Changes In Lean Body Mass Research Articles

What are the criteria for response to cachexia treatment?

The treatment of cancer cachexia remains an unmet medical need. One of the barriers to the development and approval of effective interventions has been the lack of agreement on the proper endpoints for study. The international consensus definition of cancer cachexia focuses on 3 major components of the syndrome. This includes altered body composition characterized specifically by loss of skeletal muscle mass. The muscle loss in turn is a result of negative protein and energy balance secondary to reduced food intake and abnormal metabolism. The result of muscle loss is progressive functional impairment. The assessment of interventions for cancer cachexia should include measures of all 3 components of cancer cachexia. For patients with cancer cachexia, body composition measurements of lean body mass (LBM) and fat mass may be best determined by CT imaging. Nutritional endpoints and measures of metabolism can be quite complex. However, change in appetite and body weight remain extremely useful measures of clinical benefit. The most controversial area relates to assessment of physical function. While stair climb power, 6-minute walk, hand grip strength and other measures have been used in clinical trials, none of them have shown consistent benefit that correlates with change in LBM. While we have much to learn about the inter-relationship between muscle mass and muscle function, improvement in physical function may be best measured by patient reported outcomes. Ongoing and future clinical trials in cancer cachexia should assess all 3 domains, which will improve our understanding of this syndrome and ultimately lead to better treatment options for our patients.

Pharmacological management of cachexia in adult cancer patients: a systematic review of clinical trials

BackgroundCachexia is a multisystem syndrome characterized by weight loss, anorexia, loss of muscle mass, systemic inflammation, insulin resistance, and functional decline. Management of cachexia involves addressing multiple underlying biological mechanisms. Previous review on pharmacological management of cancer cachexia identified progestins and corticosteroids as effective agents for treatment of cachexia. However, to date no consensus exists on a single effective or standard treatment for management of cachexia. The aim of this systematic review is to determine the effectiveness of pharmacological treatments used to manage cachexia among adult cancer patients.MethodsWe performed literature searches of PubMed (NLM), Embase (Ovid), and Medline(Ovid) to identify clinical trials focused on pharmacological management of cancer cachexia among adult cancer patients from 2004 to 2018. Three reviewers screened a random selection of abstracts to measure for interrater reliability. After this step, each screener screened two-thirds of all abstracts and 177 studies were identified for full text review. The primary outcome was impact of pharmacological management on change in either weight or lean body mass in cancer patients.ResultsWe identified 19 articles (representing 20 RCTs) that focused on pharmacological management of cancer cachexia. Agents showing promising results included Anamorelin and Enobosarm. Anamorelin at 50 or 100 mg per day for 12 weeks showed a consistent benefit across all studies and resulted in significant improvement in weight as compared to baseline among cancer patients. Enobosarm at 1 and 3 mg per day was also effective in improving lean body mass and QOL symptoms among advancer stage cancer patients. Finally, use of combination agents provide evidence for targeting multiple pathways underlying cachexia mechanism to achieve maximum benefit. No agents showed functional improvement in cancer patients.ConclusionAnamorelin as a single agent shows promising results in improving cachexia related weight loss among cancer patients. Further research on combination therapies may be helpful to address critical gaps in cachexia management.

Effects of protein supplementation on lean body mass, muscle strength, and physical performance in nonfrail community-dwelling older adults: a systematic review and meta-analysis

Increasing protein intake has been suggested as an effective strategy to ameliorate age-related loss of muscle mass and strength. Current reviews assessing the effect of protein supplementation are strongly influenced by the inclusion of studies with frail older adults. We assessed the effect of protein supplementation on lean body mass, muscle strength, and physical performance in exclusively nonfrail community-dwelling older adults. Moreover, we assessed the superior effects of protein supplementation during concomitant resistance exercise training on muscle characteristics. A systematic literature search was conducted on PubMed, Embase, and Web of Science up to 15 May 2018. We included randomized controlled trials that assessed the effect of protein supplementation on lean body mass, muscle thigh cross-sectional area, muscle strength, gait speed, and chair-rise ability and performed random-effects meta-analyses. Data from 36 studies with 1682 participants showed no significant effects of protein supplementation on changes in lean body mass [standardized mean difference (SMD): 0.11; 95% CI: -0.06, 0.28], handgrip strength (SMD: 0.58; 95% CI: -0.08, 1.24), lower extremity muscle strength (SMD: 0.03; 95% CI: -0.20, 0.27), gait speed (SMD: 0.41; 95% CI: -0.04, 0.85), or chair-rise ability (SMD: 0.10; 95%: CI -0.08, 0.28) compared with a control condition in nonfrail community-dwelling older adults. Moreover, no superior effects of protein supplementation were found during concomitant resistance exercise training on muscle characteristics. Protein supplementation in nonfrail community-dwelling older adults does not lead to increases in lean body mass, muscle cross-sectional area, muscle strength, or physical performance compared with control conditions; nor does it exert superior effects when added to resistance exercise training. Habitual protein intakes of most study participants were already sufficient, and protein interventions differed in terms of type of protein, amount, and timing. Future research should clarify what specific protein supplementation protocol is beneficial for nonfrail community-dwelling older adults with low habitual protein intake.

