Endothelial Effect of Statin Therapy at a High Dose Versus Low Dose Associated with Ezetimibe / Efeito Endotelial da Terapia com Estatina em Alta Dose versus Baixa Dose Associada à Ezetimiba

Abstract Background: The effect of statins on the endothelial function in humans remains under discussion. Particularly, it is still unclear if the improvement in endothelial function is due to a reduction in LDL-cholesterol or to an arterial pleiotropic effect. Objective: To test the hypothesis that modulation of the endothelial function promoted by statins is primarily mediated by the degree of reduction in LDL-cholesterol, independent of the dose of statin administered. Methods: Randomized clinical trial with two groups of lipid-lowering treatment (16 patients/each) and one placebo group (14 patients). The two active groups were designed to promote a similar degree of reduction in LDL-cholesterol: the first used statin at a high dose (80 mg, simvastatin 80 group) and the second used statin at a low dose (10 mg) associated with ezetimibe (10 mg, simvastatin 10/ezetimibe group) to optimize the hypolipidemic effect. The endothelial function was assessed by flow-mediated vasodilation (FMV) before and 8 weeks after treatment. Results: The decrease in LDL-cholesterol was similar between the groups simvastatin 80 and simvastatin 10/ezetimibe (27% ± 31% and 30% ± 29%, respectively, p = 0.75). The simvastatin 80 group presented an increase in FMV from 8.4% ± 4.3% at baseline to 11% ± 4.2% after 8 weeks (p = 0.02). Similarly, the group simvastatin 10/ezetimibe showed improvement in FMV from 7.3% ± 3.9% to 12% ± 4.4% (p = 0.001). The placebo group showed no variation in LDL-cholesterol level or endothelial function. Conclusion: The improvement in endothelial function with statin seems to depend more on a reduction in LDL-cholesterol levels, independent of the dose of statin administered, than on pleiotropic mechanisms.

Resumo Fundamento: O efeito das estatinas na função endotelial em seres humanos permanece em discussão. Particularmente, ainda carece resposta se a melhora na função endotelial deve-se à redução do LDL-colesterol ou a um efeito pleiotrópico arterial. Objetivo: Testar a hipótese de que a modulação da função endotelial promovida por estatinas é prioritariamente mediada pelo grau de redução do LDL-colesterol, independente da dose de estatina utilizada. Métodos: Ensaio clínico randomizado com dois grupos de tratamento hipolipemiante (16 pacientes/cada) e um grupo placebo (14 pacientes). Os dois grupos ativos foram desenhados para promover graus semelhantes de redução de LDL-colesterol: o primeiro utilizou estatina em alta dose (80 mg, grupo sinvastatina 80) e o segundo em baixa dose (10 mg) associada a ezetimiba (10 mg, grupo sinvastatina 10/ezetimiba) para otimizar o efeito hipolipemiante. A função endotelial foi analisada pela vasodilatação mediada por fluxo (VMF) antes e após 8 semanas de tratamento. Resultados: A redução no LDL-colesterol foi semelhante entre os grupos sinvastatina 80 e sinvastatina 10/ezetimiba (27% ± 31% e 30% ± 29%, respectivamente, p = 0,75). O grupo sinvastatina 80 apresentou incremento da VMF de 8,4% ± 4,3% no basal para 11% ± 4,2% após 8 semanas (p = 0,02). Da mesma forma, o grupo sinvastatina 10/ezetimiba apresentou melhora da VMF de 7,3% ± 3,9% para 12% ± 4,4% (p = 0,001). O grupo placebo não apresentou variação no nível de LDL-colesterol ou da função endotelial. Conclusão: A melhora da função endotelial com uso de estatina parece depender mais da redução do LDL-colesterol, independente da dose de estatina utilizada, do que de mecanismos pleiotrópicos.

