Microvascular Reactivity in Hypertensive Patients with High Body Adiposity. / Estudo da Reatividade Microvascular em Pacientes Hipertensos com Adiposidade Corporal Elevada.

BACKGROUND: Several anthropometric indexes have been proposed to determine the association between overweight and cardiovascular risk factors. OBJECTIVE: To evaluate the relationship between body adiposity and microvascular reactivity in hypertensive patients under antihypertensive therapy. METHODS: Treated hypertensive patients aged 40 to 70 were submitted to evaluation of anthropometric indexes: conicity (CI), body adiposity (BAI), visceral adiposity (VAI) and waist-to-height ratio (WHtR). Participants were divided by the terciles of fat percentage (%F) obtained by bioelectrical impedance. The patients underwent microvascular reactivity test (Laser Speckle Contrast Image) and pulse wave velocity (PWV) measurement. The p value <0.05 was considered statistically significant. RESULTS: The variation of the area under the curve (AUC) of the skin perfusion was lower in the upper tercile (97±57% vs. 67±36%; p=0.027). %F showed significant correlation with WHtR (r=0.77; p<0.001), VAI (r=0.41; p=0.018), CI (r=0.60; p<0.001), BAI (r=0.65; p<0.001) in men and only with WHtR (r=0.55; p<0.001) and BAI (r=0.60; p<0.001) in women. In linear regression, AUC was independently associated with %F (ß=-3.15; p=0.04) in women and with blood glucose (ß=-1.15; p=0.02) in men. There was no difference in PWV measurements. CONCLUSION: Anthropometric indices were more associated with %F in men. Higher body adiposity was associated with lower microvascular reactivity, which was more evident in women. There was no difference in arterial stiffness, which may have been influenced by antihypertensive treatment.

FUNDAMENTO: Diversos índices antropométricos têm sido propostos para determinar a associação entre excesso de peso e fatores de risco cardiovascular. OBJETIVO: Avaliar a relação entre adiposidade corporal e reatividade microvascular em pacientes hipertensos sob terapia anti-hipertensiva. MÉTODOS: Pacientes hipertensos tratados de 40 a 70 anos foram submetidos à avaliação de índices antropométricos: conicidade (IC), adiposidade corporal (IAC), adiposidade visceral (IAV) e relação cintura-estatura (RCE). Os participantes foram divididos pelos tercis de percentual de gordura (%G) obtido pela bioimpedância elétrica (BIA) e submetidos a teste de reatividade microvascular (laser speckle contrast image), medida da velocidade da onda de pulso (VOP). O valor de p < 0,05 foi considerado estatisticamente significativo. RESULTADOS: A variação da área sob a curva (ASC) da perfusão cutânea foi inferior no tercil superior (97 ± 57% vs. 67 ± 36%; p = 0,027). O %G apresentou correlação significativa com RCE (r = 0,77; p < 0,001), IAV (r = 0,41; p = 0,018), IC (r = 0,60; p < 0,001) e IAC (r = 0,65; p < 0,001) nos homens e somente com RCE (r = 0,55; p < 0,001) e IAC (r = 0,60; p < 0,001) nas mulheres. Na regressão linear, a ASC mostrou associação independente com o %G (ß =­3,15; p = 0,04) nas mulheres e com a glicemia (ß = ­1,15; p = 0,02) nos homens. Não houve diferença nas medidas de VOP. CONCLUSÃO: Os índices antropométricos de obesidade foram mais associados ao %G nos homens. A maior adiposidade corporal foi relacionada com menor reatividade microvascular, o que foi mais evidente nas mulheres. Não houve diferença na rigidez arterial, o que pode ter sido influenciado pelo tratamento anti-hipertensivo.

Estudo da Reatividade Microvascular em Pacientes Hipertensos com Adiposidade Corporal Elevada / Microvascular Reactivity in Hypertensive Patients with High Body Adiposity

