RESUMO
BACKGROUND: The use of automated (oscillometric) blood pressure (BP) devices is not validated in atrial fibrillation (AF) patients. OBJECTIVES: To assess the reliability of three oscillometric BP devices, and the agreement with invasive arterial blood pressure(IBP) in AF patients. METHODS: 48 AF patients with randomized sequences of 10 consecutive BP measurements with two pairs of devices: (1) OmronR7™(wrist) and OmronHEM907™(arm); (2) OmronR7™ and Microlife WatchBPhome(arm). Reliability and agreement of each device were assessed by the intra-class correlation coefficient (ICC) for the continuous BP measurements and Bland & Altman methodology, respectively. In 10 additional AF patients, 10 consecutive measurements with IBP and OmronHEM907™, and IBP and Microlife WatchBPhome were performed. RESULTS: The OmronR7™ was not able to obtain any BP Readings. Arm devices presented better ICC for systolicBP(SBP) than for diastolicBP(DBP) (Omron HEM907™:0.94 [0.90; 0.97] vs. 0.77 [0.67; 0.89]; Microlife WatchBPhome:0.92 [0.88; 0.96] vs.0.79 [0.69; 0.89]).The correlation coefficient between Microlife WatchBPhome and IBP computed using the average of repeated measurements from two to ten measurements improved up to the third and remained stable afterwards. The agreement between IBP and SBP, and IBP and DBP, was moderate as illustrated by a wide limit of agreement [-24; 26](SBP) and [-15;17](DBP) for Microlife WatchBPHome, respectively and [-30; 13](SBP) and [-7; 15](DBP) for OmronHEM907. CONCLUSIONS: BP measurement using the two arm oscillometric devices achieved a high reliability for SBP. The agreement between IBP and arm devices was low but using the average of three consecutive measurements improved the results substantially.
Assuntos
Fibrilação Atrial/diagnóstico , Determinação da Pressão Arterial/métodos , Pressão Sanguínea/fisiologia , Idoso , Idoso de 80 Anos ou mais , Fibrilação Atrial/patologia , Feminino , Humanos , MasculinoRESUMO
Myocardial infarction (MI) induces a sterile inflammatory response that contributes to adverse cardiac remodeling. The initiating mechanisms of this response remain incompletely defined. We found that necrotic cardiomyocytes released a heat-labile proinflammatory signal activating MAPKs and NF-κB in cardiac fibroblasts, with secondary production of cytokines. This response was abolished in Myd88(-/-) fibroblasts but was unaffected in nlrp3-deficient fibroblasts. Despite MyD88 dependency, the response was TLR independent, as explored in TLR reporter cells, pointing to a contribution of the IL-1 pathway. Indeed, necrotic cardiomyocytes released IL-1α, but not IL-1ß, and the immune activation of cardiac fibroblasts was abrogated by an IL-1R antagonist and an IL-1α-blocking Ab. Moreover, immune responses triggered by necrotic Il1a(-/-) cardiomyocytes were markedly reduced. In vivo, mice exposed to MI released IL-1α in the plasma, and postischemic inflammation was attenuated in Il1a(-/-) mice. Thus, our findings identify IL-1α as a crucial early danger signal triggering post-MI inflammation.
