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1.
J Physiol ; 2024 Jun 11.
Artículo en Inglés | MEDLINE | ID: mdl-38861348

RESUMEN

Older adults are vulnerable to glucocorticoid-induced muscle atrophy and weakness, with sex potentially influencing their susceptibility to those effects. Aerobic exercise can reduce glucocorticoid-induced muscle atrophy in young rodents. However, it is unknown whether aerobic exercise can prevent glucocorticoid myopathy in aged muscle. The objectives of this study were to define the extent to which sex influences the development of glucocorticoid myopathy in aged muscle, and to determine the extent to which aerobic exercise training protects against myopathy development. Twenty-four-month-old female (n = 30) and male (n = 33) mice were randomized to either sedentary or aerobic exercise groups. Within their respective groups, mice were randomized to either daily treatment with dexamethasone (DEX) or saline. Upon completing treatments, the contractile properties of the triceps surae complex were assessed in situ. DEX marginally lowered muscle mass and soluble protein content in both sexes, which was attenuated by aerobic exercise only in females. DEX increased sub-tetanic force and rate of force development only in females, which was not influenced by aerobic exercise. Muscle fatigue was higher in both sexes following DEX, but aerobic exercise prevented fatigue induction only in females. The sex-specific differences to muscle function in response to DEX treatment coincided with sex-specific changes to the content of proteins related to calcium handling, mitochondrial quality control, reactive oxygen species production, and glucocorticoid receptor in muscle. These findings define several important sexually dimorphic changes to aged skeletal muscle physiology in response to glucocorticoid treatment and define the capacity of short-term aerobic exercise to protect against those changes. KEY POINTS: There are sexually dimorphic effects of glucocorticoids on aged skeletal muscle physiology. Glucocorticoid-induced changes to aged muscle contractile properties coincide with sex-specific differences in the content of calcium handling proteins. Aerobic exercise prevents glucocorticoid-induced fatigue only in aged females and coincides with differences in the content of mitochondrial quality control proteins and glucocorticoid receptors.

2.
J Korean Med Sci ; 37(13): e104, 2022 Apr 04.
Artículo en Inglés | MEDLINE | ID: mdl-35380028

RESUMEN

Vaccines have become the mainstay of management against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection (coronavirus disease 2019; COVID-19) in the absence of effective antiviral therapy. Various adverse effects of COVID-19 vaccination have been reported, including cardiovascular complications such as myocarditis or pericarditis. Herein, we describe clinical records of a 63-year woman with fulminant myocarditis following ChAdOx1 nCoV-19 vaccination that was salvaged by heart transplantation. She complained chest pain, nausea, vomiting, and fever after the second vaccination. After the heart transplantation, the patient died due to necrotizing pneumonia on the 54th day of onset. Fulminant myocarditis is very rare after ChAdOx1 nCoV-19 vaccination but can be fatal.


Asunto(s)
COVID-19 , Trasplante de Corazón , Miocarditis , Vacunas contra la COVID-19/efectos adversos , ChAdOx1 nCoV-19 , Femenino , Trasplante de Corazón/efectos adversos , Humanos , Miocarditis/complicaciones , Miocarditis/etiología , SARS-CoV-2 , Vacunación/efectos adversos
3.
J Cardiovasc Electrophysiol ; 31(11): 2898-2906, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-32945008

RESUMEN

BACKGROUND: Atrial tachyarrhythmias (ATAs) are common within the 3-month blanking period after catheter ablation of atrial fibrillation (AF). However, little evidence is available regarding the current guidelines on the blanking period after surgical AF ablation. We investigate the incidence and significance of early recurrence of atrial tachyarrhythmia (ERAT) and evaluate the optimal blanking period after surgical AF ablation. METHODS: Data from 259 patients who underwent surgical AF ablation from 2009 to 2016 were collected. ERAT was defined as documented ATA episodes lasting for 30 s. A multivariate Cox proportional hazard model was constructed to evaluate the role of ERAT as a predictor of late recurrences (LR) for AF. RESULTS: In total, 127 patients (49.0%) experienced their last episodes of ERAT during the first (n = 65), second (n = 14), or third (n = 48) month of the 3-month blanking period (p < .001). One year freedom from ATAs was 97.8% in patients without ERAT compared with 95.4%, 64.3%, and 8.3% in patients with ERAT in the first, second, and third months after the index procedure, respectively (p < .001). Hazard ratios of LR according to the timing of the last episode of ERAT first, second, and third months after the procedure were 2.84, 16.70, and 119.75, respectively. CONCLUSIONS: The ERAT occurred in 49.0% of patients within the first 3 months after surgical ablation. The occurrence of ERAT within 3 months after surgical AF ablation was a significant independent predictor of LR. Hence, the currently accepted 3-month blanking period may be considered for redefining in patients with AF surgical ablation.


