Lean Mass Research Articles

Muscle-to-Bone Ratio in NCAA Division I Collegiate Football Players by Position.

Dengel, DR, Studee, HR, Juckett, WT, Bosch, TA, Carbuhn, AF, Stanforth, PR, and Evanoff, NG. Muscle-to-bone ratio in NCAA division I collegiate football players by position. J Strength Cond Res XX(X): 000-000, 2024-The purpose of this study was to compare the muscle-to-bone ratio (MBR) in National Collegiate Athletic Association Division I football players (collegiate football players [CFP]) to healthy, age-matched controls. In addition, we examined MBR in CFP by position. A total of 553 CFP and 261 controls had their total and regional lean mass (LM), fat mass (FM), and bone mineral content (BMC) determined by dual x-ray absorptiometry (DXA). College football players were categorized by positions defined as offensive linemen (OL), defensive linemen (DL), tight end, linebacker (LB), running back (RB), punter or kicker, quarterback (QB), defensive back (DB), and wide receiver (WR). There were significant differences between CFP and controls for total LM (80.1 ± 10.0 vs. 56.9 ± 7.8 kg), FM (22.2 ± 12.5 vs. 15.2 ± 7.1 kg), and BMC (4.3 ± 0.5 vs. 3.1 ± 0.5 kg). Although there were significant differences in body composition between CFP and controls, there was no significant differences in total MBR between CFP and controls (18.6 ± 1.4 vs. 18.8 ± 1.7). Regionally, CFP had significantly lower trunk MBR than controls (26.7 ± 2.7 vs. 28.7 ± 4.2), but no difference was seen in leg or arm MBR. Positional differences in CFP were noted as total MBR being significantly higher in DL (19.0 ± 1.4) than in DB (18.1 ± 1.3), WR (18.1 ± 1.3), and LB (18.2 ± 1.3). OL had a significantly higher total MBR (19.2 ± 1.3) than DB (18.1 ± 1.3), LB (18.2 ± 1.3), QB (18.1 ± 1.0), and WR (18.1 ± 1.3). In addition, RB had significantly higher total MBR (18.8 ± 1.3) than DB (18.1 ± 1.3) and WR (18.1 ± 1.3). This study may provide athletes and training staff with normative values when evaluating total and regional MBR with DXA.

Effects of a physical exercise programme on bodyweight, body condition score and chest, abdominal and thigh circumferences in dogs

BackgroundResearch on the effects of physical exercise on canine body composition is limited. The aim of this study was to investigate the effects of a physical exercise programme on bodyweight, body condition score (BCS) and chest, abdominal and thigh circumferences in dogs. Twenty-one healthy dogs of different breeds exercised together with their owners during an eight-week programme consisting of jogging and strength exercises. Standardised measurements were performed in triplicates with a measuring tape on standing dogs. Chest circumference was measured at three anatomical locations, abdomen at two and thigh at one. Data on bodyweight, BCS (9-point scale) and circumferences were analysed with mixed model repeated measures analyses to evaluate changes after the programme and effects of target distance.ResultsSeven dog owners choose a target distance of 2 km and 14 owners choose 5–10 km. Mean BCS decreased (P = 0.007) after the programme (5.1 ± 0.9 vs. 4.7 ± 0.6) but there was no effect of target distance. Almost all chest and abdominal circumference measurements decreased (P ≤ 0.007) with the 2 km group driving the reduction in chest circumference and the 5–10 km group driving the reduction in abdominal circumference. In contrast, thigh circumference (28.8 ± 0.4 vs. 30.2 ± 0.4) increased (P = 0.007) while bodyweight was maintained. There were positive correlations between BCS and abdominal/chest ratios before and after the programme (Pearson correlation; R square ≤ 0.43, P ≤ 0.0012) but the mean ratio remained constant.ConclusionsResults indicated a redistribution between total body fat and muscle mass in body composition of normal weight to slightly overweight dogs after the physical exercise programme. The use of bodyweight alone was not a reliable evaluation method to complement the BCS assessment. However, repeated measurements of chest, abdominal and thigh circumference might aid in the assessment of body composition in dogs performing physical exercise. Further research should include a control group and objective evaluations of total body fat and lean mass, in order to investigate the effectiveness of physical exercise as a freestanding method for decreasing BCS and increasing muscle mass in overweight dogs.

Physiological characteristics predictive of passing military physical employment standard tasks for ground close combat occupations in men and women.

