Changes In Lean Mass Research Articles

The Resilience and the Subsequent Hospitalization of Older People with Different Frailty Status: A Prospective Cohort Study.

To evaluate the difference in resilience across frailty status by measuring the impact of unplanned hospitalization across people with different frailty condition on (1) 2-year changes in lean mass, physical performance, and quality of life, and (2) subsequent hospitalization. A prospective cohort study. Three thousand seventeen older people (73.7 ± 4.9years) were recruited from the community in Hong Kong. Frailty status was defined using the Cardiovascular Health Study scale at baseline. Unplanned hospitalization between the 2 visits was obtained from the Hong Kong Hospital Authority. The interaction of frailty and hospitalization status on the 2-year changes in lean mass, physical performance, and quality of life were examined using 2-way analysis of covariance. Risk of subsequent hospitalization was estimated using Poisson regression. The effect of prolonged hospitalization, which was defined as 6 or more total hospitalized days, was also examined. Upon unplanned hospitalization, frail older people had significantly augmented decline than prefrail and robust people in appendicular skeletal mass (-0.44 ± 0.08kg), height-adjusted appendicular skeletal mas (-0.13 ± 0.03kg/m2), 5-time chair-stand (4.79 ± 0.60s), and mental health (-3.72 ± 0.88). The reduction increased with the length of hospitalization. Unplanned hospitalization conferred an augmented risk of subsequent hospitalization for those who were prefrail and frail (IRR= 1.44, 95% confidence interval= 1.30-1.59 and IRR= 1.69, 95% confidence interval= 1.45-1.97, respectively). The resilience of older people varies according to their frailty status, and the poor resilience may translate to a higher chance of having subsequent hospitalization for prefrail and frail people. These findings emphasized the importance of having the frailty screening in making posthospitalization plans for older people depending on their frailty status and encouraging prefrail and frail older people to build up their resilience.

The Impact of Volume Overload on the Longitudinal Change of Adipose and Lean Tissue Mass in Incident Chinese Peritoneal Dialysis Patients.

Patients treated with peritoneal dialysis (PD) experience complex body composition changes that are not adequately reflected by traditional anthropometric parameters. While lean and adipose tissue mass can be readily assessed by bioimpedance spectroscopy (BIS), there is concern about the potential confounding effect of volume overload on these measurements. This study aimed to assess the influence of fluid status (by echocardiography) on body composition parameters measured by BIS and to describe the longitudinal changes in adipose and lean tissue mass. We conducted a prospective observational study in a tertiary hospital. Incident Chinese PD patients underwent baseline echocardiography and repeated BIS measurements at baseline and 12 months later. Among 101 PD patients, lean tissue index (LTI) or fat tissue index (FTI) was not associated with echocardiographic parameters that reflected left ventricular filling pressure (surrogate of volume status). Sixty-eight patients with repeated BIS had a significant increase in body weight and FTI, while LTI remained similar. Gains in fat mass were significantly associated with muscle wasting (beta = −0.71, p < 0.0001). Moreover, progressive fluid accumulation independently predicted decrease in FTI (beta = −0.35, p < 0.0001) but not LTI. Body composition assessments by BIS were not affected by fluid status and should be considered as part of comprehensive nutrition assessment in PD patients.

The effect of obesity and subsequent weight reduction on cardiac structure and function in dogs

BackgroundIn people, the cardiovascular effects of obesity include systemic hypertension, cardiac remodelling and both systolic and diastolic dysfunction, whilst weight reduction can reverse myocardial remodelling and reduce risk of subsequent cardiovascular disease. To date, variable results are reported in studies of the effect of obesity and controlled weight reduction on cardiovascular morphology and function in dogs. This prospective study aimed to assess cardiac function, heart rate variability, cardiac biomarkers and body composition before and after weight reduction in pet dogs with obesity. Twenty-four client-owned dogs referred for weight management due to obesity were recruited. To assess the cardiac effects of obesity, body composition analysis (by dual energy X-ray absorptiometry, DEXA) and cardiovascular assessment (echocardiography, Doppler blood pressure, electrocardiography, cardiac biomarkers) were performed prior to weight management. Twelve dogs completed the study and reached target weight, receiving a further cardiovascular assessment and DEXA. A Wilcoxon-signed rank test was used to compare each variable pre- and post- weight reduction.ResultsMedian (interquartile range) duration of weight loss was 224 days (124–245 days), percentage weight loss was 23% (18–31%) of starting weight. Median change in body fat mass was -50% (-44% to -55%; P = 0.004), whilst median change in lean mass was -7% (+ 1% to -18%, P = 0.083).Before weight reduction, diastolic dysfunction (evidence of impaired relaxation in all dogs), increased left ventricular wall thickness and mildly elevated systolic blood pressure (14/24 ≥ 160 mmHg, median 165 mmHg (140–183)) were common features in dogs with obesity. However, systolic left ventricular wall dimensions were the only variables that changed after weight reduction, with a decrease in both the systolic interventricular septum (P = 0.029) and systolic left ventricular free wall (P = 0.017). There was no evidence of decreased heart rate variability in dogs with obesity (P = 0.367), and no change in cardiac biomarker concentrations with weight reduction (N-terminal proBNP, P = 0.262; cardiac troponin I P = 0.657).ConclusionsCanine obesity results in diastolic dysfunction and left ventricular hypertrophy, the latter of which improves with significant weight and fat mass reduction. Further studies are required to clarify the clinical consequences of these findings.