Asunto(s)
Fibrilación Atrial , Ablación por Catéter , Venas Pulmonares , Fibrilación Atrial/diagnóstico , Fibrilación Atrial/epidemiología , Fibrilación Atrial/cirugía , Ablación por Catéter/efectos adversos , Humanos , Incidencia , Venas Pulmonares/cirugía , Recurrencia , Taquicardia , Resultado del Tratamiento
4.
J Nutr ; 150(1): 47-54, 2020 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-31504693

RESUMEN

BACKGROUND: To date, no studies have directly compared the differences between presleep and daytime protein (PRO) consumption on localized and systemic fat metabolism in active women. OBJECTIVE: The purpose of this study was to assess the effects of presleep compared with daytime PRO supplementation on subcutaneous abdominal adipose tissue (SCAAT) lipolysis and whole-body substrate utilization in women. METHODS: Thirteen young (mean ± SE age: 22 ± 1 y; BMI: 24.3 ± 0.8 kg/m2), resistance-trained [1 repetition maximum (1RM) squat percentage of body weight: 135% ± 6%; 1RM bench press percentage of body weight: 82% ± 4%] women volunteered. On overnight experimental visits, participants performed full-body resistance exercise (RE; 65% 1RM) and were randomly assigned to consume either daytime PRO (PRO, 30 g casein) 30 min post-RE and presleep (30 min before bed) noncaloric, sensory-matched placebo (PLA, 0 g casein) (PRO-PLA), or the opposite (PLA-PRO), switching the order of the supplements on the following visit. SCAAT lipolysis, resting metabolism (indirect calorimetry), and plasma biomarkers (glucose, insulin, nonesterified fatty acids, glycerol) were measured at baseline, overnight, and the next morning. RESULTS: There were no differences in overnight SCAAT lipolysis between conditions indicated by interstitial glycerol concentrations (PRO-PLA: baseline, 669 ± 137; next morning, 321 ± 77.1; PLA-PRO: baseline, 524 ± 109; next morning, 333 ± 68.0 µM), fat oxidation (PRO-PLA: baseline, 5.70 ± 0.35; next morning, 5.00 ± 0.28; PLA-PRO: baseline, 6.59 ± 0.32; next morning, 5.44 ± 0.27 g/min), or any other measure. CONCLUSIONS: There was no difference between the effects of daytime and presleep PRO supplementation on SCAAT lipolysis or whole-body substrate utilization in resistance-trained women. Presleep PRO is a viable option for increasing PRO consumption in resistance-trained women because it does not blunt overnight lipolysis, and will therefore likely not lead to increases in subcutaneous abdominal fat.This trial was registered at clinicaltrials.gov as NCT03573687.


Asunto(s)
Caseínas/administración & dosificación , Fenómenos Cronobiológicos/efectos de los fármacos , Metabolismo de los Lípidos/efectos de los fármacos , Lipólisis , Entrenamiento de Fuerza , Sueño , Caseínas/metabolismo , Fenómenos Cronobiológicos/fisiología , Estudios Cruzados , Proteínas en la Dieta , Método Doble Ciego , Metabolismo Energético , Femenino , Humanos , Oxidación-Reducción , Adulto Joven
5.
Circ J ; 84(9): 1582-1586, 2020 08 25.
Artículo en Inglés | MEDLINE | ID: mdl-32713874

RESUMEN

BACKGROUND: Dual antiplatelet therapy is commonly used for patients with acute coronary syndrome (ACS). This study aimed to evaluate the safety and efficacy of aspirin and prasugrel at standard dosages in Korean patients using clinical outcome data.Methods and Results:For this prospective multicenter phase IV post-marketing surveillance (PMS) study, ACS patients from 29 July 2012 to 28 July 2016 were recruited. Patients received aspirin at a dose of 75-150 mg daily and a standard dose of prasugrel. Bleeding events were recorded and summarized to evaluate safety. Data on adverse events (AEs) and composite events such as cardiovascular (CV) death, myocardial infarction (MI), and stroke were recorded and summarized to assess efficacy. Of the 3,283 patients recruited, data from 3,110 and 3,044 patients were included in the safety and efficacy analyses, respectively (median treatment duration, 172 days). The most frequently reported AE was ecchymosis (2.8%). The number of patients with major bleeding was 29/3,110 (0.93%). The discontinuation rate for any reason was 12.6%. The number of cases that ended in CV death, MI, stroke, stent thrombosis, or unplanned coronary revascularization was 26/3,044 (0.85%). CONCLUSIONS: The present results are similar to those observed in clinical trials where administration of low-dose aspirin plus prasugrel was associated with a low rate of major bleeding and CV events.


Asunto(s)
Síndrome Coronario Agudo/tratamiento farmacológico , Aspirina/efectos adversos , Trombosis Coronaria/inducido químicamente , Stents Liberadores de Fármacos/efectos adversos , Hemorragia/inducido químicamente , Infarto del Miocardio/inducido químicamente , Intervención Coronaria Percutánea/efectos adversos , Inhibidores de Agregación Plaquetaria/efectos adversos , Clorhidrato de Prasugrel/efectos adversos , Accidente Cerebrovascular/inducido químicamente , Síndrome Coronario Agudo/epidemiología , Anciano , Trombosis Coronaria/epidemiología , Quimioterapia Combinada , Femenino , Hemorragia/epidemiología , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Infarto del Miocardio/epidemiología , Estudios Prospectivos , República de Corea/epidemiología , Accidente Cerebrovascular/epidemiología , Resultado del Tratamiento
6.
Int J Mol Sci ; 20(10)2019 May 17.
Artículo en Inglés | MEDLINE | ID: mdl-31108916

