Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 13 de 13
Filtrar
1.
BJU Int ; 134(1): 110-118, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38587276

RESUMO

OBJECTIVE: To report the protocol of a study evaluating the efficacy of transdermal oestradiol (E2) gel in reducing the adverse effects of androgen deprivation therapy (ADT), specifically on sexual function, and to assess the utility of E2 in combination with supervised exercise. STUDY DESIGN AND METHODS: The primary endpoint of this open-label Phase IIA randomized controlled trial is the efficacy of transdermal E2 gel. Secondary endpoints include: (i) the occurrence of ADT-induced adverse effects; (ii) the safety and tolerability of E2; (iii) the impact of E2 with or without exercise on physical, physiological, muscle, and systemic biomarkers; and (iv) quality of life. The trial will recruit high-risk PCa patients (n = 310) undergoing external beam radiation therapy with adjuvant subcutaneous ADT. Participants will be stratified and randomized in a 1:1 ratio to either the E2 + ADT arm or the ADT-only control arm. Additionally, a subset of patients (n = 120) will be randomized into a supervised exercise programme. RESULTS: The primary outcome is assessed according to the efficacy of E2 in mitigating the deterioration of Expanded Prostate Cancer Index Composite sexual function domain scores. Secondary outcomes are assessed according to the occurrence of ADT-induced adverse effects, safety and tolerability of E2, impact of E2 with or without exercise on physical performance, body composition, bone mineral density, muscle size, systematic biomarkers, and quality of life. CONCLUSION: The ESTRACISE study's innovative design can offer novel insights about the benefits of E2 gel, and the substudy can reinforce the benefits resistance training and deliver valuable new novel insights into the synergistic benefits of E2 gel and exercise, which are currently unknown. TRIAL REGISTRATION: The protocol has been registered in euclinicaltrials.eu (2023-504704-28-00) and in clinicaltrials.gov (NCT06271551).


Assuntos
Administração Cutânea , Antagonistas de Androgênios , Estradiol , Terapia por Exercício , Neoplasias da Próstata , Humanos , Masculino , Antagonistas de Androgênios/efeitos adversos , Antagonistas de Androgênios/uso terapêutico , Neoplasias da Próstata/tratamento farmacológico , Estradiol/administração & dosagem , Terapia por Exercício/métodos , Qualidade de Vida , Ensaios Clínicos Controlados Aleatórios como Assunto , Terapia Combinada , Ensaios Clínicos Fase II como Assunto
2.
Trials ; 23(1): 1026, 2022 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-36539791

RESUMO

BACKGROUND: Regular participation in resistance exercise is known to have broad-ranging health benefits and for this reason is prominent in the current physical activity guidelines. Recovery after such exercise is important for several populations across the age range and nutritional strategies to enhance recovery and modulate post-exercise physiological processes are widely studied, yet effective strategies remain elusive. Vitamin K2 supplementation has emerged as a potential candidate, and the aim of the current study, therefore, is to test the hypothesis that vitamin K2 supplementation can accelerate recovery, via modulation of the underlying physiological processes, following a bout of resistance exercise in young and older adults. METHODS: The current study is a two-arm randomised controlled trial which will be conducted in 80 (40 young (≤40 years) and 40 older (≥65 years)) adults to compare post-exercise recovery in those supplemented with vitamin K2 or placebo for a 12-week period. The primary outcome is muscle strength with secondary outcomes including pain-free range of motion, functional abilities, surface electromyography (sEMG) and markers of inflammation and oxidative stress. DISCUSSION: Ethical approval has been granted by the College of Medical Veterinary and Life Sciences Ethical Committee at the University of Glasgow (Project No 200190189) and recruitment is ongoing. Study findings will be disseminated through a presentation at scientific conferences and in scientific journals. TRIAL REGISTRATION: ClinicialTrials.gov NCT04676958. Prospectively registered on 21 December 2020.


