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1.
J Int Soc Sports Nutr ; 17(1): 16, 2020 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-32164702

RESUMO

BACKGROUND: The leucine metabolite ß-hydroxy-ß-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.


Assuntos
Cálcio/administração & dosagem , Músculo Esquelético/fisiologia , Substâncias para Melhoria do Desempenho/administração & dosagem , Treinamento de Resistência , Valeratos/administração & dosagem , Proteínas do Soro do Leite/administração & dosagem , Composição Corporal , Suplementos Nutricionais , Método Duplo-Cego , Humanos , Masculino , Coxa da Perna/fisiologia , Adulto Jovem
2.
Pol J Vet Sci ; 22(4): 725-733, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31867925

RESUMO

The objective of this study was to determine the applicability of the Migratest® kit for evaluating the chemotactic activity of peripheral blood neutrophils in goats. The experiment was performed on 14 goat kids aged 30±2 days, divided into two groups of 7 animals each: C - control group, and E - experimental group, supplemented with ß-hydroxy-ß-methylbutyrate (HMB), a typical immunostimulant which influences the phagocytic activity of peripheral neutrophils. The feed administered to experimental goat kids was supplemented with HMB at 40 mg/kg BW, whereas control goat kids were administered standard farm-made feed without supplementation. Blood was sampled from the jugular vein immediately before the experiment (day 0) and on experimental days 15, 30 and 60 to determine the chemotactic activity of peripheral blood neutrophils in goats. The results of the study indicate that the Migratest® kit can be used to evaluate the influence of immunomodulators on the chemotactic activity of peripheral blood neutrophils in goats. The results of the assay are most effectively presented by calculating the chemotactic index which accounts for the chemotaxis or migration of neutrophils in the presence or absence of a chemotactic factor, respectively, and the percentage of granulocytes that migrate towards fMLP. The results of both presentation methods appear to be identical.


Assuntos
Cabras/sangue , Neutrófilos/efeitos dos fármacos , Kit de Reagentes para Diagnóstico/veterinária , Valeratos/administração & dosagem , Ração Animal/análise , Animais , Dieta/veterinária , Suplementos Nutricionais , Neutrófilos/fisiologia
3.
Nutrients ; 11(9)2019 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-31546969

RESUMO

Sarcopenia is a frequent complication in liver transplant (LT) recipients. ß-hydroxy-ß-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.


Assuntos
Transplante de Fígado , Valeratos/farmacologia , Idoso , Suplementos Nutricionais , Humanos , Pessoa de Meia-Idade , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/patologia , Projetos Piloto , Cuidados Pós-Operatórios , Sarcopenia/prevenção & controle , Valeratos/administração & dosagem
4.
Nutrients ; 11(9)2019 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-31484462

RESUMO

Both regular exercise training and beta-hydroxy-beta-methylbutyrate (HMB) supplementation are shown as effective treatments to delay or reverse frailty and reduce cognitive impairment in older people. However, there is very little evidence on the true benefits of combining both strategies. The aim of this meta-analysis was to quantify the effects of exercise in addition to HMB supplementation, on physical and cognitive health in older adults. Data from 10 randomized controlled trials (RCTs) investigating the effect of HMB supplementation and physical function in adults aged 50 years or older were analyzed, involving 384 participants. Results showed that HMB supplementation in addition to physical exercise has no or fairly low impact in improving body composition, muscle strength, or physical performance in adults aged 50 to 80 years, compared to exercise alone. There is a gap of knowledge on the beneficial effects of HMB combined with exercise to preserve cognitive functions in aging and age-related neurodegenerative diseases. Future RCTs are needed to refine treatment choices combining HMB and exercises for older people in particular populations, ages, and health status. Specifically, interventions in older adults aged 80 years or older, with cognitive impairment, frailty, or limited mobility are required.


Assuntos
Envelhecimento , Suplementos Nutricionais , Exercício Físico/fisiologia , Valeratos/farmacologia , Humanos , Valeratos/administração & dosagem
5.
Food Funct ; 10(8): 5152-5165, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31373594

