Few studies have compared cortisol responses to psychological and physical stress tasks with or without social evaluation. Flow-mediated dilation (FMD) with reactive hyperemia is impaired following acute stress though less is known regarding the impact of stress and cortisol on FMD with exercise induced increases in shear stress (EX-FMD). The purpose of this study was 1) to compare cortisol responses between the Trier Social Stress Test (TSST) and 5min cold pressor test with and without social evaluation (CPT, CPT+SE) and 2) to examine the impact of these stressors and cortisol elevation on EX-FMD. 59 healthy male subjects were randomly assigned to one of three conditions: TSST, CPT, or CPT+SE. Brachial artery EX-FMD was assessed before, 15 and 35min post-stress with Echo and Doppler ultrasound. Results are mean ± SD. Baseline parameters did not differ between conditions (p>.05) and stress responses were similar between the three conditions for peak cortisol: TSST 11.34±5.53nmol/L; CPT 10.08±4.48nmol/L; CPT+SE 8.51±3.60nmol/L; condition effect p=.292; cortisol responders only (increase >2nmol/L) TSST 12.48±5.24nmol/L; CPT 12.13±5.31nmol/L; CPT+SE 10.70±2.86nmol/L; condition effect p=.560; peak MAP: 131.99 ±18.56mmHg, condition effect p=.664; peak TPR: 25.84 ± 9.78mmHg/L/min, condition effect p=0.841; peak stress rating out of 10: 5.11 ± 2.12, condition effect p= 0.292; with the exception of HR (TSST: 95.06 ± 15.29bpm; CPT: 79.00 ± 11.85bpm; CPT+SE: 77.98 ± 7.66bpm; condition effect p= 0.003) and pain ratings out of 10 (TSST: 1.21 ± 1.72; CPT: 6.66 ± 1.42; CPT+SE: 6.38 ± 1.73; condition effect p<.001). Shear stress was lower in the 15min post-stress vs. pre stress and 35min post-stress trials (72.34 ± 4.46; 15min post-stress: 70.79 ± 5.39; 35min post-stress: 70.60 ± 6.10; condition effect p= 0.592; trial effect: p= 0.018). EX-FMD increased from pre- stress to 15min post-stress in all conditions (pre-stress 6.22 ± 2.75%; 15min-post stress: 7.91 ± 3.24%; 35min post-stress: 6.60 ± 2.93%; trial effect p<.001). No correlation between change in EX-FMD and change in cortisol was detected (r2= 0.0125; p=.404). In conclusion, the TSST, CPT and CPT+SE elicited similar stress responses and stress transiently enhanced EX-FMD. Cortisol responses did not explain the enhanced EX-FMD post stress. / Thesis (Master, Kinesiology & Health Studies) -- Queen's University, 2012-09-14 15:41:33.325

Heat therapy may be an alternative or adjunct intervention to exercise training for improving cardiovascular function and health. However, its prescription must be refined in order to overcome the feasibility and tolerability issues associated with current whole-body heating modes. There is substantial evidence to support the beneficial effects of high doses (e.g., frequency, duration, and intensity) of heating typically achieved using whole-body modes, but there is limited knowledge on whether lower doses of heating administered through local hot water immersion of the limbs can still have an impact on vascular function. All studies were conducted in heathy young men and women. In the first study, we found that regardless of whether local heating was applied to the lower limbs up to the ankles or knees, upper limb endothelial function and lower limb arterial stiffness improved acutely. In the second study, we proceeded to prescribe ankle-level heating in a chronic intervention and compared its effects to that of moderate-intensity cycling exercise training. We observed no changes in endothelial function, but decreases in central arterial stiffness and increases in cardiorespiratory fitness in those who performed heat therapy and exercise training combined with heat therapy. In the third study, we evaluated the ability of acute vascular function responses to predict chronic vascular function responses with heating and exercise interventions, and found significant positive associations between the acute and chronic responses for absolute and relative brachial artery flow-mediated dilation and femoral-foot pulse wave velocity. These findings suggest that, in healthy young men and women, local heating through ankle-level hot water immersion can improve indices of cardiovascular function both acutely and chronically, alone or combined with exercise training. Further, acute responses may be used to determine an individual’s chronic responsiveness to a heat therapy and/or exercise training intervention. More research in larger, more diverse samples and with a longer duration of therapy and/or training should be conducted to determine if the results are replicable. / Dissertation / Doctor of Philosophy (PhD) / Regular participation in whole-body heat therapy can extend health and life span, but it is used