Assuntos
Interleucina-1alfa/imunologia , Infarto do Miocárdio/imunologia , Miocardite/imunologia , Miócitos Cardíacos/imunologia , Transdução de Sinais/imunologia , Animais , Inflamação/etiologia , Inflamação/genética , Inflamação/imunologia , Inflamação/patologia , Interleucina-1alfa/genética , Interleucina-1beta/genética , Interleucina-1beta/imunologia , Camundongos , Camundongos Knockout , Fator 88 de Diferenciação Mieloide/genética , Fator 88 de Diferenciação Mieloide/imunologia , Infarto do Miocárdio/complicações , Infarto do Miocárdio/genética , Infarto do Miocárdio/patologia , Miocardite/etiologia , Miocardite/genética , Miocardite/patologia , Miócitos Cardíacos/patologia , Transdução de Sinais/genética , Receptores Toll-Like/genética , Receptores Toll-Like/imunologiaRESUMO
PURPOSE: Thoracic fat has been associated with an increased risk of coronary artery disease (CAD). As endothelium-dependent vasoreactivity is a surrogate of cardiovascular events and is impaired early in atherosclerosis, we aimed at assessing the possible relationship between thoracic fat volume (TFV) and endothelium-dependent coronary vasomotion. METHODS: Fifty healthy volunteers without known CAD or major cardiovascular risk factors (CRFs) prospectively underwent a (82)Rb cardiac PET/CT to quantify myocardial blood flow (MBF) at rest, and MBF response to cold pressor testing (CPT-MBF) and adenosine (i.e., stress-MBF). TFV was measured by a 2D volumetric CT method and common laboratory blood tests (glucose and insulin levels, HOMA-IR, cholesterol, triglyceride, hsCRP) were performed. Relationships between CPT-MBF, TFV and other CRFs were assessed using non-parametric Spearman rank correlation testing and multivariate linear regression analysis. RESULTS: All of the 50 participants (58 ± 10y) had normal stress-MBF (2.7 ± 0.6 mL/min/g; 95 % CI: 2.6-2.9) and myocardial flow reserve (2.8 ± 0.8; 95 % CI: 2.6-3.0) excluding underlying CAD. Univariate analysis revealed a significant inverse relation between absolute CPT-MBF and sex (ρ = -0.47, p = 0.0006), triglyceride (ρ = -0.32, p = 0.024) and insulin levels (ρ = -0.43, p = 0.0024), HOMA-IR (ρ = -0.39, p = 0.007), BMI (ρ = -0.51, p = 0.0002) and TFV (ρ = -0.52, p = 0.0001). MBF response to adenosine was also correlated with TFV (ρ = -0.32, p = 0.026). On multivariate analysis, TFV emerged as the only significant predictor of MBF response to CPT (p = 0.014). CONCLUSIONS: TFV is significantly correlated with endothelium-dependent and -independent coronary vasomotion. High TF burden might negatively influence MBF response to CPT and to adenosine stress, even in persons without CAD, suggesting a link between thoracic fat and future cardiovascular events.
Assuntos
Tecido Adiposo Branco/diagnóstico por imagem , Doença da Artéria Coronariana/epidemiologia , Circulação Coronária , Vasos Coronários/diagnóstico por imagem , Tórax/diagnóstico por imagem , Idoso , Endotélio Vascular/diagnóstico por imagem , Feminino , Voluntários Saudáveis , Hemodinâmica , Humanos , Masculino , Pessoa de Meia-Idade , Imagem Multimodal , Tomografia por Emissão de Pósitrons , Compostos Radiofarmacêuticos , Fatores de Risco , Radioisótopos de Rubídio , Tomografia Computadorizada por Raios XRESUMO
Brain natriuretic peptide (BNP) contributes to heart formation during embryogenesis. After birth, despite a high number of studies aimed at understanding by which mechanism(s) BNP reduces myocardial ischemic injury in animal models, the actual role of this peptide in the heart remains elusive. In this study, we asked whether BNP treatment could modulate the proliferation of endogenous cardiac progenitor cells (CPCs) and/or their differentiation into cardiomyocytes. CPCs expressed the NPR-A and NPR-B receptors in neonatal and adult hearts, suggesting their ability to respond to BNP stimulation. BNP injection into neonatal and adult unmanipulated mice increased the number of newly formed cardiomyocytes (neonatal: +23 %, p = 0.009 and adult: +68 %, p = 0.0005) and the number of proliferating CPCs (neonatal: +142 %, p = 0.002 and adult: +134 %, p = 0.04). In vitro, BNP stimulated CPC proliferation via NPR-A and CPC differentiation into cardiomyocytes via NPR-B. Finally, as BNP might be used as a therapeutic agent, we injected BNP into mice undergoing myocardial infarction. In pathological conditions, BNP treatment was cardioprotective by increasing heart contractility and reducing cardiac remodelling. At the cellular level, BNP stimulates CPC proliferation in the non-infarcted area of the infarcted hearts. In the infarcted area, BNP modulates the fate of the endogenous CPCs but also of the infiltrating CD45(+) cells. These results support for the first time a key role for BNP in controlling the progenitor cell proliferation and differentiation after birth. The administration of BNP might, therefore, be a useful component of therapeutic approaches aimed at inducing heart regeneration.