RESUMEN

Transforming growth factor-beta (TGF-ß) isoforms are cytokines involved in a variety of cellular processes, including myofiber repair and regulation of connective tissue formation. Activation of the TGF-ß pathway contributes to pathologic fibrosis in most organs. Here, we have focused on examining the evidence demonstrating the involvement of TGF-ß in the fibrosis of skeletal muscle particularly. The TGF-ß pathway plays a role in different skeletal muscle myopathies, and TGF-ß signaling is highly induced in these diseases. In this review, we discuss different molecular mechanisms of TGF-ß-mediated skeletal muscle fibrosis and highlight different TGF-ß-targeted treatments that target these relevant pathways.


Asunto(s)
Músculo Esquelético/fisiología , Factor de Crecimiento Transformador beta/metabolismo , Animales , Fibrosis , Humanos , Músculo Esquelético/metabolismo , Transducción de Señal
7.
J Strength Cond Res ; 33(2): 337-345, 2019 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-28301439

RESUMEN

Ormsbee, MJ, Carzoli, JP, Klemp, A, Allman, BR, Zourdos, MC, Kim, J-S, and Panton, LB. Efficacy of the repetitions in reserve-based rating of perceived exertion for the bench press in experienced and novice benchers. J Strength Cond Res 33(2): 337-345, 2019-Autoregulation (AR) is the practice of adjusting training variables in response to athlete feedback. One component of AR postulated to enhance resistance training adaptations involves implementing a resistance training-specific rating of perceived exertion (RPE) scale measuring repetitions in reserve (RIR). The purpose of this study was to examine the efficacy of this method using the bench press exercise. Twenty-seven college-aged men were assigned to one of 2 groups based on training age: experienced benchers (EB) (n = 14, training age: 4.7 ± 2.0 years) and novice benchers (NB) (n = 13, training age: 1.1 ± 0.6 years). Subjects performed 1 repetition maximum (1RM) followed by single-repetition sets with loads corresponding to 60, 75, and 90% of 1RM and an 8-repetition set at 70% of 1RM. Subjects reported a corresponding RPE, based on RIR, for every set. Average velocity was recorded for each single-repetition set along with the first and last repetitions of the 8-repetition set at 70% of 1RM. Average velocity at 100% of 1RM in EB was slower (0.14 ± 0.04 m·s) compared with NB (0.20 ± 0.05 m·s) (p < 0.001). Experienced benchers recorded greater RPE than NB at 1RM (EB: 9.86 ± 0.14 vs. NB: 9.35 ± 0.36) (p = 0.011). No between-group differences existed for average velocity or RPE at any other intensity. Both EB (r = 0.85, p < 0.001) and NB (r = 0.85, p < 0.001) had strong inverse significant correlations between average velocity and RPE at all intensities. Our findings suggest that the RIR-based RPE scale may be an efficacious approach for AR of bench press training load and volume in college-aged men.


Asunto(s)
Fuerza Muscular/fisiología , Músculo Esquelético/fisiología , Entrenamiento de Fuerza/métodos , Levantamiento de Peso/fisiología , Humanos , Masculino , Percepción/fisiología , Esfuerzo Físico/fisiología , Universidades , Adulto Joven
8.
Small ; 14(25): e1800885, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-29806136

RESUMEN

A method is developed to directly map nanoscale "noise-source switching" phenomena during the optoelectronic switching of phase-separated polymer nanocomposites of tetrathiafulvalene (TTF) and phenyl-C61 -butyric acid methyl ester (PCBM) molecules dispersed in a polystyrene (PS) matrix. In the method, electrical current and noise maps of the nanocomposite film are recorded using a conducting nanoprobe, enabling the mapping of a conductivity and a noise-source density. The results provide evidence for a repeated modulation in noise sources, a "noise-source switching," in each stage of a switching cycle. Interestingly, when the nanocomposite is "set" by a high bias, insulating PS-rich phases shows a drastic decrease in a noise-source density which becomes lower than that of conducting TTF-PCBM-rich phases. This can be attributed to a trap filling by charge carriers generated from a TTF (donor)-PCBM (acceptor) complex. In addition, when the film is exposed to UV, an optical switching occurs due to chemical reactions which lead to irreversible changes on the noise-source density and conductivity. The method provides a new insight on noise-source activities during the optoelectronic switching of polymer nanocomposites and thus can be a powerful tool for basic noise research and applications in organic memory devices.

