Effects of beta-hydroxy-beta-methylbutyrate (HMB) on exercise performance and body composition across varying levels of age, sex, and training experience: A review

Host-microbe interactions rewire metabolism in a C. elegans model of leucine breakdown deficiency

In humans, defects in leucine catabolism cause a variety of inborn errors in metabolism. Here, we use Caenorhabditis elegans to investigate the impact of mutations in mccc-1, an enzyme that functions in leucine breakdown. Through untargeted metabolomic and transcriptomic analyses we find extensive metabolic rewiring that helps to detoxify leucine breakdown intermediates via conversion into previously undescribed metabolites and to synthesize mevalonate, an essential metabolite. We also find that the leucine breakdown product 3,3-hydroxymethylbutyrate (HMB), commonly used as a human muscle-building supplement, is toxic to C. elegans and that bacteria modulate this toxicity. Unbiased genetic screens revealed interactions between the host and microbe, where components of bacterial pyrimidine biosynthesis mitigate HMB toxicity. Finally, upregulated ketone body metabolism genes in mccc-1 mutants provide an alternative route for biosynthesis of the mevalonate precursor 3-hydroxy-3-methylglutaryl-CoA. Our work demonstrates that a complex host-bacteria interplay rewires metabolism to allow host survival when leucine catabolism is perturbed.

De novo biosynthesis of 3-hydroxy-3-methylbutyrate as anti-catabolic supplement by metabolically engineered Escherichia coli

3-Hydroxy-3-methylbutyrate (HMB) is a five-carbon branch-chain hydroxy acid currently used as a dietary supplement to treat sarcopenia and exercise training. However, its current production relies on conventional chemical processes which require toxic substances and are generally non-sustainable. While bio-based syntheses of HMB have been developed, they are dependent on biotransformation of its direct precursors which are generally costly. Therefore, in this work, we developed a synthetic de novo HMB biosynthetic pathway that enables HMB production from renewable resources. This novel HMB biosynthesis employs heterologous enzymes from mevalonate pathway and myxobacterial iso-fatty acid pathway for converting acetyl-CoA to HMB-CoA. Subsequently, HMB-CoA is hydrolyzed by a thioesterase to yield HMB. Upon expression of this pathway, our initial Escherichia coli strain produced 660 mg/L of HMB from glucose in 48 hours. Through optimization of coenzyme A removal from HMB-CoA and genetic operon structure, our final strain achieved HMB production titer of 17.7 g/L in glucose minimal media using a bench-top bioreactor. This engineered strain was further demonstrated to produce HMB from other renewable carbon sources such as xylose, glycerol, and acetate. The results from this work provided a flexible and environmentally benign method for producing HMB.

Anabolic Strategies for ICU-Acquired Weakness. What Can We Learn from Bodybuilders?

The study aimed to show the potential clinical application of supplements used among sportsmen for patients suffering from Intensive Care Unit-acquired Weakness (ICUAW) treatment. ICUAW is a common complication affecting approximately 40% of critically ill patients, often leading to long-term functional disability. ICUAW comprises critical illness polyneuropathy, critical illness myopathy, or a combination of both, such as critical illness polyneuromyopathy. Muscle degeneration begins shortly after the initiation of mechanical ventilation and persists post-ICU discharge until proteolysis and autophagy processes normalize. Several factors, including prolonged bedrest and muscle electrical silencing, contribute to muscle weakness, resulting from an imbalance between protein degradation and synthesis. ICUAW is associated with tissue hypoxia, oxidative stress, insulin resistance, reduced glucose uptake, lower adenosine triphosphate (ATP) formation, mitochondrial dysfunction, and increased free-radical production. Several well-studied dietary supplements and pharmaceuticals commonly used by athletes are proven to prevent the aforementioned mechanisms or aid in muscle building, regeneration, and maintenance. While there is no standardized treatment to prevent the occurrence of ICUAW, nutritional interventions have demonstrated the potential for its mitigation. The use of ergogenic substances, popular among muscle-building sociates, may offer potential benefits in preventing muscle loss and aiding recovery based on their work mechanisms.

Supplementation with β-hydroxy-β-methylbutyrate after resistance training in post-acute care patients with sarcopenia: A randomized, double-blind placebo-controlled trial

OBJECTIVES

This study aimed to evaluate the efficacy of adding β-hydroxy-β- methylbutyrate (HMB) supplementation to a 12-week exercise-based rehabilitation program in older adults with sarcopenia after discharge from a post-acute geriatric rehabilitation unit.

STUDY DESIGN

A randomized, double-blind, placebo-controlled trial with two parallel groups. The intervention group received 3 g/day of Ca-HMB and participated in a 12- week resistance training program (3 sessions/week). The control group received a placebo and followed the same training program.

MAIN OUTCOME MEASURES

The primary outcomes were the improvements of handgrip strength and physical performance assessed through the Short Physical Performance Battery (SPPB) and 4-meter gait speed; and handgrip strength. All variables were assessed at baseline, post-intervention, and 1-year follow-up.

RESULTS

After completing the 12-week exercise program, the intervention group showed significant improvements in SPPB-Balance (1.3, 95 %CI 0.3 to 2.4) and total SPPB score (2.2, 95 %CI 0.4 to 4.0). Intra-group analysis demonstrated gains in the SPPB-Chair Stand (0.7 points, 95 %CI 0.0 to 1.4) and total SPPB score (2.1 points, 95 %CI 0.3 to 3.9) in the intervention group. Improvements in handgrip strength were observed in women (3.7 kg, 95 %CI: 0.2 to 7.3) at the end of the intervention, and persisted at the 1-year follow-up.

CONCLUSIONS

Our findings suggest that the supplementation of 3 g/day of Ca-HMB with resistance exercise may significantly enhance muscle strength and physical performance among older women with sarcopenia after recent hospitalization. Given this study's limitations, the intervention's effectiveness cannot be drawn, and further studies are needed.

Effects of HMB on Endurance Performance in a Healthy Population: A Systematic Review and Meta-Analysis

ABSTRACT

Fernández-Landa, J, Todorovic, N, Santibañez-Gutierrez, A, Ostojic, SM, Calleja-González, J, Sekulic, D, and Mielgo-Ayuso, J. Effects of HMB on endurance performance in a healthy population: a systematic review and meta-analysis. J Strength Cond Res 38(4): e202-e210, 2024-β-hydroxy-β-methylbutyrate (HMB) has been used extensively as a dietary supplement for athletes and physically active people. However, the ergogenic effect of HMB supplementation on endurance performance is still unclear. Therefore, this systematic review and meta-analysis (SRMA) aimed to assess HMB supplementation on endurance performance and V̇O 2 max . This SRMA followed PRISMA guidelines. Three electronic databases were searched (PubMed/Medline, Web of Science [WOS], and Scopus) from inception until April 3, 2023. In this SRMA, human experimental trials, controlled with a placebo group, assessing the effect of HMB supplementation on endurance performance in a healthy population were included. The quality of the studies was assessed by the Physiotherapy Evidence Database (PEDro) scale. The study protocol was registered in the Prospective Register of Systematic Review (PROSPERO): CRD42022341790. Eleven studies involving 279 participants met the inclusion criteria. The results displayed a significant improvement on endurance performance (pooled standardized mean difference [SMD] = 0.58 [0.28-0.87]) and V̇O 2 max (pooled SMD = 0.58 [0.21-0.95]) after HMB ingestion. Moreover, after the exclusion of the studies not evenly distributed around the base of the funnel plot, the results continued to be significantly positive in endurance performance (pooled SMD = 0.38 [0.22-0.53]) and V̇O 2 max (pooled SMD = 0.25 [0.09-0.42]). In conclusion, HMB (3 g·d -1 ) ingestion during 2-12 weeks significantly improves endurance performance and V̇O 2 max .

Case report of belt electrode-skeletal muscle electrical stimulation for acute heart failure with severe obesity: a novel therapeutic option for acute phase rehabilitation

Background

Belt electrode skeletal muscle electrical stimulation (B-SES) is an emerging therapy anticipated to yield more favorable outcomes than conventional neuromuscular electrical stimulation (NMES), owing to its larger stimulation area. However, information on its efficacy and safety in patients with heart failure remains limited.

