Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 51
Filtrar
1.
J Mech Behav Biomed Mater ; 141: 105752, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-36893688

RESUMEN

The arterial wall's tri-layered macroscopic and layer-specific microscopic structure determine its mechanical properties, which vary at different arterial locations. Combining layer-specific mechanical data and tri-layered modelling, this study aimed to characterise functional differences between the pig ascending (AA) and lower thoracic aorta (LTA). AA and LTA segments were obtained for n=9 pigs. For each location, circumferentially and axially oriented intact wall and isolated layer strips were tested uniaxially and the layer-specific mechanical response modelled using a hyperelastic strain energy function. Then, layer-specific constitutive relations and intact wall mechanical data were combined to develop a tri-layered model of an AA and LTA cylindrical vessel, accounting for the layer-specific residual stresses. AA and LTA behaviours were then characterised for in vivo pressure ranges while stretched axially to in vivo length. The media dominated the AA response, bearing>2/3 of the circumferential load both at physiological (100 mmHg) and hypertensive pressures (160 mmHg). The LTA media bore most of the circumferential load at physiological pressure only (57±7% at 100 mmHg), while adventitia and media load bearings were comparable at 160 mmHg. Furthermore, increased axial elongation affected the media/adventitia load-bearing only at the LTA. The pig AA and LTA presented strong functional differences, likely reflecting their different roles in the circulation. The media-dominated compliant and anisotropic AA stores large amounts of elastic energy in response to both circumferential and axial deformations, which maximises diastolic recoiling function. This function is reduced at the LTA, where the adventitia shields the artery against supra-physiological circumferential and axial loads.


Asunto(s)
Adventicia , Aorta Torácica , Porcinos , Animales , Aorta Torácica/fisiología , Estrés Mecánico , Fenómenos Biomecánicos , Adventicia/fisiología
3.
QJM ; 113(4): 258-265, 2020 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-31665476

RESUMEN

BACKGROUND: Vasopressin stimulates cyst growth in autosomal dominant polycystic kidney disease (ADPKD) and is a key therapeutic target. Evaluation of high water intake as an alternative to pharmacological vasopressin blockade is supported by patients. However feasibility, safety and adherence-promoting strategies required to deliver this remain unknown. AIMS: Assess the feasibility of a definitive randomized high water intake trial in ADPKD. METHODS: In this prospective open-label randomized trial, adult ADPKD patients with eGFR ≥ 20 ml/min/1.73 m2 were randomized to prescribed high water (HW) intake targeting urine osmolality (UOsm) ≤270 mOsm/kg, or ad libitum (AW) intake (UOsm >300 mOsm/kg). Self-management strategies including home-monitoring of urine-specific gravity (USG) were employed to promote adherence. RESULTS: We enrolled 42 participants, baseline median eGFR (HW 68.4 [interquartile range (IQR) 35.9-107.2] vs. AW 75.8 [IQR 59.0-111.0 ml/min/1.73 m2, P = 0.22) and UOsm (HW 353 [IQR 190-438] vs. AW 350 [IQR 240-452] mOsm/kg, P = 0.71) were similar between groups. After 8 weeks, 67% in the HW vs. 24% in AW group achieved UOsm ≤270 mOsm/kg, P = 0.001. HW group achieved lower UOsm (194 [IQR 190-438] vs. 379 [IQR 235-503] mOsm/kg, P = 0.01) and higher urine volumes (3155 [IQR 2270-4295] vs. 1920 [IQR 1670-2960] ml/day, P = 0.02). Two cases of hyponatraemia occurred in HW group. No acute GFR effects were detected. In total 79% (519/672) of USG were submitted and 90% (468/519) were within target. Overall, 17% withdrew during the study. CONCLUSION: DRINK demonstrated successful recruitment and adherence leading to separation between treatment arms in primary outcomes. These findings suggest a definitive trial assessing the impact of high water on kidney disease progression in ADPKD is feasible.