Assuntos
Coração/efeitos dos fármacos , Miocárdio/citologia , Peptídeo Natriurético Encefálico/farmacologia , Células-Tronco/efeitos dos fármacos , Animais , Animais Recém-Nascidos , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Proteína Homeobox Nkx-2.5 , Proteínas de Homeodomínio/análise , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Infarto do Miocárdio/tratamento farmacológico , Miócitos Cardíacos/fisiologia , Receptores do Fator Natriurético Atrial/fisiologia , Células-Tronco/citologia , Células-Tronco/fisiologia , Fatores de Transcrição/análiseRESUMO
PURPOSE OF REVIEW: There is currently much interest in the usefulness of out-of-office blood pressure (BP) for the diagnosis and the management of hypertension in patients with chronic kidney disease (CKD). This is not to suggest that office BP should be disregarded and we will take the opportunity to stress how it could be improved. RECENT FINDINGS: Arterial hypertension constitutes a very relevant cardiovascular and renal risk factor in patients with CKD. To assess this risk, the best tool is ambulatory BP monitoring (ABPM), as it allows the detection of masked hypertension, masked untreated hypertension (MUCH) and nondipping pattern, conditions known to be associated with target organ damage that further contributes to increased risk to the patient. Home BP monitoring (HBPM) cannot fully substitute for ABPM because of the absence of BP data during the night. Despite this, there are good reasons to use HBPM systematically in patients with CKD during long-term follow-up. SUMMARY: In the individual patient office, BP may significantly differ from out-of-office measurements. This shortcoming can be attenuated by repeated measurement at every visit, but even if office BP is considered normal, it is still highly desirable to obtain out-of-office data.
Assuntos
Determinação da Pressão Arterial , Monitorização Ambulatorial da Pressão Arterial , Pressão Sanguínea/fisiologia , Hipertensão/diagnóstico , Insuficiência Renal Crônica/diagnóstico , Animais , Determinação da Pressão Arterial/métodos , Análise Custo-Benefício , Humanos , Hipertensão/fisiopatologia , Insuficiência Renal Crônica/fisiopatologiaRESUMO
Myocardial ischaemia-reperfusion (MIR) triggers a sterile inflammatory response important for myocardial healing, but which may also contribute to adverse ventricular remodelling. Such inflammation is initiated by molecular danger signals released by damaged myocardium, which induce innate immune responses by activating toll-like receptors (TLRs). Detrimental roles have been recently reported for TLR2, TLR3 and TLR4. The role of other TLRs is unknown. We therefore evaluated the role of TLR5, expressed at high level in the heart, in the development of myocardial damage and inflammation acutely triggered by MIR. TLR5(-/-) and wild-type (WT) mice were exposed to MIR (30 min ischaemia, 2 h reperfusion). We measured infarct size, markers of cardiac oxidative stress, myocardial phosphorylation state of mitogen-activated protein (MAP) kinases and AKT, expression levels of chemokines and cytokines in the heart and plasma, as well as cardiac function by echography and conductance volumetry. TLR5-deficient mice had normal cardiac morphology and function under physiological conditions. After MIR, the absence of TLR5 promoted an increase in infarct size and myocardial oxidative stress. Lack of TLR5 fostered p38 phosphorylation, reduced AKT phosphorylation and markedly increased the expression of inflammatory cytokines, whereas it precipitated acute LV (left ventricle) dysfunction. Therefore, contrary to the detrimental roles of TLR2, TLR3 and TLR4 in the infarcted heart, TLR5 is important to limit myocardial damage, inflammation and functional compromise after MIR.