Challenges for some women meeting the physical employment standards (PES) for ground close combat (GCC) roles stem from physical fitness and anthropometric characteristics. The purpose of this study was to identify the modifiable and nonmodifiable characteristics predictive of passing GCC-based PES tasks and determine the modifiable characteristics suitable to overcome nonmodifiable limitations. 107 adults (46 women) underwent multiday testing assessing regional and total lean mass (LM), percent body fat (BF%), aerobic capacity (V̇O2peak), strength, power, and PES performance. Predictors with p-value <0.200 were included in stepwise logistic regression analysis or binary logistic regression when outcomes among sexes were insufficient. Relative and absolute arm LM (OR: 4.617-8.522,p<0.05), leg LM (OR: 2.463, p<0.05), and upper body power (OR: 2.061, p<0.05) predicted medicine ball chest throw success. Relative and absolute arm LM (OR: 3.734-11.694, p<0.05), absolute trunk LM (OR: 2.576, p<0.05), and leg LM (OR: 2.088, p<0.05) predicted casualty drag success. Upper body power (OR: 3.910, p<0.05), absolute trunk LM (OR: 2.387, p<0.05), leg LM (OR: 2.290, p<0.05), and total LM (OR: 1.830, p<0.05) predicted maximum single lift success. Relative and absolute arm LM (OR: 3.488-7.377, p<0.05), leg LM (OR: 1.965, p<0.05), and upper body power (OR: 1.957, p<0.05) predicted water can carry success. %BF (OR: 0.814, p=0.007), V̇O2peak (OR: 1.160, p=0.031), and lower body strength (OR: 1.059, p<0.001) predicted repeated lift and carry success. V̇O2peak (OR: 1.540, p<0.001) predicted 2-km ruck march success. Modifiable characteristics were the strongest predictors for GCC-based PES task success to warrant their improvement for enhancing PES performance for women.

Effects of Short-Term Nighttime Carbohydrate Restriction Method on Exercise Performance and Fat Metabolism.

The sleep-low method has been proposed as a way to sleep in a low-glycogen state, increase the duration of low glycogen availability and sleep and temporarily restrict carbohydrates to improve exercise performance. However, long-term dietary restriction may induce mental stress in athletes. Therefore, if it can be shown that the effects of the sleep-low method can be achieved by restricting the carbohydrate intake at night (the nighttime carbohydrate restriction method), innovative methods could be developed to reduce weight in individuals with obesity and enhance athletes' performance with reduced stress and in a shorter duration when compared with those of previous studies. With this background, we conducted a study with the purpose of examining the intervention effects of a short-term intensive nighttime carbohydrate restriction method. A total of 22 participants were recruited among university students participating in sports club activities. The participants were assigned at random to groups, including a nighttime carbohydrate restriction group of 11 participants (6 males, 5 females; age 22.3 ± 1.23) who started a carbohydrate-restricted diet and a group of 11 participants (5 males, 6 females; age 21.9 ± 7.9) who continued with their usual diet. The present study had a two-group parallel design. In the first week, no dietary restrictions were imposed on either group, and the participants consumed their own habitual diets. In the second week, the total amount of calories and carbohydrate intake measured in the first week were divided by seven days, and the average values were calculated. These were used as the daily calorie and carbohydrate intakes in the second week. Only the nighttime carbohydrate restriction group was prohibited from consuming carbohydrates after 4:00 p.m. During the two-week study period, all participants ran for one hour each day before breakfast at a heart rate of 65% of their maximum heart rate. The results obtained from young adults participating in sports showed significant differences in peak oxygen consumption (V·O2peak), work rate max, respiratory quotient (RQ), body weight and lean body mass after the intervention when compared with before the intervention in the nighttime carbohydrate restriction group (p < 0.05). Our findings suggest that the nighttime carbohydrate restriction method markedly improves fat metabolism even when performed for a short period. This method can be used to reduce body weight in individuals with obesity and enhance athletes' performance. However, it is important to consider the intake of nutrition other than carbohydrates.

Rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone (R-CHOP) therapy decreases lean body mass and appendicular skeletal muscle mass index even until one year after the final treatment in patients with B-cell non-Hodgkin lymphoma

Sarcopenia is an independent prognostic factor for several solid cancers, including B-cell non-Hodgkin lymphoma (B-NHL). However, previous reports have measured the parameters of loss of skeletal muscle as sarcopenia only once before chemotherapy and have predicted poor outcomes. In this study, changes in body composition were measured in patients who received rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone (R-CHOP) therapy for B-NHL using the InBody 720 analyzer throughout the therapy. Twenty-seven patients who achieved complete remission and survived for one year after the last cycle were included in the study. Body composition was evaluated immediately before initiation and fourth cycle, and one month and one year after the last cycle. Throughout the follow-up period, the lean body mass index (LBMI) and appendicular skeletal muscle mass index (ASMI) showed significant transient decreases even one year following the last cycle (p < 0.001, p = 0.002, respectively). Body fat index (BFI) and body fat percentage (BF%) decreased until one month after the last cycle; however, they reached levels higher than the baseline levels, +22.1% and +15.9%, respectively, at 1 year from the last cycle. The loss of skeletal muscle mass did not recover even one year after the last cycle. Interventions in nutritional management are needed to prevent sarcopenia in patients treated with R-CHOP therapy.

