Aerobic exercise attenuates dysautonomia, cardiac diastolic dysfunctions, and hemodynamic overload in female mice with atherosclerosis.

Cardiovascular risk increases during the aging process in women with atherosclerosis and exercise training is a strategy for management of cardiac risks in at-risk populations. Therefore, the aims of this study were to evaluate: (1) the influence of the aging process on cardiac function, hemodynamics, cardiovascular autonomic modulation, and baroreflex sensitivity in females with atherosclerosis at the onset of reproductive senescence; and (2) the impact of exercise training on age-related dysfunctions in this model. Eighteen Apolipoprotein-E knockout female mice were divided equally into young (Y), middle-aged (MA), and trained middle-aged (MAT). Echocardiographic exams were performed to verify cardiac morphology and function. Cannulation for direct recording of blood pressure and heart rate, and analysis of cardiovascular autonomic modulation, baroreflex sensitivity were performed. The MA had lower cardiac diastolic function (E'/A' ratio), and higher aortic thickness, heart rate and mean arterial pressure, lower heart rate variability and baroreflex sensitivity compared with Y. There were no differences between Y and MAT in these parameters. Positive correlation coefficients were found between aortic wall thickness with hemodynamics data. The aging process causes a series of deleterious effects such as hemodynamic overload and dysautonomia in female with atherosclerosis. Exercise training was effective in mitigating aged-related dysfunctions.

Combined Exercise Training Promotes More Benefits on Cardiovascular Autonomic Modulation in Ovariectomized Rats Than Isolated Aerobic or Resistance Training.

Introduction: Cardiovascular risk increase after ovarian deprivation has been extensively demonstrated by our research group through cardiovascular autonomic analysis. Interventions involving different types of exercises, such as resistance exercises or combined exercises (aerobic and resistance) have been widely recommended to prevent or minimize neuromuscular decline in postmenopausal women, which is aggravated by a sedentary lifestyle. Experimentally, the cardiovascular effects of resistance or combined training, as well as comparison between aerobic, resistance, and combined training, in ovariectomized animals are scarce. Purpose: In this study, we hypothesized that the combination of aerobic and resistance training may be more effective in preventing muscle mass loss, as well as improving cardiovascular autonomic modulation and baroreflex sensitivity, than aerobic or resistance training individually in ovariectomized rats. Animals and Methods: Female rats were divided into 5 groups: sedentary (C); ovariectomized (Ovx); trained ovariectomized submitted to aerobic training (OvxAT); resistance training (OvxRT); combined training (OvxCT). Exercise training lasted 8 weeks, with the combined group alternating between aerobic training and resistance training every other day. At the end of the study, glycemia and insulin tolerance were evaluated. Arterial pressure (AP) was directly recorded. Baroreflex sensitivity was assessed by heart rate response to changes in arterial pressure. Cardiovascular autonomic modulation was evaluated by spectral analysis. Results: Combined training was the only training regime that increased baroreflex sensitivity for tachycardic response and reduced all systolic blood pressure variability parameters. Furthermore, all animals submitted to exercise training on a treadmill (OvxAT and OvxCT) presented lower systolic, diastolic, and mean pressure, as well as improvements in the autonomic modulation for the heart. Conclusion: Combined training showed to be more effective than isolated aerobic and resistance training, mixing the isolated benefits of each modality. It was the only modality able to increase baroreflex sensitivity to tachycardic responses, reduce arterial pressure and all parameters of vascular sympathetic modulation.

Effects of Exercise Intensity on Cardiometabolic Parameters of Ovariectomized Obese Mice.

The aim of this study was to compare the effects of continuous-moderate vs. high-intensity interval aerobic training on cardiovascular and metabolic parameters in ovariectomized high-fat-fed mice. C57BL/6 female ovariectomized were divided into four groups (n=8): low-fat-fed sedentary (SLF); high-fat-fed sedentary (SHF); high-fat-fed moderate-intensity continuous trained (MICT-HF); and high-fat-fed high-intensity interval aerobic trained (HIIT-HF). The high-fat diet lasted 10 weeks. Ovariectomy was performed in the fourth week. The exercise training was carried out in the last four weeks of protocol. Fasting glycemia, oral glucose tolerance, arterial pressure, baroreflex sensitivity, and cardiovascular autonomic modulation were evaluated. Moderate-intensity continuous training prevented the increase in arterial pressure and promoted a reduction in HR at rest, associated with an improvement in the sympathovagal balance in MICT-HF vs. SHF. The high-intensity interval training reduced blood glucose and glucose intolerance in HIIT-HF vs. SHF and MICT-HF. In addition, it improved sympathovagal balance in HIIT-HF vs. SHF. Moderate-intensity continuous training was more effective in promoting cardiovascular benefits, while high-intensity interval training was more effective in promoting metabolic benefits.

Ovarian status modulates cardiovascular autonomic control and oxidative stress in target organs.

Studies have presented conflicting findings regarding the association between both fluctuation and deprivation of ovarian hormones and cardiovascular autonomic modulation and oxidative stress and their potential impact on resting arterial pressure (AP) and cardiovascular risk. This study aimed to assess cardiovascular autonomic modulation, baroreflex sensitivity (BRS), and oxidative stress in male rats (M) and in female rats during ovulatory (FOV) and non-ovulatory phases (FNOV) of the estrous cycle and after deprivation of ovarian hormones (FO). Direct AP was recorded, and BRS was assessed by using increasing doses of phenylephrine and sodium nitroprusside. AP and heart rate variability were assessed by spectral analysis. Oxidative stress profile was evaluated in cardiac, renal, and muscle tissues. In females, the ovulatory phase and ovarian hormone deprivation induced an increase in AP (FOV and FO ~ 9 mmHg) when compared to the non-ovulatory phase. Ovariectomy promoted increased cardiac sympathovagal balance (~ 17-37%) when compared to other groups. Both FOV and FO groups presented impaired BRS, associated with higher AP variability. In general, antioxidant capacity was higher in the FNOV than in the M group. Ovarian hormone deprivation induced a decrease in catalase activity in cardiac and renal tissues and an increase in lipid peroxidation in all tissues analyzed. Positive correlations (p < 0.05) were found between vascular sympathetic modulation and lipid peroxidation in cardiac (r = 0.60), renal (r = 0.60), and muscle (r = 0.57) tissues. In conclusion, both oscillation and deprivation of ovarian hormones play an important role in cardiovascular autonomic control and oxidative stress profile in target organs, which is reflected in AP changes.

