Loss of Muscle Mass and Strength After Hip Fracture: an Intervention Target for Nutrition Supplementation

PURPOSEOF REVIEW

To summarize what is known about the deleterious effect of hip fracture on muscle mass and strength as well as the scientific evidence for post-surgical nutrition supplementation to maintain muscle and improve function.

RECENT FINDINGS

This review provides a discussion of the relationship between muscle mass, strength, and physical function following hip fracture, briefly describes the approaches to measuring lean mass, discusses prevalence of sarcopenia and malnutrition among older men and women with hip fracture, and reviews the effects of essential amino acids on muscle. Loss of muscle mass and strength following hip fracture is substantial with consequences for recovery of functional independence. EAA-based nutrition supplementation, which directly effects muscle, has potential to improve outcomes.

Low Muscle Mass Is Associated with Poorer Glycemic Control and Higher Oxidative Stress in Older Patients with Type 2 Diabetes

Body composition changes that occur during aging, such as loss of lean mass, are unfavorable at metabolic level and they can explain, in part, the appearance of certain age-associated diseases such as type 2 diabetes (T2D). Separately, T2D is associated with an increase in oxidative stress (OS) which negatively affects skeletal muscle. Our aim was to study the differences in clinical and nutritional parameters, disease control, and OS in a cohort of older patients with T2D classified according to the amount of lean mass they had. We included 100 adults older than 65 years with T2D. We found that women with low fat-free mass and muscle mass have worse T2D metabolic control. Moreover, the patients with a low percentile of muscle mass present a high value of OS. The study shows that the presence of low lean mass (LM) in the geriatric population diagnosed with T2D is associated with poorer glycemic control and greater OS.

Leucine Intake and Risk of Impaired Physical Function and Frailty in Older Adults

BACKGROUND

Leucine is suggested to play a central role in age-related physical decline, but the effect of dietary leucine intake on physical functioning is uncertain. We examined the prospective association between dietary leucine intake and impaired lower-extremity function (ILEF) and frailty in older adults.

METHODS

We used data from 2 956 adults aged ≥60 and older from the Seniors-ENRICA cohort. At baseline (2008-2010) and in 2012, dietary information was obtained with a validated computerized face-to-face diet history, from which energy-adjusted cumulative leucine intake per body weight was calculated. Participants were followed up through 2017 to assess incident ILEF, ascertained with the Short Physical Performance Battery, and incident frailty, according to the Fried phenotype criteria. Statistical analysis was performed with Cox models adjusted for the main potential confounders.

RESULTS

During follow-up, we identified 515 incident cases of ILEF and 241 of frailty. Compared with participants in the lowest tertile of leucine intake (35.5-89.0 mg/kg/d), those in the highest tertile (107.4-372.5 mg/kg/d) had a lower risk of ILEF (fully adjusted hazard ratio [95% confidence interval]: 0.70 [0.53-0.93], p trend: .01) and of frailty (0.63 [0.41-0.96], p trend: .03]. A higher consumption of important sources of leucine in this population, including unprocessed beef, oily and white fish, and bread, were also associated with a lower risk of incident ILEF and frailty.

CONCLUSIONS

Higher leucine intake was associated with reduced risk of ILEF and frailty. Dietary leucine, obtained from foods rich in high-quality protein, could be a key nutrient to prevent age-related physical function decline in older adults.

(Mal)nutrition in critical illness and beyond: a narrative review

Close liaison with ICU-trained dietitians and early initiation of nutrition is a fundamental principle of care of critically ill patients- this should be done while monitoring closely for refeeding syndrome. Enteral nutrition delivered by volumetric pumps should be used where possible, though parenteral nutrition should be started early in patients with high nutritional risk factors. Malnutrition and loss of muscle mass are common in patients who are admitted to ICUs and are prognostic for patient-centred outcomes including complications and mortality. Obesity is part of that story, and isocaloric and high-protein provision of nutrition is important in this group of patients who comprise a growing proportion of people treated. Assessing protein stores and appropriate dosing is, however, challenging in all groups of patients. It would be beneficial to develop strategies to reduce muscle wasting as well; various strategies including amino acid supplementation, ketogenic nutrition and exercise have been trialled, but the quality of data has been inadequate to address this phenomenon. Nutritional targets are rarely achieved in practice, and all ICUs should incorporate clear guidelines to help address this. These should include local nutritional and fasting guidelines and for the management of feed intolerance, early access to post-pyloric feeding and a multidisciplinary framework to support the importance of nutritional education.

Dietary Modifications in Critically-Ill Patients: A Comparison of Persian Medicine and Conventional Medicine Perspectives

In Persian Medicine (PM) literature, a crisis is the culmination of the body's response to illness, which necessitates fundamental dietary modification to improve prognosis. In this narrative review, authentic PM textbooks as well as articles on diets for critically-ill patients (CIPs) obtained from PubMed and Google Scholar databases, were reviewed, and after gathering data, they were classified, coded, analyzed, and compared. In the acute phase, both PM and conventional medicine agree on relative food restriction, but PM lays a special focus on the use of meat in cases of weakness. There are both similarities and differences between PM and conventional medicine regarding nutritional recommendations in critical illness. For example, recommendations for food restriction and protein intake are similar in both schools, but recommendations for carbohydrate intake are different. The variables addressed and emphasized in PM require further evaluation in clinical trials.

HMB and leucine supplementation during critical illness and recovery

PURPOSE OF REVIEW

Skeletal muscle wasting is a serious consequence of critical illness, which may impact on long term physical and functional disability. To date, no intervention has been proven to reduce skeletal muscle wasting. Leucine and it's metabolite β-hydroxy-β-methylbutyrate (HMB) have been proposed as interventions. This review details the mechanism of action of both leucine and HMB, discusses the most recent research for both leucine and HMB and lastly discusses considerations for future research.

RECENT FINDINGS

Only one study of leucine in critical illness has recently been published. This was a feasibility study where the physiological and muscle related outcomes were not reported to be feasible. Three studies on HMB have been reported recently with no effect seen on either muscle mass or strength. The main limitation in our understanding of the potential use of leucine or HMB on skeletal muscle wasting is the lack of mechanistic studies available in this population.