Renin-Angiotensin System Blockade Associated with Statin Improves Endothelial Function in Diabetics / Bloqueio do Sistema Renina-Angiotensina Associado a Estatina Melhora a Função Endotelial em Diabéticos

Abstract Background: Studies suggest that statins have pleiotropic effects, such as reduction in blood pressure, and improvement in endothelial function and vascular stiffness. Objective: To analyze if prior statin use influences the effect of renin-angiotensin-aldosterone system inhibitors on blood pressure, endothelial function, and vascular stiffness. Methods: Patients with diabetes and hypertension with office systolic blood pressure ≥ 130 mmHg and/or diastolic blood pressure ≥ 80 mmHg had their antihypertensive medications replaced by amlodipine during 6 weeks. They were then randomized to either benazepril or losartan for 12 additional weeks while continuing on amlodipine. Blood pressure (assessed with ambulatory blood pressure monitoring), endothelial function (brachial artery flow-mediated dilation), and vascular stiffness (pulse wave velocity) were evaluated before and after the combined treatment. In this study, a post hoc analysis was performed to compare patients who were or were not on statins (SU and NSU groups, respectively). Results: The SU group presented a greater reduction in the 24-hour systolic blood pressure (from 134 to 122 mmHg, p = 0.007), and in the brachial artery flow-mediated dilation (from 6.5 to 10.9%, p = 0.003) when compared with the NSU group (from 137 to 128 mmHg, p = 0.362, and from 7.5 to 8.3%, p = 0.820). There was no statistically significant difference in pulse wave velocity (SU group: from 9.95 to 9.90 m/s, p = 0.650; NSU group: from 10.65 to 11.05 m/s, p = 0.586). Conclusion: Combined use of statins, amlodipine, and renin-angiotensin-aldosterone system inhibitors improves the antihypertensive response and endothelial function in patients with hypertension and diabetes.

Resumo Fundamentos: Estudos sugerem que as estatinas possuem efeitos pleotrópicos, como melhora da função endotelial, da rigidez vascular e redução da pressão arterial. Objetivo: Analisar se o uso prévio de estatina influenciou o efeito sobre a pressão arterial, a função endotelial e a rigidez vascular de drogas inibidoras do sistema renina-angiotensina-aldosterona. Métodos: Pacientes hipertensos e diabéticos com pressão arterial de consultório sistólica ≥ 130 mmHg e/ou diastólica ≥ 80 mmHg tiveram suas medicações anti-hipertensivas substituídas por anlodipino durante 6 semanas. Em seguida, foram randomizados para associação de benazepril ou losartana por mais 12 semanas. Pressão arterial (através da monitorização ambulatorial da pressão arterial), função endotelial (dilatação mediada por fluxo da artéria braquial) e rigidez vascular (velocidade da onda de pulso) foram avaliados antes e após o tratamento combinado. Neste trabalho, uma análise post-hoc foi realizada para comparar pacientes que vinham (grupo CE) ou não (grupo SE) em uso de estatina. Resultados: O grupo CE apresentou maior redução na pressão arterial sistólica nas 24 horas (134 para 122 mmHg, p = 0,007) e na dilatação mediada por fluxo da artéria braquial (6,5 para 10,9%, p = 0,003) quando comparado com o grupo SE (137 para 128 mmHg, p = 0,362, e 7,5 para 8,3%, p = 0,820). Não houve diferença estatisticamente significante na velocidade de onda de pulso (grupo CE 9,95 para 9,90 m/s, p = 0,650 e grupo SE 10,65 para 11,05 m/s, p = 0,586). Conclusão: O uso combinado de estatinas, anlodipino e inibidores do sistema renina-angiotensina-aldosterona melhora a resposta anti-hipertensiva e a função endotelial em pacientes hipertensos e diabéticos.

Nebivolol reduces central blood pressure in stage I hypertensive patients: experimental single cohort study / Nebivolol reduz pressão arterial central em pacientes hipertensos estágio I: estudo experimental de coorte única