Case presentation

A 43-year-old man with a body mass index of 41 kg/m2 was admitted to our hospital for acute heart failure due to dilated cardiomyopathy. The patient required prolonged catecholamine support owing to poor cardiac function, and heart transplantation was considered. We initiated a mobilization program, but the patient's mobility was highly limited due to severe obesity and symptomatic orthostatic hypotension. B-SES was introduced to accomplish weight loss and early ambulation. We applied an intensive monitoring program for safe use and modulated the intensity of B-SES according to physical function. During the B-SES program, the patient's body weight decreased from 89.6 kg to 78.6 kg. Sequential evaluations of body composition and skeletal muscle ultrasonography revealed improved muscle mass, quality, and physical function. Furthermore, we explored the workload of B-SES using expiratory gas analysis. No adverse events were observed during B-SES.

Discussion

We successfully used B-SES to improve muscle function and morbidity in the treatment of acute heart failure. B-SES could be an option for patients with heart failure who have limited mobility and obesity.

The Role of Amino Acid Supplementation in Orthopaedic Surgery

The nutritional status of patients undergoing orthopaedic surgery has started to garner increasing attention in published literature. Notable previous evidence has demonstrated the negative effect of malnutrition on outcomes after orthopaedic procedures. Although there has been increased recognition of malnutrition as a risk factor for suboptimal outcomes, the use of nutritional supplementation to mitigate those risks is not well understood. The purpose of this review of most current literature on the topic is to introduce and elucidate the role of amino acid supplementation as a countermeasure to muscle loss and improvement of nutritional status in orthopaedic patients to improve results and outcomes after orthopaedic surgery.

Early detection and assessment of intensive care unit-acquired weakness: a comprehensive review

Intensive care unit-acquired weakness (ICU-AW) is a serious complication in critically ill patients. Therefore, timely and accurate diagnosis and monitoring of ICU-AW are crucial for effectively preventing its associated morbidity and mortality. This article provides a comprehensive review of ICU-AW, focusing on the different methods used for its diagnosis and monitoring. Additionally, it highlights the role of bedside ultrasound in muscle assessment and early detection of ICU-AW. Furthermore, the article explores potential strategies for preventing ICU-AW. Healthcare providers who manage critically ill patients utilize diagnostic approaches such as physical exams, imaging, and assessment tools to identify ICU-AW. However, each method has its own limitations. The diagnosis of ICU-AW needs improvement due to the lack of a consensus on the appropriate approach for its detection. Nevertheless, bedside ultrasound has proven to be the most reliable and cost-effective tool for muscle assessment in the ICU. Combining the Sequential Organ Failure Assessment (SOFA) score, Acute Physiology and Chronic Health Evaluation (APACHE) II score assessment, and ultrasound can be a convenient approach for the early detection of ICU-AW. This approach can facilitate timely intervention and prevent catastrophic consequences. However, further studies are needed to strengthen the evidence.

Anthropometric and Body Circumference Determinants for Hand Grip Strength: A Population-Based Mon-Timeline Study

Background

Hand grip strength (HGS) is a tool for diagnosing sarcopenia. In this study, we examined some anthropometric and body circumference measurements as determinants for HGS.

Methods

This cross-sectional study was conducted with participants (Mongolians, n = 1080, aged 18-70, mean age of 41.2 ± 13.9 years, 33.7% of men) from the "Mon-Timeline" cohort study. To measure HGS, a digital grip strength dynamometer was used.

Results

Mean HGS in men was 40.1 ± 10.4 kg and in women was 24.5 ± 5.6 kg. Correlation analysis showed that the strongest correlation with HGS was height (r = 0.712, p < 0.001). Moreover, HGS was inversely correlated with age (r = -0.239, p < 0.001) and thigh circumference (r = -0.070, p < 0.01), while it was positively correlated with body weight (r = 0.309, p < 0.001), neck circumference (r = 0.427, p < 0.001), upper arm circumference (r = 0.108, p < 0.0001), lower arm circumference (r = 0.413, p < 0.0001), and calf circumference (r = 0.117, p < 0.0001). In the multivariate linear regression analysis (unstandardized B coefficient, 95% CI), age (-0.159, -0.188; -0.129), sex (-9.262, -10.459; -8.064), height (0.417, 0.357; 0.478), lower arm circumference (1.003, 0.736; 1.270), and calf circumference (-0.162, -0.309; -0.015) were significantly associated with HGS.

Conclusions

When detecting sarcopenia using HGS, it is important to take into account variables such as body height and body circumference.

Effects of β-hydroxy-β-methylbutyrate supplementation on recovery from exercise-induced muscle damage: a mini-review

PURPOSE

Several studies have reported that β-hydroxy-β-methylbutyrate (HMB) has beneficial effects on exercise-induced muscle damage (EIMD). Here, we examine the effects and mechanisms of HMB supplementation on exercise-induced muscle damage EIMD and provide guidelines for the application of supplementary HMB.

METHODS

For this review, we performed web searches using PubMed, Web of Science, and Wiley Online Library. Keywords used were 'HMB,' 'HMB and EIMD,' 'HMB and recovery,' 'HMB and resistance exercise,' and 'HMB and eccentric muscle contraction.'

RESULTS

Several previous studies have shown that HMB supplementation can reduce EIMD and promote recovery. In particular, reductions were detected in certain markers of muscle membrane damage, including creatine kinase and lactate dehydrogenase. There may be multiple mechanisms in which HMB supplementation reduces EIMD, including reducing muscle-damage-induced inflammation and oxidative stress and promoting cellular cholesterol synthesis by increasing the production of β-hydroxy-β-methylglutaryl-Co-A, a product of HMB metabolism. In general, the suggested daily intake of HMB is 3 g. In addition, the timing and duration of HMB intake can be classified as chronic [≥ 2 weeks, in which a total of 3 g is consumed daily (3 × 1 g taken at breakfast, lunch, and dinner)] or acute (taken 30-60 min before exercise). The timing of intake during exercise may vary depending upon whether the formulation is calcium HMB (60-120 min before exercise) or the free-acid form of HMB (30-60 min before exercise). Notably, the co-administration of HMB and creatine does not appear to be effective in reducing EIMD.

CONCLUSION

HMB supplementation can be considered as an effective nutritional strategy to minimize EIMD.

Metabolomics in Team-Sport Athletes: Current Knowledge, Challenges, and Future Perspectives

Metabolomics is a promising tool for studying exercise physiology and exercise-associated metabolism. It has recently been defined with the term “sportomics” due to metabolomics’ capability to characterize several metabolites in several biological samples simultaneously. This narrative review on exercise metabolomics provides an initial and brief overview of the different metabolomics technologies, sample collection, and further processing steps employed for sport. It also discusses the data analysis and its biological interpretation. Thus, we do not cover sample collection, preparation, and analysis paragraphs in detail here but outline a general outlook to help the reader to understand the metabolomics studies conducted in team-sports athletes, alongside endeavoring to recognize existing or emergent trends and deal with upcoming directions in the field of exercise metabolomics in a team-sports setting.

Low carbohydrate high fat flour: its rheology, bread making, physico-sensory and staling characteristics

A low carbohydrate and high fat (LCHF) flour was developed by combining almond flour, desiccated coconut flour, defatted soya flour, dry gluten powder, psyllium husk and skimmed milk powder. Determination of rheological, bread making, nutritional, and staling characteristics of LCHF flour in comparison with wheat flour (WF) was studied. The results showed that LCHF flour had lower amylograph pasting temperature (31.6 °C), peak viscosity (200 BU), farinograph dough stability (0.8 min), and bread volume (315 ml) compared to WF (61.0 °C; 782 BU; 8.7 min; and 525 ml) respectively. The use of additive mixes such as fungal alpha-amylase, sodium stearoyl-2-lactylate and xanthan gum, improved the volume and texture of the LCHF bread. Scanning electron microscope images showed little or no presence of starch granules in LCHF dough and bread. Differential scanning calorimetry studies indicated that, during storage (1-5 days), the enthalpy for gelatinization of endotherm starch increased (0.71-3.40 j/g) in WF bread, however, in LCHF bread this increase was lesser (0.53 to 2.2 j/g) indicating slower staling rate in LCHF bread. The LCHF bread showed lower carbohydrate (13.7%), in-vitro starch digestibility (17.3%) and staling rate, higher protein (22.51%), fat (11.01%), and medium-chain fatty acids than WF bread (51.9%; 38.2%; 12.57%; 3.78%) respectively. The results showed that the developed product would be beneficial for people suffering from diabetics and obesity.