Assuntos
Mediadores da Inflamação/metabolismo , Inflamação/metabolismo , Infarto do Miocárdio/metabolismo , Traumatismo por Reperfusão Miocárdica/metabolismo , Miocárdio/metabolismo , Receptor 5 Toll-Like/deficiência , Animais , Modelos Animais de Doenças , Genótipo , Imunidade Inata , Inflamação/genética , Inflamação/imunologia , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Infarto do Miocárdio/genética , Infarto do Miocárdio/imunologia , Infarto do Miocárdio/patologia , Infarto do Miocárdio/fisiopatologia , Traumatismo por Reperfusão Miocárdica/genética , Traumatismo por Reperfusão Miocárdica/imunologia , Traumatismo por Reperfusão Miocárdica/patologia , Traumatismo por Reperfusão Miocárdica/fisiopatologia , Miocárdio/imunologia , Miocárdio/patologia , Estresse Oxidativo , Fenótipo , Fosforilação , Proteínas Proto-Oncogênicas c-akt/metabolismo , Receptor 5 Toll-Like/genética , Disfunção Ventricular Esquerda/imunologia , Disfunção Ventricular Esquerda/metabolismo , Disfunção Ventricular Esquerda/patologia , Disfunção Ventricular Esquerda/fisiopatologia , Função Ventricular Esquerda , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismoRESUMO
AIMS: We investigated the potential influence of a moderate-to-high cardiovascular (CV) risk (CVR) (defined as a Systematic COronary Risk Evaluation model, or SCORE ≥ 4%), in the absence of an established CV disease, on the duration and cost of CV and non-CV sick leave (SL) resulting from common and occupational accidents or diseases. METHODS AND RESULTS: We conducted a prospective cohort study on 690 135 workers with a 1-year follow-up and examined CV- and non-CV-related SL episodes. To obtain baseline values, CVR factors were initially assessed at the beginning of the year during routine medical examination. The CVR was calculated with the SCORE charts for all subjects. Moderate-to-high CVR was defined as SCORE ≥ 4%. A baseline SCORE ≥ 4% was associated with a higher risk for long-term CV and non-CV SL, as revealed by follow-up assessment. This translated into an increased cost, estimated at 5 801 464.18 per year. Furthermore, pharmacological treatment for hypertension or hyperlipidaemia was significantly associated with longer SL duration. CONCLUSION: Moderate-to-high CVR in asymptomatic subjects was significantly associated with the duration and cost of CV and non-CV SL. These results constitute the first body of evidence that the SCORE charts can be used to identify people with a non-established CV disease, which might ultimately translate into more lost workdays and therefore increased cost for society.
Assuntos
Doenças Cardiovasculares/economia , Licença Médica/economia , Acidentes de Trabalho/economia , Acidentes de Trabalho/estatística & dados numéricos , Adolescente , Adulto , Distribuição por Idade , Idoso , Custos e Análise de Custo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Risco , Distribuição por Sexo , Espanha , Fatores de Tempo , Adulto JovemRESUMO
OBJECTIVE: This study was undertaken to investigate how aging affects dermal microvascular reactivity in skin areas differentially exposed to sunlight, and therefore to different degrees of photoaging. METHODS: We assessed, in young (18-30 years, n = 13) and aged males (≥60 years, n = 13), the thigh, forearm, and forehead's skin vasodilatory response to local heating (LTH) with a LDI. In each subject and at each location, local Tskin was brought from 34°C (baseline) to 39 or 41°C for 30 minutes, to effect submaximal vasodilation, with maximal vasodilation then elicited by further heating to 44°C. RESULTS: The CVCs evaluated at baseline and after maximal vasodilation (CVCmax ) were higher in the forehead than in the two other anatomical locations. On all locations, CVCmax decreased with age but less markedly in the forehead compared to the two other locations. When expressed in % of CVCmax , the plateau increase of CVCs in response to submaximal temperatures (39 and 41°C) did not vary with age, and minimally so with location. CONCLUSION: Skin aging, whether intrinsic or combined with photoaging, reduces the maximal vasodilatory capacity of the dermal microcirculation, but not its reactivity to local heating.