Assuntos
Treinamento Resistido , Humanos , Idoso , Vitamina K 2/farmacologia , Exercício Físico , Força Muscular , Músculo Esquelético , Ensaios Clínicos Controlados Aleatórios como Assunto
3.
Aging Clin Exp Res ; 32(4): 605-616, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31183750

RESUMO

BACKGROUND: Adaptation to strength training in very old mobility-limited individuals is not fully characterized. Therefore, the aim of this study was to perform a thorough investigation of the adaptation to a lower body strength training regime in this population, with particular emphasis on the relationship between changes in selected variables. METHODS: Twenty-two mobility-limited older men and women (85 ± 6 years) were randomized to either a group performing 30 min of heavy-load strength training three times a week, with daily protein supplementation, for 10 weeks (ST), or a control group. End points were leg lean mass assessed by DXA, muscle thickness assessed by ultrasound, isometric and dynamic strength, rate of torque development, and functional capacity. RESULTS: Leg lean mass increased from baseline in ST (0.7 ± 0.3 kg), along with increased thickness of vastus lateralis (4.4 ± 3.2%), rectus femoris (6.7 ± 5.1%), and vastus intermedius (5.8 ± 5.9%). The hypertrophy was accompanied by improved knee extensor strength (20-23%) and functional performance (7-11%). In ST, neither the change in leg lean mass nor muscle thickness correlated with changes in muscle strength. However, a strong correlation was observed between the change in isometric strength and gait velocity (r = 0.70). CONCLUSIONS: The mismatch between gains in muscle size and strength suggests that muscle quality-related adaptations contributed to the increases in strength. The correlations observed between improvements in strength and function suggests that interventions eliciting large improvements in strength may also be superior in terms of functional gains in this population.


Assuntos
Suplementos Nutricionais , Força Muscular/fisiologia , Desempenho Físico Funcional , Proteínas/administração & dosagem , Treinamento Resistido/métodos , Idoso , Idoso de 80 Anos ou mais , Feminino , Fragilidade/prevenção & controle , Humanos , Masculino , Limitação da Mobilidade
4.
Med Sci Sports Exerc ; 51(1): 75-83, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30157103

RESUMO

BACKGROUND: A rapid digestibility and high leucine content are considered important for maximal stimulation of muscle protein synthesis. Consequently, with these properties, native whey may hold greater anabolic potential than milk, when supplemented in combination with strength training. Our aim was to compare the effects of supplementation with milk or native whey, during a 12-wk strength training period, on gains in muscle mass and strength in young adults. METHODS: In this double-blinded, randomized, controlled study a total of 40 untrained young men and women received two daily servings of either milk or native whey containing 20 g of protein, during a 12-wk strength training intervention. Muscle strength, lean mass, thigh muscle cross-sectional area, m. vastus lateralis thickness and muscle fiber cross-sectional area were assessed before and after the training period. In addition, the acute phosphorylation of the anabolic kinases p70S6K, 4E-BP1 and eEF-2 in response to a standardized workout and supplementation was investigated before and after the 12-wk training period. RESULTS: Muscle mass and strength increased, by all measures applied (5%-16%, P < 0.001), with no differences between groups (P > 0.25). p70S6K phosphorylation increased (~1000%, P < 0.02) 2 h after exercise in the untrained and trained state, but no differences in anabolic signaling were observed between supplements (P > 0.40). No correlation between these acute measures and changes in muscle mass or strength were observed. CONCLUSION: Supplementation with milk or native whey during a 12-wk strength training period did not differentially affect muscle mass and strength in young untrained individuals.


Assuntos
Suplementos Nutricionais , Proteínas do Leite/administração & dosagem , Força Muscular/fisiologia , Músculo Esquelético/anatomia & histologia , Músculo Esquelético/fisiologia , Substâncias para Melhoria do Desempenho/administração & dosagem , Treinamento Resistido , Proteínas do Soro do Leite/administração & dosagem , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Adulto , Aminoácidos/sangue , Animais , Glicemia/metabolismo , Proteínas de Ciclo Celular , Creatina Quinase/sangue , Método Duplo-Cego , Quinase do Fator 2 de Elongação/metabolismo , Feminino , Humanos , Insulina/sangue , Masculino , Proteínas Musculares/biossíntese , Músculo Esquelético/metabolismo , Fosfoproteínas/metabolismo , Fosforilação , Proteínas Quinases S6 Ribossômicas 70-kDa/metabolismo , Ureia/sangue , Adulto Jovem
5.
J Appl Physiol (1985) ; 125(2): 271-286, 2018 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-29698111

