ECSS Paris 2023: OP-MH32
INTRODUCTION: Exercise has many systemic effects. Epidemiological studies suggest that exercise can improve the prognosis of cancer patients, but the mechanisms are largely unknown. In animal models, exercise has been shown to slow tumor growth by enhancing the immunological response to tumors. The aim of this study was to investigate the effects of acute exercise on circulating immune cell and cytokine levels in humans with newly diagnosed lymphoma or breast cancer. METHODS: Participants were 15 lymphoma patients (mean (SD) age 59 (17) years) and 29 breast cancer patients (57 (10) years) who had not yet started their cancer treatments. The patients performed either a 10-minute or a 30-minute exercise bout on a bicycle ergometer. Venous blood samples were drawn before, during, and 30 minutes after the exercise to analyze immune cell mobilization and cancer-specific cytokines. RESULTS: Acute exercise increased the number of circulating neutrophils, lymphocytes, monocytes, eosinophils, basophils, CD4+ T cells, T helper (Th) 1 cells, Th2 cells, Th17 cells, regulatory T cells, CD8+ T cells, CD4-CD8- T cells, CD19+ B cells, and CD56+ natural killer (NK) cells. The mobilization of the immune cells was similar in lymphoma patients during the 10- and 30-minute exercises. In breast cancer patients, the mobilization of CD4+ T cells and NK cells was greater during the 30-minute exercise compared the 10-minute exercise, but other cells mobilized similarly during the exercises. The level of IP-10 increased during exercises in both lymphoma and breast cancer patients. Further, the level of Eotaxin, IL-1β, IL-13, and MIP-1α increased during the exercises and the level of MIP-1β, PDGF-BB, and TNF-α decreased 30 minutes after the exercises in breast cancer patients. The levels of Eotaxin and IP-10 increased more during the 30-minute exercise compared to 10-minute exercise in breast cancer patients. CONCLUSION: Acute exercise stimulates the mobilization of anti-tumoral and pro-tumoral immune cells, which is fairly similar during and after 10- and 30-minute exercises. Further studies on the effects of exercise on the tumor microenvironment and tumor growth are needed in humans.
Read CV Tiia KoivulaECSS Paris 2023: OP-MH32
INTRODUCTION: Reported CrossFit injury rates are high; however, there is a paucity of research on injury risk factors. This study investigated if training volume (TV) and heart rate variability (HRV) are injury risk factors among CrossFit athletes. METHODS: This observational longitudinal study included 33 non-elite CrossFit athletes who completed weekly online injury surveys and daily TV. Training volume was calculated as session duration multiplied by the rating of perceived exertion (sRPE) and expressed in arbitrary units (AU). The A:C ratio “safe zone” was set at (0.8-1.3 AU). Acute (total TV over seven days) and chronic (three-week rolling average of the acute TV) TV ratios (A:C ratios) were also calculated. Heart rate variability was assessed using the "HRV4Training" mobile application. Injuries were surveyed using the Oslo Sports Trauma Research Centre (OSTRC) Overuse Injury Questionnaire, adapted to collect data on acute injuries. RESULTS: Mean weekly TV was 1299 ± 675.4 AU, session duration 55.2 ± 32.4 minutes and sRPE 7.4/10. Of the 33 participants, 65.6% of A:C TV was outside the "safe zone.” Thirteen participants (40.9%) sustained injuries and 51 injuries were reported, of which 69% were overuse and 31% acute injuries. The shoulder and ankle were the most common sites of acute and overuse injuries. In the univariate model, TV and HRV were not associated with injury risk. Injury rates were higher among participants aged ≥ 51 years, males, commitment levels four to five (medium), and training two to three times per week. Non-competing CrossFit Open participants had a higher overall injury count with a more significant percentage of injuries than competing participants. Injury probability increased from 11% in week one to 31% in week 16, peaking in those with two years of training experience. CONCLUSION: Training volume (A:C ratios) and HRV were not associated with injury risk. Injury rates were higher among males, participants older than 51 years, with medium training commitment, medium to high frequency of training, and less experience. Although TV and HRV were not identified as individual injury risk factors, they might be related to an increased risk of injury when considered with other variables. Future studies with larger sample sizes should investigate these variables using a multivariate model.
Read CV Candice ChristieECSS Paris 2023: OP-MH32
INTRODUCTION: Osteoarthritis is the second most prevalent musculoskeletal disorder and mostly affects hip and knee joints. Hip and knee osteoarthritis (HKOA) age-standardized prevalence is 3,867 per 100,000 inhabitants in Western Europe. In absence of a curative treatment for HKOA, literature supports that physical activity is one of the major treatment option to reduce pain and increase physical function in these patients. In addition, sedentary behaviour was associated with poor health outcomes, including osteoarthritis. Yet, previous studies that investigated physical activity and sedentary behaviour consequences in this population were based on questionnaires, which are sensitive to recall bias and do not capture the full movement behaviours spectrum. Indeed, these studies did not take into account sleep time nor the compositional nature of movement behaviours. This prospective study aims to investigate the association between objective device-measured movement behaviour and HKOA incidence in participants from the UK Biobank cohort, while addressing the compositional nature of movement behaviours. METHODS: Data from the UK Biobank cohort were used, which included individuals from England, Scotland and Wales registered in the National Health Service and aged 40-69 years old. Incident HKOA cases were ascertained on hospital inpatient data. Movement behaviour was measured with a wrist-worn triaxial accelerometer used during 7 days. Raw data was processed with the GGIR R-package in order to classify the time spend in different movement behaviours, such as sleep, sedentary behaviour, light physical activity (LIPA) and moderate to vigorous physical activity (MVPA). Compositional cox proportional hazard models with age as the time scale and adjusted for sex were used to investigate how reallocating time from one movement behaviour to another (one-to-one reallocation) was associated with HKOA incidence. RESULTS: In total, 90,028 participants without KHOA diagnosis in 2013-2015 were included. During a mean follow-up of 8 years, 5,641 participants developed HKOA. Results showed that reallocating 30min/day to MVPA from sedentary behaviour (HR=0.95, 95%CI=0.94-0.96) or LIPA (HR=0.91, 95%CI=0.89-0.93) was associated with lower HKOA incidence. In addition, reallocating 30min/day to sleep from sedentary behaviour (HR=0.96, 95%CI=0.95-0.97) or LIPA (HR=0.92, 95%CI=0.90-0.93) was also associated with lower HKOA incidence. CONCLUSION: This is the first study using objective measures of physical activity to provide evidence that moderate-to-vigorous physical activity plays a role in HKOA prevention, while accounting for the other movement behaviours. Our results also highlight that increasing sleep duration may help prevent HKOA. This study warrants further studies to elucidate the mechanisms underlying these associations.
Read CV Mathilde MURAECSS Paris 2023: OP-MH32