Body shape from birth to adulthood is associated with skeletal development: A Mendelian randomization study

BackgroundObservational studies have shown that childhood obesity is associated with adult bone health but yield inconsistent results. We aimed to explore the potential causal association between body shape and skeletal development. MethodsWe used two-sample Mendelian randomization (MR) to estimate causal relationships between body shape from birth to adulthood and skeletal phenotypes, with exposures including placental weight, birth weight, childhood obesity, BMI, lean mass, fat mass, waist circumference, and hip circumference. Independent genetic instruments associated with the exposures at the genome-wide significance level (P < 5 × 10−8) were selected from corresponding large-scale genome-wide association studies. The inverse-variance weighted analysis was chosen as the primary method, and complementary MR analyses included the weighted median, MR-Egger, weighted mode, and simple mode. ResultsThe MR analysis shows strong evidence that childhood (β = −1.29 × 10−3, P = 8.61 × 10−5) and adulthood BMI (β = −1.28 × 10−3, P = 1.45 × 10−10) were associated with humerus length. Tibiofemoral angle was negatively associated with childhood BMI (β = −3.60 × 10−1, P = 3.00 × 10−5) and adolescent BMI (β = −3.62 × 10−1, P = 2.68 × 10−3). In addition, genetically predicted levels of appendicular lean mass (β = 1.16 × 10−3, P = 1.49 × 10−13), whole body fat mass (β = 1.66 × 10−3, P = 1.35 × 10−9), waist circumference (β = 1.72 × 10−3, P = 6.93 × 10−8) and hip circumference (β =1.28 × 10−3, P = 4.34 × 10−6) were all associated with tibia length. However, we found no causal association between placental weight, birth weight and bone length/width. ConclusionsThis large-scale MR analysis explores changes in growth patterns in the length/width of major bone sites, highlighting the important role of childhood body shape in bone development and providing insights into factors that may drive bone maturation.

P-780 Bone health in Danish children aged 7-10 years born after assisted reproductive technology with frozen and fresh embryo transfer

Abstract Study question Is bone health in children conceived after frozen embryo transfer (FET) different from children conceived after fresh embryo transfer (fresh-ET) and natural conception (NC)? Summary answer FET-children had higher bone mineral density (BMD) and bone mineral content (BMC) compared to fresh-ET-children. Insulin-like-growth-factor-I (IGF-I) levels and lean bodymass were similar between groups. What is known already Children conceived after assisted reproductive technology (ART) with FET have a higher average birthweight (BW) and increased risk of being born large-for-gestational-age (LGA) while children born after fresh-ET are more often born small-for-gestational-age (SGA). In general, BW is a determinant of BMD and BMC in childhood with LGA being associated with higher BMD and BMC compared to children born appropriate-for-gestational-age. The relationship between BW and BMD and BMC may be mediated by IGF-I levels and lean bodymass as IGF-I is an important regulator of muscle and bone development. Bone health in children born after ART is scarcely explored. Study design, size, duration This study was part of the large Danish cohort study “Health in Childhood following Assisted Reproductive Technology” (HiCART) which included 606 singletons (292 boys) born in Denmark between 2009 and 2013. The children were conceived after FET (n = 200), fresh-ET (n = 203) and NC (n = 203) and matched for birth year and sex. The study examinations were performed from January 2019 to September 2021. Participants/materials, setting, methods The children underwent a clinical examination at 7-10 years of age with anthropometric measurements, pubertal staging, a fasting blood sample and a whole-body dual-energy x-ray absorptiometry-scan (DXA). Anthropometric measurements and circulating growth factors were converted to standard deviation scores (SDS) using Danish reference material. The study groups were compared pairwise using univariate linear regression and multiple linear regression adjusting for relevant confounders including sex, age, puberty, maternal pregestational BMI, breastfeeding and BW (SDS). Main results and the role of chance Children conceived after FET had significantly higher BW (SDS) (mean, SD: 0.20 SDS, 1.09) compared to children conceived after fresh-ET (-0.22 SDS, 1.00), mean difference: 0.42 SDS (95% CI: 0.21; 0.62) and NC (-0.16 SDS, 1.09), mean difference: 0.35 SDS (95% CI: 0.14; 0.57). In the adjusted model, children born after FET had significantly higher total BMD (g/cm2) (mean difference 0.01, 95% CI: 0.00; 0.03) and size-adjusted BMC (BMC/height, g/m) (mean difference 0.21, 95% CI: 0.01; 0.40) compared to children born after fresh-ET. There was no significant difference in total BMD or BMC/height when comparing FET and fresh-ET to NC children, respectively. There was a trend towards higher lean bodymass (g) in children born after FET and lower lean bodymass in children born after fresh-ET compared to NC children, however this did not reach the level of significance. IGF-I (SDS), IGF-binding-protein-3 (SDS) and serum calcium (mmol/L) levels were comparable between the groups. In the entire cohort, there was a significantly positive correlation between BW (SDS) and size-adjusted BMC (BMC/height, g/m) (b: 0.21, 95% CI: 0.14; 0.27) and total lean bodymass (g) (b: 755, 95% CI: 531; 978), while a significantly negative correlation with IGF-I (SDS) (b: -0.07, 95% CI: -0.13; -0.01). Limitations, reasons for caution The study was powered to detect a clinically relevant difference in BMI (SDS), the primary outcome. Hence, secondary analyses are exploratory by nature. We have no information regarding endometrial preparation protocol in the FET-cycles which may bias the results. Multiple testing may increase our risk of type I errors. Wider implications of the findings Reassuringly, BMD and size-adjusted BMC in children born after ART with FET and fresh-ET were comparable to NC children. Potential determinants of BMD and BMC (IGF-I and lean bodymass) were also similar. Increased BMD and size-adjusted BMC in FET compared to fresh-ET suggests that the different BW-profiles play a role. Trial registration number NCT03719703