Asunto(s)
Ingestión de Líquidos , Riñón Poliquístico Autosómico Dominante , Agua , Adulto , Estudios de Factibilidad , Femenino , Tasa de Filtración Glomerular , Humanos , Masculino , Persona de Mediana Edad , Riñón Poliquístico Autosómico Dominante/metabolismo , Riñón Poliquístico Autosómico Dominante/fisiopatología , Riñón Poliquístico Autosómico Dominante/terapia , Estudios Prospectivos , Resultado del Tratamiento , Vasopresinas/antagonistas & inhibidores , Adulto Joven
4.
BMC Rheumatol ; 3: 33, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31410391

RESUMEN

BACKGROUND: The objective of this study was to explore the associations between ultrasonographic and radiographic joint scores and levels of arterial CVD risk markers in patients with osteoarthritis (OA). Secondly, to compare the levels of arterial CVD risk markers between OA phenotypes and controls. METHOD: The "Musculoskeletal pain in Ullensaker" Study (MUST) invited residents of Ullensaker municipality with self-reported OA to a medical examination. OA was defined according to the American College of Rheumatology (ACR) criteria and phenotyped based on joint distribution. Joints of the hands, hips and knees were examined by ultrasonography and conventional radiography, and scored for osteosteophytes. Hands were also scored for inflammation by grey scale (GS) synovitis and power Doppler (PD) signal. Control populations were a cohort of inhabitants of Oslo (OCP), and for external validation, a UK community-based register (UKPC).Pulse pressure augmentation index (AIx) and pulse wave velocity (PWV) were measured using the Sphygmocor apparatus (Atcor®). Ankel-brachial index (ABI) was estimated in a subset of patients. In separate adjusted regression models we explored the associations between ultrasonography and radiograph joint scores and AIx, PWV and ABI. CVD risk markers were also compared between phenotypes of OA and controls in adjusted analyses. RESULTS: Three hundred and sixty six persons with OA were included (mean age (range); 63.0 (42.0-75.0)), (females (%); 264 (72)). Of these, 155 (42.3%) had isolated hand OA, 111 (30.3%) had isolated lower limb OA and 100 (27.3%) had generalized OA. 108 persons were included in the OCP and 963 persons in the UKPC; (mean age (range); OCP: 57.2 (40.4-70.4), UKPC: 63.9 (40.0-75.0), females (%); OCP: 47 (43.5), UKPC: 543 (56.4%). Hand osteophytes were associated with AIx while GS and PD scores were not related to CVD risk markers. All OA phenotypes had higher levels of AIx compared to OCP in adjusted analyses. External validation against UKPC confirmed these findings. CONCLUSIONS: Hand osteophytes might be related to higher risk of CVD. People with OA had higher augmented central pressure compared to controls.Words 330.