Resumo Fundamento: Diversos índices antropométricos têm sido propostos para determinar a associação entre excesso de peso e fatores de risco cardiovascular. Objetivo: Avaliar a relação entre adiposidade corporal e reatividade microvascular em pacientes hipertensos sob terapia anti-hipertensiva. Métodos: Pacientes hipertensos tratados de 40 a 70 anos foram submetidos à avaliação de índices antropométricos: conicidade (IC), adiposidade corporal (IAC), adiposidade visceral (IAV) e relação cintura-estatura (RCE). Os participantes foram divididos pelos tercis de percentual de gordura (%G) obtido pela bioimpedância elétrica (BIA) e submetidos a teste de reatividade microvascular (laser speckle contrast image), medida da velocidade da onda de pulso (VOP). O valor de p < 0,05 foi considerado estatisticamente significativo. Resultados: A variação da área sob a curva (ASC) da perfusão cutânea foi inferior no tercil superior (97 ± 57% vs. 67 ± 36%; p = 0,027). O %G apresentou correlação significativa com RCE (r = 0,77; p < 0,001), IAV (r = 0,41; p = 0,018), IC (r = 0,60; p < 0,001) e IAC (r = 0,65; p < 0,001) nos homens e somente com RCE (r = 0,55; p < 0,001) e IAC (r = 0,60; p < 0,001) nas mulheres. Na regressão linear, a ASC mostrou associação independente com o %G (β =-3,15; p = 0,04) nas mulheres e com a glicemia (β = -1,15; p = 0,02) nos homens. Não houve diferença nas medidas de VOP. Conclusão: Os índices antropométricos de obesidade foram mais associados ao %G nos homens. A maior adiposidade corporal foi relacionada com menor reatividade microvascular, o que foi mais evidente nas mulheres. Não houve diferença na rigidez arterial, o que pode ter sido influenciado pelo tratamento anti-hipertensivo.

Abstract Background: Several anthropometric indexes have been proposed to determine the association between overweight and cardiovascular risk factors. Objective: To evaluate the relationship between body adiposity and microvascular reactivity in hypertensive patients under antihypertensive therapy. Methods: Treated hypertensive patients aged 40 to 70 were submitted to evaluation of anthropometric indexes: conicity (CI), body adiposity (BAI), visceral adiposity (VAI) and waist-to-height ratio (WHtR). Participants were divided by the terciles of fat percentage (%F) obtained by bioelectrical impedance. The patients underwent microvascular reactivity test (Laser Speckle Contrast Image) and pulse wave velocity (PWV) measurement. The p value <0.05 was considered statistically significant. Results: The variation of the area under the curve (AUC) of the skin perfusion was lower in the upper tercile (97±57% vs. 67±36%; p=0.027). %F showed significant correlation with WHtR (r=0.77; p<0.001), VAI (r=0.41; p=0.018), CI (r=0.60; p<0.001), BAI (r=0.65; p<0.001) in men and only with WHtR (r=0.55; p<0.001) and BAI (r=0.60; p<0.001) in women. In linear regression, AUC was independently associated with %F (β=−3.15; p=0.04) in women and with blood glucose (β=−1.15; p=0.02) in men. There was no difference in PWV measurements. Conclusion: Anthropometric indices were more associated with %F in men. Higher body adiposity was associated with lower microvascular reactivity, which was more evident in women. There was no difference in arterial stiffness, which may have been influenced by antihypertensive treatment.

Endothelial dysfunction and pulse wave reflection in women with Polycystic Ovarian Syndrome / Disfunção endotelial e reflexão de ondas de pulso em mulheres com Síndrome do Ovário Policístico

Background: Patients with polycystic ovarian syndrome (PCOS) have an increased prevalence of metabolic syndrome and traditional atherosclerotic risk factors, such as dyslipidemia, diabetes and hypertension. Endothelial function and vascular stiffness are surrogate markers of early atherosclerosis, able to predict cardiovascular events. Objective: To compare endothelial function and pulse wave reflection between women with PCOS and healthy controls. Methods: Observational and cross-sectional study that included women with PCOS, age between 18 and 40 years-old and body mass index between 25.0 and 35.0 kg/m2, and healthy controls. Rotterdan criteria was used to diagnose PCOS. Subjects underwent clinical and anthropometric evaluation, laboratory and hormonal assays and imaging tests to measure pulse wave velocity (PWV), augmentation index (AIx) and brachial artery flow-mediated vasodilation (FMD). Kolmogorov-Smirnov test showed normal distribution of most parameters. Unpaired Student t-test was used with significance level established at p < 0.05.Results: A total of 52 patients were included, 29 (56%) in PCOS group and 23 (44%) in control group. Clinical and laboratory parameters were similar between the groups. Women with PCOS had lower FMD (8.8 ± 1.0 vs 12.8 ± 1.2%, p = 0.021); PWV and AIx were similar between the groups (7.5 ± 0.2 vs 7.5 ± 0.3 m/s, p = 0.671 and 21.0 ± 1 vs. 20 ± 2%, p = 0.716, respectively). In the PCOS group, women with higher testosterone levels had higher AIx (25 ± 2 vs. 17 ± 3%, p = 0.045). Conclusions: PCOS women had endothelial dysfunction and those with higher testosterone levels had higher pulse wave reflection as compared with controls

The Role of Renin-Angiotensin-Aldosterone System and Its New Components in Arterial Stiffness and Vascular Aging.

