Changes In Muscle Mass Research Articles

The effects of resistance exercise and leucine-enriched essential amino acid supplementation on muscle mass and physical function in post-gastrectomy patients: a pilot randomized controlled trial.

[Purpose] In gastric cancer patients, low muscle mass decreases overall survival and quality of life (QOL). Resistance exercise with leucine-enriched essential amino acid (LEAA) supplementation may prevent muscle mass loss. This study was aimed at determining whether resistance exercise with LEAA supplementation prevents muscle mass loss in post-gastrectomy patients. [Participant and Methods] We conducted a single-center, open-label, randomized controlled pilot trial. Ten participants who underwent gastrectomy were divided into two groups. The intervention group underwent resistance exercise at 70% of one repetition maximum and received a supplement of 3 g of LEAA twice daily for 15 days, while the control group received standard care. We compared changes in muscle mass, physical function (muscle strength and continuous walking distance), and QOL between the groups. [Results] We found good adherence and participation rates in both groups. We failed to detect a significant difference in muscle mass between the groups. The intervention group showed significant improvements in muscle strength and QOL, while the control group showed no significant changes. [Conclusion] We failed to detect a significant difference in muscle mass due to resistance exercise with LEAA supplementation in post-gastrectomy patients. However, resistance exercise with LEAA supplementation might be beneficial for muscle strength recovery and QOL improvements.

Comparison of a Supervised Home-Based Tele-Rehabilitation with Center-Based Pulmonary Rehabilitation: Protocol for a Randomized Non-Inferiority Multicenter Study in Ningxia.

Pulmonary rehabilitation (PR) is an effective intervention for people with chronic obstructive pulmonary disease (COPD). However, fewer than 5% of eligible individuals receive pulmonary rehabilitation, largely due to limited by the accessibility of rehabilitation and difficulties associated with travel and transport. Supervised home-based tele-rehabilitation (SHTR) is an alternative model to center-based pulmonary rehabilitation. We will determine whether supervised home-based tele-rehabilitation is non-inferior to center-based pulmonary rehabilitation. The participants will undergo an 8-week rehabilitation program. Pulmonary rehabilitation comprises four main modules: exercise training, education, nutritional support, and psychological and behavioral interventions. We mainly focus on the module of exercise training and education. The education module includes information on exercise training, nutrition, and psychology, which are presented in an educational booklet provided to each participant. Blinded assessors will evaluate the outcomes at baseline, post-intervention, and 6 months after the intervention. The primary outcome is the change in the 6-minute walking distance. Secondary outcomes will assess changes in the patients' 1-minute sit-to-stand test, maximal inspiratory pressure (MIP), scales (CAT, mMRC, HAD), diaphragm ultrasound (TD, DE, DIF), changes in extrathoracic muscle volume and mass, completion rate of patient exercise prescriptions, occurrence of adverse events, as well as disease exacerbation and rehospitalization rates after rehabilitation and during the 6-month follow-up. In order to improve the accessibility of pulmonary rehabilitation and patient-related outcomes, it is necessary to propose an alternative model of pulmonary rehabilitation. This trial will establish whether a supervised home-based tele-rehabilitation is not inferior to traditional center-based pulmonary rehabilitation. Chinese Clinical Trial Registry ChiCTR2300076969. Registered on October 25, 2023.

Correlation between diaphragmatic function and skeletal muscle mass in chronic obstructive pulmonary disease

Abstract Background Skeletal muscle dysfunction occurs in patients with chronic obstructive pulmonary disease and influences both respiratory and nonrespiratory muscles. This is a very important comorbidity leading to a poor prognosis, including increased mortality and hospitalization. It is the result of a complex combination of functional, metabolic, and anatomical changes that result in suboptimal muscle performance. Objective To identify the correlation between change in skeletal muscle mass (SMM) and diaphragmatic thickness and excursion in chronic obstructive pulmonary disease (COPD) patients. Patients and methods Cross sectional study, comprising of 44 stable COPD patients underwent transthoracic ultrasound assessment of diaphragmatic thickness and excursion, SMM estimation using body sense smart scale machine, and ultrasound estimation of biceps and triceps thickness and then the results were correlated. Results Diaphragmatic thickness and excursion had significant positive correlations with corresponding SMM, biceps thickness and triceps thickness as well as significant negative correlation with smoking pack/years and number of exacerbations in the last year. Conclusions Low SMM is a relevant comorbidity in COPD patients and associated with affected diaphragmatic function as regard thickness and excursion. High Smoking pack/years and high number of exacerbations are significant independent factors that decrease diaphragmatic thickness and excursion, and increased the likelihood of having low SMM. Change in SMM and diaphragmatic function negatively affect the health status represented in the number of exacerbations in the last year.