CONTEXT AND OBJECTIVES: Assessment of central blood pressure (BP) has grown substantially over recent years because evidence has shown that central BP is more relevant to cardiovascular outcomes than peripheral BP. Thus, different classes of antihypertensive drugs have different effects on central BP despite similar reductions in brachial BP. The aim of this study was to investigate the effect of nebivolol, a β-blocker with vasodilator properties, on the biochemical and hemodynamic parameters of hypertensive patients. DESIGN AND SETTING: Experimental single cohort study conducted in the outpatient clinic of a university hospital. METHODS: Twenty-six patients were recruited. All of them underwent biochemical and hemodynamic evaluation (BP, heart rate (HR), central BP and augmentation index) before and after 3 months of using nebivolol. RESULTS: 88.5% of the patients were male; their mean age was 49.7 ± 9.3 years and most of them were overweight (29.6 ± 3.1 kg/m2) with large abdominal waist (102.1 ± 7.2 cm). There were significant decreases in peripheral systolic BP (P = 0.0020), diastolic BP (P = 0.0049), HR (P < 0.0001) and central BP (129.9 ± 12.3 versus 122.3 ± 10.3 mmHg; P = 0.0083) after treatment, in comparison with the baseline values. There was no statistical difference in the augmentation index or in the biochemical parameters, from before to after the treatment. CONCLUSIONS: Nebivolol use seems to be associated with significant reduction of central BP in stage I hypertensive patients, in addition to reductions in brachial systolic and diastolic BP. .

CONTEXTO E OBJETIVOS: A avaliação da pressão arterial central (PAc) tem crescido substancialmente nos últimos anos porque as evidências mostraram que PAc central é mais relevante para os desfechos cardiovasculares do que pressão arterial (PA) periférica. Assim, diferentes classes de anti-hipertensivos têm efeitos diferentes sobre PAc apesar de reduções semelhantes na PA braquial. O objetivo foi investigar o efeito do nebivolol, β-bloqueador com propriedades vasodilatadoras, nos parâmetros bioquímicos e hemodinâmicos de pacientes hipertensos. TIPO DE ESTUDO E LOCAL: Estudo de coorte única experimental realizado em ambulatório de hospital universitário. MÉTODOS: Todos os 26 pacientes recrutados foram submetidos à avaliação bioquímica e hemodinâmica (PA, frequência cardíaca, FC, PAc, augmentation index) antes e após três meses usando nebivolol. RESULTADOS: 88,5% dos indivíduos eram do sexo masculino, com média de idade de 49,7 ± 9,3 anos, predominância de sobrepeso (29,6 ± 3,1 kg/m2) e aumento da cintura abdominal (102,1 ± 7,2 cm). Houve diminuição significativa da PA sistólica periférica (P = 0,0020) e diastólica (P = 0,0049), da FC (P < 0,0001) e da PAc (129,9 ± 12,3 x 122,3 ± 10,3 mmHg, P = 0,0083) após o tratamento em comparação aos valores basais. Não houve diferença no augmentation index, nem nos parâmetros bioquímicos antes e após o período de tratamento. CONCLUSÕES: O uso de nebivolol parece estar associado à redução significativa da PAc em hipertensos estágio 1, além da redução da pressão sistólica e diastólica braquial. .

Função endotelial vascular em pacientes com fluxo coronário lento e os efeitos do nebivolol / Vascular endothelial function in patients with coronary slow flow and the effects of nebivolol

FUNDAMENTO: A função endotelial braquial tem sido associada ao fluxo lento coronário (FLC). O aumento do fluxo sanguíneo para a artéria braquial faz com que o endotélio libere óxido nítrico (ON), com subsequente vasodilatação. Além de sua atividade com betabloqueador, o nebivolol provoca vasodilatação, aumentando a liberação endotelial de ON. OBJETIVO: Avaliar os efeitos do nebivolol na função endotelial vascular em pacientes com FLC. MÉTODOS: 46 pacientes com FLC e 23 indivíduos com artérias coronárias epicárdicas normais foram examinados com ecocardiografia transtorácica e ultrassonografia da artéria braquial. Os pacientes foram reavaliados dois meses após o tratamento com aspirina ou aspirina e nebivolol. RESULTADOS: Os pacientes com FLC apresentaram maior índice de massa corporal (26,5 ± 3,3 vs. 23,8 ± 2,8, p < 0,001), tempo de relaxamento isovolumétrico (TRIV) de influxo mitral (114,9 ± 18,0 vs. 95,0 ± 22,0 mseg, p < 0,001), menor fração de ejeção do ventrículo esquerdo (FEVE) (63,5 ± 3,1 por cento vs. 65,4 ± 2,2, p = 0,009), colesterol HDL (39,4 ± 8,5 vs. 45,8 ± 7,7 mg/dL, p = 0,003) e dilatação fluxo-mediada da artéria braquial (DFM) (6,1 ± 3,9 por cento vs. 17,6 ± 4,5 por cento, p <0,001). Houve correlações significativas entre a DFM e a presença de FLC (r = 0,800, p < 0,001) e o colesterol HDL (r = 0,349, p = 0,003). Dos pacientes com FLC, apesar de os valores médios de DFM em pré-tratamento terem sido semelhantes (6,1 ± 4,3 por cento vs. 6,0 ± ,6 por cento, p = 0,917), em comparação com a DFM do grupo em pós-tratamento apenas com aspirina, a DFM apresentou valores significativamente maiores do que os pacientes tratados com aspirina e nebivolol (6,0 ± 3,5 por cento vs. 8,0 ± 2,9 por cento, p = 0,047). Constatou-se que o tratamento com nebivolol está associado a um significativo aumento na DFM (6,0 ± 3,6 a 8,0 ± 2,9 por cento, p = 0,030), ao passo que o tratamento apenas com aspirina não apresentou a mesma associação. CONCLUSÃO: A função endotelial pode ser comprometida nas artérias coronárias e braquiais em pacientes com FLC, e o nebivolol pode ser eficaz na melhora da função endotelial em pacientes com FLC.

