Neuromuscular electrical stimulation changes glucose, but not its variability in type 2 diabetes: a randomized clinical trial.

Neuromuscular electrical stimulation (NMES) can be an alternative to conventional exercising. This randomized clinical trial evaluated the effect of NMES in type 2 diabetes patients. Twenty-eight individuals with type 2 diabetes were assigned to NMES (n=14) or NMES-placebo (n=14) applied to knee extensor muscles for 60 minutes. Glucose variability, microvascular function and endothelial function were evaluated through continuous glucose monitoring system, near infrared spectroscopy and flow-mediated dilatation, respectively. Glucose levels (mg/dl) decreased 2h (184 ± 11 vs 223 ±15), 3h (179 ± 12 vs 219 ±14) and 4h (177 ± 12 vs 212 ±12) after NMES, in comparison to NMES-placebo. No differences in glucose variability were found: coefficient of variation (%) at 0-6h (11.4±1.3 vs 11.4±1.2), 6-12h (9.8±1.0 vs 11.6±1.6), 12-18h (15.5±2.0 vs 11.4±2.1), 18-24h (12.8±2.3 vs 10.0±1.6); standard deviation (mg/dl) at 0-6h (21.6±2 vs 24.6±3.5), 6-12h (19.5±1.8 vs 20.3±2.8), 12-18h (29.9±3.5 vs 21.3±2.8),18-24h (22.8±4.1 vs 16.6±2.0) and mean amplitude of glycemic excursions (mg/dl) 54.9±25.0 vs 70.3±35.7. Endothelial and microvascular functions did not change. In conclusion, one acute NMES session was strong enough to trigger glucose reduction in individuals with type 2 DM, but it failed to induce any significant change in glucose variability, endothelial and microvascular functions.

Home-based inspiratory muscle training in pediatric patients after kidney transplantation: a randomized clinical trial.

BACKGROUND: Chronic kidney disease (CKD) represents the irreversible stages of renal failure and is a growing worldwide public health issue associated with increases in morbidity, mortality, and decreased quality of life. Kidney transplantation is considered one of the best treatment options in this population. However, even after surgery, respiratory muscle strength is below normal values, and inspiratory muscle training (IMT) improves respiratory muscle function, strength, and endurance. This study aimed to evaluate the effects of IMT regarding respiratory muscle strength, functional capacity, and pulmonary function in pediatric kidney transplant recipients with CKD, and secondarily, to assess the biochemical profile of patients after intervention. METHODS: This is a randomized, double-blind, placebo-controlled trial. Patients were randomized into two groups, intervention (IG) and control (CG) and performed IMT home-based training for 6 weeks. In the IG, the load was adjusted to 40% of the maximal inspiratory pressure and in the CG was adjusted to a minimum placebo load (9 cm H2O). RESULTS: Thirty-one patients were randomly allocated to the intervention (n = 16) or control (n = 15) groups. There were no differences at baseline between groups. Increase of 35% in the maximal inspiratory pressure predicted and 26% in the maximal expiratory pressure predicted in the IG were found, compared with 5 and 4% in the CG. There was an increase in hemoglobin and hematocrit values in the IG. CONCLUSIONS: Home-based IMT provides a significant increase in respiratory muscle strength, without changes in functional capacity and pulmonary function. Benefits regarding biochemical markers (hemoglobin and hematocrit) were also observed.

Moderate-to-high intensity inspiratory muscle training improves the effects of combined training on exercise capacity in patients after coronary artery bypass graft surgery: A randomized clinical trial.

BACKGROUND: The effects of adding moderate-to-high intensity inspiratory muscle training (IMT) to short-term aerobic and resistance exercise (combined training [CT]), after coronary artery bypass grafting (CABG) are not established. This study aimed to determine the effects of moderate-to-high intensity IMT + CT on exercise capacity, respiratory muscle strength, inspiratory muscle endurance, quality of life (QoL), and laboratory biomarkers in patients after CABG who were participants of a phase II cardiac rehabilitation program. METHODS: Twenty-four patients were randomly assigned to either the IMT + CT group (n = 12), who performed moderate-to-high intensity IMT with CT or the sham-IMT + CT group (n = 12). Patients completed two sessions per week for 12 weeks. Each patient underwent a cardiopulmonary exercise test, six-minute walk test (6MWT), respiratory muscle strength and endurance evaluation, QoL questionnaire, and serum advanced oxidation protein products, ferric reducing antioxidant power [FRAP], nitrate/nitrate, and high-sensitivity C-reactive protein, before and after the 12-week intervention. RESULTS: The IMT + CT group showed significantly greater improvements in peak oxygen uptake (1.3 mL∙kg-1∙min-1; 95% confidence interval [95% CI], 0.5 to 2.2), distance covered during the 6MWT (78.8 m; 95% CI, 28.1 to 129.5), maximal inspiratory pressure (23.0 cmH2O; 95% CI, 9.3 to 36.7), QoL (-15.1 points; 95% CI, -26.9 to -3.3), and FRAP (83.7 µmol/L; 95% CI, 20.2 to 147.1) compared to the sham-IMT + CT group as a result of the intervention. CONCLUSIONS: Short-term moderate-to-high intensity IMT with CT provided additional benefits in exercise capacity, inspiratory muscle strength, QoL, and antioxidant profile in patients after CABG. Trial Registration clinicaltrials.gov Identifier: NCT02885077.