infrequently because of a lack of feasibility from a cost, accessibility, and tolerability standpoint. This thesis explored whether local heat therapy in young healthy men and women would be effective for improving blood vessel health defined as endothelial function and arterial stiffness, both of which are linked to the risk of developing many chronic diseases. Furthermore, the effects of local heat therapy were compared to that of exercise training. We found that there were beneficial short- and long-term effects of lower limb hot water immersion that manifested in different areas of the body. Local heat therapy improved upper limb endothelial function and lower limb arterial stiffness immediately after a session, whereas with repeated exposure, it may have improved central arterial stiffness and cardiorespiratory fitness. Exercise training only had beneficial effects on the blood vessels when combined with heat therapy. Finally, short-term vascular responses can predict long-term vascular responses to both heat therapy and/or exercise training. Overall, our findings suggest that there may be some utility for local heat therapy to promote healthy blood vessels, but more work must be done to replicate our findings and explore its effects on other populations.

The development of atherosclerotic lesions and endothelial cell damage can originate during early childhood. Endothelial cells produce and release vasodilatory chemicals, which dictate the artery’s ability to vasodilate or vasoconstrict. Brachial artery FMD is a non-invasive, reproducible and a sensitive technique used to detect changes in arterial diameter and is correlated with coronary artery endothelial function. Cross-sectional studies have indicated increases in arterial diameter in children between the ages of 6-18 years however, a longitudinal, observational design study has not been conducted to understand how arterial diameters and FMD change over time in children, with considerations for the influences of physical activity and sex. The purpose of this study was to understand the impact of age and sex on arterial diameter and FMD and investigate the effects of habitual moderate-to-vigorous physical activity (MVPA) during both the school-age and preschool years on endothelial function trajectories during the school-age years. Over three years, 418 children between 3-5 years old participated in the HOPP study annually, and 279 of these children attended the lab when they were between 6-12 years old for an additional 3 annual visits in the SKIP study. Habitual MVPA was measured for 7 days in both the HOPP and SKIP studies each year, and FMD was measured each year during SKIP. Linear mixed-effects modeling was implemented to study the trend in FMD and the influence of chronological and biological age, sex and MVPA on arterial function; effects are reported as unstandardized estimates (Est). Boys had larger baseline and peak brachial artery diameters compared to girls (p<0.001). Girls had larger brachial artery FMD compared to boys (6.82±3.39 vs. 6.23±3.50 %, p<0.001). There was an effect of MVPA in the SKIP study on allometrically scaled FMD (Est. -0.017, p=0.03), but not on relative FMD (Est. -0.01, p=0.17). MVPA in the preschool years did not predict school-aged scaled FMD (Est. 0.11, p=0.24) or FMD (Est. -0.003, p=0.64). The observed trends in brachial artery diameter and FMD are in-line with expected changes in growth and maturation in children. Children who engaged in more habitual MVPA during the childhood years, but not the preschool years, demonstrated changes endothelial function during the school-age years. / Thesis / Master of Science (MSc) / It is clear that preliminary signs of atherosclerosis begin during the early years of childhood, and typically precede the development of future cardiovascular disease. Engaging in habitual physical activity at higher intensities, has been shown to positively influence cardiovascular health, specifically in central and peripheral arteries. This study sought to investigate the trends in vascular heath over time in children and examine the effect of moderate-to-vigorous physical activity engagement during the preschool years on vascular health during the school-age years. Our results suggest that as children age, their arteries get bigger in size and that school-aged girls have elevated vascular function when compared to boys. Children who engage in greater amounts of moderate-to-vigorous physical activity during their school-age years does not influence measures of vascular health. Additionally, engagement in habitual moderate to vigorous physical activity during the preschool years does not impact these vascular health relationships during the school-age years.

A criterion method to evaluate cardiorespiratory health is measuring peak oxygen consumption (VO2 peak) from a maximal graded exercise test (GXT). While VO2 peak is a valuable measure, heart rate recovery (HRRec) and endothelial function (EF) also describe cardiorespiratory health and fitness. The purpose of this study was to investigate whether differences exist in VO2 peak, HRRec, and EF between healthy-weight (HW) and obese (OB) women and children and to determine if there were significant correlations among these variables. A total of 60 women and children participated in this study. Anthropometric, body composition, resting heart rate and blood pressure (BP) were measured. EF was evaluated to determine the reactive hyperemia index (RHI). Finally, each subject performed a graded exercise test (GXT) to determine VO2 peak. Following the GXT, the subjects’ recovery responses were monitored for 5 minutes. A factorial MANOVA was used to evaluate differences between obesity status and age in relative VO2 peak and relative HRRec. The MANOVA resulted in a significant (p < 0.001) main effect for obesity status and age, but there was no interaction effect. HW individuals had a greater relative VO2 peak compared to OB individuals. Children had a greater relative VO2 peak and HRRec compared to adults. Absolute VO2 peak and absolute HRRec were examined using univariate ANOVAs. Women had greater absolute VO2 peak values compared to children (p2 peak and absolute HRRec, relative HRRec, and RHI. Relative VO2 peak was significantly correlated to RHI. Absolute HRRec was correlated with relative HRRec and RHI. Relative HRRec was correlated with RHI. Lack of significant differences in HRRec and EF across adiposity levels were likely due to the obese, but otherwise healthy population recruited for this study. Age affected the response to all variables included in this study.

The goal of this dissertation research was to describe the relationships among psychosocial variables, physical activity and physical fitness, and biological measures indicative of cardiovascular health in Mexican American male adolescents using a biobehavioral model. One aim of the research was to describe the predictive relationship of psychosocial variables, perceived benefits, perceived barriers, self-efficacy, and interpersonal influences, on physical activity and physical fitness. A second aim described the predictive relationship among physical activity and physical fitness and the amount of body fat and levels of biological markers indicative of endothelial function in this population. Study participants were 28 Mexican American male adolescents ages 15-19. Psychosocial variables were assessed using instruments developed for adolescents by Pender. Physical activity was measured by a 3-day accelerometer recording of activity counts while physical fitness was measured with cycle ergometry withVO2 max. Biologic measures indicative of cardiovascular health included serum leptin, CRP, adiponectin. Fat mass was assessed using BMI and DEXA scans. Findings demonstrated partial support for the model. Psychosocial variables predictive of physical fitness included perceived benefits of action and interpersonal influences. Perceived benefits of exercise significantly predicted physical fitness, explaining 50% of the variance in physical fitness scores while exercise norms, a measure of interpersonal influence, predicted 17% of the variance. Self-efficacy did not meet criteria as a mediating variable; it directly predicted physical activity. Physical activity predicted 15% of the variance in body fat measured as BMI percentile. Physical fitness predicted Leptin levels accounting for 23% of the variance. Physical fitness also predicted 51% of the variance related to the DEXA-derived body fat measurement and 18% of the variance related to BMI. Additional trends were identified including lack of parental support for exercise. Although the study participants reported high acculturated levels, language spoken at home indicated that the family was less acculturated which may have accounted for the lack of parental support. Higher acculturation levels were also significantly associated with increased perceived benefits of action and higher BMI levels. In conclusion, this study suggests that selected psychosocial variables including interpersonal influences should be considered in designing research with Mexican American adolescent males. In addition results suggest that objectively obtained measures of physical fitness and activity are in part predictive of measures of endothelial function and body fat.

Vitamin D deficiency in patients with chronic kidney disease, measured by reduced serum concentrations of 25 hydroxy vitamin D, is highly prevalent and associated with both endothelial dysfunction and an increased risk of cardiovascular disease. Observational studies in chronic kidney disease have demonstrated that vitamin D therapy reduces the risk of cardiovascular disease. In patients with chronic kidney disease and concomitant vitamin D deficiency, the effect of vitamin D therapy on endothelial function, which is associated with cardiovascular disease, is poorly understood. The mechanism by which vitamin D affects endothelial function is unclear. Methods Presented in this thesis, two studies have addressed these issues: 1. A double blind, randomized controlled trial evaluating the effect of ergocalciferol compared to placebo on microcirculatory endothelial function in patients with non-dialysis chronic kidney disease and concomitant vitamin D deficiency 2. In vitro and in vivo experiments to determine the mechanistic effect of ergocalciferol on endothelial function in an experimental model of uraemia. Results In the clinical study, ergocalciferol increased vitamin D serum concentrations and improved microcirculatory endothelial function measured by laser Doppler flowmetry after iontophoresis of acetylcholine. Oxidative stress measured by skin autofluorescence for advanced glycation end products did not change in the ergocalciferol group but increased significantly in the placebo group. Ergocalciferol increased endothelial nitric oxide synthase expression and activity in cultured human endothelial cells and improved endothelial function in an in vivo model of mild uraemia. The findings from the in vivo and clinical studies occurred independently of changes in blood pressure, conduit artery function, serum calcium, phosphate and parathyroid hormone supporting in vitro findings that ergocalciferol acts directly on the endothelium. Conclusion Ergocalciferol improved endothelial function in both rodent and human subjects with chronic kidney disease. Experimental evidence suggests this effect occurs through an endothelium dependent mechanism involving changes in the upregulation and function of endothelial nitric oxide synthase.

Ingestion of vegetables rich in inorganic nitrate (NO3-) content has emerged as an effective method, via the formation of a nitrite (NO2-) intermediate, for acutely elevating vascular nitric oxide (NO) levels. As such a number of beneficial effects of NO3- ingestion have been demonstrated including the suggestion that platelet reactivity is reduced. I initially investigated whether inorganic NO3- supplementation might also reduce platelet reactivity in healthy volunteers and have determined the mechanisms involved in the effects seen. I conducted a randomised crossover study in 24 (12 of each sex) healthy subjects assessing the acute effects of potassium nitrate capsules (KNO3, 8 mmol) vs placebo (KCl) control capsule ingestion on platelet reactivity. Inorganic NO3- ingested via supplementation raised circulating NO3- and NO2- levels in both sexes and attenuated ex vivo platelet aggregation responses to adenosine diphosphate (ADP) and, albeit to a lesser extent, collagen but not epinephrine in male but not female volunteers. These inhibitory effects were associated with a reduced platelet P-selectin expression and elevated platelet cyclic guanosine monophosphate (cGMP) levels. In addition, I have shown that NO2- reduction to NO occurs at the level of the erythrocyte and not the platelet. These results demonstrate that inorganic NO3- ingestion, whether via the diet or through supplementation, results in a modest decrease in platelet reactivity in healthy males. I then sought to examine the effects of 6 weeks daily intake of NO3--rich beetroot juice versus a placebo NO3--deplete juice on endothelial and platelet function in a cohort of otherwise healthy non-diabetic untreated hypercholesterolaemics. In this randomised double blind placebo controlled parallel study 69 subjects were recruited. The primary end point was change in endothelial function determined using ultrasound flow-mediated dilatation (FMD). Secondary endpoints included change in pulse wave analysis (PWA), aortic pulse wave velocity (aPWV), platelet P-selectin and platelet monocyte aggregate (PMA) expression and plasma, urine and salivary NO3- and NO2- levels. Baseline characteristics, including lipid levels, were similar between the groups. Dietary NO3- caused an improvement in FMD of ~24% from 4.6%±2.2% to 5.7%±2.6% in the treatment group (p<0.001) not seen in the placebo group (4.5%±1.9% versus 4.3%±1.8% p=0.07). This improvement in FMD was also noted following acute administration of dietary NO3-. Small but significant improvements also occurred in aPWV and PWA augmentation index (p=0.04). The % of platelet monocyte aggregates was significantly reduced in the NO3- limb by 7.6% versus an increase of 10.1% in the placebo group (p=0.004). No adverse effects of dietary NO3- were detected. In this study population, chronic dietary NO3- ingestion improves endothelial function, vascular stiffness and platelet markers of atherogenesis in a cohort of hypercholesterolaemics who are otherwise at increased risk of cardiovascular disease (CVD). This thesis provides strong support for assessment of the potential of dietary NO3- as a primary prevention strategy to prevent atherothrombotic and atherogenic complications in larger cohorts.

Cardiovascular disease is the leading cause of death in the developed world. The majority of cardiovascular diseases are characterized by disorders of the arteries, predominantly caused by endothelial dysfunction and arterial stiffening. Passive heat stress results in elevations in core temperature (inducing heat shock protein expression) and changes in cardiovascular hemodynamics, such as increased cardiac output and shear stress, that are similar to exercise. Thus, repeated passive heat stress (“heat therapy”) may provide an alternative means of improving cardiovascular health, particularly for patients with limited exercise tolerance and/or capabilities. Therefore, the goal of this dissertation was to perform integrative studies to determine the effects of heat therapy on vascular function and the associated cellular pathways in young, sedentary humans. Twenty subjects were assigned to participate in 8 weeks (4-5x/week) of heat therapy (N=10; immersion in a 40.5°C bath sufficient to maintain rectal temperature ≥38.5°C for 60 min/session) or thermoneutral water immersion (N=10; sham). As discussed in Chapter V, we found that heat therapy improved numerous well-established biomarkers of conduit vessel/macrovascular function, including flow-mediated dilation (a measure of endothelial function), arterial stiffness, intima media thickness, and blood pressure. Heat therapy also improved microvascular function, as discussed in Chapter VI, measured as improved cutaneous thermal hyperemia and nitric oxide-dependent dilation (the difference between microdialysis sites receiving Lactated Ringer’s [control] and nitric oxide synthase inhibition). No changes were observed in any variables in sham subjects. In Chapter VII, we showed that both direct cellular heating and serum collected from human subjects following heat therapy improved nitric oxide bioavailability and angiogenesis in cultured endothelial cells, providing potential mechanisms by which heat therapy improves vascular function in vivo. Therefore, the studies described herein provide comprehensive evidence that passive heat therapy improves vascular health and insight into the mechanisms involved. Our data presented in Chapters IV-VII, combined with pilot data we conducted in spinal cord injured individuals (Chapter VIII), strongly indicate that passive heat therapy could be used as a simple and effective tool to improve cardiovascular health in a variety of patient populations. This dissertation includes published and unpublished co-authored material.

Introdução. A prática regular do exercício de força (EF) está associada a adaptações metabólicas, neuromusculares e cardiovasculares que repercutem de maneira positiva sobre a saúde e qualidade de vida de seus praticantes. No entanto, Indivíduos sedentários apresentam comprometimentos agudos na função endotelial após EF de alta intensidade. Objetivo. Avaliar a função endotelial de indivíduos sedentários de meia idade em resposta a diferentes intensidades do EF. Métodos. 11 indivíduos sedentários (40,1±3,9 anos; 27,3±1,4 kg/m2) realizaram EF em três condições experimentais: extensão de joelhos a 50% de 1RM (MI), 80% de 1RM (AI) e repouso na condição controle (CON). Foi realizada avaliação da vasodilatação mediada pelo fluxo (FMD) antes, 30 minutos após e 60 minutos após os protocolos. A quantificação das concentrações de NO2 e NO3 (NOx), endotelina-1 (ET-1) e TBARS foram realizadas antes, imediatamente após e 60 minutos após os protocolos. A pressão arterial foi mensurada antes e após os protocolos Resultados. A FMD aumentou significativamente 30 minutos após o exercício na condição MI (12,5± 4,10 para 17,2±3,9 %; p=0,01) bem como os níveis de NOx (6,8± 3,3 vs. 12,6± 4,2μM; p= 0,007). A concentração de ET-1 aumentou imediatamente após na condição AI (20,02±2,2 vs. 25,4± 2,1pg/ml; p= 0,004). A elevação da pressão arterial não diferiu entre as condições MI e AI. As concentrações de TBARS não se alteraram ao longo dos protocolos. Conclusão. O EF de moderada intensidade aumenta a FMD e os níveis NOx