ECSS Paris 2023: CP-PN02
INTRODUCTION: Sex differences in skeletal muscle morphology and function start in utero and evolve throughout life due to interactions between genetic, hormonal, and environmental factors. However, the molecular mechanisms driving these differences across the lifespan remain unclear. This study investigates how muscle structure and gene expression change with age in males and females, aiming to identify factors contributing to sex-specific muscle aging and function. METHODS: A total of 96 biological males and 96 biological females aged 18–80 years and stratified by decade participated in this study. Body composition was assessed using dual-energy X-ray absorptiometry (DXA) and peripheral quantitative CT (pQCT) scans. Muscle strength was evaluated through a leg press 5-repetition maximum (RM) test. Muscle biopsies collected from the vastus lateralis were analysed using RNA sequencing (RNA-seq) and immunohistochemical (IHC) staining, with all statistical analyses conducted in RStudio (version 4.3.1). RESULTS: Preliminary transcriptomic analysis revealed distinct sex- and age-associated patterns in gene expression. Pathways related to energy metabolism and cellular respiration exhibited notable differences between sexes, while age-related variations in the male cohort were particularly evident in pathways linked to immune function and protein degradation. CONCLUSION: Ongoing analyses will integrate the muscle transcriptome with sex hormones, body composition, muscle morphology, and function to provide a comprehensive understanding of how sex differences in muscle present across the lifespan. By identifying the molecular and structural factors that contribute to sex-specific muscle aging, this study will enhance our understanding of muscle health, disease susceptibility, and performance across different life stages.
Read CV Karel Van BelleghemECSS Paris 2023: CP-PN02
INTRODUCTION: Middle-aged women often experience menopause which drastically changes physiological function called as “menopausal symptoms (e.g., vasomotor symptoms, sleep disorders and mood depression)” (Nelson, 2008, Guidozzi, 2013). Sleep disorder is known to be a major menopausal symptom, resulting in sustained fatigue and impaired quality of life. During sleep, core body temperature gradually reduced, and elevated core body temperature during sleep disrupts sleep quality (Flecher et al., 1999). Although dysfunction of body temperature during sleep (i.e., lack of lowering body temperature) may be associated with decreased sleep quality in menopausal women, change in body temperature during sleep has not been sufficiently reported in menopausal women. Therefore, the present study aimed to compare body temperature fluctuations and sleep status between menopausal women and young women. METHODS: 19 menopausal women (MW; 49.1±2.7 years old) and 14 young women (YW; 20.3± 0.8 years old) were recruited. Skin temperature (Tsk) at proximal site was measured continuously over 7 days. Subjective sleep parameters were evaluated using Pittsburgh Sleep Quality Index (PSQI), and objective sleep parameters were evaluated using actigraphy. RESULTS: Tsk during sleep was significantly higher in MW (35.0±0.4℃) than YW (34.6±0.5℃, p < 0.05). In YW, Tsk was elevated immediately after falling asleep and then gradually decreased, whereas in MW, no decrease in TSK was found (p < 0.05). Also, TSK remained significantly higher in MW compared to YW during 20-80% phase for whole night (p < 0.05). In subjective sleep parameters evaluated by PSQI, sleep quality was significantly impaired in MW compared to YW (p < 0.05). However, objective sleep parameters evaluated by actigraphy did not differ significantly between groups (p > 0.05). CONCLUSION: Menopausal women presented specific change in nocturnal body temperature compared with young women. The lack of decrease in body temperature during sleep may be associated with impaired subjective sleep quality. [Reference] 1) Fletcher A, van den Heuvel C, Dawson D. Sleeping with an electric blanket: effects on core temperature, sleep, and melatonin in young adults. Sleep. 1999 May 1;22(3):313-8. 2) Guidozzi F. Sleep and sleep disorders in menopausal women. Climacteric. 2013 Apr;16(2):214-9. 3) Nelson HD, Humphrey LL, Nygren P et al. Postmenopausal hormone replacement therapy: scientific review. JAMA. 2002 Aug 21;288(7):872-81.
Read CV Chihiro TomiishiECSS Paris 2023: CP-PN02
INTRODUCTION: Whether the menstrual cycle (MC) influences athletic performance in eumenorrheic females is subject of ongoing scientific investigation with controversial results. Current methodological recommendations emphasize the importance of accurate MC phase determination and classification, to reduce the risk of hidden effects due to inadequate methodology. This review therefore focuses exclusively on studies that combine serum analysis of 17ß-estradiol and progesterone with luteinizing hormone (LH) surge detection to determine the MC phases. METHODS: The databases Medline, PubMed, Scopus and SPORTDiscus were searched for studies that investigated objective athletic performance in at least two different MC phases in eumenorrheic females. RESULTS: The search yielded 1024 results, of which 98 % were excluded, primarily due to inadequate cycle phase determination. 19 studies with a total of n = 279 subjects (25.6 ± 3.6 years) were included. The populations investigated ranged from sedentary, to moderately active to athletic, with a mean sample size of n = 13.9 ± 7. On average, three MC phases were compared (range two – six), with the early follicular (EF) phase being most frequently analyzed in 18 studies. The risk of bias in most studies was rated as medium to high, especially in domains as the randomization process and the selection of reported outcomes. 58 % of the studies reported that at least one objective performance parameter differed between the MC phases. However, the direction and extent of the effects are variable in some cases. One study found maximal aerobic capacity to be impaired during the EF phase. Also, ventilation during submaximal running and cycling was reported to be reduced during the EF phase. In two studies, peak sprinting power was impaired in the late luteal and EF phase, when estradiol and progesterone concentrations are low. Seven out of eight studies on maximum voluntary contraction found no effect of the MC phase on performance. Only one reported enhanced strength during the late follicular compared to the mid luteal phase. All of the three studies investigating coordinative skills and agility reported improved performance during the ovulatory phase. CONCLUSION: Despite the restriction to studies with high methodological standards, it remains difficult to compare the results. This is mainly due to the heterogeneity of the MC phases and populations studied, and the risk of bias. However, contrary to the current state of scientific knowledge, various athletic performance parameters appeared to be influenced by the MC phase in more than half of the studies examined. Our results suggest impaired peak sprinting power during the low hormone phases and increased coordination and agility during ovulation. Maximum strength, jump height and aerobic endurance were largely unaffected by the MC phase.
Read CV Jennifer SchlieECSS Paris 2023: CP-PN02