P-784 Visceral and subcutaneous adipose tissue in children born after assisted reproductive technology with frozen and fresh embryo transfer

Abstract Study question Is the distribution of abdominal visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) comparable between children following assisted reproduction and natural conception (NC)? Summary answer Children following frozen embryo transfer (FET) have significantly lower VAT/SAT-ratio than children following NC. However, this is not believed to be clinically important. What is known already It is well-established that an adverse distribution of the abdominal adipose tissue with high VAT/SAT-ratio increases the risk of cardiometabolic diseases, hence the VAT/SAT-ratio is closely related to the metabolic profile. Children conceived after FET and fresh embryo transfer (Fresh-ET) are at risk of being born large-for-gestational-age (LGA) and small-for-gestational-age (SGA), respectively. Both, being born LGA and SGA, increases the risk of obesity in later life. To the best of our knowledge, no studies have reported the VAT/SAT-ratio in children following assisted reproductive technology (ART) (both FET and Fresh-ET). Study design, size, duration Prospective observational cohort study including 150 singletons aged 7- to 10-years old conceived after FET (n = 50), Fresh-ET (n = 50) and NC (n = 50). All children were born in Eastern Denmark. The study is conducted between November 2018 and August 2020. Participants/materials, setting, methods This is a substudy af the “Health in Childhood following Assisted Reproductive Technology” (HiCART) study. The children underwent abdominal magnetic resonance imaging (MRI) for the quantification of abdominal adipose tissue along with measurements of anthropometric measurements, blood pressure, fasting blood samples and Dual-energy X-ray Absorptiometry (DXA) scan. The volumes of VAT and SAT were semi-automatically quantified blinded for the mode of conception. Multivariate linear regression analysis of the VAT/SAT-ratio was performed to adjust for confounders. Main results and the role of chance The VAT/SAT-ratio differed significantly between the three groups (mean SD; FET 0.26 (0.08), Fresh-ET 0.29 (0.07), NC 0.30 (0.08), ANOVA, p = 0.014). Pairwise comparison revealed that children conceived after FET had significantly lower VAT/SAT-ratio as compared to children conceived after NC (p = 0.007). In addition, children following FET tended to have lower VAT/SAT-ratio as compared to the Fresh-ET group (p = 0.059). Multivariate linear regression analysis of the VAT/SAT-ratio confirmed a lower VAT/SAT-ratio in FET after adjustment for potential confounding factors (child age and sex, maternal age at delivery and maternal BMI at pregnancy and child birth weight and BMI). Repeat-analysis of 20 MRI showed good intra-rater reliability of VAT and SAT quantifications. As previously reported in the HiCART studies, there were no differences between the groups in anthropometric measurements including body mass index (BMI), lean body mass, blood pressure or high-sensitivity C-reactive protein (hs-CRP). However, the level of triglycerides was found to be significantly higher in Fresh-ET compared to FET and NC (p = 0.028). Limitations, reasons for caution Selection bias cannot be excluded as only children from Eastern Denmark were invited. The observational nature of a cohort study prevents the establishment of causality. Wider implications of the findings Reassuringly, this study found no clinical important difference in abdominal adipose tissue between children following ART (both FET and Fresh-ET) and NC. However, future studies in larger cohorts are warranted. Trial registration number ClinicalTrials.gov identifier: NCT03719703

Opioid-Free Anesthesia with a Mixture of Dexmedetomidine, Ketamine and Lidocaine in Severely Obese Patients Undergoing Laparoscopic Cholecystectomy

Abstract Background Opioids have historically been a first-line therapy for surgical pain control. They were considered optimum and the mainstay for balanced anesthesia but recently the concerns about their side effects were raised. The concept of opioid free anesthesia (OFA) was introduced to provide a safer alternative that would provide benefits to selective group of patients as well as enhance recovery after surgery. Methods The current study compares the use of a mixture of dexmedetomidine and ketamine infusion with traditional fentanyl infusion intra-operative on many variables both intra-operative and post- operative in laparoscopic surgeries. Number of patients who will need rescue narcotics after extubation and total nalbuphine consumption, hemodynamic events (bradycardia, hypotension and hypertension), time to extubation, time to reach Alderete score of 9, post-operative hypoxemia, vomiting, pain scores were recorded and compared with the traditional balanced anesthesia (TBA). Results Forty patients were enrolled in the study, 20 patients in each group. The 2 groups, TBA and OFA, were comparable in demographic data (age, sex, body mass index (BMI), lean body weight (LBW)) and duration of surgery. There was significant decrease in pain scores, number of patients who will need rescue narcotics after extubation and nalbuphine consumption in the OFA group that extended to 24 h post-operative. TBA group showed statistically significant less time needed for extubation (P-value 0.018) and reaching Aldrete score of 9 (P-value 0.02). Conclusions OFA has a better profile than TBA as regard to post-operative pain score and opioid consumption post-operative but they have relative increase in time to extubation and time to reach Aldrete score of 9, and they were equally safe regarding post operative hypoxia and hemodynamics.