Adherence to Low-Carbohydrate Diets in Patients with Diabetes: A Narrative Review

Evidence suggests that low carbohydrate (<130 g/day of carbohydrate) (LCD) and very low carbohydrate, ketogenic diets (typically <50 g/day of carbohydrate) (VLCKD) can be effective tools for managing diabetes given their beneficial effects on weight loss and glycemic control. VLCKD also result in favorable lipid profile changes. However, these beneficial effects can be limited by poor dietary adherence. Cultural, religious, and economic barriers pose unique challenges to achieving nutritional compliance with LCD and VLCKD. We review the various methods for assessing adherence in clinical studies and obstacles posed, as well as potential solutions to these challenges.

Effects of exercise and/or β-hydroxy-β-methylbutyrate supplementation on muscle mass, muscle strength, and physical performance in older women with low muscle mass: a randomized, double-blind, placebo-controlled trial

BACKGROUND

The interaction between exercise and nutritional supplementation is unclear among older adults at risk of sarcopenia.

OBJECTIVES

We aimed to examine if β-hydroxy-β-methylbutyrate (HMB) supplementation enhances the effects of exercise on muscle mass, strength, and physical performance and observe potential residual effects in older women with low muscle mass.

METHODS

This 12-wk, randomized, double-blind, placebo-controlled, 2 × 2 factorial design (exercise-only, HMB-only, both, and none) trial included 156 women aged 65-79 y with skeletal muscle index <5.7 kg/m2, and was followed by a 12-wk observational period. Resistance training twice weekly or education programs every 2 wk and calcium-HMB (1500 mg) or placebo supplements daily were provided. The primary outcome was the change in muscle mass from baseline to postintervention. Secondary outcomes included changes in muscle strength and physical performance.

RESULTS

In total, 149 and 144 participants completed the assessment at weeks 12 and 24, respectively. ANOVAs based on the intention-to-treat principle showed no significant interactions between exercise and HMB on any primary outcomes. The main-effect analyses revealed that exercise improved the usual and maximal gait speed by 0.16 m/s (95% CI: 0.10, 0.21 m/s) and 0.15 m/s (95% CI: 0.09, 0.22 m/s), respectively; the knee extensor and hip adductor strength by 22.0 N (95% CI: 10.1, 33.9 N) and 21.8 N (95% CI: 12.9, 30.7 N), respectively; and timed up-and-go and sit-to-stand time by -0.5 s (95% CI: -0.7, -0.3 s) and -1.7 s (95% CI: -2.1, -1.3 s), respectively, relative to education. HMB improved usual gait speed by 0.06 m/s (95% CI: 0.01, 0.11 m/s) relative to placebo. Most improvements disappeared during the subsequent 12-wk observation period.

CONCLUSIONS

HMB additively improved gait performance with negligible benefit and provided no enhancements in the effects of exercise on other outcomes. Exercise appeared to be the only effective intervention to improve outcomes in older women with low muscle mass.This trial was registered at www.umin.ac.jp/ctr/as UMIN000028560.

Pharmacological Treatment of Sarcopenia

Sarcopenia has been acquiring a growing importance in the scientific literature and in doctors' offices. As the population ages, it becomes increasingly essential to know, prevent, and treat this clinical condition. The purpose of the present review is to bring up the current evidence on the diagnosis of this pathology, in a practical way, as well as the main current treatment options.

The Effects of 12-Week Beta-Hydroxy-Beta-Methylbutyrate Supplementation in Patients with Liver Cirrhosis: Results from a Randomized Controlled Single-Blind Pilot Study

Background and Aim: Sarcopenia is considered an important risk factor for morbidity and mortality in liver cirrhosis. Beta-hydroxy-beta-methylbutyrate (HMB) has the potential to increase muscle mass and performance by stimulating protein synthesis and reducing muscle catabolism. The present study aimed at evaluating the effect of HMB supplementation on muscle mass and function in patients with liver cirrhosis. Changes in frailty during the study were also estimated, and the safety of HMB supplementation was verified. Methods: This is a randomized, single-blind, placebo-controlled pilot trial. Twenty-four patients (14 HMB and 10 placebo) affected by liver cirrhosis were enrolled in the study. Each patient received dedicated counseling, which included nutrition and physical activity recommendations for chronic liver disease patients. Patients were randomized to receive 3 g/day of HMB or placebo (sorbitol powder) for 12 consecutive weeks. A diet interview, anthropometry, electrical bioimpedance analysis (BIA), quadriceps ultrasound, physical performance battery, Liver Frailty Index (LFI), and cognitive tests were completed at enrolment (T0), at 12 weeks (T1), and 24 weeks after enrolment (T2). Results: At baseline, the two groups were similar in demography, severity of liver disease, muscle mass, muscle function, and cognitive tests. LFI at baseline was higher in patients in the HMB group vs. those in the placebo group (4.1 ± 0.4 vs. 3.4 ± 0.6, p < 0.01). After treatment, a statistically significant increase in muscle function was seen in the HMB group (chair stand test: 14.2 ± 5 s vs. 11.7 ± 2.6 s, p < 0.05; six-minute walk test: 361.8 ± 68 m vs. 409.4 ± 58 m, p < 0.05). Quadriceps muscle mass measured by ultrasound also increased (4.9 ± 1.8 vs. 5.4 ± 1.8 mm, p < 0.05) after HMB, while LFI decreased (4.1 ± 0.4 vs. 3.7 ± 0.4, p < 0.05). HMB was well tolerated by patients, and no adverse events were documented. Conclusions: Our study suggests the efficacy of 12-week beta-hydroxy-beta-methylbutyrate supplementation in promoting improvements in muscle performance in compensated cirrhotic patients. LFI was also ameliorated. Further studies with a greater number of patients are required to reinforce this hypothesis.

Metabolomics Signatures of Aging: Recent Advances

Metabolomics is the latest state-of-the-art omics technology that provides a comprehensive quantitative profile of metabolites. The metabolites are the cellular end products of metabolic reactions that explain the ultimate response to genomic, transcriptomic, proteomic, or environmental changes. Aging is a natural inevitable process characterized by a time-dependent decline of various physiological and metabolic functions and are dominated collectively by genetics, proteomics, metabolomics, environmental factors, diet, and lifestyle. The precise mechanism of the aging process is unclear, but the metabolomics has the potential to add significant insight by providing a detailed metabolite profile and altered metabolomic functions with age. Although the application of metabolomics to aging research is still relatively new, extensive attempts have been made to understand the biology of aging through a quantitative metabolite profile. This review summarises recent developments and up-to-date information on metabolomics studies in aging research with a major emphasis on aging biomarkers in less invasive biofluids. The importance of an integrative approach that combines multi-omics data to understand the complex aging process is discussed. Despite various innovations in metabolomics and metabolite associated with redox homeostasis, central energy pathways, lipid metabolism, and amino acid, a major challenge remains to provide conclusive aging biomarkers.

Biosynthesis of 3-Hydroxy-3-Methylbutyrate from l-Leucine by Whole-Cell Catalysis

3-Hydroxy-3-methylbutyrate (HMB) is an important compound that can be used for the synthesis of a variety of chemicals in the food and pharmaceutical fields. Here, a biocatalytic method using l-leucine as a substrate was designed and constructed by expressing l-amino acid deaminase (l-AAD) and 4-hydroxyphenylpyruvate dioxygenase (4-HPPD) in Escherichia coli. To reduce the influence of the rate-limiting step on the cascade reaction, two 4-HPPD mutants were screened by rational design and both showed improved catalytic activity. Under optimal reaction conditions, the maximum conversion rate and production rate were 80% and 0.257 g/L·h, respectively. HMB production could be realized with high efficiency without an additional supply of adenosine triphosphate (ATP), which successfully overcomes the shortcomings of chemical production and fermentation methods. This design-based strategy of constructing a whole-cell catalyst system from l-leucine might serve as an alternative route to HMB synthesis.