Type 2 Diabetes Mellitus is a Risk Factor for Skeletal Muscle Loss in the Course of Dietary Treatment for Patients with Metabolic Dysfunction-associated Steatotic Liver Disease.

Objective This study assessed the impact of dietary therapy and reduced body weight on the loss of skeletal muscle in patients with metabolic dysfunction-associated steatotic liver disease (MASLD). Methods This was a single-center retrospective observational study. We enrolled 129 patients with MASLD who had undergone dietary therapy at our facility. We assessed skeletal muscle mass using a bioelectrical impedance analysis (BIA) at the start of dietary treatment and 12 months after the first assessment. Variables related to muscle reduction were analyzed using a logistic regression model. Results One hundred and eighteen cases were analyzed, excluding those with missing data. In the muscle reduction group, there were more subjects with body weight reduction than in the control group (68% and 40%, respectively, p =0.002), and their body mass index (BMI) was decreased (-0.7 kg/m2 and +0.3 kg/m2, respectively, p =0.0003). There was a significant correlation between the changes in the BMI and muscle mass (R =0.48, p <0.0001). We standardized muscle mass change by dividing it by weight change to analyze the severe decrease in muscle mass compared to weight change. A logistic regression analysis revealed that type 2 diabetes mellitus (T2DM) was an independent variable related to severe skeletal muscle loss (odds ratio, 2.69; 95% CI: 1.13-6.42, p =0.03). Conclusion Weight loss is associated with skeletal muscle loss during dietary treatment for MASLD. T2DM is a risk factor for severe skeletal muscle loss.

Anthropometric and laboratory parameter alterations following bimaxillary orthognathic surgery

The aim of this study was to investigate the impact of bimaxillary orthognathic surgery on patients’ anthropometric measures and laboratory parameters. This study was conducted on patients who underwent bimaxillary orthognathic surgery. Anthropometric measurements were collected before surgery (T0) and at intervals of one week (T1), two weeks (T2), one month (T3), and three months (T4) postoperatively, and laboratory parameters at T0 and T4. Data analysis included repeated-measures ANOVA for assessing weight changes, body mass index (BMI) and fat percentage changes, the Friedman test for muscle mass changes, and independent t tests to understand gender-based differences. Significant reductions were observed in weight (mean differences ranging from 2.26 kg to 3.84 kg, 95.00% CI: 1.29 to 4.62, p < 0.01) and BMI (mean differences ranging from 0.76 to 1.32, 95.00% CI: 0.38 to 1.58, p < 0.01) postoperatively at all follow-up points. Fat percentage changes were significant between T0 – T3 (MD = 1.17, 95.00% CI: 0.26 to 2.08, p < 0.05) and T0 - T4 (MD = 1.28, 95.00% CI: 0.14 to 2.43, p < 0.05). Changes in muscle mass were significant until T3 (MD ranging from 71.00 to 107.0, p < 0.01). Also, haemoglobin levels were significantly higher at T0 than T4 (MD = 0.35, 95% CI: 0 to 0.7). These changes showed no significant gender-based differences (p > 0.05). Our study showed that orthognathic surgery prompts temporary changes in body weight, Body Mass Index, and haemoglobin levels. Future research should explore interventions to mitigate these changes and enhance postoperative recovery.