Chronic responses of physical and imagery training on parkinson's disease / Respostas crônicas do treinamento físico e de imagética na doença de parkinson / Respuestas crónicas del entrenamiento físico y de imagética en la enfermedad de parkinson

ABSTRACT Introduction Physical and motor imagery training is known to induce positive results in the quality of life of patients with neurodegenerative diseases. However, it is not known which effects are achievable when both types of training are combined. Objective This study aimed to investigate the effects of a combination of physical and imagery training on neurotrophin levels, the perception of body dimensions and activities of daily living (ADL) in individuals with Parkinson's disease (PD). Methods Over an 8-week period, thirteen subjects underwent one hour of aerobic training in combination with twice-weekly imagery training (MIT). The following parameters were measured: brain-derived neurotrophic factor (BDNF) serum levels, level of dependence for activities of daily living (ADLs - Basic [ABDL] and Instrumental [AIDL]), perception of body dimensions and hand laterality test. Results Physical training combined with MIT increased serum BDNF levels in a non-statistically significant manner by 128.08% (88.81 ± 111.83 pg/ml versus 202.56 ± 183.43 pg/ml, p= 0.068). Delta BDNF showed a mean variation of 218.05 ± 547.55% (ES = 1.04). Perception of body dimensions and hand recognition reaction time both improved, but not in a non-statistically significant manner. ADLs (9.52% in ABDLs and 17.76% in AIDLs) improved in a statistically significant manner. Conclusion Despite the small number of subjects, study limitations, and the fact that most results were non-statistically significant, the results obtained here indicate clinical improvement associated with the neurotrophic action of BDNF on the perception of body dimensions and the functional capacity of Parkinson's disease subjects. Level of evidence II, Therapeutic studies-Investigation of treatment results.

RESUMO Introdução Sabe-se que o treinamento físico e de imagética motora induz a resultados positivos na qualidade de vida dos pacientes com doenças neurodegenerativas. Entretanto, não se sabe quais efeitos são possíveis de se obter quando ambos tipos de treinamento são combinados. Objetivo O presente estudo teve como objetivo investigar os efeitos de uma combinação de treinamento físico e de imagética sobre os níveis neurotróficos, percepção das dimensões corporais e atividades da vida diária (AVD) em indivíduos com doença de Parkinson (DP). Métodos Durante um período de oito semanas, 13 indivíduos realizaram uma hora de treinamento aeróbico em combinação com um treinamento de imagética motora (MIT) duas vezes por semana. Foram mensurados os seguintes parâmetros: níveis séricos do fator neurotrófico derivado do cérebro (BDNF), nível de dependência para atividades de vida diária (AVD - Básico [ABDL] e instrumental [AIDL]), percepção das dimensões corporais e teste de lateralidade da mão. Resultados O treinamento físico combinado ao MIT aumentou os níveis séricos de BDNF de um modo não estatisticamente significativo em 128,08% (88,81 ± 111,83 pg/ml versus 202,56 ± 183,43 pg/ml, p = 0,068). O delta BDNF apresentou uma variação média de 218,05 ± 547,55% (ES = 1,04). A percepção das dimensões corporais e o tempo de reação para o reconhecimento da mão melhoraram, porém, não de um modo significativo estatisticamente. As AVDs (9,52% nas ABDL's e 17,76% nas AIDLs) melhoraram de um modo significativo estatisticamente. Conclusão Apesar do pequeno número de indivíduos, limitações do estudo e ao fato de que a maioria dos resultados não era estatisticamente significativo, os resultados aqui obtidos indicam uma melhora clínica associada à ação neurotrófica do BDNF na percepção das dimensões corporais e na capacidade funcional de indivíduos com doença de Parkinson. Nível de evidência II, Estudos terapêuticos-Investigação dos resultados do tratamento.

RESUMEN Introducción Se sabe que el entrenamiento físico y de imagética motora induce a resultados positivos en la calidad de vida de los pacientes con enfermedades neurodegenerativas. Entretanto, no se sabe qué efectos son posibles de obtenerse cuando ambos tipos de entrenamiento son combinados. Objetivo El presente estudio tuvo como objetivo investigar los efectos de una combinación de entrenamiento físico y de imagética sobre los niveles neurotróficos, la percepción de las dimensiones corporales y las actividades de la vida diaria (AVD) en individuos con enfermedad de Parkinson (EP). Métodos Durante un período de ocho semanas, 13 individuos realizaron una hora de entrenamiento aeróbico en combinación con un entrenamiento de imagética motora (MIT) dos veces por semana. Se midieron los siguientes parámetros: niveles séricos del factor neurotrófico derivado del cerebro (BDNF), nivel de dependencia para las actividades de la vida diaria (AVD - Básico [ABDL] e Instrumental [AIDL]), percepción de las dimensiones corporales y test de lateralidad de la mano. Resultados El entrenamiento físico combinado al MIT aumentó los niveles séricos de BDNF de un modo no estadísticamente significativo en 128,08% (88,81 ± 111,83 pg/ml versus 202,56 ± 183,43 pg/ml, p = 0,068). El delta BDNF mostró una variación promedio de 218,05 ± 547,55% (ES = 1,04). La percepción de las dimensiones corporales y el tiempo de reacción para el reconocimiento de la mano mejoraron, aunque no de un modo estadísticamente significativo. Las AVD (9,52% en las ABDL y 17,76% en AIDL) mejoraron de un modo estadísticamente significativo. Conclusión A pesar del pequeño número de sujetos, limitaciones del estudio y el hecho de que la mayoría de los resultados no era estadísticamente significativos, los resultados obtenidos aquí indican una mejora clínica asociada a la acción neurotrófica del BDNF en la percepción de las dimensiones corporales y la capacidad funcional de individuos con enfermedad de Parkinson. Nivel de evidencia II, Estudios terapéuticos-Investigación de los resultados del tratamiento.