RESUMO

Strenuous exercise can result in skeletal muscle damage, leading to the systemic mobilization, activation, and intramuscular accumulation of blood leukocytes. Eicosanoid metabolites of arachidonic acid (ARA) are potent inflammatory mediators, but whether changes in dietary ARA intake influence exercise-induced inflammation is not known. This study investigated the effect of 4 wk of dietary supplementation with 1.5 g/day ARA ( n = 9, 24 ± 1.5 yr) or corn-soy oil placebo ( n = 10, 26 ± 1.3 yr) on systemic and intramuscular inflammatory responses to an acute bout of resistance exercise (8 sets each of leg press and extension at 80% one-repetition maximum) in previously trained men. Whole EDTA blood, serum, peripheral blood mononuclear cells (PMBCs), and skeletal muscle biopsies were collected before exercise, immediately postexercise, and at 2, 4, and 48 h of recovery. ARA supplementation resulted in higher exercise-stimulated serum creatine kinase activity [incremental area under the curve (iAUC) P = 0.046] and blood leukocyte counts (iAUC for total white cells, P < 0.001; neutrophils: P = 0.007; monocytes: P = 0.015). The exercise-induced fold change in peripheral blood mononuclear cell mRNA expression of interleukin-1ß ( IL1B), CD11b ( ITGAM), and neutrophil elastase ( ELANE), as well as muscle mRNA expression of the chemokines interleukin-8 ( CXCL8) and monocyte chemoattractant protein 1 ( CCL2) was also greater in the ARA group than placebo. Despite this, ARA supplementation did not influence the histological presence of leukocytes within muscle, perceived muscle soreness, or the extent and duration of muscle force loss. These data show that ARA supplementation transiently increased the inflammatory response to acute resistance exercise but did not impair recovery. NEW & NOTEWORTHY Daily arachidonic acid supplementation for 4 wk in trained men augmented the acute systemic and intramuscular inflammatory response to a subsequent bout of resistance exercise. Greater exercise-induced inflammatory responses in men receiving arachidonic acid supplementation were not accompanied by increased symptoms of exercise-induced muscle damage. Although increased dietary arachidonic acid intake does not appear to influence basal inflammation in humans, the acute inflammatory response to exercise stress is transiently increased following arachidonic acid supplementation.


Assuntos
Ácido Araquidônico/administração & dosagem , Exercício Físico/fisiologia , Inflamação/tratamento farmacológico , Treinamento Resistido/efeitos adversos , Adolescente , Adulto , Antígeno CD11b/metabolismo , Quimiocina CCL2/metabolismo , Creatina Quinase/metabolismo , Suplementos Nutricionais , Humanos , Inflamação/metabolismo , Interleucina-1beta/metabolismo , Interleucina-8/metabolismo , Elastase de Leucócito/metabolismo , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/metabolismo , Masculino , Força Muscular/efeitos dos fármacos , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/metabolismo , Mialgia/tratamento farmacológico , Mialgia/metabolismo , RNA Mensageiro/metabolismo , Adulto Jovem
6.
J Appl Physiol (1985) ; 124(4): 1080-1091, 2018 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-29389245

RESUMO

Arachidonic acid (ARA), a polyunsaturated ω-6 fatty acid, acts as precursor to a number of prostaglandins with potential roles in muscle anabolism. It was hypothesized that ARA supplementation might enhance the early anabolic response to resistance exercise (RE) by increasing muscle protein synthesis (MPS) via mammalian target of rapamycin (mTOR) pathway activation and/or the late anabolic response by modulating ribosome biogenesis and satellite cell expansion. Nineteen men with ≥1 yr of resistance-training experience were randomized to consume either 1.5 g daily ARA or a corn-soy-oil placebo in a double-blind manner for 4 wk. Participants then undertook fasted RE (8 sets each of leg press and extension at 80% 1-repetition maximum), with vastus lateralis biopsies obtained before exercise, immediately postexercise, and at 2, 4, and 48 h of recovery. MPS (measured via stable isotope infusion) was not different between groups ( P = 0.212) over the 4-h recovery period. mTOR pathway members p70 S6 kinase and S6 ribosomal protein were phosphorylated postexercise ( P < 0.05), with no difference between groups. 45S preribosomal RNA increased 48 h after exercise only in ARA ( P = 0.012). Neural cell adhesion molecule-positive satellite cells per fiber increased 48 h after exercise ( P = 0.013), with no difference between groups ( P = 0.331). Prior ARA supplementation did not alter the acute anabolic response to RE in previously resistance-trained men; however, at 48 h of recovery, ribosome biogenesis was stimulated only in the ARA group. The findings do not support a mechanistic link between ARA and short-term anabolism, but ARA supplementation in conjunction with resistance training may stimulate increases in translational capacity. NEW & NOTEWORTHY Four weeks of daily arachidonic acid supplementation in trained men did not alter their acute muscle protein synthetic or anabolic signaling response to resistance exercise. However, 48 h after exercise, men supplemented with arachidonic acid showed greater ribosome biogenesis and a trend toward greater change in satellite cell content. Chronic arachidonic acid supplementation does not appear to regulate the acute anabolic response to resistance exercise but may augment muscle adaptation in the following days of recovery.


