immune cell biomarkers to explaining differences in mortality risk by sex in the Health and Retirement Study

Yin, M. A.; Nguyen, V.; Nathan, A.; Patel, C.

2026-05-29 epidemiology 10.64898/2026.05.27.26354256 medRxiv
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Background: It is well-established that males have a higher mortality risk than females. Immune cells and their function are known to undergo characteristic changes during aging, and immune cells are known to have sex differences. Immune cells and their function have been linked to mortality risk, but no studies have investigated to what degree, if at all, Immune Cell Biomarkers (ICBs) contribute to the known differences in mortality risk by sex. Methods: Using participant data from the Health and Retirement Study (n = 8,822), we applied multivariable linear regressions adjusting for age, cytomegalovirus (CMV) serostatus, sex, and race/ethnicity to identify differences by sex in 48 immune cell biomarker (ICB, e.g. T cells, B cells, Monocytes, etc.) percentages and counts (measured in 2016). We studied how the associations between ICBs and mortality risk differ by sex using stratified Cox Proportional Hazard (CPH) models. We estimated how inclusion of sex explained the relationship between ICBs and all-cause mortality, and conversely, how inclusion of individual and all ICBs combined explain the relationship between sex and all-cause mortality using multivariable modeling approaches. Results: Differences in ICBs by sex range between 2-38% (39/48 statistically significant). 9 ICBs were significantly associated with mortality risk in the entire sample. While different ICBs were significantly associated with mortality risk in the stratified analyses, particularly with respect to monocyte, B cell, and NK cell populations, adjusting for sex modestly influenced the hazard ratios of the ICBs (sex: 8 ICBs, percent change <5.4%). Furthermore, individual and cumulative contributions of ICBs in explaining the differences in mortality risk by sex were not significant.

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24-hour sleep-wake regularity and cognitive aging among 74,733 middle-aged and older adults from the US and Europe: The LifeSPAN Consortium

Hoepel, S. J. W.; Albrecht, A.; Chen, J.; Cribb, L.; Danilevicz, I. M.; Buchman, A. S.; Barnes, L. L.; Bennett, D. A.; Bertisch, S. M.; Burns, A. C.; Hughes, T. M.; Ancoli-Israel, S.; Lim, A.; Luik, A. I.; Purcell, S. M.; Redline, S.; Stone, K. L.; Wolters, F. J.; Xiao, Q.; Yaffe, K.; Yiallourou, S.; Wallace, M. L.; Li, P.; Sabia, S.; Pase, M. P.; Leng, Y.

2026-06-01 epidemiology 10.64898/2026.05.22.26353492 medRxiv
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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.

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Association Between Quadriceps Strength And Knee Flexion During Drop Landing In Healthy Adolescent Athletes

Lyons, B.; Hopfauf, J.; Bond, C. W.; Noonan, B. C.

2026-05-30 sports medicine 10.64898/2026.05.28.26353494 medRxiv
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Background: Quadriceps strength and landing mechanics are two modifiable factors associated with anterior cruciate ligament (ACL) injury risk. Collecting detailed biomechanical data is an arduous task. Identifying a relationship using more easily measured variables, such as quadriceps strength, would offer value for athlete counseling and injury prevention programs. Although quadriceps weakness has been associated with altered landing strategies in ACL-reconstructed (ACLR) individuals, this relationship is less clear in healthy athletes. Purpose: To investigate the association between isokinetic quadriceps strength and peak knee flexion angle during a vertical drop jump in healthy adolescent athletes. Study Design: Secondary analysis of previously collected data. Methods: Healthy adolescent athletes had their dominant leg quadriceps strength measured using an isokinetic dynamometer at 60{degrees}/s from 0-90{degrees} of knee flexion. Landing mechanics were assessed during a vertical drop jump using three-dimensional motion capture synchronized with force plates. Pearson correlation was used to evaluate the association between quadriceps strength and peak knee flexion angle during landing, with statistical significance defined as p < .05. Results: There was a weak negative correlation between quadriceps strength and peak knee flexion angle (p = .017, R = -.22 [-.04, -.38]), suggesting that stronger athletes achieved greater knee flexion angles. Discussion: Greater quadriceps strength was associated with increased peak knee flexion angles during landing; however, the weak correlation suggests that strength explains only a small portion of the variability in landing mechanics. These findings deviate slightly from prior literature in healthy populations but are consistent with studies demonstrating that greater quadriceps strength is associated with achieving greater peak knee flexion in ACLR patients. Accordingly, quadriceps strengthening should remain a key component of multifactorial ACL injury prevention programs.