No Difference Between the Effects of Supplementing With Soy Protein Versus Animal Protein on Gains in Muscle Mass and Strength in Response to Resistance Exercise.

Much attention has been given to determining the influence of total protein intake and protein source on gains in lean body mass (LBM) and strength in response to resistance exercise training (RET). Acute studies indicate that whey protein, likely related to its higher leucine content, stimulates muscle protein synthesis to a greater extent than proteins such as soy and casein. Less clear is the extent to which the type of protein supplemented impacts strength and LBM in long-term studies (≥6 weeks). Therefore, a meta-analysis was conducted to compare the effect of supplementation with soy protein to animal protein supplementation on strength and LBM in response to RET. Nine studies involving 266 participants suitable for inclusion in the meta-analysis were identified. Five studies compared whey with soy protein, and four studies compared soy protein with other proteins (beef, milk, or dairy protein). Meta-analysis showed that supplementing RET with whey or soy protein resulted in significant increases in strength but found no difference between groups (bench press: χ2 = 0.02, p = .90; squat: χ2 = 0.22, p = .64). There was no significant effect of whey or soy alone (n = 5) on LBM change and no differences between groups (χ2 = 0.00, p = .96). Strength and LBM both increased significantly in the "other protein" and the soy groups (n = 9), but there were no between-group differences (bench: χ2 = 0.02, p = .88; squat: χ2 = 0.78, p = .38; and LBM: χ2 = 0.06, p = .80). The results of this meta-analysis indicate that soy protein supplementation produces similar gains in strength and LBM in response to RET as whey protein.

Resistance Training and Protein Supplementation Increase Strength After Bariatric Surgery: A Randomized Controlled Trial.

Physical activity and dietary regimens to optimize health outcomes after bariatric surgery are not well known. This study aimed to determine whether resistance training with dietary protein supplementation is effective in maintaining body composition and physical fitness after obesity surgery. Seventy-six women with obesity undergoing Roux-en-Y gastric bypass were randomly assigned at the time of surgery to receive either usual care (controls [CON], n = 22), usual care and additional (whey) protein intake (PRO, n = 31), or usual care, additional protein intake, and supervised strength training for 18 weeks (PRO+EX, n = 23). The primary outcome was pre- to 6-month postsurgery change in lean body mass (by dual-energy x-ray absorptiometry). Secondary outcomes included changes in muscle strength (by one-repetition maximum testing). Loss over time in lean body mass did not differ between groups (CON: mean,-8.8 kg; 95% CI: -10.1 to -7.5 kg; PRO: mean, -8.2 kg; 95% CI: -9.3 to -7.1 kg; PRO+EX: mean, -7.7 kg; 95% CI: -9.0 to -6.5 kg; P = 0.899). The increase in relative lower-limb muscle strength was higher in the PRO+EX group (+0.6 [0.3 to 0.8]) versus +0.1 (-0.1 to 0.4) and +0.2 (0.0 to 0.4) kg/kg body mass in CON and PRO groups, respectively (P = 0.021). Loss in muscle strength observed after bariatric surgery can be overcome by resistance training with additional protein intake.

Effectiveness of exercise training after bariatric surgery-a systematic literature review and meta-analysis.

We aimed to conduct a systematic review and meta-analysis of controlled trials assessing exercise training programs in patients with obesity undergoing bariatric surgery. We systematically searched exercise training studies performed after bariatric surgery published up to June 2017. Studies reporting changes in body composition, physical fitness, functional capacity, objectively measured physical activity, quality of life or relevant health outcomes were included. The review protocol is available from PROSPERO (CRD42017069380). Meta-analyses were conducted using random-effects models when data were available from at least five articles. Twenty articles were included, describing 16 exercise training programs, of which 15 were included in the meta-analysis. Overall, exercise training was associated with higher weight loss (mean difference: -2.4kg, 95% CI: -4.2; -0.6, I2 =49%, n=12), higher fat mass loss (-2.7kg, 95% CI: -4.5; -1.0, I2 =50%, n=8) and improved VO2 max and functional walking (standardized mean difference: 0.86, 95% CI: 0.29; 1.44, I2 =57%, n=6; 1.45, 95% CI: 0.32; 2.58, I2 =89%, n=6, respectively). Exercise training was not associated with lean body mass changes. In conclusion, exercise training programs performed after bariatric surgery were found effective to optimize weight loss and fat mass loss and to improve physical fitness, although no additional effect on lean body mass loss was found.