Cardiac sympathetic modulation increase after weight loss in combat sports athletes / Aumento da modulação cardíaca simpática depois de perda ponderal em atletas de combate / Aumento de la modulación cardíaca simpáticadespués de la pérdida ponderal en atletas de combate

INTRODUCTION: Although the rapid weight loss process is undertaken by combat sports athletes very often, the impact of this practice on cardiovascular health is not fully understood. OBJECTIVE: To verify the effects of the rapid weight loss process undertaken by combat sports athletes on hemodynamic parameters, cardiovascular autonomic modulation and mood state. METHODS: Eight male fighters (21.62±1.49 years, 71.25±3.54 kg, 1.74±0.03 cm) were assessed in the city of São Paulo. The subjects had 5.37±0.77 years of practice and were training 5.75±0.45 days per week, for 3.05±0.69 hours per day. The athletes were assessed on 2 occasions: 14 days before and 1 day before official weigh-in. Weight, height and bioimpedance were used for body composition analysis. Mood state was assessed using the Brums Mood Scale. Blood pressure was measured at rest with a digital meter. Cardiovascular autonomic modulation was obtained through an analysis of heart rate variability recorded for 25 minutes at rest. The Student's t-test for dependent samples was used for comparison between time points. Values of p<0.05 were considered significant. RESULTS: No differences in body composition were observed between the time points evaluated. After the weight loss strategy, increases in mood state parameters related to anger, vigor and fatigue categories were observed. Blood pressure did not change between the time points evaluated. However, an increase in heart rate associated with greater sympathetic modulation was observed after the weight loss strategy. There were no differences in autonomic modulation parameters representing parasympathetic activity. CONCLUSIONS: The study provided evidence of a higher cardiovascular risk in athletes as a result of this rapid weight loss practice, which is very concerning since combat sports athletes repeat this process several times during their lives. Level of Evidence IV; Study type: Case series

INTRODUÇÃO: Apesar de o processo de perda ponderal rápida ser realizado por atletas de esporte de combate com muita frequência, os impactos dessa prática sobre a saúde cardiovascular não estão totalmente esclarecidos. OBJETIVO: Verificar os efeitos do processo de perda ponderal rápida realizado pelos atletas de esportes de combate sobre parâmetros hemodinâmicos, modulação autonômica cardiovasculares estado de humor. MÉTODOS: Foram avaliados oito lutadores do sexo masculino (21,62 ± 1,49 anos, 71,25 ± 3,54 kg, 1,74±0,03 cm) na cidade de São Paulo. Os sujeitos tinham 5,37 ± 0,77 anos de prática, treinavam 5,75 ± 0,45 dias por semana, durante 3,05 ± 0,69 horas por dia. Os atletas foram avaliados em duas oportunidades: 14 dias e 1 dia antes da pesagem. Foram realizadas avaliações de massa corporal, altura e bioimpedância para análise da composição corporal. O estado de humor foi avaliado pela da escala de humor de Brums. A pressão arterial foi aferida em repouso com medidor digital. A modulação autonômica cardiovascular foi obtida pela análise de variabilidade da frequência cardíaca gravada durante 25 minutos em repouso. Para a comparação entre os momentos, foi utilizado teste t de Student para amostras dependentes. Os valores de p < 0,05 foram considerados significativos. RESULTADOS: Não foram observadas diferenças na composição corporal entre os momentos avaliados. Após a estratégia de perda ponderal, foram observados aumentos dos parâmetros de humor relacionados às categorias raiva, vigor e fadiga. A pressão arterial não se alterou entre os momentos avaliados. Entretanto, verificou-se aumento da frequência cardíaca associado à maior modulação simpática após a estratégia de perda ponderal. Os parâmetros de modulação autonômica representativos de atividade parassimpática não apresentaram diferenças. CONCLUSÕES: Houve maior risco cardiovascular nos atletas em decorrência dessa prática de perda ponderal rápida, o que é muito preocupante, tendo em vista que os atletas de esportes de combate repetem esse processo várias vezes durante a vida. Nível de Evidência IV; Tipo de estudo: Série de casos.

INTRODUCCIÓN: A pesar de que el proceso de pérdida ponderal rápida sea realizado por atletas de deporte de combate con mucha frecuencia, los impactos de esta práctica sobre la salud cardiovascular no están totalmente aclarados. OBJETIVO: Verificar los efectos del proceso de pérdida ponderal rápida realizado por los atletas de deportes de combate sobre parámetros hemodinámicos, modulación autonómica cardiovascular y el estado de humor. MÉTODOS: Se evaluaron 8 luchadores del sexo masculino (21,62±1,49 años, 71,25±3,54 kg, 1,74±0,03 cm) en la ciudad de São Paulo. Los sujetos tenían 5,37±0,77 años de práctica, entrenaban 5,75±0,45 días a la semana, durante 3,05±0,69 horas al día. Los atletas fueron evaluados en dos oportunidades: 14 días y 1 día antes del pesaje. Se realizaron evaluaciones de masa corporal, altura y bioimpedancia para análisis de la composición corporal. El estado de humor fue evaluado a través de la escala de humor de Brums. La presión arterial se midió en reposo con medidor digital. La modulación autonómica cardiovascular fue obtenida a través del análisis de variabilidad de la frecuencia cardíaca grabada durante 25 minutos en reposo. Para la comparación entre los momentos, se utilizó la prueba t de Student para muestras dependientes. Los valores de p <0,05 se consideraron significativos. RESULTADOS: No se observaron diferencias en la composición corporal entre los momentos evaluados. Después de la estrategia de pérdida ponderal, se observaron aumentos en los parámetros de humor relacionados con las categorías rabia, vigor y fatiga. La presión arterial no se alteró entre los momentos evaluados. Sin embargo, se observó un aumento en la frecuencia cardíaca asociado a la mayor modulación simpática después de la estrategia de pérdida ponderal. Los parámetros de modulación autonómica representativos de actividad parasimpática no presentaron diferencias. CONCLUSIONES: Hubo mayor riesgo cardiovascular en los atletas como consecuencia de esta práctica de pérdida ponderal rápida, lo que es muy preocupante, teniendo en cuenta que los atletas de deportes de combate repiten este proceso varias veces durante su vida. Nivel de Evidencia: IV. Tipo de estudio: Serie de casos.