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DNA Methylation Signatures of Atherosclerosis and Vascular-Related Outcomes in U.S. and Irish Population-Based Cohorts

Ammous, F.; Smith, T.; Scarlett, S.; Hernandez, B.; McCrory, C.; Kenny, R. A.; Mitchell, C.; Faul, J. D.

2026-05-27 epidemiology 10.64898/2026.05.25.26354072 medRxiv
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Atherosclerosis is a systemic vascular process linked to cardiovascular, cognitive and renal outcomes. DNA methylation (DNAm)-based scores of atherosclerosis may capture cumulative biological processes underlying vascular aging. Here, we examined associations of DNAm scores for coronary artery calcification (DNAm-CAC) and carotid plaque (DNAm-cPlaque), derived from a large study of imaging-based subclinical atherosclerosis, with prevalent and incident outcomes in two population-based cohorts of older adults: the Health and Retirement Study (HRS; n = 3,875) and The Irish Longitudinal Study on Ageing (TILDA; n = 487). Higher DNAm scores were associated with adverse cardiometabolic profiles and socioeconomic indicators. In HRS, higher DNAm-CAC was associated with prevalent cardiovascular disease (odds ratio per SD, 1.16; 95% confidence interval (CI), 1.07-1.26), lower cognitive function ({beta} = -0.50, 95% CI -0.68 to -0.32) and lower estimated glomerular filtration rate (eGFR; -1.7 ml min-1 1.73 m-2, 95% CI -2.6 to -0.8) in unadjusted models. After adjustment for demographic and clinical risk factors, DNAm-CAC ({beta} = -0.29, 95% CI -0.46 to -0.13) and DNAm-cPlaque ({beta} = -0.24, 95% CI -0.42 to -0.06) remained associated with lower cognitive function, and DNAm-cPlaque was associated with incident cognitive impairment or dementia (hazard ratio per SD, 1.16; 95% CI, 1.01-1.32). Associations were attenuated after further adjustment for race/ethnicity and socioeconomic indicators. In TILDA, higher DNAm-cPlaque was associated with worse cognitive performance (incidence rate ratio, 1.11; 95% CI, 1.01-1.21), increased risk of incident cardiovascular disease (hazard ratio, 1.18; 95% CI, 1.00-1.42) and lower eGFR, with consistent associations observed for DNAm-CAC. These findings suggest that DNAm-based scores of atherosclerosis capture systemic vascular processes linked to multiple age-related outcomes across populations. Further work is needed to clarify the biological pathways reflected by these scores and their relation to cumulative and socially patterned vascular risk.

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Loss of a Spouse and Risk of Cognitive Decline: Insights from Six Prospective Cohort Studies

Guo, C.; Wang, Y.; Sun, X.; Ge, F.