9.
Eur J Appl Physiol ; 118(10): 2065-2076, 2018 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-30003382

RESUMEN

PURPOSE: The objective of this study was to examine the effects of repeated long-duration water immersions (WI)s at 1.35 atmospheres absolute (ATA) on neuromuscular performance in load bearing and non-load bearing muscle groups. METHODS: During a dive week (DW), fifteen well-trained male divers completed five consecutive 6-h resting dives with 18-h surface intervals while breathing compressed air at 1.35 ATA. Skeletal muscle performance assessments occurred immediately before and after each WI, and 24 and 72 h after the final WI. Exercise assessments included maximum voluntary isometric contraction (MVIC), maximal isokinetic (IK) contraction, maximum handgrip strength (MHG). Surface electromyography measured neuromuscular activation of the quadriceps, biceps brachii (BB), and brachioradialis. RESULTS: MVIC torque of knee extensors and BB decreased by 6% (p = 0.001) and 2% (p = 0.014), respectively, by WI 3. Maximal IK torque of knee extensors increased by 11 and 5% post-WI on WIs 3 and 5 (p < 0.001) with greater neuromuscular activation post-WI than pre-WI (p < 0.001). Maximum IK elbow flexion torque did not change throughout the DW with BB neuromuscular activation greater post-WI than pre-WI (p < 0.001). MHG force output was 4% greater post-WI than pre-WI (p < 0.001) with increased brachioradialis activation through 72-h post-WI (p < 0.001). All muscle performance metrics returned baseline levels by 72-h post-WI. CONCLUSION: Our findings indicate that repeated WIs caused noticeable decrements in neuromuscular activation and performance of load bearing muscles on WI 3 while full recovery was observed by 72-h post-WI.


Asunto(s)
Buceo/fisiología , Ejercicio Físico/fisiología , Músculo Esquelético/fisiología , Adulto , Brazo/fisiología , Codo/fisiología , Articulación del Codo/fisiología , Electromiografía/métodos , Fuerza de la Mano/fisiología , Humanos , Contracción Isométrica/fisiología , Rodilla/fisiología , Articulación de la Rodilla/fisiología , Masculino , Fatiga Muscular/fisiología , Rango del Movimiento Articular/fisiología , Factores de Tiempo , Torque , Agua
10.
Exp Physiol ; 102(11): 1500-1512, 2017 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-28795443

RESUMEN

NEW FINDINGS: What is the central question of this study? This study examined the effects of 20 weeks of administration of conjugated linoleic acids/omega-3 fatty acids with or without programed resistance exercise training on body composition, skeletal muscle properties and functional capacity in middle-aged mice fed a high-fat diet. What is the main finding and its importance? Chronic daily administration of conjugated linoleic acids/omega-3 fatty acids with resistance exercise training can help to blunt fat gain, alleviate loss of myogenic capacity and sensorimotor function and lower tissue inflammation in middle-aged mice during chronic high-fat diet-induced catabolism. This study investigated the effects of 20 weeks of combined conjugated linoleic acid (CLA)/omega-3 fatty acid (n-3) administration independently or combined with resistance exercise training (RET) on skeletal muscle in middle-aged mice consuming a high-fat diet (HFD). Nine-month-old C57BL/6 mice were randomly assigned into four experimental groups (H, high-fat diet; HE, H + RET; HCN, H + CLA/n-3; and HECN, H + CLA/n3 + RET). Body composition and functional capacity were assessed pre- and post-intervention. Muscle tissues were collected at 14 months of age. ANOVA was used, with significance set at P ≤ 0.05. Fat mass significantly increased in H (+74%), HE (+142%) and HECN (+43%) but not in HCN. Muscle wet weights were significantly lower in H and HCN than in HE and HECN. Grip strength substantially declined in H (-15%) and HCN (-17%), whereas sensorimotor function significantly declined only in H (-11%). HECN exhibited improvement in strength (+22%) and sensorimotor coordination (+17%). In comparison to H, muscle tumour necrosis factor-α mRNA expression was significantly lower in HE (-39%), HCN (-24%) and HECN (-21%), respectively. Mean myofibre cross-sectional areas were markedly lower in H and HCN than in HE and HECN. H showed significantly lower satellite cell abundance and numbers of myonuclei than all other groups. Our findings suggest that long-term daily CLA/n-3 intake with resistance training improved sensorimotor function, ameliorated fat gain and prevented loss of myogenic capacity while lowering tumour necrosis factor-α expression during chronic HFD.


Asunto(s)
Dieta Alta en Grasa , Suplementos Dietéticos , Ácidos Grasos Omega-3/administración & dosificación , Ácidos Linoleicos Conjugados/administración & dosificación , Músculo Esquelético/efectos de los fármacos , Obesidad/prevención & control , Entrenamiento de Fuerza , Adiposidad/efectos de los fármacos , Factores de Edad , Animales , Caspasa 3/genética , Caspasa 3/metabolismo , Modelos Animales de Enfermedad , Regulación de la Expresión Génica , Mediadores de Inflamación/metabolismo , Masculino , Ratones Endogámicos C57BL , Fuerza Muscular/efectos de los fármacos , Músculo Esquelético/metabolismo , Músculo Esquelético/patología , Músculo Esquelético/fisiopatología , Obesidad/metabolismo , Obesidad/patología , Obesidad/fisiopatología , Desempeño Psicomotor/efectos de los fármacos , Factores de Tiempo , Factor de Necrosis Tumoral alfa/genética , Factor de Necrosis Tumoral alfa/metabolismo , Aumento de Peso/efectos de los fármacos
11.
Catheter Cardiovasc Interv ; 89(2): 219-225, 2017 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-27535003

