Ambulatory blood pressure monitoring. Current status and future perspectives. / Monitorización ambulatoria de la presión arterial. Situación actual y perspectivas futuras.

Ambulatory Blood Pressure Monitoring (ABPM) is considered the best method for obtaining a reliable estimation of the true blood pressure. Average values obtained during the whole 24-hour period, or during daytime and nighttime periods are better correlated with the risk of mortality and cardiovascular disease compared to clinic or office blood pressure. Indeed, nighttime blood pressure, a measure only obtained through ABPM, is the most powerful risk predictor. ABPM is complementary to clinic blood pressure measurement and allows the definition of blood pressure phenotypes, such as "white-coat or masked hypertension, when clinic and ABPM measurements show discrepancy in normal values. Additional potentially relevant features include blood pressure variability, such as nocturnal blood pressure decline, morning surge or short-term variability, as determined by standard deviation or the coefficient of variation.

Variablilidad de la presión arterial, hipertensión arterial nocturna y su asociación con tabaquismo / Blood pressure variability, nocturnal hypertension and its association with smoking / Variabilidade da pressão arterial, hipertensão arterial noturna e sua associação com o tabagismo

Resumen: Introducción: La hipertensión arterial y el tabaquismo son factores de riesgo independientes para el desarrollo de eventos cardiovasculares. El consumo de tabaco determina una elevación aguda de la presión arterial por acción del sistema simpático. Sin embargo los efectos a largo plazo son contradictorios. El aumento de la variabilidad de la presión arterial y la presencia de hipertensión arterial nocturna se asocia con eventos cardiovasculares adversos independientemente de los niveles de presión arterial. Objetivos: Evaluar la asociación entre tabaquismo e hipertensión arterial diurna, nocturna y variabilidad. Material y Métodos: Estudio analítico, observacional, transversal, multicéntrico, que incluye pacientes hipertensos mayores de 18 años con monitoreo ambulatorio de la presión arterial (MAPA). Resultados: Se incluyeron 391 pacientes, siendo 14.6% fumadores. Se encontraron cifras de presión arterial diurna sistólica y diastólica más elevadas en pacientes tabaquistas (p=0.204, p=0.087, respectivamente). Se observó una asociación significativa entre la hipertensión arterial nocturna y la presencia de diabetes mellitus e índice de masa corporal aumentado. No se encontró asociación entre el consumo de tabaco y los distintos patrones de variabilidad, así como tampoco con la hipertensión arterial nocturna. Conclusiones: El grupo de pacientes fumadores presentó una tendencia a cifras de presión arterial media diurna sistólica y diastólica más elevadas que los no fumadores, lo que podría sugerir que el tabaquismo incide en el control de cifras de presión arterial.

Abstract: Introduction: Hypertension and smoking are independent risk factors for the development of cardiovascular events. Tobacco use causes an acute elevation of blood pressure due to the action of the sympathetic system. However, the long-term effects are contradictory. Increased variability in blood pressure and the presence of nocturnal arterial hypertension are associated with adverse cardiovascular events regardless of blood pressure levels. Objectives: To evaluate the association between smoking and daytime and nighttime arterial hypertension and variability. Material and Methods: Analytical, observational, cross-sectional, multicenter study, which includes hypertensive patients over 18 years of age with ambulatory blood pressure monitoring (ABPM). Results: 391 patients were included, being 14.6% smokers. Higher levels of systolic and diastolic daytime blood pressure were found in smoking patients (p = 0.204, p = 0.087, respectively). A significant association was observed between nocturnal arterial hypertension and the presence of diabetes mellitus and increased body mass index. No association was found between tobacco consumption and the different patterns of variability, as well as with nocturnal arterial hypertension. Conclusions: The group of smoking patients showed a trend towards higher mean daytime systolic and diastolic blood pressure figures than non-smokers, which could suggest that smoking affects the control of blood pressure numbers.

Resumo: Introdução: Hipertensão e tabagismo são fatores de risco independentes para o desenvolvimento de eventos cardiovasculares. O uso do tabaco provoca elevação aguda da pressão arterial devido à ação do sistema simpático. No entanto, os efeitos de longo prazo são contraditórios. O aumento da variabilidade da pressão arterial e a presença de hipertensão arterial noturna estão associados a eventos cardiovasculares adversos, independentemente dos níveis de pressão arterial. Objetivos: Avaliar a associação entre tabagismo e hipertensão arterial diurna e noturna e variabilidade. Materiai e Métodos: Estudo analítico, observacional, transversal, multicêntrico, que inclui hipertensos maiores de 18 anos com monitorização ambulatorial da pressão arterial (MAPA). Resultados: Foram incluídos 391 pacientes, sendo 14,6% tabagistas. Níveis mais elevados de pressão arterial diurna sistólica e diastólica foram encontrados em pacientes fumantes (p = 0,204, p = 0,087, respectivamente). Foi observada associação significativa entre hipertensão arterial noturna e presença de diabetes mellitus e aumento do índice de massa corporal. Não foi encontrada associação entre o consumo de tabaco e os diferentes padrões de variabilidade, bem como com a hipertensão arterial noturna. Conclusões: O grupo de pacientes fumantes apresentou tendência a valores médios de pressão arterial sistólica e diastólica mais elevados do que os não fumantes, o que pode sugerir que o tabagismo afeta o controle dos valores da pressão arterial.