Physical Inactivity Forms Negatively Impact Grip Strength And Body Composition In Early Postnatal Mice

FASCM Sponsor: Dr. Kyle Timmerman Background: Physical activity (PA) is a vital behavior to maximize health and wellness. Less is understood regarding the impact of muscle disuse on children, specifically during key stages of skeletal muscle development. The time frame between weaning and sexual maturation is known to be a critical period of development in mice. PURPOSE: We propose that, similar to malnutrition, exposure to muscle disuse early in life will impair growth rate, muscular function and tissue composition. METHODS: We exposed postnatal mice (3-4 weeks old) to 2 weeks of physical inactivity (PIA) in the form of hindlimb unloading (HU) and small mouse cage (SMC) after weaning. Grip strength and body composition were assessed before inactivity and after the inactivity period. RESULTS: Growth rate, assessed as the change in body weight, was 10.18 ± 1.31 g, 6.94 ± 0.46 g, and 5.078 ± 0.59 g for Control, SMC and HU mice (HU < CON: P < 0.05). Average lean mass change in Control was 8.02 ± 0.86 g, 5.57 ± 0.85 g in SMC, and 4.10 ± 0.39 g in HU, between weeks 3 and 5 (HU and SMC < CON: P < 0.01). Absolute max grip strength percent change between weeks 3 and 5 was 108.0 ± 9.34%, 65.76 ± 9.89%, and 55.93 ± 29.54% for Control, SMC and HU, respectively (SMC < CON: P < 0.05). More data will be added for the conference. CONCLUSIONS: Mice subjected to physical inactivity displayed lower growth rates, percent change in max grip strength, and lean mass change compared to control mice. Comparing HU and SMC, HU mice appear to have lower body weight, grip strength and lean mass than SMC mice. Changes in lean mass and body weight suggest significant deficits in physical health that may have bearing on healthy development and aging. Additionally, since grip strength is a strong predictor of health status, reduced functionality, and early mortality, these findings of premature dynapenia (muscle weakness) as a result of early life muscle disuse are concerning. Supported by: Education, Health, and Society Research Seed Grant

Abstract 110: Cullin3 Deficiency In T Lymphocytes Causes A Lean Phenotype With Increased Carbohydrate Catabolism But Promotes Hypertension And Renal Inflammation

Low body mass is associated with increased risk of death and stroke, but the mechanism is unclear. Cullin3 (Cul3) ubiquitin ligase regulates T lymphocyte polarization, insulin signaling, and blood pressure (BP) and may provide a mechanistic link for the cardiometabolic phenotypes. Deletion of Cul3 in T cells ( Cul3 fl/fl x CD4-Cre , termed CD4-Cul3 -/- ) resulted in 17% lower body weight (BW: CD4-Cul3 -/- vs CD4-Cul3 +/+ littermates, 23.9 ± 0.9 vs 28.7 ± 0.7 g, 12-16 wks old, n = 6, 12, p&lt;0.01) and blunted growth curve (ΔBW over 7 wks: 3.2 ± 0.9 vs 5.0 ± 0.6 g) in male mice. No difference in BW or growth curve was observed in females. Nuclear magnetic resonance analysis found decreased fat mass (6.4 ± 0.4 vs 9.2 ± 0.8 g, n = 10, 13, p &lt; 0.01) in male null mice with no change in lean mass or fluid content. This was confirmed by post-mortem quantitation of inguinal fat and interscapular brown adipose tissue. There was no difference in postprandial blood glucose, but the male null mice exhibited lower area under curve (AUC mg/dL x hr, 543 ± 104 vs 765 ± 40, p &lt; 0.05) in glucose tolerance test (2 g/kg, 5 hr fasting) and developed hypoglycemia and seizure during fasting insulin tolerance test (0.5 U/kg). CD4-Cul3 -/- mice had elevated respiratory exchange ratio (ratio between CO 2 produced by the body and O 2 consumed) (0.83 ± 0.01 vs 0.78 ± 0.01, n= 4, p &lt; 0.05), suggesting a larger reliance on carbohydrates rather than lipids as fuel. Baseline BP was comparable in null and control mice. In response to chronic pressor dose of angiotensin (Ang) II (490 ng/kg/min, s.c. 14 days), CD4-Cul3 -/- mice displayed exaggerated hypertension (systolic BP in mmHg: 164 ± 8.4 vs 150.3 ± 4.9; ΔSBP: 35.3 ± 7.5 vs 15.8 ± 5.3, p &lt; 0.05). Mean and diastolic BP were also greater in the null mice, but there was no difference in heart rate or activity. Ang II-infused CD4-Cul3 -/- mice showed a trend towards increased renal CD3 + T cells and significantly increased CD4 + T helper cells (p &lt; 0.05). Thus, T cell Cul3 deficiency caused a lean phenotype characterized by decreased adiposity, increased carbohydrate catabolism, and augmented Ang II-induced hypertension and renal inflammation. The CD4-Cul3 -/- mice may be a useful model to study the association between low body mass and increased cardiovascular risk in humans.