RESUMEN

OBJECTIVES: The aim of this study was to explore the effect of one stenosis in a daughter artery on the fractional flow reserve (FFR) of another stenosis parallels in side branch. BACKGROUND: The impact of one stenosis on the FFR of another parallel stenosis has not been evaluated. METHODS: The proximal segments of the left anterior descending (LAD) and left circumflex (LCX) arteries were exposed and encircled with a Teflon pledget complex in seven swine (55-70 kg). Five degrees of stenosis (to approximate angiographic diameter stenoses of 0%, 25%, 50%, 75%, and 100%) were made by tightening the pledgets. FFR was evaluated simultaneously in the LAD and the LCX with two pressure wires in each coronary artery. A mixed-effects linear model was used to evaluate the association between the FFR values. RESULTS: A total of 115 paired FFR values were obtained. The FFR of the LAD and LCX were not significantly associated with each other (F = 0.237 and P = 0.627 for the LCX FFR to predict the LAD FFR; F = 0.541 and P = 0.463 for the LAD FFR to predict the LCX FFR). CONCLUSIONS: The individual FFR values of each parallel stenosis in the LAD and the LCX were not significantly influenced by each other. This relationship was independent of the mean aortic pressure and heart rate. © 2016 Wiley Periodicals, Inc.


Asunto(s)
Estenosis Coronaria/fisiopatología , Vasos Coronarios/fisiopatología , Reserva del Flujo Fraccional Miocárdico , Animales , Aorta/fisiopatología , Presión Arterial , Cateterismo Cardíaco , Angiografía Coronaria , Estenosis Coronaria/diagnóstico por imagen , Vasos Coronarios/diagnóstico por imagen , Modelos Animales de Enfermedad , Frecuencia Cardíaca , Modelos Lineales , Masculino , Modelos Cardiovasculares , Análisis Multivariante , Índice de Severidad de la Enfermedad , Porcinos
12.
Support Care Cancer ; 25(1): 9-15, 2017 01.
Artículo en Inglés | MEDLINE | ID: mdl-27516182

RESUMEN

ᅟ: Breast cancer survivors (BCS) have been told in the past to avoid strenuous repetitive activities in order to decrease the risk of lymphedema development. Recent evidence suggests that exercise may be beneficial to decrease the signs/symptoms and development of lymphedema. PURPOSE/METHODS: This study assessed the arm circumferences of 27 BCS (64 ± 7 years) at baseline and every 2 weeks thereafter during a 6-month resistance exercise training (RT) intervention. RT consisted of 2 days/week of 10 exercises including two sets of 8-12 repetitions at 52-69 % of the participants' one-repetition maximum. RESULTS: A repeated measure analysis of variance revealed no significant changes in percent difference of arm circumferences at any assessment point (pre, 1.31 ± 6.21 %; post, 0.62 ± 6.55 %), nor were there any adverse lymphedema-related events reported during the study. CONCLUSIONS: These findings imply that RT can be a safe activity for women with or at risk for breast cancer-related lymphedema.


Asunto(s)
Linfedema del Cáncer de Mama/etiología , Ejercicio Físico/fisiología , Entrenamiento de Fuerza/métodos , Linfedema del Cáncer de Mama/patología , Femenino , Humanos , Persona de Mediana Edad , Riesgo , Sobrevivientes
13.
Clin J Sport Med ; 26(2): 152-6, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25706662

RESUMEN

OBJECTIVE: To compare measures of training, performance, body composition, and areal bone mineral density (aBMD) between age-matched recreational and competitively trained male road cyclists. DESIGN: Cross-sectional. SETTING: Laboratory. PARTICIPANTS: Male cyclists (N = 28) aged 21-54 years riding more than 3 hours per week. ASSESSMENT OF RISK FACTORS: Men who train at high (≥8 h/wk) and moderate volumes (3-8 h/wk). MAIN OUTCOME MEASURES: Areal bone mineral density assessments by dual energy x-ray absorptiometry of the whole body, lumbar spine (L1-L4), right and left hips, maximal oxygen uptake (V[Combining Dot Above]O2max), and training history. RESULTS: Trained cyclists had higher power to weight (5.3 ± 0.4 vs 4.7 ± 0.3 W/kg, P = 0.001), V[Combining Dot Above]O2max (57.2 ± 4.5 vs 53.0 ± 6.1 mL·kg·min, P = 0.049) and training volume (10.6 ± 2.1 vs 6.3 ± 0.9 h/wk, P < 0.001) than recreational cyclists. Trained cyclists had lower right (0.898 ± 0.090 vs 0.979 ± 0.107 g/cm, P = 0.047) and left hip aBMD (0.891 ± 0.079 vs 0.973 ± 0.104 g/cm, P = 0.032). Z-scores identified lumbar (L1-L4) aBMD as osteopenic (-2.5 < Z-score < -1.0) in trained cyclists (-1.39 ± 1.09). Lumbar scans identified 12 trained and 4 recreational cyclists as osteopenic and 3 trained cyclists as osteoporotic. CONCLUSIONS: Areal bone mineral density is lower in trained male road cyclists compared with recreational, specifically at the hips. Lumbar aBMD is low in both trained and recreational cyclists. Research is needed to determine the chronic effects of cycling on aBMD and interventions that improve aBMD in this population. CLINICAL RELEVANCE: This study suggests road cycling may compromise aBMD and potentially increase the likelihood of low-trauma fractures; health care professionals should consider this exposure when exercise prescriptions are designed for patients at-risk for osteopenia/osteoporosis, for example, women and older adults.


