Weight loss associated with low-energy diets with different glycaemic loads does not improve arterial stiffness: a randomised clinical trial.

We evaluated the effects of two low-energy diets with different glycaemic loads on arterial stiffness in adults with excess weight. This was a 45-day parallel-group, randomised clinical trial including seventy-five participants (20-59 years; BMI 32 kg/m2). They were assigned to two similar low-energy diets (reduction of ∼750 kcal.d-1) with macronutrient composition (55 % carbohydrates, 20 % proteins and 25 % lipids) but different glycaemic loads: high-glycaemic load (HGL 171 g.d-1; n 36) or low-glycaemic load (LGL 67 g.d-1; n 39). We evaluated: arterial stiffness (pulse wave velocity, PWV); augmentation index (AIx@75); reflection coefficient; fasting blood glucose; fasting lipid profile; blood pressure and body composition. We found no improvements in PWV (P = 0·690) and AIx@75 (P = 0·083) in both diet groups, but there was a decrease in the reflection coefficient in the LGL group (P = 0·003) compared with baseline. The LGL diet group showed reductions in body weight (Δ -4·9 kg; P = 0·001), BMI (Δ -1·6 kg/m2; P = 0·001), waist circumference (Δ -3·1 cm; P = 0·001), body fat (Δ -1·8 %; P = 0·034), as well as TAG (Δ -14·7 mg/dl; P = 0·016) and VLDL (Δ -2·8 mg/dl; P = 0·020). The HGL diet group showed a reduction in total cholesterol (Δ -14·6 mg/dl; P = 0·001), LDL (Δ -9·3 mg/dl; P = 0·029) but a reduction in HDL (Δ -3·7 mg/dl; P = 0·002). In conclusion, a 45-day intervention with low-energy HGL or LGL diets in adults with excess weight was not effective to improve arterial stiffness. However, the LGL diet intervention was associated with a reduction of reflection coefficient and improvements in body composition, TAG and VLDL levels.

Isometric handgrip training, but not a single session, reduces blood pressure in individuals with hypertension: a systematic review and meta-analysis.

Aerobic exercise is a leading strategy for the prevention/management of systemic arterial hypertension, but other modalities of exercise have also been explored. Thus, we examined the acute effect of isometric handgrip exercise (IHGE) and the chronic effect of isometric handgrip training (IHGT) on systolic blood pressure (SBP) and diastolic blood pressure (DBP) in individuals with hypertension without comorbid conditions. We conducted a systematic review with meta-analysis of randomized controlled trials (RCTs) involving adults with hypertension. We searched the electronic databases MEDLINE (PubMed), Cochrane, Web of Science, LILACS, EMBASE and PEDro. We used random-effects model for the analyses, RoB2 tool to assess the risk of bias, and GRADE to assess the strength of evidence. A total of 9 RCTs (2 for IHGE and 7 for IHGT) were selected. Compared to a control condition, IHGE did not have any effect on SBP/DBP. Unlike, the pooled mean effect of IHGT showed SBP was reduced by 6.7 mmHg (95% CI -10.3 to -3.4 mmHg) and DBP by 4.5 mmHg (95% CI -7.3 to -1.7 mmHg) in individuals with hypertension. Also, the 95% prediction interval (95% PI) of IGHT was -10.9 to -2.5 mmHg for SBP and -10.2 to +1.2 mmHg for DBP. In conclusion, while IHGE did not produce post-exercise hypotension in the population studied, IHGT reduced SBP/DBP in individuals with hypertension with clinically important reductions in SBP (-6.7 mmHg) and DBP (-4.5 mmHg). This review was registered in the International Prospective Register of Systematic Reviews (PROSPERO) (CRD 42021217958).

Dietary intake of anthocyanins improves arterial stiffness, but not endothelial function, in volunteers with excess weight: A randomized clinical trial.

Excess body weight has been associated with endothelial dysfunction and increased arterial stiffness. Foods rich in polyphenols and anthocyanins such as açaí-juçara (Euterpe edulis Martius) fruit may have protective vascular effects. Thus, we examined the effect of dietary intake of anthocyanins (açaí-juçara fruit) on endothelial function (flow-mediated dilation [FMD]) and arterial stiffness (pulse wave velocity [PWV]) in individuals with excess body weight. Fifty-five individuals with BMI ≥25 kg/m2 were randomized into non-anthocyanin (N-ATH, n = 25) or anthocyanin (ATH, n = 30) intake groups. A 12-week individualized diet plan (20% reduction in total energy intake) was prescribed and included daily intake of açaí-juçara 200 g (anthocyanins 293.6 mg) in the ATH diet plan. We evaluated anthropometric and biochemical parameters, FMD, PWV, and peripheral vascular resistance (PVR). A GEE (Bonferroni post-hoc) was used (p ≤ 0.05). No change in FMD was observed. However, PWV showed a reduction from baseline in the ATH (p = 0.002) and vs. N-ATH (p = 0.036). Both groups showed reduced peripheral vascular resistance (N-ATH, p = 0.005; ATH, p = 0.040) with no significant differences between them. In conclusion, dietary intake of anthocyanins proved effective in protecting against arterial stiffness (by PWV) in individuals with excess weight. PVR was reduced in both diet groups regardless of dietary intake of anthocyanins.