5.
Hum Reprod ; 32(5): 985-992, 2017 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-28333321

RESUMEN

STUDY QUESTION: Are there differences in preconception cardiovascular function between women who have a viable pregnancy and those who have a first trimester miscarriage? SUMMARY ANSWER: Preconception cardiovascular function of central haemodynamics and arterial function are similar between women who have a viable pregnancy and those who have a first trimester miscarriage. WHAT IS KNOWN ALREADY: Miscarriages have been associated with increased long-term cardiovascular disease risk, and arterial and cardiovascular dysfunction has been hypothesised as the common link. It is not known if these risks are present prior to pregnancy or are a reflection of poor arterial and haemodynamic adaptation to pregnancy. STUDY DESIGN, SIZE, DURATION: This prospective longitudinal preconception cohort study was conducted over 18 months. In total, 367 participants were recruited pre-pregnancy, from which 197 pregnancies were recorded; 39 of these pregnancies ended in first trimester miscarriage. Complete longitudinal data were available for 172 pregnancies (140 viable pregnancies, 32 first trimester miscarriages) from pre-pregnancy to 6 weeks gestation. PARTICIPANTS/MATERIALS, SETTING, METHODS: This was a single site study based at a maternity hospital in London. Healthy women were recruited prior to natural conception and followed up once they became pregnant. All underwent haemodynamic [cardiac output (CO), peripheral vascular resistance (PVR)] and arterial function [aortic augmentation index (AIx) and pulse wave velocity (PWV)] testing prior to pregnancy and at 6 weeks gestation, using non-invasive devices (gas re-breathing method, Innocor® and an occilometric device, Vicorder®). Cross-sectional measurements at pre-pregnancy and 6 weeks gestation and a longitudinal analysis of changes were compared between women who had a subsequent viable pregnancy, and those who had a subsequent first trimester miscarriage. MAIN RESULTS AND THE ROLE OF CHANCE: There were no differences between women destined to have a healthy ongoing pregnancy compared to those who miscarried, in terms of baseline cardiovascular function, assessed by CO, PVR, PWV or AIx. Similarly, between the groups, there were no differences in pregnancy adaptation with similar trends in cardiovascular function changes from pre-pregnancy to 6 weeks gestation. LIMITATIONS, REASONS FOR CAUTION: Whilst this is the first study to investigate preconception and early pregnancy haemodynamic and arterial function in relation to viability, the relatively modest number of miscarriages may not be sufficient to show subtle differences in haemodynamic changes if these were present. WIDER IMPLICATIONS OF THE FINDINGS: This study suggests that pre-pregnancy haemodynamic and arterial function is unlikely to be the causal link between miscarriages and future cardiovascular disease. Our findings suggests that factors other than the presence of a viable embryo drive cardiovascular changes in early pregnancy. This study raises new questions about miscarriages as an independent risk event which predisposes women to increased cardiovascular risk later in life. STUDY FUNDING/COMPETING INTEREST(S): The investigators are funded by NIHR Imperial BRC, NIHR Cambridge BRC, Action Medical Research, Imperial College Healthcare Charity and Tommy's Charity. We acknowledge the loan of ultrasound equipment from Samsung Medison (South Korea)/MIS Ltd and provision of fertility monitors from SPD Development Company Ltd (Bedford, UK). There are no competing interests. C.C.L. is supported by the UK National Institute for Health Research Biomedical Research Centre based at Imperial College Healthcare National Health Service Trust and Imperial College London. TRIAL REGISTRATION NUMBER: N/A.


Asunto(s)
Aborto Espontáneo/fisiopatología , Presión Sanguínea/fisiología , Frecuencia Cardíaca/fisiología , Hemodinámica/fisiología , Primer Trimestre del Embarazo , Adulto , Estudios Transversales , Femenino , Humanos , Estudios Longitudinales , Embarazo , Estudios Prospectivos , Factores de Riesgo , Salud de la Mujer
6.
Ultrasound Obstet Gynecol ; 49(1): 78-84, 2017 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-27859800

RESUMEN

OBJECTIVE: Birth weight (BW) is thought to be determined by maternal health and genetic, nutritional and placental factors, the latter being influenced by anatomical development and perfusion. Maternal cardiovascular changes contribute to uteroplacental perfusion; however, they have not yet been investigated in relation to fetal growth or BW. Our aim was to explore the relationship between maternal cardiovascular adaptation, fetal growth and BW in healthy pregnancies. METHODS: This was a longitudinal prospective study of women planning to conceive a pregnancy. Maternal cardiac output (CO), cardiac index (CI), pulse-wave velocity, aortic augmentation index, central blood pressure and peripheral vascular resistance were assessed prior to pregnancy and at 6, 23 and 33 weeks' gestation. Fetal growth was assessed using serial ultrasound measurements of biometry. RESULTS: In total, 143 women volunteered to participate and were eligible for study inclusion. A total of 101 women conceived within 18 months and there were 64 live births with normal pregnancy outcome. There were positive correlations between BW and the pregnancy-induced changes in CO (ρ = 0.4, P = 0.004), CI (ρ = 0.3, P = 0.02) and peripheral vascular resistance (ρ = 0.3, P = 0.02). There were significant associations between second-to-third-trimester fetal weight gain and the prepregnancy-to-second-trimester increase in CO (Δ, 0.8 ± 1.2 L/min; ρ = 0.3, P = 0.02) and CI (Δ, 0.4 ± 0.6 L/min/m2 ; ρ = 0.3, P = 0.04) and reduction in aortic augmentation index (Δ, -10 ± 9%; ρ = -0.3, P = 0.04). CONCLUSIONS: In healthy pregnancy, incremental changes in maternal CO in early pregnancy are associated with third-trimester fetal growth and BW. It is plausible that this association is causative as the changes predate third-trimester fetal growth and eventual BW. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.