Transgender healthcare: metabolic outcomes and cardiovascular risk.

Transgender identity is often associated with gender dysphoria and minority stress. Gender-affirming hormone treatment (GAHT) includes masculinising or feminising treatment and is expected to be lifelong in most cases. Sex and sex hormones have a differential effect on metabolism and CVD in cisgender people, and sex hormone replacement in hypogonadism is associated with higher vascular risk, especially in ageing individuals. Using narrative review methods, we present evidence regarding metabolic and cardiovascular outcomes during GAHT and propose recommendations for follow-up and monitoring of metabolic and cardiovascular risk markers during GAHT. Available data show no increased risk for type 2 diabetes in transgender cohorts, but masculinising GAHT increases lean body mass and feminising GAHT is associated with higher fat mass and insulin resistance. The risk of CVD is increased in transgender cohorts, especially during feminising GAHT. Masculinising GAHT is associated with a more adverse lipid profile, higher haematocrit and increased BP, while feminising GAHT is associated with pro-coagulant changes and lower HDL-cholesterol. Assigned male sex at birth, higher age at initiation of GAHT and use of cyproterone acetate are separate risk factors for adverse CVD markers. Metabolic and CVD outcomes may improve during gender-affirming care due to a reduction in minority stress, improved lifestyle and closer surveillance leading to optimised preventive medication (e.g. statins). GAHT should be individualised according to individual risk factors (i.e. drug, dose and form of administration); furthermore, doctors need to discuss lifestyle and preventive medications in order to modify metabolic and CVD risk during GAHT. Follow-up programmes must address the usual cardiovascular risk markers but should consider that biological age and sex may influence individual risk profiling including mental health, lifestyle and novel cardiovascular risk markers during GAHT.

Association of lipid-lowering drugs with risk of sarcopenia: a drug target mendelian randomization study and meta-analysis

BackgroundLipid-lowering drugs are widely used among the elderly, with some studies suggesting links to muscle-related symptoms. However, the causality remains uncertain.MethodsUsing the Mendelian randomization (MR) approach, we assessed the causal effects of genetically proxied reduced low-density lipoprotein cholesterol (LDL-C) through inhibitions of hydroxy-methyl-glutaryl-CoA reductase (HMGCR), proprotein convertase subtilisin/kexin type 9 (PCSK9), and Niemann-Pick C1-like 1 (NPC1L1) on sarcopenia-related traits, including low hand grip strength, appendicular lean mass, and usual walking pace. A meta-analysis was conducted to combine the causal estimates from different consortiums.ResultsUsing LDL-C pooled data predominantly from UK Biobank, genetically proxied inhibition of HMGCR was associated with higher appendicular lean mass (beta = 0.087, P = 7.56 × 10− 5) and slower walking pace (OR = 0.918, P = 6.06 × 10− 9). In contrast, inhibition of PCSK9 may reduce appendicular lean mass (beta = -0.050, P = 1.40 × 10− 3), while inhibition of NPC1L1 showed no causal impact on sarcopenia-related traits. These results were validated using LDL-C data from Global Lipids Genetics Consortium, indicating that HMGCR inhibition may increase appendicular lean mass (beta = 0.066, P = 2.17 × 10− 3) and decelerate walking pace (OR = 0.932, P = 1.43 × 10− 6), whereas PCSK9 inhibition could decrease appendicular lean mass (beta = -0.048, P = 1.69 × 10− 6). Meta-analysis further supported the robustness of these causal associations.ConclusionsGenetically proxied HMGCR inhibition may increase muscle mass but compromise muscle function, PCSK9 inhibition could result in reduced muscle mass, while NPC1L1 inhibition is not associated with sarcopenia-related traits and this class of drugs may serve as viable alternatives to sarcopenia individuals or those at an elevated risk.

Dynamic Response of Musclin, a Myokine, to Aerobic Exercise and Its Interplay with Natriuretic Peptides and Receptor C.

Musclin, recently identified as a myokine, has been recognized for its physiological significance in potentiating the functional properties of natrieutic peptides (NPs) through competitive inhibition of their clearance receptor, natrieutic peptide receptor C (NPR-C). This study, for the first time in the literature, investigated the dynamic response of musclin during and after aerobic exercise in humans, exploring its potential as a myokine and its interaction with NPs and NPR-C in the context of exercise-induced metabolic responses. Twenty-one inactive young males participated, and we assessed changes in serum levels of musclin, atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), epinephrine (Epi), and glycerol as an indicative of lipid mobilization, during and after moderate-intensity aerobic exercise. Furthermore, we evaluated the gene expression of NPR-C in subcutaneous fat biopsies. Serum musclin levels increased significantly during aerobic exercise, followed by a decline during recovery, remaining elevated compared to baseline. Significant correlations were found between musclin responses and lean body mass (LBM), indicating its regulation by skeletal muscle mass and exercise. Exercise-induced changes in musclin positively correlated with those of ANP, potentially preventing ANP degradation. Additionally, a potential interplay between NPR-C expression and musclin dynamics on ANP was suggested. However, musclin's influence on lipid mobilization was not predominant when considering other lipolytic factors during exercise. Musclin's classification as a myokine is supported by its response to aerobic exercise and its association with LBM. Additionally, its interactions with NPR-C and NPs suggest its physiological relevance and potential clinical implications.