2026-06-01 psychiatry and clinical psychology 10.64898/2026.05.20.26353668 medRxiv
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Aims. The risk of cognitive decline after losing a spouse remained mixed. This study aims to investigate the association between spousal loss and risk of cognitive decline, assess whether this association varies by sex and age, and identify modifiable factors. Methods. We conducted a prospective cohort study using harmonized data from six population-based aging surveys: the US Health and Retirement Study and its sister surveys in England, Mexico, China, India, and South Africa, incorporating their respective Harmonized Cognitive Assessment Protocol (HCAP) sub-studies. Spousal loss (yes vs no) was the exposure. Cognitive outcomes (i.e., orientation, memory, executive function, and language), were assessed using HCAP neuropsychological batteries. We conducted parallel analyses in six cohorts. Associations between spousal loss and cognitive outcomes were estimated using generalized linear models, and summarised estimates were derived via random-effects meta-analyses. Sex stratification and restricted cubic spines were used to examine how these associations vary by sex and age, respectively. Results. The analytical cohort consisted of 18,551 individuals aged 61.22 (SD 6.30) to 71.37 (SD 7.33) years. Widowhood prevalence ranged from 14.1% in CHARLS to 53.9% in HAALSI and was consistently higher in women. Spousal loss was associated with poorer memory (multivariable-adjusted {beta} = -0.07, 95% CI -0.12 to -0.01) and executive function (multivariable-adjusted {beta} = -0.08, 95% CI -0.13 to -0.03) in the meta-analysis, with no significant associations for orientation or language. While results were generally consistent in five cohorts, the ELSA showed divergent patterns (orientation: {beta} = 0.10, 95% CI 0.06 to 0.13; memory: {beta} = 0.05, 95% CI 0.02 to 0.08; language: {beta} = 0.16, 95% CI 0.12 to 0.19). Sex-stratified analyses indicated poorer executive function among men (multivariable-adjusted {beta} = -0.14, 95% CI -0.19 to -0.08) and poorer memory among women (multivariable-adjusted {beta} = -0.07, 95% CI -0.14 to -0.01) following widowhood. Nonlinear age-related effects on cognition were observed in ELSA, LASI, and HAALSI. Higher education, internet use, and BMI were negatively associated with the risk of cognitive decline among widowed participants. Conclusions. Spousal loss is associated with domain- and sex-specific differences in cognitive performance, with substantial heterogeneity across study populations. Future research should integrate biopsychosocial markers to develop context-sensitive interventions for widowed older adults.

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Sleep Disorders Modify the Age-Related Trajectory of Circadian Rest-Activity Rhythms: Evidence from NHANES 2011--2012 Wrist Actigraphy

Yin, L.; Lee, C. W.; Wong, A.

2026-06-01 epidemiology 10.64898/2026.05.28.26354369 medRxiv
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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.

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Health Literacy and Lifestyle Scores Among A Small but Diverse Group of Older Asian Adults Who Attended Community Health Events in Los Angeles

Zhang, E.; Tran, T.; Shun, K.; Tran, D.; Tsai, A.; Kwang, E.; DerSarkissian, M.; Kuo, T.

2026-05-29 epidemiology 10.64898/2026.05.27.26354181 medRxiv
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The Asian population in Los Angeles is among the largest and most heterogeneous in the U.S. This is true culturally and health-wise. Older Asians have differing risks for cardiovascular and cardiometabolic disease, depending on their ethnicity, health literacy, and lifestyle choices. This pilot examines several of these factors in a small but diverse group of older Asian adults who attended community health events from 2024-2025. Self-reported and biometric data were collected at five such events hosted by the Asian Pacific Health Corps at UCLA. The pilot generated health literacy and lifestyle (HLL) scores for all participating attendees and explored how they relate to their socio-demographics, healthcare habits, and predictions of their own health data. Overall, there were significantly more females than males with higher HLL scores (p = 0.027). College education (p = 0.028) and "normal" ranges for biometric data (e.g., blood pressure, BMI, blood glucose, cholesterol) were related to higher median HLL scores. With a few exceptions, fewer than 50% accurately predicted their biometric numbers regardless of HLL scores, suggesting a disconnect between perception and reality, and that better provider-patient communication may help foster greater patient understanding about their chronic conditions. These HLL score distributions indicate that educational attainment, better awareness of one's health, and high health literacy are individual factors that may influence older Asians' understanding and potential approach to managing their health conditions.

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Comparison of Mechanical Tissue Properties Using MyotonPRO and Time-Harmonic Elastography: Understanding Fundamental Differences and Statistical Relationships

Kurz, E.; Valli, G.; Meyer, T.; Proger, S.; Schwesig, R.; Bartels, T.; Delank, K.-S.; Sack, I.; Aghamiry, H. S.