Ventilatory Muscle Training for Early Cardiac Rehabilitation Improved Functional Capacity and Modulated Vascular Function of Individuals Undergoing Coronary Artery Bypass Grafting: Pilot Randomized Clinical Trial.

Background: Cardiac rehabilitation with aerobic exercises is the first strategy for nonpharmacological treatment in the postoperative period of individuals undergoing coronary artery bypass grafting (CABG) to improve functional capacity and vascular health. However, other exercise modalities remain uncertain regarding the same benefits. Objectives: Evaluation of the effect of different modalities of exercise, such as early cardiac rehabilitation on subjects submitted to CABG in the six-minute walk test (6-MWT) and on the percentage of flow-mediated dilatation (FMD) of the brachial artery. Methods: A randomized clinical trial in which 15 patients (62.7 ± 6.7 years) who underwent CABG were randomly assigned to the following groups: isometric (IG, Handgrip Jamar®), ventilatory muscle training (VG, PowerBreathe®) and control (CG, conventional respiratory and motor physiotherapy). All patients were attended to physically twice a day (20 min/session) for a consecutive week after the CABG (hospital admission). Functional capacity was assessed by 6-MWT and endothelial function was assessed through the technique of FMD, before and after (~7 days) admission to CABG. The doppler ultrasound videos were analyzed by Cardiovascular Suite® software (Quipu, Pisa, Italy) to measure %FMD. Statistics: Generalized estimation equation, followed by Bonferroni post hoc (p < 0.05). Results: Systolic, diastolic and mean arterial pressure (SBP/DBP/MAP, respectively) were 133, 76 and 95 mmHg. The groups presented walking meters (m) distance before and after intervention of: IGbasal 357.80 ± 47.15 m vs. IGpost 306.20 ± 61.63 m, p = 0.401 (+51 m); VGbasal 261.50 ± 19.91 m vs. VGpost 300.75 ± 26.29 m, p = 0.052 (+39 m); CG basal 487.83 ± 83.23 m vs. CGpost 318.00 ± 31.08, p = 0.006 (−169 m). %FMD before and after intervention was IGbasal 10.4 ± 4.8% vs. IGpost 2.8 ± 2.5%, p = 0.152; VGbasal 9.8 ± 5.1% vs. VGpost 11.0 ± 6.1%, p = 0.825; CGbasal 9.2 ± 15.8% vs. CGpost 2.7 ± 2.6%, p = 0.710 and resting mean basal blood flow was IGbasal 162.0 ± 55.0 mL/min vs. IGpost 129.9 ± 63.7 mL/min, p = 0.662; VGbasal 83.74 ± 12.4 mL/min vs. VGpost 58.7 ± 17.1 mL/min, p = 0.041; CGbasal 375.6 ± 183.7 mL/min vs. CGpost 192.8 ± 115.0 mL/min, p = 0.459. Conclusions: Ventilatory muscle training for early cardiac rehabilitation improved acute functional capacity and modulated mean flow of individuals undergoing CABG.

Low glycaemic index and glycaemic load diets in adults with excess weight: Systematic review and meta-analysis of randomised clinical trials.

BACKGROUND: To compare the effects of low and high glycaemic index/glycaemic load (GI/GL) diets on body weight in adults with excess weight. METHODS: We searched for randomised controlled trials comparing low GI/GL vs. high GI/GL diets from Medline (via PubMed), Embase, Scopus and Web of Science. The variables of interest were anthropometric measurements, fasting glucose and fasting insulin levels and lipid profile, and 10 studies were included in the meta-analysis. RESULTS: The sample size ranged from 19 to 203 participants. Low GI/GL is not superior to high GI/GL diets on body weight reduction in adults with excess weight (body mass index [BMI] ≥ 25 kg m-2 ). However, low GI/GL diets show greater body weight reductions in adults with BMI ≥ 30 kg m-2 (-0.93 kg; 95% confidence interval [CI] = -1.73 to -0.12; p = 0.045). Compared with high GI/GL diets, low GI/GL diets may also help reduce fasting glucose (-1.97 mg dl-1 ; 95% CI = -3.76 to 0.19; p = 0.030) and fasting insulin (-0.55 µU ml-1 ; 95% CI = -0.95 to -0.15; p = 0.007). No differences in fat mass, fat-free mass, waist circumference and lipid profile were observed between low GI/GL and high GI/GL diets. The risk of bias for body weight was classified as 'low risk' (25% of the studies) and 'some concerns' for all domains of RoB 2 tool in most studies. CONCLUSIONS: When compared with high GI/GL diets, low GI/GL diets appear to more effectively reduce fasting glucose and insulin and promote greater body weight reduction in adults with obesity (BMI ≥ 30 kg m-2 ).