Trimodal prehabilitation for colorectal surgery attenuates post-surgical losses in lean body mass: A pooled analysis of randomized controlled trials

Preservation of lean body mass is an important cancer care objective. The capacity for prehabilitation interventions to modulate the lean body mass (LBM) of colorectal cancer patients before and after surgery is unknown. A pooled analysis of two randomized controlled trials of trimodal prehabilitation vs. trimodal rehabilitation at a single university-affiliated tertiary center employing Enhanced Recovery After Surgery (ERAS) care was conducted. The prehabilitation interventions included exercise, nutrition, and anxiety-reduction elements that began approximately four weeks before surgery and continued for eight weeks after surgery. The rehabilitation interventions were identical to the prehabilitation interventions but were initiated only after surgery. Body composition, measured using multifrequency bioelectrical impedance analysis, was recorded at baseline, pre-surgery, 4 and 8 weeks after surgery. The primary outcome was change in LBM before and after colorectal surgery for cancer. A mixed effects regression model was used to estimate changes in body mass and body composition over time controlling for age, sex, baseline body mass index (BMI), baseline six-minute walk test (6MWT), and postoperative compliance to the interventions. NCT02586701 &NCT01356264. Pooled data included 76 patients who followed prehabilitation and 63 patients who followed rehabilitation (n=139). Neither group experienced changes in preoperative LBM. Compared to rehabilitated patients, prehabilitated patients had significantly more absolute and relative LBM at four and eight-weeks post-surgery in models controlling for age, sex, baseline BMI, baseline 6MWT, and compliance to the postoperative intervention. Trimodal prehabilitation attenuated the post-surgical LBM loss compared to the loss observed in patients who received the rehabilitation intervention. Patients who receive neither intervention (i.e., standard of care) would be likely to lose more LBM. Offering a prehabilitation program to colorectal cancer patients awaiting resection is a useful strategy to mitigate the impact of the surgical stress response on lean tissue in an ERAS setting, and, in turn, might have a positive impact on the cancer care course. NCT02586701 &NCT01356264 (clinicaltrials.gov).

Phase 1b investigation of the MEK inhibitor binimetinib in patients with advanced or metastatic biliary tract cancer

Background The MAPK pathway plays a central role in regulation of several cellular processes, and its dysregulation is a hallmark of biliary tract cancer (BTC). Binimetinib (MEK162), a potent, selective oral MEK1/2 inhibitor, was assessed in patients with advanced BTC. Patients and Methods An expansion cohort study in patients who received ≤1 line of therapy for advanced BTC was conducted after determination of the maximum tolerated dose in this Phase 1 trial. Patients received binimetinib 60mg twice daily. The primary objectives were to characterize the safety profile and pharmacokinetics of binimetinib in advanced BTC. Secondary objectives included assessment of clinical efficacy, changes in weight and lean body mass, and pharmacodynamic effects. Tumor samples were assessed for mutations in relevant genes. Results Twenty-eight patients received binimetinib. Common adverse events (AEs) were mild, with rash (82%) and nausea (54%) being most common. Two patients experienced grade 4 AEs, one generalized edema and the other pulmonary embolism. The pharmacokinetics in this patient population were consistent with those previously reported (Bendell JC et al., Br J Cancer 2017;116:575-583). Twelve patients (43%) experienced stable disease and two had objective responses (1 complete response, 1 partial response) per Response Evaluation Criteria in Solid Tumors and stable metabolic disease by positron emission tomography/computed tomography. Most patients (18/25; 72%) did not have KRAS, BRAF, NRAS, PI3KCA, or PTEN mutations, nor was there correlation between mutation status and response. The average non-fluid weight gain was 1.3% for lean muscle and 4.7% for adipose tissue. Conclusion Binimetinib was well tolerated and showed promising evidence of activity in patients with BTC. Correlative studies suggested the potential for binimetinib to promote muscle gain in patients with BTC.

A randomized trial of adjunct testosterone for cancer-related muscle loss in men and women.