Restoring skeletal muscle mass as an independent determinant of liver fat deposition improvement in MAFLD

AimsCross-sectional studies have demonstrated the association of skeletal muscle mass with metabolic-associated fatty liver disease (MAFLD), while longitudinal data are scarce. We aimed to explore the impact of changes in relative skeletal muscle mass on the MAFLD treatment response.MethodsMAFLD patients undergoing magnetic resonance imaging-based proton density fat fraction for liver fat content (LFC) assessments and bioelectrical impedance analysis before and after treatment (orlistat, meal replacement, lifestyle modifications) were enrolled. Appendicular muscle mass (ASM) was adjusted by weight (ASM/W).ResultsOverall, 256 participants were recruited and divided into two groups: with an ASM/W increase (n=166) and without an ASM/W increase (n=90). There was a great reduction in LFC in the group with an ASM/W increase (16.9% versus 8.2%, P < 0.001). However, the change in LFC in the group without an ASM/W increase showed no significant difference (12.5% versus 15.0%, P > 0.05). △ASM/W Follow-up-Baseline [odds ratio (OR)=1.48, 95% confidence interval (CI) 1.05-2.07, P = 0.024] and △total fat mass (OR=1.45, 95% CI 1.12-1.87, P = 0.004) were independent predictors for steatosis improvement (relative reduction of LFC ≥ 30%). The subgroup analysis showed that, despite without weight loss, decrease in HOMA-IR (OR=6.21, 95% CI 1.28-30.13, P=0.023), △total fat mass Baseline -Follow-up (OR=3.48, 95% CI 1.95-6.21, P <0.001 and △ASM/W Follow-up-Baseline (OR=2.13, 95% CI 1.12-4.05, P=0.022) independently predicted steatosis improvement.ConclusionsASM/W increase and loss of total fat mass benefit the resolution of liver steatosis, independent of weight loss for MAFLD.

Cardiovascular effects of weight loss in old adults with overweight/obesity according to change in skeletal muscle mass.

Patients with overweight/obesity and type 2 diabetes are encouraged to lose weight, but not all losing weight gain better cardiovascular health, especially old adults. The change in skeletal muscle mass (SMM) could be the key that explains the heterogenous cardiovascular effects of weight loss. This study aims to assess whether the cardiovascular effects of weight loss vary for those gaining skeletal muscle along with weight loss. The old adults with overweight/obesity and type 2 diabetes in the Look AHEAD study having muscle measurement from dual-energy X-ray absorptiometry were included. Based on the weight change (WC) and SMM change (SMMC) between baseline and the 4-year follow-up, participants were allocated into three groups-weight gain (WG) group, weight loss with muscle loss (WL-ML) group and weight loss with muscle gain (WL-MG) group. Cox proportional hazards regression was performed to evaluate the cardiovascular risk of those gaining or losing SMM with weight loss compared with those gaining weight. Among the participants with weight loss, the ratio of SMMC/WC was calculated, and the association of SMMC/WC with primary cardiovascular outcome was assessed. A total of 491 participants were included in the study with an average age of 64.56±3.81years old. A total of 47.0% were male and 49.9% were from the intensive lifestyle intervention arm. Based on their WC and SMMC, 43 were assigned to the WG group, 373 to the WL-ML group and 75 to the WL-MG group. Over a follow-up of almost 10years, 97 participants encountered the primary endpoint. The WG group had the highest incidence of 25.59%, the WL-MG group had the lowest incidence of 9.33% and the WL-ML group had 21.18% (P=0.040). In the fourth adjusted Cox model, the WL-MG group achieved significantly decreased odds of the primary endpoint compared with the WG group (hazard ratio [HR] 0.33, 95% confidence interval [CI] [0.12, 0.87], P=0.026), whilst the WL-ML group did not (HR 0.91, 95% CI [0.47, 1.78], P=0.670). Among the participants with weight loss, when SMMC/WC reached around 50%, this HR soared to approximately two-fold. The participants gaining SMM along with weight loss achieved the lowest odds of adverse cardiovascular events, whilst those who lost SMM along with weight loss had comparable cardiovascular risk with those gaining weight. The more muscle lost during weight loss, the greater the harm. The cardiovascular effects of weight loss were modulated by whether the participants gained SMM meanwhile losing weight.

Clinical impact of skeletal muscle mass change during the neoadjuvant chemotherapy period in patients with gastric cancer: An ancillary study of JCOG1002.

