Effects of branched-chain amino acid-rich supplementation on EWGSOP2 criteria for sarcopenia in older adults: a systematic review and meta-analysis

An Ontology-Based Decision Support System for Tailored Clinical Nutrition Recommendations for Patients With Chronic Obstructive Pulmonary Disease: Development and Acceptability Study

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a chronic condition among the main causes of morbidity and mortality worldwide, representing a burden on health care systems. Scientific literature highlights that nutrition is pivotal in respiratory inflammatory processes connected to COPD, including exacerbations. Patients with COPD have an increased risk of developing nutrition-related comorbidities, such as diabetes, cardiovascular diseases, and malnutrition. Moreover, these patients often manifest sarcopenia and cachexia. Therefore, an adequate nutritional assessment and therapy are essential to help individuals with COPD in managing the progress of the disease. However, the role of nutrition in pulmonary rehabilitation (PR) programs is often underestimated due to a lack of resources and dedicated services, mostly because pneumologists may lack the specialized training for such a discipline.

OBJECTIVE

This work proposes a novel knowledge-based decision support system to support pneumologists in considering nutritional aspects in PR. The system provides clinicians with patient-tailored dietary recommendations leveraging expert knowledge.

METHODS

The expert knowledge-acquired from experts and clinical literature-was formalized in domain ontologies and rules, which were developed leveraging the support of Italian clinicians with expertise in the rehabilitation of patients with COPD. Thus, by following an agile ontology engineering methodology, the relevant formal ontologies were developed to act as a backbone for an application targeted at pneumologists. The recommendations provided by the decision support system were validated by a group of nutrition experts, whereas the acceptability of such an application in the context of PR was evaluated by pneumologists.

RESULTS

A total of 7 dieticians (mean age 46.60, SD 13.35 years) were interviewed to assess their level of agreement with the decision support system's recommendations by evaluating 5 patients' health conditions. The preliminary results indicate that the system performed more than adequately (with an overall average score of 4.23, SD 0.52 out of 5 points), providing meaningful and safe recommendations in compliance with clinical practice. With regard to the acceptability of the system by lung specialists (mean age 44.71, SD 11.94 years), the usefulness and relevance of the proposed solution were extremely positive-the scores on each of the perceived usefulness subscales of the technology acceptance model 3 were 4.86 (SD 0.38) out of 5 points, whereas the score on the intention to use subscale was 4.14 (SD 0.38) out of 5 points.

CONCLUSIONS

Although designed for the Italian clinical context, the proposed system can be adapted for any other national clinical context by modifying the domain ontologies, thus providing a multidisciplinary approach to the management of patients with COPD.

Associations between sarcopenia and circulating branched-chain amino acids: a cross-sectional study over 100,000 participants

BACKGROUND

Emerging evidence suggests that alterations in BCAA metabolism may contribute to the pathogenesis of sarcopenia. However, the relationship between branched-chain amino acids (BCAAs) and sarcopenia is incompletely understood, and existing literature presents conflicting results. In this study, we conducted a community-based study involving > 100,000 United Kingdom adults to comprehensively explore the association between BCAAs and sarcopenia, and assess the potential role of muscle mass in mediating the relationship between BCAAs and muscle strength.

METHODS

Multivariable linear regression analysis examined the relationship between circulating BCAAs and muscle mass/strength. Logistic regression analysis assessed the impact of circulating BCAAs and quartiles of BCAAs on sarcopenia risk. Subgroup analyses explored the variations in associations across age, and gender. Mediation analysis investigated the potential mediating effect of muscle mass on the BCAA-muscle strength relationship.

RESULTS

Among 108,017 participants (mean age: 56.40 ± 8.09 years; 46.23% men), positive associations were observed between total BCAA, isoleucine, leucine, valine, and muscle mass (beta, 0.56-2.53; p < 0.05) and between total BCAA, leucine, valine, and muscle strength (beta, 0.91-3.44; p < 0.05). Logistic regression analysis revealed that increased circulating valine was associated with a 47% reduced sarcopenia risk (odds ratio = 0.53; 95% confidence interval = 0.3-0.94; p = 0.029). Subgroup analyses demonstrated strong associations between circulating BCAAs and muscle mass/strength in men and individuals aged ≥ 60 years. Mediation analysis suggested that muscle mass completely mediated the relationship between total BCAA, and valine levels and muscle strength, partially mediated the relationship between leucine levels and muscle strength, obscuring the true effect of isoleucine on muscle strength.

CONCLUSION

This study suggested the potential benefits of BCAAs in preserving muscle mass/strength and highlighted muscle mass might be mediator of BCAA-muscle strength association. Our findings contribute new evidence for the clinical prevention and treatment of sarcopenia and related conditions involving muscle mass/strength loss.