BackgroundCancer cachexia negatively impacts cancer‐related treatment options, quality of life, morbidity, and mortality, yet no established therapies exist. We investigated the anabolic properties of testosterone to limit the loss of body mass in late stage cancer patients undergoing standard of care cancer treatment.MethodsA randomized, double‐blind, placebo‐controlled phase II clinical trial was undertaken to assess the potential therapeutic role of adjunct testosterone to limit loss of body mass in patients with squamous cell carcinoma of the cervix or head and neck undergoing standard of care treatment including chemotherapy and chemoradiation. Patients were randomly assigned in blocks to receive weekly injections of either 100 mg testosterone enanthate or placebo for 7 weeks. The primary outcome was per cent change in lean body mass, and secondary outcomes included assessment of quality of life, tests of physical performance, muscle strength, daily activity levels, resting energy expenditure, nutritional intake, and overall survival.ResultsA total of 28 patients were enrolled, 22 patients were studied to completion, and 21 patients were included in the final analysis (12 placebo, nine testosterone). Adjunct testosterone increased lean body mass by 3.2% (95% confidence interval [CI], 0–7%) whereas those receiving placebo lost 3.3% (95% CI, −7% to 1%, P = 0.015). Although testosterone patients maintained more favourable body condition, sustained daily activity levels, and showed meaningful improvements in quality of life and physical performance, overall survival was similar in both treatment groups.ConclusionsIn patients with advanced cancer undergoing the early phase of standard of care therapy, adjunct testosterone improved lean body mass and was also associated with increased quality of life, and physical activity compared with placebo.

Cats increase lean body mass with carnitine or carnosine but not with the combination

This study evaluated whether dietary carnitine or carnosine would change lean body mass, circulating cytokines or metabolites in cats. All study protocols were reviewed and approved by the Institutional Animal Care and Use Committee, Hill's Pet Nutrition, Inc., Topeka, KS. Forty four pets were assigned into four groups: Group 1 (n=11) was fed the control diet, group 2 (n=11) was fed the control diet + L‐carnitine (0.03%), group 3 (n=12) was fed the control diet + L‐carnosine (0.1%), and Group 4 (n=10) was fed the Control diet + L‐carnitine + L‐carnosine. The ages of the cats ranged from 7.2 to 13.9 yr. The duration of the study was 6 months. Initial body composition, cytokines and metabolomics profiles were compared to final and changes were compared across treatments. Metabolomics were measured by Metabolon (Morrisville, NC), cytokines were measured by ELISA. Change in lean body mass (LBM) was assessed by Dual‐energy X‐ray absorptiometry (DEXA) and reported in cats as the difference in LBM between initial and final times. Changes in analytes were then compared amongst the 4 groups. Serum levels of cytokines assessed included Flt‐3L, IFN‐γ, IL12p40, IL‐4, IL‐6, IL‐8, IL‐13, IL‐18, and MCP‐1. Modest reductions were observed in the levels of selected cytokines on day 169 when compared to the baseline but these changes were not significant between groups. Lean body mass results showed that cats fed either carnitine alone (+106 g) or carnosine alone (+96 g) had increased lean when compared to control cats or cats supplemented with both carnitine and carnosine (p<0.01). There was no statistical difference between treatments in either body weight or body fat change. Carnitine and deoxycarnitine were increased in the group that had carnitine alone (p<0.05) while many acyl carnitines were increased in both groups supplemented with carnitine. Carnosine was not changed but beta‐alanine was increased in cats fed carnosine. The metabolism of aromatic amino acids (phenylalanine, tyrosine, and tryptophan and dietary polyphenolic compounds) occurs, in part, through the involvement of enzymes encoded within the microbiome. Several microbiota‐derived‐metabolites were higher in Groups 2, 3, and 4 when compared to Group 1 at various time points. These data indicate that supplementation of carnitine or carnosine is beneficial in increasing LBM in felines but that when combined they do not influence LBM.Support or Funding InformationThis study was funded by Hill's Pet Nutrition Inc.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Programming and supervision of resistance training leads to positive effects on strength and body composition: results from two randomised trials of community fitness programmes