Assuntos
Ácido Araquidônico/administração & dosagem , Proteínas Musculares/biossíntese , Músculo Esquelético/efeitos dos fármacos , Treinamento Resistido , Adulto , Suplementos Nutricionais , Humanos , Sistema de Sinalização das MAP Quinases , Masculino , Ribossomos/metabolismo , Células Satélites de Músculo Esquelético , Adulto Jovem
7.
J Int Soc Sports Nutr ; 14: 43, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29200982

RESUMO

BACKGROUND: Protein intake is essential to maximally stimulate muscle protein synthesis, and the amino acid leucine seems to possess a superior effect on muscle protein synthesis compared to other amino acids. Native whey has higher leucine content and thus a potentially greater anabolic effect on muscle than regular whey (WPC-80). This study compared the acute anabolic effects of ingesting 2 × 20 g of native whey protein, WPC-80 or milk protein after a resistance exercise session. METHODS: A total of 24 young resistance trained men and women took part in this double blind, randomized, partial crossover, controlled study. Participants received either WPC-80 and native whey (n = 10), in a crossover design, or milk (n = 12). Supplements were ingested immediately (20 g) and two hours after (20 g) a bout of heavy-load lower body resistance exercise. Blood samples and muscle biopsies were collected to measure plasma concentrations of amino acids by gas-chromatography mass spectrometry, muscle phosphorylation of p70S6K, 4E-BP1 and eEF-2 by immunoblotting, and mixed muscle protein synthesis by use of [2H5]phenylalanine-infusion, gas-chromatography mass spectrometry and isotope-ratio mass spectrometry. Being the main comparison, differences between native whey and WPC-80 were analysed by a one-way ANOVA and comparisons between the whey supplements and milk were analysed by a two-way ANOVA. RESULTS: Native whey increased blood leucine concentrations more than WPC-80 and milk (P < 0.05). Native whey ingestion induced a greater phosphorylation of p70S6K than milk 180 min after exercise (P = 0.03). Muscle protein synthesis rates increased 1-3 h hours after exercise with WPC-80 (0.119%), and 1-5 h after exercise with native whey (0.112%). Muscle protein synthesis rates were higher 1-5 h after exercise with native whey than with milk (0.112% vs. 0.064, P = 0.023). CONCLUSIONS: Despite higher-magnitude increases in blood leucine concentrations with native whey, it was not superior to WPC-80 concerning effect on muscle protein synthesis and phosphorylation of p70S6K during a 5-h post-exercise period. Native whey increased phosphorylation of p70S6K and muscle protein synthesis rates to a greater extent than milk during the 5-h post exercise period. TRIAL REGISTRATION: This study was retrospectively registered at clinicaltrials.gov as NCT02968888.


Assuntos
Suplementos Nutricionais , Leucina/análise , Músculo Esquelético/efeitos dos fármacos , Treinamento Resistido , Fenômenos Fisiológicos da Nutrição Esportiva , Proteínas do Soro do Leite/química , Proteínas do Soro do Leite/farmacologia , Estudos Cross-Over , Método Duplo-Cego , Feminino , Voluntários Saudáveis , Humanos , Leucina/farmacologia , Masculino , Proteínas Musculares/biossíntese , Músculo Esquelético/fisiologia , Biossíntese de Proteínas/efeitos dos fármacos , Adulto Jovem
8.
Eur J Appl Physiol ; 117(6): 1073-1084, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28382551

