ECSS Paris 2023: OP-MH23
INTRODUCTION: Age-related declines in cardiorespiratory fitness are a key physiological hallmark of aging and are closely associated with reduced physical function and quality of life in older adults. Exercise training is widely recommended to promote healthy aging; however, its role in intervening in age-related physiological decline and the underlying mechanisms remain insufficiently understood. Peak oxygen uptake (VO2peak) is a central indicator of cardiorespiratory fitness and a potential mechanistic link between exercise training and functional health outcomes. This study examined whether improvements in VO2peak mediate the effects of exercise training on physical quality of life in older adults, providing longitudinal mechanistic evidence for exercise as an intervention targeting age-related functional decline. METHODS: Forty community-dwelling older adults were allocated to an exercise training group (n = 20) or a control group (n = 20). The exercise group completed 3 months of supervised combined aerobic and resistance training, while the control group maintained their usual lifestyle. VO2peak and health-related quality of life were assessed before and after the intervention, with the Physical Component Summary (PCS) score derived from the SF-36 questionnaire. Linear mixed-effects models were used to examine group-by-time interaction effects, with intervention effects evaluated after adjusting for age, sex, body mass index (BMI), and other relevant covariates. Pearson correlation analysis and causal mediation analysis based on changes (Delta) in VO2peak and PCS were subsequently conducted. Nonparametric bootstrap procedures with 5000 resamples were applied to estimate mediation effects and corresponding confidence intervals. RESULTS: Significant group-by-time interactions were found for VO2peak and PCS (p < 0.01), with greater improvements in the exercise group. Delta VO2peak was positively correlated with Delta PCS (r = 0.69, p < 0.001). Mediation analysis indicated that Delta VO2peak significantly mediated the effect of exercise on PCS (ACME = 2.92, 95% CI: 0.81-5.43, p = 0.008), accounting for approximately 39% of the total effect (total effect = 7.49, p < 0.001). The direct effect of exercise remained significant (ADE = 4.56, p = 0.004). CONCLUSION: Using a controlled longitudinal design, this study provides mechanistic evidence that exercise training can intervene in age-related functional decline by improving VO2peak, which in turn contributes to better physical quality of life in older adults. Beyond enhancing cardiorespiratory fitness levels, the findings suggest that structured exercise training may modify the age-related trajectory of cardiorespiratory fitness decline. VO2peak therefore represents not only a key outcome of exercise training, but also a modifiable physiological pathway through which exercise may influence functional aging.
Read CV Kexin DingECSS Paris 2023: OP-MH23
INTRODUCTION: Sleep disturbances are common among individuals with chronic primary low back pain (CPLBP), with 59% of them experiencing poor sleep quality (1). This study aimed to study the sequential effects of a two-phase multimodal intervention compared with a control group on sleep quality in individuals with CPLBP within the HEALTHYBACK randomized controlled trial (2). METHODS: Seventy participants with CPLBP were randomized; per-prtocol analysis included individuals attendeding ≥65% of sessiones (mean age 51.1 ± 10.8 years; 39 women): control group (CG, n=33), and multimodal intervention group (MG, n=23). The IG completed a 16-week two-phase intervention conducted in hospital setting. Phase I (8-week) comprosed supervised physical exercise (2 sessions/week, 45 min), mindfulness-based stress reduction (1 session/week, 2.5 h), pain neuroscience education (biweekly, 2.5 h) and daily behaviour change supported by a wrist-worn activity prompting device. Phase II (8 weeks) consisted of supervised functional full-body muscle strengthening exercise (3 sessions/week, 45 min). The CG maintained usual lifestyle habits. Sleep quality (0-21, higher scores represent poorer sleep quality) was assessed using the Pittsburgh Sleep Quality Index at baseline, after Phase I, and after Phase II. Within-group changes were examined using repeated-measures ANOVA. Between-group differences in change scores (post–pre and post2–pre) were analyzed using ANCOVA adjusted for baseline values. RESULTS: Within-group analyses showed significant improvements in sleep quality after Phase I (mean difference = −1.96; 95% CI −3.33 to −0.59, p=0.070) and demonstrated greater improvements following Phase II (−2.61; 95% CI −4.16 to −1.06, p=0.020) in the IG. No significant changes were observed in the CG across time points. Between-group analyses (ANCOVA on change scores) revealed significantly greater reductions in sleep quality in the IG compared with the CG after Phase I (adjusted mean difference in change = −1.90; 95% CI −3.65 to −0.15; p=0.034) and after Phase II (−1.76; 95% CI −3.37 to −0.15; p=0.033). CONCLUSION: A structured two-phase multimodal intervention, followed by moderate-to-high intensity functional full-body muscle strengthening exercise, significantly improved subjective sleep quality in individuals with CPLBP compared with usual care. These findings support the potential role of multidimensional exercise-based approaches in addressing sleep disturbances in this population. Future studies incorporating objective sleep assessments (e.g., actigraphy or polysomnography) are warranted to complement these results. REFERENCES: (1) Alsaadi SM, et al. Eur Spine J (2011) 20:737–743. doi 10.1007/s00586-010-1661-x (2) Tsiarleston G, et al. BMJ Open Sp Ex Med 2024;10:e002188. doi:10.1136/bmjsem-2024-002188 FUNDING: Instituto de Salud Carlos III (CP20/00178 and PI22/01791).