Effects of Co-Ingestion of β-Hydroxy-β-Methylbutyrate and L-Arginine α-Ketoglutarate on Jump Performance in Young Track and Field Athletes

The aim of the study was to determine the effect of simultaneous supplementation of β-hydroxy-β-methylbutyrate and L-Arginine α-ketoglutarate on lower limb power and muscle damage in medium distance runners aged 15.3 (±0.9) years old. Methods: The study group consisted of 40 volunteers aged 14–17 years practicing medium distance running for at least two years. The study lasted 12 days and followed a randomized, double-blind, placebo-controlled, parallel design. All subjects attended a familiarization session on day 0 before the test. The subjects were randomly divided into two groups: supplements and placebo group. The same training cycle protocol was used in both groups during the 12-day training period. Morning warm-up involved 10 min jogging at 60–75% of maximal heart rate and countermovement jump height measurement. Main training units were carried out for both groups with the same volume. Training load assessment (the daily session Rating of Perceived Exertion (s-RPE) method) method takes into consideration the intensity and the duration of the training session to calculate the “training load” (TL). Results: At the end of the training cycle, a significant (p = 0.002) decrease in the countermovement jump (CMJ) height was found in the placebo group when compared to the baseline. In the supplement group, there was no decrease in the countermovement jump height. Creatine kinase and lactate dehydrogenase concentration increased during the training days similarly in both groups and decreased on rest days. There were no differences between groups in enzymes concentration. The research results indicate that the supplement combination used in the supplements group prevented a reduction in the CMJ values. In contrast to the supplements group, in the placebo group, the CMJ changes were statistically significant: a noticeable (p = 0.002) decrease in CMJ was noted between the baseline measurement and the 6th measurement. The well-being of the subjects from both groups changed significantly during the training period, and the intergroup differences in the mood level were similar and not statistically significant. Conclusions: The results of this study indicate that the daily co-supplementation with calcium salt of β-hydroxy-β-methylbutyrate (7.5 g) and L-Arginine α-ketoglutarate (10 g) during training might help to prevent decline in jump performance. No influence on muscle damage markers or mood was shown.

Effect of a Food for Special Medical Purposes for Muscle Recovery, Consisting of Arginine, Glutamine and Beta-Hydroxy-Beta-Methylbutyrate on Body Composition and Skin Health in Overweight and Obese Class I Sedentary Postmenopausal Women

The consumption of dietary amino acids has been evaluated for therapeutic and safety intervention in obesity. In particular, three molecules have been shown to be effective: arginine, glutamine and leucine (and its metabolite beta-hydroxy-beta-methylbutyrate, HMB). This randomized, double-blinded pilot study in obese postmenopausal patients aimed to evaluate the efficacy of the administration of a specific food for special medical purposes (FSMP) consisting of arginine, glutamine and HMB on body composition, in particular, visceral adipose tissue (VAT), assessed by dual-energy X-ray absorptiometry (DXA), as the primary endpoint. The secondary endpoint was to evaluate the effects on skin health through a validated self-reported questionnaire. A significant improvement on VAT of Δ = -153.600, p = 0.01 was recorded in the intervention group. Skin health showed a significant improvement in the treatment group for the following: bright Δ = 1.400 (0.758; 2.042), elasticity Δ = 0.900 (0.239; 1.561), wrinkles Δ = 0.800 (0.276; 1.324), and on total score, Δ = 3.000 (1.871; 4.129). In the intervention group, the improvement in VAT was associated with an improvement in the bright score (r = -0.58; p = 0.01). In conclusion, this study demonstrated that the intake for 4-weeks of arginine, glutamine and HMB effects a significant reduction in VAT and improves skin condition, while fat free mass (FFM) is maintained, thus achieving "high-quality" weight loss.

Frailty syndrome: A target for functional nutrients?

Frailty is a late life phenotype characterized by a decline in physiological reserve across several organ systems, resulting in the increased susceptibility to endogenous and/or exogenous stressors. Although the etiology of frailty remains poorly understood, an interconnected network of putative mechanisms linked to the ageing process has been proposed. However, frailty is a dynamic process that may be prevented, delayed, or even reversed. The syndromic nature of frailty requires a multidomain approach, such as proper nutrition, as part of modifiable environmental factors, and represents one of the most promising and least costly ways to prevent and reduce frailty among older adults. Nutrient deficiencies have been consistently associated with frailty; however, mounting evidence also supports the hypothesis that beyond the traditional nutritional value, specific dietary components may exert function-enhancing effects and mitigate the extent of frailty. Thus, further mechanistic studies, along with large clinical trials, are imperative to establish the exact role of functional nutrients in the clinical management of frailty. Here, we provide a contemporary discussion of how emerging functional nutrients may contribute to modify the trajectory of the frailty syndrome.

Nutritional Interventions in Cancer Cachexia: Evidence and Perspectives From Experimental Models

Cancer cachexia is a complex metabolic syndrome characterized by involuntary skeletal muscle loss and is associated with poor clinical outcome, decreased survival and negatively influences cancer therapy. No curative treatments are available for cancer cachexia, but nutritional intervention is recommended as a cornerstone of multimodal therapy. Optimal nutritional care is pivotal in the treatment of cancer cachexia, and the effects of nutrients may extend beyond provision of adequate energy uptake, targeting different mechanisms or metabolic pathways that are affected or deregulated by cachexia. The evidence to support this notion derived from nutritional intervention studies in experimental models of cancer cachexia is systematically discussed in this review. Moreover, experimental variables and readout parameters to determine skeletal muscle wasting and cachexia are methodologically evaluated to allow critical comparison of similar studies. Single- and multinutrient intervention studies including qualitative modulation of dietary protein, dietary fat, and supplementation with specific nutrients, such as carnitine and creatine, were reviewed for their efficacy to counteract muscle mass loss and its underlying mechanisms in experimental cancer cachexia. Numerous studies showed favorable effects on impaired protein turnover and related metabolic abnormalities of nutritional supplementation in parallel with a beneficial impact on cancer-induced muscle wasting. The combination of high quality nutrients in a multitargeted, multinutrient approach appears specifically promising, preferentially as a multimodal intervention, although more studies investigating the optimal quantity and combination of nutrients are needed. During the review process, a wide variation in timing, duration, dosing, and route of supplementation, as well as a wide variation in animal models were observed. Better standardization in dietary design, and the development of experimental models that better recapitulate the etiology of human cachexia, will further facilitate successful translation of experimentally-based multinutrient, multimodal interventions into clinical practice.

Altered metabolomic profiling of overweight and obese adolescents after combined training is associated with reduced insulin resistance

Exercise training and a healthy diet are the main non-pharmacological strategies for treating chronic conditions, such as obesity and insulin resistance (IR), in adolescents. However, the isolated metabolic changes caused by exercise training without dietary intervention have not yet been established. We investigated how combined training (CT) without dietary intervention altered the concentrations of serum metabolites, biochemical, anthropometric and functional parameters in overweight and obese adolescents. Thirty-seven adolescents (14.6 ± 1.05 years), of both sexes, were randomly assigned to the control group (CG, n = 19) or the training group (TG, n = 18). The CT was composed by resistance training and aerobic training performed in the same session (~ 60 min), three times a week, for 12 weeks. All assessments were performed pre and post-intervention. Metabolomics analyses were conducted using nuclear magnetic resonance spectroscopy (1H NMR) in a 600 MHz spectrometer. There was a decrease in body weight (BW), body mass index (BMI), waist circumference (WC), % body fat (%BF), fasting glucose, insulin levels, and insulin resistance (IR), by HOMA-IR, in the TG. An increase in fat-free mass (FFM) was also observed in the CG. The metabolic changes were given mainly by changes in the levels of metabolites 2-oxoisocaproate (↓TG), 3-hydroxyisobutyrate (↑CG and ↓TG), glucose (↓TG), glutamine (↓CG and ↑TG) and pyruvate (↓TG). These findings demonstrate the positive effects of CT program without dietary intervention on metabolomic profile, body composition, biochemical markers, and glucose metabolism in overweight and obese adolescents.