RESUMO

The aim of this study was to investigate the effects of dietary ß-hydroxy-ß-methylbutyrate (HMB) on lipopolysaccharide (LPS)-induced muscle atrophy and to investigate the mechanisms involved. Sixty pigs (21 ± 2 days old, 5.86 ± 0.18 kg body weight) were used in a 2 × 3 factorial design and the main factors included diet (0, 0.60%, or 1.20% HMB) and immunological challenge (LPS or saline). After 15 d of treatment with LPS and/or HMB, growth performance, blood parameters, and muscle protein degradation rate were measured. The results showed that in LPS-injected pigs, 0.60% HMB supplementation increased the average daily gain and average daily feed intake and decreased the feed : gain ratio (P < 0.05), with a concurrent increase of lean percentage. Moreover, 0.60% HMB supplementation decreased the serum concentrations of blood urea nitrogen, IL-1ß, and TNF-α and the rate of protein degradation as well as cell apoptosis in selected muscles (P < 0.05). In addition, dietary HMB supplementation (0.60%) regulated the expression of genes involved in mitochondrial biogenesis and increased the phosphorylation of Akt and Forkhead Box O3a (FoxO3a) in selected muscles, accompanied by decreased protein expression of muscle RING finger 1 and muscle atrophy F-box. These results indicate that HMB may exert protective effects against LPS-induced muscle atrophy by normalizing the Akt/FoxO3a axis that regulates ubiquitin proteolysis and by improving mitochondrial biogenesis.


Assuntos
Proteína Forkhead Box O3/metabolismo , Mitocôndrias/efeitos dos fármacos , Proteínas Musculares/metabolismo , Atrofia Muscular/veterinária , Proteínas Proto-Oncogênicas c-akt/metabolismo , Doenças dos Suínos/prevenção & controle , Valeratos/administração & dosagem , Ração Animal/análise , Animais , Feminino , Proteína Forkhead Box O3/genética , Interleucina-1beta/genética , Interleucina-1beta/metabolismo , Lipopolissacarídeos/efeitos adversos , Masculino , Mitocôndrias/metabolismo , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/metabolismo , Atrofia Muscular/induzido quimicamente , Atrofia Muscular/metabolismo , Atrofia Muscular/prevenção & controle , Biogênese de Organelas , Proteólise/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/genética , Transdução de Sinais/efeitos dos fármacos , Suínos , Doenças dos Suínos/induzido quimicamente , Doenças dos Suínos/genética , Doenças dos Suínos/metabolismo
6.
Biosci Biotechnol Biochem ; 83(10): 1851-1857, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31159662

RESUMO

Several food constituents augment exercise-induced muscle strength improvement; however, the detailed mechanism underlying these combined effects is unknown because of the lack of a cultured cell model for evaluating the contraction-induced muscle protein synthesis level. Here, we aimed to establish a new in vitro muscle contraction model for analyzing the activation of mammalian target of rapamycin complex 1 (mTORC1) signaling. We adopted the tetanic electric stimulation of 50 V at 100 Hz for 10 min in L6.C11 myotubes. Akt, ERK1/2, and p70S6K phosphorylation increased significantly after electrical pulse stimulation (EPS), compared to untreated cells. Next, we used this model to analyze mTORC1 signaling in combination with exercise and beta-hydroxy-beta-methylbutyrate (HMB), an l-leucine metabolite. p70S6K phosphorylation increased significantly in the EPS+HMB group compared to that in the EPS-alone group. These findings show that our model could be used to analyze mTORC1 signaling and that HMB enhances muscle contraction-activated mTORC1 signaling.


Assuntos
Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Músculo Esquelético/efeitos dos fármacos , Transdução de Sinais , Valeratos/administração & dosagem , Animais , Linhagem Celular , Estimulação Elétrica , Técnicas In Vitro , L-Lactato Desidrogenase/metabolismo , Contração Muscular , Músculo Esquelético/citologia , Músculo Esquelético/enzimologia , Músculo Esquelético/fisiologia , Ratos
7.
Spectrochim Acta A Mol Biomol Spectrosc ; 222: 117271, 2019 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-31226619

RESUMO

Structural changes in the enamel surface subjected to induced demineralization and assessment of the influence of prenatal administration of ß-hydroxy ß-methylbutyrate (HMB) on enamel resistance were investigated. The examination was conducted on five sets of teeth from one-day-old spiny mice (Acomys cahirinus), one from the control and four from the experimental groups. Surface structure, molecular arrangement and crystalline organization of offspring's enamel both before and after etching were studied. Obtained results revealed that the physical and molecular arrangements of enamel were altered after the prenatal supplementation, and significantly affected its final structure and resistance against acid action. The enamel of incisors from the offspring which mothers were supplemented with HMB in a high dose (0.2 g/kgbw) and in the late period of gestation (26th-39th day) showed the highest endurance against acid treatment demonstrating only vestigial changes in their surface structure after acid action. Comparing to the remaining experimental groups, it was characterized by a reduced roughness and fractal dimension, significantly lower degree of demineralization and simultaneous lack of notable differences in the Raman spectra before and after acid etching. The results suggest that an increased enamel resiliency was the effect of a relatively high degree of mineralization and higher organization of the surface.