Many cardiovascular diseases present renin-angiotensin-aldosterone system (RAAS) hyperactivity as an important pathophysiological mechanism to be target in the therapeutic approaches. Moreover, arterial stiffness is currently considered as a new independent risk factor for cardiovascular disease in different clinical conditions, including hypertension and chronic kidney disease. In fact, excessive stimulation of angiotensin type 1 (AT1) receptors, as well as mineralocorticoid receptors, results in cellular growth, oxidative stress and vascular inflammation, which may lead to arterial stiffness and accelerate the process of vascular aging. In the last decades, a vasoprotective axis of the RAAS has been discovered, and now it is well established that new components with antioxidant and anti-inflammatory properties play important roles promoting vasodilation, natriuresis and reducing collagen deposition, thus attenuating arterial stiffness and improving endothelial function. In this review, we will focus on these pathophysiological mechanisms and the relevance of RAAS inhibition by different strategies to increase arterial compliance and to decelerate vascular aging.

Twenty-four hour Blood Pressure in Obese Patients with Moderate-to-Severe Obstructive Sleep Apnea / Pressão Arterial nas 24 horas em Obesos com Apneia Obstrutiva do Sono Moderada à Grave

Abstract Background: Obesity, systemic arterial hypertension (SAH) and obstructive sleep apnea (OSA) are closely related. Up to 70% of patients with OSA may be asymptomatic, and there is evidence that these patients have cardiovascular disease, especially nocturnal SAH. Objectives: The aim of this study was to evaluate 24-hour blood pressure circadian variation in asymptomatic, obese individuals with moderate-to-severe OSA and compare it with that in individuals with mild OSA or without OSA. Methods: Eighty-six obese subjects aged between 30 and 55 years (BMI 30-39 kg/m2), with casual blood pressure < 140/90 mmHg and without comorbidities were recruited. Eighty-one patients underwent clinical and anthropometric assessment, ambulatory blood pressure monitoring (ABPM), and Watch-PAT. Participants were divided into two groups, based on the apnea-hypopnea index (AHI): group 1, with AHI < 15 events/hour, and group 2 with AHI ≥ 15 events/hour. Results: Compared with group 1, group 2 had higher neck circumference and waist-hip circumference (40.5 ± 3.2 cm vs. 38.0 ± 3.7 cm, p = 0.002, and 0.94 ± 0.05 vs. 0.89 ± 0.05, p = 0.001, respectively), higher systolic and diastolic blood pressure measured by the 24-h ABPM (122 ± 6 vs 118 ± 8 mmHg, p = 0.014, and 78 ± 6 vs 73 ± 7 mmHg, p = 0.008, respectively), and higher nocturnal diastolic pressure load (44,6 ± 25,9% vs 31,3 ± 27,3%, p = 0,041). Moreover, there was a positive correlation between nocturnal diastolic blood pressure and AHI (r = 0.43, p < 0.05). Conclusions: Asymptomatic obese subjects with moderate-to-severe OSA have higher systolic and diastolic blood pressure at 24 hours compared with those with absent / mild OSA, despite normal casual blood pressure between the groups. These results indicate that ABPM may be useful in the evaluation of asymptomatic obese patients with moderate-to-severe OSA.