Serum branched-chain amino acid levels are associated with fracture risk in Japanese women

AIM

Branched-chain amino acids (BCAAs) have been shown to exert beneficial effects on muscle and bone metabolism; however, no studies to date have investigated whether BCAAs have beneficial effects on bone fractures. Herein, we aim to prospectively investigate the relationship between serum BCAA concentrations and the occurrence of vertebral fractures (VFs) in Japanese women.

METHODS

During the observation period (7.5 ± 6.1 years), 188 of 983 participants experienced VF. Kaplan-Meier analyses were conducted to examine time-dependent variations in the vertebral compression fracture occurrence rate. Patients were stratified into quartiles based on serum BCAA concentration for this analysis.

RESULTS

The analysis results indicated that the group with the lowest BCAA level developed VFs significantly earlier and with a higher frequency than the other groups (P < 0.001). A Cox proportional hazards model showed that BCAA concentration was a significant risk factor for incident fracture, even after adjusting for possible confounding factors. A series of multiple regression analyses were performed to identify factors related to serum BCAA concentration, with the results identifying levels of glycated hemoglobin (P < 0.001), adiponectin (P < 0.001), and NOx (P = 0.011) as significant factors associated with serum BCAA.

CONCLUSIONS

Overall, the present study revealed that a lower serum BCAA level was an independent risk factor for incident VF in postmenopausal women. Geriatr Gerontol Int 2024; 24: 603-608.

Aging-Related Sarcopenia: Metabolic Characteristics and Therapeutic Strategies

The proportion of the elderly population is gradually increasing as a result of medical care advances, leading to a subsequent surge in geriatric diseases that significantly impact quality of life and pose a substantial healthcare burden. Sarcopenia, characterized by age-related decline in skeletal muscle mass and quality, affects a considerable portion of older adults, particularly the elderly, and can result in adverse outcomes such as frailty, fractures, bedridden, hospitalization, and even mortality. Skeletal muscle aging is accompanied by underlying metabolic changes. Therefore, elucidating these metabolic profiles and specific mechanisms holds promise for informing prevention and treatment strategies for sarcopenia. This review provides a comprehensive overview of the key metabolites identified in current clinical studies on sarcopenia and their potential pathophysiological alterations in metabolic activity. Besides, we examine potential therapeutic strategies for sarcopenia from a perspective focused on metabolic regulation.

Impact of body composition on the prognosis of hepatocellular carcinoma patients treated with transarterial chemoembolization: A systematic review and meta-analysis

Objectives

To summarize current evidence about the influence of body composition on the prognosis of patients with hepatocellular carcinoma (HCC) after transarterial chemoembolization (TACE) treatment.

Methods

Public databases were systematically searched to identify relevant studies published from the inception of the database up to May 2023. Studies that evaluated the association between body composition and clinical outcomes in HCC patients who underwent TACE were included. A pre-designed table was applied to summarize relevant information. Meta-analysis was performed to estimate the association of body composition with overall survival.

Results

Fourteen studies were included in this review, including 3631 patients (sample size range: 56-908, median 186). All body composition measurements (including skeletal muscle area, visceral and subcutaneous adipose area, and bone mineral density) were based on computer tomography. The commonly used parameter was skeletal muscle index at 3rd lumbar vertebra level (8/14). Three studies evaluated the correlations of body composition changes with the prognosis after TACE. Most studies (12/14) identified body composition parameters as an independent indicator for overall survival, progression-free survival, and treatment response rate. The hazard ratio of different body composition parameters ranged from 1.01 to 2.88, and hazard ratio of body composition changes ranged from 1.88 to 5.93. The pooled hazard ratio of sarcopenia for overall survival was 1.38 (95 %CI: 1.20-1.58).

Conclusions

Body composition seems to be an important prognostic factor for a poorer clinical outcome after TACE treatment in patients with hepatocellular carcinoma. Future prospective studies with a larger sample size are required to confirm these findings.

Registration study

This study has been prospectively registered at the PROSPERO platform (https://www.crd.york.ac.uk/prospero/) with the registration No. CRD42022345602.