BACKGROUND: Brachial endothelial function has been associated with coronary slow flow (CSF). Increasing blood flow to brachial artery provokes endothelium to release nitric oxide (NO) with subsequent vasodilatation. Besides its β1-blocker activity, nebivolol causes vasodilatation by increasing endothelial NO release. OBJECTIVE: To assess the effects of nebivolol on vascular endothelial function in patients with CSF. METHODS: Forty-six patients with CSF and 23 individuals with normal epicardial coronary arteries were examined with transthoracic echocardiography and brachial artery ultrasonography. The patients were reevaluated two months after treatment with aspirin or aspirin plus nebivolol. RESULTS: Patients with CSF had higher body mass index (26.5 ± 3.3 vs. 23.8 ± 2.8, p < 0.001), mitral inflow isovolumetric relaxation time (IVRT) (114.9 ± 18.0 vs. 95.0 ± 22.0 msec, p < 0.001) and lower left ventricular ejection fraction (LVEF) (63.5 ± 3.1 percent vs. 65.4 ± 2.2, p = 0.009), HDL-cholesterol (39.4 ± 8.5 vs. 45.8 ± 7.7 mg/dL, p = 0.003) and brachial flow-mediated dilatation (FMD) (6.1 ± 3.9 percent vs. 17.6 ± 4.5 percent, p < 0.001). There were significant correlations between FMD and the presence of CSF (r = 0.800, p < 0.001) and HDL-cholesterol (r = 0.349, p = 0.003). Among Patients with CSF, although pretreatment mean FMD values were similar (6.1 ± 4.3 percent vs. 6.0 ± ,6 percent, p = 0.917) compared to aspirin alone group, posttreatment FMD was significantly higher in patients treated with aspirin plus nebivolol (6.0 ± 3.5 percent vs. 8.0 ± 2.9 percent, p = 0.047). Treatment with nebivolol was associated with a significant increase in FMD (6.0 ± 3.6 to 8.0 ± 2.9 percent, p = 0.030) whereas treatment with aspirin alone was not. CONCLUSION: Endothelial function may be impaired in both coronary and brachial arteries in patients with CSF and nebivolol may be effective in the improvement of endothelial function in patients with CSF.

Estudo da reatividade vascular em portadores de HIV com e sem uso de inibidor de protease / Study of vascular reactivity in HIV patients whether or not receiving protease inhibitor

FUNDAMENTO: Considerando o alto número de pacientes infectados por HIV em uso de antirretrovirais, evoluindo com alteração da função endotelial e aterotrombose, levando ao alto custo médico social, é importante identificar mecanismos fisiopatológicos envolvidos com a função endotelial em portadores de HIV, para que, precocemente, possamos intervir e evitar a progressão da doença. OBJETIVO: Avaliar a função endotelial pela vasodilatação endotélio dependente e independente em pacientes HIV positivo e em grupo controle. MÉTODOS: O estudo avaliou 27 pacientes HIV positivo e 16 do grupo controle. A avaliação da função endotelial foi realizada por meio da vasodilatação da artéria braquial endotélio dependente (hiperemia reativa) e independente (nitroglicerina SL). RESULTADOS: Pacientes HIV positivo em uso de inibidor de protease (IP) apresentaram vasodilatação endotélio independente significativamente menor que os subgrupos HIV negativo (p = 0,020) e HIV positivo sem uso de IP (p = 0,034). A variação do diâmetro da artéria braquial durante hiperemia reativa não apresentou significância estatística em qualquer subgrupo. A análise de regressão linear múltipla mostrou que apenas o IP estava associado ao delta relativo da reatividade braquial pelo vasodilatador, nos pacientes HIV positivo, aos 60 e 90 segundos. CONCLUSÃO: Os pacientes HIV positivo em uso de IP apresentam disfunção endotélio independente quando comparados a pacientes HIV positivo que não fazem uso de IP e a um grupo controle.