Effect of isometric exercise on blood pressure in prehypertensive and hypertensive individuals: protocol for a systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: Systemic arterial hypertension (HTN) is the leading risk factor of cardiovascular disease death. Lifestyle changes are key for the prevention and management of HTN. Regular aerobic exercise training is recommended as part of the management of HTN, and dynamic resistance exercise should be prescribed as an adjuvant to aerobic training. Recent evidence points to the potential benefits of isometric resistance training in reducing blood pressure (BP). Yet, the hypotensive effect of isometric exercise in prehypertensive and hypertensive individuals is not fully understood. Thus, we will examine the effect of isometric exercise in prehypertensive and hypertensive individuals through a systematic review and meta-analysis. METHODS: Our systematic review study will include randomized controlled trials (RCTs) selected from the electronic databases MEDLINE (PubMed), Cochrane, LILACS, EMBASE, Web of Science, and PEDro published in English, Spanish, and Portuguese languages. We will follow the PRISMA-P (Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols) and PICOS framework. Our search will involve studies with both male and female participants aged 18 years or more diagnosed with prehypertension or HTN performing one session of isometric exercise (acute effect) or isometric exercise training (chronic effect) compared to a control group (no exercise). We will use the Cochrane Risk of Bias 2 (RoB 2) tool to evaluate the quality of the studies and RStudio software (v1.3.959 for Windows) for statistical analyses. DISCUSSION: A meta-analysis of a homogeneous sample of prehypertensive and hypertensive individuals involving isometric handgrip exercise alone can further support previous findings and improve our understanding and recommendations for the management of these populations. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42020213081.

Efeitos de Diferentes Tipos de Treinamento Físico na Função Endotelial em Pré-Hipertensos e Hipertensos: Uma Revisão Sistemática / Effects of Different Types of Exercise Training on Endothelial Function in Prehypertensive and Hypertensive Individuals: A Systematic Review

Resumo Fundamento: A hipertensão sustentada pode levar ao remodelamento vascular e lesão das células endoteliais, o que pode explicar a disfunção endotelial encontrada em hipertensos. O treinamento físico pode melhorar a saúde vascular em indivíduos com risco cardiovascular, mas pouco se sabe sobre seus efeitos em pré-hipertensos e hipertensos. Objetivo: Revisar a literatura mostrando evidências de alterações da função endotelial em resposta a diferentes modalidades de treinamento físico em pré-hipertensos e hipertensos. Métodos: Realizamos uma revisão sistemática de estudos nas bases de dados MEDLINE, Cochrane, LILACS, EMBASE e SciELO seguindo tanto as diretrizes PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyzes) quanto a estratégia PICO (paciente/população, intervenção, comparação e resultados). Os ensaios clínicos randomizados (ECRs) publicados até abril de 2019 foram selecionados e avaliados por quatro revisores independentes. A qualidade metodológica foi avaliada por meio da escala PEDro (Physiotherapy Evidence Database). Resultados: Nossa busca rendeu 598 resumos, e 10 estudos foram elegíveis para revisão. Todos eles apresentaram qualidade metodológica aceitável pela escala PEDro. Dos 10 estudos, 7 envolveram treinamento aeróbico, 1 treinamento resistido isométrico e 2 treinamento aeróbico e treinamento resistido dinâmico separadamente. Sete estudos usaram dilatação fluxo-mediada (DFM) para avaliar a saúde vascular, e três usaram pletismografia. A maioria dos protocolos de treinamento envolveu indivíduos hipertensos e consistiu em exercícios de baixa e moderada intensidade. Conclusão: Nossa revisão sistemática mostrou que o treinamento aeróbico contínuo moderado é eficaz para melhorar a saúde vascular em indivíduos hipertensos. Em pré-hipertensos, o treinamento aeróbico intervalado vigoroso parece ser uma alternativa para benefícios à saúde vascular. O treinamento físico resistido isométrico ou dinâmico pode ser usado como alternativa secundária, mas ainda requer mais investigação.