Nutrition Interventions on Muscle-Related Components of Sarcopenia in Females: A Systematic Review of Randomized Controlled Trials

Sarcopenia is a skeletal muscle disease categorized by low muscle strength, muscle quantity or quality, and physical performance. Sarcopenia etiology is multifaceted, and while resistance training is widely agreed upon for prevention and treatment, disease progression is also highly related to poor diet. The incidence of sarcopenia appears sex-specific and may be increased in females, which is problematic because dietary quality is often altered later in life, particularly after menopause. Identifying effective nutrition or supplementation interventions could be an important strategy to delay sarcopenia and related comorbidities in this vulnerable population. This systematic review examined randomized controlled trials (RCTs) of nutrition strategies on muscle-related components of sarcopenia in middle-aged and older females. A protocol was registered (PROSPERO CRD42022382943) and a systematic search of MEDLINE and CINAHL was undertaken. RCTs from 2013 to 2023 that assessed nutrition-only interventions on muscle mass, muscle strength, and physical function in female participants were included. Fourteen RCTs were included based on selection criteria. Study designs and interventions were heterogeneous in supplementation type and amount, age, and duration. Six RCTs reported beneficial effects of protein, Vitamin D, Vitamin D and Magnesium (Mg), and fish oil on muscle protein synthesis, muscle strength, and/or muscle function. Eight studies that examined various protein interventions, VitD alone, Mg alone, and dairy derivatives did not demonstrate any effect. Exercise appeared to modulate results in several studies. Nutrition interventions alone are likely to have a limited but positive effect on muscle-related components of sarcopenia in females. Current evidence suggests that a combination of dietary intervention and exercise is likely to be key to preventing and treating sarcopenia in middle aged and older females and there is a need for well-designed nutrition based studies in this population.

Age Is Just a Number: Progress and Obstacles in the Discovery of New Candidate Drugs for Sarcopenia

Sarcopenia is a disease characterized by the progressive loss of skeletal muscle mass and function that occurs with aging. The progression of sarcopenia is correlated with the onset of physical disability, the inability to live independently, and increased mortality. Due to global increases in lifespan and demographic aging in developed countries, sarcopenia has become a major socioeconomic burden. Clinical therapies for sarcopenia are based on physical therapy and nutritional support, although these may suffer from low adherence and variable outcomes. There are currently no clinically approved drugs for sarcopenia. Consequently, there is a large amount of pre-clinical research focusing on discovering new candidate drugs and novel targets. In this review, recent progress in this research will be discussed, along with the challenges that may preclude successful translational research in the clinic. The types of drugs examined include mitochondria-targeting compounds, anti-diabetes agents, small molecules that target non-coding RNAs, protein therapeutics, natural products, and repositioning candidates. In light of the large number of drugs and targets being reported, it can be envisioned that clinically approved pharmaceuticals to prevent the progression or even mitigate sarcopenia may be within reach.

Can Leucine Supplementation Improve Frailty Index Scores?

Sarcopenia and frailty are important conditions that become increasingly prevalent with age. There is partial overlap between the two conditions, especially in terms of the physical aspects of the frailty phenotype: low grip strength, gait speed, and muscle mass. This study examined whether administration of the essential branched-chain amino acid leucine, besides improving sarcopenia, may reduce frailty assessed by frailty index (FI) in older institutionalized people living in nursing homes. We conducted a secondary analysis of a placebo-controlled, randomized, double-blind design study (ClinicalTrials.gov NCT03831399). The study included fifty males and females aged 65 and over who were living in nursing homes and did not have dementia. The participants were randomized to a parallel group intervention of 13 weeks' duration, with a daily intake of leucine (6 g/day) or placebo (lactose, 6 g/day). The outcome of this study was to evaluate whether there was a change in the level of a 95 item FI compared to the baseline and to compare the effect of the leucine group versus the placebo group. A significant inverse correlation was found between FI and performance of the activities of daily life, cognitive function, gait and balance, muscle function parameters, and nutritional status (p < 0.001 in all cases). There were no statistically significant differences in FI levels at baseline (placebo group FI 0.27 ± 0.08 and leucine group FI 0.27 ± 0.10) and at the 13 week follow-up (placebo group FI 0.28 ± 0.10 and leucine group FI 0.28 ± 0.09). There were also no significant differences between the leucine and placebo groups in the mean FI difference between baseline and follow-up (p = 0.316, Cohen's d: 0.04). This pilot study showed that a nutritional supplementation with leucine did not significantly modify the frailty index in older nursing home residents.