Recent studies have revealed that sarcopenia is associated with postoperative complications and poor prognosis. Although neoadjuvant chemotherapy is a promising treatment for gastric cancer, its toxicity may lead to the loss of skeletal muscle mass. This study investigates the changes in skeletal muscle mass during neoadjuvant chemotherapy and its clinical impact on patients with locally advanced gastric cancer. Fifty patients who completed two courses of neoadjuvant chemotherapy followed by surgery were included. Skeletal muscle mass was measured using computed tomography images before and after chemotherapy. The proportion of skeletal muscle mass change (%SMC) during neoadjuvant chemotherapy and its cutoff value was explored using the receiver operating characteristic for the overall survival of patients undergoing R0 resection. Risk factors of skeletal muscle mass loss were also evaluated. Overall, 64% of patients had skeletal muscle mass loss during neoadjuvant chemotherapy (median %SMC -3.4%; range: -18.9% to 10.3%). Multivariable analysis identified older age (≥70years) as an independent predictor of skeletal muscle mass loss (mean [95% confidence interval]: -4.70% [-8.83 to -0.58], p=0.026). Among 43 patients undergoing R0 resection, %SMC <-6.9% was an independent poor prognostic factor for overall survival (hazard ratio, 11.53; 95% confidence interval, 2.78-47.80) and relapse-free survival (hazard ratio 4.54, 95% confidence interval 1.50-13.81). Skeletal muscle mass loss occurs frequently during neoadjuvant chemotherapy for locally advanced gastric cancer and could adversely affect survival outcomes.

Physiological and clinical effects of low-intensity blood-flow restricted resistance exercise compared to standard rehabilitation in adults with knee osteoarthritis–Protocol for a randomized controlled trial

Introduction Osteoarthritis (OA) is a common disease with high socioeconomical costs. In Denmark, standard rehabilitation (SR) consists of a combination of patient education and supervised physical exercise involving a standardized neuromuscular training program. As an evidence-based alternative, high–load (&gt;70% 1RM) resistance training (HIRT) has shown positive rehabilitation effects in knee-OA but may not be tolerated in all patients (~25%) due to knee joint pain. However, low-load resistance training (20–40% 1RM) with concurrent partial blood-flow restriction (BFR) appears to produce effects similar to HIRT yet involving reduced joint pain during and after exercise. The aim is to examine the effect of low-load BFR training compared to SR on pain, thigh muscle mass and muscle function in adults with knee-OA. We hypothesize that 12 weeks of BFR will lead to superior improvements in pain, muscle mass and mechanical muscle function compared to SR. Methods and analysis 90 participants diagnosed with radiographic knee-OA will be randomized to either BFR or SR twice a week for 12 weeks. BFR will consist of two selected lower limb strength exercises performed with an inflated pneumatic occlusion cuff. Intervention procedures in SR consist of a full 8 weeks GLA:D course followed by 4 weeks of team group training. Primary outcome variable is the change in KOOS-Pain subscale from baseline to 12 weeks. Secondary outcome variables are changes in pain sensitivity, functional performance, muscle mass and mechanical muscle function. Intention-to-treat and per-protocol analyses will be conducted. One-way analysis of variance will be performed to evaluate between-group changes. Pre-to-post intervention comparisons will be analyzed using a mixed linear model. Regression analysis will be performed to evaluate potential associations between selected outcome variables.

Energy and nutrient intake in older adults with healthy aging during the Corona Virus Disease 19 pandemic– a cohort study

Background and objectiveLockdown measures implemented amid the COVID-19 pandemic promoted changes in lifestyle, particularly engagement in physical activity/exercise and dietary intake. However, few studies are available investigating the healthy older population, particularly in developing countries. Therefore, the objective of this study was to assess the impact of the COVID-19 pandemic on energy and nutrient intake among older adults with successful aging and to evaluate changes in muscle mass, strength and physical performance. MethodsA cohort study of 38 healthy older adults from a Brazilian geriatrics referral center were assessed at two time points: baseline – up to 1 year prior to the pandemic; and follow-up – an average of 17 months after the pandemic outbreak. Energy and nutrient intake was determined using food recalls and diary records, while muscle mass was calculated based on anthropometric parameters. Maximum hand-grip strength and Short Physical Performance Battery (SPPB) score were also evaluated. ResultsMedian age of participants was 87 years. During the pandemic, intake of protein increased from 52.6g to 63.9g (p=0.013) and micronutrients also increased: vitamin C from 35.4 mg to 76.1mg (p=0.027), vitamin B12 from 2.2mg to 3.1 mg (p=0.045), calcium from 435.1mg to 631.5mg (p<0.001), magnesium from 186.5mg to 198.9 mg (p=0.043), zinc from 5.8 mg to 7.6 mg (p=0.009), iron from 6.9mg to 7.2 mg (p=0.035) and potassium from 1941.6mg to 2115.5 mg (p=0.048). No changes in energy intake or other nutrients were evident. No difference in mass, strength or physical performance was observed during the study period. Overall, 84% of participants remained physically active, although engagement in physical exercise decreased by 50% (p<0.002). ConclusionThe increase in intake of proteins and micronutrients suggests improved diet quality during the pandemic. Engagement in physical exercise decreased significantly, but level of physical activity was maintained. No change in anthropometric parameters, strength or physical performance was evident in the population investigated.