Assuntos
Temperatura Alta , Envelhecimento da Pele , Pele , Vasodilatação , Adolescente , Adulto , Velocidade do Fluxo Sanguíneo , Humanos , Masculino , Pele/irrigação sanguínea , Pele/patologia , Pele/fisiopatologiaRESUMO
Hypertension resistant to lifestyle interventions and antihypertensive medications is a common problem encountered by physicians in everyday practice. It is most often defined as a blood pressure remaining ≥ 140/90 mmHg despite the regular intake of at least three drugs lowering blood pressure by different mechanisms, one of them being a diuretic. It now appears justified to include, unless contraindicated or not tolerated, a blocker of the renin-angiotensin system and a calcium channel blocker in this drug regimen, not only to gain antihypertensive efficacy, but also to prevent or regress target organ damage and delay the development of cardiorenal complications. A non-negligible fraction of treatment-resistant hypertension have normal "out of office" blood pressures. Ambulatory blood pressure monitoring and/or home blood pressure recording should therefore be routinely performed to identify patients with true resistant hypertension, i.e. patients who are more likely to benefit from treatment intensification.
Assuntos
Hipertensão/diagnóstico , Hipertensão/tratamento farmacológico , Anti-Hipertensivos/uso terapêutico , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
According to recent international guidelines, 24-h ambulatory blood pressure monitoring plays an important role in the diagnostic and therapeutic approach of arterial hypertension. Indications of this technique are multiple, concerning both day- and night-time blood pressures. Blood pressures provided by ambulatory monitoring may be used to stratify cardiovascular risk.
Assuntos
Monitorização Ambulatorial da Pressão Arterial , Hipertensão/diagnóstico , Hipertensão/terapia , Pressão Sanguínea/fisiologia , Monitorização Ambulatorial da Pressão Arterial/normas , Monitorização Ambulatorial da Pressão Arterial/estatística & dados numéricos , Diagnóstico Diferencial , Humanos , Hipertensão Mascarada/diagnóstico , Valores de Referência , Hipertensão do Jaleco Branco/diagnósticoRESUMO
There is evidence that reactive hyperemia (ie, the transient increase of blood flow above resting level after a short period of ischemia) could be negatively modulated by vasoconstrictor prostanoids. The present study tested whether pharmacological blockade of the thromboxane prostanoid receptors with the specific antagonist S18886 (terutroban) would amplify reactive hyperemia in human skin and skeletal muscle. Twenty healthy young male volunteers were enrolled in a randomized, blinded, crossover trial of oral S18886 30 mg/d for 5 days versus placebo. Reactive hyperemia was evaluated in forearm skin and skeletal muscle, after occlusion of the brachial artery with a pneumatic cuff inflated at suprasystolic pressure. Blood flow was measured with laser Doppler imaging (skin) and strain gauge venous occlusion plethysmography (muscle). On the first and last day of each treatment period, recordings of reactive hyperemia were obtained immediately before and 2 hours after drug intake. Whether in forearm muscle or skin, S18886 had no discernible effect on peak postocclusion blood flow, nor on the global hyperemic response as quantified by the area under curve. These results do not support that thromboxane prostanoid receptor activation could exert a moderating influence on reactive hyperemia in human skin and skeletal muscle, at least in young subjects.
Assuntos
Hiperemia/etiologia , Músculo Esquelético/efeitos dos fármacos , Naftalenos/farmacologia , Propionatos/farmacologia , Receptores de Tromboxano A2 e Prostaglandina H2/metabolismo , Pele/efeitos dos fármacos , Adolescente , Adulto , Estudos Cross-Over , Método Duplo-Cego , Antebraço/irrigação sanguínea , Humanos , Fluxometria por Laser-Doppler , Masculino , Músculo Esquelético/irrigação sanguínea , Pletismografia , Receptores de Tromboxano A2 e Prostaglandina H2/antagonistas & inibidores , Pele/irrigação sanguínea , Adulto JovemRESUMO
Orthostatic hypotension is encountered frequently in everyday practice. It is often very disabling because of its troublesome symptomalogy. Orthostatic hypotension may be due to several causes and can be easily diagnosed by measuring blood pressure and heart rate after 3 minutes in upright posture. Its treatment comprises in all cases non-pharmacological interventions which can be associated whenever required by medications, in particular midodrine and fludrocortisone.