SUMMARY

Mechanistic studies should be a priority before embarking on further randomized controlled trials related to this topic.

Is the amino acid pattern in medical nutrition therapy crucial for successfully attenuating muscle mass loss in adult ICU patients? Secondary analysis of a RCT

BACKGROUND AND AIMS

We hypothesized that in long-term immobilized intensive care unit (ICU) patients, both the quantity and quality of protein nutrition are vital in supporting muscle mass maintenance. Hence, the aim of this secondary analysis of our recently performed RCT was to calculate the intake of individual amino acids and to evaluate the potential associations of amino acid patterns with muscle mass loss during the ICU stay.

METHODS

Clinical and nutritional data were collected from a recent RCT conducted in long-term immobilized, critically ill patients receiving medical nutrition therapy with either 1.8 g (interventional group) or 1.2 g (standard group) of protein/amino acids per kg body weight per day over 4 weeks. Intake of the individual amino acids as well as the sum scores of the indispensable, conditionally indispensable, and dispensable amino acids were calculated for all patients, both group specific (n = 21 in each group) and in total (n = 42), based on the detailed nutrition protocols; inter-group differences were analyzed by t-tests. Linear regression models were used to test the effects of individual amino acids and the sum scores on the extent of skeletal muscle loss by measuring the quadriceps muscle layer thickness during the study period. The significance level was adjusted for multiple testing according to the Bonferroni procedure (α = 0.002).

RESULTS

In both groups, the proportion of indispensable amino acids was approximately 41% of the total exogenous protein supply, with the proportion of enteral administration slightly over 50%. The intake of conditionally indispensable amino acids (glutamine, tyrosine, cysteine, histidine, and arginine) accounted for 17% and 18% of the total amino acids in the interventional and standard groups, respectively; glutamine (5% of total amino acids) was exclusively administered enterally. The intake of dispensable amino acid varied widely, with glutamic acid, proline, and asparagine/aspartic acid representing the highest proportions (10%, 8%, and 8% of total amino acids, respectively). For all amino acids, no statistically significant association was observed between the quantitative intake and the skeletal muscle changes after terminating the intervention phase.

CONCLUSION

This secondary analysis of the RCT conducted in routine clinical practice did not support our working hypothesis that the amino acid patterns of medical nutrition therapy have a statistically significant impact on the skeletal muscle loss in long-term immobilized ICU patients. Due to the limited variety of enteral/parenteral products used in this single-center study, the calculated amino acid patterns showed only small differences. Larger multi-center trials with adequate power are needed to evaluate the potential effects of the individual amino acids or defined amino acid patterns on the muscle protein metabolism in further detail.

TRIAL REGISTRATION

German Clinical Trials Register (http://www.drks.de); DRKS-ID: DRKS00013594.

Effects of enteral nutrition on heart function, inflammatory markers and immune function in elderly patients with chronic heart failure

Objectives:

To evaluate the effect of enteral nutrition on heart function, inflammatory markers and immune function in elderly patients with chronic heart failure and its clinical significance.

Methods:

Eighty patients with moderate and severe heart failure admitted to the Cardiology Intensive Care Unit (CCU) of Baoding First Central Hospital from May 2019 to May 2020 were included in this study and randomly divided into two groups: the experimental group and the control group, with 40 patients in each group. The experimental group was given enteral nutrition support therapy on the basis of conventional therapy for one month, while the control group was given restricted salt and water intake on the basis of conventional therapy, and patients were given free diet according to their wishes. The changes in heart function before and after treatment, changes in inflammatory factors such as TNF-a, CRP, IL-6, changes in levels of immunoglobulins such as IgA, IgM, and IgG, and the improvement of the performance status of the two groups were compared and analyzed.

Results:

After treatment, indicators such as BNP, LVEDD, LVEF and 6min walking distance in the experimental group were significantly improved compared with the control group, with statistically significant differences (p<0.05), and the levels of inflammatory factors such as TNF-a, CRP and IL-6 in the experimental group were significantly reduced compared with those in the control group (p=0.00). The levels of IgG, IgA, IgM and other immunoglobulins in the experimental group improved more significantly after treatment than those in the control group, with statistically significant differences (IgG, IgA, p=0.00; IgM, p=0.01). Moreover, the experimental group was significantly superior to the control group in the improvement rate of performance status score (ECOG) after treatment (p=0.04); The incidence of gastrointestinal adverse reactions in the experimental group was 20%, and that in the control group was 15%. No statistically significant difference can be observed in the gastrointestinal tolerance of both groups (p=0.56).

Conclusions:

Reasonable enteral nutrition boasts a variety of benefits for the recovery of elderly patients with chronic heart failure. With reasonable enteral nutrition, the heart function of elderly patients with chronic heart failure can be significantly improved, inflammatory factors can be reduced, immunity and performance status can be enhanced, and gastrointestinal tolerance can be ameliorated without obvious gastrointestinal reactions.

Screening, Diagnosis and Management of Sarcopenia and Frailty in Hospitalized Older Adults: Recommendations from the Australian and New Zealand Society for Sarcopenia and Frailty Research (ANZSSFR) Expert Working Group