Concordance between changes in calf circumference and muscle mass exists: A narrative literature review

Technological methods such as BIA or DXA are not always accessible in clinical practice, thus GLIM supports the use of calf circumference measurements to examine muscle mass. However, it has not been described if measurements of calf circumference can detect a change in muscle mass to the same degree as the technological methods. The aim of this study was to assess, whether changes in calf circumference can be used as a valid proxy for changes in muscle mass. 10 studies including measurements of muscle mass by calf circumference and technological methods at baseline and follow-up were identified through a narrative literature review. Results were used to determine concordance between measurements. Predominantly concordance between changes in calf circumference and muscle mass assessed by BIA or DXA was reviled. However, the results were not uniform for hospitalized patients or older adults as groups. Thus, uncertainty whether changes in calf circumference can be used as a valid proxy for changes in muscle mass in these groups still exist.

Changes in Lower Extremity Muscle Quantity and Quality in Patients with Subacute Stroke.

To analyze the changes in muscle mass and quality with time on the paretic and non-paretic sides in subacute stroke patients and identify correlations between the variation of muscle mass and quality and lower limb functions. Thirty hemiplegia patients diagnosed with stroke participated in this study. To evaluate poststroke muscle changes, longitudinal measurement of muscle mass and quality was conducted with bilateral lower limbs. The elastic shear modulus was measured using shear wave elastography and muscle thickness (MT) of rectus femoris, vastus intermedius, vastus lateralis (VL), vastus medialis, tibialis anterior, and gastrocnemius (GCM) muscles. Functional evaluation was performed using Berg Balance Scale (BBS), Five Times Sit to Stand Test (FTSST). Follow-up was performed at discharge. The muscle mass and quality were compared according to time. We analyzed whether muscle quantity and quality were related to function. MT demonstrated no significant change with time. The elastic shear modulus increased significantly in the paretic VL and GCM muscles and did not change significantly in the muscles on the non-paretic side. Correlation analysis detected that elastic shear modulus in the VL has a cross-sectional negative relationship between BBS and positive relationship between FTSST. There were significant correlation between variation of FTSST and the variation of the elastic shear modulus in VL. Only paretic VL and GCM muscle quality changed in subacute stroke patients and muscle's property related to lower limb functions. Therefore, the lower extremity requires an approach to muscle quality rather than quantity for subacute stroke patients.

Age-related change in muscle strength, muscle mass, and fat mass between the dominant and non-dominant upper limbs.

Any form of physical activity is recommended for the older adults to maintain their physical function; however, the effect of daily activities on muscle function still needs to be investigated. Humans always use one dominant hand to perform tasks, providing a natural situation for research on the effect of daily activities on muscle function. Five hundred and twenty-six healthy adults were recruited from the community in Beijing. Muscle strength was assessed using a handgrip dynamometer, lean mass, fat mass, bone area and bone mineral content of upper limbs were assessed using dual-energy X ray-absorptiometry. The results were compared between the dominant and non-dominant upper limbs. The dominant upper limb had better muscle strength, lean mass, bone area and bone mineral content than the non-dominant side. The difference in muscle strength and lean mass between the two upper limbs decreased with the advanced age. In older age, fat mass of upper limbs increased in men, but not in women. Daily activities can maintain better muscle function in the dominant upper limb than in the non-dominant side; however, the delaying effect on age-related decline in muscle function was limited.

Effects of male paratroopers' initial body composition on changes in physical performance and recovery during a 20-day winter military field training.