Measurement ofenergy availability in highly trained male endurance athletes and examination of its associations with bone health and endocrine function.

Despite the introduction of Relative Energy Deficiency in Sport (RED-s) in 2014, there is evidence to suggest that male endurance athletes still present with a high prevalence of low energy availability (LEA). Previous findings suggest that energy availability (EA) status is strongly correlated with impairments in endocrine function such as reduced leptin, triiodothyronine (T3), and insulin, and elevated bone loss. This study aimed to report the current EA status, endocrine function and bone health of highly trained Irish male endurance athletes. In this cross-sectional study, participants (n = 3 triathletes; n = 10 runners) completed a 7-day testing period during the competition season using lab-based measures, to ascertain EA status, hormone level and rates of bone metabolism. Serum blood samples were obtained to assess hormone levels and markers of bone metabolism. Mean EA was < 30kcal/kg lean body mass (LBM)/day in 76.9% of athletes. There was a strong association between LEA and low carbohydrate intake, and lower LBM. Mean levels of insulin, IGF-1 and leptin were significantly lower than their reference ranges. Elevated mean concentrations of β-CTX and a mean P1NP: β-CTX ratio < 100, indicated a state of bone resorption. The EA level, carbohydrate intake, hormone status and bone metabolism status of highly trained male endurance athletes are a concern. Based on the findings of this study, more frequent assessment of EA across a season is recommended to monitor the status of male endurance athletes, in conjunction with nutritional education specific to EA and the associated risks.

The effects of intermittent fasting on body composition and cardiometabolic health in adults with prediabetes or type 2 diabetes: A systematic review and meta-analysis.

To perform a meta-analysis to investigate the effects of intermittent fasting (IF), as compared with either a control diet (CON) and/or calorie restriction (CR), on body composition and cardiometabolic health in individuals with prediabetes and type 2 diabetes (T2D). PubMed, Web of Science, and Scopus were searched from their inception to March 2024 to identify original randomized trials with parallel or crossover designs that studied the effects of IF on body composition and cardiometabolic health. Weighted mean differences (WMDs) or standardized mean differences with 95% confidence intervals (CIs) were calculated using random-effects models. Overall, 14 studies involving 1101 adults with prediabetes or T2D were included in the meta-analysis. IF decreased body weight (WMD -4.56 kg [95% CI -6.23 to -2.83]; p = 0.001), body mass index (BMI; WMD -1.99 kg.m2 [95% CI -2.74 to -1.23]; p = 0.001), glycated haemoglobin (HbA1c; WMD -0.81% [95% CI -1.24 to -0.38]; p = 0.001), fasting glucose (WMD -0.36 mmol/L [95% CI -0.63 to -0.09]; p = 0.008), total cholesterol (WMD -0.31 mmol/L [95% CI -0.60 to -0.02]; p = 0.03) and triglycerides (WMD -0.14 mmol/L [95% CI -0.27 to -0.01]; p = 0.02), but did not significantly decrease fat mass, insulin, low-densitiy lipoprotein, high-density lipoprotein, or blood pressure as compared with CON. Furthermore, IF decreased body weight (WMD -1.14 kg [95% CI -1.69 to -0.60]; p = 0.001) and BMI (WMD -0.43 kg.m2 [95% CI -0.58 to -0.27]; p = 0.001), but did not significantly affect fat mass, lean body mass, visceral fat, insulin, HbA1c, lipid profiles or blood pressure. Intermittent fasting is effective for weight loss and specific cardiometabolic health markers in individuals with prediabetes or T2D. Additionally, IF is associated with a reduction in body weight and BMI compared to CR, without effects on glycaemic markers, lipid profiles or blood pressure.