2026-05-28 sports medicine 10.64898/2026.05.20.26353658 medRxiv
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Abstract Purpose: MyotonPRO (MTP) and time-harmonic elastography (THE) are increasingly used to assess muscle mechanical properties, yet they operate on fundamentally different physical principles. MTP measures composite MTP stiffness (N/m) through surface oscillations, while THE quantifies intrinsic shear modulus (THE stiffness, kPa) via propagating shear waves. This study aimed at systematically compare MTP and THE measurements in the vastus lateralis muscle across different contraction intensities and examine how the skin layer and subcutaneous fat (SLSF) thickness influence their relationship. Methods: Twenty-six healthy adults (15 males, 11 females; age 25 [SD 4] years) underwent MTP and THE measurements of the vastus lateralis at rest and during isometric contractions at 15% and 30% maximal voluntary contraction (MVC). Effects of contraction intensities on tissue properties were assessed using univariate analyses of variance with repeated measures. Associations between the different outcomes of THE and MTP technologies were explored using Pearson's correlations and partial correlation coefficients separately for each contraction intensity with adjustment of the SLSF thickness of participants. Results: Both technologies detected contraction intensity-dependent stiffening across all outcomes (p < 0.001). THE stiffness increased from 5.3 [1.2] kPa at rest to 15.6 [6.1] kPa at 30% MVC; THE wave attenuation increased from 0.83 [0.19] to 1.42 [0.36] s/m while MTP stiffness increased from 337.3 [49.3] N/m at rest to 529.4 [160.7] N/m at 30% MVC. Correlations between modalities were weak and condition-dependent. THE wave attenuation did not significantly correlate with any MTP outcome across conditions. Conclusion: MTP and THE detect contraction-induced stiffening through fundamentally different physical mechanisms and should not be regarded as interchangeable. Their correlation is modest at rest and breaks down (or reverses) during active contraction, with subcutaneous fat as a key modifying factor. Clinical trial number: Not applicable.

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Acute effect of high-intensity interval training on fetal blood flow distribution

Skarstad, H. M. S.; Skrede, S.; La Haganes, K.; Ashby, E. R.; Sujan, M. A. J.; Deibele, K. U.; Morch, H.; Haugen, G. N.; Salvesen, K. A.; Moholdt, T.

2026-05-28 sports medicine 10.64898/2026.05.27.26354197 medRxiv
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Objectives To examine the acute effects of a single bout of high-intensity interval training (HIIT) on fetal blood flow distribution during the third trimester of pregnancy. Methods Thirty-four healthy pregnant participants (mean age 31.6 years, standard deviation (SD) 4.1; gestational week 33.8 (SD 0.4) completed eight 30-second high-intensity cycling work-bouts interspersed with 2-minute rest periods. Fetal heart rate (FHR), maternal blood pressure, and Doppler-derived blood flow indices in the middle cerebral artery, umbilical artery and vein, and ductus venosus were assessed before and after exercise. We estimated fetal liver blood flow and the ratio of umbilical vein flow to ductus venosus. Maternal heart rate (HR) and FHR were recorded throughout exercise. Paired t-tests compared pre- and post-exercise values. Results No significant changes were observed in fetal blood flow indices or distribution following exercise. Average maternal HR and FHR during the work-bouts were 158 bpm (SD 16) and 152 bpm (SD 12), respectively. Following HIIT, maternal systolic blood pressure increased by 5 mmHg (95% CI 1 to 8, p=.014), maternal HR by 22 bpm (95% CI 15 to 28, p<.001), and FHR by 13 bpm (95% CI 10 to 17, p<.001). We recorded 16 instances of FHR above normal range during HIIT. Conclusion A single HIIT session in late pregnancy increased maternal blood pressure and HR and transiently elevated FHR but did not affect fetal blood flow indices or distribution. Brief episodes of fetal tachycardia were observed but appeared to be clinically insignificant. Future research should investigate the effects of repeated HIIT exposure during pregnancy.

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Associations between serum estradiol and estrone and Alzheimer's disease biomarkers: an analysis in female participants from the European Prevention of Alzheimer's Dementia Longitudinal Cohort Study (EPAD LCS)

Shin, J.; Muniz-Terrera, G.; Ritchie, C.; Manson, J.; Plachecki, S.; Kirschbaum, C.; Gregory, S.