Assuntos
Fludrocortisona/uso terapêutico , Hipotensão Ortostática/terapia , Midodrina/uso terapêutico , Pressão Sanguínea , Frequência Cardíaca , Humanos , Hipotensão Ortostática/etiologia , Hipotensão Ortostática/fisiopatologia , Vasoconstritores/uso terapêuticoRESUMO
The last recommendations of the European Society of Hypertension and the European Society of Cardiology made available deal with the diagnosis and the treatment of arterial hypertension. They point to the importance of both 24-hour ambulatory blood pressure monitoring and home blood pressure measurement. They also underscore the importance of stratifying cardiovascular risk and of controlling strictly blood pressure using hygienic measures and antihypertensive drugs, either as monotherapy or combination therapy.
Assuntos
Anti-Hipertensivos/uso terapêutico , Monitorização Ambulatorial da Pressão Arterial/métodos , Hipertensão/terapia , Anti-Hipertensivos/administração & dosagem , Pressão Sanguínea , Quimioterapia Combinada , Europa (Continente) , Humanos , Hipertensão/diagnóstico , Hipertensão/fisiopatologia , Estilo de Vida , Fatores de Risco , Sociedades MédicasRESUMO
OBJECTIVES: Capillary rarefaction is a hallmark of untreated hypertension. Recent data indicate that rarefaction may be reversed by antihypertensive treatment in nondiabetic hypertensive patients. Despite the frequent association of diabetes with hypertension, nothing is known on the capillary density of treated diabetic patients with hypertension. METHODS: We enrolled 21 normotensive healthy, 25 hypertensive only, and 21 diabetic (type 2) hypertensive subjects. All hypertensive patients were treated with a blocker of the renin-angiotensin system, and a majority had a home blood pressure ≤135/85 mmHg. Capillary density was assessed with videomicroscopy on dorsal finger skin and with laser Doppler imaging on forearm skin (maximal vasodilation elicited by local heating). RESULTS: There was no difference between any of the study groups in either dorsal finger skin capillary density (controls 101 ± 11 capillaries/mm(2) , nondiabetic hypertensive 99 ± 16, diabetic hypertensive 96 ± 18, p > 0.5) or maximal blood flow in forearm skin (controls 666 ± 114 perfusion units, nondiabetic hypertensive 612 ± 126, diabetic hypertensive 620 ± 103, p > 0.5). CONCLUSIONS: Irrespective of the presence or not of type 2 diabetes, capillary density is normal in hypertensive patients with reasonable control of blood pressure achieved with a blocker of the renin-angiotensin system.
Assuntos
Capilares/fisiopatologia , Diabetes Mellitus Tipo 2/fisiopatologia , Hipertensão/fisiopatologia , Pele/irrigação sanguínea , Pele/fisiopatologia , Adulto , Idoso , Capilares/patologia , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/patologia , Feminino , Dedos/irrigação sanguínea , Dedos/patologia , Dedos/fisiopatologia , Humanos , Hipertensão/complicações , Hipertensão/tratamento farmacológico , Hipertensão/patologia , Fluxometria por Laser-Doppler , Masculino , Microscopia de Vídeo , Pessoa de Meia-Idade , Sistema Renina-Angiotensina/efeitos dos fármacos , Pele/patologiaRESUMO
OBJECTIVE: Local heating increases skin blood flow SkBF (thermal hyperemia). In a previous study, we reported that a first local thermal stimulus could attenuate the hyperemic response to a second one applied later on the same skin spot, a phenomenon that we termed desensitization. However, other studies found no evidence for desensitization in similar conditions. The aim of the present work was to test whether it was related to differences in instrumentation. METHODS: Twenty-eight healthy young males were studied. Two pairs of heating chambers, one custom-made (our study) and one commercial (other groups), were affixed to forearm skin. SkBF was measured with single-point laser-Doppler flowmetry (LDF) (780nm) in one pair, and laser-Doppler imaging (LDI) (633nm) in the other. A temperature step from 34 to 41°C, was applied for 30minutes and repeated after two hours. RESULTS: During the second thermal challenge, the plateau SkBF was lower than during the first thermal and was observed with each of the four combinations of SkBF measurement techniques and heating equipment (p<0.05 for all conditions, range -9% to -16% of the initial value). CONCLUSION: Desensitization of thermal hyperemia is not specific to peculiar operating conditions.