após uma sessão aguda de exercício em indivíduos sedentários de meia idade, estes resultados sugerem que menores intensidades do EF são mais seguras ao iniciar um programa de exercícios. / Regular resistance exercise (RE) is associated with metabolic, neuromuscular and cardiovascular adaptation that results in improvement of quality of life and health. However, sedentary subjects have been showing an acute impairment on endothelial function after high intensity resistance exercise. The aim of this study was to evaluate the endothelial function in sedentary middle age men after RE in different intensities. Methods. Eleven middle age sedentary men (40,1±3,9 years; 27,3±1,4 kg/m2) performed RE in three different conditions: knee extension at 50% of one 1RM (MI), at 80% of 1RM (HI) and rest in the control group (CON). Flow mediated dilation (FMD) was assessed before, 30 and 60 minutes of exercise. Venus plasma concentration of ET-1 NOx and TBARS were measured before, immediately after and 60 minutes after exercise. Blood pressure was evaluated before and after exercise. Results. There was a significant improvement in FMD 30 minutes after exercise in the MI condition (12,5± 4,10 vs 17,2±3,9%; p= 0,016; p=0,01). The plasma NOx concentration was significant higher immediately after MI (6,8± 3,3 vs. 12,6± 4,2μM; p= 0,007). There was a significant improvement in the plasma ET-1 concentration immediately after HI (20,02±2,2 vs. 25,4± 2,1pg/ml; p= 0,004). There was no significant difference in the BP between the experimental conditions (MI vs HI) and TBARS throughout the experimental conditions. Conclusions. Resistance exercise performed in moderate intensity improve endothelial function in sedentary middle aged men, there results suggest that lower intensities of RE could be safe for this population in the beginning of the exercise programs.

Conselho Nacional de Desenvolvimento Científico e Tecnológico / As doenças cardiovasculares são a principal causa de morte nos países ocidentais. Alguns estudos sugerem que o chá verde tem efeito benéfico sobre diferentes fatores de risco cardiovascular. No entanto, outros estudos não mostraram essa associação. Objetiva avaliar em mulheres pré-hipertensas obesas o efeito do consumo de chá verde sobre: a pressão arterial, a função endotelial, o perfil metabólico, a atividade inflamatória e a adiposidade corporal. Estudos clínico, randomizado, cruzado, duplo-cego e placebo-controlado. Durante 4 semanas as mulheres foram orientadas a ingerir 3 cápsulas de extrato de chá verde por dia (500mg extrato chá verde/cápsula) passando por 2 semanas de washout e posteriormente ingeriam por mais 4 semanas o placebo. As mulheres que iniciaram o estudo tomando placebo posteriormente utilizaram o chá verde. Ou seja, todas as pacientes receberam chá verde e placebo por um mesmo período. No início e final de cada tratamento foram analisadas as variáveis. Foram avaliadas 20 mulheres pré-hipertensas, obesidade grau I e II, idade entre 25 e 59 anos. O local do estudo foi o Laboratório da Disciplina de Fisiopatologia Clínica e Experimental Clinex. Universidade do Estado do Rio de Janeiro. As variáveis estudadas foram a pressão arterial, índice de hipertemia reativa (avaliada com Endo-PAT2000), proteína C reativa, interleucina-6, fator de necrose tumoral-&#945;, molécula de adesão intercelular e molécula de adesão vascular celular, inibidor de ativador do plasminogênio, fator de crescimento endotelial vascular, E-selectina, adiponectina, colesterol total, LDL-colesterol, HDL-colesterol, triglicérides, glicemia, insulina, HOMA, índice de massa corporal, circunferência de cintura, circunferência de quadril, relação cintura quadril e percentual de gordura corporal. Como resultados, na avaliação da pressão arterial pela monitorização ambulatorial da pressão arterial, observou-se redução significativa da pressão arterial sistólica de 24 horas (pré 130,31,7 mmHg vs. pós 127,02,0 mmHg; p= 0,02), pressão arterial sistólica diurna (pré 134,01,7 mmHg vs. pós 130,72,0 mmHg; p= 0,04) e pressão arterial