2026-05-30 epidemiology 10.64898/2026.05.27.26354257 medRxiv
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INTRODUCTION: Postmenopausal estrogen decline may contribute to Alzheimer's disease (AD) risk, but longitudinal evidence linking circulating estrogens to cerebrospinal fluid (CSF) biomarkers is lacking. METHODS: We analyzed 866 female participants from the European Prevention of AD Longitudinal Cohort Study with baseline serum estradiol and estrone measured by liquid chromatography tandem mass spectrometry and repeated CSF measurements of amyloid-beta (A{beta})42, phosphorylated (p) Tau181, and total (t) Tau. RESULTS: Neither estradiol nor estrone was associated with longitudinal A{beta}42. Higher estradiol was associated with lower baseline tau and slower tau increases over time. Baseline estradiol-tau associations were stronger in apolipoprotein E (APOE) {epsilon}4 carriers, though APOE{epsilon}4 did not modify longitudinal associations. Amyloid positivity did not moderate hormone-tau associations but was associated with steeper tau increases over time. Estrone showed no significant associations. DISCUSSION: These findings suggest a more consistent relationship between estradiol and tau-related rather than amyloid-related pathology.

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Linking School Stress and Psychosomatic Complaints in South Tyrol, Northern Italy: Parental and adolescents perspectives in a cross-sectional design

Barbieri, V.; Piccoliori, G.; Engl, A.; von Strobele Prainsack, D. H.; Wiedermann, C. J.

2026-05-30 public and global health 10.64898/2026.05.26.26354140 medRxiv
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Background School stress and psychosomatic complaints are linked and increase in high-income countries, with differences between countries. Evidence of how these parameters develop in Italy, particularly through combined parental and self-reported perspectives across age and gender, is limited. Methods A population-based online survey investigated school stress and psychosomatic complaints in children and adolescents aged 6-19 years, analyzing proxy- and self-reported data based on standardized validated instruments. Data was stratified by gender and age for children (6-10), early adolescents (11-14), and late adolescents (15-19). Results For early and late adolescents, the gender gap was evident, with higher levels of stress and health complaints in late adolescent girls. In this group, 56% of the girls self-reported rather/high school stress, and 43% of the boys. Parents perceived school stress and psychosomatic problems of their children as less severe than adolescents themselves. Parents stated a higher effect of parental help with school problems, and a lower effect of physical activity and digital media use on their childrens psychosomatic problems. Physical activity was related to fewer psychosomatic complaints, especially in girls. Conclusions This study identified late adolescent girls as vulnerable group, underscoring the critical need for gender-specific early prevention strategies starting in childhood, particularly for families with lower socioeconomic status. Parental perspectives may underestimate adolescents stress levels and psychosomatic well-being. In early adolescence, less digital media use may prevent psychosomatic problems, in late adolescence, physical activity may be a preventive method. Further longitudinal investigations should put a special focus on self- and proxy-reported perspectives.

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Keeping human in the loop: A three-phase generative AI workflow for research integrity in data-intensive science.A methodological case study using elite Ethiopian distance-running data

Galko, P.; Yisamaw, A.; Haugen, T.; Seiler, S.