Resistance Training Muscle Adaptations Using D3-creatine Dilution In Older Adults: A Pilot Study

High intensity resistance training (RT) is well known to increase muscle mass in older adults. However, the degree to which is dependent on the measurement method. D3-creatine (D3Cr) dilution is a promising new method that provides a direct and accurate measurement of creatine pool size and whole-body skeletal muscle mass. There are a limited number of studies that compare intervention-based adaptations between D3Cr derived skeletal mass versus lean mass by dual energy x-ray absorptiometry (DXA) Purpose: To evaluate and compare D3Cr derived skeletal mass and DXA lean mass changes following whole body progressive RT in moderate to low functioning older adults. Methods: Twenty-four older adults who tested as moderate to low-functioning on a standardized performance battery were randomized to a whole-body RT or health education program. RT was performed 3 days per week for 14 weeks. It included upper and lower body exercises performed at ~70% of maximal strength in progressive manner. Health education workshops were conducted weekly as an attention “control”. D3Cr dilution and whole body DXA scans were performed prior to randomization and shortly after completion of the programs. Results: D3Cr derived whole body skeletal mass increased more in participants randomized to the RT group compared to the health education group (3.5 ± 2.0 vs. 1.2 ± 1.7 kg, p = 0.03). Mean differences between groups was lower with DXA appendicular lean (RT: 0.81 ± 0.67 vs Education: -0.23 ± 0.70 kg, p = 0.008) and DXA total lean body mass (RT: 1.1 ± 1.4 vs Education: -0.19 ± 0.70 kg, p = 0.06). Pearson correlation coefficients showed weak relationships between changes in D3Cr muscle and DEXA appendicular (0.19, p = 0.48) and total lean mass measures (0.41, p = 0.13). Conclusions: This pilot study demonstrates that D3Cr dilution method is sufficiently sensitive to detect whole body changes in skeletal muscle mass of older adults. The unexpected discordance between D3Cr dilution and traditional DXA based measures of lean mass requires further study.

The Effects of Training Load During Dietary Intervention Upon Fat Loss: A Randomized Crossover Trial

ABSTRACTPurpose: To date no studies have compared resistance training loading strategies combined with dietary intervention for fat loss. Methods: Thus, we performed a randomised crossover design comparing four weeks of heavier- (HL; ~80% 1RM) and lighter-load (LL; ~60% 1RM) resistance training, combined with calorie restriction and dietary guidance, including resistance trained participants (n=130; males=49, females=81). Both conditions performed low-volume, (single set of 9 exercises, 2x/week) effort matched (to momentary failure), but non-work-matched protocols. Testing was completed pre- and post-each intervention. Fat mass (kg) was the primary outcome, and a smallest effect size of interest (SESOI) was established at 3.3% loss of baseline bodyweight. Body fat percentage, lean mass, and strength (7-10RM) for chest press, leg press, and pull-down exercises were also measured. An 8-week washout period of traditional training with normal calorie interspersed each intervention. Results: Both interventions showed small statistically equivalent (within the SESOI) reductions in fat mass (HL: -0.67 kg [95%CI -0.91 to 0.42]; LL: -0.55 kg [95%CI -0.80 to -0.31]) which were also equivalent between conditions (HL – LL: -0.113 kg [95%CI -0.437 kg to 0.212 kg]). Changes in body fat percentage and lean mass were also minimal. Strength increases were small, similar between conditions, and within a previously determined SESOI for the population included (10.1%). Conclusions: Fat loss reductions are not impacted by resistance training load; both HL and LL produce similar, yet small, changes to body composition over a 4-week intervention. However, the maintenance of both lean mass and strength highlights the value of resistance training during dietary intervention.