Combined Aerobic and Resistance Exercise Training Improve Hypertension Associated With Menopause.

The prevalence of hypertension sharply increases in menopausal women. Recent studies have demonstrated that aerobic or resistance training may help control hypertension. In this study, we report that combining aerobic and resistance training may provide an effective therapeutic approach for hypertension control, attenuating inflammation and oxidative stress in ovariectomized rats. Female Wistar and spontaneous hypertensive rats (SHR) were distributed into four groups: sedentary control (C), sedentary hypertensive (HR), sedentary hypertensive ovariectomized (HR-O), and combined trained hypertensive ovariectomized (T-HR-O). Combined exercise training was performed on a motor treadmill (aerobic training) and on a ladder adapted to rats (resistance training), in alternate days for 8 weeks. Direct arterial pressure was recorded and oxidative stress and inflammation were evaluated in cardiac and renal tissue. Ovariectomy increases increased mean arterial blood pressure, sympathetic modulation, and oxidative stress in SHR. Combining aerobic and resistance training reduced mean arterial blood pressure (12% vs. HR-O), heart rate (8% vs. HR-O), vascular sympathetic modulation (40% vs. HR-O), and improved baroreflex sensitivity. Combined training reduced cardiac inflammation (TNF and IL-6) and cardiac and renal lipoperoxidation (59% and 57%, respectively vs. HR-O). It also enhanced cardiac (71%) and renal (76%) total antioxidant capacity when compared to HR-O group. In conclusion, combining aerobic and resistance training improves mean arterial blood pressure, cardiovascular autonomic control, preventing cardiac and renal oxidative stress and inflammation in an experimental hypertension model with surgical menopause induced with ovariectomy.

Impaired baroreflex sensitivity and increased systolic blood pressure variability in chronic post-ischemic stroke.

OBJECTIVES: Acute post-stroke patients present cardiovascular autonomic dysfunction, which manifests as lower heart rate variability and impaired baroreflex sensitivity. However, few studies performed to date have evaluated cardiovascular autonomic function in chronic post-stroke patients. The aim of this study was to evaluate cardiovascular autonomic modulation in chronic post-ischemic stroke patients. METHODS: The seventeen enrolled subjects were divided into a stroke group (SG, n=10, 5±1 years after stroke) and a control group (CG, n=7). Non-invasive curves for blood pressure were continuously recorded (Finometer®) for 15 minutes while the subject was in a supine position. Heart rate variability and blood pressure variability were analyzed in the time and frequency domains. RESULTS: No differences were observed in systolic and diastolic pressure and heart rate between post-stroke patients and healthy individuals. The SG group had lower indexes for heart rate variability in the time domain (standard deviation of normal to normal R-R intervals, SDNN; variance of normal to normal R-R intervals, VarNN; and root mean square differences of successive R-R intervals, RMSSD) and a lower high-frequency band for heart rate variability than was observed in the CG. Systolic blood pressure variability and the low-frequency band for systolic pressure were higher in post-stroke patients, while the alpha index was lower in the SG than in the CG. CONCLUSION: After ischemic stroke, affected patients present chronically reduced heart rate variability, impaired cardiac vagal modulation, increased systolic blood pressure variability and higher sympathetic vascular modulation along with impaired baroreflex sensitivity, which can increase the risk of cardiovascular events, despite adequate blood pressure control.

Combined aerobic and resistance exercise training attenuates cardiac dysfunctions in a model of diabetes and menopause.

The study aimed at evaluating the effects of combined aerobic and resistance exercise training on cardiac morphometry and function, oxidative stress and inflammatory parameters in diabetic ovariectomized rats. For this, female Wistar rats (10 weeks-old) were divided into 4 groups (n = 8): euglycemic (E), diabetic (streptozotocin, 50 mg/kg, iv) (D), diabetic ovariectomized (DO) and trained diabetic ovariectomized (TDO). The combined exercise training was performed on a treadmill and in a ladder adapted to rats (8 weeks, at 40-60% of maximal capacity). The left ventricle (LV) morphometry and function were evaluated by echocardiography. Oxidative stress and inflammatory markers were measured on ventricles tissue. The sedentary diabetic animals (D and DO) showed impaired systolic and diastolic functions, as well as increased cardiac overload, evaluated by myocardial performance index (MPI- D: 0.32 ± 0.05; DO: 0.39 ± 0.13 vs. E: 0.25 ± 0.07), in relation to E group. Systolic and MPI dysfunctions were exacerbated in DO when compared to D group. The DO group presented higher protein oxidation and TNF-α/IL-10 ratio than D groups. Glutathione redox ratio (GSH/GSSG) and IL-10 were decreased in both D and DO groups when compared to E group. Exercise training improved exercise capacity, systolic and diastolic functions and MPI (0.18±0.11). The TDO group showed reduced protein oxidation and TNF-α/IL-10 ratio and increased GSH/GSSG and IL-10 in relation to the DO group. These results showed that combined exercise training was able to attenuate the cardiac dysfunctions, probably by reducing inflammation and oxidative stress in an experimental model of diabetes and menopause.

Hypertension induces additional cardiometabolic impairments and attenuates aerobic exercise training adaptations in fructose-fed ovariectomized rats.