Asunto(s)
Atletas/estadística & datos numéricos , Rendimiento Atlético/fisiología , Ciclismo/fisiología , Densidad Ósea , Adulto , Estudios Transversales , Humanos , Masculino , Persona de Mediana Edad , Adulto Joven
14.
J Strength Cond Res ; 30(3): 784-91, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26332783

RESUMEN

The primary aim of this study was to compare 2 daily undulating periodization (DUP) models on one-repetition maximum (1RM) strength in the squat, bench press, deadlift, total volume (TV) lifted, and temporal hormone response. Eighteen male, college-aged (21.1 ± 1.9 years) powerlifters participated in this study and were assigned to one of 2 groups: (a) traditional DUP training with a weekly training order: hypertrophy-specific, strength-specific, and power-specific training (HSP, n = 9) or (b) modified DUP training with a weekly training order: hypertrophy-specific, power-specific, and strength-specific training (HPS, n = 9). Both groups trained 3 nonconsecutive days per week for 6 weeks and performed the squat, bench press, and deadlift exercises. During hypertrophy and power sessions, subjects performed a fixed number of sets and repetitions but performed repetitions until failure at a given percentage during strength sessions to compare TV. Testosterone and cortisol were measured at pretesting and posttesting and before each strength-specific day. Hypertrophy, power, and strength produced greater TV in squat and bench press (p ≤ 0.05) than HSP, but not for deadlift (p > 0.05). For squat and deadlift, there was no difference between groups for 1RM (p > 0.05); however, HPS exhibited greater increases in 1RM bench press than HSP (p ≤ 0.05). Effect sizes (ES) showed meaningful differences (ES > 0.50) in favor of HPS for squat and bench press 1RM. Testosterone decreased (p ≤ 0.05) at weeks 5 and 6 and cortisol decline at weeks 3 and 4. However, neither hormone was different at posttesting compared with pretesting (p > 0.05). Our findings suggest that an HPS configuration of DUP has enhanced performance benefits compared with HSP.


Asunto(s)
Fuerza Muscular , Entrenamiento de Fuerza/métodos , Levantamiento de Peso/fisiología , Adulto , Prueba de Esfuerzo , Humanos , Hidrocortisona/sangre , Masculino , Modelos Biológicos , Testosterona/sangre , Adulto Joven
15.
Can J Diet Pract Res ; 77(2): 98-102, 2016 06.
Artículo en Inglés | MEDLINE | ID: mdl-26568150

RESUMEN

PURPOSE: To describe body composition (fat mass (FM) and fat-free mass (FFM)), strength, and nutritional characteristics of patients with hip or knee osteoarthritis undergoing total joint arthroplasty. METHODS: In this prospective pilot study, osteoarthritic patients underwent body composition assessment using bioelectrical impedance analysis, grip strength measurement, and completed a 24-h dietary recall during their pre-operative assessment. RESULTS: Fifty-five patients were included (∼66% females, age 43-89 years). Mean ± SD body mass index (BMI) was 32.79 ± 6.48 kg/m(2) and 62% were obese. Compared with hip osteoarthritis patients, knee osteoarthritis patients had a higher BMI (P = 0.018) and males with knee osteoarthritis had a lower grip strength (P = 0.028). There was a wide range in FM and FFM values across the BMI spectrum. Patients with a higher FM index (FMI, FM/height in m(2)) had higher levels of pain (P = 0.036) and females with higher FMI had a lower grip strength (P = 0.048). Dietary under-reporting was common and many patients did not meet recommendations for protein, vitamins C and E, or omega-3 fatty acids. Those who consumed less protein than the recommended dietary allowance were older (P = 0.018). CONCLUSIONS: A wide variability of body composition and dietary intake was observed which may impact strength and ultimately affect physical function. As such, patients with osteoarthritis may benefit from targeted nutrition and physical activity interventions before and after surgery.


Asunto(s)
Composición Corporal , Dieta , Fuerza de la Mano , Osteoartritis de la Cadera/fisiopatología , Osteoartritis de la Rodilla/fisiopatología , Adulto , Anciano , Anciano de 80 o más Años , Ácido Ascórbico/administración & dosificación , Ácido Ascórbico/análisis , Índice de Masa Corporal , Proteínas en la Dieta/administración & dosificación , Proteínas en la Dieta/análisis , Impedancia Eléctrica , Ejercicio Físico , Ácidos Grasos Omega-3/administración & dosificación , Ácidos Grasos Omega-3/análisis , Femenino , Humanos , Masculino , Recuerdo Mental , Persona de Mediana Edad , Estado Nutricional , Obesidad/fisiopatología , Proyectos Piloto , Estudios Prospectivos , Ingesta Diaria Recomendada , Vitamina E/administración & dosificación , Vitamina E/análisis
16.
Aging Clin Exp Res ; 27(4): 403-11, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-25647784