Changes in physiological markers and physical performance in relation to paratroopers' initial body composition were investigated during a 20-day winter military field training (MFT) and the subsequent 10-day recovery period. Body composition, serum hormone concentrations and enzymatic biomarkers, and physical performance of 58 soldiers were measured before, during, and after MFT. Comparisons were done according to soldiers' body fat percentage before MFT between low-fat (<12% body fat) and high-fat (>12% body fat) groups. Correlations between body fat percentage preceding MFT and changes in muscle mass, physical performance, and serum hormone concentrations and enzymatic biomarkers were investigated. It was hypothesized that soldiers with a higher fat percentage would have smaller decrements in muscle mass, physical performance, and serum testosterone concentration. The change in muscle and fat mass was different between groups (p <0.001) as the low-fat group lost 0.8kg of muscle mass and 2.0kg of fat mass, while there was no change in muscle mass and a loss of 3.7kg of fat mass in the high-fat group during MFT. Fat percentage before MFT correlated with the changes in muscle mass (R2=0.26, p <0.001), serum testosterone concentration (R2=0.22, p <0.001), and evacuation test time (R2=0.10, p <0.05) during MFT. The change in muscle mass was correlated with the changes in evacuation test time (R2=0.11, p <0.05) and countermovement jump test results (R2=0.13, p <0.01) during MFT. Soldiers with a higher initial fat percentage lost less muscle mass, and had smaller decrements in some aspects of physical performance, as well as in serum testosterone concentration during MFT.

The metabolic effects of intermittent versus continuous feeding in critically ill patients

Intermittent (or bolus) feeding regimens in critically ill patients have been of increasing interest to clinicians and scientists. Changes in amino acid, fat and carbohydrate metabolites over time might yet deliver other benefits (e.g. modulation of the circadian rhythm and sleep, and impacts on ghrelin secretion, insulin resistance and autophagy). We set out to characterise these changes in metabolite concentration. The Intermittent versus Continuous Feeding in Critically Ill paitents study (NCT02358512) was an eight-centre single-blinded randomised controlled trial. Patients were randomised to received a continuous (control arm) or intermittent (6x/day, intervention arm) enteral feeding regimen. Blood samples were taken on trial days 1, 7 and 10 immediately before and 30 min after intermittent feeds, and at equivalent timepoints in the control arm. A pre-planned targeted metabolomic analysis was performend using Nuclear Resonance Spectroscopy. Five hundred and ninety four samples were analysed from 75 patients. A total of 24 amino acid-, 19 lipid based-, and 44 small molecule metabolite features. Across the main two axes of variation (40–60% and 6–8% of variance), no broad patterns distinguished between intermittent or continuous feeding arms, across intra-day sampling times or over the 10 days from initial ICU admission. Logfold decreases in abundance were seen in metabolites related to amino acids (Glutamine − 0.682; Alanine − 0.594), ketone body metabolism (Acetone − 0.64; 3-Hydroxybutyric Acid − 0.632; Acetonacetic Acid − 0.586), fatty acid (carnitine − 0.509) and carbohydrate metabolism ( Maltose − 0.510; Citric Acid − 0.485). 2–3 Butanediol, a by-product of sugar-fermenting microbial metabolism also decreased (− 0.489). No correlation was seen with change in quadriceps muscle mass for any of the 20 metabolites varying with time (all p > 0.05). Increasing severity of organ failure was related to increasing ketone body metabolism (3 Hydroxybutyric Acid-1 and − 3; p = 0.056 and p = 0.014), carnitine deficiency (p = 0.002) and alanine abundancy (p − 0.005). A 6-times a day intermittent feeding regimen did not alter metabolite patterns across time compared to continuous feeding in critically ill patients, either within a 24 h period or across 10 days of intervention. Future research on intermittent feeding regimens should focus on clinical process benefits, or extended gut rest and fasting.

Improved endurance capacity of diabetic mice during SGLT2 inhibition: Role of AICARP, an AMPK activator in the soleus.