RESUMO

PURPOSE: Resistance training is beneficial for maintaining bone mass. We aimed to investigate the skeletal effects of high doses of antioxidants [vitamin C + E (α-tocopherol)] supplementation during 12-week supervised strength training in healthy, elderly men METHODS: Design: double-blinded randomized placebo-controlled study. Participants followed a supervised, undulating periodic exercise program with weekly adjusted load: 3 sessions/week and 3-15 repetitions maximum (RM) sets/exercise. The control group (CG, n = 17, 67 ± 5 years) received placebo and the antioxidant group (AO, n = 16, 70 ± 7 years) 1000 mg vitamin C + 235 mg vitamin E, daily. Areal bone mineral density (aBMD) at whole body, lumbar spine (L1-L4), total hip, and femoral neck were measured by dual energy X-ray absorptiometry and muscle strength by 1RM. Serum analyses of bone-related factors and adipokines were performed. RESULTS: In the CG, total hip aBMD increased by 1.0% (CI: 0.3-1.7) versus pretest and lumbar spine aBMD increased by 0.9% (CI: -0.2 to 2.0) compared to the AO. In the CG, there was an increase in serum concentrations of insulin-like growth factor 1 [+27.3% (CI: -0.3 to 54.9)] and leptin [+31.2% (CI: 9.8-52.6)) versus pretest, and a decrease in sclerostin [-9.9% (CI: 4.4-15.3)] versus pretest and versus AO. Serum bone formation markers P1NP and osteocalcin increased in both groups, while the bone resorption marker CTX-1 remained unchanged. CONCLUSION: High doses of antioxidant supplementations may constrain the favorable skeletal benefits of 12 weeks of resistance exercise in healthy elderly men.


Assuntos
Ácido Ascórbico/farmacologia , Densidade Óssea , Treinamento Resistido , Vitamina E/farmacologia , Vitaminas/farmacologia , Idoso , Ácido Ascórbico/administração & dosagem , Desenvolvimento Ósseo , Osso e Ossos/efeitos dos fármacos , Método Duplo-Cego , Humanos , Masculino , Pessoa de Meia-Idade , Vitamina E/administração & dosagem , Vitaminas/administração & dosagem
9.
Physiol Rep ; 2(10)2014 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-25293598

RESUMO

Reactive oxygen and nitrogen species are important signal molecules for adaptations to training. Due to the antioxidant properties of vitamin C and E, supplementation has been shown to blunt adaptations to endurance training. In this study, we investigated the effects of vitamin C and E supplementation and endurance training on adaptations in endogenous antioxidants and heat shock proteins (HSP). Thirty seven males and females were randomly assigned to receive Vitamin C and E (C + E; C: 1000 mg, E: 235 mg daily) or placebo (PLA), and underwent endurance training for 11 weeks. After 5 weeks, a subgroup conducted a high intensity interval session to investigate acute stress responses. Muscle and blood samples were obtained to investigate changes in proteins and mRNA related to the antioxidant and HSP system. The acute response to the interval session revealed no effects of C + E supplementation on NFκB activation. However, higher stress responses to exercise in C + E group was indicated by larger translocation of HSPs and a more pronounced gene expression compared to PLA. Eleven weeks of endurance training decreased muscle GPx1, HSP27 and αB-crystallin, while mnSOD, HSP70 and GSH remained unchanged, with no influence of supplementation. Plasma GSH increased in both groups, while uric acid decreased in the C + E group only. Our results showed that C + E did not affect long-term training adaptations in the antioxidant- and HSP systems. However, the greater stress responses to exercise in the C + E group might indicate that long-term adaptations occurs through different mechanisms in the two groups.