Resumo Fundamentos: Obesidade, hipertensão arterial sistêmica (HAS) e apneia obstrutiva do sono (AOS) estão intimamente relacionados. Até 70% dos pacientes com AOS podem ser assintomáticos e há evidências que eles apresentam alterações cardiovasculares, em especial HAS noturna. Objetivos: O objetivo deste estudo foi avaliar o comportamento da pressão arterial nas 24 horas em indivíduos obesos assintomáticos com AOS moderada/grave comparando àqueles com AOS leve/ausente. Métodos: Foram selecionados 86 pacientes entre 30 e 55 anos, obesos (IMC 30-39,9 kg/m2), com pressão arterial casual < 140/90 mmHg e sem comorbidades, dos quais 81 foram submetidos à avaliação clínica, medidas antropométricas, monitorização ambulatorial da pressão arterial (MAPA) e Watch-PAT. Os participantes do estudo foram divididos em dois grupos com base no índice de apneia-hipopneia (IAH): grupo 1 com IAH < 15 eventos/h e grupo 2 com IAH ≥ 15 eventos/h. Resultados: Em comparação ao grupo 1, o grupo 2 apresentou maior circunferência de pescoço e maior relação cintura-quadril (40,5 ± 3,2 vs 38,0 ± 3,7 cm, p = 0,002, e 0,94 ± 0,05 vs 0,89±0,05cm, p = 0,001, respectivamente), maiores pressões arteriais sistólica e diastólica na MAPA-24h (122 ± 6 vs 117 ± 8 mmHg, p = 0,014, e 78 ± 6 vs 73 ± 7 mmHg, p = 0,008, respectivamente), bem como maior carga pressórica diastólica noturna (44,6 ± 25,9% vs 31,3 ± 27,3%, p = 0,041). Além disso, houve correlação positiva entre pressão arterial diastólica noturna e IAH (r = 0,43, p < 0,05). Conclusões: Indivíduos obesos assintomáticos com AOS de moderada a grave apresentam maiores valores de PA sistólica e diastólica nas 24 horas em comparação àqueles com AOS ausente/leve, apesar da PA casual normal. Esses resultados indicam que a MAPA pode ser útil na avaliação de pacientes obesos assintomáticos com AOS de moderada à grave.

Twenty-four hour Blood Pressure in Obese Patients with Moderate-to-Severe Obstructive Sleep Apnea.

BACKGROUND: Obesity, systemic arterial hypertension (SAH) and obstructive sleep apnea (OSA) are closely related. Up to 70% of patients with OSA may be asymptomatic, and there is evidence that these patients have cardiovascular disease, especially nocturnal SAH. OBJECTIVES: The aim of this study was to evaluate 24-hour blood pressure circadian variation in asymptomatic, obese individuals with moderate-to-severe OSA and compare it with that in individuals with mild OSA or without OSA. METHODS: Eighty-six obese subjects aged between 30 and 55 years (BMI 30-39 kg/m2), with casual blood pressure < 140/90 mmHg and without comorbidities were recruited. Eighty-one patients underwent clinical and anthropometric assessment, ambulatory blood pressure monitoring (ABPM), and Watch-PAT. Participants were divided into two groups, based on the apnea-hypopnea index (AHI): group 1, with AHI < 15 events/hour, and group 2 with AHI ≥ 15 events/hour. RESULTS: Compared with group 1, group 2 had higher neck circumference and waist-hip circumference (40.5 ± 3.2 cm vs. 38.0 ± 3.7 cm, p = 0.002, and 0.94 ± 0.05 vs. 0.89 ± 0.05, p = 0.001, respectively), higher systolic and diastolic blood pressure measured by the 24-h ABPM (122 ± 6 vs 118 ± 8 mmHg, p = 0.014, and 78 ± 6 vs 73 ± 7 mmHg, p = 0.008, respectively), and higher nocturnal diastolic pressure load (44,6 ± 25,9% vs 31,3 ± 27,3%, p = 0,041). Moreover, there was a positive correlation between nocturnal diastolic blood pressure and AHI (r = 0.43, p < 0.05). CONCLUSIONS: Asymptomatic obese subjects with moderate-to-severe OSA have higher systolic and diastolic blood pressure at 24 hours compared with those with absent / mild OSA, despite normal casual blood pressure between the groups. These results indicate that ABPM may be useful in the evaluation of asymptomatic obese patients with moderate-to-severe OSA.

Oral magnesium supplementation improves endothelial function and attenuates subclinical atherosclerosis in thiazide-treated hypertensive women.

BACKGROUND: Epidemiological studies demonstrate an inverse association between serum magnesium and incidence of cardiovascular disease. Diuretics commonly cause hypomagneseamia. METHOD: We evaluated effects of magnesium supplementation on blood pressure (BP) and vascular function in thiazide-treated hypertensive women in a randomized, double-blind, clinical trial. Hypertensive women (40-65 years) on hydrochlorothiazide and mean 24-h BP at least 130/80 mmHg were divided into placebo and supplementation (magnesium chelate 600 mg/day) groups. Patients were evaluated for nutritional and biochemical parameters, office and ambulatory blood pressure monitoring, brachial flow-mediated dilatation (FMD), peripheral arterial tonometry, assessment of carotid intima-media thickness, central hemodynamic parameters and pulse wave velocity at inclusion and after 6-month follow-up. RESULTS: The magnesium group had a significant reduction in SBP (144 ±â€Š17 vs. 134 ±â€Š14 mmHg, P = 0.036) and DBP (88 ±â€Š9 vs. 81 ±â€Š8 mmHg, P = 0.005) at 6 months, without effect on plasma glucose, lipids, or arterial stiffness parameters. The placebo group showed a significant increase in carotid intima-media thickness (0.78 ±â€Š0.13 vs. 0.89 ±â€Š0.14 mm, P = 0.033) without change in the magnesium group (0.79 ±â€Š0.16 vs. 0.79 ±â€Š0.19 mm, P = 0.716) after 6 months. The magnesium group demonstrated a significant increase in variation of FMD vs. the placebo group (+3.7 ±â€Š2.1 vs. 2.4 ±â€Š1.2%, P = 0.015). There was a significant correlation between the intracellular magnesium variation and FMD (r = 0.44, P = 0.011). CONCLUSION: Magnesium supplementation was associated with better BP control, improved endothelial function and amelioration of subclinical atherosclerosis in these thiazide-treated hypertensive women.