Abstract Background: Sustained high blood pressure can lead to vascular remodeling and endothelial cell injury, which may explain the endothelial dysfunction found in hypertensive individuals. Exercise training can improve vascular health in individuals with cardiovascular risk, but little is known about its effects in prehypertensive and hypertensive individuals. Objective: To review the literature showing evidence of changes in endothelial function in response to different modalities of exercise training in prehypertensive and hypertensive individuals. Methods: We conducted a systematic review of studies in the MEDLINE, Cochrane, LILACS, EMBASE, and SciELO databases following both the PRISMA guidelines (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) and the PICO framework (patient/population, intervention, comparison and outcomes). Randomized clinical trials (RCTs) published up to April 2019 were selected and assessed by four independent reviewers. The methodological quality was assessed using the PEDro (Physiotherapy Evidence Database) scale. Results: Our search yielded 598 abstracts, and 10 studies were eligible for review. All of them had acceptable methodological quality by PEDro scale. Of the 10 studies, 7 involved aerobic training, 1 isometric resistance training, and 2 aerobic training and dynamic resistance training separately. Seven studies used flow-mediated dilation (FMD) to assess the vascular health, and three used plethysmography. Most training protocols involved hypertensive individuals and consisted of low and moderate-intensity exercise. Conclusion: Our systematic review showed that moderate continuous aerobic training is effective to improve vascular health in hypertensive individuals. In prehypertensive individuals, vigorous interval aerobic training seems to be an alternative to determine vascular health benefits. Resistance exercise training, either isometric or dynamic, can be used as a secondary alternative, but still requires further investigation.

Continuous Aerobic Training and High Intensity Interval Training Increase Exercise Tolerance in Heart Failure Patients: A Retrospective Study

Abstract Background: Conventional aerobic training is the first choice in cardiac rehabilitation for patients with chronic heart failure (CHF). However, high-intensity interval training (HIIT) may be an alternative, although it has little evidence. Objectives: To evaluate the effect of continuous aerobic training (CAT) or HIIT on exercise tolerance in CHF patients. Methods: Retrospective study with 30 patients, of both genders, members of a 10-week CAT or HIIT program. The control group (CON) consisted of patients who did not participate voluntarily in the program. Peak oxygen uptake (VO2peak), thresholds (LV1 and LV2), and ventilatory efficiency in the production of dioxide (VE/VCO2 slope), oxygen uptake efficiency (OUES), and VO2 recovery kinetics were analyzed. A two-way or repeated measures ANOVA was used, followed by Fisher's post-hoc test (p<0.05). Results: After 10 weeks of training, the CAT group increased the treadmill speed at LV1 (p=0.040), while the HIIT increased both the speed (p=0.030) and incline of the treadmill (p<0.001) for VO2peak and LV2, as well as the total time of the cardiopulmonary test. The VE/VCO2 slope was lower than that predicted for CAT (p=0.003) and HIIT (p=0.008). There was no change in VO2peak, recovery of heart rate (HR), and VO2, VE/VCO2, and OUES in both groups. Conclusions: After 10 weeks, both CAT and HIIT increased the tolerance to physical exercise. However, HIIT showed improvement in more parameters, differently from CAT.

Effects of autonomic nervous system activation on endothelial function in response to acute exercise in hypertensive individuals: study protocol for a randomized double-blind study.

BACKGROUND: Arterial hypertension has a direct association with endothelial dysfunction and major cardiovascular events. There is evidence showing the benefits of aerobic exercise on flow-mediated dilation (FMD) in hypertensive individuals but little is known about the effect of autonomic nervous system (ANS) activation on FMD of the brachial artery in response to different types of exercise in this specific population. This study aims to examine the effects of ANS activation on FMD of the brachial artery in response to exercise in hypertensive individuals following a session of different types of exercise including aerobic exercise (AE), resistance exercise (RE), or combined exercise (CE). METHODS: Thirty-nine hypertensive volunteers aged 35 to 55 years will be randomly assigned to two exercise sessions: AE (40 min on a cycle ergometer at 60% of HR reserve), RE (4 lower limb sets with 12 repetitions at 60% 1-RM for 40 min), or CE (RE for 20 min + AE for 20 min). Each exercise group will be randomized to receive either an α1-adrenergic blocker (doxazosin 0.05 mg/kg-1) or placebo. Ultrasound measurement of FMD is performed 10 min before and 10, 40, and 70 min after exercise. ANS activation is monitored using a Finometer and measurements are taken during 10 min before each FMD assessment. Arterial stiffness is assessed by pulse wave velocity (PWV) analysis using a Complior device. DISCUSSION: We expect to demonstrate the effect of ANS activation on FMD of the brachial artery in hypertensive individuals in response to different types of exercise. This study may give some insight on how to improve exercise prescription for hypertension management. TRIAL REGISTRATION: https://clinicaltrials.gov and ID "NCT04371757". Registered on May 1, 2020.