We tested whether hypertension favors the development of additional cardiometabolic changes in fructose-fed ovariectomized rats and how it affects aerobic exercise training (ET) effects. All rats received fructose in drinking water (10%) beginning at weaning, were ovariectomized at 10 weeks of age and divided into the normotensive sedentary (NFOS) and trained (NFOT) and hypertensive sedentary (HFOS) and trained (HFOT) groups. ET was performed on a treadmill. Arterial pressure (AP) was directly recorded; heart rate and AP variabilities were analyzed. Lipoperoxidation (LPO) and antioxidant enzyme levels were measured in the left ventricle. In addition to increased AP levels, when compared with the NFOS group, the hypertensive groups had resting tachycardia, a reduction of 29% in the pulse interval variance (VAR-PI), 19% in RMSSD (root mean square of successive differences, a cardiac parasympathetic index) and 53% in the α-index (spontaneous baroreflex), while the systolic AP variance (VAR-SAP) and its low-frequency band (LF-SAP) were sharply increased. ET did not alter AP levels. Even in the presence of hypertension, ET induced resting bradycardia, decreases of 33% in VAR-SAP and 49% in LF-SAP, and an increase of more than 60% in VAR-PI and the α-index. However, some of these parameters were still impaired relative to those of normotensive rats. LPO was reduced and catalase was increased in both trained groups, with no difference between the normotensive and hypertensive groups. Negative correlations were obtained between LPO and RMSSD (r=-0.60, P<0.05) and α-index (r=-0.63, P<0.05). In conclusion, hypertension augmented the dysfunctions in fructose-fed ovariectomized rats and attenuated metabolic aerobic ET benefits. These changes may be related to cardiovascular autonomic and oxidative stress alterations.

Impaired baroreflex sensitivity and increased systolic blood pressure variability in chronic post-ischemic stroke

OBJECTIVES: Acute post-stroke patients present cardiovascular autonomic dysfunction, which manifests as lower heart rate variability and impaired baroreflex sensitivity. However, few studies performed to date have evaluated cardiovascular autonomic function in chronic post-stroke patients. The aim of this study was to evaluate cardiovascular autonomic modulation in chronic post-ischemic stroke patients. METHODS: The seventeen enrolled subjects were divided into a stroke group (SG, n=10, 5±1 years after stroke) and a control group (CG, n=7). Non-invasive curves for blood pressure were continuously recorded (Finometer®) for 15 minutes while the subject was in a supine position. Heart rate variability and blood pressure variability were analyzed in the time and frequency domains. RESULTS: No differences were observed in systolic and diastolic pressure and heart rate between post-stroke patients and healthy individuals. The SG group had lower indexes for heart rate variability in the time domain (standard deviation of normal to normal R-R intervals, SDNN; variance of normal to normal R-R intervals, VarNN; and root mean square differences of successive R-R intervals, RMSSD) and a lower high-frequency band for heart rate variability than was observed in the CG. Systolic blood pressure variability and the low-frequency band for systolic pressure were higher in post-stroke patients, while the alpha index was lower in the SG than in the CG. CONCLUSION: After ischemic stroke, affected patients present chronically reduced heart rate variability, impaired cardiac vagal modulation, increased systolic blood pressure variability and higher sympathetic vascular modulation along with impaired baroreflex sensitivity, which can increase the risk of cardiovascular events, despite adequate blood pressure control.

Uma sessão de exercício resistido dinâmico não induz hipotensão pós-exercício em ratas shr / A dynamic resistance exercise session does not induce post-exercise hypotension in female shr rats / Una sesión de ejercicio resistido dinámico no induce hipotensión post-ejercicio en ratas shr hembras

RESUMO Introdução: O exercício resistido dinâmico tem sido recomendado como complemento do aeróbico em indivíduos hipertensos. No entanto, poucos estudos avaliaram os efeitos do exercício resistido nessa população, principalmente em mulheres. Objetivo: Avaliar os efeitos de uma sessão de exercício resistido dinâmico sobre a pressão arterial, a frequência cardíaca e sobre o duplo produto em ratas SHR com hipertensão espontânea. Métodos: Foram utilizadas oito ratas SHR em fase não ovulatória do ciclo estral. Dois dias depois da canulação de artéria carótida, a pressão arterial foi diretamente registrada por 20 minutos no período basal e durante 60 minutos (5 min., 15-30 min., 30-45 min. e 45-60min.) após uma sessão de exercício resistido dinâmico em escada (20%-40% da carga máxima). Resultados: Não foram observadas mudanças na pressão arterial sistólica (basal 191 ± 6,1 vs. recuperação 45-60 min. 191 ± 7,8 mmHg), diastólica (basal 157 ± 2,6 vs. recuperação 45-60 min. 156 ± 3,7 mmHg) e média (basal 174 ± 2,5 vs. recuperação 45-60 min. 173 ± 4,9 mmHg) durante os 60 minutos pós-exercício. No entanto, houve redução da frequência cardíaca (45-60 min. 330 ± 10 vs. 379 ± 15 bpm) e normalização do duplo produto (64390 ± 3529 mmHg.bpm) no período de recuperação com relação ao período basal. Conclusão: Os resultados do presente estudo demonstram que o exercício resistido dinâmico de moderada intensidade induz redução da frequência cardíaca associada à normalização do duplo produto em ratas SHR apesar de não ter sido observada hipotensão pós-exercício. Tais resultados sugerem um bom controle do risco cardiovascular depois uma sessão de exercício resistido dinâmico de moderada intensidade em pacientes hipertensos.