Assuntos
Temperatura Alta , Hiperemia/fisiopatologia , Fluxometria por Laser-Doppler/métodos , Pele/irrigação sanguínea , Adolescente , Adulto , Humanos , Masculino , Reprodutibilidade dos Testes , Fatores de TempoRESUMO
The prevalence of both hypertension and vitamin D deficiency is high. The discovery of the vitamin D receptor and its possible effects on components of the cardiovascular system influencing blood pressure, such as the renin angiotensin system, the heart, the kidney and the blood vessels, has generated the hope that vitamin D therapy could be a new target for the treatment for hypertensive patients. Cross-sectional studies have clearly shown an association between low levels of vitamin D and hypertension. This association is not as clear in longitudinal studies. Finally, evidence from randomized controlled trials specifically designed to test the hypothesis of a blood pressure lowering effect of vitamin D is weak. Therefore, there is actually not enough evidence to recommend giving vitamin D to reduce blood pressure in hypertensive patients.
Assuntos
Hipertensão/patologia , Receptores de Calcitriol/efeitos dos fármacos , Sistema Renina-Angiotensina/efeitos dos fármacos , Vitamina D/uso terapêutico , Vitaminas/uso terapêutico , Pressão Sanguínea/efeitos dos fármacos , Sistema Cardiovascular/efeitos dos fármacos , HumanosRESUMO
BACKGROUND: Positron emission tomography (PET) during the cold pressor test (CPT) has been used to assess endothelium-dependent coronary vasoreactivity, a surrogate marker of cardiovascular events. However, its use remains limited by cardiac PET availability. As multidetector computed tomography (MDCT) is more widely available, we aimed to develop a measurement of endothelium-dependent coronary vasoreactivity with MDCT and similar radiation burden as with PET. METHODS AND RESULTS: A study group of 18 participants without known cardiovascular risk factor (9F/9M; age 60±6 years) underwent cardiac PET with (82)Rb and unenhanced ECG-gated MDCT within 4h, each time at rest and during CPT. The relation between absolute myocardial blood flow (MBF) response to CPT by PET (ml·min(-1)·g(1)) and relative changes in MDCT-measured coronary artery surface were assessed using linear regression analysis and Spearman's correlation. MDCT and PET/CT were analyzed in all participants. Hemodynamic conditions during CPT at MDCT and PET were similar (P>0.3). Relative changes in coronary artery surface because of CPT (2.0-21.2%) correlated to changes in MBF (-0.10-0.52ml·min(-1)·g(1)) (ρ=0.68, P=0.02). Effective dose was 1.3±0.2mSv for MDCT and 3.1mSv for PET/CT. CONCLUSIONS: Assessment of endothelium-dependent coronary vasoreactivity using MDCT CPT appears feasible. Because of its wider availability, shorter examination time and similar radiation burden, MDCT could be attractive in clinical research for coronary status assessment.