[Ambulatory blood pressure monitoring is a useful tool for all patients]. / La monitorización ambulatoria de la presión arterial es un instrumento aconsejable para todos los pacientes.

Clinical blood pressure measurement (BP) is an occasional and imperfect way of estimating this biological variable. Ambulatory blood pressure monitoring (ABPM) is by far the best clinical tool for measuring an individual's blood pressure. Mean values over 24h, through the daytime and at night all make it more possible to predict organic damage and the future development of the disorder. ABPM enables the detection of white-coat hypertension and masked hypertension in both the diagnosis and follow-up of treated patients. Although some of the advantages of ABPM can be reproduced by more automated measurement without the presence of an observer in the clinic or self-measurement at home, there are some other elements of great interest that are unique to ABPM, such as seeing what happens to a patient's BP at night, the night time dipping pattern and short-term variability, all of which relate equally to the patient's prognosis. There is no scientific or clinical justification for denying these advantages, and ABPM should form part of the evaluation and follow-up of practically all hypertensive patients. Rather than continuing unhelpful discussions as to its availability and acceptability, we should concentrate our efforts on ensuring its universal availability and clearly explaining its advantages to both doctors and patients.

The relationship between dietary salt intake and ambulatory blood pressure variability in non-diabetic hypertensive patients.

High dietary salt intake was reported to increase blood pressure by numerous studies, but no study has investigated the effect of dietary salt intake on blood pressure variability (BPV). This study aimed to determine if daily salt intake is related to ambulatory BPV. The study included 136 primary hypertensive patients (92 male, 44 female) with a mean age of 50.7±11.1 years. All the patients underwent 24-h ambulatory blood pressure monitoring to determine both the 24-h systolic and 24-h diastolic BPV. 24-h urine sodium was measured. The correlation between BPV and 24-h urinary sodium was investigated. Logarithmic transformation of 24-h urinary sodium [log(24-h urinary sodium)] was positively correlated with the mean 24-h systolic ARV, and nighttime systolic ARV (r=0.371 and p=0.001, r=0.329 and p=0.028, respectively). Similarly, log(24-h urinary sodium) was positively correlated with mean 24-h diastolic ARV and nighttime diastolic ARV (r=0.381 and p=0.001, r=0.320 and p=0.020 respectively). Log(24-h urinary sodium) was an independent predictor of BPV based on multivariate regression analysis. Dietary salt intake might play a role in the pathogenesis of ambulatory BPV.

Effects of Chronic Carvedilol administration on blood Pressure Variability and target Organ injury in rats with sinoaortic Denervation / Efectos de la administración crónica de carvedilol sobre la variabilidad de la presión arterial y el daño de órgano blanco en ratas con desnervación sinoaórtica

background: Increased blood pressure variability is a novel risk factor for the development of target organ injury both in hyperten-sive and normotensive subjects, so its reduction should be considered as a new therapeutic goal. Objective: The aim of this study was to evaluate the effect of long-term oral carvedilol treatment on blood pressure, blood pressure variability and target organ injury in the left ventricle and thoracic aorta in a model of blood pressure liability. Methods: Twelve male Wistar rats submitted to sinoaortic denervation were treated during 8 weeks with a single dose of carvedilol 30 mg/kg or vehicle. At the end of treatment, echocardiographic evaluation and blood pressure and short-term variability measure-ments were performed. Left ventricular and thoracic aortic weights were determined and histological samples were prepared from both tissues. Metalloproteinase MMP-2 and transforming growth factor β (TGF-β) were quantified in the left ventricle and thoracic aorta. results: Carvedilol reduced systolic blood pressure and its variability in sinoaortic-denervated rats compared with the control group (126±5 vs. 142±11 mmHg, p<0.05; SD: 2.9±0.5 vs. 6.0±0.5 mmHg; p<0.05). A lower amount of connective tissue was found in carvedilol-treated animals. The expression of TGF-β decreased in both organs after carvedilol treatment. Conclusions: Chronic carvedilol treatment significantly reduces systolic blood pressure and its short-term variability in sinoaortic-denervated rats, decreasing the degree of left ventricular fibrosis.