The Effects of Vision-Deprived Progressive Resistance Training on One-Repetition Maximum Bench Press Performance: An Exploratory Study.

The objective of this study was to determine whether vision-occluded progressive resistance training would increase upper-extremity movement performance using the one-repetition maximum (1-RM) bench press. Participants (n = 57) were recruited from a historically black college and university (HBCU), cross-matched by sex, age (±1 year), 1-RM (±2.27 kg), 1-RM/weight (±0.1), and 1-RM/lean mass ratio (±0.1), and randomly assigned to either the experimental group (vision occluded) or the control group. Participants performed resistance training for 6 weeks prior to beginning the study, and 1-RM was assessed the week prior to the beginning of the study. Weight and body composition were measured using a BOD POD. Of the 57 participants who started the study, 34 completed the study (Experimental = 16, Control = 18) and were reassessed the week after completing the 6-week-long training protocol. Using a combination of Mann–Whitney U and Wilcoxon signed-rank tests, we found that when accounting for changes in lean muscle mass, individuals who trained with their vision occluded reported significantly greater improvements in 1-RM strength compared to those who did not (p < 0.05). The findings from our study suggest that vision-occluded progressive resistance training increases upper-extremity performance when assessed using the bench press. These findings may have significant practical implications in both sports and rehabilitation, as these techniques may be used to enhance performance in athletes and/or improve rehabilitation effectiveness.

Relationships between Body Weight Status and Serum Levels of Adipokine, Myokine and Bone Metabolism Parameters in Healthy Normal Weight and Thin Children.

Optimal body weight and body composition for age are relevant to child development and healthy life. Changes in lean mass and fat mass as well as its distribution are associated with alterations in the secretion of myokines and adipokines by muscle and adipose tissues. These factors are very important for bone health. The aim of the study was to assess serum leptin, adiponectin, resistin, visfatin and omentin as adipokines and myostatin and irisin as myokines with regard to their associations with bone parameters in healthy normal weight and thin children. We studied 81 healthy prepubertal children (aged 5 to 9 years) divided into three groups: group A—35 children with a BMI z-score between +1 and −1 SD; group B—36 children with a BMI z-score between −1 and −2 SD; and group C—10 thin children with a BMI z-score of <−2 SD. We observed significantly (p < 0.001) lower fat mass, fat/lean mass ratio and bone mineral density (BMD) across weight status with the lowest values in the group of thin children. We noticed significantly (p < 0.05) lower concentrations of 25-hydroxyvitamin D, resistin and high-molecular-weight (HMW) adiponectin but higher levels of myostatin as the BMI z-score deceased. We found that BMI and leptin levels were directly correlated with fat mass, lean mass, bone mineral content (BMC) and BMD. Resistin levels were negatively associated with lean mass, while visfatin concentrations were positively related to total BMD. In healthy prepubertal children there were differences in body composition and in bone mineral density across decreasing BMI status. We suggest that changes in serum myostatin and 25-hydroxyvitamin D levels may play a role in bone status of thin children. Moreover, significant relations between adipokines and bone parameters may confirm crosstalk between fat tissue and bone in these children.

Body Composition in Patients With Psoriatic Arthritis and Changes During Interleukin‐12/Interleukin‐23 Inhibition

Little is known about body composition in patients with psoriatic arthritis (PsA). Our objective was to compare body composition parameters in PsA patients and healthy controls and then investigate the effects of ustekinumab (UST) on body composition in patients with PsA. At baseline, 30 PsA patients were compared cross-sectionally with 60 healthy controls without PsA, matched for age, sex, menopausal status, and body mass index (BMI). Thirty active PsA patients treated with UST were included in a 6-month open follow-up study. Body composition parameters were measured at baseline and 6 months of treatment. Body composition parameters were different in PsA patients compared to healthy controls; in PsA patients, total and appendicular lean mass were lower (P=0.013 and P=0.010, respectively), whereas total fat mass was higher (P < 0.001). In 30% of the PsA patients, skeletal muscle mass was below the cutoff for low muscle quantity (men 7.26 kg/m2 , women 5.5 kg/m2 ), whereas no such change was observed in the control group. After 6 months of treatment with UST, there was no significant change in BMI in 18 of the PsA patients. Total lean mass decreased slightly (P=0.046), whereas fat mass tended to increase, but not significantly. No significant changes in appendicular lean mass and skeletal muscle mass index were observed. In this study, we found that PsA patients had higher fat mass and lower lean mass than healthy controls. At 6-months of treatment, total lean mass decreased slightly, whereas fat mass tended to increase, but not significantly.