ABSTRACT Introduction: Dynamic resistance exercise has been recommended as an aerobic complement in hypertensive individuals. However, few studies evaluated the effects of resistance exercise in this population, especially in women. Objective: To evaluate the effects of a session of dynamic resistance exercise on blood pressure, heart rate and the double product in SHR female rats with spontaneous hypertension. Methods: We used 8 female SHR rats in the non-ovulatory phases of estrous cycle. Two days after the carotid artery cannulation, blood pressure was recorded for 20 minutes at baseline and for 60 minutes (5 min.; 15-30 min.; 30-45 min. and 45-60min.) after one session of dynamic resistance exercise in a ladder (20-40% of maximum load). Results: There were no changes in systolic blood pressure (baseline: 191±6.1 vs. recovery 45-60min., 191±7.8 mmHg), diastolic (baseline: 157±2.6 vs. recovery 45-60min., 156±3.7 mmHg) and mean blood pressure (baseline: 174±2.5 vs. recovery 45-60min., 173±4.9 mmHg) during the 60 minutes post-exercise. However, there was a reduction in heart rate (45-60min. 330±10 vs. 379±15 bpm) and normalization of the double product (64390±3529 mmHg.bpm) in the recovery period compared to the baseline. Conclusion: The results of the present study demonstrated that moderate-intensity dynamic resistance exercise induces reduced heart rate associated with normalization of the double product in female SHR rats, despite the absence of post-exercise hypotension. These results suggest good control of cardiovascular risk after a dynamic resistance exercise of moderate intensity in hypertensive patients.

RESUMEN Introducción: El ejercicio resistido dinámico ha sido recomendado como complemento del aeróbico en individuos hipertensos. Sin embargo, pocos estudios han evaluado los efectos del ejercicio resistido en esa población, principalmente en mujeres. Objetivo: Evaluar los efectos de una sesión de ejercicio resistido dinámico sobre la presión arterial, la frecuencia cardiaca y sobre el doble producto en ratas SHR hembras con hipertensión espontánea. Métodos: Se utilizaron ocho ratas SHR hembras en fase no ovulatoria del ciclo estral. Dos días después de la canulación de la arteria carótida, la presión arterial fue registrada directamente durante 20 minutos en el período basal y durante 60 minutos (5 min., 15-30 min., 30-45 min. y 45-60 min.) después de una sesión de ejercicio resistido dinámico en escalera (20%-40% de la carga máxima). Resultados: No se observaron cambios en la presión arterial sistólica (basal 191 ± 6,1 vs. recuperación 45-60 min, 191 ± 7,8 mmHg), diastólica (basal 157 ± 2,6 vs. recuperación 45-60 min., 156 ± 3,7 mmHg) y media (basal 174 ±2 ,5 vs. recuperación 45-60 min, 173 ± 4,9 mmHg) durante los 60 minutos posteriores al ejercicio. Sin embargo, hubo reducción de la frecuencia cardiaca (45-60 min. 330 ± 10 vs. 379 ± 15 bpm) y normalización del doble producto (64390 ± 3529 mmHg.bpm) en el período de recuperación con relación al período basal. Conclusión: Los resultados del presente estudio demuestran que el ejercicio resistido dinámico de intensidad moderada induce reducción de la frecuencia cardiaca asociada a la normalización del doble producto en ratas SHR hembras, a pesar de no haber sido observada hipotensión post-ejercicio. Estos resultados indican un buen control del riesgo cardiovascular después de una sesión de ejercicio resistido dinámico de intensidad moderada en pacientes hipertensos.

The importance of animal studies in exercise science

Abstract The validity and relevance of research with animals for the development of knowledge in Exercise Science have for long been discussed. Given the complexity of the biological systems, the use of animal models offers a significant contribution to uncover new findings about acute and chronic effects of exercise, particularly when these studies in humans have limitations and ethical implications. There have been notable findings using experimental animals either in basic sciences or in clinical studies involving physiology, pharmacology, genetic, biochemistry, urology, endocrinology and cancer. This article presents a brief review of scientific research using animal models with a focus on exercise training as an effective tool for the prophylaxis and treatment of different pathological processes, which are the basis of many concepts taught and used in undergraduate courses and graduate programs, as well as in new researches showed in scientific conference meetings in numerous areas of science.(AU)

Aerobic exercise training promotes additional cardiac benefits better than resistance exercise training in postmenopausal rats with diabetes.

OBJECTIVE: The aim of this study was to evaluate the effects of aerobic exercise training or resistance exercise training on cardiac morphometric, functional, and oxidative stress parameters in rats with ovarian hormone deprivation and diabetes. METHODS: Female Wistar rats (200-220 g) were divided into a sham-operated group (euglycemic sham-operated sedentary [ES]; n = 8) and three ovariectomized (bilateral removal of ovaries) and diabetic (streptozotocin 50 mg/kg IV) groups as follows: diabetic ovariectomized sedentary (DOS; n = 8), diabetic ovariectomized undergoing aerobic exercise training (DOTA; n = 8), and diabetic ovariectomized undergoing resistance exercise training (DOTR; n = 8). After 8 weeks of resistance (ladder) or aerobic (treadmill) exercise training, left ventricle function and morphometry were evaluated by echocardiography, whereas oxidative stress was evaluated at the left ventricle. RESULTS: The DOS group presented with increased left ventricle cavity in diastole and relative wall thickness (RWT), and these changes were attenuated in both DOTA and DOTR groups. Systolic and diastolic function was impaired in the DOS group compared with the ES group, and only the DOTA group was able to reverse this dysfunction. Lipoperoxidation and glutathione redox balance were improved in both trained groups compared with the DOS group. Glutathione peroxidase and superoxide dismutase were higher in the DOTA group than in the other studied groups. Correlations were observed between lipoperoxidation and left ventricle cavity in diastole (r = 0.55), between redox balance and RWT (r = 0.62), and between lipoperoxidation and RWT (r = -0.60). CONCLUSIONS: Aerobic exercise training and resistance exercise training promote attenuation of cardiac morphometric dysfunction associated with a reduction in oxidative stress in an experimental model of diabetes and menopause. However, only dynamic aerobic exercise training is able to attenuate systolic and diastolic dysfunction under this condition.

Cardiovascular autonomic dysfunction and oxidative stress induced by fructose overload in an experimental model of hypertension and menopause.