Association between sarcopenia with incident cardio-cerebrovascular disease: A systematic review and meta-analysis

Sarcopenia is an age-associated skeletal muscle disease characterized by the progressive loss of muscle mass and function. The objective of this systematic review and meta-analysis was to evaluate the associations between sarcopenia and cardio-cerebrovascular disease (CCVD). A comprehensive search of the PubMed/Medline, Embase, Web of Science, Scopus, and Cochrane Library databases was conducted from their inception to April 1st, 2023. A total of eight cross-sectional studies involving 63,738,162 participants met the inclusion criteria. Pooled estimates of odds ratios (ORs) were calculated using random-effects models. The findings demonstrated a significant association between sarcopenia and an increased risk of CCVD (OR: 1.33, 95% CI: 1.18 - 1.50, I2 = 1%; p < 0.001). Subgroup analyses indicated that sarcopenia was associated with a 1.67-fold increase in the risk of stroke and a 1.31-fold increase in the risk of CVD. Four studies included in this review examined the association between sarcopenic obesity and the risk of CCVD, and the results revealed that sarcopenic obesity was associated with a higher risk of CCVD (OR: 1.64, 95% CI: 1.08 - 2.49, I2 = 69%; p < 0.001). Meta-regressions and sensitivity analyses consistently supported the robustness of the overall findings. In conclusion, sarcopenia and sarcopenic obesity are significantly associated with an elevated risk of developing CCVD. However, further prospective cohort studies are warranted to validate this relationship while controlling for confounding factors.

Non-pharmacological interventions for community-dwelling older adults with possible sarcopenia or sarcopenia: a scoping review

BACKGROUND

Sarcopenia is a progressive, age-related muscle disease that, if left untreated, imposes significant personal, social, and economic burdens.

OBJECTIVE

To compile and document the nature and extent of existing studies exploring non-pharmacological interventions as a strategy to prevent or treat possible sarcopenia or sarcopenia in community-dwelling older adults.

METHOD

Thirteen databases were searched up from January 2010 to March 2023 and filters were limited to English and Chinese language. Studies with older adults (≥60 y) in the community were included. The review was conducted and reported according to the PRISMA-ScR guidance and seven stages of methodology framework. A descriptive synthesis of trial characteristics and effectiveness was conducted.

RESULTS

A total of 59 studies were included in the analysis. Most studies were RCTs. Few studies enrolled older adults with possible sarcopenia. The 70-79 age group has been studied more than any other age group. Six intervention types were identified, including exercise-only, nutrition-only, health education-only, traditional Chinese medicine-only, multicomponent intervention and control type. Majority of exercise-only interventions received resistance-based exercise. In nutrition-only category, overall food intervention or nutrients intervention was more than dietary pattern. Moreover, exercise plus nutrition was the main sub-type in multicomponent interventions. Health education-only and traditional Chinese medicine-only interventions were less frequently identified. Most studies had high and moderate compliance.

CONCLUSION

There is evidence for the effectiveness of exercise and exercise plus nutrition interventions in improving muscle strength and physical performance, whereas the effectiveness of other intervention types or their combinations requires additional research.

SCOPING REVIEW REGISTRATION

Open Science Framework (OSF) Registration DOI 10.17605/OSF.IO/RK3TE.

Branched-chain amino acids plus vitamin D supplementation promote increased muscle strength following lumbar surgery for lumbar spinal stenosis: a randomized trial

BACKGROUND CONTEXT

Adequate nutrition is essential to address the surgical stress response and mitigate loss of muscle mass, strength, and functionality in older adults with lumbar spinal stenosis (LSS). However, it is unknown whether amino acids and/or vitamin D are beneficial in older adults following lumbar surgery for LSS.

PURPOSE

To evaluate whether branched-chain amino acids (BCAA) plus vitamin D supplementation could attenuate the loss of muscle mass and strength, accelerate the return of functional mobility, and improve clinical outcomes following lumbar surgery for LSS.

STUDY DESIGN/SETTING

A single-center, single-blind randomized controlled trial.

PATIENT SAMPLE

Eighty patients who received lumbar surgery for LSS.

OUTCOME MEASURES

The primary outcome was the Zurich claudication questionnaire (ZCQ), and secondary outcomes included knee muscle strength, muscle mass measured by bioelectrical impedance analysis, gait speed and a timed up-and-go test (TUG) at 12 weeks postoperatively. Follow-up assessment was performed for the ZCQ at 52 weeks postoperatively.

METHODS

Patients ingested the supplementation (BCAA group: BCAA plus vitamin D, Nonamino acid group: nonamino acid) twice daily for 3 weeks from the day after surgery, and received two hours of postoperative inpatient rehabilitation 5 times a week.

RESULTS

No significant differences were observed in the mean changes on the ZCQ between the two groups at 12 weeks and 52 weeks. At 2 weeks postoperatively, the nonamino acid group showed significant deterioration compared with the BCAA group for strengths of knee extensor and knee flexor (p < .01). At 12 weeks, the BCAA group showed significant improvements in knee extensor strength and knee flexor strength compared with the nonamino acid group (p <.01). There were no significant differences in mean changes of muscle mass, maximum gait speed, and TUG at 12 weeks between two groups.