Diabetes is associated with an increased risk of deleterious changes in muscle mass and function or sarcopenia, leading to physical inactivity and worsening glycaemic control. Given the negative energy balance during sodium-glucose cotransporter-2 (SGLT2) inhibition, whether SGLT2 inhibitors affect skeletal muscle mass and function is a matter of concern. However, how SGLT2 inhibition affects the skeletal muscle function in patients with diabetes remains insufficiently explored. We aimed to explore the effects of canagliflozin (CANA), an SGLT2 inhibitor, on skeletal muscles in genetically diabetic db/db mice focusing on the differential responses of oxidative and glycolytic muscles. Db/db mice were treated with CANA for 4weeks. We measured running distance and handgrip strength to assess skeletal muscle function during CANA treatment. At the end of the experiment, we performed a targeted metabolome analysis of the skeletal muscles. CANA treatment improved the reduced endurance capacity, as revealed by running distance in db/db mice (414.9±52.8 vs. 88.7±22.7m, P<0.05). Targeted metabolome analysis revealed that 5-aminoimidazole-4-carboxamide-1-β-D-ribofuranosyl 5'-monophosphate (AICARP), a naturally occurring AMP-activated protein kinase (AMPK) activator, increased in the oxidative soleus muscle (P<0.05), but not in the glycolytic extensor digitorum longus muscle (P=0.4376), with increased levels of AMPK phosphorylation (P<0.01). This study highlights the potential role of the AICARP/AMPK pathway in oxidative rather than glycolytic skeletal muscles during SGLT2 inhibition, providing novel insights into the mechanism by which SGLT2 inhibitors improve endurance capacity in patients with type 2 diabetes.

Vascular dysfunction and the age-related decline in critical power.

Ageing results in lower exercise tolerance, manifested as decreased critical power (CP). We examined whether the age-related decrease in CP occurs independently of changes in muscle mass and whether it is related to impaired vascular function. Ten older (63.1±2.5 years) and 10 younger (24.4±4.0 years) physically active volunteers participated. Physical activity was measured with accelerometry. Leg muscle mass was quantified with dual X-ray absorptiometry. The CP and maximum power during a graded exercise test (PGXT ) of single-leg knee-extension exercise were determined over the course of four visits. During a fifth visit, vascular function of the leg was assessed with passive leg movement (PLM) hyperaemia and leg blood flow and vascular conductance during knee-extension exercise at 10W, 20W, slightly below CP (90% CP) and PGXT . Despite not differing in leg lean mass (P=0.901) and physical activity (e.g., steps per day, P=0.735), older subjects had ∼30% lower mass-specific CP (old=3.20±0.94Wkg-1 vs. young=4.60±0.87Wkg-1 ; P<0.001). The PLM-induced hyperaemia and leg blood flow and/or conductance were blunted in the old at 20W, 90% CP and PGXT (P<0.05). When normalized for leg muscle mass, CP was strongly correlated with PLM-induced hyperaemia (R2 =0.52; P<0.001) and vascular conductance during knee-extension exercise at 20W (R2 =0.34; P=0.014) and 90% CP (R2 =0.39; P=0.004). In conclusion, the age-related decline in CP is not only an issue of muscle quantity, but also of impaired muscle quality that corresponds to impaired vascular function.

Abstract 15785: Effects of Empagliflozin on Fatty Acid Binding Protein 4 and Body Composition in Patients Without Diabetes but With Risk Factors for Adverse Cardiac Remodeling From the Empa-Heart 2 Cardiolink-7 Randomized Clinical Trial

Background: Prevention of the progression from stage B to C heart failure is an unmet need. Increased fat composition in skeletal muscle is one of the mechanisms associated with heart failure with preserved ejection fraction. Fatty acid binding protein 4 (FABP4) is known to facilitate the transport of fatty acid to tissue mitochondria for lipid oxidation. Knockdown of FABP4 gene is associated with increased body weight and fat mass in animal models. We sought to determine if Sodium-glucose co-transporter 2 (SGLT2) inhibition with empagliflozin leads to change in blood FABP4 levels and improvement in body composition in patients without diabetes and significant heart failure but with risk factors for adverse cardiac remodeling. Hypothesis: Empagliflozin increases blood FABP4 concentration and lowers body fat composition without changes in skeletal muscle mass. Methods: A total of 42 individuals between 40 and 80 years of age without diabetes but with risk factors for adverse cardiac remodeling were randomized to empagliflozin (10 mg/day; n=21) and placebo (n=21) groups for 6 months. Body composition parameters measured by bio-impedance analysis (InBody-720) included body weight (BW), skeletal muscle mass (SMM) and body fat mass (BFM) at baseline and 6 months follow up. Blood FABP4 concentrations were measured at the same time points. Results: There were no significant differences between two groups in baseline characteristics, BW, SMM, BFM, or FABP4. From baseline to 6 months, empagliflozin compared to placebo significantly increased blood FABP4 concentrations (6067.3 ± 7591.4 pg/ml vs 2714.9 ± 11232.6 pg/ml, p = 0.002), but decreased BW (-1.19 ± 1.01 kg vs 0.34 ± 2.59 kg, p = 0.018) and BFM (-0.68 ± 1.27 kg vs 0.53 ± 2.01 kg, p = 0.024). However, empagliflozin did not significantly affect changes in SMM from baseline to 6 months (-4.01 ± 0.70 kg vs -0.17 ± 0.96 kg, p = 0.387). Conclusions: SGLT2 inhibition with empagliflozin, in patients with neither diabetes nor significant heart failure but with risk factors for adverse cardiac remodeling, increased blood FABP4 concentrations and ameliorated BW and body fat composition with no effect on skeletal muscle mass following 6 months of treatment.