Sarcopenia and frailty are highly prevalent conditions in older hospitalized patients, which are associated with a myriad of adverse clinical outcomes. This paper, prepared by a multidisciplinary expert working group from the Australian and New Zealand Society for Sarcopenia and Frailty Research (ANZSSFR), provides an up-to-date overview of current evidence and recommendations based on a narrative review of the literature for the screening, diagnosis, and management of sarcopenia and frailty in older patients within the hospital setting. It also includes suggestions on potential pathways to implement change to encourage widespread adoption of these evidence-informed recommendations within hospital settings. The expert working group concluded there was insufficient evidence to support any specific screening tool for sarcopenia and recommends an assessment of probable sarcopenia/sarcopenia using established criteria for all older (≥65 years) hospitalized patients or in younger patients with conditions (e.g., comorbidities) that may increase their risk of sarcopenia. Diagnosis of probable sarcopenia should be based on an assessment of low muscle strength (grip strength or five times sit-to-stand) with sarcopenia diagnosis including low muscle mass quantified from dual energy X-ray absorptiometry, bioelectrical impedance analysis or in the absence of diagnostic devices, calf circumference as a proxy measure. Severe sarcopenia is represented by the addition of impaired physical performance (slow gait speed). All patients with probable sarcopenia or sarcopenia should be investigated for causes (e.g., chronic/acute disease or malnutrition), and treated accordingly. For frailty, it is recommended that all hospitalized patients aged 70 years and older be screened using a validated tool [Clinical Frailty Scale (CFS), Hospital Frailty Risk Score, the FRAIL scale or the Frailty Index]. Patients screened as positive for frailty should undergo further clinical assessment using the Frailty Phenotype, Frailty Index or information collected from a Comprehensive Geriatric Assessment (CGA). All patients identified as frail should receive follow up by a health practitioner(s) for an individualized care plan. To treat older hospitalized patients with probable sarcopenia, sarcopenia, or frailty, it is recommended that a structured and supervised multi-component exercise program incorporating elements of resistance (muscle strengthening), challenging balance, and functional mobility training be prescribed as early as possible combined with nutritional support to optimize energy and protein intake and correct any deficiencies. There is insufficient evidence to recommend pharmacological agents for the treatment of sarcopenia or frailty. Finally, to facilitate integration of these recommendations into hospital settings organization-wide approaches are needed, with the Spread and Sustain framework recommended to facilitate organizational culture change, with the help of 'champions' to drive these changes. A multidisciplinary team approach incorporating awareness and education initiatives for healthcare professionals is recommended to ensure that screening, diagnosis and management approaches for sarcopenia and frailty are embedded and sustained within hospital settings. Finally, patients and caregivers' education should be integrated into the care pathway to facilitate adherence to prescribed management approaches for sarcopenia and frailty.

Tolerable amounts of amino acids for human supplementation: summary and lessons from published peer-reviewed studies

Amino acid supplementation may be indicated to correct for insufficient amino acid intake in healthy individuals, and in specific physiological or pathophysiological situations. However, there is a concern to not supplement beyond the tolerable upper intake level (UL) by determining parameters of no-observed-adverse-effect level (NOAEL) or lowest-observed-adverse-effect level (LOAEL) for each amino acid. Since the NOAEL and LOAEL values are at least one order of magnitude different when comparing the values obtained in rats and humans, the aim of this review is to evaluate to what extent the amino acid UL measured in the rat model, when referenced to the dietary usual consumption (UC) and dietary requirement (RQ) for indispensable amino acids, may be used as an approximation of the UL in humans. This review then compares the ratios of the NOAEL or LOAEL over UC and RQ in the rat model with the same ratios calculated in humans for the nine amino acids (arginine, serine, glycine, histidine, leucine, lysine, methionine, phenylalanine, and tryptophan) for which this comparison can be done. From the calculations made, it appears that for these 9 amino acids, the calculated ratios for rats and humans, although rather different for several amino acids, remains for all of them in the same order of magnitude. For tryptophan, tyrosine, and valine, the ratios calculated in rats are markedly different according to the sex of animals, raising the view that it may be also the case in humans.

How to Increase Muscle Mass in Critically Ill Patients: Lessons Learned from Athletes and Bodybuilders

PURPOSE OF REVIEW

Decades of research on nutrition and exercise on athletes and bodybuilders has yielded various strategies to promote anabolism and improve muscle health and growth. We reviewed these interventions in the context of muscle loss in critically ill patients.

RECENT FINDINGS

For critically ill patients, ensuring optimum protein intake is important, potentially using a whey-containing source and supplemented with vitamin D and leucine. Agents like hydroxyl β-methylbutyrate and creatine can be used to promote muscle synthesis. Polyunsaturated fatty acids stimulate muscle production as well as have anti-inflammatory properties that may be useful in critical illness. Adjuncts like oxandralone promote anabolism. Resistance training has shown mixed results in the ICU setting but needs to be explored further with specific outcomes. Critically ill patients suffer from severe proteolysis during hospitalization as well as persistent inflammation, immunosuppression, and catabolism syndrome after discharge. High protein supplementation, ergogenic aids, anti-inflammatories, and anabolic adjuncts have shown potential in alleviating muscle loss and should be used in intensive care units to optimize patient recovery.

Specialized nutrition improves muscle function and physical activity without affecting chemotherapy efficacy in C26 tumour-bearing mice

BACKGROUND

Skeletal muscle wasting and fatigue are commonly observed in cancer patients receiving chemotherapy and associated with reduced treatment outcome and quality of life. Nutritional support may mitigate these side effects, but potential interference with chemotherapy efficacy could be of concern. Here, we investigated the effects of an ω-3 polyunsaturated fatty acid (eicosapentaenoic acid and docosahexaenoic acid), leucine-enriched, high-protein (100% whey), additional vitamin D, and prebiotic fibres 'specific nutritional composition' (SNC) and chemotherapy on state-of-the-art tumour organoids and muscle cells and studied muscle function, physical activity, systemic inflammation, and chemotherapy efficacy in a mouse model of aggressive colorectal cancer (CRC).

METHODS

Tumour-bearing mice received a diet with or without SNC. Chemotherapy treatment consisted of oxaliplatin and 5-fluorouracil. Tumour formation was monitored by calliper measurements. Physical activity was continuously monitored by infrared imaging. Ex vivo muscle performance was determined by myography, muscle fatty acid composition by gas chromatography, and plasma cytokine levels by Luminex xMAP technology. Patient-derived CRC organoids and C2C12 myotubes were used to determine whether SNC affects chemotherapy sensitivity in vitro.