198-LB: The Loss of the Lysine Acetyltransferase KAT8 in Adipocytes Confers Lipodystrophy and Metabolic Dysfunction in Male and Female Mice

KAT8, also known as MOF or MYST1, is a lysine acetyltransferase with both histone and non-histone substrates. While KAT8 is the major H4K16 acetyltransferase in Drosophila and mammals and is essential for embryonic development, its role in specific cell types is not well understood. Moreover, studies within the past decade have demonstrated lineage-, differentiation state-, or stress-dependent roles of KAT8. Our recent efforts have shown that KAT8 is necessary for in vitro adipogenesis prior to or during the proliferative phase. Notably, several, independent genetic studies reveal that single nucleotide polymorphisms (SNPs) within or near the KAT8 gene are associated with body mass index and/or waist circumference. To investigate the role of KAT8 in differentiated adipocytes and to understand the contribution of KAT8-deficient adipocytes to whole-body glucose and lipid metabolism, we generated both congenital and doxycycline-inducible adipocyte-specific knockout mice, in which Kat8 gene deletion occurs only in adiponectin-expressing cells. Adult mice lacking adipocyte KAT8 exhibited significant fat mass loss with no change in lean mass. While the size of inguinal and brown adipose tissue was significantly reduced in both sexes fed either chow or high-fat, high-sucrose (HFHS) diet, male mice also had decreased gonadal, retroperitoneal, and mesenteric depots. Histological assessments revealed substantial remodeling within adipose tissue depots, and these mice demonstrated reduced insulin sensitivity and increased lipid accumulation in the liver when fed HFHS diet. Although further investigation is necessary to identify KAT8 targets that confer lipodystrophy, these studies are the first to show the impact of the loss of adipocyte KAT8 in vivo. Disclosure A. J. Richard: n/a. T. M. Mendoza: None. J. M. Stephens: None. Funding National Institutes of Health COBRE P&amp;F grant (P30 GM118430)

547-P: Changes in Body Weight and Glucoregulatory Markers by Eight-Hour Time-Restricted Eating vs. Daily Calorie Restriction: A 6-Month Randomized Controlled Trial

Background: Intermittent fasting has gained substantial popularity in the past decade. The most popular form of intermittent fasting is time restricted eating (TRE) , which involves eating within a 4-to-10-hour window and water fasting for the rest of the day. Short-term studies (2 months) indicate that TRE produces mild reductions in body weight and markers of glucose regulation. What remains unknown is whether longer durations of TRE (6-months) can lead to even greater improvements in these diabetes risk factors. In addition, whether TRE is more effective than daily calorie restriction (CR) for improving these endpoints, also remains unknown. Objective: The purpose of this study was to compare the effects of 8-h TRE versus daily CR on body weight, body composition, and markers of glucoregulation, in adults with obesity. Design: Participants were randomized to 1 of 3 groups for 6-months: 8-h TRE (n = 24, 12-8pm eating window, 8pm-12pm fasting window) , CR (n = 22, 25% energy restriction daily) , or a control (n = 19, no food or meal timing restrictions) . Results: Weight loss was not significantly different between the TRE (-3.4 ± 0.7%) and CR group (-4.9 ± 1.4%) by month 6. Only the CR group experienced significant weight loss (P = 0.02) versus controls (-0.7 ± 1.1%) . Changes in fat mass, lean mass, and visceral fat mass were not significantly different between groups post-treatment. Likewise, no significant changes in fasting glucose, fasting insulin, or HbA1c were observed. Changes in insulin resistance (assessed via HOMA-IR) did not differ between TRE (-0.50± 0.35 %) , CR (-0.56 ± 0.39 %) , or controls (0.37 ± 0.43%) . Conclusions: These findings suggest that TRE does not produce greater weight loss than traditional dieting (CR) over 6-months. Our findings also show that neither diet had any beneficial effect on body composition of markers of glucoregulation, versus controls, in adults with obesity. Disclosure S.Cienfuegos: None. S.Lin: None. K.Gabel: None. M.Mcstay: None. A.Mulas: None. K.Varady: None. Funding R01DK128180 , NIH (NIDDK)