Regulation of Folliculogenesis by Growth Factors in Piglet Ovary Exposed Prenatally to β-Hydroxy-β-Methylbutyrate (HMB)

Β-hydroxy-β-methylbutyrate (HMB) is one of the leucine metabolites with protein anabolic effects which makes it very popular among athletes. Previously, it was shown that HMB administered during the prenatal period reduced the pool of primordial follicles and increased the proportion of developing follicles in newborn piglets. This work is a further step to understand these morphological alterations. Therefore, the aim of this study was to examine the effect of prenatal HMB treatment on the expression of the Kit ligand, BMP-4, bFGF, and the IGF-1/IGF-1R system which are the main growth factors controlling follicular development. Excised ovaries from 12 newborn piglets, originated from the control (n=6) and HMB-treated (n=6) sows were used for immunohistochemical and western-blot analysis. The tested proteins were localized within egg nests and ovarian follicles. Furthermore, the western-blot assay indicated higher BMP-4, Kit ligand, and IGF-1R expression, while the level of bFGF and IGF-1 proteins decreased after HMB dietary treatment. These findings show that HMB included into sow diet can modulate the expression of growth factors and thereby alter ovarian morphology in offspring. Therefore, this study opens a discussion about the benefits and risks of the diet supplemented with HMB and its potential application in medicine and animal husbandry, and further research is necessary in this area.

The addition of β-Hydroxy β-Methylbutyrate (HMB) to creatine monohydrate supplementation does not improve anthropometric and performance maintenance across a collegiate rugby season

BACKGROUND

Muscular damage sustained while playing rugby may hinder performance across a season. β-Hydroxy β-Methylbutyrate (HMB) may help attenuate muscle damage and maintain lean mass and performance. This study sought to determine the effect of combining HMB with creatine monohydrate supplementation on measures of stress and muscle damage, body composition, strength and sprinting kinetics throughout a rugby season.

METHODS

This double-blind, cross-over investigation recruited 16 male collegiate rugby players to provide resting blood samples and complete assessments of body composition, strength and sprinting performance prior to their fall season (PREFALL). After testing, the athletes were matched for fat-free mass and assigned to consume one of two supplementation regimens for 6 weeks: 5 g HMB + 5 g creatine per day (HMB-Cr: 20.9 ± 1.1 years; 177 ± 2 cm; 88.4 ± 4.9 kg) or 5 g creatine + 5 g placebo per day (Cr: 21.4 ± 2.1 years; 179 ± 2 cm; 88.3 ± 4.9 kg). After 6 weeks (POSTFALL), PREFALL testing was repeated in 13 of the original 16 athletes before a 10-wk wash-out period. Athletes who returned for the spring season (n = 8) repeated all fall-season procedures and testing prior to (PRESPRING) and following (POSTSPRING) their 6-wk spring season, except they were assigned to the opposite supplementation regimen.

RESULTS

Linear mixed models with repeated measures revealed group x time interactions (p <  0.05) for observed for several measures but did not consistently and positively favor one group. During the fall season, knee extensor peak torque was reduced by 40.7 ± 28.1 Nm (p = 0.035) for HMB-Cr but remained consistent for Cr, and no group differences or changes were noted in the spring. In the spring, greater knee flexor rate of torque development (~ 149 Nm·sec- 1, p = 0.003) and impulse (~ 4.5 Nm·sec, p = 0.022) were observed in Cr at PRESPRING but not at POSTSPRING. Although significant interactions were found for cortisol concentrations, vastus lateralis pennation angle, and sprinting force, post-hoc analysis only revealed differences between fall and spring seasons. No other differences were observed.

CONCLUSIONS

The combination of HMB and creatine monohydrate supplementation does not provide a greater ergogenic benefit compared to creatine monohydrate supplementation alone. Body composition, strength, and sprinting ability did not change across the season with creatine monohydrate supplementation.

Effects of the Combination of β-Hydroxy-β-Methyl Butyrate and R(+) Lipoic Acid in a Cellular Model of Sarcopenia

: Sarcopenia is a clinical problem associated with several pathological and non-pathological conditions. The aim of the present research is the evaluation of the pharmacological profile of the leucine metabolite β-hydroxy-β-methyl butyrate (HMB) associated with the natural R(+) stereoisomer of lipoic acid (R(+)LA) in a cellular model of muscle wasting. The C2C12 cell line is used as myoblasts or is differentiated in myotubes, sarcopenia is induced by dexamethasone (DEX). A Bonferroni significant difference procedure is used for a post hoc comparison. DEX toxicity (0.01-300 µM concentration range) is evaluated in myoblasts to measure cell viability and caspase 3 activation after 24 h and 48 h; cell incubation with 1 µM DEX for 48 h is chosen as optimal treatment for decreasing cell viability and increasing caspase 3 activity. R(+)LA or HMB significantly prevents DEX-induced cell mortality; the efficacy is improved when 100 µM R(+)LA is combined with 1 mM HMB. Regarding myoblasts, this combination significantly reduces DEX-evoked O2- production and protein oxidative damage. During the early phase of myotube formation, the mixture preserves the number of myogenin-positive cells, whereas it completely prevents the DEX-dependent damage in a later phase of myotube differentiation (7 days), as evaluated by cell diameter and percentage of multinucleated cells. R(+)LA in association with HMB is suggested for sarcopenia therapy.

Utilization of Hydroxyl-Methyl Butyrate, Leucine, Glutamine and Arginine Supplementation in Nutritional Management of Sarcopenia-Implications and Clinical Considerations for Type 2 Diabetes Mellitus Risk Modulation

While onset characteristics may vary, sarcopenia gradually develops over time as a result of the aging process, leading to muscle loss, disturbance of the muscle to fat ratio, and a variety of negative symptoms undermining the wellbeing, quality of life, and lifespan in the aging population globally. There is evidence that sarcopenia may be a cause and consequence of type 2 diabetes mellitus (T2DM) in the aging population. The importance of nutritional management in the prevention and/or deceleration of sarcopenia is critical, with the main focus placed on the amount and quality of protein intake. Significant efforts are being made towards the development of medical nutrition therapies involving certain amino acids and amino compounds, as well as their combinations, for the improvement in muscle strength, muscle function and protein synthesis. This may reduce hospitalization times and hasten the recovery of patients with sarcopenia. The administration of protocols with varying dose and frequencies, as well as their efficacy, is being investigated. In the work herein, we present and evaluate data derived from human trials regarding the utilization of hydroxyl-methyl butyrate (HMB), L-leucine (Leu), L-glutamine (Gln) and L-arginine (Arg) supplementation for optimal management of sarcopenia in geriatric patients, a topic of significant clinical nutrition interest which may have important implications in T2DM status.

Combined protein and calcium β-hydroxy-β-methylbutyrate induced gains in leg fat free mass: a double-blinded, placebo-controlled study

Background

The leucine metabolite β-hydroxy-β-methylbutyrate (HMB) is widely used as an ergogenic supplement to increase resistance-training induced gains in fat free mass (FFM) and strength in healthy adults. Recent studies have questioned the effectiveness of HMB, particularly when a high protein diet is habitually consumed. To investigate the additive resistance-training induced effects of HMB and protein in untrained individuals, we conducted a randomized double-blind, placebo-controlled study that compared the effects of combined protein and HMB supplementation to protein supplementation alone on FFM and muscle strength after 12-week resistance training.