RESULTS

Specific nutritional composition increased muscle contraction capacity of chemotherapy-treated tumour-bearing mice (P < 0.05) and enriched ω-3 fatty acid composition in muscle without affecting treatment efficacy (P < 0.0001). Mice receiving SNC maintained physical activity after chemotherapy and showed decreased systemic inflammation. Therapeutic response of CRC organoids was unaffected by SNC nutrients, while cell viability and protein synthesis of muscle cells significantly improved.

CONCLUSIONS

The results show that specialized nutritional support can be used to maintain muscle function and physical activity levels during chemotherapy without increasing tumour viability. Therefore, nutritional strategies have potential value in promoting cancer and chemotherapy tolerance.

Nutritional interventions to improve muscle mass, muscle strength, and physical performance in older people: an umbrella review of systematic reviews and meta-analyses

CONTEXT

Sarcopenia is a progressive and generalized skeletal muscle disorder associated with an increased risk of adverse outcomes such as falls, disability, and death. The Belgian Society of Gerontology and Geriatrics has developed evidence-based guidelines for the prevention and treatment of sarcopenia. This umbrella review presents the results of the Working Group on Nutritional Interventions.

OBJECTIVE

The aim of this umbrella review was to provide an evidence-based overview of nutritional interventions targeting sarcopenia or at least 1 of the 3 sarcopenia criteria (ie, muscle mass, muscle strength, or physical performance) in persons aged ≥ 65 years.

DATA SOURCES

Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, the PubMed and Web of Science databases were searched for systematic reviews and meta-analyses reporting the effect of nutritional supplementation on sarcopenia or muscle mass, strength, or physical performance.

DATA EXTRACTION

Two authors extracted data on the key characteristics of the reviews, including participants, treatment, and outcomes. Methodological quality of the reviews was assessed using the product A Measurement Tool to Assess Systematic Reviews. Three authors synthesized the extracted data and generated recommendations on the basis of an overall synthesis of the effects of each intervention. Quality of evidence was rated with the Grading of Recommendations Assessment, Development and Evaluation approach.

DATA ANALYSIS

A total of 15 systematic reviews were included. The following supplements were examined: proteins, essential amino acids, leucine, β-hydroxy-β-methylbutyrate, creatine, and multinutrient supplementation (with or without physical exercise). Because of both the low amount and the low to moderate quality of the reviews, the level of evidence supporting most recommendations was low to moderate.

CONCLUSIONS

Best evidence is available to recommend leucine, because it has a significant effect on muscle mass in elderly people with sarcopenia. Protein supplementation on top of resistance training is recommended to increase muscle mass and strength, in particular for obese persons and for ≥ 24 weeks. Effects on sarcopenia as a construct were not reported in the included reviews.

Effects of Nutritional Interventions on Nutritional and Functional Outcomes in Geriatric Rehabilitation Patients: A Systematic Review and Meta-Analysis

OBJECTIVES

It has been recognized that nutritional interventions play a role in improving the nutritional and functional status of older persons. This systematic review summarizes the evidence on nutritional and functional outcomes of nutritional interventions alone or in combination with physical exercise in geriatric rehabilitation patients.

DESIGN

Eight electronic databases were searched until July 1, 2019 to identify nutritional intervention studies in patients aged ≥60 years who were admitted to geriatric rehabilitation. A meta-analysis was performed to quantify intervention effects on serum albumin, muscle mass, and hand grip strength (HGS).

RESULTS

A total of 1962 studies were screened and 13 included in the systematic review. Studies were heterogeneous in interventions (4 nutritional interventions, 6 physical exercise + nutritional intervention, 1 timing of protein provision, 1 exercise + dietary advice, 1 nutrition-related nursing care) and outcomes. Among the 9 interventions that tested oral nutritional supplements (ONS) with protein, with or without exercise, 7 studies reported protein intake and 6 showed increased protein intakes, 2 of 5 studies showed increased albumin levels, and 5 of 9 reported an improvement in functional outcomes (BI, Functional Independence Measure, mobility). Meta-analyses showed no significant intervention effects on albumin [standardized mean difference (SMD) 0.45, 95% confidence interval (CI) -0.14, 1.04 (4 studies)], muscle mass [mean difference (MD) 2.14 kg, 95% CI -2.17, 6.45 (3 studies)], and HGS [SMD -0.04, 95% CI -0.55, 0.63 (3 studies)], but was based on a very limited number of studies.

CONCLUSIONS AND IMPLICATIONS

Only a limited number of studies with heterogeneous nutritional interventions and outcomes were available in the geriatric rehabilitation population. Studies that included ONS improved nutritional outcomes, especially protein intake and albumin levels. Functional outcomes improved in the majority of reporting studies. This indicates benefits of protein supplementation, with or without exercise, in this population. Future well-designed and well-powered clinical trials are needed to clarify existing controversial aspects.

Protein Nutritional Support: The Classical and Potential New Mechanisms in the Prevention and Therapy of Sarcopenia

Sarcopenia commonly occurs in the elderly and patients with wasting diseases. The main reason is an imbalance in protein metabolism (protein degradation exceeding protein synthesis). It causes a serious decline in muscle strength and motion ability, even leading to long-term bed rest. Recent studies indicate that nutritional support is beneficial for ameliorating sarcopenia and restoring muscle function. This review will summarize the classical mechanisms of protein nutritional support for alleviating sarcopenia, such as modulating the ubiquitin-proteasome system, oxidative response, and cell autophagy, as well as the potential new mechanisms, including altering miRNA profiles and gut microbiota. In addition, the clinical application and outcome of protein nutritional support in the elderly and patients with wasting diseases are also introduced. Protein nutritional support is expected to provide new approaches for the prevention and adjuvant therapy of sarcopenia.