Adipose and serum zinc alpha-2-glycoprotein (ZAG) expressions predict longitudinal change of adiposity, wasting and predict survival in dialysis patients

There were limited data on adipose and serum zinc alpha-2-glycoprotein (ZAG) expression and its association with body composition in patients with advanced chronic kidney disease (CKD). This study aimed to quantify adipose and serum ZAG expression and evaluate their association with body composition and its longitudinal change, together with mortality in incident dialysis patients. We performed a single-center prospective cohort study. Patients who were planned for peritoneal dialysis were recruited. ZAG levels were measured from serum sample, subcutaneous and pre-peritoneal fat tissue obtained during peritoneal dialysis catheter insertion. Body composition and functional state were evaluated by bioimpedance spectroscopy and Clinical Frailty Scale respectively at baseline and were repeated 1 year later. Primary outcome was 2-year survival. Secondary outcomes were longitudinal changes of body composition. At baseline, the average adipose and serum ZAG expression was 13.4 ± 130.0-fold and 74.7 ± 20.9 µg/ml respectively. Both adipose and serum ZAG expressions independently predicted adipose tissue mass (ATM) (p = 0.001, p = 0.008, respectively). At 1 year, ATM increased by 3.3 ± 7.4 kg (p < 0.001) while lean tissue mass (LTM) remained similar (p = 0.5). Adipose but not serum ZAG level predicted change in ATM (p = 0.007) and LTM (p = 0.01). Serum ZAG level predicted overall survival (p = 0.005) and risk of infection-related death (p = 0.045) after adjusting for confounders. In conclusion, adipose and serum ZAG levels negatively correlated with adiposity and predicted its longitudinal change of fat and lean tissue mass, whilst serum ZAG predicted survival independent of body mass in advanced CKD patient.

Sex Differences in Bone Health Among Indian Older Adults with Obesity, Sarcopenia, and Sarcopenic Obesity

Age-related changes in fat and lean mass contribute to bone health, but these associations may be influenced by sex and ethnicity. This study investigated sex-specific associations of obesity and sarcopenia with bone mineral density (BMD) and bone mineral apparent density (BMAD) among Indian older adults. 1057 adults aged ≥ 50 years were included. Dual-energy X-ray absorptiometry (DXA) measured BMD at the hip, spine and whole-body, and BMAD was calculated as BMD/√bone area. Obesity was defined by body fat percentage (cut points; > 25% for men and > 35% for women), and sarcopenia was defined using the revised Asian Working Group for Sarcopenia classification with low hand grip strength (< 28 kg for men and < 18 kg for women) and appendicular lean mass index (< 7.0 kg/m2 for men and < 5.4 kg/m2 for women). Participants were classified into four groups: controls (no obesity or sarcopenia), obesity, sarcopenia, or sarcopenic obesity. Linear regression (β-coefficients and 95%CI) analyses were performed with adjustments for age, smoking status, protein intake, and socioeconomic status. Prevalence of sarcopenia (37%) and sarcopenic obesity (6%) were higher in men than women (17% and 4%, respectively). Compared with controls, men with obesity had lower whole-body BMD and BMAD, but women with obesity had higher hip and spine BMD and BMAD (all p < 0.05). Men, but not women, with sarcopenic obesity, had lower hip and whole-body BMD and BMAD (all p < 0.05) than controls. Men with sarcopenia had lower BMD and BMAD at the hip only, whereas women had lower BMD at all three sites and had lower BMAD at the hip and spine (all p < 0.05), compared with controls. Obesity, sarcopenia, and sarcopenic obesity have sex-specific associations with BMD and BMAD in Indian older adults. With the aging population in India, it is important to understand how body composition contributes to poor bone health among older adults.

Short‐duration Aerobic Exercise Improves Chemotherapy Induced Physical Dysfunction in Mice