Assuntos
Vasos Coronários/fisiologia , Tomografia Computadorizada Multidetectores , Tomografia por Emissão de Pósitrons , Radioisótopos de Rubídio , Sistema Vasomotor/fisiologia , Idoso , Vasos Coronários/diagnóstico por imagem , Endotélio Vascular/diagnóstico por imagem , Endotélio Vascular/fisiologia , Estudos de Viabilidade , Feminino , Hemodinâmica/fisiologia , Humanos , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Músculo Liso Vascular/diagnóstico por imagem , Músculo Liso Vascular/fisiologia , Fluxo Sanguíneo Regional/fisiologia , Ultrassonografia , Sistema Vasomotor/diagnóstico por imagemRESUMO
The prevalence of resistant hypertension ranges between 5-30%. Patients with resistant hypertension are at increased risk of cardiovascular events. Radiofrequency renal denervation is a recent and promising technique that can be used in the setting of resistant hypertension. However, long-term safety and efficacy data are lacking and evidence to use this procedure outside the strict setting of resistant hypertension is missing. The aim of the article is to propose a common work-up for nephrologists, hypertensiologists, cardiologists and interventional radiologists in order to avoid inappropriate selection of patients and a possible misuse of this procedure.
Assuntos
Denervação/métodos , Hipertensão/cirurgia , Comunicação Interdisciplinar , Rim/inervação , Terapia Combinada , Denervação/estatística & dados numéricos , Humanos , Hipertensão/diagnóstico , Hipertensão/etiologia , Hipertensão/terapia , Rim/cirurgia , Guias de Prática Clínica como Assunto , Terapia de Salvação , Falha de TratamentoRESUMO
Redox-based mechanisms play critical roles in the regulation of multiple cellular functions. NF-kappaB, a master regulator of inflammation, is an inducible transcription factor generally considered to be redox-sensitive, but the modes of interactions between oxidant stress and NF-kappaB are incompletely defined. Here, we show that oxidants can either amplify or suppress NF-kappaB activation in vitro by interfering both with positive and negative signals in the NF-kappaB pathway. NF-kappaB activation was evaluated in lung A549 epithelial cells stimulated with tumor necrosis factor alpha (TNFalpha), either alone or in combination with various oxidant species, including hydrogen peroxide or peroxynitrite. Exposure to oxidants after TNFalpha stimulation produced a robust and long lasting hyperactivation of NF-kappaB by preventing resynthesis of the NF-kappaB inhibitor IkappaB, thereby abrogating the major negative feedback loop of NF-kappaB. This effect was related to continuous activation of inhibitor of kappaB kinase (IKK), due to persistent IKK phosphorylation consecutive to oxidant-mediated inactivation of protein phosphatase 2A. In contrast, exposure to oxidants before TNFalpha stimulation impaired IKK phosphorylation and activation, leading to complete prevention of NF-kappaB activation. Comparable effects were obtained when interleukin-1beta was used instead of TNFalpha as the NF-kappaB activator. This study demonstrates that the influence of oxidants on NF-kappaB is entirely context-dependent, and that the final outcome (activation versus inhibition) depends on a balanced inhibition of protein phosphatase 2A and IKK by oxidant species. Our findings provide a new conceptual framework to understand the role of oxidant stress during inflammatory processes.
Assuntos
Peróxido de Hidrogênio/farmacologia , NF-kappa B/metabolismo , Oxidantes/farmacologia , Ácido Peroxinitroso/farmacologia , Fator de Necrose Tumoral alfa/farmacologia , Animais , Linhagem Celular Tumoral , Humanos , Quinase I-kappa B/metabolismo , Proteínas I-kappa B/metabolismo , Inflamação/metabolismo , Interleucina-1beta/metabolismo , Camundongos , Fosforilação/efeitos dos fármacos , Proteína Fosfatase 2/metabolismoRESUMO
Vitamin D deficiency , defined by a 25-OH vitamin D3 plasma level < 30 ng/ml, is highly prevalent in the population. Several observational studies have suggested that such a deficiency increases the risk of hypertension development. Vitamin D seems to have an inhibitory effect on renin secretion and might by this mechanism exert an antihypertensive effect. Recent randomized trials have failed however to demonstrate a blood pressure lowering effect of vitamin D supplementation.