BACKGROUND: Metabolic syndrome is characterized by the association of 3 or more risk factors, including: abdominal obesity associated with an excess of abdominal fat, insulin resistance, type 2 diabetes, dyslipidemia and hypertension. Moreover, the prevalence of hypertension and metabolic dysfunctions sharply increases after the menopause. However, the mechanisms involved in these changes are not well understood. Thus, the aim of this study was to assess the effects of fructose overload on cardiovascular autonomic modulation, inflammation and cardiac oxidative stress in an experimental model of hypertension and menopause. METHODS: Female SHR rats were divided into (n = 8/group): hypertensive (H), hypertensive ovariectomized (HO) and hypertensive ovariectomized undergoing fructose overload (100 g/L in drinking water) (FHO). Arterial pressure (AP) signals were directly recorded. Cardiac autonomic modulation was evaluated by spectral analysis. Oxidative stress was evaluated in cardiac tissue. RESULTS: AP was higher in the FHO group when compared to the other groups. Fructose overload promoted an increase in body and fat weight, triglyceride concentration and a reduction in insulin sensitivity. IL-10 was reduced in the FHO group when compared to the H group. TNF-α was higher in the FHO when compared to all other groups. Lipoperoxidation was higher and glutathione redox balance was reduced in the FHO group when compared to other groups, an indication of increased oxidative stress. A negative correlation was found between IL-10 and adipose tissue. CONCLUSION: Fructose overload promoted an impairment in cardiac autonomic modulation associated with inflammation and oxidative stress in hypertensive rats undergoing ovarian hormone deprivation.

Influência dos hormônios sexuais no consumo de oxigênio de ratos / Influence of sexual hormones on oxygen consumption in rats / Influencia de las hormonas sexuales en el consumo de oxígeno en ratas

Introdução: Achados da literatura sugerem que oscilações dos hormônios sexuais femininos podem alterar o consumo máximo de oxigênio (VO2max). Objetivo: Comparar o VO2max entre ratos machos (M, n=8), fêmeas nas fases ovulatórias (OV, n=8) ou não-ovulatórias (NOV, n=8) do ciclo estral e ooforectomizadas (OS, n=8). Métodos: A avaliação do consumo de oxigênio foi realizada em esteira rolante com caixa metabólica acoplada. Resultados: Em repouso, o VO2 foi semelhante entre os grupos estudados. O grupo M apresentou maior VO2max em relação ao grupo NOV, mas valores semelhantes ao do grupo OV. O VO2max foi menor no grupo ooforectomizado (OS: 62±3 ml.kg-1.min-1) quando comparado aos demais grupos (M: 92±2; NOV: 77±4; OV: 87±3 ml.kg-1.min-1). Conclusões: Esses achados evidenciam que a variação hormonal decorrente das diferentes fases do ciclo estral e da privação dos hormônios ovarianos pode induzir alterações no consumo máximo de oxigênio em ratos. .

Introduction: Literature findings suggest that fluctuations of female sex hormones may change the maximum oxygen consumption (VO2 max). Objective: To compare the VO2 max among male rats (M, n = 8), female rats on ovulatory (OV, n=8) or non-ovulatory (NOV, n=8) phases of the estrous cycle and ovariectomized (OS, n=8). Methods: The evaluation of oxygen consumption was performed on a treadmill coupled with metabolic box. Results: At rest VO2 was similar among groups. The M group had a higher VO2 max compared to the NOV group, however showed similar values when compared to OV group. The VO2 max was lower in the ovariectomized group (OS: 62±3 ml.kg-1.min-1) compared to other groups (M: 92±2; NOV: 77 ± 4; OV: 87 ± 3 ml.kg-1.min-1). Conclusions: These findings suggest that hormonal variation resulting from different phases of the estrous cycle and ovarian hormone deprivation can induce changes in maximal oxygen uptake in rats. .

Introducción: Hallazgos de la literatura sugieren que oscilaciones de las hormonas sexuales femeninas pueden alterar el consumo máximo de oxígeno (VO2max). Objetivo: Comparar el VO2max entre ratas machos (M, n=8), hembras en las fases ovulatorias (OV, n=8) o no ovulatorias (NOV, n=8) del ciclo estral y ooforectomizadas (OS, n=8). Métodos: La evaluación del consumo de oxígeno fue realizada en cinta rodante con caja metabólica acoplada. Resultados: En reposo, el VO2 fue semejante entre los grupos estudiados. El grupo M presentó mayor VO2max en relación al grupo NOV, pero valores semejantes a los del grupo OV. El VO2max fue menor en el grupo ooforectomizado (OS: 62±3 ml.kg-1.min-1) cuando comparado a los demás grupos (MS: 92±2; NOV: 77±4; OV: 87±3 ml.kg-1.min-1). Conclusiones: Esos hallazgos evidencian que la variación hormonal proveniente de las diferentes fases del ciclo estral y de la privación de las hormonas ováricas puede inducir alteraciones en el consumo máximo de oxígeno en ratas. .

Hemodynamic effect of laser therapy in spontaneously hypertensive rats.

Systemic arterial hypertension (SAH) is considered to be the greatest risk factor for the development of neuro-cardiovascular pathologies, thus constituting a severe Public Health issue in the world. The Low-Level Laser Therapy (LLLT), or laser therapy, activates components of the cellular structure, therefore converting luminous energy into photochemical energy and leading to biophysical and biochemical reactions in the mitochondrial respiratory chain. The LLLT promotes cellular and tissue photobiomodulation by means of changes in metabolism, leading to molecular, cellular and systemic changes. The objective of this study was to analyze the action of low-level laser in the hemodynamic modulation of spontaneously hypertensive rats, in the long term. Animals (n = 16) were randomly divided into the Laser Group (n = 8), which received three weekly LLLT irradiations for seven weeks, and into the Sham Group (n = 8), which received three weekly simulations of laser for seven weeks, accounting for 21 applications in each group. After seven weeks, animals were cannulated by the implantation of a catheter in the left carotid artery. On the following day, the systemic arterial pressure was recorded. The Laser Group showed reduced levels of mean blood pressure, with statistically significant reduction (169 ± 4 mmHg* vs. 182 ± 4 mmHg from the Sham Group) and reduced levels of diastolic pressure (143 ± 4 mmHg* vs. 157 ± 3 mmHg from the Sham Group), revealing a 13 and 14 mmHg decrease, respectively. Besides, there was a concomitant important decline in heart rate (312 ± 14 bpm vs. 361 ± 13 bpm from the Sham Group). Therefore, laser therapy was able to produce hemodynamic changes, thus reducing pressure levels in spontaneously hypertensive rats.