Methods

Sixteen healthy men (22 ± 2 yrs) performed a periodized resistance-training program for twelve weeks (four sessions per week). The program comprised two mesocycles, characterized by a linear periodization and non-linear periodization, respectively, and separated by a 1-week tapering period. All participants received 60 g of whey protein on training days and 30 g of whey protein (WP) on non-training days. Participants were randomly assigned to additionally receive 3 g of calcium HMB (WP + HMB) or a placebo (WP + PLA). Body composition and physical fitness were tested before and after the 12-week training program. Whole-body and arm and leg fat free mass (FFM) were assessed by bioimpedance spectroscopy; upper arm and leg fat free cross sectional areas were also quantified using magnetic resonance imaging (MRI); upper and lower body strength were measured by One-repetition maximum (1-RM) bench press and leg press.

Results

Whole-body and segmental FFM increased in both groups (P <  0.001). However, gains in leg FFM were higher in WP + HMB vs. WP + PLA (arm FFM: + 6.1% vs. + 9.2%, P = 0.2; leg FFM: + 14.2% vs. + 7.0%, P <  0.01). No change in fat mass was observed (P = 0.59). 1-RM increased in both groups (P <  0.001).

Conclusions

Combined protein and HMB supplementation resulted in segmental, but not whole-body increases in FFM compared to protein supplementation alone. These findings could explain some of the controversial effects of HMB reported in previous studies and have practical implications for maximizing training-induced gains in FFM and clinical conditions associated with skeletal muscle deconditioning such as aging, sedentary lifestyles, bed rest and spaceflight.

Net Absorption and Metabolism of β-Hydroxy- β-Methyl Butyrate during Late Gestation in a Pig Model

The leucine metabolite, β-hydroxy-β-methyl butyrate (HMB), is widely used in human nutrition and animal production as a nutritional supplement. Although the HMB usage during late gestation has been demonstrated to have a positive effect on fetal development, knowledge on net absorption and metabolism of HMB and impact of HMB on branched chain amino acids (BCAAs) metabolism is lacking. To address this, we conducted a study using pigs during the perinatal period as a model organism. Eight-second parity sows were fitted with indwelling catheters in the femoral artery and in the portal, hepatic, femoral, and mesenteric veins. Eight hourly sets of blood samples were taken starting 30 min before the morning meal on day –10 and day –3 relative to parturition. Four control (CON) sows were fed a standard lactation diet from day –15 and throughout the experiment, and 4 HMB sows were fed the control diet supplemented with 15 mg Ca(HMB)₂/kg body weight mixed in one third of the morning meal from day –10 until parturition. Blood gases, plasma metabolites, milk compositions, and apparent total tract digestibility of nutrients were measured. Arterial plasma concentrations of HMB (p < 0.001), Cys (p < 0.001), and Lys (p < 0.10) were increased in HMB supplemented sows, while arterial plasma triglycerides concentration was decreased (p < 0.05). The net portal recovery of Ala and Asp were increased in HMB sows (p < 0.05). Sows fed HMB had increased hepatic vein flow and net hepatic fluxes of Met, Asn, and Gln (p < 0.05). In contrast, the femoral extraction rates of Ala and Ser were decreased by dietary HMB supplementation (p < 0.05). Dietary HMB treatment and sampling time relative to feeding had an interaction on arterial concentrations, net portal fluxes, and femoral extraction rates of BCAAs. The net portal recovery of HMB was 88%, while 14% of supplemented HMB was excreted through urine and 4% through feces. Moreover, the gastrointestinal tract metabolized 8% while the liver metabolized 12%. Finally, 26% of the daily intake of HMB was secreted via colostrum at the day of farrowing. This study demonstrated that dietary HMB supplementation increased net uptake of amino acids and increased fatty acid oxidation through improving blood flow and insulin sensitivity during the late gestation. Most importantly, oral HMB administration could maintain a stable postprandial absorption and altered metabolism in BCAAs. Net portal flux of HMB at 5.5 to 6.5 h after feeding approached zero, indicating that HMB ideally should be administrated two or three times, daily.

Recovery after volleyball: a narrative review

Volleyball is a popular sport, but there has been little research to date investigating the recovery process. Volleyball involves short bouts of high intensity exertion, often with limited time to rest between matches. This literature review highlights the specific methods used to recover after playing volleyball and evaluates their effectiveness. Recovery strategies have been shown to increase performance and prevent injury. Specific techniques identified include nutritional strategies, proper sleep, mental and psychological techniques, cold water immersion, and laser therapy. Some, such as nutrition and sleep, have been definitively shown to benefit volleyball players, while others, such as cold water immersion and laser therapy, have shown promise but require further research to determine their overall effect. Other areas of future research include evaluating the effectiveness of combined recovery techniques as well as determining which are best for rapid recovery.

Effect of in ovo feeding of β-hydroxy-β-methylbutyrate on hatchability, muscle growth and performance in prenatal and posthatch broilers

BACKGROUND

β-Hydroxy-β-methylbutyrate (HMB) is the metabolite of leucine that plays an important role in muscle protein metabolism. The objective of the present study was to determine the effects of in ovo feeding (IOF) of HMB at 7 days of incubation (DOI) via air cell or 18 DOI via amnion on hatchability, muscle growth and performance in prenatal and posthatch broilers.

RESULTS

IOF of HMB via air cell at 7 DOI increased hatchability by 4.34% compared with the control (89.67% versus 85.33%). Birds in IOF groups exhibited higher body weight, average daily body weight gain and pectoral muscle percentage. Furthermore, IOF of HMB significantly increased the level of plasma growth hormone, insulin and insulin-like growth factor-1. Chicks hatched from IOF treatment had larger diameters of muscle fiber and higher mitotic activity of satellite cells at early posthatch age. IOF of HMB activated satellite cells by upregulation of mRNA expression of myogenic transcription factors, myogenic differentiation one (MyoD) and myogenin. Chicks hatched from air cell injection group had higher pectoral muscle percentage at 5 d posthatch and greater satellite cell mitotic activity at 7 d posthatch than counterparts from amnion injection group.

CONCLUSIONS

IOF of HMB via amnion at 18 DOI or especially via air cell at 7 DOI could be used as an effective approach to enhance hatchability, productive performance and breast muscle yield in broilers. © 2019 Society of Chemical Industry.

Effect of Ten Weeks of Creatine Monohydrate Plus HMB Supplementation on Athletic Performance Tests in Elite Male Endurance Athletes

Creatine monohydrate (CrM) and β-hydroxy β-methylbutyrate (HMB) are common ergogenic aids in the field of sports and are frequently used in an isolated way. However, there are a few studies that have investigated the effect of combining both supplements on different variables related to performance, with controversial results. Therefore, the main purpose of this study was to determine the efficacy and the degree of potentiation of 10 weeks of CrM plus HMB supplementation on sports performance, which was measured by an incremental test to exhaustion in elite male traditional rowers. In this placebo-controlled, double-blind trial, 10-week study, participants (n = 28) were randomized to a placebo group (PLG; n = 7), CrM group (0.04 g/kg/day of CrM; n = 7), HMB group (3 g/day of HMB; n = 7) and CrM-HMB group (0.04 g/kg/day of CrM plus 3 g/day of HMB; n = 7). Before and after 10 weeks of different treatments, an incremental test was performed on a rowing ergometer to calculate the power that each rower obtained at the anaerobic threshold (WAT), and at 4 mmol (W4) and 8 mmol (W8) of blood lactate concentration. There were no significant differences in WAT and W4 among groups or in body composition. However, it was observed that the aerobic power achieved at W8 was significantly higher in the CrM-HMB group than in the PLG, CrM and HMB groups (p < 0.001; η2p = 0.766). Likewise, a synergistic effect of combined supplementation was found for the sum of the two supplements separately at WAT (CrM-HMBG = 403.19% vs. CrMG+HMBG = 337.52%), W4 (CrM-HMBG = 2736.17% vs. CrMG+HMBG = 1705.32%) and W8 (CrM-HMBG = 1293.4% vs. CrMG+HMBG = 877.56%). In summary, CrM plus HMB supplementation over 10 weeks showed a synergistic effect on aerobic power (measured as WAT, W4, and W8) during an incremental test but had no influence muscle mass.