Aerobic training reduces oxidative stress in skeletal muscle of rats exposed to air pollution and supplemented with chromium picolinate.

OBJECTIVE: The purpose of this study was to investigate the effects of chromium picolinate (CrPic) supplementation associated with aerobic exercise using measures of oxidative stress in rats exposed to air pollution. METHODS: Sixty-one male Wistar rats were divided into eight groups: residual oil fly ash (ROFA) exposure and sedentary (ROFA-SED); ROFA exposure, sedentary and supplemented (ROFA-SED-CrPic); ROFA exposure and trained (ROFA-AT); ROFA exposure, supplemented and trained (ROFA-AT-CrPic); sedentary (Sal-SED); sedentary and supplemented (Sal-SED-CrPic); trained (Sal-AT); and supplemented and trained (Sal-AT-CrPic). Rats exposed to ROFA (air pollution) received 50 µg of ROFA daily via intranasal instillation. Supplemented rats received CrPic (1 mg/kg/day) daily by oral gavage. Exercise training was performed on a rat treadmill (5×/week). Oxidative parameters were evaluated at the end of protocols. RESULTS: Trained groups demonstrated lower gain of body mass (P < .001) and increased exercise tolerance (P < .0001). In the gastrocnemius, trained groups demonstrated increased SOD activity (P < .0001) and decrease levels of TBARS (P = .0014), although CAT activity did not differ among groups (P = .4487). CONCLUSION: Air pollution exposure did not lead to alterations in oxidative markers in lungs and heart, and exercise training was responsible for decreasing oxidative stress of the gastrocnemius.

Effects of l-arginine supplementation associated with continuous or interval aerobic training on chronic heart failure rats.

OBJECTIVE: Chronic heart failure (CHF) is related with exercise intolerance and impaired nitric oxide (NO) production, which can lead to several functional capacity alterations. Considering the possible superiority of aerobic interval training compared to continuous training and the capacity of l-arginine to restore the NO pathway, the aim of the present study was to investigate whether these treatments are beneficial to exercise capacity, muscle mass preservation and hemodynamic, inflammatory and oxidative stress parameters in CHF rats. METHODS: Thirty-eight male Wistar rats post 6weeks of myocardial infarction (MI) surgery were randomly assigned into 6 CHF groups: sedentary (SED, n=6); SED+Arg (n=7); ACT (n=8); ACT+Arg (n=5); AIT (n=7); AIT+Arg (n=5). Exercise test capacity (ETC) was performed pre and post 8weeks of intervention. Supplemented rats received Arg (1g/kg) by oral gavage (7×/week). Exercise training was performed on a rat treadmill (5×/week). Hemodynamic variables, tissue collection, congestion, inflammatory cytokines, and oxidative parameters were evaluated at the end of protocols. RESULTS: All trained groups showed a superior exercise capacity compared to SED groups on the post-intervention test (p<0.0001). Pulmonary congestion was attenuated in AIT and AIT+Arg compared with the SED group (p<0.05). Left ventricular end-diastolic pressure (LVEDP) was lower in ACT+Arg, AIT, and AIT+Arg groups than SED group (p<0.05). Association of AIT with Arg supplementation was able to improve hemodynamic responses (left ventricular systolic pressure (LVSP), systolic blood pressure (SBP), +dP/dtmax, and -dP/dtmax (p<0.05), likewise, decrease muscular and renal lipid peroxidation and tumor necrosis factor (TNF)-α, and increase interleukin (IL)-10/TNF-α plasmatic levels (p<0.01). Groups that associated aerobic exercise with Arg supplementation (ACT+Arg and AIT+Arg) revealed higher gastrocnemius mass compared to the SED group (p<0.01). CONCLUSIONS: Both aerobic training protocols were capable to improve aerobic capacity, and the association with Arg supplementation was important to attenuate muscle loss. Moreover, interval training associated with Arg supplementation elicits greater improvements in hemodynamic parameters, contributing to reduction in pulmonary congestion, and demonstrated particular responses in the inflammatory profile and in the antioxidant status.