RESUMEN

BACKGROUND AND AIMS: Increased adipose tissue may promote catabolic events in skeletal muscle. The aim of this study was to test whether high-fat diet (HFD)-induced obesity would accelerate the onset of muscle wasting in middle-aged mice. METHODS: Muscle was collected from C57BL/6 mice at 9 months of age (baseline) and 14 months of age after consuming a control (C) or HFD. Mice in C and HFD were also subjected to evaluations of body composition and function before and after their respective diets. RESULTS: HFD demonstrated significant (p < 0.05) losses of grip strength (-15 %) and sensorimotor coordination (-11 %), whereas C did not. Lean mass decreased to a greater degree in HFD although not significantly (C: -20.69 ± 7.94 vs. HFD: -31.14 ± 5.49 %, p > 0.05). Gastrocnemius, quadriceps, and hamstrings mass in C and HFD were significantly reduced from baseline (-27 to 43 and -39 to 47 %, respectively, p < 0.05) with no differences between the two; however, soleus mass was lower only in HFD (-24 %, p = 0.03). Myofiber area, satellite cells, and myonuclei of the gastrocnemius were lower only in HFD (-23, -19, and -16 %, respectively, p < 0.05) compared to baseline. CONCLUSIONS: HFD-induced obesity adversely affected function in middle-aged mice. Atrophy of the soleus in HFD but not C suggests sensitivity of oxidative muscle to HFD-dependent catabolism more so than aging. In the muscles containing fast/mixed fibers, aging effects may have concealed the catabolic nature of HFD; however, morphological changes in the gastrocnemius including decreased fiber area, satellite cells, and myonuclei are consistent with an atrophic phenotype related to HFD.


Asunto(s)
Tejido Adiposo , Dieta Alta en Grasa/efectos adversos , Metabolismo/fisiología , Músculo Esquelético , Atrofia Muscular , Obesidad/metabolismo , Tejido Adiposo/metabolismo , Tejido Adiposo/patología , Animales , Composición Corporal , Modelos Animales de Enfermedad , Masculino , Ratones , Ratones Endogámicos C57BL , Músculo Esquelético/patología , Músculo Esquelético/fisiología , Atrofia Muscular/etiología , Atrofia Muscular/metabolismo , Atrofia Muscular/patología , Obesidad/etiología , Obesidad/patología , Tamaño de los Órganos , Oxidación-Reducción
17.
J Strength Cond Res ; 29(8): 2270-6, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-25647658

RESUMEN

A single bout of unaccustomed exercise confers protective effect against muscle damage from a subsequent bout of similar activity, that is, repeated bout effect (RBE). It remains unknown whether varying muscle-specific exercise between sessions alters the magnitude of the RBE. This study examined the effects of muscle-specific exercise variation between consecutive sessions on the RBE. Twenty untrained males (21 ± 2 years) were assigned to one of 2 groups (n = 10 per group): (a) 2 sessions of incline curls, Fixed Exercise or (b) 1 session of incline curls followed by 1 session of preacher curls, Varied Exercise, with 7 days between sessions. Subjects performed 5 sets of 6 repetitions at ∼50% of maximal isometric elbow flexor strength during each session. Changes in maximal voluntary isometric and isokinetic torque, range of motion, muscle soreness, and serum creatine kinase were measured before, immediately after, and 24, 48, 72, and 96 hours after each exercise session, and the changes were compared between bouts and between groups. There were significant time effects (p < 0.05) for isometric maximal voluntary contraction, concentric maximal voluntary contraction, range of motion, and muscle soreness during sessions 1 and 2 with no between-group differences. Both groups demonstrated a significantly faster recovery of range of motion and soreness to baseline levels after session 2 compared with session 1. Overall, our findings suggest that incline curls conferred a protective effect during subsequent preacher curls in a similar way to repeating incline curls; therefore, the RBE was not exercise specific.


Asunto(s)
Músculo Esquelético/fisiología , Entrenamiento de Fuerza/métodos , Adolescente , Creatina Quinasa/sangre , Articulación del Codo/fisiología , Ejercicio Físico/fisiología , Humanos , Contracción Isométrica , Masculino , Músculo Esquelético/patología , Mialgia/etiología , Rango del Movimiento Articular , Recuperación de la Función , Entrenamiento de Fuerza/efectos adversos , Factores de Tiempo , Torque , Adulto Joven
18.
Br J Nutr ; 112(3): 320-7, 2014 Aug 14.
Artículo en Inglés | MEDLINE | ID: mdl-24833598