Chemotherapy regimens for colorectal cancer cause body weight loss, fatigue, and weakness that may persist long after treatment completion. While increased physical activity can help to mitigate these effects, low adherence to standard exercise prescriptions limits the therapeutic potential. Therefore, it is necessary to determine if an exercise threshold is required to improve chemotherapy toxicity. Gaps remain in our understanding of the extent of chemotherapy toxicities after treatment completion, and if a low dose of exercise is sufficient to improve chemotherapy‐induced dysfunction.PurposeTo examine the effects of exercise dose on body composition and physical function in mice during the recovery from Folfox chemotherapy.MethodsMale C57BL/6J mice (12wks) were injected with 4 cycles (1 cycle= 1 injection every other wk) of Folfox (FOL; 5FU 30mg/kg, Oxaliplatin 6mg/kg, Leucovorin 90mg/kg) or PBS. Mice were sacrificed 0wks (n=8) or 4wks (n=16) after the 4th cycle. Subsets of mice performed 14 sessions (6d/wk, 5% grade) of short‐ (15min/d; n=10) or long‐duration (60min/d; n=10) treadmill exercise during recovery. Body composition by MRI, treadmill run time to fatigue (RTF), and grip strength tests were performed pre, post, and after 4wks recovery.ResultsFOL treatment attenuated body mass gain (PBS 10%, FOL 3%) independent of food intake (p=0.586) or cage activity (p=0.801). Fat mass accumulation was decreased (PBS: 56%, FOL: ‐3%) with no changes in lean mass during treatment. During recovery, body mass remained suppressed (‐8%; p=0.022), and RTF (‐43%; p&lt;0.01) and grip strength were reduced (‐9%; p=0.045) in FOL mice compared to PBS. Treadmill exercise improved body weight loss (3%; p=0.041) independent of fat mass. Long‐ compared to short‐duration exercise increased lean mass (p&lt;0.01) in both treatment groups. Both short‐ and long‐duration exercise improved RTF (93%; p&lt;0.01) without improving grip strength.ConclusionRepeated cycles of Folfox chemotherapy can induce persistent deficits in physical function and fat mass. Two weeks of short‐duration aerobic exercise was sufficient to reverse chemotherapy induced fatigue without improving strength. Future studies should examine if the combined effects of aerobic and resistance exercise can improve strength.

Improving skeletal muscle insulin sensitivity via beta2 -agonist administration: a promising strategy to counteract metabolic disease and muscle loss.

Improving skeletal muscle insulin sensitivity via beta2 -agonist administration: a promising strategy to counteract metabolic disease and muscle loss.

Lean Mass Dynamics in Hibernating Bats and Implications for Energy and Water Budgets.

AbstractHibernation requires balancing energy and water demands over several months. Many studies have noted the importance of fat for hibernation energy budgets, but protein catabolism in hibernation has received less attention, and whole-animal changes in lean mass have not previously been considered. We used quantitative magnetic resonance body composition analysis to measure deposition of fat and lean mass of cave myotis (Myotis velifer) during the prehibernation period and decreases in fat and lean mass of Townsend's big-eared bats (Corynorhinus townsendii) during hibernation. For cave myotis, lean mass represented 25% and 38% (female and male, respectively) of prehibernation mass gain. In hibernating Townsend's big-eared bats, lean mass decrease was similar for females and males. We used values for Townsend's big-eared bats to explore the functional implications of lean mass change for water and energy budgets. Lean mass accounted for a substantial proportion of mass change during hibernation (female: 18%, male: 35%), and although not accounting for a large proportion of the energy budget (female: 3%, male: 7%), lean mass catabolism represented an important contribution to water production (female: 14%, male: 29%). Although most mammals cannot rely on protein catabolism for metabolic water production because of the water cost of excreting urea, we propose a variation of the protein-for-water strategy whereby hibernators could temporally compartmentalize the benefits of protein catabolism to periods of torpor and the water cost to periodic arousals when free drinking water is typically available. Combined, our analyses demonstrate the importance of considering changes in lean mass during hibernation.

Bone mineral density and its relationship with body composition indices in stroke patients

Background. Stroke and osteoporosis with its complications are age-related diseases that mainly affect the elderly. The aim of the study was to determine the bone mineral density (BMD, fat and lean mass and their association in stroke patients. Materials and methods. Eighty-six stroke patients and 86 age- and sex-matched individuals without neurological disorders as a comparison group were examined. BMD, lean and fat mass were determined using dual-energy X-ray absorptiometry. Results. Men and women with stroke had a significantly higher frequency of osteoporosis than the comparison group (14.2 vs. 2.3 %; 20.5 vs. 4.4 %, respectively). BMD in women with a stroke was lower at the level of all examined areas, in men; differences were registered at the proximal femur and the total body. In men with stroke, significantly lower lean mass index (17.9 ± 1.5 and 19.2 ± 1.8 kg/m2; p &lt; 0.05) and the appendicular lean mass index (7.5 ± 0.4 and 8.5 ± 1.0 kg/m2; p&lt;0.05) were found, and in women — no significant differences in body composition indices were found, however, the frequency of sarcopenia was significantly higher in both men (28.6 vs. 9.5%, p&lt;0.05) and women (15.9 vs. 2.3%, p&lt;0.05). In men of both groups, positive correlations between total body BMD and lean mass were registered. The dependence of BMD of different areas on fat and lean mass was obtained in stroke women, in contrast to men, in whom the influence of fat mass on BMD was not found. Conclusion. The stroke leads to changes in bone mineral density and lean (muscle) mass and therefore is a risk factor for the development of osteoporosis and sarcopenia.

