ECSS Paris 2023: OP-PN23
INTRODUCTION: Growing interest in plant-based diets has fueled debate surrounding differences in dietary intake that could impact musculoskeletal (MSK) health and performance, such as protein, calcium and vitamin D [1]. Few studies have compared MSK properties of vegetarians (VEGT) and vegans (VEG). Early work, however, suggests muscle size and maximal strength in recreationally active male VEG is comparable to that of OMN [2] but bone mineral density (BMD) is lower and fracture risk greater compared with OMN [3]; although other studies show no differences [4]. This study aimed to compare dietary intake and musculoskeletal properties between habitual OMN, VEGT and VEG across the adult lifespan. METHODS: One hundred and fifty-one participants were recruited, in a cross-sectional observational design, having followed their chosen dietary pattern consecutively for > two years. Dietary patterns were self-reported and confirmed via food frequency questionnaires and a three-day weighed food diary. OMN (n=63, males=36, females=27, age=32 ±14 years, stature=1.75±0.08m, body mass=78.2±15.5kg), VEGT (n=24, males=4, females=20, age=36±15 years, stature=1.67±0.09m, body mass=67.4±17.7kg) and VEG (n=64, males=28, females=36, age=43±15 years, stature=1.71±0.08m, body mass=71.3±12.6kg) were assessed for body composition, femoral neck (FN) and total hip bone mineral density (BMD) via dual-energy X-ray absorptiometry. Vastus lateralis (VL) muscle thickness, anatomical (ACSA) and physiological cross-sectional area (PCSA), muscle volume and rectus femoris echo intensity (EI) were assessed via B-mode ultrasonography. Analysis of covariance was used (SPSS v29), controlling for age, sex, dietary adherence duration, self-report physical activity and body mass index, as appropriate. RESULTS: There were no differences between groups for skeletal muscle properties or body composition (P>0.05). Total hip BMD was lower in VEG compared with OMN (VEG=1.09±0.18g/cm2, OMN=1.24±0.18g/cm2; P=0.031), but not VEGT (1.13±0.14g/cm2, P>0.05) and there were no differences in FN BMD between groups (P>0.05). Both calcium and vitamin D intake were similar between groups (P>0.05); however, protein intake was higher in OMN (1.43±0.69 g/kg) compared with VEG (1.14±0.45 g/kg, P=0.029). Leucine intake was also greater in OMN (5697±3718 mg/d) compared with VEGT (2641±1360 mg/d, P= 0.001) and VEG (2405±1886 mg/d, P<0.001). CONCLUSION: This study found no differences between groups for muscle properties (thickness, ACSA, PCSA, volume or EI), despite lower intake of protein and important amino acids in the VEG and VEGT. Total hip BMD was lower in VEG compared to OMN, but is unlikely to be clinically relevant, nor were there differences in FN BMD between groups. There does not appear to be any beneficial or detrimental effects of plant-based diets on muscle or bone health. References 1.Sobiecki et al., 2016,Nutr Res; 2.Page et al., 2021,Eur J Spor Sci; 3.Iguacel et al., 2018, Nutr Rev.; 4.Knurick et al., 2015,Nutrients.
Read CV Joe PageECSS Paris 2023: OP-PN23
INTRODUCTION: Exercise guidelines to improve bone strength generally include resistance-based exercises (1). Beyond mechanical stimulus, sex hormones may also have an effect on bone health, as in vitro studies have demonstrated the influence of 17β-oestradiol on osteocyte function (2). Thus, this study investigated the acute effects of eccentric resistance exercise on procollagen type I N-propeptide (P1NP) and carboxy-terminal cross-linking telopeptide of type I collagen (β-CTX-1) concentrations in premenopausal females. METHODS: Nine eumenorrheic females and ten oral contraceptive (OC) users performed an eccentric-based resistance exercise (10x10 repetitions of back squats with a 4-second eccentric phase) in three of the menstrual cycle (MC) phases [early follicular (EFP), late follicular (LFP) and mid luteal (MLP)] and in the two OC cycle phases [withdrawal (WP) and active pill-taking (APP)], in a randomized testing order. β-CTX-1 and P1NP, 17β-oestradiol and progesterone were assessed pre- and post-exercise. MC and OC cycle phases were confirmed by serum sex hormone analysis. RESULTS: 17β-oestradiol (pg·ml-1) was lower in EFP (36.635±29.930) compared to LFP (224.807±233.813; p=<0.001) and MLP (161.445±110.082; p<0.001) and higher in the WP (24.857±29.428) compared to APP (12.717±13.357; p=0.004). While progesterone (ng·ml-1) was higher in MLP (8.30±5.23) compared to EFP (0.33±0.33; p<0.001) and LFP (0.21±0.18; p<0.001). In eumenorrheic females, β-CTX-1 (ng·ml-1) was lower in MLP (0.395±0.126) compared to LFP (0.472±0.137; p=0.044). Comparing ovarian hormonal profiles, eumenorrheic females had higher P1NP levels (ng·ml-1) compared to OC users: EFP (62.54±13.13) vs APP (50.69±8,91; p=0.034), LFP (67.32±18.96) vs WP (52.16±10.72; p=0.047), LFP vs APP (p=0.025), MLP (67.51±19.34; p=0.049) vs WP, MLP vs APP (p=0.027). Exercise time effect showed lower β-CTX-1 concentrations post-exercise (MC: 0.376±0.114, p<0.001; OC: 0.340±0.156, p=0.030) compared to pre-exercise (MC: 0.485±0.137; OC: 0.428±0.188) in all participants. CONCLUSION: Eccentric resistance training decreased β-CTX-1, showing its potential to protect against acute bone resorption. This study underscores the need to understand the characteristics of resistance training for optimal bone health in active females. β-CTX-1 was lower in the MLP compared to LFP of the MC, which may indicate that progesterone can reduce β-CTX-1 without modifying P1NP concentrations. Finally, ovarian hormonal profile influence bone (re)modelling markers, decreasing bone formation in OC users, indicating the need to investigate long-term effects on bone structure and strength. Funding: Grant DEP2016-75387-P funded by MCIN/AEI/10.13039/501100011033 and by “ERDF A way of making Europe". References 1. Beck BR, et al. (2017). doi: 10.1016/j.jsams.2016.10.001 2. Klein-Nulend J. et al (2015). doi: 10.1016/j.jbiomech.2014.12.007
Read CV Isabel Guisado CuadradoECSS Paris 2023: OP-PN23
INTRODUCTION: The impact of low energy availability (LEA) on bone mineral density (BMD) in transgender women athletes (TWA) remains uncertain, and discussions about LEA have garnered attention in recent years. Thus, we aimed to assess and compare nutritional parameters among volleyball players divided into TWA, cisgender women athletes (CWA), and cisgender men athletes (CMA). Additionally, we aimed to examine the association between nutritional parameters and BMD. METHODS: This is a cross-sectional study. Inclusion criteria involved healthy volleyball players aged 18-39 years; TWA under gender-affirming hormone therapy (GAH) for at least six months. Participants visited the laboratory once. We utilized Dual-energy X-ray absorptiometry to assess body composition (i. e., femur BMD, fat mass and appendicular lean mass (ApLM)). We evaluated blood biomarkers (e.g., vitamin D, calcium, and parathormone [PTH]) in accordance with biochemical kit recommendations. Also, participants completed health and sociodemographic questionnaires along with a 24-hour food recall. Statistical comparisons were conducted using the ANOVA test, and associations were explored through linear regression, considering biological plausibility. Model quality was confirmed using AIC and R2 in regression analysis. Data analysis utilized Jamovi® 2.3.21 version. RESULTS: Data from a preliminary sample of 22 subjects are presented as mean (SD). The mean duration of GAH was 6.8 years, and the average age of GAH onset was 22 years. The ANOVA test indicated no differences in age (30.4 (2.62), 26.0 (4.24), and 28.9 (4.38) years), body mass index (23.2 (3.52), 23.9 (2.57), and 26.8 (5.01) kg/m2), and fat mass (20.9 (9.53), 19.8 (8.81), and 21.4 (10.1) kg) among TWA, CWA, and CMA, respectively. Energy intake is different among groups (F(17,2)= 8.28; p= 0.003; η2ρ= 0.493). For instance, CMA consumed more energy than CWA (Mean Difference [MD]: 1410 kcal; p= 0.003) and TWA (MD: 1142 kcal; p= 0.021), with no significant differences between CWA and TWA (MD: 268 kcal; p= 0.764). However, carbohydrate (F(17,2)= 1.55; p= 0.240; η2ρ= 0.155), protein (F(17,2)= 1.79; p= 0.197; η2ρ= 0.174), and lipid (F(17,2)= 2.01; p= 0.65; η2ρ= 0.191) intake did not differ between groups. Furthermore, serum levels of vitamin D (F(18,2)= 0.415; p= 0.666; η2ρ= 0.044), PTH (F(19,2)= 0.720; p= 0.501; η2ρ= 0.078), and calcium (F(19,2)= 2.49; p= 0.109; η2ρ= 0.208) also did not differ between the groups. Linear regression results (R2: 0.813; F= 4.34; p= 0.036; sample power: 75%) indicated that, regardless of ApLMI, energy intake, vitamin D levels, calcium, and PTH, TWA was negatively associated with femur BMD (B= -0.77; 95% CI: -1.32 to – 0.21; p= 0.018). In contrast, CWA showed no associated with femur BMD compared to CMA (B= -0.31; 95% CI: -0.86 to 0.23; p= 0.227). CONCLUSION: In conclusion, the energy intake of TWA was lower than CMA, with no differences in macronutrient intake or blood biomarkers. Moreover, TWA was negatively associated with femur BMD.
Read CV Marcus QuaresmaECSS Paris 2023: OP-PN23