Fisiologia do Exercício para alunos de graduação: uso de estratégias de ensino baseadas na metodologia dialética / Exercise Physiology for undergraduates: the use of teaching strategies basead on the dialectical method

A metodologia dialética propõe um ensino de dupla mão (professor-aluno) que provoque a aprendizagem por meio de tarefas contínuas dos sujeitos. Para isso, o professor assume o papel de mediador e dirige as diferentes atividades. Nesse contexto, a Fisiologia do Exercício é uma disciplina academicamente orientada que está inserida em um ambiente dinâmico, e a utilização de estratégias de ensino se faz necessária para otimizar a apropriação do conhecimento de forma ativa, além de contribuir para a maior autonomia dos estudantes universitários. Portanto, o objetivo do presente estudo foi o de utilizar diferentes estratégias de ensinagem por meio de atividades propostas aos alunos na disciplina de Fisiologia da Atividade Motora I da Escola de Educação Física e Esporte da Universidade de São Paulo e correlacionar o desempenho do aluno com a sua participação nessas atividades propostas. Nossos principais achados demonstram correlações significativas e positivas entre a presença nas aulas e o desempenho nas avaliações (p < 0,0001; r = 0,84), bem como entre a realização das atividades propostas e o desempenho nas avaliações (p < 0,0001; r = 0,69). Em conjunto, esses dados sugerem que a utilização de diferentes estratégias de ensinagem baseadas na metodologia dialética com a ativa participação dos alunos é essencial para um bom rendimento acadêmico, sendo altamente recomendada para o ensino da Fisiologia do Exercício...

The dialectic method proposes a two-way teaching (teacher-student) that causes learning through ongoing task of the subjects. For this, the teacher assumes the role of mediator and directs several activities. In line with the above, Exercise Physiology is an academically oriented discipline undergoing in a dynamic environment, and the use of different teaching strategies is needed to optimize the appropriation of knowledge in an active way and contribute to the greater autonomy of university students. Therefore, the aim of this study was apply different strategies in the course entitled "Physiology of the Motor Activity I" at School of Physical Education and Sport of University of Sao Paulo and assess a correlation between students participation and students performance. We used teaching strategies such as exposition and dialogue classes, practical classes, conversations with experts, directed study, study of scientific texts, concept mapping, case study and study of the environment in order to optimize the appropriation of the concepts of exercise physiology with emphasis on neuromuscular and cardiovascular physiology exercise. Our main findings show significant and positive correlations between the presence in classes and the performance evaluations (p < 0.0001, r = 0.84) as well as between the tasks proposed and the performance evaluations (p < 0.0001; r = 0.69). Altogether, these data suggest that using different teaching strategies based on the dialectic method associated with the participation of students is essential for a good academic performance in Exercise Physiology...

Acute exercise adjustments of cardiovascular autonomic control in diabetic rats.

INTRODUCTION: We evaluated the role of cardiovascular autonomic changes in hemodynamics at rest and in response to exercise in streptozotocin-induced diabetic rats. METHODS: Male Wistar rats were divided into nondiabetic (ND, n = 8) and diabetic (D, n = 8) groups. Arterial pressure signals were recorded in the basal state and after atropine or propranolol injections at rest, during exercise and during recovery. RESULTS: At rest, vagal tonus was reduced in D (37 ± 3 bpm) in comparison with the ND group (61 ± 9 bpm). Heart rate during exercise was lower in D in relation to ND rats associated with reduced vagal withdrawal in the D group. The D rats had an increase in vagal tonus in the recovery period (49 ± 6 bpm). CONCLUSIONS: Exercise-induced hemodynamic adjustment impairment in diabetic rats was associated with reduced cardiac vagal control. The vagal dysfunction was attenuated after aerobic exercise, reinforcing the positive role of this approach in the management of cardiovascular risk in diabetics.

Cardiometabolic benefits of exercise training in an experimental model of metabolic syndrome and menopause.

OBJECTIVE: The aim of this study was to investigate the cardiometabolic effects of exercise training in ovariectomized hypertensive rats both submitted and not submitted to fructose overload. METHODS: Spontaneously hypertensive ovariectomized rats were divided into sedentary and trained (THO) groups submitted to normal chow and sedentary and trained groups submitted to fructose overload (100 g/L in drinking water for 19 wk). Exercise training was performed on a treadmill (8 wk). Arterial pressure (AP) was directly recorded. Cardiovascular autonomic control was evaluated through pharmacological blockade (atropine and propranolol) and in the time and frequency domains by spectral analysis. RESULTS: The THO group presented reduced AP (approximately 16 mm Hg) and enhanced cardiac vagal tonus (approximately 49%) and baroreflex sensitivity (approximately 43%) compared with the sedentary hypertensive ovariectomized group. Exercise training attenuated metabolic impairment, resting tachycardia, cardiac and vascular sympathetic increases, and baroreflex sensitivity decrease induced by fructose overload in hypertensive rats. However, the trained hypertensive ovariectomized group submitted to fructose overload presented higher AP (approximately 32 mm Hg), associated with baroreflex sensitivity (approximately 69%) and parasympathetic dysfunctions compared with the THO group. CONCLUSIONS: These data suggest that the metabolic disorders in hypertensive rats after ovarian hormone deprivation could blunt and/or attenuate some exercise training benefits.