Effects of Different Types of Exercise Training on Endothelial Function in Prehypertensive and Hypertensive Individuals: A Systematic Review. / Efeitos de Diferentes Tipos de Treinamento Físico na Função Endotelial em Pré-Hipertensos e Hipertensos: Uma Revisão Sistemática.

BACKGROUND: Sustained high blood pressure can lead to vascular remodeling and endothelial cell injury, which may explain the endothelial dysfunction found in hypertensive individuals. Exercise training can improve vascular health in individuals with cardiovascular risk, but little is known about its effects in prehypertensive and hypertensive individuals. OBJECTIVE: To review the literature showing evidence of changes in endothelial function in response to different modalities of exercise training in prehypertensive and hypertensive individuals. METHODS: We conducted a systematic review of studies in the MEDLINE, Cochrane, LILACS, EMBASE, and SciELO databases following both the PRISMA guidelines (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) and the PICO framework (patient/population, intervention, comparison and outcomes). Randomized clinical trials (RCTs) published up to April 2019 were selected and assessed by four independent reviewers. The methodological quality was assessed using the PEDro (Physiotherapy Evidence Database) scale. RESULTS: Our search yielded 598 abstracts, and 10 studies were eligible for review. All of them had acceptable methodological quality by PEDro scale. Of the 10 studies, 7 involved aerobic training, 1 isometric resistance training, and 2 aerobic training and dynamic resistance training separately. Seven studies used flow-mediated dilation (FMD) to assess the vascular health, and three used plethysmography. Most training protocols involved hypertensive individuals and consisted of low and moderate-intensity exercise. CONCLUSION: Our systematic review showed that moderate continuous aerobic training is effective to improve vascular health in hypertensive individuals. In prehypertensive individuals, vigorous interval aerobic training seems to be an alternative to determine vascular health benefits. Resistance exercise training, either isometric or dynamic, can be used as a secondary alternative, but still requires further investigation.

FUNDAMENTO: A hipertensão sustentada pode levar ao remodelamento vascular e lesão das células endoteliais, o que pode explicar a disfunção endotelial encontrada em hipertensos. O treinamento físico pode melhorar a saúde vascular em indivíduos com risco cardiovascular, mas pouco se sabe sobre seus efeitos em pré-hipertensos e hipertensos. OBJETIVO: Revisar a literatura mostrando evidências de alterações da função endotelial em resposta a diferentes modalidades de treinamento físico em pré-hipertensos e hipertensos. MÉTODOS: Realizamos uma revisão sistemática de estudos nas bases de dados MEDLINE, Cochrane, LILACS, EMBASE e SciELO seguindo tanto as diretrizes PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyzes) quanto a estratégia PICO (paciente/população, intervenção, comparação e resultados). Os ensaios clínicos randomizados (ECRs) publicados até abril de 2019 foram selecionados e avaliados por quatro revisores independentes. A qualidade metodológica foi avaliada por meio da escala PEDro (Physiotherapy Evidence Database). RESULTADOS: Nossa busca rendeu 598 resumos, e 10 estudos foram elegíveis para revisão. Todos eles apresentaram qualidade metodológica aceitável pela escala PEDro. Dos 10 estudos, 7 envolveram treinamento aeróbico, 1 treinamento resistido isométrico e 2 treinamento aeróbico e treinamento resistido dinâmico separadamente. Sete estudos usaram dilatação fluxo-mediada (DFM) para avaliar a saúde vascular, e três usaram pletismografia. A maioria dos protocolos de treinamento envolveu indivíduos hipertensos e consistiu em exercícios de baixa e moderada intensidade. CONCLUSÃO: Nossa revisão sistemática mostrou que o treinamento aeróbico contínuo moderado é eficaz para melhorar a saúde vascular em indivíduos hipertensos. Em pré-hipertensos, o treinamento aeróbico intervalado vigoroso parece ser uma alternativa para benefícios à saúde vascular. O treinamento físico resistido isométrico ou dinâmico pode ser usado como alternativa secundária, mas ainda requer mais investigação.

Publisher Correction: Different exercise training modalities produce similar endothelial function improvements in individuals with prehypertension or hypertension: a randomized clinical trial.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Adaptations in GLUT4 Expression in Response to Exercise Detraining Linked to Downregulation of Insulin-Dependent Pathways in Cardiac but not in Skeletal Muscle Tissue.