Protective Effects of Ghrelin on Fasting-Induced Muscle Atrophy in Aging Mice

Sarcopenia is the aging-associated progressive loss of skeletal muscle; however, the pathogenic mechanism of sarcopenia is not clear. The orexigenic hormone ghrelin stimulates growth hormone secretion, increases food intake, and promotes adiposity. Here we showed that fasting-induced muscle loss was exacerbated in old ghrelin-null (Ghrl-/-) mice, exhibiting decreased expression of myogenic regulator MyoD and increased expression of protein degradation marker MuRF1, as well as altered mitochondrial function. Moreover, acylated ghrelin and unacylated ghrelin treatments significantly increased mitochondrial respiration capacity in muscle C2C12 cells. Consistently, acylated ghrelin and unacylated ghrelin treatments effectively increased myogenic genes and decreased degradation genes in the muscle in fasted old Ghrl-/- mice, possibly by stimulating insulin and adenosine monophosphate-activated protein kinase pathways. Furthermore, Ghrl-/- mice showed a profile of pro-inflammatory gut microbiota, exhibiting reduced butyrate-producing bacteria Roseburia and ClostridiumXIVb. Collectively, our results showed that ghrelin has a major role in the maintenance of aging muscle via both muscle-intrinsic and -extrinsic mechanisms. Acylated ghrelin and unacylated ghrelin enhanced muscle anabolism and exerted protective effects for muscle atrophy. Because unacylated ghrelin is devoid of the obesogenic side effect seen with acylated ghrelin, it represents an attractive therapeutic option for sarcopenia.

[Muscle in critically ill patients]

Introduction

Polyneuropathy in the critically ill patient was defined as a generalized weakness, acquired during Intensive Care Unit (ICU) admittance and attributed to lesion of the peripheral nerve. Research in this field progressed over time, revealing the crucial role of muscle injury in this disease, to the point of re-naming the disorder as ICU adquired weakness (ICUAW). Muscle damage is common in severe illness, and may be classified in qualitative (weakness) or quantitative (decrease in mass) muscle loss. The most frequent scenario in these patients, is simultaneous change in quality and quantity of muscle; resulting in a challenging and delayed recovery during hospital admittance and after discharge. Multiple causes have been identified in the pathogenesis of this disorder, such as: prolonged bed rest, inadequate intake of nutrients and exposure to drugs that affect muscle structure and contraction. The assessment of muscle mass using images provided by ultrasound or computerized tomography may guide follow up. The prevention and treatment of ICUAW requires a multimodal approach: early mobilization and exercise, appropriate nutritional prescription and, occasionally, muscle protein synthesis stimulants. Further studies will clarify more aspects regarding critically ill patients suffering from muscle injury, in order to better address prevention and treatment of ICUAW.

Systematic Review With Meta-Analysis of Patient-Centered Outcomes, Comparing International Guideline-Recommended Enteral Protein Delivery With Usual Care

BACKGROUND

International guidelines recommend that protein be administered enterally to critically ill patients at doses between 1.2 and 2 g/kg per day Observational data indicate that patients frequently receive less protein. The aim of this systematic review was to evaluate patient-centered outcomes with guideline-recommended enteral protein compared with usual care.

METHODS

A systematic review was performed of randomized controlled trials including critically ill adult patients provided predominately enteral nutrition with mean protein at ≥1.2 g/kg per day (intervention) and <1.2 g/kg per day (comparator). Random-effects models were applied for outcomes reported in ≥3 trials.

RESULTS

Of 1375 abstracts, 69 full-text articles were reviewed, and 6 trials meet the inclusion criteria, including 511 patients. The intervention group received a mean (SD) of 1.3 (0.08) g/kg per day, and the comparator group received 0.75 (0.15) g/kg per day protein. Insufficient data were available for meta-analyses on the primary outcome (muscle mass or strength). According to our meta-analyses, mortality at 28 days (5 studies) (risk ratio 0.92 [95% Cl 0.63-1.35], P = .66) and the durations of intensive care unit (6 studies) and hospital admission (4 studies) were similar between the intervention and comparator, with some uncertainty due to sample sizes and heterogeneity.

CONCLUSION

There are insufficient data to conclude whether protein provision within the current international guideline recommendations improves outcomes. In a limited dataset, enteral protein intakes near the lower level of current recommendations do not appear to reduce admission duration or mortality when compared with usual care in critically ill.

Advantage of Dairy for Improving Aging Muscle

The risk of sarcopenia increases with aging. Malnutrition in the elderly population is an important risk factor for sarcopenia. Calcium (Ca), phosphate (P), vitamin D and protein are key nutrients for the human body and affect muscle mass and quality. Dairy products are rich in these nutrients, which implicates that dairy products might be ideal for elderly population. This systematic review highlights the effects of dairy products on muscle mass, muscle strength and body performance in the elderly population in the perspective of Ca, P, vitamin D and protein.

Leucine-enriched essential amino acid supplementation in mechanically ventilated trauma patients: a feasibility study

Background

Critically ill patients lose up to 2% of muscle mass per day. We assessed the feasibility of administering a leucine-enriched essential amino acid (L-EAA) supplement to mechanically ventilated trauma patients with the aim of assessing the effect on skeletal muscle mass and function.

Methods

A randomised feasibility study was performed over six months in intensive care (ICU). Patients received 5 g L-EAA five times per day in addition to standard feed (L-EAA group) or standard feed only (control group) for up to 14 days. C-reactive protein, albumin, IL-6, IL-10, urinary 3-MH, nitrogen balance, protein turnover ([1-13C] leucine infusion), muscle depth change (ultrasound), functional change (Katz and Barthel indices) and muscle strength Medical Research Council (MRC) sum score to assess ICU Acquired Weakness were measured sequentially.

Results

Eight patients (9.5% of screened patients) were recruited over six months. L-EAA doses were provided on 91/124 (73%) occasions. Inflammatory and urinary marker data were collected; serial muscle depth measurements were lacking due to short length of stay. Protein turnover studies were performed on five occasions. MRC sum score could not be performed as patients were not able to respond to the screening questions. The Katz and Barthel indices did not change. L-EAA delivery was achievable, but meaningful functional and muscle mass outcome measures require careful consideration in the design of a future randomised controlled trial.

Conclusion

L-EAA was practical to provide, but we found significant barriers to recruitment and measurement of the chosen outcomes which would need to be addressed in the design of a future, large randomised controlled trial.