CONCLUSIONS

BCAA plus vitamin D supplementation did not improve LSS-related clinical outcomes after lumbar surgery for LSS, even though muscle strength increased. Future studies should focus on long-term outcomes for muscle mass and physical function, including development of sarcopenia and frailty.

Eicosapentaenoic acid and branched-chain amino acids fortified complete nutrition drink improved muscle strength in older individuals with inadequate protein intake

Background

Elevated inflammation and negative nutritional balance contribute to sarcopenia, a progressive loss of muscle mass, strength, and function. This study investigated the effect of energy supplementation and the combination of anti-inflammatory factor (eicosapentaenoic acid; EPA) and muscle-synthesis promotor (branched-chain amino acids; BCAA) on body composition, muscle, and inflammatory biomarkers in elderly with inadequate protein intake.

Methods

A randomized blinded placebo-controlled trial was conducted on 84 elderly with inadequate protein intake. The participants were randomly assigned into four groups receiving a complete nutrition drink; (1) control formula, (2) fortified with 2.2 g EPA, (3) with 2.2 g EPA and 5 g BCAA (2:1:1 of Leu: Ile: Val), and (4) with 2.2 g EPA plus 5g BCAA (4:1:1 of Leu: Ile: Val). Each subject consumed two sachets of the drink to gain 500 kcal/day and performed arm muscle exercises for 3 weeks. Body compositions and handgrip strength were measured using BIA and a dynamometer, respectively. Plasma EPA and BCAA levels were determined using LC-MS/MS to ensure compliance. Muscle protein biomarkers including histidine, β-alanine, and carnosine were measured using LC-MS/MS. Serum inflammatory (IL-6) and anti-inflammatory cytokines (IL-10) were measured by using ELISA.

Results

No symptoms and signs of adverse events were observed. The right arm muscle mass and handgrip strength were significantly increased after consuming a complete nutrition drink fortified with EPA + BCAA 2:1:1 and 4:1:1 of Leu: Ile: Val (p < 0.05 and p < 0.01, respectively. Consistently, consuming such combinatory formula non-significantly elevated carnosine with reduced histidine, and increased IL-10 with decreased IL-6. All relevant intervention groups showed a significant increase in plasma levels of BCAA and EPA.

Conclusion

Consuming a complete nutrition drink fortified with 2.2g EPA and 5g BCAA 2:1:1 or 4:1:1 of Leu: Ile: Val for 3 weeks may increase right arm muscle mass and strength in elderly with inadequate protein intake. The tendency of increased dipeptide (carnosine)/decreased free amino acid (histidine) suggests a shift toward muscle protein synthesis. The trend of decreased inflammatory/increased anti-inflammatory cytokines suggests an anti-inflammatory effect. Future long-term studies are warranted to confirm the combinatory effect of BCAA and EPA in the prevention of sarcopenia.

Clinical trial registration

Thailand Clinical Trial Registry No. TCTR20230116005.

Nutritional Care Practices in Geriatric Rehabilitation Facilities across Europe: A Cross-Sectional Study

Many patients in geriatric rehabilitation (GR) are physically frail at the time of admission and suffer from malnutrition and sarcopenia, which may worsen rehabilitation outcomes. This study aims to obtain insight into the current nutritional care practices in GR facilities across Europe.

METHODS

In this cross-sectional study, a questionnaire focused on nutritional care practices in GR was distributed across experts in EUGMS member countries. Data were analyzed by using descriptive statistics.

RESULTS

In total, 109 respondents working in 25 European countries participated, and the results showed that not all GR patients were screened and treated for malnutrition, and not all participants used (inter)national guidelines when performing nutritional care. The results also showed variations across European geographical areas related to screening and treatment of malnutrition, sarcopenia, and frailty. Even though the participants underlined the importance of dedicating time to nutritional care, they experienced barriers in its implementation, which were mostly due to a lack of resources.

CONCLUSION

As malnutrition, sarcopenia, and frailty are often present in patients admitted to GR, in addition to being interrelated, it is recommended to develop an integrated approach to screening and treatment of all three clinical problems.

Efficacy and tolerability of a specific blend of amino acids in patients with anorexia nervosa treated in a hospital setting: study protocol for a randomized controlled trial

BACKGROUND

Specific blends of essential amino acids (EAA) containing a high percentage of branched-chain amino acids preserves mitochondrial metabolism and higher physical resistance in elderly mice, increasing their survival and improving physical performance and cognitive functions in malnourished elderly patients. However, no study has been yet done on patients with anorexia nervosa (AN) who regain weight with specialized intensive treatment. The present study aims to evaluate the efficacy of supplementation with EAA on the change in lean body mass (LBM) and other physical and psychological outcomes in patients with AN who are undergoing specialist treatment for eating disorders.