Muscle hypertrophic effect of inhaled beta2 -agonist is associated with augmented insulin-stimulated whole-body glucose disposal in young men.

Rodent studies highlight enhancement of glucose tolerance and insulin sensitivity as potential clinically relevant effects of chronic beta2‐agonist treatment. However, the doses administered to rodents are not comparable with the therapeutic doses used for humans. Thus, we investigated the physiological effects of prolonged beta2‐agonist treatment at inhaled doses resembling those used in respiratory diseases on insulin‐stimulated whole‐body glucose disposal and putative mechanisms in skeletal muscle and adipose tissue of healthy men. Utilizing a randomized placebo‐controlled parallel‐group design, we assigned 21 healthy men to 4 weeks daily inhalation of terbutaline (TER; 4 mg × day−1, n = 13) or placebo (PLA, n = 8). Before and after treatments, we assessed subjects’ whole‐body insulin‐stimulated glucose disposal and body composition, and collected vastus lateralis muscle and abdominal adipose tissue biopsies. Glucose infusion rate increased by 27% (95% CI: 80 to 238 mg × min−1, P = 0.001) in TER, whereas no significant changes occurred in PLA (95% CI: −37 to 195 mg × min−1, P = 0.154). GLUT4 content in muscle or adipose tissue did not change, nor did hexokinase II content or markers of mitochondrial volume in muscle. Change in lean mass was associated with change in glucose infusion rate in TER (r = 0.59, P = 0.03). Beta2‐agonist treatment in close‐to‐therapeutic doses may augment whole‐body insulin‐stimulated glucose disposal in healthy young men and part of the change is likely to be explained by muscle hypertrophy. These findings highlight the therapeutic potential of beta2‐agonists for improving insulin sensitivity.Key points While studies in rodents have highlighted beta2‐agonists as a means to augment insulin sensitivity, these studies utilized beta2‐agonists at doses inapplicable to humans.Herein we show that a 4‐week treatment period with daily therapeutic inhalation of beta2‐agonist increases insulin‐stimulated whole‐body glucose disposal in young healthy lean men.This effect was associated with an increase of lean mass but not with changes in GLUT4 and hexokinase II or basal glycogen content in skeletal muscle nor GLUT4 content in abdominal adipose tissue.These findings suggest that the enhanced insulin‐stimulated whole‐body glucose disposal induced by a period of beta2‐agonist treatment in humans, at least in part, is attributed to muscle hypertrophy.Our observations extend findings in rodents and highlight the therapeutic potential of beta2‐agonists to enhance the capacity for glucose disposal and whole‐body insulin sensitivity, providing important knowledge with potential application in insulin resistance.

Effects of Roux-en-Y Gastric Bypass Versus Sleeve Gastrectomy on Body Composition for Patients with a BMI > 35kg/m2 at 1 Year After Surgery.

Effects of Roux-en-Y gastric bypass (RYGB) versus sleeve gastrectomy (SG) on body composition have not been well compared. This meta-analysis aimed to compare changes in fat mass (FM) and lean tissue mass (LTM) for patients with a BMI > 35kg/m2 at 1year after RYGB and SG. PubMed, EMBASE, the Cochrane Library, and ClinicalTrials.gov were searched ending in December 2021 for eligible studies which reported baseline and postsurgical BMI, FM, and LTM. Of 17 eligible studies, 831 patients were included, 484 following RYGB and 347 following SG. Weighted mean differences (WMD) and 95% confidence intervals (CI) were from a random-effects model. For patients with a BMI > 35kg/m2, RYGB resulted in a more substantial reduction of BMI (- 14.13kg/m2 [95%CI - 14.74, - 13.53] versus - 11.96kg/m2 [95%CI - 12.81, - 11.11], P < 0.001) and FM (- 26.22kg [95%CI - 28.31, - 24.12] versus - 21.50kg [95%CI - 25.52, - 17.48], P = 0.042) than SG, and a relatively weaker impact on LTM (- 8.28kg [95%CI - 9.33, - 7.22] versus - 10.12kg [95%CI - 11.55, - 8.68], P = 0.043). This meta-analysis study indicates that RYGB is superior to SG in reducing excess FM for patients with a BMI > 35kg/m2 and seems to be more beneficial when LTM preservation is taken into consideration.