2026-05-29 sports medicine 10.64898/2026.05.29.26354013 medRxiv
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Background: Generative AI tools can support data-intensive research by writing code, drafting prose, searching analytical possibilities, and stress-testing claims. They can also produce false citations, drift between statistical specifications, and lose continuity across long investigations. This paper describes a practical workflow for using AI systems in empirical research while keeping discovery, verification, and accountability inspectable. Methods: We developed and applied a three-phase human-AI workflow to a case study of 14 elite Ethiopian distance runners. The dataset contained 22,605 GPS-segments collected across 97 consecutive days in late 2025, supplemented by venue and athlete metadata collected in the field. Phase 1 used an autonomous data-exploration tool to pre-filter the hypothesis space across five seeded research questions. Phase 2 used an AI system under direct human guidance to construct candidate findings into numerical claims, verification scripts, and draft text. Phase 3 used an independent AI system in an adversarial role to stress-test methods, statistics, prose, figures, and citations. The workflow was informed by Pearl's distinction between association, intervention, and counterfactual reasoning, with human judgement retained for research direction, interpretation, and final claims. Results: The workflow produced three empirical analyses and a documented correction process. The analyses estimated an altitude-to-sea-level pace correction of +0.10 min/km per 1,000 m at matched heart rate, showed why pooled altitude-surface regression was not identifiable within this venue system, documented method-dependence in heart-rate-based intensity classification, characterised within-venue route variation as a 64/36 path-fixed-to-trail-variable split with the Sululta label resolving into two functionally distinct sub-venues, and reframed the cohort's training through a 3x3x3 prescription lattice grounded in Ethiopian coaching practice. The adversarial phase identified several hallucinated citations, a terminology error between HC1 and cluster-robust standard errors, and several inconsistencies between prose, figures, and computed results. Verification scripts re-derived nearly all numerical claims from the cleaned lap-level data. Conclusions: The case study shows how researchers can organise AI-assisted empirical work so that candidate discovery, claim construction, independent stress-testing, and final accountability remain separated. The workflow did not remove the need for domain expertise or human judgement. Its value was in making the route from candidate finding to manuscript claim explicit, reproducible, and open to challenge. Trial registration: Not applicable.

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A Bibliometric and Content Analysis of Exercise Interventions Research in Rheumatoid Arthritis

Zou, Z.; Zhang, Z.; Zhao, R.; Liu, Y.; Gao, J.; Gu, L.

2026-05-28 rheumatology 10.64898/2026.05.27.26354187 medRxiv
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Background: Rheumatoid arthritis is a chronic inflammatory disorder in which exercise is increasingly recognized as an important component of long-term management. Yet, most reviews in this field evaluate the effects of single exercise modalities, while bibliometric studies primarily identify publication trends and research hotspots without showing whether highly visible themes also represent coherent and comparatively mature evidence domains. Methods: We searched the Web of Science Core Collection for publications on exercise interventions in rheumatoid arthritis from 2016 to 2025. CiteSpace (6.4.1) and VOSviewer (1.6.20) were used to analyze publication growth, collaboration networks, keyword co-occurrence, thematic clusters, and burst terms. We then applied structured content coding in Excel 2021 to classify exercise modalities, outcome domains, and mechanistic topics, and integrated these findings into a visual evidence-distribution profile. Results: Publication output increased from 16 studies in 2016 to 37 in 2025. The United States led in productivity, Karolinska Institutet was the most prolific institution, and Kitas, Duda, and Metsios were among the most influential authors. Keyword analyses identified a shift from function- and disease-focused themes toward quality of life, risk factors, and comprehensive management. The integrated analysis revealed an uneven evidence structure: aerobic and resistance training accounted for the most concentrated and recurrently studied exercise-outcome domains, whereas mind-body and water-based interventions formed visible but methodologically heterogeneous clusters. Newer modalities, including blood flow restriction training and high-intensity interval training, showed growing prominence but limited depth of evidence. Conclusion:Exercise research in rheumatoid arthritis has evolved toward broader and more patient-centered management targets, but the field remains imbalanced across intervention types and outcome domains. This study demonstrates the value of combining bibliometric mapping with structured content analysis to distinguish thematic visibility from evidentiary coherence in heterogeneous intervention fields and may offer a transferable analytical framework for research evaluation beyond rheumatoid arthritis. Keywords: Rheumatoid Arthritis; Exercise Intervention; Bibliometrics; Content Analysis; Rehabilitation

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Biological Age and Complication Prediction in Hypertension: A 13-Year Cohort

Kim, B.-s.; Bae, C.-y.; Kim, I.-h.; Choi, Y.-j.; Jeon, M.-h.