Insulin resistance is associated with cardiometabolic risk factors, and exercise training can improve insulin-mediated glucose uptake. However, few studies have demonstrated the reversibility of exercise-induced benefits. Thus, the authors examine the time-response effects of exercise training and detraining on glucose transporter 4 (GLUT4) content, insulin-dependent and insulin-independent pathways in cardiac and gastrocnemius muscle tissues of spontaneously hypertensive rats. Thirty-two male spontaneously hypertensive rats, 4 months old, were assigned to (n = 8/group): T (exercise training: 10-week treadmill exercise, 50-70% maximum effort capacity, 1 hr/day, 5 days/week); D2 (exercise training + 2-day detraining), D4 (exercise training + 4-day detraining); and S (no exercise). The authors evaluated insulin resistance, maximum effort capacity, GLUT4 content, p-IRS-1Tyr1179, p-AS160Ser588, p-AMPKα1Thr172, and p-CaMKIIThr286 in cardiac and gastrocnemius muscle tissues (Western blot). In response to exercise training, there were improvements in insulin resistance (15.4%; p = .010), increased GLUT4 content (microsomal, 29.4%; p = .012; plasma membrane, 27.1%; p < .001), p-IRS-1 (42.2%; p < .001), p-AS160 (60.0%; p < .001) in cardiac tissue, and increased GLUT4 content (microsomal, 29.4%; p = .009; plasma membrane, 55.5%; p < .001), p-IRS-1 (28.1%; p = .018), p-AS160 (76.0%; p < .001), p-AMPK-α1 (37.5%; p = .026), and p-CaMKII (30.0%; p = .040) in the gastrocnemius tissue. In D4 group, the exercise-induced increase in GLUT4 was reversed (plasma membrane, -21.3%; p = .027), p-IRS1 (-37.1%; p = .008), and p-AS160 (-82.6%; p < .001) in the cardiac tissue; p-AS160 expression (-35.7%; p = .034) was reduced in the gastrocnemius. In conclusion, the cardiac tissue is more susceptible to exercise adaptations in the GLUT4 content and signaling pathways than the gastrocnemius muscle. This finding may be explained by particular characteristics of insulin-dependent and insulin-independent pathways in the muscle tissues studied.

Different exercise training modalities produce similar endothelial function improvements in individuals with prehypertension or hypertension: a randomized clinical trial Exercise, endothelium and blood pressure.

Endothelial dysfunction is a characteristic of systemic arterial hypertension (SAH) and an early marker of atherosclerosis. Aerobic exercise training (AT) improves endothelial function. However, the effects of resistance training (RT) and combined training (CT) on endothelial function remain controversial in individuals with SAH. We determined the effects of AT, RT, and CT on endothelial function and systolic (SBP)/diastolic blood pressure (DBP) in individuals with prehypertension or hypertension. Forty-two participants (54 ± 11 y, resting SBP/DBP 137 ± 9/86 ± 6 mmHg) were randomly allocated into AT (n = 14, 40 min of cycling, 50-75% heart rate reserve), RT (n = 14, 6 resistance exercises, 4 × 12 repetitions, 60% maximum strength) and CT (n = 14, 2 × 12 repetitions of RT + 20 min of AT). All participants performed a 40-minute exercise session twice a week for 8 weeks. Endothelial function was evaluated by brachial artery flow-mediated dilation (FMD). Blood pressure was evaluated through ambulatory monitoring for 24 hours. After 8 weeks of exercise training, blood pressure was reduced in all 3 groups: -5.1 mmHg in SBP (95%CI -10.1, 0.0; p = 0.003) in AT; -4.0 mmHg in SBP (95%CI -7.8, -0.5; p = 0.027) in RT; and -3.2 mmHg in DBP (95%CI -7.9, 1.5; p = 0.001) in CT. All 3 exercise training modalities produced similar improvements in FMD: + 3.2% (95%CI 1.7, 4.6) (p < 0.001) in AT; + 4.0% (95%CI 2.1, 5.7) (p < 0.001) in RT; and +6.8% (95%CI 2.6, 11.1) (p = 0.006) in CT. In conclusion, different exercise training modalities were similarly effective in improving endothelial function but impacts on ambulatory blood pressure appear to be variable in individuals with prehypertension or hypertension.

Physical training prior to myocardial infarction potentializes stem cell therapy, SDF-1/CXCR4 axis activation and inhibits the vasoconstrictor response in hypertensive rats.