METHODS

This is a 13-week randomized, double-blind, placebo-controlled study. Patients will be randomized to either a mixture of a complex blend of EAA and intermediates of the tricarboxylic acid (TCA) cycle (citrate, malate, succinate) supplementation (or placebo) upon admission at the intensive residential and day-hospital treatment for eating disorders. Ninety-two participants with AN aged 16-50 years will be recruited from a specialized intensive treatment of eating disorders. Double-blind assessment will be conducted at baseline (T0) and the end of the 13 weeks of treatment (T1). The study's primary aim is to evaluate the efficacy of supplementation with EAA and TCA intermediates on the change in lean body mass (LBM) with weight restoration in patients with AN who are undergoing specialist treatment for eating disorders. The secondary aims of the study are to assess the effect of dietary supplementation on physical fitness, weight restoration, modification of AN and general psychopathology, and psychosocial impairment.

DISCUSSION

The study's results will inform researchers and clinicians on whether supplementing a mixture of EAA and TCA cycle intermediates will improve the increase of LBM and other important physical and psychological outcomes in patients with AN who regain weight with specialized intensive treatment.

TRIAL REGISTRATION

NCT, NCT05290285. Registered on 22 March 2022.

The Evaluation of Videos about Branched-Chain Amino Acids Supplements on YouTube™: A Multi-Approach Study

Branched-chain amino acids (BCAAs) are one of the most controversial ergogenic aids in terms of effectiveness and safety. This study aimed to evaluate the quality and reliability of BCAA supplements related to English videos on YouTube^™ and to synthesize with the sentiment-emotion analysis of comments on videos. The content analysis of the information on videos was evaluated with the use of DISCERN, Journal of American Medical Association (JAMA) benchmark criteria, and Global Quality Score (GQS). In addition, word cloud and sentiment and emotional analysis of comments in videos were performed with the R package. As a result, the mean ± standard error values of DISCERN, JAMA, and GQS scores of all videos were 29.27 ± 1.97, 1.95 ± 0.12, and 2.13 ± 0.17, respectively. It was found that advertisement-free videos have a significantly higher DISCERN and GQS score than advertisement-included videos (p < 0.05). A moderately significant positive correlation was determined between DISCERN score of video content and the positive sentiment of video comments (rs: 0.400, p = 0.002). In conclusion, it was determined that BCAA-related YouTube^™ videos have mostly very poor quality in terms of content and that videos with higher quality may receive positive comments from viewers according to the DISCERN instrument.

Branched-chain amino acids promotes the repair of exercise-induced muscle damage via enhancing macrophage polarization

The repair of exercise-induced muscle damage (EIMD) is closely related with inflammation. Branched-chain amino acids (BCAAs), as a nutritional supplement, promote EIMD repair; however, the underlying mechanism remains unclear. In vivo, Sprague-Dawley rats were subjected to Armstrong's eccentric exercise (a 120-min downhill run with a slope of -16° and a speed of 16 m min^-1) to induce EIMD and BCAA supplement was administered by oral gavage. Protein expression of macrophages (CD68 and CD163) and myogenic regulatory factors (MYOD and MYOG) in gastrocnemius was analyzed. Inflammatory cytokines and creatine kinase (CK) levels in serum was also measured. In vitro, peritoneal macrophages from mice were incubated with lipopolysaccharide (LPS) or IL-4 with or without BCAAs in culture medium. For co-culture experiment, C2C12 cells were cultured with the conditioned medium from macrophages prestimulated with LPS or IL-4 in the presence or absence of BCAAs. The current study indicated BCAA supplementation enhanced the M1/M2 polarization of macrophages in skeletal muscle during EIMD repair, and BCAAs promoted M1 polarization through enhancing mTORC1-HIF1α-glycolysis pathway, and promoted M2 polarization independently of mTORC1. In addition, BCAA-promoted M1 macrophages further stimulated the proliferation of muscle satellite cells, whereas BCAA-promoted M2 macrophages stimulated their differentiation. Together, these results show macrophages mediate the BCAAs' beneficial impacts on EIMD repair via stimulating the proliferation and differentiation of muscle satellite cells, shedding light on the critical role of inflammation in EIMD repair and the potential nutritional strategies to ameliorate muscle damage.