2026-05-29 epidemiology 10.64898/2026.05.27.26354288 medRxiv
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1. Background: With the rising prevalence of hypertension, especially among younger populations, there is a critical need to better assess health status and predict associated complications. This study developed a biological age model ("hypertension age") for hypertensive patients to predict the risk and timing of major complications. 2. Methods: Using South Korea's NHIS-NHID data, researchers analyzed 4,535,041 hypertensive patients who underwent health examinations between 2009 and 2010. Patients were followed for an average of 12.40 years (until 2022). Principal Component Analysis (PCA) was used to develop the biological age (cBA) model. The risk and onset timing of complications were analyzed using Cox proportional hazards and multiple regression models, adjusting for variables like medication use and baseline diseases. 3. Results: A 1-standard deviation (SD) increase in the age gap?where biological age exceeds chronological age (cBA - CA)?was significantly associated with an elevated risk for all major complications in both sexes (p < 0.001). Furthermore, a 1-SD increase in this gap significantly accelerated the time to complication onset for nearly all conditions (p < 0.001), with the exception of dementia in women. The impacts of medication use, hypertension duration, and baseline comorbidities varied by specific complication. 4. Conclusions: Lowering "hypertension age" relative to chronological age can significantly reduce the risk and delay the onset of major cardiovascular and related complications. Quantifying this biological age gap serves as a powerful motivational tool for personalized health management and complication prevention in hypertensive patients.

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Centenarians and Oldest Olds in Liguria - COOL: a multidisciplinary study to investigate the genetic determinants of cognitive well-being in Genoa, Italy. Rationale, study protocol and cohort profile.

Di Maria, E.; Gualco, C.; Muscolino, E.; Reale, N.; Solaro, C. M.; Camia, L.; Tortorolo, U.; Ivaldi, C.; Mazzella, L.; Bandini, F.; Maioli, E.; Stella, M.; Mattioli, F.; Zumerle, E.; Flego, G.; Mazzocco, M.; Sacchi, N.; Schenone, A.; Tettamanti, M.; Marcon, G.; The COOL study Investigators, ; Del Sette, M.

2026-05-28 neurology 10.64898/2026.05.20.26353506 medRxiv
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Objectives. Despite the body of literature on genetic risk factors for dementia, little is known on protective genetic factors associated with favourable cognitive ageing in the oldest population. In Europe, Italy has a leading position with a swelling population of centenarians, and the urban area of Genoa in the Liguria region has one of the highest prevalence of centenarians. The COOL study is a not-for-profit, multicentric study involving a cohort of centenarians (aged >99) living in the Genoa area. The ultimate aim is the identification of genomic biomarkers associated with cognition in the oldest old population. Results. Participants underwent a semi-structured interview on personal, disease and family history, and a neuropsychological assessment of the main cognitive domains. As of July 2025, we enrolled 88 centenarians (age range: 99-108, median 100.56) with and without cognitive impairment; 32 subjects were followed up. All participants were of Italian ancestry, 81% were female. The cognitive profile in assessed subjects showed a wide range of cognitive health measures (CDR 0-5; MMSE 3-30, median 24). Whole peripheral blood and DNA samples from 67 participants were stored. Conclusions. We demonstrated that the protocol is feasible, and acceptable by participants and their families. A comprehensive phenotype dataset was established, and DNA samples were stored. Centenarians exhibited a broad spectrum of cognitive profiles, from preserved cognition to severe dementia. These findings will eventually allow to interpret the profiles of genomic variants as associated with variability of cognitive performance in centenarians. The molecular underpinnings of healthy cognitive ageing could inform health policy strategies in the general population.

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Dried blood spot proteomics as a diagnostic framework for citrin deficiency

Totsune, E.; Nakajima, D.; Konno, R.; Mikami-Saito, Y.; Arai-Ichinoi, N.; Nishida, H.; Yagi, H.; Ishige, T.; Suzuki, H.; Shirota, M.; Takayama, J.; Takano-Asai, C.; Shimura, M.; Sasai, H.; Lee, T.; Kido, J.; Nakajima, Y.; Kobayashi, H.; Kikuchi, A.; Numakura, C.; Hamazaki, T.; Oishi, K.; Nakamura, K.; Kawashima, Y.; Ohara, O.; Wada, Y.