Read CV MILKANA MARIA BORGES COSICECSS Paris 2023: OP-MH23
INTRODUCTION: Vascular endothelial cells (ECs) influence hematopoiesis and atherogenic adaptations in disease. The extent to which ECs may influence hematopoiesis during exercise has not been investigated. Here, we show that ECs within the marrow may respond to exercise-induced increases in hemodynamic forces and may influence neighboring hematopoietic cells. METHODS: We initiated our experimentation by examining if bone marrow ECs experience increases in shear stress during exercise. Using a unilateral limb model, shear stress was modulated within the bone marrow vasculature using surgical femoral artery ligation in mice which partially abrogated blood flow into the tibia. Shear stress sensors were measured at the transcriptional level using qPCR. For human translation, we enumerated leukocyte egress into circulation within in a convenience sample of one asplenic and one splenic human during maximal exercise. Endothelial paracrine signalling was examined using cultured ECs that were exposed to shear stress or static conditions in vitro, wherein primary mouse bone marrow cells were subsequently exposed to the conditioned media. In addition, we examined mice, and accelerated hematopoiesis via sleep disruption induced by whole body genetic deletion of hypocretin (Hcrt－/－). Hcrt－/－ mice were kept sedentary, or allowed voluntary exercise for 18 weeks, at which point marrow shear sensing was modulated using femoral artery ligation for three weeks thereafter. Bone marrow hematopoietic cell abundances were enumerated using flow cytometry. RESULTS: We found that bone marrow shear sensing transcripts were upregulated in the contralateral unligated compared to the ipsilateral ligated limb after treadmill exercise to exhaustion (mRNA transcripts Notch1, Dll4, Jag1, Klf4; all P < 0.05). That CD31+ bone marrow ECs increased in the ligated (2142 ± 161.9 ECs), compared to unligated (629 ± 771 ECs), limb after exercise indicated further endothelial responsivity. The magnitude of leukocyte egress into systemic circulation was similar between one asplenic and one splenic human after maximal exercise. The marrow, and not other hematopoietic organs such as the spleen, may thus sense shear during exercise. We next examined paracrine signalling. Trends towards increased angiogenic (mRNA transcripts Hif1⍺ and Vegf; P < 0.05) and decreased inflammatory transcriptional programming (mRNA transcript Tnf⍺; P = 0.052) were noted among primary bone marrow cells that were exposed to shear-conditioned EC media. In sleep-disrupted Hcrt－/－ mice, femoral artery ligation abrogated exercise-induced decreases in hematopoietic progenitor cell (MPP2) abundances in the ipsilateral flow-restricted leg compared to the contralateral leg. CONCLUSION: Together, these data indicate that modulating the bone marrow hemodynamic environment may alter ECs shear stress sensing during exercise and may influence hematopoiesis in a paracrine manner. This work was funded by an NSERC Discovery Grant awarded to MJM: 20011033.
Read CV Joshua CherubiniECSS Paris 2023: OP-MH23