Stem cell therapy is a promising strategy for recovering of injured cardiac tissue after acute myocardial infarction. The effects promoted by preventive physical training, beneficial for regeneration, are not yet understood on stem cell homing. In the present study, we evaluated the effect of preventive physical training on cell homing activation and associated mechanisms after acute myocardial infarction and therapy with adipose-derived stem cells in spontaneously hypertensive rats (SHR). Forty female SHR were allocated in sedentary (S), sedentary SHAM (S-SHAM), sedentary AMI (S-AMI), sedentary with cell therapy (S-ICT), aerobically trained (T), trained SHAM (T-SHAM), trained AMI (T-AMI) and trained with cell therapy (S-ICT) groups. Cell therapy was performed through the infusion of 2 × 105 ADSC/0.05 mL at the moment of AMI. Molecular markers of cell homing (SDF-1/CXCR4), inflammatory response (myeloperoxidase and cardiac expression of iNOS, gp91phox and NFkB), vasoconstrictor agents (Ang II and ET-1) and an angiogenesis inducer (VEGF) were measured. Functional capacity and echocardiographic parameters were also evaluated. Preventive physical training associated with cell therapy was able to reduce left ventricle ejection fraction losses in infarcted animals. Results demonstrated activation of the SDF-1/CXCR4 axis by physical training, besides a reduction in vasoconstrictor and systemic inflammatory responses. Physical training prior to AMI was able to induce a cardioprotective effect and optimize the reparative mechanism of cell therapy in an animal model of hypertension.

Impact of flaxseed and soy nuts as dietary supplements on lipid profile, insulin sensitivity, and GLUT4 expression in ovariectomized rats.

We assessed the effects of a diet with flaxseed or soy nuts versus estradiol on the lipid profile, insulin sensitivity, and glucose transporter type 4 (GLUT4) expression in ovariectomized female rats. Forty-four female Wistar rats (90 days old) underwent ovariectomy and were divided into 4 groups: C (standard diet), E (standard diet + subcutaneous 17ß-estradiol pellets), L (standard diet + flaxseed + subcutaneous placebo pellets), and S (standard diet + soy nuts + subcutaneous placebo pellets). Customized diets and the insertion of pellets were started 21 days after ovariectomy and were continued for another 21 days. We measured body mass, insulin tolerance, total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglycerides, and GLUT4 (in cardiac and adipose tissues). We found a lower body mass and a lower Lee index in group E and a trend toward improved insulin sensitivity in group S (p = 0.066). Groups L and S showed a better lipid profile when compared with group C. Microsomal GLUT4 increased in group L (in cardiac and adipose tissues), and plasma membrane GLUT4 increased in groups E, L, and S (in both tissues). We conclude that flaxseed and soy nuts as dietary supplements improve lipid profile and increase GLUT4 expression.

ß-blockers interfere with cell homing receptors and regulatory proteins in a model of spontaneously hypertensive rats.

AIM: To examine the interference of ß-blockers with the chemokine stromal cell-derived factor-1 (SDF-1) found in cell homing receptors, C-X-C chemokine receptor type 4 (CXCR-4) and CXCR-7, and regulatory proteins of homing pathways, we administered atenolol, carvedilol, metoprolol, and propranolol for 30 days using an orogastric tube to hypertensive rats. METHOD: We collected blood samples before and after treatment and quantified the levels of SDF-1 with enzyme-linked immunosorbent assay (ELISA). On day 30 of treatment, the spontaneously hypertensive rats (SHR) were euthanized, and heart, liver, lung, and kidney tissues were biopsied. Proteins were isolated for determining the expression of CXCR-4, CXCR-7, GRK-2 (G protein-coupled receptors kinase 2), ß-arrestins (ß1-AR and ß2-AR), and nuclear factor kappa B (NFκB). RESULTS: We found that the study drugs modulated these proteins, and metoprolol and propranolol strongly affected the expression of ß1-AR (P = .0102) and ß2-AR (P = .0034). CONCLUSION: ß-blockers modulated tissue expression of the proteins and their interactions following 30 days of treatment. It evidences that this class of drugs can interfere with proteins of cell homing pathways.

Cardiac parameters and endothelial function in a strength athlete: a case report

We aimed to discuss a case of strength training athlete who competes in international competitions regarding cardiac (dimension and function), vascular (endothelium and vascular resistance), hemodynamic (blood pressure), given limited evidence supporting these cardiovascular adaptations as well as concerning endothelial function in long-term high-intensity strength training. Methods: We assessed heart structure and function (echocardiography); systolic (SBP) and diastolic blood pressure (DBP); endothelium-dependent vasodilation (flow-mediated dilation, FMD); maximum force tested in the squat, bench press, and deadlift; and maximum oxygen consumption (spirometry). Results: powerlifter's cardiac dimensions (interventricular septum 13 mm; posterior wall thickness 12 mm; LV diastolic diameter 57 mm; left ventricle mass 383 g; LV mass adjusted by body surface area 151.4 g/m2) are above the proposed cutoff values beyond which pathology may be considered. Moreover, cardiovascular function systolic (ejection fraction by Simpson's rule, 71%) is preserved and FMD measure is fairly close and above normal; however, a mild increase in systolic and diastolic blood pressure was observed (130/89 mmHg, respectively). Conclusion: Cardiac remodeling cannot be viewed as either pathological or harmful to the cardiovascular system. Furthermore, we showed an improvement in endothelial function.(AU)

Cardiovascular changes in animal models of metabolic syndrome.