2026-05-28 genetic and genomic medicine 10.64898/2026.05.26.26354012 medRxiv
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Background: Citrin deficiency, caused by biallelic pathogenic variants in SLC25A13, must be identified early to prevent serious complications such as hyperammonemia and liver failure. However, clinical diagnosis is often delayed due to its nonspecific presentation and limited sensitivity of amino acid-based newborn screening methods. Although genome-based evaluations are being investigated to address these issues, concerns about their cost, turnaround time, variant interpretation ability, and data handling highlight the need for a more practical yet reliable alternative. We investigated the feasibility of applying proteomic approach on dried blood spots (DBS), which are routinely used in newborn screening. Methods: We performed untargeted liquid chromatography-tandem mass spectrometry to analyze the proteome of DBS using a previously developed "non-targeted analysis of non-specifically DBS-absorbed proteins" (NANDA) workflow. SLC25A13 protein abundance was quantified in individuals with biallelic loss-of-function mutations, compound loss-of-function/missense mutations, and heterozygous carriers; this was also evaluated in healthy and diseased controls representing relevant differential diagnoses. To leverage proteomic information, we derived a multivariate proteomic signature using feature selection and evaluated its performance with leave-one-out cross-validation. Biological relevance was assessed by enrichment analysis, and complementary transcriptomics was performed using RNA sequencing. Results: A total of 7,474 proteins, including SLC25A13, were consistently detected in DBS. SLC25A13 was undetectable in individuals with biallelic loss-of-function mutations. However, individuals with compound loss-of-function/missense genotypes showed reduced but measurable SLC25A13 levels, comparable to those observed in heterozygous carriers. In contrast, a compact 15-protein signature accurately identified individuals with compound loss-of-function/missense genotypes (AUC, 0.99; sensitivity, 1.00; specificity, 0.95). The signature was enriched for Ca2+-response, and transcriptomics showed downregulation of genes related to multimodal ion channels in affected individuals compared to controls. Conclusions: DBS-based proteomic profiling may assist in the diagnosis of citrin deficiency through SLC25A13-quantification and a biologically plausible multivariate signature. More broadly, this strategy offers a promising new diagnostic layer for protein disorders, providing a proteomic readout in a clinically practical DBS format with potential utility for future diagnostic and screening applications.

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Small palpebral fissure as a significant risk factor for glaucoma surgery failure

Okuzumi, N.; Mori, S.; Katakami, K.; Iwaki, Y.; Sakamoto, M.; Yamada, Y.; Nakamura, M.

2026-05-28 ophthalmology 10.64898/2026.05.27.26354208 medRxiv
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Purpose: To evaluate the impact of ''not commonly considered risk factors '' on glaucoma surgical outcomes. Methods: This study included 339 eyes that underwent glaucoma surgery. Surgical procedures included microhook ab-interno trabeculotomy (TLO), Preserflo ab-externo microshunt implantation, trabeculectomy (Trab), and Ahmed Glaucoma Valve (AGV) implantation. In addition to conventional background factors, we examined a set of ''not commonly considered risk factors, '' including very elderly age ([&ge;]85 years), avitreous status, aphakia, use of antithrombotic agents, difficulty attending frequent postoperative visits, small palpebral fissure, corneal endothelial dysfunction, poor vision in the fellow eye, dementia, hearing loss, mental illness, atopic dermatitis, pseudophacodonesis, glaucoma eye drop allergy, and conditions contraindicating {beta}-blocker use. Surgical success was defined as intraocular pressure (IOP) [&le;]21 mmHg, [&ge;]20% reduction from baseline, and no additional glaucoma surgery at 1 year. Logistic regression was performed to identify potential risk factors; significant factors were further evaluated using propensity score matching. Results: Of the 339 cases, surgical success rates were 65% for TLO, 82% for Preserflo, 91% for Trab, and 82% for AGV. Multivariate logistic regression identified two independent predictors of surgical failure: small palpebral fissure (odds ratio 2.52, p < 0.01) and hearing loss (odds ratio 3.94, p = 0.04). Propensity score matching of patients with small versus large palpebral fissures (111 per group) confirmed significantly worse postoperative outcomes in the small-palpebral-fissure group despite balanced baseline characteristics. Conclusion: Small palpebral fissure is an independent and previously unnoticed risk factor for glaucoma surgical failure, affecting both minimally invasive and filtration procedures.