BackgroundMany sedentary adults have high body fat along with low fitness, strength, and lean body mass (LBM) which are associated with poor health independently of body mass. Physical activity can aid in prevention, management, and treatment of numerous chronic conditions. The potential efficacy of resistance training (RT) in modifying risk factors for cardiovascular and metabolic disease is clear. However, RT is under researched in public health. We report community-based studies of RT in sedentary (Study 1), and overweight and pre-diabetic (Study 2) populations.MethodsStudy 1 - A semi randomised trial design (48-weeks): Participants choosing either a fitness centre approach, and randomised to structured-exercise (STRUC, n = 107), or free/unstructured gym use (FREE, n = 110), or not, and randomised to physical-activity-counselling (PAC, n = 71) or a measurement only comparator (CONT, n = 76). Study 2 - A randomised wait list controlled trial (12-weeks): Patients were randomly assigned to; traditional-supervised-exercise (STRUC, n = 30), physical-activity-counselling (PAC, n = 23), either combined (COMB, n = 39), or a wait-list comparator (CONT, n = 54). Outcomes for both were BF mass (kg), LBM (kg), BF percentage (%), and strength.ResultsStudy 1: One-way ANCOVA revealed significant between group effects for BF% and LBM, but not for BF mass or strength. Post hoc paired comparisons revealed significantly greater change in LBM for the STRUC group compared with the CONT group. Within group changes using 95%CIs revealed significant changes only in the STRUC group for both BF% (− 4.1 to − 0.9%) and LBM (0.1 to 4.5 kg), and in FREE (8.2 to 28.5 kg) and STRUC (5.9 to 26.0 kg) for strength.Study 2: One-way ANCOVA did not reveal significant between group effects for strength, BF%, BF mass, or LBM. For strength, 95%CIs revealed significant within group changes for the STRUC (2.4 to 14.1 kg) and COMB (3.7 to 15.0 kg) groups.ConclusionStrength increased in both studies across all RT treatments compared to controls, yet significant improvements in both strength and body-composition occurred only in programmed and/or supervised RT. As general increases in physical activity have limited impact upon body-composition, public health practitioners should structure interventions to include progressive RT.Trial registrationStudy 1: ISRCTN13024854, retrospectively registered 20/02/2018. Study 2: ISRCTN13509468, retrospectively registered 20/02/2018).

Influence of Endurance Training During Childhood on Total Hemoglobin Mass

Elite endurance athletes are characterized by markedly increased hemoglobin mass (Hbmass). It has been hypothesized that this adaptation may occur as a response to training at a very young age. Therefore, the aim of this study was to monitor changes in Hbmass in children aged 8–14 years following systematic endurance training. In the first study, Hbmass, VO2max, and lean body mass (LBM) were measured in 17 endurance-trained children (13 boys and 4 girls; aged 9.7 ± 1.3 years; training history 1.5±1.8 years; training volume 3.5 ± 1.6 h) twice a year for up to 3.5 years. The same parameters were measured once in a control group of 18 age-matched untrained children. Hbmass and blood volume (BV) were measured using the optimized CO-rebreathing technique, VO2max by an incremental test on a treadmill, and LBM by skin-fold measurements. In the second pilot study, the same parameters were measured in 9 young soccer athletes (aged 7.8 ± 0.2 years), and results were assessed in relation to soccer performance 2.5 years later. The increase in mean Hbmass during the period of study was 50% which was closely related to changes in LBM (r = 0.959). A significant impact of endurance training on Hbmass was observed in athletes exercising more than 4 h/week [+25.4 g compared to the group with low training volume (<2 h/week)]. The greatest effects were related to LBM (11.4 g·kg−1 LBM) and overlapped with the effects of age. A strong relationship was present between absolute Hbmass and VO2max (r = 0.939), showing that an increase of 1 g hemoglobin increases VO2max by 3.6 ml·min−1. Study 2 showed a positive correlation between Hbmass and soccer performance 2.5 years later at age 10.3 ± 0.3 years (r = 0.627, p = 0.035). In conclusion, children with a weekly training volume of more than 4 h show a 7% higher Hbmass than untrained children. Although this training effect is significant and independent of changes in LBM, the major factor driving the increase in Hbmass is still LBM.

Effect of Protein Intake on Lean Body Mass in Functionally Limited Older Men

The Institute of Medicine set the recommended dietary allowance (RDA) for protein at 0.8 g/kg/d for the entire adult population. It remains controversial whether protein intake greater than the RDA is needed to maintain protein anabolism in older adults. To investigate whether increasing protein intake to 1.3 g/kg/d in older adults with physical function limitations and usual protein intake within the RDA improves lean body mass (LBM), muscle performance, physical function, fatigue, and well-being and augments LBM response to a muscle anabolic drug. This randomized clinical trial with a 2 × 2 factorial design was conducted in a research center. A modified intent-to-treat analytic strategy was used. Participants were 92 functionally limited men 65 years or older with usual protein intake less thanor equal to 0.83 g/kg/d within the RDA. The first participant was randomized on September 21, 2011, and the last participant completed the study on January 19, 2017. Participants were randomized for 6 months to controlled diets with 0.8 g/kg/d of protein plus placebo, 1.3 g/kg/d of protein plus placebo, 0.8 g/kg/d of protein plus testosterone enanthate (100 mg weekly), or 1.3 g/kg/d of protein plus testosterone. Prespecified energy and protein contents were provided through custom-prepared meals and supplements. The primary outcome was change in LBM. Secondary outcomes were muscle strength, power, physical function, health-related quality of life, fatigue, affect balance, and well-being. Among 92 men (mean [SD] age, 73.0 [5.8] years), the 4 study groups did not differ in baseline characteristics. Changes from baseline in LBM (0.31 kg; 95% CI, -0.46 to 1.08 kg; P = .43) and appendicular (0.04 kg; 95% CI, -0.48 to 0.55 kg; P = .89) and trunk (0.24 kg; 95% CI, -0.17 to 0.66 kg; P = .24) lean mass, as well as muscle strength and power, walking speed and stair-climbing power, health-related quality of life, fatigue, and well-being, did not differ between men assigned to 0.8 vs 1.3 g/kg/d of protein regardless of whether they received testosterone or placebo. Fat mass decreased in participants given higher protein but did not change in those given the RDA: between-group differences were significant (difference, -1.12 kg; 95% CI, -2.04 to -0.21; P = .02). Protein intake exceeding the RDA did not increase LBM, muscle performance, physical function, or well-being measures or augment anabolic response to testosterone in older men with physical function limitations whose usual protein intakes were within the RDA. The RDA for protein is sufficient to maintain LBM, and protein intake exceeding the RDA does not promote LBM accretion or augment anabolic response to testosterone. clinicaltrials.gov Identifier: NCT01275365.