introducción: El incremento en la variabilidad de la presión arterial resulta un nuevo factor de riesgo para el desarrollo de daño de órgano blanco en individuos tanto hipertensos como normotensos, por lo que se postula que su reducción debe considerarse una posible nueva meta terapéutica. Objetivos: Evaluar el efecto del tratamiento a largo plazo con carvedilol sobre la presión arterial, su variabilidad y el daño de órgano blanco en el ventrículo izquierdo y la aorta torácica en el modelo de la labilidad de presión. Material y métodos: Se incluyeron 12 ratas Wistar macho sometidas a desnervación sinoaórtica, las cuales fueron tratadas durante 8 semanas con una única administración diaria de carvedilol 30 mg/kg o vehículo. Finalizado el tratamiento se realizó la medición de la presión arterial y de la variabilidad a corto plazo y la evaluación ecocardiográfica. Se determinó el peso del ventrículo y de la aorta torácica y se realizaron preparados histológicos sobre ambos tejidos. Se cuantificó la expresión de metaloproteinasa 2 (MMP-2) y factor de crecimiento transformante β (TGF-β) en el ventrículo izquierdo y la aorta torácica. resultados: El carvedilol redujo la presión arterial sistólica y su variabilidad en las ratas con desnervación sinoaórtica en comparación con el grupo control (126 ± 5 vs. 142 ± 11 mm Hg, p < 0,05; DE: 2,9 ± 0,5 vs. 6,0 ± 0,5 mm Hg; p < 0,05). Se evidenció menor cantidad de tejido conectivo en los animales tratados con carvedilol. La expresión de TGF-β se encuentra disminuida en ambos órganos luego del tratamiento con carvedilol. Conclusiones: El tratamiento crónico con carvedilol reduce significativamente la presión arterial y su variabilidad a corto plazo en ratas con desnervación sinoaórtica, disminuyendo el grado de fibrosis del ventrículo izquierdo.

Perfil farmacocinético y farmacodinámico del nebivolol en un modelo experimental de síndrome metabólico / Pharmacokinetic and Pharmacodynamic Profile of Nebivolol in an Animal Model of Metabolic Syndrome

Con el objetivo en este estudio de evaluar los efectos cardiovasculares y la farmacocinética del nebivolol en ratas hipertensas por sobrecarga de fructosa y en ratas control, se registraron los efectos de la administración intravenosa de nebivolol, 3 mg/kg o 10 mg/kg, sobre la presión arterial, la frecuencia cardíaca y la variabilidad de la presión arterial a corto plazo y latido-a-latido, y se evaluó la farmacocinética enantioselectiva a partir del análisis de la concentración plasmática de los enantiómeros d-nebivolol y l-nebivolol. La variabilidad de la presión arterial a corto plazo y latido-a-latido se evaluó mediante la desviación estándar y el análisis espectral del registro de la presión arterial, respectivamente. El estado hipertensivo alteró la farmacocinética del nebivolol, evidenciado por una reducción en el aclaramiento del nebivolol en el grupo fructosa respecto del grupo control luego de la administración de la dosis más alta. El efecto antihipertensivo del nebivolol fue similar en ambos grupos, en tanto que el efecto bradicardizante fue mayor en las ratas del grupo control. Aunque no se observaron diferencias significativas en la variabilidad de la presión arterial latido-a-latido, la reducción de la variabilidad de la presión arterial a corto plazo inducida por el nebivolol fue significativamente superior en las ratas del grupo fructosa en comparación con los animales normotensos (-57,9% ± 11,8% vs. -19,6% ± 9,2%; p < 0,05). En conclusión, si bien el nebivolol reduce la presión arterial y la variabilidad de la presión arterial en ambos grupos, no se encontraron diferencias significativas en las ratas con sobrecarga de fructosa en cuanto a la farmacocinética y los efectos cardiovasculares, a excepción de una eficacia bradicardizante menor y una reducción mayor de la variabilidad de la presión arterial a corto plazo.

The cardiovascular and pharmacokinetic effects of nebivolol were evaluated in hypertensive fructose-fed and control rats, analyzing the effect of intravenously administered nebivolol 3 or 10 mg/kg on blood pressure, heart rate, and short-term and beat-to-beat blood pressure variability. The enantioselective pharmacokinetic profile of d- and l-nebivolol enantiomers was evaluated. Short-term and beat-to-beat blood pressure variability was assessed using standard deviation and blood pressure spectral analysis, respectively. The hypertensive state altered the pharmacokinetics of nebivolol, evidenced by reduction of nebivolol clearance in the fructose group compared to the control group after administration of the highest dose. The antihypertensive effect of nebivolol was similar in both groups, while the bradycardic effect was greater in control rats. Although no significant differences were found in beat-to-beat blood pressure variability, short-term blood pressure variability showed greater reduction after nebivolol administration in fructose-fed rats compared to control normotensive animals (-57.9%±11.8% vs.-19.6%±9.2%; p<0.05). In conclusion, although nebivolol reduces blood pressure and blood pressure variability in both groups, no significant differences were found in the pharmacokinetics and cardiovascular effects of fructose-fed rats, except for lower bradycardic efficacy and greater reduction in short-term blood pressure variability.