Beneficial Effects of Dietary Nitrate on Endothelial Function and Blood Pressure Levels.

Poor eating habits may represent cardiovascular risk factors since high intake of fat and saturated fatty acids contributes to dyslipidemia, obesity, diabetes mellitus, and hypertension. Thus, nutritional interventions are recognized as important strategies for primary prevention of hypertension and as adjuvants to pharmacological therapies to reduce cardiovascular risk. The DASH (Dietary Approach to Stop Hypertension) plan is one of the most effective strategies for the prevention and nonpharmacological management of hypertension. The beneficial effects of DASH diet on blood pressure might be related to the high inorganic nitrate content of some food products included in this meal plan. The beetroot and other food plants considered as nitrate sources account for approximately 60-80% of the daily nitrate exposure in the western population. The increased levels of nitrite by nitrate intake seem to have beneficial effects in many of the physiological and clinical settings. Several clinical trials are being conducted to determine the broad therapeutic potential of increasing the bioavailability of nitrite in human health and disease, including studies related to vascular aging. In conclusion, the dietary inorganic nitrate seems to represent a promising complementary therapy to support hypertension treatment with benefits for cardiovascular health.

Alterações cardiometabólicas em mulheres hipertensas com obesidade abdominal / Cardiometabolic disorders in Hypertensive women with abdominal obesity

Fundamentos: Estudos mostram o aumento da circunferência abdominal como indicador relevante de riscocardiovascular (RCV) aumentado.Objetivo: Identificar alterações cardíacas estruturais e funcionais em mulheres hipertensas não diabéticas comobesidade abdominal (OA). Métodos: Estudo transversal com 120 mulheres hipertensas, de 40-65 anos, estratificadas em: grupo sem obesidadeabdominal (SOA, n=42) e com obesidade abdominal (COA, n=78), sendo circunferência abdominal < ou ≥88 cm, respectivamente. Realizou-se avaliação clínica, exames bioquímicos, ecoDopplercardiograma e ultrassonografia de carótida.Resultados: A média de idade foi 53±1 anos nos grupos. A pressão arterial (PA) sistólica, embora maior no grupo COA, não atingiu significância estatística (145±2mmHg vs. 140±2mmHg, p=0,098). Grupo COA apresentou maiorPA diastólica (90±1mmHg vs. 85±1mmHg, p <0,05), maior número de critérios (3,1±0,1 vs. 1,4±0,1, p<0,001) e prevalência de síndrome metabólica (62,8% vs. 11,9%, p<0,001). Apesar de glicemias normais, pacientes COA apresentaram índices mais altos de HOMA-IR (2,62±0,22 vs. 1,61±0,17 p<0,01) e HOMA-beta (358±57 vs. 200±22, p<0,05). Na avaliação ecocardiográfica, a função sistólica foi semelhante nos grupos, mas o grupo COA apresentou evidências de disfunção diastólica pelo Doppler tissular e prevalência maior de hipertrofia ventricular esquerda (29,2% vs. 2,4%), sem diferença entre a espessura médio-intimal da carótida.Conclusões: Nesta amostra de hipertensas não diabéticas, a obesidade abdominal foi associada com maiores níveis de pressão arterial diastólica, redução da sensibilidade à insulina e alterações cardíacas, especialmente hipertrofia ventricular esquerda e disfunção diastólica. Contudo, não houve evidência de aterosclerose carotídea subclínica nas hipertensas com e sem obesidade abdominal.