Trial registration

ISRCTN Registry, ISRCTN79066838. Registered on 25 July 2012.

Electronic supplementary material

The online version of this article (10.1186/s13063-019-3639-2) contains supplementary material, which is available to authorized users.

[Functional recovery of the cardio-respiratory patient]

Introduction

Heart failure (HF), chronic obstructive pulmonary disease (COPD), and most chronic diseases are associated with mild to moderate chronic or recurrent inflammation. This inflammation contributes to malnutrition through different mechanisms: anorexia, decreased intake, alteration of metabolism with increased energy expenditure at rest and increased muscle catabolism. The decrease in lean mass has been included as a phenotypic criterion in the recently coined definition of malnutrition. In addition, a greater importance is given to the evaluation of the function, together with that of the morphological parameters. The grip strength, measured with a manual dynamometer and compared to reference populations, is a simple measure of muscle strength and correlates with the strength of the legs. On the other hand, the so-called "paradox of obesity" occurs in both patients with HF and COPD, since overweight and obese patients have lower overall mortality than patients with normal or low body mass index (BMI). The nutritional treatment, with an adequate contribution of macro and micronutrients and a contribution of proteins of fast absorption, with a higher content of leucine or its metabolite β-hydroxy-β-methylbutyrate, seems to offer a benefit in the preservation of muscle mass and its functionality in the patient with cardiorespiratory pathology. Nutritional treatment, associated with a pulmonary or cardiac rehabilitation regimen, is essential to obtain good morphological and functional results.

Muscle weakness: Understanding the principles of myopathy and neuropathy in the critically ill patient and the management options

Myo-neuropathy of the critically ill patient is a difficult nosological entity to understand and manage. It appears soon after injury, and it is estimated that 20-30% of patients admitted to Intensive Care Units will develop it in some degree. Although muscular and nervous involvement are related, the former has a better prognosis. Myo-neuropathy associates to more morbidity, longer stay in Intensive Care Unit and in hospital, and also to higher costs and mortality. It is considered part of the main determinants of the new entities: the Chronic Critical Patient and the Post Intensive Care Syndrome. This update focuses on aetiology, pathophysiology, diagnosis and strategies that can prevent, alleviate and/or improve muscle (or muscle-nerve) weakness.

Impact of heart failure on functional recovery after hip fracture

[Purpose] Heart failure has been identified as a risk factor for reduced physical function and falls; however, the impact of heart failure on functional recovery after a hip fracture is unclear. This study aimed to examine how heart failure and pre-fracture physical function affect recovery after a hip fracture. [Participants and Methods] The study population consisted of 122 patients with sub-acute hip fracture (mean age 81.7 ± 9.7 years, 18.9% male) who were divided into two groups: heart failure and non-heart failure. The outcome measurement was the functional independence measure effectiveness. A two-way analysis of variance was performed to investigate how heart failure and ambulatory ability prior to hip fracture were related to the functional independence measure effectiveness. [Results] Seventeen patients (13.9%) had a history of heart failure. The two-way analysis of variance showed the two independent variables (heart failure and ambulatory ability before fracture) had significant main effects; however, their interaction effect was not significant. [Conclusion] Heart failure affects functional recovery after hip fracture independent of the pre-fracture physical function, and vice versa. Further research on rehabilitation in hip fracture patients with heart failure is required to develop strategies to overcome poor functional recovery in such patients.

Sarcopenic obesity in the ICU

PURPOSE OF REVIEW

Sarcopenic obese in older ICU patients may have a higher risk of poor recovery during and after ICU stay, which may lead to longer hospital stay and poor quality of life. In this review, causes, consequences, and nutrition strategies to combat sarcopenic obesity in the ICU are discussed.

RECENT FINDINGS

Physical inactivity, inflammation, anabolic resistance, as well as disturbances in hormone levels are, important causes for the strongly accelerated decline in muscle mass and muscle strength in ICU patients. These causes may lead to changes in amino acid metabolism and anabolic resistance. Obese individuals show specific muscle characteristics (e.g. adipose infiltration, lower capillary density) which are associated with impaired functionality. Specific energy and protein intake recommendations are needed to attenuate sarcopenic obesity in ICU patients.

SUMMARY

Nutrient utilization in sarcopenic obese ICU patients is a complex challenge as many metabolic factors and clinical situations may impact the efficacy of nutritional interventions. Nutritional strategies should consist of high-protein and hypocaloric feeding along with nonprotein sources such as vitamin D, omega-3 fatty acids, or physical activity. There is a great need, however, for randomized controlled trials (RCTs) combining various nutritional strategies with physical activity in sarcopenic obese ICU patients.

Targeted full energy and protein delivery in critically ill patients: a study protocol for a pilot randomised control trial (FEED Trial)

BACKGROUND

Current guidelines for the provision of protein for critically ill patients are based on incomplete evidence, due to limited data from randomised controlled trials. The present pilot randomised controlled trial is part of a program of work to expand knowledge about the clinical effects of protein delivery to critically ill patients. The primary aim of this pilot study is to determine whether an enteral feeding protocol using a volume target, with additional protein supplementation, delivers a greater amount of protein and energy to mechanically ventilated critically ill patients than a standard nutrition protocol. The secondary aims are to evaluate the potential effects of this feeding strategy on muscle mass and other patient-centred outcomes.

METHODS

This prospective, single-centred, pilot, randomised control trial will include 60 participants who are mechanically ventilated and can be enterally fed. Following informed consent, the participants receiving enteral nutrition in the intensive care unit (ICU) will be allocated using a randomisation algorithm in a 1:1 ratio to the intervention (high-protein daily volume-based feeding protocol, providing 25 kcal/kg and 1.5 g/kg protein) or standard care (hourly rate-based feeding protocol providing 25 kcal/kg and 1 g/kg protein). The co-primary outcomes are the average daily protein and energy delivered to the end of day 15 following randomisation. The secondary outcomes include change in quadriceps muscle layer thickness (QMLT) from baseline (prior to randomisation) to ICU discharge and other nutritional and patient-centred outcomes.