Children with severe burns display no sex differences in exercise capacity at hospital discharge or adaptation after exercise rehabilitation training

Background and objectiveFemales have a 50% increased risk of death from burn injury compared to males. However, whether exercise capacity and exercise induced training adaptations differ between burned boys and girls is unknown. This project tested the hypothesis that girls with burns have lower exercise capacity and different exercise induced training adaptations. MethodsTwenty-five girls were matched to 26 boys (mean, 95%CI; years 13 [12,14], cm 151 [143,161], kg 54 [45,63]; each P>0.05) for burn injury (% total body surface area burn, 54 [45,62]; P=0.82). Lean body mass (LBM), strength (peak torque) and cardiorespiratory fitness (peak VO2) were normalized to kg LBM and compared as a percentage of age–sex matched non-burned children (n=26 boys, years 13 [12,14]; n=25 girls, years 13 [12,14]) at discharge (DC) and after aerobic and resistance rehabilitation exercise training (RET). ResultsUsing a 2-way factorial ANOVA (group×time), we found both groups had similar 11% change in LBM (87.3% of non-burned values [82.2,92.3]) and after the RET (92.8% [87.2,98.3]; main effect, time P<0.0001). Peak torque increased similarly by 16% in both groups (% of age–sex matched non-burned DC, 55.9 [51.3,60.5]; after RET, 77.5 [72.1,82.9]; main effect, time P<0.0001). Likewise, peak VO2 increased in both groups by 15% (% of age–sex matched non-burned DC, 56.8 [52.4,61.2] to RET, 72.2 [67.6,76.8]; main effect, time; P<0.0001). Burned children exercise at greater percentage of their peak VO2 and peak HR compared to non-burned children (Interaction, group×time, P<0.0001). ConclusionThe burn injury does not have sex-dependent effects on LBM or exercise capacity in severely burn injured children. Differences in relative peak VO2 and peak HR suggest the need for burn specific exercise programs for improving the efficacy of a rehabilitation program.

The Three-Month Effects of a Ketogenic Diet on Body Composition, Blood Parameters, and Performance Metrics in CrossFit Trainees: A Pilot Study.

Adopting low carbohydrate, ketogenic diets remains a controversial issue for individuals who resistance train given that this form of dieting has been speculated to reduce skeletal muscle glycogen levels and stifle muscle anabolism. We sought to characterize the effects of a 12-week ketogenic diet (KD) on body composition, metabolic, and performance parameters in participants who trained recreationally at a local CrossFit facility. Twelve participants (nine males and three females, 31 ± 2 years of age, 80.3 ± 5.1 kg body mass, 22.9 ± 2.3% body fat, 1.37 back squat: body mass ratio) were divided into a control group (CTL; n = 5) and a KD group (n = 7). KD participants were given dietary guidelines to follow over 12 weeks while CTL participants were instructed to continue their normal diet throughout the study, and all participants continued their CrossFit training routine for 12 weeks. Pre, 2.5-week, and 12-week anaerobic performance tests were conducted, and pre- and 12-week tests were performed for body composition using dual X-ray absorptiometry (DXA) and ultrasound, resting energy expenditure (REE), blood-serum health markers, and aerobic capacity. Additionally, blood beta hydroxybutyrate (BHB) levels were measured weekly. Blood BHB levels were 2.8- to 9.5-fold higher in KD versus CTL throughout confirming a state of nutritional ketosis. DXA fat mass decreased by 12.4% in KD (p = 0.053). DXA total lean body mass changes were not different between groups, although DXA dual-leg lean mass decreased in the KD group by 1.4% (p = 0.068), and vastus lateralis thickness values decreased in the KD group by ~8% (p = 0.065). Changes in fasting glucose, HDL cholesterol, and triglycerides were similar between groups, although LDL cholesterol increased ~35% in KD (p = 0.048). Between-group changes in REE, one-repetition maximum (1-RM) back squat, 400 m run times, and VO2peak were similar between groups. While our n-sizes were limited, these preliminary data suggest that adopting a ketogenic diet causes marked reductions in whole-body adiposity while not impacting performance measures in recreationally-trained CrossFit trainees. Whether decrements in dual-leg muscle mass and vastus lateralis thickness in KD participants were due to fluid shifts remain unresolved, and increased LDL-C in these individuals warrants further investigation.