10.
Artigo em Inglês | MEDLINE | ID: mdl-25075311

RESUMO

BACKGROUND: Antioxidant supplementation has recently been demonstrated to be a double-edged sword, because small to moderate doses of exogenous antioxidants are essential or beneficial, while high doses may have adverse effects. The adverse effects can be manifested in attenuated effects of exercise and training, as the antioxidants may shut down some redox-sensitive signaling in the exercised muscle fibers. However, conditions such as age may potentially modulate the need for antioxidant intake. Therefore, this paper describes experiments for testing the hypothesis that high dosages of vitamin C (1000 mg/day) and E (235 mg/day) have negative effects on adaptation to resistance exercise and training in young volunteers, but positive effects in older men. METHODS/DESIGN: We recruited a total of 73 volunteers. The participants were randomly assigned to receiving either vitamin C and E supplementation or a placebo. The study design was double-blinded, and the participants followed an intensive training program for 10-12 weeks. Tests and measurements aimed at assessing changes in physical performance (maximal strength) and physiological characteristics (muscle mass), as well as biochemical and cellular systems and structures (e.g., cell signaling and morphology). DISCUSSION: Dietary supplements, such as vitamin C and E, are used by many people, especially athletes. The users often believe that high dosages of supplements improve health (resistance to illness and disease) and physical performance. These assumptions are, however, generally not supported in the scientific literature. On the contrary, some studies have indicated that high dosages of antioxidant supplements have negative effects on exercise-induced adaptation processes. Since this issue concerns many people and few randomized controlled trials have been conducted in humans, further studies are highly warranted. TRIAL REGISTRATION: ACTRN12614000065695.

11.
J Physiol ; 592(8): 1887-901, 2014 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-24492839

RESUMO

In this double-blind, randomised, controlled trial, we investigated the effects of vitamin C and E supplementation on endurance training adaptations in humans. Fifty-four young men and women were randomly allocated to receive either 1000 mg of vitamin C and 235 mg of vitamin E or a placebo daily for 11 weeks. During supplementation, the participants completed an endurance training programme consisting of three to four sessions per week (primarily of running), divided into high-intensity interval sessions [4-6 × 4-6 min; >90% of maximal heart rate (HRmax)] and steady state continuous sessions (30-60 min; 70-90% of HRmax). Maximal oxygen uptake (VO2 max ), submaximal running and a 20 m shuttle run test were assessed and blood samples and muscle biopsies were collected, before and after the intervention. Participants in the vitamin C and E group increased their VO2 max (mean ± s.d.: 8 ± 5%) and performance in the 20 m shuttle test (10 ± 11%) to the same degree as those in the placebo group (mean ± s.d.: 8 ± 5% and 14 ± 17%, respectively). However, the mitochondrial marker cytochrome c oxidase subunit IV (COX4) and cytosolic peroxisome proliferator-activated receptor-γ coactivator 1 α (PGC-1α) increased in the m. vastus lateralis in the placebo group by 59 ± 97% and 19 ± 51%, respectively, but not in the vitamin C and E group (COX4: -13 ± 54%; PGC-1α: -13 ± 29%; P ≤ 0.03, between groups). Furthermore, mRNA levels of CDC42 and mitogen-activated protein kinase 1 (MAPK1) in the trained muscle were lower in the vitamin C and E group than in the placebo group (P ≤ 0.05). Daily vitamin C and E supplementation attenuated increases in markers of mitochondrial biogenesis following endurance training. However, no clear interactions were detected for improvements in VO2 max and running performance. Consequently, vitamin C and E supplementation hampered cellular adaptations in the exercised muscles, and although this did not translate to the performance tests applied in this study, we advocate caution when considering antioxidant supplementation combined with endurance exercise.


Assuntos
Ácido Ascórbico/farmacologia , Exercício Físico , Consumo de Oxigênio/efeitos dos fármacos , Resistência Física/efeitos dos fármacos , Vitamina E/farmacologia , Vitaminas/farmacologia , Adaptação Fisiológica , Adulto , Ácido Ascórbico/administração & dosagem , Suplementos Nutricionais , Método Duplo-Cego , Complexo IV da Cadeia de Transporte de Elétrons/genética , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Feminino , Humanos , Masculino , Proteína Quinase 1 Ativada por Mitógeno/genética , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/metabolismo , Músculo Esquelético/fisiologia , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Vitamina E/administração & dosagem , Vitaminas/administração & dosagem , Proteína cdc42 de Ligação ao GTP/genética , Proteína cdc42 de Ligação ao GTP/metabolismo
12.
J Clin Endocrinol Metab ; 99(1): 194-202, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24248184