BACKGROUND: A great number of HIV-infected patients using antiretroviral drugs develop endothelial dysfunction and atherothrombosis, which lead to a high medical and social burden. Thus, it is important to identify pathophysiological mechanisms involved with the endothelial function in these patients, so that early intervention can be made to avoid disease progression. OBJECTIVE: To evaluate endothelial function using endothelium-dependent and independent vasodilation in HIV-positive patients and in a control group. METHODS: A total of 27 HIV-positive patients and 16 controls were evaluated. Endothelium-dependent (reactive hyperemia) and independent (SL nitroglycerine) vasodilation of the brachial artery was used to evaluate the endothelial function. RESULTS: HIV-positive patients receiving protease inhibitors (PI) showed significantly lower endothelium-independent vasodilation than the HIV-negative (p=0.020) and HIV-positive without PI (p=0.034) subgroups. The change in brachial artery diameter during active hyperemia was not statistically significant in any subgroup. Multiple linear regression analysis showed that only PI was associated with the relative delta of brachial reactivity to vasodilator in HIV-positive patients at 60s and 90s. CONCLUSION: HIV-positive patients receiving PI presented endothelium-independent dysfunction when compared to HIV-positive patients not receiving PI and to the control group.

Clinical Effects of Calcium Channel Blocker and Angiotensin Converting Enzyme Inhibitor on Endothelial Function and Arterial Stiffness in Patients with Angina Pectoris

To evaluate the effects of calcium channel blocker (CCB) and angiotensin converting enzyme inhibitor (ACEI) on endothelial function and arterial stiffness in stable angina pectoris (SAP), 87 patients with SAP (57.6+/-10.0 yr, 52 males) were divided into two groups; CCB group (group I: n=44, 57.9+/-9.7 yr, 23 males) vs. CCB plus ACEI group (group II: n=43, 57.2+/-10.5 yr, 29 males). Flow mediated vasodilation (FMD) of the brachial artery, pulse wave velocity (PWV), urinary albumin excretion (UAE), and high sensitivity C-reactive protein (hsCRP) were compared. FMD, PWV, UAE, and hsCRP were not different between the groups at baseline. After 6 months of treatment, FMD were significantly improved in group II (7.5+/-3.7 to 8.8+/-2.7%, p<0.001), but not in group I (7.9+/-2.7 to 8.2+/-2.8%, p=0.535). Brachial-ankle PWV were significantly improved in both groups (1,621.3+/-279.4 to 1,512.1+/-225.0 cm/sec in group I, p<0.001, 1,586.8+/-278.5 to 1,434.5+/-200.5 cm/sec in group II, p<0.001). However, heart-femoral PWV were significantly improved (1,025.7+/-145.1 to 946.2+/-112.2 cm/sec, p<0.001) and UAE were significantly decreased (20.19+/-29.92 to 13.03+/-16.42 mg/g Cr, p=0.019) in group II only. In conclusion, combination therapy with CCB and ACEI improves endothelial function, arterial stiffness, and UAE than CCB mono-therapy more effectively in patients with SAP.

Atorvastatin improves arterial stiffness in normotensive normolipidaemic persons with type 2 diabetes.