sistólica noturna (pré 122,21,8 mmHg vs. pós 118,42,2 mmHg; p= 0,02), após o consumo do chá verde, em comparação ao uso do placebo. Após o consumo do chá verde foi observado aumento, embora estatisticamente não significativo, no índice de hiperemia reativa (pré 1,980,10 vs. pós 2,220,14), além de redução expressiva na concentração da molécula de adesão intercelular (pré 91,88,0 ng/ml vs. pós 85,85,6 ng/ml) e do fator de crescimento endotelial vascular (pré 195,846,2 pg/ml vs. pós 158,638,7 pg/ml), porém sem significância estatística. As demais variáveis avaliadas não se modificaram de forma significativa após o consumo do chá verde, em comparação ao placebo. Foi observada forte correlação entre redução de pressão arterial sistólica e diastólica de 24hs, avaliada pela monitorização ambulatorial da pressão arterial, e o aumento do índice de hipertemia reativa (r= -0,47; r= -0,50, respectivamente). Os resultados do presente estudo sugerem que o chá verde tem efeito benéfico sobre a pressão arterial e possivelmente sobre a função endotelial. / Cardiovascular diseases are the leading cause of mortality in Western countries. Some studies have suggested that green tea has beneficial effects on different cardiovascular risk factors. However, others have failed to show such an association. Objective to evaluate the effects of green tea on blood pressure, endothelial function, metabolic profile, inflammatory activity and body adiposity in obese pre-hypertensive women. Study clinical, randomized, crossover, double-blinded, placebo-controlled. During 4 weeks women were instructed to ingest 3 capsules of green tea extract per day (500mg green tea extract/capsule), after 2 weeks of washout and then ingested placebo for 4 weeks. The women who began the study with placebo later have used green tea. That is, all patients received placebo and green tea for the same period. At the beginning and end of each treatment the variables were analyzed. Study of 20 women with pre-hypertension, obesity grade I and II, aged between 25 and 59 years. Study site in Laboratory of the Discipline of Clinical and Experimental Pathophysiological Clinex. Rio de Janeiro State University. Variables studied was blood pressure, reactive hyperemia index (evaluated with Endo-PAT2000), C-reactive protein, interleukin 6, tumor necrosis factor alpha, vascular cell adhesion molecule, intercellular adhesion molecule, plasminogen activator inhibitor-1, vascular endothelial growth factor, E-selectin, adiponectin, total cholesterol, low density lipoprotein-cholesterol, high density lipoprotein-cholesterol, triglycerides, blood glucose, insulin, HOMA, body mass index, waist circumference, hip circumference, waist-to-hip ratio and body fat. As results, in the assessment of blood pressure by ambulatory blood pressure monitoring was observed significant reduction in 24 hours systolic blood pressure (pre 130.31.7 mmHg vs. post 127.02.0 mmHg; p= 0.02), daytime systolic blood pressure (pre 134.01.7 mmHg vs. post 130.72.0 mmHg; p= 0.04) and nighttime systolic blood pressure (pre 122.21.8 mmHg vs. post 118.42.2 mmHg; p= 0.02), after consumption of green tea compared with placebo. After consumption of green tea, there was an increase, although not statistically significant, in reactive hyperemia index (pre 1.980.10 vs. post 2.220.14), besides expressive reduction in the concentration of intercellular adhesion molecule (pre 91.88.0 ng/ml vs. post 85.85.6 ng/ml) and vascular endothelial growth factor (pre 195.846.2 pg/ml vs. post 158.638.7 pg/ml), however without statistical significance. The other variables evaluated did not change significantly after consumption of green tea. A strong correlation was observed between reduction in 24 hours systolic blood pressure and 24 hours diastolic blood pressure, assessed by ambulatory blood pressure monitoring, and the increase of reactive hyperthermia index (r= -0.47; r= -0.50, respectively). The results of this study suggest that green tea has a beneficial effect on blood pressure and possibly on endothelial function.