Efficacy of ketogenic diet on body composition during resistance training in trained men: a randomized controlled trial

BackgroundKetogenic diets (KD) have become a popular method of promoting weight loss. More recently, some have recommended that athletes adhere to ketogenic diets in order to optimize changes in body composition during training. This study evaluated the efficacy of an 8-week ketogenic diet (KD) during energy surplus and resistance training (RT) protocol on body composition in trained men.MethodsTwenty-four healthy men (age 30 ± 4.7 years; weight 76.7 ± 8.2 kg; height 174.3 ± 19.7 cm) performed an 8-week RT program. Participants were randomly assigned to a KD group (n = 9), non-KD group (n = 10, NKD), and control group (n = 5, CG) in hyperenergetic condition. Body composition changes were measured by dual energy X-ray absorptiometry (DXA). Compliance with the ketosis state was monitored by measuring urinary ketones weekly. Data were analyzed using a univariate, multivariate and repeated measures general linear model (GLM) statistics.ResultsThere was a significant reduction in fat mass (mean change, 95% CI; p-value; Cohen’s d effect size [ES]; − 0.8 [− 1.6, − 0.1] kg; p < 0.05; ES = − 0.46) and visceral adipose tissue (− 96.5 [− 159.0, − 34.0] g; p < 0.05; ES = − 0.84), while no significant changes were observed in the NKD and CG in fat mass (− 0,5 [− 1.2, 0.3] kg; p > 0.05; ES = − 0.17 and − 0,5 [− 2.4, 1.3] kg; p > 0.05; ES = − 0.12, respectively) or visceral adipose tissue (− 33.8 [− 90.4, 22.8]; p > 0.5; ES = − 0.17 and 1.7 [− 133.3, 136.7]; p > 0.05; ES = 0.01, respectively). No significant increases were observed in total body weight (− 0.9 [− 2.3, 0.6]; p > 0.05; ES = [− 0.18]) and muscle mass (− 0.1 [− 1.1,1.0]; p > 0,05; ES = − 0.04) in the KD group, but the NKD group showed increases in these parameters (0.9 [0.3, 1.5] kg; p < 0.05; ES = 0.18 and (1.3[0.5, 2.2] kg; p < 0,05; ES = 0.31, respectively). There were no changes neither in total body weight nor lean body mass (0.3 [− 1.2, 1.9]; p > 0.05; ES = 0.05 and 0.8 [− 0.4, 2.1]; p > 0.05; ES = 0.26, respectively) in the CG.ConclusionOur results suggest that a KD might be an alternative dietary approach to decrease fat mass and visceral adipose tissue without decreasing lean body mass; however, it might not be useful to increase muscle mass during positive energy balance in men undergoing RT for 8 weeks.

Associations between ACE-Inhibitors, Angiotensin Receptor Blockers, and Lean Body Mass in Community Dwelling Older Women.

Studies suggest that ACE-inhibitors (ACE-I) and angiotensin receptor blockers (ARBs) may preserve skeletal muscle with aging. We evaluated longitudinal differences in lean body mass (LBM) among women diagnosed with hypertension and classified as ACE-I/ARB users and nonusers among Women's Health Initiative participants that received dual energy X-ray absorptiometry scans to estimate body composition (n=10,635) at baseline and at years 3 and 6 of follow-up. Of those, 2642 were treated for hypertension at baseline. Multivariate linear regression models, adjusted for relevant demographics, behaviors, and medications, assessed ACE-I/ARB use/nonuse and LBM associations at baseline, as well as change in LBM over 3 and 6 years. Although BMI did not differ by ACE-I/ARB use, LBM (%) was significantly higher in ACE-I/ARB users versus nonusers at baseline (52.2% versus 51.3%, resp., p=0.001). There was no association between ACE-I/ARB usage and change in LBM over time. Reasons for higher LBM with ACE-I/ARB use cross sectionally, but not longitundinally, are unclear and may reflect a threshold effect of these medications on LBM that is attenuated over time. Nevertheless, ACE-I/ARB use does not appear to negatively impact LBM in the long term.