Suppression of protein degradation by leucine requires its conversion to β-hydroxy-β-methyl butyrate in C2C12 myotubes

The aims of this study were to investigate whether the inhibitory effect of Leucine (Leu) on starvation-induced protein degradation was mediated by its metabolite β-hydroxy-β-methyl butyrate (HMB), and to explore the mechanisms involved. The results showed that the beneficial effects of Leu on protein degradation and the oxygen consumption rate (OCR) of cells were observed at low levels (0.5 mM) rather than at high levels (10 mM). However, these effects were inferior to those of HMB. Moreover, HMB was able to increase/decrease the proportion of MyHC I/MyHC IIb protein expression, respectively. In these KICD-transfected cells, Leu was approximately as effective as HMB in inhibiting protein degradation and increasing the OCR as well as MyHC I protein expression of cells, and these effects of Leu were reverted to a normal state by mesotrione, a specific suppressor of KICD. In conclusion, HMB seems to be an active metabolite of Leu to suppress muscle protein degradation in a starvation model, and the mechanisms may be associated with improved mitochondrial oxidative capacity in muscle cells.

Effects of a blend of green tea and curcuma extract supplementation on lipopolysaccharide-induced inflammation in horses and ponies

Background

In horses and ponies numerous medical conditions are known to be linked with inflammation in different tissues, especially in the liver. Besides affecting other metabolic pathways such as the expression of certain interleukins (IL), inflammation is associated with stress of the endoplasmic reticulum (ER). In particular, ER stress leads to adaptive stress response and can be measured by several markers of inflammatory and stress signalling pathways, like nuclear factor κB (NF-kB).

Objectives

To investigate lipopolysaccharide (LPS)-induced inflammatory reactions and their modulation in horses and ponies by feeding a polyphenol-rich supplement consisting of green tea and curcuma.

Methods

In a cross-over study, 11 animals were allocated to either a placebo or a supplement group and supplemented with 10 g of a blend of green tea and curcuma extract (GCE) or a placebo (calcium carbonate) once daily. After 21 days of supplementation, all animals underwent a LPS challenge to induce moderate systemic inflammation. Blood samples and liver biopsies were taken at standardized time points: 24 hours before and 12 hours after LPS challenge. Inflammatory blood parameters such as serum amyloid A (SAA), haptoglobin and retinol binding protein 4 (RBP4) were measured in serum. Hepatic mRNA levels of selected markers of inflammation such as haptoglobin, tumor necrosis factor α (TNF-α), IL-1β, IL-6, cluster of differentiation 68 (CD68), fibroblast growth factor 21 (FGF-21), NF-κB, activating transcription factor 4 (ATF4) were quantified by RT-qPCR. In addition, liver biopsies were examined histologically for inflammatory alterations.

Results

Blood markers of acute inflammatory response increased after LPS challenge. In the liver, the proinflammatory cytokine IL-1β showed significantly lower mRNA levels after LPS challenge in the supplemented group (P = 0.04) compared to the placebo group. Levels of the hepatic CD68 mRNA increased significantly in the placebo group (P = 0.04). There were no significant differences between supplemented and placebo groups concerning other markers of inflammation and markers of ER stress within the liver. The number of hepatic macrophages were not different after LPS challenge in both feeding groups.

Conclusion

LPS was able to induce inflammation but seemed less suitable to induce ER stress in the horses and ponies. The polyphenol-rich supplement showed some potential to reduce inflammatory responses. Nevertheless, the supplementation did not exert an overall anti-inflammatory effect in horses and ponies.

Effect of the Combination of Creatine Monohydrate Plus HMB Supplementation on Sports Performance, Body Composition, Markers of Muscle Damage and Hormone Status: A Systematic Review

Although there are many studies showing the isolated effect of creatine monohydrate (CrM) and β-hydroxy β-methylbutyrate (HMB), it is not clear what effect they have when they are combined. The main purpose of this systematic review was to determine the efficacy of mixing CrM plus HMB in comparison with their isolated effects on sports performance, body composition, exercise induced markers of muscle damage, and anabolic-catabolic hormones. This systematic review was carried out in accordance with PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement guidelines and the PICOS model, for the definition of the inclusion criteria. Studies were found by searching PubMed/MEDLINE, Web of Science (WOS), and Scopus electronic databases from inception to July 3rd 2019. Methodological quality and risk of bias were assessed by two authors independently, and disagreements were resolved by third-party evaluation, in accordance with the Cochrane Collaboration Guidelines samples. The literature was examined regarding the effects of the combination of CrM plus HMB on sport performance using several outcome variables (athletic performance, body composition, markers of muscle damage, and hormone status). This systematic review included six articles that investigated the effects of CrM plus HMB on sport performance (two on strength performance, showing improvements in one of them; three on anaerobic performance, presenting enhancements in two of them; and one on aerobic performance, not presenting improvements), body composition (three on body mass, showing improvements in one of them; two on fat free mass, presenting increases in one of them; and two on fat mass, showing decreases in one of them) and markers of muscle damage and hormone status (four on markers of muscle damage and one on anabolic-catabolic hormones, not showing benefits in any of them). In summary, the combination of 3–10 g/day of CrM plus 3 g/day of HMB for 1–6 weeks could produce potential positive effects on sport performance (strength and anaerobic performance) and for 4 weeks on body composition (increasing fat free mass and decreasing fat mass). However, this combination seems to not show positive effects relating to markers of exercise-induced muscle damage and anabolic-catabolic hormones.

The Effect of 12 Weeks of β-Hydroxy-β-Methyl-Butyrate Supplementation after Liver Transplantation: A Pilot Randomized Controlled Study

Sarcopenia is a frequent complication in liver transplant (LT) recipients. β-hydroxy-β-methyl-butyrate (HMB) has the potential to increase muscle-performance and tropism. Our study aims at evaluating the effect on muscle mass and functioning, and the safety of 12 weeks of HMB supplementation in patients after LT. This is a pilot, randomized study. Male patients undergoing LT were randomly assigned to the HMB or control group. A diet interview, anthropometry and body composition by dual energy X-ray absorptiometry (DEXA) were performed at enrollment (T0), after 12 weeks (T1) and after 12 months (T12). Twenty-two liver transplant male patients were enrolled in the study: 12 in the HMB group and 10 as the control group. At enrollment, demographic, clinical and nutritional data were similar. According to the appendicular skeletal muscle index, sarcopenia was present in 50% of patients. The appendix skeletal muscle mass index (ASMI) showed a significant increase at T1 and T12 in HMB patients, but not in controls. The mid-arm muscle-circumference and hand grip strength also increased at T1 and T12 versus T0 only in the HMB group. No side effects were reported in either group. The study showed a positive effect of HMB in the recovery of muscle mass and strength after LT. HMB supplement in patients after LT was safe and well tolerated.

Efficacy of Nutritional Interventions as Stand-Alone or Synergistic Treatments with Exercise for the Management of Sarcopenia

Sarcopenia is an age-related and accelerated process characterized by a progressive loss of muscle mass and strength/function. It is a multifactorial process associated with several adverse outcomes including falls, frailty, functional decline, hospitalization, and mortality. Hence, sarcopenia represents a major public health problem and has become the focus of intense research. Unfortunately, no pharmacological treatments are yet available to prevent or treat this age-related condition. At present, the only strategies for the management of sarcopenia are mainly based on nutritional and physical exercise interventions. The purpose of this review is, thus, to provide an overview on the role of proteins and other key nutrients, alone or in combination with physical exercise, on muscle parameters.

Mechanism of Action and the Effect of Beta-Hydroxy-Beta-Methylbutyrate (HMB) Supplementation on Different Types of Physical Performance - A Systematic Review

Beta-hydroxy-beta-methylbutyrate (HMB) has been used extensively as a dietary supplement for athletes and physically active people. HMB is a leucine metabolite, which is one of three branched chain amino acids. HMB plays multiple roles in the human body of which most important ones include protein metabolism, insulin activity and skeletal muscle hypertrophy. The ergogenic effects of HMB supplementation are related to the enhancement of sarcolemma integrity, inhibition of protein degradation (ubiquitin pathway), decreased cell apoptosis, increased protein synthesis (mTOR pathway), stimulation of the growth hormone/insulin-like growth factor-1 (GH/IGF-1) axis and enhancement of muscle stem cells proliferation and differentiation. HMB supplementation has been carried out with various groups of athletes. In endurance and martial arts athletes, HMB supplementation revealed positive effects on specific aerobic capacity variables. Positive results were also disclosed in resistance trained athletes, where changes in strength, body fat and muscle mass as well as anaerobic performance and power output were observed. The purpose of this review was to present the main mechanisms of HMB action, especially related to muscle protein synthesis and degradation, and ergogenic effects on different types of sports and physical activities.

Effect of Nutritional Support Containing Arginine, Glutamine and β-hydroxy-β-methylbutyrate on the Protein Balance in Patients with Major Burns

Objective

To evaluate the effect of a supplementary nutritional product containing arginine, glutamine and β-hydroxy-β-methylbutyrate (HMB) on the nutritional parameters of patients with major burns.

Methods

In a total of 40 patients with major burns treated in the Burns Unit, standard nutritional support was administered to 20 patients, and the study product was added to the standard nutritional support of the remaining 20 patients. The biochemical laboratory test results and burn severity were recorded on the first day of treatment and on Days 14 and 28. The 40 patients were divided as the study and the control group, and their results were compared.

Results

An increase in the albumin, prealbumin and total protein values in the group administered with the study product was found to be statistically significant compared to the control group (p=0.021, p=0.02, p<0.001, respectively). The decreases in haemoglobin and C-reactive protein (CRP) were at the levels expected in burn trauma.

Conclusion

The results obtained in this study demonstrated that the addition of arginine, glutamine and HMB to the nutrition of patients with burns had a positive effect on the protein balance.

Effects of β-hydroxy-β-methylbutyrate (HMB) supplementation in addition to multicomponent exercise in adults older than 70 years living in nursing homes, a cluster randomized placebo-controlled trial: the HEAL study protocol

Background

Evidence supports the fact that multicomponent exercise and HMB supplementation are, separately, effective in improving older adult’s health and palliate functional metabolic diseases in older people. However, the true effect of HMB supplementation combined with a tailored exercise program in frail older adults is still unknown. Thus, the aim of the HEAL (HMB + Exercise = Adults Living longer) study is to assess the effects of the combination of a daily multicomponent exercise and resistance training (VIVIFRAIL program) intervention in addition to HMB supplementation on older adults’ health.

Methods/design

A 24-week cluster randomized, double-blind, placebo-controlled study will be conducted on 104 adults ≥70 years. Nursing homes will be randomized to either of four groups: Ex-HMB (exercise intervention with HMB), Ex-Plac (exercise intervention with placebo), NoEx-HMB (no exercise intervention with HMB), and Controls (No exercise and no HMB). Intervention groups which include exercise will complete the individualized multicomponent (strength, balance and cardiovascular exercises) training program VIVIFRAIL. Intervention groups which include HMB supplementation will receive a 3 g/daily dose of free acid HMB in powder form. The primary outcome measure is the functional capacity. Secondary outcome measures are muscle strength and power, frailty and fall risk, body composition, biochemical analyses and cardiometabolic risk factor, disability and comorbidity, cognitive function and depression.

Discussion

The findings of the HEAL study will help professionals from public health systems to identify cost-effective and innovative actions to improve older people’s health and quality of life, and endorse exercise practice in older adults and people living in nursing homes.

Trial registration

NCT03827499; Date of registration: 01/02/2019.

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.

β-Hydroxy-β-methylbutyrate Suppresses NF-ĸB Activation and IL-6 Production in TE-1 Cancer Cells

BACKGROUND/AIM

Stress reactions, especially those related to surgery, cause poor convalescence of cancer patients. β-Hydroxyβ-methylbutyrate (HMB) is known to regulate excessive inflammation in the body. The objective of this work was to investigate the capacity of HMB to suppress activation of nuclear factor-kappa B (NF-ĸB) and production of interleukin-6 (IL-6) in a human esophageal squamous cell carcinoma cell line (TE-1).

MATERIALS AND METHODS

Cell proliferation was measured using the water-soluble tetrazolium-1 method, while tumor necrosis factor alpha (TNFα)-induced IL-6 production was measured using an enzyme-linked immunosorbent assay (ELISA) assay. Nuclear translocation of NF-ĸB was detected by immunofluorescence staining.

RESULTS

HMB did not affect cell proliferation. However, HMB suppressed the TNFα-induced increase in IL-6 production in TE-1 cells by inhibiting NF-ĸB activation.

CONCLUSION

HMB did not influence TE-1 cell proliferation, but inhibited activation of NF-ĸB and IL-6 production. This result may be useful for improving excessive stress reactions during and after surgery.

Sarcopenia Associated with Chronic Obstructive Pulmonary Disease

Sarcopenia is frequently associated with chronic diseases such as chronic obstructive pulmonary disease (COPD) and cancer. COPD, which is characterized by an irreversible airflow limitation, exacerbates respiratory distress as the disease progresses. The prevalence of sarcopenia in stable COPD was reported to be 15% to 25% in previous foreign studies and 25% in a Korean study. As the amount of activity decreases, muscle mass decreases and eventually oxygen cannot be used effectively, resulting in a vicious cycle of deterioration of exercise capacity. Deconditioning due to decreased activity is a major cause of limb muscle dysfunction in patients with COPD. In these patients, the factors that decrease muscle strength and endurance include chronic inflammation, oxidative stress, inactivity, hypoxemia, hormone abnormality, deficits of nutrients such as protein and vitamin D, and the use of systemic corticosteroid. Therefore, treatment and management should either inhibit this process or should be directed toward supplementing the deficiency, such as with exercise, nutritional support, and medications and supplements. The relationship between sarcopenia and COPD is increasingly being reported, with some overlap in clinical features and treatments. We are fascinated to be able to diagnose 2 diseases through similar physical performance tests and to improve both diseases using the same treatment such as exercise. Therefore, this review summarizes the clinical relevance and integrative management of the 2 diseases.

β-Hydroxy-β-methylbutyrate and its impact on skeletal muscle mass and physical function in clinical practice: a systematic review and meta-analysis

BACKGROUND

Loss of skeletal muscle mass and muscle weakness are common in a variety of clinical conditions with both wasting and weakness associated with an impairment of physical function. β-Hydroxy-β-methylbutyrate (HMB) is a nutrition supplement that has been shown to favorably influence muscle protein turnover and thus potentially plays a role in ameliorating skeletal muscle wasting and weakness.

OBJECTIVES

The aim of this study was to investigate the efficacy of HMB alone, or supplements containing HMB, on skeletal muscle mass and physical function in a variety of clinical conditions characterized by loss of skeletal muscle mass and weakness.

METHODS

A systematic review and meta-analysis of randomized controlled trials reporting outcomes of muscle mass, strength, and physical function was performed. Two reviewers independently performed screening, data extraction, and risk-of-bias assessment. Outcome data were synthesized through meta-analysis with the use of a random-effects model and data presented as standardized mean differences (SMDs).

RESULTS

Fifteen randomized controlled trials were included, involving 2137 patients. Meta-analysis revealed some evidence to support the effect of HMB alone, or supplements containing HMB, on increasing skeletal muscle mass (SMD = 0.25; 95% CI: -0.00, 0.50; z = 1.93; P = 0.05; I2 = 58%) and strong evidence to support improving muscle strength (SMD = 0.31; 95% CI: 0.12, 0.50; z = 3.25; P = 0.001; I2 = 0%). Effect sizes were small. No effect on bodyweight (SMD = 0.16; 95% CI: -0.08, 0.41; z = 1.34; P = 0.18; I2 = 67%) or any other outcome was found. No study was considered to have low risk of bias in all categories.

CONCLUSION

HMB, and supplements containing HMB, increased muscle mass and strength in a variety of clinical conditions, although the effect size was small. Given the bias associated with many of the included studies, further high-quality studies should be undertaken to enable interpretation and translation into clinical practice. The trial was registered on PROSPERO as CRD42017058517.