Background: Studies show increased waist circumference as a relevant indicator of increased cardiovascular risk (CVR). Objective: To identify structural and functional cardiac abnormalities in nondiabetic hypertensive women with abdominal obesity (AO). Methods: Cross-sectional study with 120 hypertensive women, aged 40-65, stratified into: group with no abdominal obesity (NAO,n=42) and with abdominal obesity (QAO, n=78), and waist circumference < or ≥88cm, respectively. Clinical evaluation, biochemical tests, Doppler echocardiography and carotid ultrasound were conducted. Results: Average age was 53±1 in the groups. Although the systolic blood pressure (BP) was higher in the WAO group, it did not reach statistical significance (145±2mmHg vs. 140±2mmHg, p=0.098). The WAO group had higher diastolic BP (90±1mmHg vs. 85±1mmHg, p<0.05), greater number of criteria (3.1±0.1 vs. 1.4±0.1, p<0.001) and prevalence of metabolic syndrome (62.8% vs.11.9%; p<0.001). Despite normal blood glucose levels, WAO patients had higher HOMA-IR levels (2.62±0.22 vs. 1.61±0.17 p<0.01) and HOMA-beta levels (358±57 vs. 200±22, p<0.05). In the echocardiographic evaluation, systolic function was similar in bothgroups, but the WAO group presented evidence of diastolic dysfunction by tissue Doppler and higher prevalence of left ventricular hypertrophy (29.2% vs. 2.4%), with no difference between the carotid artery intima-media thickness.Conclusions: In this sample of nondiabetic hypertensive women, abdominal obesity was associated with higher levels of diastolic blood pressure, reduced insulin sensitivity and cardiac issues, especially left ventricular hypertrophy and diastolic dysfunction.However, there was no evidence of subclinical carotid atherosclerosis in hypertensive patients with and without abdominal obesity.

As grandes artérias em foco: avaliação da rigidez arterial no paciente hipertenso / The large arteries in focus: assessment of arterial stiffness in the hypertensive patient

Evidências comprovam que a rigidez arterial apresenta uma forte correlação com lesões de órgãos-alvo e é um fator de risco para eventos cardiovasculares na população hipertensa,independente de outros fatores de risco mais conhecidos. Diversos mecanismos estão envolvidos na relação entre hipertensão e rigidez arterial, como envelhecimento, inflamação, alterações metabólicas e neuro-humorais. Estes mecanismos justificam a rigidez arterial como consequência, mas também com causa de elevação da pressão arterial, de acordo com alguns estudos clínicos e experimentais. A rigidez arterial pode ser avaliada de forma local, regional ou sistêmica. Entre as diversas formas, a medida da velocidade da onda de pulso (VOP) é considerada um preditor independente para morbidade e mortalidade cardiovascular em diversas populações. Particularmente, a VOP carótido-femoral tem o maior valor preditivo e possui valores de referência disponíveis, por isso é considerada o padrão-ouro para a medida da rigidez arterial aórtica ou central. Considerando que a VOP carótido-femoral é altamente dependente da idade e da pressão arterial, há uma série de limitações quando se define um ponto de corte fixo para toda a população. Além disso, a distância entre as artérias deve ser medida com muita precisão, pois pequenas diferenças podem influenciar o valor final da VOP. A rigidez arterial sistêmica pode ser avaliada indiretamente através da análise da onda de pulso aórtica derivada a partir da tonometria de aplanação da artéria radial. Todavia, a relação entre os parâmetros centrais obtidos e a rigidez arterial é complexa e, por isso, não devem ser interpretados isoladamente.

Evidence has shown that arterial stiffness is closely correlated with lesions of the target organs, and is a risk factor for cardiovascular events in the hypertensive population, independent of other more well-known risk factors. Various mechanisms are involved in the relationship between Hypertension and arterial stiffness, such as aging, inflammation, metabolic changes and neuro-humoral changes. These mechanisms explain arterial stiffness as a consequence, but also as the cause of increased blood pressure, according to some clinical and experimental studies. Arterial stiffness can be evaluated locally, regionally, or systemically. Among the various forms, the measurement of pulse wave velocity (PWV) is considered an independent predictor for cardiovascular morbidity and mortality in various populations. Carotid-femoral PWV, in particular, has the highest predictive value, and available reference values. For this reason, it is considered the gold standard for measuring aortic or central arterial stiffness. Considering that the carotid-femoral PWV is highly dependent on age and arterial pressure, there is a series of limitations when defining a fixed cut-off point for the whole population. Furthermore, the distance between the arteries should be measured very precisely, as small diferences can influence the final PW score. Systemic arterial stiffness can be evaluated indirectly, through the analysis of aortic pulse wave derived from radial artery applanation tonometry. However, the relationship between the central parameters obtained, and arterial stiffness,is complex, and should not be interpreted in isolation.