Adherence to the Mediterranean diet is associated with handgrip strength in postmenopausal women

Objective This study aimed to assess the possible association of adherence to the Mediterranean diet (MD) with muscle strength and body composition. Methods The cross-sectional study evaluated 112 postmenopausal women (aged 41–71 years). Fasting blood samples were obtained for biochemical/hormonal assessment. The Mediterranean Dietary Score (MedDietScore) was calculated and used to stratify adherence by tertiles (low [T1], moderate [T2] or high [T3]). Handgrip strength (HGS) was measured by dynamometry and body composition with dual-X-ray absorptiometry. Results Women with low–moderate MedDietScore (T1/T2) had lower HGS values than those with higher scores (19.5 ± 4.9 kg vs. 21.9 ± 3.9 kg, p = 0.023). A linear stepwise increase of HGS values per MedDietScore tertile was found (T1 vs. T2 vs. T3: 18.4 ± 4.4 kg vs. 20.6 ± 5.2 kg vs. 21.9 ± 3.9 kg, ANOVA p-value for linear trend = 0.009, ANCOVA p-value = 0.026). Multivariable models confirmed that HGS values were independently associated with the MedDietScore (β-coefficient = 0.266, p = 0.010). Lean mass values were associated with the MedDietScore (β-coefficient = 0.205, p = 0.040). All models were adjusted for age and cardiometabolic risk factors. Conclusions The data suggest that the higher the adherence to the MD, the better the muscle strength and lean mass in postmenopausal women. Prospective studies are required to evaluate the significance of these observations in cardiovascular prevention strategies at midlife.

Changes in body weight and composition, metabolic parameters, and quality of life in patients with type 2 diabetes treated with subcutaneous semaglutide in real-world clinical practice.

Subcutaneous once-weekly (ow) semaglutide is a recent treatment option for type 2 diabetes (T2D) and obesity, but real-world data on weight loss and associated changes in body composition, nutrients intake, and quality of life are still scarce. This observational, prospective clinical study involved all T2D patients starting ow semaglutide according to routine care between December 2021 and February 2022. Clinical information was collected after 6 months (T6) and 12 months (T12) from semaglutide initiation (T0). Bioelectrical Impedance Analysis (BIA) was performed to measure changes in body composition. Diabetes Treatment Satisfaction Questionnaire (DTSQ) and the 36 - items Short Form Health Survey (SF-36) were administered as patient-reported outcomes (PROs). Changes in continuous endpoints (weight, body composition, nutrients intake, other clinical parameters, and PROs) were assessed using mixed models for repeated measurements. Overall, 90 patients (age 63.0 ± 10.0 years; diabetes duration 7.6 ± 5.9 years; 58.9% men; HbA1c 7.7 ± 1.1%; weight 95.4 ± 19.4 Kg, BMI 34.6 ± 6.4 Kg/m2; 36.7% naïve to diabetes treatment, 43.3% on metformin, 10.0% on dual oral therapy, and 10.0% treated with schemes including insulin) were included in the study. After 6 months from semaglutide initiation, body weight significantly decrease by -4.69 Kg (95%CI -6.19;-3.19) (primary endpoint). After 12 months, body weight was further reduced (-5.38 Kg; 95%CI -7.79;-2.97). At BIA, fat mass was significantly reduced by 2.1 Kg after 6 months but only slightly reduced after 12 months vs. baseline; lean mass was also significantly reduced by over 3 Kg both at 6 and 12 months. Intake of all nutrients declined in the first 6 months of therapy, although only lipids reduction reached the statistical significance (-6.73g; p=0.02). Statistically significant improvements in BMI, waist circumference, glycemic control, blood pressure and lipid profile were documented. Satisfaction with treatment (DTSQ questionnaire) and mental health (MCS score of SF-36 questionnaire) significantly increased during the follow-up. The study documented real-world benefits of semaglutide for treating obesity in T2D subjects, with important changes on clinical and patient-reported outcomes. Loss of lean mass associated with weight loss warrants attention; parallel strategies to preserve skeletal muscle and improve physical function, i.e. nutritional education and structured exercise, are of great importance.

Body composition and body mass index are independently associated with widespread pain and experimental pain sensitivity in older adults: a pilot investigation.

Chronic musculoskeletal (MSK) pain is prevalent in older adults and confers significant risk for loss of independence and low quality of life. While obesity is considered a risk factor for developing chronic MSK pain, both high and low body mass index (BMI) have been associated with greater pain reporting in older adults. Measures of body composition that distinguish between fat mass and lean mass may help to clarify the seemingly contradictory associations between BMI and MSK pain in this at-risk group. Twenty-four older adults (mean age: 78.08 ± 5.1 years) completed dual-energy x-ray absorptiometry (DEXA), and pain measures (Graded Chronic Pain Scale, number of anatomical pain sites, pressure pain threshold, mechanical temporal summation). Pearson correlations and multiple liner regression examined associations between body mass index (BMI), body composition indices, and pain. Significant positive associations were found between number of pain sites and BMI (b = 0.37) and total fat mass (b = 0.42), accounting for age and sex. Total body lean mass was associated with pressure pain sensitivity (b = 0.65), suggesting greater lean mass is associated with less mechanical pain sensitivity. The results from this exploratory pilot study indicate lean mass may provide additional resilience to maladaptive changes in pain processing in older adults, and highlights the importance of distinguishing body composition indices from overall body mass index to better understand the complex relationship between obesity and MSK pain in older adults.

Countermovement Jump and Momentum Generation Associations to Fastball Velocity Performance Among Division I Collegiate Pitchers.