Respiratory Muscle Training Improves Diaphragm Citrate Synthase Activity and Hemodynamic Function in Rats with Heart Failure.

INTRODUCTION:: Enhanced respiratory muscle strength in patients with heart failure positively alters the clinical trajectory of heart failure. In an experimental model, respiratory muscle training in rats with heart failure has been shown to improve cardiopulmonary function through mechanisms yet to be entirely elucidated. OBJECTIVE:: The present report aimed to evaluate the respiratory muscle training effects in diaphragm citrate synthase activity and hemodynamic function in rats with heart failure. METHODS:: Wistar rats were divided into four experimental groups: sedentary sham (Sed-Sham, n=8), trained sham (RMT-Sham, n=8), sedentary heart failure (Sed-HF, n=7) and trained heart failure (RMT-HF, n=7). The animals were submitted to a RMT protocol performed 30 minutes a day, 5 days/week, for 6 weeks. RESULTS:: In rats with heart failure, respiratory muscle training decreased pulmonary congestion and right ventricular hypertrophy. Deleterious alterations in left ventricular pressures, as well as left ventricular contractility and relaxation, were assuaged by respiratory muscle training in heart failure rats. Citrate synthase activity, which was significantly reduced in heart failure rats, was preserved by respiratory muscle training. Additionally, a negative correlation was found between citrate synthase and left ventricular end diastolic pressure and positive correlation was found between citrate synthase and left ventricular systolic pressure. CONCLUSION:: Respiratory muscle training produces beneficial adaptations in the diaphragmatic musculature, which is linked to improvements in left ventricular hemodynamics and blood pressure in heart failure rats. The RMT-induced improvements in cardiac architecture and the oxidative capacity of the diaphragm may improve the clinical trajectory of patients with heart failure.

Respiratory muscle training improves diaphragm citrate synthase activity and hemodynamic function in rats with heart failure

Abstract INTRODUCTION: Enhanced respiratory muscle strength in patients with heart failure positively alters the clinical trajectory of heart failure. In an experimental model, respiratory muscle training in rats with heart failure has been shown to improve cardiopulmonary function through mechanisms yet to be entirely elucidated. OBJECTIVE: The present report aimed to evaluate the respiratory muscle training effects in diaphragm citrate synthase activity and hemodynamic function in rats with heart failure. METHODS: Wistar rats were divided into four experimental groups: sedentary sham (Sed-Sham, n=8), trained sham (RMT-Sham, n=8), sedentary heart failure (Sed-HF, n=7) and trained heart failure (RMT-HF, n=7). The animals were submitted to a RMT protocol performed 30 minutes a day, 5 days/week, for 6 weeks. RESULTS: In rats with heart failure, respiratory muscle training decreased pulmonary congestion and right ventricular hypertrophy. Deleterious alterations in left ventricular pressures, as well as left ventricular contractility and relaxation, were assuaged by respiratory muscle training in heart failure rats. Citrate synthase activity, which was significantly reduced in heart failure rats, was preserved by respiratory muscle training. Additionally, a negative correlation was found between citrate synthase and left ventricular end diastolic pressure and positive correlation was found between citrate synthase and left ventricular systolic pressure. CONCLUSION: Respiratory muscle training produces beneficial adaptations in the diaphragmatic musculature, which is linked to improvements in left ventricular hemodynamics and blood pressure in heart failure rats. The RMT-induced improvements in cardiac architecture and the oxidative capacity of the diaphragm may improve the clinical trajectory of patients with heart failure.

Maximal oxygen uptake and exercise tolerance are improved in rats with heart failure subjected to low-level laser therapy associated with resistance training.

Exercise tolerance and maximal oxygen uptake (VO2max) are reduced in heart failure (HF). The influence of combined resistance training (RT) and low-level laser therapy (LLLT) on exercise tolerance and VO2max in HF has not yet been explored. The aim of this study was to evaluate the influence of combined RT and LLLT on VO2max and exercise tolerance in rats with HF induced by myocardial infarction (MI). Rats were allocated to sedentary sham (Sed-Sham, n = 12), sedentary heart failure (Sed-HF, n = 9), RT heart failure (RT-HF, n = 7) and RT associated with LLLT heart failure (RT + LLLT-HF, n = 7) groups. After MI or sham surgery, rats underwent a RT and LLLT protocol (applied immediately after RT) for 8 weeks. VO2max and exercise tolerance were evaluated at the end of protocol. HF rats subjected to LLLT combined with RT showed higher VO2basal (41 %), VO2max (40 %), VO2reserve (39 %), run distance (46 %), time to exhaustion (30 %) and maximal velocity (22 %) compared with HF rats that underwent RT alone. LLLT associated with RT improved oxygen uptake and exercise tolerance compared with RT alone in HF rats.