Metabolic syndrome has been defined as a group of risk factors that directly contribute to the development of cardiovascular disease and/or type 2 diabetes. Insulin resistance seems to have a fundamental role in the genesis of this syndrome. Over the past years to the present day, basic and translational research has used small animal models to explore the pathophysiology of metabolic syndrome and to develop novel therapies that might slow the progression of this prevalent condition. In this paper we discuss the animal models used for the study of metabolic syndrome, with particular focus on cardiovascular changes, since they are the main cause of death associated with the condition in humans.

GLUT4 content decreases along with insulin resistance and high levels of inflammatory markers in rats with metabolic syndrome.

BACKGROUND: Metabolic syndrome is characterized by insulin resistance, which is closely related to GLUT4 content in insulin-sensitive tissues. Thus, we evaluated the GLUT4 expression, insulin resistance and inflammation, characteristics of the metabolic syndrome, in an experimental model. METHODS: Spontaneously hypertensive neonate rats (18/group) were treated with monosodium glutamate (MetS) during 9 days, and compared with Wistar-Kyoto (C) and saline-treated SHR (H). Blood pressure (BP) and lipid levels, C-reactive protein (CRP), interleukin 6 (IL-6), TNF-α and adiponectin were evaluated. GLUT4 protein was analysed in the heart, white adipose tissue and gastrocnemius. Studies were performed at 3 (3-mo), 6 (6-mo) and 9 (9-mo) months of age. RESULTS: MetS rats were more insulin resistant (p<0.001, all ages) and had higher BP (3-mo: p<0.001, 6-mo: p = 0.001, 9-mo: p = 0.015) as compared to C. At 6 months, CRP, IL-6 and TNF-α were higher (p<0.001, all comparisons) in MetS rats vs H, but adiponectin was lower in MetS at 9 months (MetS: 32 ± 2, H: 42 ± 2, C: 45 ± 2 pg/mL; p<0.001). GLUT4 protein was reduced in MetS as compared to C rats at 3, 6 and 9-mo, respectively (Heart: 54%, 50% and 57%; Gastrocnemius: 37%, 56% and 50%; Adipose tissue: 69%, 61% and 69%). CONCLUSIONS: MSG-treated SHR presented all metabolic syndrome characteristics, as well as reduced GLUT4 content, which must play a key role in the impaired glycemic homeostasis of the metabolic syndrome.

The beneficial effects of exercise in rodents are preserved after detraining: a phenomenon unrelated to GLUT4 expression.

BACKGROUND: Although exercise training has well-known cardiorespiratory and metabolic benefits, low compliance with exercise training programs is a fact, and the harmful effects of physical detraining regarding these adaptations usually go unnoticed. We investigated the effects of exercise detraining on blood pressure, insulin sensitivity, and GLUT4 expression in spontaneously hypertensive rats (SHR) and normotensive Wistar Kyoto rats (WKY). METHODS: Studied animals were randomized into sedentary, trained (treadmill running/5 days a week, 60 min/day for 10 weeks), 1 week of detraining, and 2 weeks of detraining. Blood pressure (tail-cuff system), insulin sensitivity (kITT), and GLUT4 (Western blot) in heart, gastrocnemius and white fat tissue were measured. RESULTS: Exercise training reduced blood pressure (19%), improved insulin sensitivity (24%), and increased GLUT4 in the heart (+34%); gastrocnemius (+36%) and fat (+22%) in SHR. In WKY no change in either blood pressure or insulin sensitivity were observed, but there was an increase in GLUT4 in the heart (+25%), gastrocnemius (+45%) and fat (+36%) induced by training. Both periods of detraining did not induce any change in neither blood pressure nor insulin sensitivity in SHR and WKY. One-week detraining reduced GLUT4 in SHR (heart: -28%; fat: -23%) and WKY (heart: -19%; fat: -22%); GLUT4 in the gastrocnemius was reduced after a 2-week detraining (SHR: -35%; WKY: -25%). There was a positive correlation between GLUT4 (gastrocnemius) and the maximal velocity in the exercise test (r = 0.60, p = 0.004). CONCLUSIONS: The study findings show that in detraining, despite reversion of the enhanced GLUT4 expression, cardiorespiratory and metabolic beneficial effects of exercise are preserved.