Functional Nutrients to Ameliorate Neurogenic Muscle Atrophy

Neurogenic muscle atrophy is a debilitating condition that occurs from nerve trauma in association with diseases or during aging, leading to reduced interaction between motoneurons and skeletal fibers. Current therapeutic approaches aiming at preserving muscle mass in a scenario of decreased nervous input include physical activity and employment of drugs that slow down the progression of the condition yet provide no concrete resolution. Nutritional support appears as a precious tool, adding to the success of personalized medicine, and could thus play a relevant part in mitigating neurogenic muscle atrophy. We herein summarize the molecular pathways triggered by denervation of the skeletal muscle that could be affected by functional nutrients. In this narrative review, we examine and discuss studies pertaining to the use of functional ingredients to counteract neurogenic muscle atrophy, focusing on their preventive or curative means of action within the skeletal muscle. We reviewed experimental models of denervation in rodents and in amyotrophic lateral sclerosis, as well as that caused by aging, considering the knowledge generated with use of animal experimental models and, also, from human studies.

Chronic Intake of a Meal Including Alaska Pollack Protein Increases Skeletal Muscle Mass and Strength in Healthy Older Women: A Double-Blind Randomized Controlled Trial

BACKGROUND

In animal studies, a meal containing Alaska pollack protein (APP) induces fast-twitch muscle hypertrophy. To our knowledge, no interventional studies have examined the benefits of APP intake on muscle mass and muscle weakness and the prevention of sarcopenia in older individuals.

OBJECTIVES

We evaluated the effects of APP intake on skeletal muscle mass, muscle strength, and physical performance among healthy community-dwelling older Japanese women.

METHODS

In this double-blind randomized controlled trial, healthy women ≥ 65 y old were allocated to an APP or whey protein control (CON) group. Participants ingested test protein meals (5.0-5.1 g protein/serving) daily for 24 wk. Between-group differences in the change of skeletal muscle mass index (SMI) as the primary outcome and muscle strength as a secondary outcome were tested using multifrequency BIA and a handheld dynamometer, respectively, at baseline, and 4, 12, and 24 wk. The mean changes in the measured primary and secondary outcome variables from baseline to 4, 12, and 24 wk were compared using unpaired t tests.

RESULTS

There were no between-group differences in nutritional status, food intake, or total energy and protein intakes at baseline, 12 wk, or 24 wk. The change in SMI was 0.12 kg/m2 (95% CI: 0.01, 0.23 kg/m2) and 0.11 kg/m2 (95% CI: 0.03, 0.19 kg/m2) greater in the APP group than in the CON group at 12 wk and 24 wk (P ≤ 0.03) and knee extension strength was 0.07 Nm/kg BW (95% CI: 0.02, 0.12 Nm/kg BW) and 0.05 Nm/kg BW (95% CI: 0.00, 0.09 Nm/kg BW) higher in the APP group than in the CON group at these times (P ≤ 0.015), respectively. The groups did not differ at 4 wk.

CONCLUSIONS

Daily intake of a meal containing APP compared with whey protein increases skeletal muscle mass and lower-extremity muscle strength in healthy older women, suggesting that an APP-containing meal may be useful in the prevention of sarcopenia in this group.This trial was registered at as UMIN000035718.

Metabolic Pathways and Ion Channels Involved in Skeletal Muscle Atrophy: A Starting Point for Potential Therapeutic Strategies

Skeletal muscle tissue has the important function of supporting and defending the organism. It is the largest apparatus in the human body, and its function is important for contraction and movements. In addition, it is involved in the regulation of protein synthesis and degradation. In fact, inhibition of protein synthesis and/or activation of catabolism determines a pathological condition called muscle atrophy. Muscle atrophy is a reduction in muscle mass resulting in a partial or complete loss of function. It has been established that many physiopathological conditions can cause a reduction in muscle mass. Nevertheless, it is not well known that the molecular mechanisms and signaling processes caused this dramatic event. There are multiple concomitant processes involved in muscle atrophy. In fact, the gene transcription of some factors, oxidative stress mechanisms, and the alteration of ion transport through specific ion channels may contribute to muscle function impairment. In this review, we focused on the molecular mechanisms responsible for muscle damage and potential drugs to be used to alleviate this disabling condition.