RESUMO

CONTEXT: The effect of vitamin D on muscle strength in adults is not established. OBJECTIVE: Our objective was to test whether vitamin D supplementation increases muscle strength and power compared with placebo. DESIGN: We conducted a randomized, double-blind, placebo-controlled trial. SETTING: The setting was immigrants' activity centers. PARTICIPANTS: Two hundred fifty-one healthy adult males and females aged 18-50 years with non-Western immigrant background performed the baseline test and 86% returned to the follow-up test. INTERVENTIONS: Sixteen weeks of daily supplementation with 25 µg (1000 IU) vitamin D3, 10 µg (400 IU) vitamin D3, or placebo. MAIN OUTCOME MEASURES: Difference in jump height between pre- and postintervention. Secondary outcomes were differences in handgrip strength and chair-rising test. RESULTS: Percentage change in jump height did not differ between those receiving vitamin D (25 or 10 µg vitamin D3) and those receiving placebo (mean difference -1.4%, 95% confidence interval: -4.9% to 2.2%, P=.44). No significant effect was detected in the subgroup randomized to 25 µg vitamin D or in other preplanned subgroup analyses nor were there any significant differences in handgrip strength or the chair-rising test. Mean serum 25-hydroxyvitamin D3 concentration increased from 27 to 52 nmol/L and from 27 to 43 nmol/L in the 25 and 10 µg supplementation groups, respectively, whereas serum 25-hydroxyvitamin D3 did not change in the placebo group. CONCLUSIONS: Daily supplementation with 25 or 10 µg vitamin D3 for 16 weeks did not improve muscle strength or power measured by the jump test, handgrip test, or chair-rising test in this population with low baseline vitamin D status.


Assuntos
Força Muscular/efeitos dos fármacos , Vitamina D/administração & dosagem , Adolescente , Adulto , Suplementos Nutricionais , Método Duplo-Cego , Etnicidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Grupos Minoritários , Noruega/etnologia , Placebos , Adulto Jovem
13.
BMC Cancer ; 12: 123, 2012 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-22458865

RESUMO

BACKGROUND: Studies indicate that strength training has beneficial effects on clinical health outcomes in prostate cancer patients during androgen deprivation therapy. However, randomized controlled trials are needed to scientifically determine the effectiveness of strength training on the muscle cell level. Furthermore, close examination of the feasibility of a high-load strength training program is warranted. The Physical Exercise and Prostate Cancer (PEPC) trial is designed to determine the effectiveness of strength training on clinical and muscle cellular outcomes in non-metastatic prostate cancer patients after high-dose radiotherapy and during ongoing androgen deprivation therapy. METHODS/DESIGN: Patients receiving androgen deprivation therapy for 9-36 months combined with external high-dose radiotherapy for locally advanced prostate cancer are randomized to an exercise intervention group that receives a 16 week high-load strength training program or a control group that is encouraged to maintain their habitual activity level. In both arms, androgen deprivation therapy is continued until the end of the intervention period.Clinical outcomes are body composition (lean body mass, bone mineral density and fat mass) measured by Dual-energy X-ray Absorptiometry, serological outcomes, physical functioning (muscle strength and cardio-respiratory fitness) assessed with physical tests and psycho-social functioning (mental health, fatigue and health-related quality of life) assessed by questionnaires. Muscle cellular outcomes are a) muscle fiber size b) regulators of muscle fiber size (number of myonuclei per muscle fiber, number of satellite cells per muscle fiber, number of satellite cells and myonuclei positive for androgen receptors and proteins involved in muscle protein degradation and muscle hypertrophy) and c) regulators of muscle fiber function such as proteins involved in cellular stress and mitochondrial function. Muscle cellular outcomes are measured on muscle cross sections and muscle homogenate from muscle biopsies obtained from muscle vastus lateralis. DISCUSSION: The findings from the PEPC trial will provide new knowledge on the effects of high-load strength training on clinical and muscle cellular outcomes in prostate cancer patients during androgen deprivation therapy. TRIAL REGISTRATION: ClinicalTrials.gov: NCT00658229.


Assuntos
Antagonistas de Androgênios/uso terapêutico , Músculo Esquelético/fisiopatologia , Neoplasias da Próstata/terapia , Treinamento Resistido/métodos , Composição Corporal/fisiologia , Terapia Combinada/efeitos adversos , Terapia Combinada/métodos , Terapia por Exercício/métodos , Fadiga , Estudos de Viabilidade , Humanos , Masculino , Força Muscular/fisiologia , Músculo Esquelético/anatomia & histologia , Neoplasias da Próstata/fisiopatologia , Neoplasias da Próstata/psicologia , Qualidade de Vida
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA