RESUMO
Metabolic syndrome (MetS) is the manifestation of a cluster of cardiovascular risk factors and is associated with a threefold increase in the risk of cardiovascular morbidity and mortality, which is suggested to be mediated, in part, by resting left ventricular (LV) systolic dysfunction. However, to what extent resting LV systolic function is impaired in MetS is controversial, and there are no data indicating whether LV systolic function is impaired during exercise. Accordingly, the objective of this study was to examine comprehensively the LV and arterial responses to exercise in individuals with MetS without diabetes and/or overt cardiovascular disease in comparison to a healthy control population. Cardiovascular function was characterized using Doppler echocardiography and gas exchange in individuals with MetS (n = 27) versus healthy control subjects (n = 20) at rest and during peak exercise. At rest, individuals with MetS displayed normal LV systolic function but reduced LV diastolic function compared with healthy control subjects. During peak exercise, individuals with MetS had impaired contractility, pump performance and vasodilator reserve capacity versus control subjects. A blunted contractile reserve response resulted in diminished arterial-ventricular coupling reserve and limited aerobic capacity in individuals with MetS versus control subjects. These findings are of clinical importance, because they provide insight into the pathophysiological changes in MetS that may predispose this population of individuals to an increased risk of cardiovascular morbidity and mortality.
Assuntos
Exercício Físico/fisiologia , Síndrome Metabólica/fisiopatologia , Sístole/fisiologia , Função Ventricular Esquerda/fisiologia , Diástole/fisiologia , Tolerância ao Exercício/fisiologia , Feminino , Ventrículos do Coração/diagnóstico por imagem , Ventrículos do Coração/fisiopatologia , Humanos , Masculino , Síndrome Metabólica/diagnóstico por imagem , Pessoa de Meia-Idade , Ultrassonografia , Disfunção Ventricular Esquerda/diagnóstico por imagem , Disfunção Ventricular Esquerda/fisiopatologiaRESUMO
Older men (n = 12) and women (n = 18) 65-80 years of age completed 12 weeks of exercise and took either a placebo or resveratrol (RSV) (500 mg/d) to test the hypothesis that RSV treatment combined with exercise would increase mitochondrial density, muscle fatigue resistance, and cardiovascular function more than exercise alone. Contrary to our hypothesis, aerobic and resistance exercise coupled with RSV treatment did not reduce cardiovascular risk further than exercise alone. However, exercise added to RSV treatment improved the indices of mitochondrial density, and muscle fatigue resistance more than placebo and exercise treatments. In addition, subjects that were treated with RSV had an increase in knee extensor muscle peak torque (8%), average peak torque (14%), and power (14%) after training, whereas exercise did not increase these parameters in the placebo-treated older subjects. Furthermore, exercise combined with RSV significantly improved mean fiber area and total myonuclei by 45.3% and 20%, respectively, in muscle fibers from the vastus lateralis of older subjects. Together, these data indicate a novel anabolic role of RSV in exercise-induced adaptations of older persons and this suggests that RSV combined with exercise might provide a better approach for reversing sarcopenia than exercise alone.
Assuntos
Adaptação Fisiológica/efeitos dos fármacos , Antioxidantes/farmacologia , Exercício Físico/fisiologia , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/fisiologia , Células Satélites de Músculo Esquelético/efeitos dos fármacos , Células Satélites de Músculo Esquelético/fisiologia , Estilbenos/farmacologia , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Método Duplo-Cego , Feminino , Humanos , Masculino , Fadiga Muscular/efeitos dos fármacos , ResveratrolRESUMO
PURPOSE: The metabolic syndrome (MetS) is associated with threefold increased risk of cardiovascular (CV) morbidity and mortality, which is partly due to a blunted CV reserve capacity, reflected by a reduced peak exercise left ventricular (LV) contractility and aerobic capacity and a blunted peak arterial-ventricular coupling. To date, no study has examined whether aerobic exercise training in MetS can reverse peak exercise CV dysfunction. Furthermore, examining how exercise training alters CV function in a group of individuals with MetS before the development of diabetes and/or overt CV disease can provide insights into whether some of the pathophysiological CV changes can be delayed/reversed, lowering their CV risk. The objective of this study was to examine the effects of 8 wk of aerobic exercise training in individuals with MetS on resting and peak exercise CV function. METHODS: Twenty participants with MetS underwent either 8 wk of aerobic exercise training (MetS-ExT, n = 10) or remained sedentary (MetS-NonT, n = 10) during this period. Resting and peak exercise CV function was characterized using Doppler echocardiography and gas exchange. RESULTS: Exercise training did not alter resting LV diastolic or systolic function and arterial-ventricular coupling in MetS. In contrast, at peak exercise, an increase in LV contractility (40%, P < 0.01), cardiac output (28%, P < 0.05), and aerobic capacity (20%, P < 0.01), but a reduction in vascular resistance (30%, P < 0.05) and arterial-ventricular coupling (27%, P < 0.01), were noted in the MetS-ExT but not in the MetS-NonT group. Furthermore, an improvement in lifetime risk score was also noted in the MetS-ExT group. CONCLUSIONS: These findings have clinical importance because they provide insight that some of the pathophysiological changes associated with MetS can be improved and can lower the risk of CV disease.
Assuntos
Exercício Físico/fisiologia , Síndrome Metabólica/fisiopatologia , Síndrome Metabólica/terapia , Função Ventricular Esquerda/fisiologia , Adulto , Limiar Anaeróbio , Ecocardiografia Doppler , Terapia por Exercício , Tolerância ao Exercício/fisiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Contração Miocárdica , Consumo de Oxigênio , Projetos Piloto , Troca Gasosa Pulmonar , Descanso/fisiologia , Volume Sistólico , Resistência VascularRESUMO
The metabolic syndrome (MetS) is associated with a threefold increase risk of cardiovascular disease (CVD) mortality partly due to increased arterial stiffening. We compared the effects of aerobic exercise training on arterial stiffening/mechanics in MetS subjects without overt CVD or type 2 diabetes. MetS and healthy control (Con) subjects underwent 8 wk of exercise training (ExT; 11 MetS and 11 Con) or remained inactive (11 MetS and 10 Con). The following measures were performed pre- and postintervention: radial pulse wave analysis (applanation tonometry) was used to measure augmentation pressure and index, central pressures, and an estimate of myocardial efficiency; arterial stiffness was assessed from carotid-femoral pulse-wave velocity (cfPWV, applanation tonometry); carotid thickness was assessed from B-mode ultrasound; and peak aerobic capacity (gas exchange) was performed in the seated position. Plasma matrix metalloproteinases (MMP) and CVD risk (Framingham risk score) were also assessed. cfPWV was reduced (P < 0.05) in MetS-ExT subjects (7.9 ± 0.6 to 7.2 ± 0.4 m/s) and Con-ExT (6.6 ± 1.8 to 5.6 ± 1.6 m/s). Exercise training reduced (P < 0.05) central systolic pressure (116 ± 5 to 110 ± 4 mmHg), augmentation pressure (9 ± 1 to 7 ± 1 mmHg), augmentation index (19 ± 3 to 15 ± 4%), and improved myocardial efficiency (155 ± 8 to 168 ± 9), but only in the MetS group. Aerobic capacity increased (P < 0.05) in MetS-ExT (16.6 ± 1.0 to 19.9 ± 1.0) and Con-ExT subjects (23.8 ± 1.6 to 26.3 ± 1.6). MMP-1 and -7 were correlated with cfPWV, and both MMP-1 and -7 were reduced post-ExT in MetS subjects. These findings suggest that some of the pathophysiological changes associated with MetS can be improved after aerobic exercise training, thereby lowering their cardiovascular risk.
Assuntos
Artérias/fisiopatologia , Terapia por Exercício/métodos , Síndrome Metabólica/fisiopatologia , Síndrome Metabólica/terapia , Doença Arterial Periférica/prevenção & controle , Doença Arterial Periférica/fisiopatologia , Rigidez Vascular , Adulto , Pressão Arterial , Exercício Físico , Humanos , Masculino , Condicionamento Físico Humano/métodos , Resultado do TratamentoRESUMO
Rheumatoid arthritis (RA) is a chronic, systemic, autoimmune, inflammatory disease associated with cachexia (reduced muscle and increased fat). Although strength-training exercise has been used in persons with RA, it is not clear if it is effective for reducing cachexia. A 46-year-old woman was studied to determine: (i) if resistance exercise could reverse cachexia by improving muscle mass, fiber cross-sectional area, and muscle function; and (2) if elevated apoptotic signaling was involved in cachexia with RA and could be reduced by resistance training. A needle biopsy was obtained from the vastus lateralis muscle of the RA subject before and after 16 weeks of resistance training. Knee extensor strength increased by 13.6% and fatigue decreased by 2.8% Muscle mass increased by 2.1%. Average muscle fiber cross-sectional area increased by 49.7%, and muscle nuclei increased slightly after strength training from 0.08 to 0.12 nuclei/µm(2). In addition, there was a slight decrease (1.6%) in the number of apoptotic muscle nuclei after resistance training. This case study suggests that resistance training may be a good tool for increasing the number of nuclei per fiber area, decreasing apoptotic nuclei, and inducing fiber hypertrophy in persons with RA, thereby slowing or reversing rheumatoid cachexia.