DISCUSSION

This trial aims to examine whether a volume-based feeding protocol with supplemental protein increases protein and energy delivery. The potential effect of such increases on muscle mass loss will be explored. These outcomes will assist in formulating larger randomised control trials to assess mortality and morbidity.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry (ANZCTR), ACTRN: 12615000876594 UTN: U1111-1172-8563.

Role of Oral Nutritional Supplements Enriched with β-Hydroxy-β-Methylbutyrate in Maintaining Muscle Function and Improving Clinical Outcomes in Various Clinical Settings

Aging and disease-related malnutrition are well associated with loss of muscle mass and function. Muscle mass loss may lead to increased health complications and associated increase in health care costs, especially in hospitalized individuals. High protein oral nutritional supplements enriched with β-hydroxy-β-methylbutyrate (HP-ONS+HMB) have been suggested to provide benefits such as improving body composition, maintaining muscle mass and function and even decreasing mortality rates. The present review aimed to examine current evidence on the effect of HP-ONS+HMB on muscle-related clinical outcomes both in community and peri-hospitalization patients. Overall, current evidence suggests that therapeutic nutrition such as HP-ONS+HMB seems to be a promising tool to mitigate the decline in muscle mass and preserve muscle function, especially during hospital rehabilitation and recovery.

Nutrient modulation in the management of disease-induced muscle wasting: evidence from human studies

PURPOSE OF REVIEW

In addition to being essential for movement, skeletal muscles act as both a store and source of key macronutrients. As such, muscle is an important tissue for whole body homeostasis, undergoing muscle wasting in times of starvation, disease, and stress, for example, to provide energy substrates for other tissues. Yet, muscle wasting is also associated with disability, comorbidities, and mortality. As nutrition is so crucial to maintaining muscle homeostasis 'in health', it has been postulated that muscle wasting in cachexia syndromes may be alleviated by nutritional interventions. This review will highlight recent work in this area in relation to muscle kinetics, the acute metabolic (e.g. dietary protein), and longer-term effects of dietary interventions.

RECENT FINDINGS

Whole body and skeletal muscle protein synthesis invariably exhibit deranged kinetics (favouring catabolism) in wasting states; further, many of these conditions harbour blunted anabolic responses to protein nutrition compared with healthy controls. These derangements underlie muscle wasting. Recent trials of essential amino acid and protein-based nutrition have shown some potential for therapeutic benefit.

SUMMARY

Nutritional modulation, particularly of dietary amino acids, may have benefits to prevent or attenuate disease-induced muscle wasting. Nonetheless, there remains a lack of recent studies exploring these key concepts to make conclusive recommendations.

[Common therapeutic approaches of sarcopenia in the elderly and uremic myopathy]

The gradual loss of weight and function of muscle in patients with chronic kidney disease as in the elderly impacts the quality of life. Early management should help slow the functional limitation. Physical activity is the first therapy to propose that ensures stability of muscle mass and improved function. Resistance training programs have proven effective but are not yet widely available in nephrology units. The nutritional management should not be forgotten because there is a resistance to anabolism and protein intake should be involved in physical activity program. Associated treatments should not be neglected: vitamin D, anti-inflammatory, androgens. Some are still under evaluation. Therapeutic option, tomorrow, could be anti-myostatin antibodies and glitazones.

What factors influence protein synthesis and degradation in critical illness?

PURPOSE OF REVIEW

The optimal approach to improve protein metabolism in critical illness is not yet fully defined. Here, we have summarized recent literature dealing with the main catabolic and anabolic factors influencing protein kinetics in acute hypercatabolic patients.

RECENT FINDINGS

Protein/amino acid intake levels should be adapted to type and severity of illness, keeping in mind that energy overfeeding is associated with poor outcome. A number of anticatabolic nutraceuticals and drugs have been tested in acute patients. The encouraging results have been obtained with β-hydroxy-β-methylbutyrate, omega-3 fatty acids, oxandrolone, propranolol, and metformin. Their efficacy and lack of side-effects need to be confirmed. Physical therapy, including muscle electro-stimulation, appears a very promising intervention, both effective and safe.

SUMMARY

Protein catabolism can be minimized in acute patients by adequate nutritional support, early mobilization, and, possibly, pharmacological and nutraceutical interventions. A combination of these strategies should be tested in randomized controlled trials.

Efficacy and Safety of Leucine Supplementation in the Elderly

Leucine supplementation has grown in popularity due to the discovery of its anabolic effects on cell signaling and protein synthesis in muscle. The current recommendation is a minimum intake of 55 mg ⋅ kg^-1. d^-1 Leucine acutely stimulates skeletal muscle anabolism and can overcome the anabolic resistance of aging. The value of chronic leucine ingestion for muscle growth is still unclear. Most of the research into leucine consumption has focused on efficacy. To our knowledge, very few studies have sought to determine the maximum safe level of intake. Limited evidence suggests that intakes of ≤1250 mg ⋅ kg^-1. d^-1 do not appear to have any health consequences other than short-term elevated plasma ammonia concentrations. Similarly, no adverse events have been reported for the leucine metabolite β-hydroxy-β-methylbutyrate (HMB), although no studies have tested HMB toxicity in humans. Therefore, future research is needed to evaluate leucine and HMB toxicity in the elderly and in specific health conditions.

Soy-Dairy Protein Blend or Whey Protein Isolate Ingestion Induces Similar Postexercise Muscle Mechanistic Target of Rapamycin Complex 1 Signaling and Protein Synthesis Responses in Older Men

Background: Previous work demonstrated that a soy-dairy protein blend (PB) prolongs hyperaminoacidemia and muscle protein synthesis in young adults after resistance exercise.

Objective: We investigated the effect of PB in older adults. We hypothesized that PB would prolong hyperaminoacidemia, enhancing mechanistic target of rapamycin complex 1 (mTORC1) signaling and muscle protein anabolism compared with a whey protein isolate (WPI).