Development of a Novel Six-Month Nutrition Intervention for a Randomized Trial in Older Men with Mobility Limitations.

Nutrition impacts the development of sarcopenia and protein intake is an important modulator of skeletal muscle mass loss in older people. The Optimizing Protein Intake in Older Men with Mobility Limitation (OPTIMEN) Trial was designed to assess the independent and combined effects of higher protein intake and a promyogenic agent, testosterone, on lean body mass, muscle strength and physical function in older men with mobility disability. The purpose of this paper is to describe the experimental design and nutrition intervention, including techniques used by research dietitians to develop and deliver energy and protein-specific meals to the homes of community-dwelling participants. Strategies to enhance long-term dietary compliance are detailed. Randomized, double-blind, placebo-controlled six-month intervention trial. Participants were recruited from Boston MA USA and surrounding communities. Older men who were mobility-limited (Short Physical Performance Battery (SPPB) 3-10) and consuming less protein (<0.83 g/kg/day) were recruited for this study. Here we report the successful implementation of a double-blind, placebo-controlled, parallel group, randomized controlled trial with a 6-month intervention period among community-living men, age 65 years and older with a mobility limitation. A controlled feeding plan was used to deliver required energy intakes and prescribed protein quantities of 0.8 or 1.3 grams/kilogram/day (g/kg/d) in three meals plus snacks and supplements. A 2x2 factorial design was used to assess the effects of protein level alone and in combination with testosterone (vs. placebo) on changes in lean body mass (primary outcome), muscle strength, and physical function. A total of 154 men met the eligibility criteria; 112 completed a 2-week run-in period designed to evaluate compliance with the nutrition intervention. Of these, 92 subjects met compliance eligibility criteria and agreed to be randomized; 85% completed the full trial. The study successfully delivered three meals per day to subjects, with a high degree of compliance and subject satisfaction. Overall self-reported compliance rates were 80% and 93% for the meals and supplements, respectively. Details of compliance strategies are discussed. This community-based study design may serve as a model for longer-term nutritional interventions requiring monitoring of dietary compliance in a home-based feeding and supplementation trial.

Effects of Postexercise Protein Intake on Muscle Mass and Strength During Resistance Training: Is There an Optimal Ratio Between Fast and Slow Proteins?

While effects of the two classes of proteins found in milk (i.e., soluble proteins, including whey, and casein) on muscle protein synthesis have been well investigated after a single bout of resistance exercise (RE), the combined effects of these two proteins on the muscle responses to resistance training (RT) have not yet been investigated. Therefore, the aim of this study was to examine the effects of protein supplementation varying by the ratio between milk soluble proteins (fast-digested protein) and casein (slow-digested protein) on the muscle to a 9-week RT program. In a double-blind protocol, 31 resistance-trained men, were assigned to 3 groups receiving a drink containing 20g of protein comprising either 100% of fast protein (FP(100), n = 10), 50% of fast and 50% of slow proteins (FP(50), n = 11) or 20% of fast protein and 80% of casein (FP(20), n = 10) at the end of training bouts. Body composition (DXA), and maximal strength in dynamic and isometric were analyzed before and after RT. Moreover, blood plasma aminoacidemia kinetic after RE was measured. The results showed a higher leucine bioavailability after ingestion of FP(100) and FP(50) drinks, when compared with FP(20) (p< .05). However, the RT-induced changes in lean body mass (p < .01), dynamic (p < .01), and isometric muscle strength (p < .05) increased similarly in all experimental groups. To conclude, compared with the FP(20) group, the higher rise in plasma amino acids following the ingestion of FP(100) and FP(50) did not lead to higher muscle long-term adaptations.

Body composition and adipokines plasma levels in patients with myasthenia gravis treated with high cumulative glucocorticoid dose

This study aimed to evaluate changes in body composition, i.e. overweight, obesity, fat accumulation and low lean body mass and plasma levels of adipokines in patients with MG. The study enrolled 80 patients with MG, and 62 controls. Body fat mass and body lean mass was analyzed by dual-energy X-ray absorptiometry technique (DXA). Plasma levels of leptin were analyzed by Luminex® and adiponectin and resistin were analyzed by ELISA. The mean age of patients with MG was 41.9years, with 13.5years of length of illness, and mean cumulative dose of glucocorticoids 38,123mg. Our results showed that the frequency of obesity is higher in MG patients than in controls, and patients with MG presented higher body fat mass, android body adiposity and total body fat than controls. MG patients presented lower levels of resistin and higher levels of leptin in comparison with controls. There were no differences in the plasma levels of adiponectin. Higher total body fat and lower body lean mass were associated with increased severity of MG symptoms. This result points to the relevance of estimation of body composition in planning long-term care of MG patients.