Altered vascular structure and wave reflection in hypertensive women with low magnesium levels.

Magnesium has been implicated in the pathogenesis of hypertension, but the role of its intracellular levels in cardiovascular diseases is not clear yet. We investigated the relationships of low concentrations of serum magnesium (sMg) and intracellular Mg (iMg) with clinical and vascular parameters. Thiazide-treated hypertensive women were separated into two groups according to lower (<2.0 mg/dL) or normal (≥2.0 mg/dL) sMg concentrations. The same patients were later divided according to lower (<3.75 mg/dL erythrocytes) and normal (≥3.75 mg/dL erythrocytes) iMg concentrations. Carotid ultrasound, radial applanation, and peripheral arterial tonometry were performed in all patients. Low sMg levels were associated with increased Framingham Risk Score (16% ± 3% vs 11% ± 1%; P = .024), higher systolic (148 ± 7 vs 135 ± 3 mm Hg; P = .049) and diastolic (91 ± 3 vs 84 ± 2 mm Hg; P = .042) blood pressure, and carotid intima-media thickness (0.92 ± 0.09 vs 0.76 ± 0.02 mm; P = .023). Low concentrations of iMg were related to wave reflection parameters such as increased augmentation pressure (20 ± 2 vs 15 ± 1 mm Hg; P = .032) and augmentation index (43% ± 2% vs 33% ± 2%; P = .004). In conclusion, in these diuretic-treated hypertensive women, low sMg was associated with higher blood pressure values, and more intense wave reflection were closely linked to iMg depletion, processes that might contribute to hypertension and other cardiovascular risk factors.

Characterisation of hypertensive patients with improved endothelial function after dark chocolate consumption.

Recent findings indicate an inverse relationship between cardiovascular disease and consumption of flavonoids. We aimed to identify clinical and vascular parameters of treated hypertensive who present beneficial effects of dark chocolate for one-week period on vascular function. Twenty-one hypertensive subjects, aged 40-65 years, were included in a prospective study with measurement of blood pressure (BP), brachial flow-mediated dilatation (FMD), peripheral arterial tonometry, and central hemodynamic parameters. These tests were repeated after seven days of eating dark chocolate 75 g/day. Patients were divided according to the response in FMD: responders (n = 12) and nonresponders (n = 9). The responder group presented lower age (54 ± 7 versus 61 ± 6 years, P = 0.037), Framingham risk score (FRS) (2.5 ± 1.8 versus 8.1 ± 5.1%, P = 0.017), values of peripheral (55 ± 9 versus 63 ± 5 mmHg, P = 0.041), and central pulse pressure (PP) (44 ± 10 versus 54 ± 6 mmHg, P = 0.021). FMD response showed negative correlation with FRS (r = -0.60, P = 0.014), baseline FMD (r = -0.54, P = 0.011), baseline reactive hyperemia index (RHI; r = -0.56, P = 0.008), and central PP (r = -0.43, P = 0.05). However, after linear regression analysis, only FRS and baseline RHI were associated with FMD response. In conclusion, one-week dark chocolate intake significantly improved endothelial function and reduced BP in younger hypertensive with impaired endothelial function in spite of lower cardiovascular risk.

Vascular dysfunction as target organ damage in animal models of hypertension.

Endothelial dysfunction is one of the main characteristics of chronic hypertension and it is characterized by impaired nitric oxide (NO) bioactivity determined by increased levels of reactive oxygen species. Endothelial function is usually evaluated by measuring the vasodilation induced by the local NO production stimulated by external mechanical or pharmacological agent. These vascular reactivity tests may be carried out in different models of experimental hypertension such as NO-deficient rats, spontaneously hypertensive rats, salt-sensitive rats, and many others. Wire myograph and pressurized myograph are the principal methods used for vascular studies. Usually, increasing concentrations of the vasodilator acetylcholine are added in cumulative manner to perform endothelium-dependent concentration-response curves. Analysis of vascular mechanics is relevant to identify arterial stiffness. Both endothelial dysfunction and vascular stiffness have been shown to be associated with increased cardiovascular risk.

Magnesium and vascular changes in hypertension.