1H NMR Urinary Metabolomic Analysis in Older Adults after Hip Fracture Surgery May Provide Valuable Information for Patient Profiling-A Preliminary Investigation

In these times of precision and personalized medicine, profiling patients to identify their needs is crucial to providing the best and most cost-effective treatment. In this study, we used urine metabolomics to explore the characterization of older adults with hip fractures and to explore the forecasting of patient outcomes. Overnight urine specimens were collected from 33 patients (mean age 80 ± 8 years) after hip fracture surgery during their stay at a rehabilitation hospital. The specimens were analyzed with ¹H NMR spectroscopy. We performed a metabolomics study regarding assessments of frailty status, Functional Independence Measure (FIM), and Short Physical Performance Battery (SPPB). The main metabolic variations concerned 10 identified metabolites: paracetamol derivatives (4 peaks: 2.15 ppm; 2.16 ppm; 7.13 ppm and 7.15 ppm); hippuric acid; acetate; acetone; dimethylamine; glycine; alanine; lactate; valine; TMAO. At baseline, the urinary levels of these metabolites were significantly higher (i) in frail compared with non-frail patients, (ii) in persons with poorer FIM scores, and (iii) in persons with poorer compared SPPB scores. Our findings suggested that patients with increased levels of urine metabolites associated with metabolic, inflammatory, and renal disorders presented clear signs of frailty, impaired functional independence, and poor physical performance. Metabolomics could be a valuable tool to further characterize older adults, especially after major medical events.

Dietary Branched-Chain Amino Acids (BCAAs) and Risk of Dyslipidemia in a Chinese Population

This study aimed to explore the association between dietary BCAAs, blood lipid levels and risk of dyslipidemia. In this case−control study, a total of 9541 subjects with normal blood lipids were included as a control group, and 9792 patients with dyslipidemia were included as a case group. Dietary BCAA intake data were measured using 3-day 24 h meal recalls and household condiment weighing. All samples were from China Nutrition and Health Surveillance (2015). Generalized linear model, logistic regression, and restricted cubic spline (RCS) were used to evaluate the relationship between dietary BCAAs, blood lipids and dyslipidemia. After adjusting for confounding factors, dietary BCAAs were positively correlated with TC and LDL-C (p < 0.05). Higher dietary BCAAs were associated with higher OR for Hypercholesteremia (Q4 vs. Q1, OR = 1.29, 95% CI: 1.05−1.58, p-trend = 0.034). The ORs of Hyper-LDL-cholesterolemia showed inverted U-shaped with increasing dietary BCAAs (Q3 vs. Q1, OR = 1.20, 95% CI: 1.03−1.39; Q2 vs. Q1, OR = 1.05, 95% CI: 1.01−1.31). The relationship between dietary BCAAs and the risk of Hypercholesteremia and Hyper-LDL-cholesterolemia were both nonlinear (p nonlinearity = 0.0059, 0.0198). Our study reveals that dietary BCAAs are associated with specific types of lipids and risk of dyslipidemia, some of which may be non-linear.

Perspective: Vegan Diets for Older Adults? A Perspective On the Potential Impact On Muscle Mass and Strength

Consumers are increasingly encouraged to consume more plant-based foods and lower their consumption of foods from animal origin. Concurrently, older adults are recommended to consume an adequate amount of high-quality dietary protein for the prevention of age-related muscle loss. In the current Perspective article, we discuss why it may not be preferred to consume a vegan diet at an older age. Our perspective is based on the proposed lower bioavailability and functionality of proteins in a vegan diet due to the matrix of the whole-food protein sources, the lower essential amino acid (EAA) content, and specific EAA deficiencies in proteins derived from plant-based foods. We propose that a vegan diet increases the risk of an inadequate protein intake at an older age and that current strategies to improve the anabolic properties of plant-based foods are not feasible for many older adults. We provide recommendations for further research to substantiate the remaining knowledge gaps regarding the consequences of a vegan diet on skeletal muscle mass and strength at an older age.

From the Bench to the Bedside: Branched Amino Acid and Micronutrient Strategies to Improve Mitochondrial Dysfunction Leading to Sarcopenia

With extended life expectancy, the older population is constantly increasing, and consequently, so too is the prevalence of age-related disorders. Sarcopenia, the pathological age-related loss of muscle mass and function; and malnutrition, the imbalance in nutrient intake and resultant energy production, are both commonly occurring conditions in old adults. Altered nutrition plays a crucial role in the onset of sarcopenia, and both these disorders are associated with detrimental consequences for patients (e.g., frailty, morbidity, and mortality) and society (e.g., healthcare costs). Importantly, sarcopenia and malnutrition also share critical molecular alterations, such as mitochondrial dysfunction, increased oxidative stress, and a chronic state of low grade and sterile inflammation, defined as inflammageing. Given the connection between malnutrition and sarcopenia, nutritional interventions capable of affecting mitochondrial health and correcting inflammageing are emerging as possible strategies to target sarcopenia. Here, we discuss mitochondrial dysfunction, oxidative stress, and inflammageing as key features leading to sarcopenia. Moreover, we examine the effects of some branched amino acids, omega-3 PUFA, and selected micronutrients on these pathways, and their potential role in modulating sarcopenia, warranting further clinical investigation.