RESUMEN

The present study investigated whether whey (WH) protein, casein (CAS) protein or a carbohydrate placebo (PLA) consumed 30 min before sleep could acutely alter appetite or cardiometabolic risk the following morning. A total of forty-four sedentary overweight and obese women (BMI: 25·7-54·6 kg/m2) completed this stratified, randomised, double-blind, placebo-controlled study (WH: n 16, age 27·4 (sd 5·0) years; CAS: n 15, age 30·3 (sd 8·1) years; PLA: n 13, age 28·5 (sd 7·2) years). The participants came to the laboratory at baseline (visit 1) and again in the morning after night-time ingestion of either protein or PLA (visit 2). Visit 2 was conducted at least 48 h after visit 1. During visits 1 and 2, the following parameters were measured: appetite (hunger, satiety and desire to eat); resting metabolism; blood lipid and glucose levels; the levels of insulin, leptin, C-reactive protein, insulin-like growth factor-1, cortisol and adiponectin. Data were analysed using repeated-measures ANOVA. No group × time interactions were observed for the measured variables; however, a main effect of time was observed for increased satiety (P= 0·03), reduced desire to eat (P= 0·006), and increased insulin levels (P= 0·004) and homeostatic model assessment of insulin resistance values (P= 0·01) after the consumption of either protein or PLA. The results of the present study reveal that night-time consumption of protein or carbohydrate by sedentary overweight and obese women improves their appetite measures but negatively affects insulin levels. Long-term studies are needed to evaluate the effects of chronic consumption of low-energy snacks at night on body composition and cardiometabolic risk.


Asunto(s)
Apetito/efectos de los fármacos , Enfermedades Cardiovasculares , Carbohidratos de la Dieta/administración & dosificación , Proteínas en la Dieta/administración & dosificación , Enfermedades Metabólicas , Sobrepeso/fisiopatología , Adolescente , Adulto , Presión Sanguínea , Caseínas/administración & dosificación , Ritmo Circadiano , Método Doble Ciego , Ingestión de Energía , Femenino , Hormonas/sangre , Humanos , Insulina/sangre , Resistencia a la Insulina , Lípidos/sangre , Persona de Mediana Edad , Proteínas de la Leche/administración & dosificación , Obesidad/fisiopatología , Factores de Riesgo , Conducta Sedentaria , Sueño , Proteína de Suero de Leche
19.
Ethn Dis ; 24(3): 356-62, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25065079

RESUMEN

Our cross-sectional study investigated the relationships between regional bone mineral density (BMD) and body composition variables, including total body lean mass (LM) and fat mass (FM), as well as muscular strength in overweight and obese African-American (AA) women with metabolic syndrome (MetS). Forty-four women ranging in age from 39 to 61 years participated. Upper and lower body strength measurements were assessed using chest press and leg extension exercises, respectively. Body composition and BMD of the total body, spine (L2-L4), hip, and radius were measured by dual-energy X-ray absorptiometry. LM was positively correlated with total body, spine, hip, and radius BMD (r = .338-.603, all P < .05), and FM was positively correlated with total body BMD (r = .343, P < .05). In multiple linear regression analyses after controlling for age, height, total energy, and calcium intake, LM was a significant positive determinant of BMD at various skeletal sites (P < .05), while FM was negatively related to BMD of total hip (P < .05). Our results indicate that LM is an independent predictor of total body, spine, hip, and total radius BMD. In contrast, FM is a negative predictor of total body and hip BMD in overweight or obese AA women with MetS (P < .05). Upper and lower body muscular strength measures were not associated with BMD at any skeletal sites. These results suggest an important role for LM in preventing the development of osteopenia and osteoporosis.


Asunto(s)
Negro o Afroamericano , Composición Corporal , Densidad Ósea , Síndrome Metabólico/etnología , Fuerza Muscular , Obesidad/etnología , Adulto , Estudios Transversales , Femenino , Humanos , Síndrome Metabólico/fisiopatología , Persona de Mediana Edad , Obesidad/metabolismo , Valor Predictivo de las Pruebas , Factores de Riesgo
20.
Acta Cardiol ; 69(6): 628-34, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25643433

RESUMEN

BACKGROUND: Little is known about the effects of selective intracoronary administration of ergonovine into a coronary artery on the artery on the other side. This study aimed to evaluate the effect of intracoronarily administered ergonovine on the contralateral coronary artery. SUBJECTS AND METHODS: From June 2011 to August 2013, coronary spasm provocation tests were performed in 85 consecutive patients using selective intracoronary administration of methylergometrine maleate (ER).The doses increased in a step-wise manner up to 60 µg for the left coronary artery (LCA) and up to 50 µg for the right coronary artery (RCA).The coronary artery diameters were measured and analysed by repeated-measures ANOVA. RESULTS: Twenty-four (28%) patients had a spasm-positive result. The mean diameter of the spasm segment in the contralateral artery decreased from 2.83 to 2.68 mm (5.1 ± 0.1% change, P < 0.001) in the negative spasm group and from 2.40 to 2.10 mm (11.1 ± 2.2% change, P = 0.001) in the positive spasm group. There were no serious procedure-related complications. CONCLUSIONS: Intracoronary administration of ER resulted in a statistically significant decrease of lumen diameter of the contralateral coronary artery. However, from the clinical perspective, the extent of the decrease was relatively small and the test may be conducted safely unless there is a significant coronary artery luminal narrowing.


Asunto(s)
Angina Pectoris Variable/diagnóstico , Vasoespasmo Coronario/inducido químicamente , Vasos Coronarios/efectos de los fármacos , Ergonovina/administración & dosificación , Oxitócicos/administración & dosificación , Angiografía Coronaria , Femenino , Humanos , Inyecciones Intraarteriales , Masculino , Persona de Mediana Edad
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