Assuntos
Esmalte Dentário/efeitos dos fármacos , Valeratos/farmacologia , Ácidos/química , Animais , Animais Recém-Nascidos , Esmalte Dentário/embriologia , Esmalte Dentário/ultraestrutura , Suplementos Nutricionais , Feminino , Camundongos , Modelos Moleculares , Gravidez , Cuidado Pré-Natal , Propriedades de Superfície/efeitos dos fármacos , Valeratos/administração & dosagem
8.
J Sports Sci ; 37(17): 2037-2044, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31079555

RESUMO

Leucine metabolites may reduce training-induced inflammation; however, there is scant evidence for this assertion. We conducted a double-blind randomized controlled pragmatic trial where 40 male participants were allocated into 4 groups: α-hydroxyisocaproic acid group ([α-HICA], n = 10, Fat-free mass [FFM] = 62.0 ± 7.1 kg), ß-hydroxy-ß-methylbutyrate free acid group ([HMB-FA], n = 11, FFM = 62.7 ± 10.5 kg), calcium ß-hydroxy-ß-methylbutyrate group ([HMB-Ca], n = 9, FFM = 65.6 ± 10.1 kg) or placebo group ([PLA]; n = 10, FFM = 64.2 ± 5.7 kg). An 8-week whole-body resistance training routine (3 training sessions per week) was employed to induce gains in skeletal-muscle thickness. Skeletal muscle thickness (MT), one repetition maximum (1RM), interleukin-6 (IL-6), high-sensitivity C-reactive protein (hsCRP) and tumour necrosis factor alpha (TNF-α) were assessed at baseline and at the end of weeks 4 and 8. Time-dependent increases were detected from baseline to week 8 for MT (vastus lateralis: p = 0.009; rectus femoris: p = 0.018), 1RM (back squat: α-HICA, 18.5% ± 18.9%; HMB-FA, 23.2% ± 16%; HMB-Ca, 10.5% ± 13.8%; PLA, 19.7% ± 9% and bench press: α-HICA, 13.8% ± 19.1%; HMB-FA, 15.5% ± 9.3%; HMB-Ca, 10% ± 10.4%; PLA, 14.4 ± 11.3%, both p < 0.001), IL-6, hsCRP (both p < 0.001) and TNF-α (p = 0.045). No differences were found between groups at any time point. No leucine metabolite attenuated inflammation during training. Additionally, backwards elimination regressions showed that no circulating inflammatory marker consistently shared variance with the change in any outcome. Using leucine metabolites to modulate inflammation cannot be recommended from the results obtained herein. Furthermore, increases in inflammatory markers, from training, do not correlate with any outcome variable and are likely the result of training adaptations.


Assuntos
Caproatos/administração & dosagem , Inflamação/sangue , Leucina/metabolismo , Treinamento de Resistência , Fenômenos Fisiológicos da Nutrição Esportiva , Valeratos/administração & dosagem , Adulto , Biomarcadores/sangue , Composição Corporal , Proteína C-Reativa/análise , Cálcio , Suplementos Nutricionais , Método Duplo-Cego , Humanos , Interleucina-6/sangue , Masculino , Força Muscular , Músculo Esquelético/crescimento & desenvolvimento , Músculo Esquelético/fisiologia , Fator de Necrose Tumoral alfa/sangue , Adulto Jovem
9.
Am J Clin Nutr ; 109(4): 1119-1132, 2019 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-30982854

RESUMO

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. ß-Hydroxy-ß-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.


Assuntos
Debilidade Muscular/tratamento farmacológico , Músculo Esquelético/efeitos dos fármacos , Valeratos/administração & dosagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Suplementos Nutricionais/análise , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Força Muscular/efeitos dos fármacos , Debilidade Muscular/fisiopatologia , Músculo Esquelético/crescimento & desenvolvimento , Músculo Esquelético/fisiopatologia , Ensaios Clínicos Controlados Aleatórios como Assunto , Adulto Jovem
10.
Int J Sport Nutr Exerc Metab ; 29(5): 505-511, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-30859862

RESUMO

This study evaluated the effects of ß-hydroxy-ß-methylbutyrate free acid (HMB-FA) and calcium salt (HMB-Ca) on strength, hypertrophy, and markers of muscle damage. In this randomized, double-blind, placebo-controlled study, 44 resistance-trained men (age: 26 ± 4 years; body mass: 84.9 ± 12.0 kg) consuming ≥1.7 g·kg-1·day-1 of protein received HMB-FA (3 g/day; n = 14), HMB-Ca (3 g/day; n = 15), or placebo (PL; cornstarch, 3 g/day; n = 15) for 12 weeks, while performing a periodized resistance training program. Before and after intervention, lean body mass (measured with dual X-ray absorptiometry), maximal dynamic strength (one-repetition maximum), knee extension maximal isometric strength (maximal voluntary isometric contraction [MVIC]), cross-sectional area (measured with ultrasound), and muscle soreness were assessed. MVIC was also measured 48 hr after the first and the last training sessions. All groups increased lean body mass (main time effect: p < .0001; HMB-FA: 1.8 ± 1.8 kg; HMB-Ca: 0.8 ± 1.4 kg; PL: 0.9 ± 1.4 kg), cross-sectional area (main time effect: p < .0001; HMB-FA: 6.6 ± 3.8%; HMB-Ca: 4.7 ± 4.4%; PL: 6.9 ± 3.8%), one-repetition maximum bench press (main time effect: p < .0001; HMB-FA: 14.8 ± 8.4 kg; HMB-Ca: 11.8 ± 7.4 kg; PL: 11.2 ± 6.6 kg), MVIC (main time effect: p < .0001; HMB-FA: 34.4 ± 39.3%; HMB-Ca: 32.3 ± 27.4%; PL: 17.7 ± 20.9%) after the intervention, but no differences between groups were shown. HMB-FA group showed greater leg press strength after the intervention than HMB-Ca and PL groups (Group × Time interaction: p < .05; HMB-FA: 47.7 ± 31.2 kg; HMB-Ca: 43.8 ± 31.7 kg; PL: 30.2 ± 20.9 kg). MVIC measured 48 hr after the first and the last sessions showed no attenuation of force decline with supplementation. Muscle soreness following the first and last sessions was not different between groups. The authors concluded that neither HMB-Ca nor HMB-FA improved hypertrophy or reduced muscle damage in resistance-trained men undergoing resistance training ingesting optimal amounts of protein. HMB-FA but not HMB-Ca resulted in a statistically significant yet minor improvement on leg press one-repetition maximum.


Assuntos
Cálcio/administração & dosagem , Força Muscular , Músculo Esquelético/crescimento & desenvolvimento , Treinamento de Resistência , Fenômenos Fisiológicos da Nutrição Esportiva , Valeratos/administração & dosagem , Adulto , Composição Corporal , Método Duplo-Cego , Humanos , Contração Isométrica , Masculino , Mialgia , Adulto Jovem
11.
J Anim Physiol Anim Nutr (Berl) ; 103(2): 626-643, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30659706

RESUMO

It has been demonstrated in animal studies that prenatal administration of ß-hydroxy-ß-methylbutyrate (HMB, metabolite of leucine) influences general growth and mechanical endurance of long bones in newborn offspring in sex-dependent manner. The present experiment was conducted to evaluate the effect of HMB treatment of pregnant sows on bone development in offspring at weaning. From 70th day until the 90th day of gestation, sows received either a basal diet (n = 12) or the same diet supplemented with HMB (n = 12) at the dose of 0.2 g/kg of body weight/day. Femora obtained from six males and females in each group weaned at the age of 35 days were examined. Maternal HMB treatment significantly enhanced body weight and changed bone morphology increasing femur mechanical strength in both sexes. Maternal HMB supplementation also elevated bone micro- and macroelement concentrations and enhanced content of proteoglycans in articular cartilage. Based on the obtained results, it can be concluded that maternal HMB supplementation in the mid-gestation period significantly accelerated bone development in both sexes by upregulation of a multifactorial system including leptin and osteoprotegerin. However, the sex (irrespective of the HMB treatment) was the factor which influenced the collagen structure in cartilages and trabecular bone, as demonstrated both by the Picrosirius red staining and performed analysis of thermal stability of collagenous tissues. The structural differences in collagen between males and females were presumably related to a different collagen maturity. No studies conducted so far provided a detailed morphological analysis of bone, articular cartilage, growth plate and the activities of the somatotropic and pituitary-gonadal axes, as well as leptin/osteoprotegerin system in weaned offspring prenatally treated with HMB. This study showed also the relationship between the maternal HMB treatment and bone osteometric and mechanical traits, hormones, and growth and bone turnover markers such as leptin, osteoprotegerin and insulin-like growth factor-1.


Assuntos
Dieta/veterinária , Suplementos Nutricionais , Cartilagem Hialina/efeitos dos fármacos , Leptina/metabolismo , Suínos , Valeratos/farmacologia , Ração Animal/análise , Fenômenos Fisiológicos da Nutrição Animal , Animais , Fenômenos Biomecânicos , Desenvolvimento Ósseo/efeitos dos fármacos , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Cartilagem Hialina/crescimento & desenvolvimento , Gravidez , Fenômenos Fisiológicos da Nutrição Pré-Natal , Distribuição Aleatória , Valeratos/administração & dosagem
12.
Curr Opin Clin Nutr Metab Care ; 22(1): 37-43, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30489401

RESUMO

PURPOSE OF REVIEW: Given the role of leucine as a major regulator of muscle protein turnover, the consumption of protein sources enhanced with this essential amino acid, or its metabolite beta-hydroxy-beta-methylbutyrate (HMB), is assumed to give the greatest benefit in terms of maintenance of muscle mass and function during aging. The aim of this review is to discuss recent literature about HMB metabolism, its pharmacokinetics compared with the metabolite leucine, effectiveness of HMB to improve outcomes in older adults, and novel approaches for HMB use. RECENT FINDINGS: Overall, this review article highlights the potential relationship between HMB dietary supplementation and parameters related to maintenance of muscle mass and strength in older people. However, there are limitations in the studies conducted so far, including low number of participants per study group, heterogeneity of study designs, methodologies, and outcomes. The combination of HMB with other amino acids or supplements limits the ability to determine the direct impact of HMB alone. SUMMARY: It is proposed that HMB may be utilized to protect or rebuild muscle mass in older people with reduced lean body mass.


Assuntos
Leucina/administração & dosagem , Leucina/metabolismo , Sarcopenia/metabolismo , Valeratos/administração & dosagem , Valeratos/metabolismo , Idoso , Suplementos Nutricionais , Idoso Fragilizado , Humanos , Proteínas Musculares/deficiência , Proteínas Musculares/metabolismo , Músculo Esquelético/metabolismo , Desempenho Físico Funcional , Sarcopenia/dietoterapia
13.
Med Sci Sports Exerc ; 51(1): 56-64, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30102677

RESUMO

Leucine metabolites, α-hydroxyisocaproic acid (α-HICA) and ß-hydroxy-ß-methylbutyrate (calcium, HMB-Ca and free acid, HMB-FA), have been proposed to augment resistance training-induced changes in body composition and performance. PURPOSE: We aimed to conduct a double-blind randomized controlled pragmatic trial to evaluate the effects of off-the-shelf leucine metabolite supplements of α-HICA, HMB-FA, and HMB-Ca on resistance training-induced changes in muscle thickness and performance. METHODS: Forty men were randomly assigned to receive α-HICA (n = 10, fat-free mass [FFM] = 62.0 ± 7.1 kg), HMB-FA (n = 11, FFM = 62.7 ± 10.5 kg), HMB-Ca (n = 9, FFM = 65.6 ± 10.1 kg), or placebo (PLA; n = 10, FFM = 64.2 ± 5.7 kg). The training program consisted of whole body thrice weekly resistance training for 8 wk (seven exercises per session, three to four sets per session, at 70%-80% one repetition maximum). Skeletal muscle thickness by ultrasound, performance measures, and blood measures (creatine kinase, insulin-like growth factor 1, growth hormone, cortisol, and total testosterone) were evaluated at baseline and at the end of weeks 4 and 8. RESULTS: Time-dependent changes were observed for muscle thickness (P < 0.001), one repetition maximum bench press and squat (P < 0.001), Wingate peak power (P = 0.02), countermovement jump height (P = 0.03), power (P = 0.006), creatine kinase, insulin-like growth factor-1, growth hormone, and cortisol (all P < 0.001). No significant between-group or time-group interactions were observed. CONCLUSIONS: No leucine metabolite resulted in any ergogenic effects on any outcome variable. Supplementation with leucine metabolites-α-HICA, HMB-FA, or HMB-Ca-is not a supplementation strategy that improves muscle growth and strength development in young adult men.


Assuntos
Caproatos/administração & dosagem , Suplementos Nutricionais , Força Muscular/fisiologia , Músculo Esquelético/anatomia & histologia , Músculo Esquelético/fisiologia , Substâncias para Melhoria do Desempenho/administração & dosagem , Treinamento de Resistência , Valeratos/administração & dosagem , Adolescente , Adulto , Desempenho Atlético/fisiologia , Biomarcadores/sangue , Composição Corporal , Creatina Quinase/sangue , Método Duplo-Cego , Hormônio do Crescimento Humano/sangue , Humanos , Hidrocortisona/sangue , Fator de Crescimento Insulin-Like I/metabolismo , Masculino , Pessoa de Meia-Idade , Adulto Jovem
14.
Med Sci Sports Exerc ; 51(1): 65-74, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30113522

RESUMO

Ingestion of proteins with high leucine content during resistance training (RT) can augment hypertrophy. Some data suggest that a leucine metabolite, ß-hydroxy, ß-methylbutyrate (HMB), is substantially more anabolically efficacious than leucine. PURPOSE: We aimed to test whether supplementation with HMB versus leucine, added to whey protein, would result in differential muscle hypertrophy and strength gains in young men performing RT. METHODS: Twenty-six resistance-trained men (23 ± 2 yr) performed 12 wk of RT with three phases. Phase 1: 8 wk of periodized RT (three training sessions per week). Phase 2: 2 wk overreaching period (five sessions per week). Phase 3: 2 wk taper (three sessions per week). Participants were randomly assigned to twice daily ingestion of: whey protein (25 g) plus HMB (1.5 g) (whey+HMB; n = 13) or whey protein (25 g) plus leucine (1.5 g) (whey+leu; n = 13). Skeletal muscle biopsies were performed before and after RT. Measures of fat- and bone-free mass, vastus lateralis (VL) muscle thickness and muscle cross-sectional area (CSA) (both by ultrasound), muscle fiber CSA, and 1-repetition maximum (1-RM) strength tests were determined. RESULTS: We observed increases in fat- and bone-free mass, VL muscle thickness, muscle CSA and fiber type CSA and 1-RM strength with no differences between groups at any phase. We observed no differences between groups or time-group interactions in hormone concentrations at any phase of the RT program. CONCLUSIONS: ß-Hydroxy-ß-methylbutyrate added to whey did not result in greater increases in any measure of muscle mass, strength, or hormonal concentration compared to leucine added to whey. Our results show that HMB is no more effective in stimulating RT-induced hypertrophy and strength gains than leucine.


Assuntos
Suplementos Nutricionais , Leucina/administração & dosagem , Força Muscular/fisiologia , Músculo Esquelético/anatomia & histologia , Músculo Esquelético/fisiologia , Substâncias para Melhoria do Desempenho/administração & dosagem , Treinamento de Resistência , Valeratos/administração & dosagem , Adulto , Biópsia , Composição Corporal , Creatina Quinase/sangue , Método Duplo-Cego , Hormônio do Crescimento Humano/sangue , Humanos , Hidrocortisona/sangue , Fator de Crescimento Insulin-Like I/metabolismo , Masculino , Músculo Esquelético/diagnóstico por imagem , Testosterona/sangue , Ultrassonografia , Adulto Jovem
15.
Res Sports Med ; 27(2): 204-218, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30348016

RESUMO

ß-Hydroxy-ß-Methylbutyrate (HMB) is a metabolite of the branched-chain amino acid leucine and its ketoacid α-ketoisocaproate. HMB has been widely used as an ergogenic supplement to increase muscle strength, muscle hypertrophy and enhance recovery. The physiological mechanisms that underlie these benefits are related to HMB's ability to stimulate muscle protein synthesis and minimize muscle breakdown. Although evidence supporting the benefits of HMB supplementation is not conclusive, many of these studies have suffered from methodological flaws including different formulations, supplement duration and population studied. HMB in its free acid formulation is suggestive of having a greater potential for efficacy in both trained and untrained populations than its calcium-salt form. However, the evidence regarding HMB's role in limiting muscle degradation and increasing muscle protein synthesis has created an exciting interest in examining its efficacy among untrained individuals. Recent investigations examining intense training have demonstrated efficacy in maintaining muscle mass and attenuating the inflammatory response.


Assuntos
Desempenho Atlético/fisiologia , Músculo Esquelético/efeitos dos fármacos , Fenômenos Fisiológicos da Nutrição Esportiva/efeitos dos fármacos , Fenômenos Fisiológicos da Nutrição Esportiva/fisiologia , Valeratos/administração & dosagem , Aminoácidos Essenciais/administração & dosagem , Atletas , Composição Corporal/efeitos dos fármacos , Suplementos Nutricionais , Humanos , Leucina/administração & dosagem , Desenvolvimento Muscular/efeitos dos fármacos , Força Muscular/efeitos dos fármacos
16.
J Diet Suppl ; 16(5): 576-591, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-29969326

RESUMO

We aimed to evaluate effects of ß-hydroxy-ß-methylbutyrate, L-glutamine, and L-arginine (HMB/GLN/ARG) on radiation-induced acute intestinal toxicity. Forty rats were divided into four groups: group (G) 1 was defined as control group, and G2 was radiation therapy (RT) control group. G3 and G4 were HMB/GLN/ARG control and RT plus HMB/GLN/ARG groups, respectively. HMB/GLN/ARG started from day of RT and continued until the animals were sacrificed 10 days after RT. The extent of surface epithelium smoothing, villous atrophy, lamina propria inflammation, cryptitis, crypt distortion, regenerative atypia, vascular dilatation and congestion, and fibrosis were quantified on histological sections of intestinal mucosa. Statistical analyses were performed using the analysis of variance (ANOVA) test. There were significant differences between study groups regarding extent of surface epithelium smoothing, villous atrophy, lamina propria inflammation, cryptitis and crypt distortion, regenerative atypia, vascular dilatation and congestion, and fibrosis (p values were 0.019 for fibrosis, <.001 for the others). Pair-wise comparisons revealed significant differences regarding surface epithelium smoothing, villous atrophy, lamina propria inflammation, cryptitis, vascular dilatation, and congestion between G2 and G4 (p values were <.001, .033, <.001, .007, and <.001, respectively). Fibrosis score was significantly different only between G1 and G2 (p = .015). Immunohistochemical TGF-ß score of G2 was significantly higher than G1 and G3 (p values were .006 and .017, respectively). There was no difference between TGF-ß staining scores of G2 and G4. Concomitant use of HMB/GLN/ARG appears to ameliorate radiation-induced acute intestinal toxicity; however, this finding should be clarified with further studies.


Assuntos
Arginina/administração & dosagem , Glutamina/administração & dosagem , Enteropatias/tratamento farmacológico , Lesões Experimentais por Radiação/tratamento farmacológico , Valeratos/administração & dosagem , Animais , Suplementos Nutricionais , Feminino , Fibrose/patologia , Imuno-Histoquímica , Inflamação/patologia , Enteropatias/etiologia , Enteropatias/patologia , Mucosa Intestinal/química , Mucosa Intestinal/patologia , Mucosa Intestinal/efeitos da radiação , Lesões Experimentais por Radiação/etiologia , Ratos , Ratos Wistar , Fator de Crescimento Transformador beta/análise
17.
In Vivo ; 33(1): 155-161, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30587616

RESUMO

BACKGROUND/AIM: Sorafenib is standard treatment for advanced hepatocellular carcinoma (HCC). Hand-foot skin reaction (HFSR) is a notorious side-effect of this therapy. This study evaluated prophylactic benefits of an oral nutritional supplement (ONS) on sorafenib-associated HFSR in advanced HCC. PATIENTS AND METHODS: This was a prospective, single-center, open-label trial arm using combined ONS and sorafenib in patients with unresectable HCC from August 2014 to February 2018. Control patients received sorafenib without ONS from 2011 to 2014. From September 2014, prophylactic ONS containing ß-hydroxy-ß-methylbutyrate (HMB), L-arginine, and L-glutamine was given. Sorafenib dosage was 400 mg/day for both groups. RESULTS: Each group comprised 22 men and three women. Age, sex, Child-Pugh score, and clinical stage excluding IV-B did not significantly differ between the groups. HFSR occurred after 2 weeks: 15/25 patients in the control group (60%; HFSR grade 1: 6, grade 2: 7, grade 3: 2) vs. 8/25 in the ONS group (32%; HFSR grade 1: 4, grade 2: 4, grade 3: 0; p=0.047, Pearson's Chi-square test). CONCLUSION: Prophylactic HMB, L-arginine and L-glutamine supplementation effectively prevented sorafenib-associated HFSR in patients with advanced HCC.


Assuntos
Carcinoma Hepatocelular/tratamento farmacológico , Síndrome Mão-Pé/dietoterapia , Neoplasias Hepáticas/tratamento farmacológico , Sorafenibe/efeitos adversos , Idoso , Idoso de 80 Anos ou mais , Arginina/administração & dosagem , Carcinoma Hepatocelular/complicações , Carcinoma Hepatocelular/patologia , Feminino , Glutamina/administração & dosagem , Síndrome Mão-Pé/etiologia , Síndrome Mão-Pé/patologia , Síndrome Mão-Pé/prevenção & controle , Humanos , Neoplasias Hepáticas/complicações , Neoplasias Hepáticas/patologia , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Pele/efeitos dos fármacos , Pele/patologia , Valeratos/administração & dosagem
18.
Eur J Sport Sci ; 19(6): 802-810, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30588860

RESUMO

ß-hydroxy-ß-methylbutyrate (calcium: HMB-Ca and free acid: HMB-FA) and α-hydroxyisocaproic acid (α-HICA) are leucine metabolites that have been proposed to improve body composition and strength when combined with resistance exercise training (RET). In this double-blind randomized controlled pragmatic trial, we evaluated the effects of off-the-shelf supplements: α-HICA, HMB-FA and HMB-Ca, on RET-induced changes in body composition and performance. Forty men were blocked randomized to receive α-HICA (n = 10, fat-free mass [FFM] = 62.0 ± 7.1 kg), HMB-FA (n = 11, FFM = 62.7 ± 10.5 kg), HMB-Ca (n = 9, FFM = 65.6 ± 10.1 kg) or placebo (PLA; n = 10, FFM = 64.2 ± 5.7 kg). The training protocol consisted of a whole-body resistance training routine, thrice weekly for 8 weeks. Body composition was assessed by dual-energy x-ray absorptiometry (DXA) and total body water (TBW) by whole-body bioimpedance spectroscopy (BIS), both at baseline and at the end of weeks 4 and 8. Time-dependent changes were observed for increase in trunk FFM (p < 0.05). No statistically significant between-group or group-by-time interactions were observed. Supplementation with HMB (FA and Ca) or α-HICA failed to enhance body composition to a greater extent than placebo. We do not recommend these leucine metabolites for improving body composition changes with RET in young adult resistance trained men.


Assuntos
Composição Corporal , Caproatos/administração & dosagem , Suplementos Nutricionais , Treinamento de Resistência , Fenômenos Fisiológicos da Nutrição Esportiva , Valeratos/administração & dosagem , Absorciometria de Fóton , Adulto , Espectroscopia Dielétrica , Método Duplo-Cego , Humanos , Masculino , Adulto Jovem
19.
Food Funct ; 9(9): 4836-4846, 2018 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-30137075

RESUMO

BACKGROUND: The effects and roles of the leucine (Leu) metabolite ß-hydroxy-ß-methylbutyrate (HMB) in lipid metabolism in adipose tissues of pigs are still unknown. OBJECTIVES: This study was conducted to investigate the effects of excess Leu versus HMB on growth, carcass traits, and lipid metabolism in adipose tissues of growing pigs. METHODS AND RESULTS: Compared to control, the Leu/HMB group significantly increased/reduced weight of total fat mass, respectively, with a concurrent increase of serum adiponectin concentration (P < 0.05). Moreover, dietary HMB supplementation regulated the expression of genes involved in adipose tissue function, accompanied by increases/decreases in the phosphorylation of AMPKα/mTOR in perirenal adipose tissue, respectively (P < 0.05). Serum IL-15 concentration and the mRNA abundance of IL-15, PGC-1α, and NRF-1 were also increased in the HMB group (P < 0.05). CONCLUSIONS: HMB supplementation can regulate adipose tissue function including fatty acid oxidation, lipolysis, and adipokine secretion. These effects may be partly mediated by AMPKα-mTOR pathway and associated with mitochondrial biogenesis, the AMPK-PGC-1α axis, and myokines secreted by muscle tissues.


Assuntos
Tecido Adiposo Branco/metabolismo , Adiposidade , Dieta/veterinária , Metabolismo dos Lipídeos , Valeratos/administração & dosagem , Proteínas Quinases Ativadas por AMP/metabolismo , Adiponectina/sangue , Tecido Adiposo Branco/crescimento & desenvolvimento , Tecido Adiposo Branco/imunologia , Aminoácidos de Cadeia Ramificada/sangue , Animais , Biomarcadores/sangue , China , Cruzamentos Genéticos , Regulação da Expressão Gênica no Desenvolvimento , Cetoácidos/administração & dosagem , Lipólise , Fosforilação , Processamento de Proteína Pós-Traducional , Subunidades Proteicas/metabolismo , Distribuição Aleatória , Sus scrofa , Serina-Treonina Quinases TOR/metabolismo , Ganho de Peso
20.
J Anim Physiol Anim Nutr (Berl) ; 102(6): 1543-1552, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30027589

RESUMO

To investigate the effect of in ovo feeding (IOF) of beta-hydroxy beta-methylbutyrate (HMB), dextrin and post-hatching water and feed deprivation time on growth performance of broilers, 1,500 eggs were assigned into 15 experimental runs of Box-Behnken design, including three levels IOF of HMB (0%, 0.5% and 1%), dextrin (0%, 20% and 40%) and three levels of the first water and feed deprivation (6, 27 and 48 hr). After hatching, day-old chicks (seven males and seven females) from each replicate were then selected and randomly assigned to 60 floor pens for a 42-day feeding trial. The experimental data were fitted to the quadratic response surface models, and the goodness of fit of the models was expressed by the R2 value. The interaction between IOF of dextrin and timing of first feed deprivation had the largest effect on body weight of chicks at day 7 (BW7) and corrected European production efficiency factor (EPEF). In ovo feeding of dextrin reduced negative effects of delayed access to feed and water after hatch up to 48 hr on BW7, body weight of chicks at day 42, EPEF and corrected EPEF. The results of the current study suggested that the EPEF corrected by hatchability could provide the better understanding of IOF experimental findings. The ridge optimization analysis revealed that the optimal levels of HMB and dextrin inclusion in eggs and timing of first feed deprivation for maximum corrected EPEF were 0.37, 15.94% and 7.22 hr, respectively. These results demonstrate that the Box-Behnken statistical design and response surface models are effective to describe the relationship between IOF of nutrients and pre-placement holding time and predict the performance of broilers to achieve the optimal target.


Assuntos
Embrião de Galinha/efeitos dos fármacos , Galinhas/crescimento & desenvolvimento , Dextrinas/administração & dosagem , Valeratos/farmacologia , Animais , Feminino , Privação de Alimentos , Masculino , Distribuição Aleatória , Valeratos/administração & dosagem
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