Abstract 16566: A Lifestyle-Integrated Resistance-Based Exercise Intervention for Sarcopenic Patients With Coronary Artery Disease: A Pilot Randomized Controlled Trial

Introduction: Sarcopenia is an important prognostic indicator for patients with coronary artery disease (CAD). No study has explored the effects of resistance-based exercise on sarcopenic patients with CAD. Hypothesis: Patients who receive the lifestyle-integrated resistance-based exercise intervention would have better physical performance, skeletal muscle mass, muscle strength, cardiac-related functional status, health-related quality of life (HRQoL) and psychological distress after the intervention than those who receive usual care. Aims: To examine the feasibility and preliminary effects of the strength-building lifestyle-integrated intervention among sarcopenic CAD patients on physical performance, skeletal muscle mass, muscle strength, cardiac-related functional status, HRQoL and psychological distress. Methods: This two-arm pilot randomized controlled trial recruited community-dwelling older CAD patients with sarcopenia. Patients in the intervention group received the 12-week individualized, progressive, low-to-moderate intensity resistance-based exercise intervention delivered through in-person and online supervised approach. The control group received usual care. Results: Thirty-eight participants (mean age: 69.0 ± 4.9 years) were randomized into the intervention (n = 21) or control (n = 17) group. The intervention was feasible and acceptable. The lost to follow-up rate was 7.9%, and the overall attendance was 92%. No adverse events were recorded. The intervention group showed significantly greater improvement in HRQoL (β = 0.417, 95%CI: 0.036 - 0.798, p = 0.032) and functional status (β = -1.342, 95%CI: -2.808 - -0.124, p = 0.043) than the control group at the immediate post-intervention. No significant between-group changes in physical performance, muscle mass and strength, and psychological distress were detected. Conclusions: The intervention is feasible and acceptable for CAD patients. It improves patients HRQoL and functional status. A full-scale randomized controlled trial is warranted to investigate its effects.

Evaluation of sex-based differences in resistance exercise training-induced changes in muscle mass, strength, and physical performance in healthy older (≥60 y) adults: A systematic review and meta-analysis.

The objective of this systematic review and meta-analysis was to determine if there are sex-based differences in adaptations to resistance exercise training in healthy older adults. Following the screening process, data from 36 studies comparing older males and females (602 males; 703 females; ≥60 years of age) for changes in skeletal muscle size, muscle strength, and/or physical performance following the same resistance exercise training intervention were extracted. Mean study quality was 16/29 (modified Downs and Black checklist), considered moderate quality. Changes in absolute upper-body (Effect Size [ES] = 0.81 [95% CI 0.54, 1.09], P<0.001), and lower-body (ES = 0.40 [95% CI 0.24, 0.56], P<0.001) strength were greater in older males than females. Alternatively, changes in relative upper-body (ES = -0.46 [95% CI -0.77, -0.14], P<0.01), and lower-body (ES = -0.24 [95% CI -0.42, -0.06], P<0.01) strength were greater in older females than males. Changes in absolute, but not relative, whole-body fat-free mass (ES = 0.18 [95% CI 0.04, 0.33], P<0.05) were greater in older males than females. There were no sex-based differences for absolute or relative changes in limb muscle size, muscle fiber size, or physical performance.