Sakurai, M, Qiao, M, Szymanski, DJ, and Crotin, RL. Countermovement jump and momentum generation associations to fastball velocity performance among Division I collegiate pitchers. J Strength Cond Res 38(7): 1288-1294, 2024-The current study explored the relationships between countermovement jump (CMJ) profiles and baseball pitching performance. Nineteen Division I collegiate pitchers performed in-laboratory pitching and bilateral CMJs. Whole-body kinematics and ground reaction force were collected during both pitching and CMJ evaluations. Statistically significant correlations of concentric impulse and peak power in the CMJ test with fastball velocity were observed (r = 0.71 and 0.68). Concentric impulse in CMJ also showed a statistically significant correlation with linear momentum in the anterior-posterior direction during pitching (r = 0.68). Lean body mass and body mass showed statistically significant correlations with both of the 2 linear momentums during pitching (r = 0.71∼0.83), and concentric impulse in CMJ (r = 0.71 and 0.81). Pelvis and trunk pitching mechanics did not correlate with any of the CMJ variables at the statistically significant level, whereas the direction of the correlations varied (|r| < 0.45). Assessment of a baseball pitcher's CMJ should focus on concentric impulse and peak power because only these showed meaningful relationships with fastball velocity or momentum generation during pitching. An increase in lean body mass is also suggested to be able to generate more impulse and momentum. Baseball coaches, strength coaches, and clinicians are encouraged to include lower-body explosive training to enhance the force and power output capacity of baseball pitchers.

Long-term Changes in Body Composition and Exercise Capacity Following Calorie Restriction and Exercise Training in Older Patients with Obesity and Heart Failure With Preserved Ejection Fraction

Obesity combined with heart failure with preserved ejection fraction (HFpEF) is the dominant form of HF among older persons. In a randomized trial, we previously showed that a 5-month calorie restriction (CR) program, with or without aerobic exercise training (AT), resulted in significant weight and fat loss and improved exercise capacity. However, little is known regarding the long-term effects of these outcomes after a short-term (5-month) intervention of CR with or without AT in older patients with obesity and HFpEF. Sixteen participants from either the CR or CR+AT who experienced significant weight loss ≥ 2 kg were reexamined after a long-term follow-up endpoint (28.0 ± 10.8 months) without intervention. The follow-up assessment included body weight and composition via dual-energy X-ray absorptiometry and exhaustive cardiopulmonary treadmill exercise testing. Compared to the 5-month time-point intervention endpoint, at the long-term follow-up endpoint, mean body weight increased +5.2 ± 4.0 kg (90.7 ± 11.2 kg vs 95.9 ± 11.9; P < 0.001) due to increased fat mass (38.9 ± 9.3 vs 43.8 ± 9.8; P < 0.001) with no change in lean mass (49.6 ± 7.1 vs 49.9±7.6; P = 0.67), resulting in worse body composition (decreased lean-to-fat mass). Change in total mass was strongly and significantly correlated with change in fat mass (r = 0.75; P < 0.001), whereas there appeared to be a weaker correlation with change in lean mass (r = 0.50; P = 0.051). Additionally, from the end of the 5-month time-point intervention endpoint to the long-term follow-up endpoint, there were large, significant decreases in VO2peak (-2.2 ± 2.1 mL/kg/min; P = 0.003) and exercise time (-2.4 ± 2.6 min; P = 0.006). There appeared to be an inverse correlation between the change in VO2peak and the change in fat mass (r = -0.52; P = 0.062). Although CR and CR+AT in older patients with obesity and HFpEF can improve body composition and exercise capacity significantly, these positive changes diminish considerably during long-term follow-up endpoints, and regained weight is predominantly adipose, resulting in worsened overall body composition compared to baseline. This suggests a need for long-term adherence strategies to prevent weight regain and maintain improvements in body composition and exercise capacity following CR in older patients with obesity and HFpEF.

The Role of Musculoskeletal Training During Return to Performance Following Relative Energy Deficiency in Sport.

Relative energy deficiency in sport (REDs) is a condition that is associated with negative health and performance outcomes in athletes. Insufficient energy intake relative to exercise energy expenditure, resulting in low energy availability, is the underlying cause, which triggers numerous adverse physiological consequences including several associated with musculoskeletal (MSK) health and neuromuscular performance. This commentary aims to (1) discuss the health and performance implications of REDs on the skeletal and neuromuscular systems and (2) examine the role that MSK training (ie,strength and plyometric training) during treatment and return to performance following REDs might have on health and performance in athletes, with practical guidelines provided. REDs is associated with decreases in markers of bone health, lean body mass, maximal and explosive strength, and muscle work capacity. Restoration of optimal energy availability, mainly through an increase in energy intake, is the primary goal during the initial treatment of REDs with a return to performance managed by a multidisciplinary team of specialists. MSK training is an effective nonpharmacological component of treatment for REDs, which offers multiple long-term health and performance benefits, assuming the energy needs of athletes are met as part of their recovery. Supervised, prescribed, and gradually progressive MSK training should include a combination of resistance training and high-impact plyometric-based exercise to promote MSK adaptations, with an initial focus on achieving movement competency. Progressing MSK training exercises to higher intensities will have the greatest effects on bone health and strength performance in the long term.