Increased arterial stiffness is an independent predictor of cardiovascular disease and mortality in middle-aged and olderadults. We measured arterial stiffness by pulse wave velocity (PWV)in brachial-ankle segments by automated oscillometry in 71 normotensive and normolipidaemic subjects with type 2 diabetes (40 males and 31 females). 57 patients (whose baPWV was more than 1400 cm/second) were randomised into two groups, group A (n=29) were given 10 mg atorvastatin daily for 6 months and group B (n=28) were given placebo. After 6 months, atorvastatin group had significant improvement in brachial-ankle pulse wave velocity (baPWV) (1712.03 +/- 349.9 cm/second versus 1558.81 +/- 303.26 cm/ second, p< 0.05). Though the placebo group showed some improvement (1692.03 +/- 425.15 cm/second versus 1636.78 +/- 425.1 cm/second) it was not statistically significant. Despite correlation was noted between baPWV and systolic blood pressure (SBP), there was no significant correlation between the mean baPWV and duration of diabetes, body mass index (BMI), waist circumference, waist-hip ratio (WHR), waist to height ratio (WHtR), glycated haemoglobin (HbA1c), LDL, HDL cholesterol and spot urine albumin creatinine ratio (ACR) at the baseline. The decrement of LDL-cholesterol is correlated with the decrement of the baPWV in the atorvastatin group only (p<0.01).

Use of vascular Doppler ultrasound to detect acute estradiol vascular effect in postmenopausal women

OBJECTIVES: To report on a simple practical test for assessing acute estradiol vascular effects on healthy and unhealthy postmenopausal women. INTRODUCTION: Estradiol acts in the endothelium to promote vasodilatation through genomic and non-genomic mechanisms, but its vascular action may be impaired in diabetes mellitus, hypertension, smoking and obesity. METHODS: Nineteen postmenopausal women (nine healthy and 10 with two or more of the above factors) of similar age and time since menopause were examined with vascular Doppler ultrasound. Resistance indexes and systolic and diastolic flow velocities were determined for the brachial and internal carotid arteries at baseline and 20 minutes after administration of a nasal estradiol formulation, available on the market, which reaches 1,200-1,500 pg/ml in the serum in 10-30 minutes. Estradiol blood levels were measured at 30 minutes. RESULTS: The carotid resistance index increased 14.2 percent (vasoconstriction) in the unhealthy group after estradiol, from a mean ± S.E. of 0.56 ± 0.016 at baseline to 0.64 ± 0.05 (p=0.033), and remained unchanged in healthy women. Brachial diastolic flow velocity increased 19.7 percent (vasodilatation) in healthy women, from 16.2 ± 1.93 to 19.4 ± 0.64 cm/s (p=0.046), and did not change in the unhealthy subjects. Estradiol levels were similar in both groups. DISCUSSION: Healthy postmenopausal women showed brachial vasodilatation while unhealthy postmenopausal women displayed vasoconstriction at the carotid artery. Vascular responses to estradiol were divergent between the groups. CONCLUSIONS: The acute estradiol test, coupled with Doppler ultrasound, seemed to be able to differentiate women with normal and abnormal endothelial function in a simple, non-invasive manner.

OBJETIVO: Descrever um teste simples e prático para avaliar o efeito vascular agudo do estradiol em mulheres saudáveis e não-saudáveis na menopausa. INTRODUÇÃO: O estradiol atua no endotélio promovendo vasodilatação através de mecanismos genômicos e não-genômicos e esta ação pode estar prejudicada em morbidades como diabetes mellitus, hipertensão, tabagismo e obesidade. MÉTODOS: Dezenove mulheres na pós-menopausa (9 saudáveis e 10 com dois ou mais dos fatores acima), com idade e tempo de menopausa semelhantes foram examinadas por Doppler vascular. O índice de resistência e as velocidades de fluxo sistólico e diastólico foram medidos nas artérias braquial e carótida, em condições basais e 20 min após a administração de uma preparação nasal de estradiol, disponível comercialmente, que atinge 1200 a 1500 pg/ml no soro, entre 10 e 30 min após a aplicação. Os níveis séricos de estradiol foram determinados 30 min após a aplicação nasal. RESULTADOS: O índice de resistência da artéria carótida aumentou em 14,2 por cento (vasoconstricção) após o estradiol no grupo não-saudável, partindo da média ± SE de 0,56 ± 0,016 para 0,64 ± 0,05 (p=0,033) e não se modificou nas mulheres saudáveis. A velocidade de fluxo diastólico da artéria braquial aumentou 19,7 por cento (vasodilatação) nas mulheres saudáveis, partindo de 16,2 ± 1,93 para 19,4 ± 0,64 cm/s (p=0,046) e não apresentou alteração nas não saudáveis. Os níveis de estradiol foram semelhantes nos dois grupos. DISCUSSÃO: Nas mulheres saudáveis na menopausa houve vasodilatação da artéria braquial e nas não-saudáveis vasoconstricção na artéria carótida. A resposta vascular ao estradiol foi divergente entre os grupos estudados. CONCLUSÃO: O teste com estradiol agudo, associado ao Doppler vascular, parecem diferenciar, de forma simples e não-invasiva, mulheres com função endotelial normal e anormal.