Many factors have been implicated in the pathogenesis of hypertension, including changes in intracellular concentrations of calcium, sodium, potassium, and magnesium. There is a significant inverse correlation between serum magnesium and incidence of cardiovascular diseases. Magnesium is a mineral with important functions in the body such as antiarrhythmic effect, actions in vascular tone, contractility, glucose metabolism, and insulin homeostasis. In addition, lower concentrations of magnesium are associated with oxidative stress, proinflammatory state, endothelial dysfunction, platelet aggregation, insulin resistance, and hyperglycemia. The conflicting results of studies evaluating the effects of magnesium supplements on blood pressure and other cardiovascular outcomes indicate that the action of magnesium in the vascular system is present but not yet established. Therefore, this mineral supplementation is not indicated as part of antihypertensive treatment, and further studies are needed to better clarify the role of magnesium in the prevention and treatment of cardiovascular diseases.

Hipertensão arterial sistêmica / Systemic arterial hipertension

Hipertensão arterial é um problema de saúde pública devido à sua elevada prevalência, falta de controle e associação com eventos cardiovasculares. A avaliação laboratorial visa principalmente a identificação da estimativa de risco cardiovascular, de lesão de órgãos-alvo e de sinais de hipertensão secundária. O objetivo principal do tratamento anti-hipertensivo é a redução da morbidade e mortalidade cardiovascular através da redução da pressão arterial e controle dos fatores de risco associados. Para confirmar o diagnóstico de hipertensão devem ser feitas duas ou mais medidas corretas da pressão arterial. As modificações no estilo de vida devem sempre acompanhar o tratamento anti-hipertensivo. Uma alimentação saudável com base nos princípios do plano alimentar DASH, especialmente quando associada a um consumo restrito de sódio, é capaz de reduzir os níveis da pressão arterial. Além disso, é fundamental moderar o consumo de bebidas alcoólicas e controlar o peso corporal. Até o momento, não parece haver nenhuma clara superioridade de uma classe específica de anti-hipertensivo. A maioria dos pacientes precisará de mais de uma droga para o controle adequado da pressão arterial. A combinação de drogas em doses fixas tem sido reconhecida como uma alternativa para a menor ocorrência de efeitos colaterais e maior aderência ao tratamento, resultando no melhor controle dos níveis pressóricos.

Effects of early postnatal hyperglycaemia on renal cortex maturity, endothelial nitric oxide synthase expression and nephron deficit in mice.

The influence of hyperglycaemia on nephrogenesis on Swiss mice pups treated with streptozotocin (STZ) (40 mg/kg, i.p.) was studied after birth, at 7 and 21 days. Kidneys were prepared for light microscopy, immunohistochemistry and stereology. In 7-day-old pups, both immature and mature glomeruli were evaluated separately. Proliferating cell nuclear antigen (PCNA) and endothelial nitric oxide synthase (eNOS) immunostaining were performed and quantified. At age 7 days, the immature-to-mature glomeruli ratio (IMGR) was significantly higher in the STZ group than in the control group. There was no difference in the number of glomeruli between the STZ and control groups; however, the number of glomeruli increased by more than 20% in the control group until 21 days of age, but not in the STZ group. STZ pups showed numerous PCNA-positive nuclei mainly in tubular cells, but not control pups. At 21 days, eNOS expression in the outer layer of glomerular endothelial nuclei was strong in control pups, but weaker in STZ pups. Treatment with STZ during the early neonatal period disturbs the normal nephrogenesis occurring at this stage of the rodent's life and causes retardation in renal cortical maturity, as indicated by the increase in both PCNA expression and IMGR, and reduction in eNOS expression.

Beneficial effects of physical exercise on hypertension and cardiovascular adverse remodeling of diet-induced obese rats.

BACKGROUND AND AIMS: Obesity is present among all age groups and in all socioeconomic groups. This study on obese rats aims to quantify the beneficial effects of physical exercise on blood pressure (BP), the heart, the elasticity and resistance of arteries. METHODS AND RESULTS: Obese male Wistar rats, (obesity due to a high fat diet with 30% fat), and non-obese rats, were assigned to four groups (n=5): sedentary obese; exercise-practice obese; sedentary control; and exercise-practice control (motor treadmill for 13 weeks). Their organs were studied through light microscopy and stereology. The diet-induced obesity caused mild hypertension with adverse cardiovascular changes. Physical exercise diminished the alterations associated with BP elevation and obesity. The pressure-lowering effect observed in obese rats submitted to physical exercise improved the myocardial vascularization and the aortic and the carotid wall structure by reducing the thickness and normalizing both the elastic lamellae and the smooth muscle cells. The adaptive response of the gluteus superficialis muscle to physical exercise also improved the peripheral resistance arteries of obese rats. CONCLUSION: Current research supports the notion of physical exercise as a potential non-pharmacological antihypertensive treatment for diet-induced obesity hypertension.