Exercise during pregnancy decreases doxorubicin-induced cardiotoxic effects on neonatal hearts.

Cancer treatment with Doxorubicin (DOX) is limited due its dose-dependent cardiotoxicity, mainly related to the oxidative stress production. In experimental models of DOX treatment exercise can be used as a beneficial adjuvant therapy. This work aimed to investigate the effects of exercise during pregnancy on DOX-induced cardiotoxicity in cardiomyocytes of progeny, examining the possible intergenerational cardioprotective effects of maternal exercise. For this purpose pregnant rats were divided in control and exercise groups and pre-treated during gestational days. Hearts of newborns were used to obtain a culture of cardiomyocytes to be treated with DOX for analyses of cell viability, apoptosis and necrosis; ROS production; DNA damage; SOD and CAT activities; and Sirt6 protein expression. The results showed that exercise during pregnancy induced an increase in the viability of neonatal cardiomyocytes and a decrease in DOX-induced apoptotic and necrotic death which were correlated to the decrease in ROS production and an increase in antioxidant defenses. Exercise also protected neonatal cardiomyocytes from DOX-induced DNA damage, demonstrating a reduction in the oxidative DNA breaks. Likewise, exercise induced an increase in expression of Sirt6 in neonatal cardiomyocytes. Therefore, these results demonstrate for the first time that exercise performed by mothers protects the neonatal heart against DOX-induced toxicity. Our data demonstrate the intergenerational effect of exercise in cardiomyocytes of progeny, where the modulation of oxidative stress through antioxidant enzymes, and DNA integrity via Sirt6, were induced due to exercise in mothers, increasing the resistance of the neonatal heart against DOX toxicity.

Inspiratory muscle training in patients with diabetic autonomic neuropathy: a randomized clinical trial.

AIMS AND METHODS: We evaluated the effects of an 8-week inspiratory muscle training (IMT, n = 5) or placebo IMT (P-IMT, n = 5) on maximal respiratory pressures, pulmonary function, functional capacity, and cardiac autonomic control in patients with type 2 diabetes and diabetic autonomic neuropathy (DAN). RESULTS AND CONCLUSIONS: The IMT group had a greater increase in maximum inspiratory pressure as compared to P-IMT (p < 0.05). The IMT improved inspiratory muscle strength in patients with DAN.

Inspiratory muscle training reduces blood pressure and sympathetic activity in hypertensive patients: a randomized controlled trial.

BACKGROUND: Autonomic imbalance, characterized by sympathetic hyperactivity and diminished vagal tone, is a known mechanism for essential hypertension. Inspiratory muscle training (IMT) demonstrates beneficial outcomes in a number of cardiovascular populations, which may potentially extend to patients with hypertension. The aim of this study was to further elucidate the effects of IMT on blood pressure and autonomic cardiovascular control in patients with essential hypertension. METHODS: Thirteen patients with hypertension were randomly assigned to an eight-week IMT program (6 patients) or to a placebo-IMT (P-IMT, 7 patients) protocol. We recorded RR interval for posterior analysis of heart rate variability and blood pressure, by ambulatory blood pressure monitoring (ABPM), before and after the program. RESULTS: There was a significant increase in inspiratory muscle strength in the IMT group (82.7 ± 28.8 vs 121.5 ± 21.8 cmH2O, P<0.001), which was not demonstrated by P-IMT (93.3 ± 25.3 vs 106.1 ± 25.3 cmH2O, P>0.05). There was also a reduction in 24-hour measurement of systolic (133.2 ± 9.9 vs 125.2 ± 13.0 mm Hg, P=0.02) and diastolic (80.7 ± 12.3 vs 75.2 ± 1.0 mm Hg, P=0.02) blood pressure, as well as in daytime systolic (136.8 ± 12.2 vs 127.6 ± 14.2 mm Hg, P=0.008) and diastolic (83.3 ± 13.1 vs. 77.2 ± 12.2 mm Hg, P =0.01) blood pressure in the IMT group. In relation to autonomic cardiovascular control, we found increased parasympathetic modulation (HF: 75.5 ± 14.6 vs. 84.74 ± 7.55 n.u, P=0.028) and reduced sympathetic modulation (LF: 34.67 ± 20.38 vs. 12.81 ± 6.68 n.u; P=0.005). Moreover, there was reduction of cardiac sympathetic discharge (fLF) in IMT group (P=0.01). CONCLUSIONS: IMT demonstrates beneficial effects on systolic and diastolic blood pressure as well as autonomic cardiovascular control in hypertensive patients.