Methods: This double-blind, randomized controlled trial studied men 55–75 y of age. Subjects consumed 30 g protein from WPI or PB (25% soy, 25% whey, and 50% casein) 1 h after leg extension exercise (8 sets of 10 repetitions at 70% one-repetition maximum). Blood and muscle amino acid concentrations and basal and postexercise muscle protein turnover were measured by using stable isotopic methods. Muscle mTORC1 signaling was assessed by immunoblotting.

Results: Both groups increased amino acid concentrations (P < 0.05) and mTORC1 signaling after protein ingestion (P < 0.05). Postexercise fractional synthesis rate (FSR; P ≥ 0.05), fractional breakdown rate (FBR; P ≥ 0.05), and net balance (P = 0.08) did not differ between groups. WPI increased FSR by 67% (mean ± SEM: rest: 0.05% ± 0.01%; postexercise: 0.09% ± 0.01%; P < 0.05), decreased FBR by 46% (rest: 0.17% ± 0.01%; postexercise: 0.09% ± 0.03%; P < 0.05), and made net balance less negative (P < 0.05). PB ingestion did not increase FSR (rest: 0.07% ± 0.03%; postexercise: 0.09% ± 0.01%; P ≥ 0.05), tended to decrease FBR by 42% (rest: 0.25% ± 0.08%; postexercise: 0.15% ± 0.08%; P = 0.08), and made net balance less negative (P < 0.05). Within-group percentage of change differences were not different between groups for FSR, FBR, or net balance (P ≥ 0.05).

Conclusions: WPI and PB ingestion after exercise in older men induced similar responses in hyperaminoacidemia, mTORC1 signaling, muscle protein synthesis, and breakdown. These data add new evidence for the use of whey or soy-dairy PBs as targeted nutritional interventions to counteract sarcopenia. This trial was registered at clinicaltrials.gov as NCT01847261.

Branched chain amino acid metabolic reprogramming in heart failure

Metabolic remodeling is a hall-mark of cardiac maturation and pathology. The switch of substrate utilization from glucose to fatty acid is observed during post-natal maturation period in developing heart, but the process is reversed from fatty acids to glucose in the failing hearts across different clinic and experimental models. Majority of the current investigations have been focusing on the regulatory mechanism and functional impact of this metabolic reprogramming involving fatty acids and carbohydrates. Recent progress in metabolomics and transcriptomic analysis, however, revealed another significant remodeled metabolic branch associated with cardiac development and disease, i.e. Branched-Chain Amino Acid (BCAA) catabolism. These findings have established BCAA catabolic deficiency as a novel metabolic feature in failing hearts with potentially significant impact on the progression of pathological remodeling and dysfunction. In this review, we will evaluate the current evidence and potential implication of these discoveries in the context of heart diseases and novel therapies. This article is part of a Special Issue entitled: The role of post-translational protein modifications on heart and vascular metabolism edited by Jason R.B. Dyck & Jan F.C. Glatz.

Sarcopenia is a risk factor for the recurrence of hepatocellular carcinoma after curative treatment

BACKGROUND AND AIM

Sarcopenia, initially proposed as decreased of muscle mass and strength, is associated with aging and malignant diseases. The aim of the present study was to determine whether there is a correlation between sarcopenia and the recurrence of hepatocellular carcinoma (HCC) after curative treatment.

METHODS

We conducted a retrospective analysis of consecutive naive patients with HCC who underwent curative resection or radiofrequency ablation. To eliminate the influence of cause or the severity of liver damage, subjects were limited to those with HCC with hepatitis C-related cirrhosis and Child-Pugh class A liver function. Patients were assessed using computed tomographic measurement of muscle mass at the level of the third lumbar (L3) vertebrae, the L3 skeletal muscle index (L3 SMI). Sarcopenia was defined by using previously published, sex-specific cut-off value.

RESULTS

Sarcopenia was present in 61 of 92 patients. Patients' median age was 71.5 years (range, 47-84), and the baseline characteristics of patients were comparable between patients with and without sarcopenia except for sex, serum albumin level, prothrombin time, diabetes mellitus and body mass index. Recurrence rates at 1, 3 and 5 years were 39.1%,77.1%,81.7% for patients with sarcopenia and 23.5%,59.5% and 75.7% for patients without sarcopenia, respectively (P = 0.03). Multivariate Cox analysis revealed that sarcopenia and preoperative α-fetoprotein of more than 40 ng/mL were significant independent factors for recurrence.

CONCLUSION

Sarcopenia is a risk factor for recurrence in patients with HCC who were treated with curative treatment.

Muscle wasting in ageing and chronic illness

PURPOSE

As life expectancy increases, muscle wasting is becoming a more and more important public health problem. This review summarizes the current knowledge of pathophysiological mechanisms underlying muscle loss in ageing and chronic diseases such as heart failure and discusses evolving interventional strategies.

RECENT FINDINGS

Loss of skeletal muscle mass and strength is a common phenomenon in a wide variety of disorders associated with ageing and morbidity-associated catabolic conditions such as chronic heart failure. Muscle wasting in ageing but otherwise healthy human beings is referred to as sarcopenia. Unlike cachexia in advanced stages of chronic heart failure, muscle wasting per se is not necessarily associated with weight loss. In this review, we discuss pathophysiological mechanisms underlying muscle loss in sarcopenia and cachexia, highlight similarities and differences of both conditions, and discuss therapeutic targets and possible treatments, such as exercise training, nutritional support, and drugs. Candidate drugs to treat muscle wasting disease include myostatin antagonists, ghrelin agonists, selective androgen receptor molecules, megestrol acetate, activin receptor antagonists, espindolol, and fast skeletal muscle troponin inhibitors.

SUMMARY

Present approaches to muscle wasting disease include exercise training, nutritional support, and drugs, although particularly the latter remain currently restricted to clinical studies. Optimizing skeletal muscle mass and function in ageing and chronic illness including heart failure is one of the chapters that are far from finished and gains future potential for new therapeutic interventions to come.