Noninvasive evaluation of endothelial function and arterial mechanics in overweight adolescents.

OBJECTIVE: To evaluate endothelial function and arterial mechanics in apparently healthy overweight adolescents. Design: Analytical observational study. SETTING: Tertiary hospital. METHODS: 40 asymptomatic, normotensive and non-smoking adolescents (11 to 18 years old) were evaluated. Of these 20 were overweight or obese as per International Obesity Task Force criteria while 20 were controls. High resolution ultrasonography was performed to measure flow mediated and Glyceryltrinitrate induced dilation in brachial artery, and arterial mechanics in common carotid artery. RESULTS: Overweight adolescents had significantly lower ratio of flow mediated dilation to Glyceryltrinitrate mediated dilation (0.40 plusminus 0.41 versus 0.61 plusminus 0.17; P = 0.039). On age and sex adjusted multiple regression analysis, the ratio of flow mediated to Glyceryltrinitrate mediated dilation had a significant negative association with body mass index (P = 0.012) and mean skin fold thickness (P = 0.011). However, for mean skin fold thickness, flow mediated dilation also had a significant negative association (P = 0.027). None of the measures of arterial mechanics were significantly different amongst overweights and controls, or significantly associated with either body mass index or mean skin fold thickness. CONCLUSION: Endothelial function can be mildly impaired in apparently healthy adolescents who are overweight (assessed by body mass index) or adipose (assessed by skin fold thickness). The use of overweight for screening adolescents likely to develop coronary artery disease is therefore justified. Skin fold thickness is a better indicator than Body Mass Index for predicting endothelial function.

Terminalia arjuna reverses impaired endothelial function in chronic smokers.

BACKGROUND: Smoking, largely through increased oxidative stress, causes endothelial dysfunction which is an early key event in atherosclerosis. Smoking cessation and antioxidant vitamin therapy are shown to have beneficial role by restoring altered endothelial physiology. The present study was aimed to determine whether Terminalia arjuna, an Indian medicinal plant with potent antioxidant constituents, would improve endothelial dysfunction in smokers. METHODS AND RESULTS: Eighteen healthy male smokers (age 28.16+/-9.45 years) and equal number of age-matched non-smoker controls participated in the study. The baseline brachial artery reactivity studies were performed using high frequency ultrasound according to standard protocol under identical conditions to determine endothelium-dependent, flow-mediated dilation and endothelium-independent nitroglycerine-mediated dilation. The two groups were matched regarding age, body mass index, blood pressure, serum cholesterol, mean resting vessel diameters and post-occlusion flow velocities (all p=NS). While flow-mediated dilation was significantly impaired amongst smokers compared to controls (4.71+/-2.22 v. 11.75+/-5.94%, p <0.005), the nitroglycerine-mediated dilation was similar in the two groups (20.35+/-3.89 v. 19.68+/-3.74%, p=NS). Subsequently the smokers were given Terminalia arjuna (500 mg q8h) or matching placebo randomly in a double blind cross-over design for two weeks each, followed by repetition of brachial artery reactivity studies to determine various parameters including flow-mediated dilation after each period. There was no significant difference as regards vessel diameter and flow velocities between the two therapies. However, the flow-mediated dilation showed significant improvement from baseline values after Terrminalia arjuna therapy but not with placebo (9.31+/-3.74 v. 5.17+/-2.42%, p <0.005). CONCLUSIONS: Smokers have impaired endothelium-dependent but normal endothelium-independent vasodilation as determined by brachial artery reactivity studies. Further, Terrminalia arjuna therapy for two weeks leads to significant regression of this endothelial abnormality amongst smokers.