Asunto(s)
Peso al Nacer , Gasto Cardíaco/fisiología , Desarrollo Fetal , Adulto , Presión Sanguínea , Femenino , Humanos , Estudios Longitudinales , Embarazo , Segundo Trimestre del Embarazo , Estudios Prospectivos
7.
Curr Hypertens Rep ; 17(5): 36, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-25833457

RESUMEN

Hypertensive disorders of pregnancy affect approximately 5-10% of all maternities and are major contributors of maternal and neonatal morbidity and mortality worldwide. This group of disorders encompasses chronic hypertension, as well as conditions that arise de novo in pregnancy: gestational hypertension and pre-eclampsia. The latter group is thought to be part of the same continuum but with arbitrary division. Research into the aetiology of hypertension in pregnancy have largely been focused on pre-eclampsia, with a majority of studies exploring either pregnancy-associated factors such as placental-derived or immunologic responses to pregnancy tissue, or maternal constitutional factors such as cardiovascular health and endothelial dysfunction. The evidence base for the pathophysiology and progression of hypertensive disorders in pregnancy, particularly pre-eclampsia, is reviewed. Clinical algorithms and pharmacological agents for the management of hypertension in pregnancy are summarised, with a brief focus on post-partum considerations and long-term health implications. Novel therapeutic options for the management of pre-eclampsia are also explored.


Asunto(s)
Antihipertensivos/uso terapéutico , Hipertensión Inducida en el Embarazo/tratamiento farmacológico , Animales , Presión Sanguínea , Enfermedades Cardiovasculares/etiología , Femenino , Humanos , Placenta , Embarazo , Factores de Riesgo
8.
Br J Clin Pharmacol ; 80(1): 28-44, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25655310

RESUMEN

There is increasing evidence suggesting that epoxyeicosatrienoic acids (EETs) play an important role in cardioprotective mechanisms. These include regulating vascular tone, modulating inflammatory responses, improving cardiomyocyte function and reducing ischaemic damage, resulting in attenuation of animal models of cardiovascular risk factors. This review discusses the current knowledge on the role of EETs in endothelium-dependent control of vascular tone in the healthy and in subjects with cardiovascular risk factors, and considers the pharmacological potential of targeting this pathway.


Asunto(s)
Fenómenos Fisiológicos Cardiovasculares , Ácidos Hidroxieicosatetraenoicos/fisiología , Animales , Enfermedades Cardiovasculares/tratamiento farmacológico , Enfermedades Cardiovasculares/fisiopatología , Humanos , Ácidos Hidroxieicosatetraenoicos/biosíntesis , Ácidos Hidroxieicosatetraenoicos/genética , Terapia Molecular Dirigida
9.
J Hum Hypertens ; 27(7): 434-6, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23172028

RESUMEN

Unknown to its hypertension specialists, a major teaching hospital changed the cuffs on its sphygmomanometers from manufacturer-validated to a uniform washable alternative, in line with 'Health and Safety' concerns surrounding potential cross-contamination between patients. When clinic doctors suspected serious under-reading with the new cuffs, a systematic comparison was undertaken in 54 patients (mean±s.d. age, 61±17 years), using two UM-101 sphygmomanometers, one using the original, manufacturer-supplied cuff and the other with the washable replacement. The study confirmed an average under-reading of 8±10/5±5 mm Hg using the washable cuff, and a third of patients with poorly controlled hypertension were considered normotensive, after using this cuff. The UM-101 sphygmomanometers have now been re-fitted with the original cuffs. Sphygmomanometer cuffs are not interchangeable between devices and a modicum of common sense should be shown to prevent changes made in the name of Health and Safety from having the opposite effect to that intended.


Asunto(s)
Determinación de la Presión Sanguínea/instrumentación , Presión Sanguínea , Hipertensión/diagnóstico , Esfigmomanometros , Adulto , Anciano , Determinación de la Presión Sanguínea/efectos adversos , Determinación de la Presión Sanguínea/normas , Errores Diagnósticos , Diseño de Equipo , Femenino , Hospitales de Enseñanza , Humanos , Hipertensión/fisiopatología , Masculino , Persona de Mediana Edad , Seguridad del Paciente , Valor Predictivo de las Pruebas , Reproducibilidad de los Resultados , Esfigmomanometros/efectos adversos , Esfigmomanometros/normas
10.
Ultrasound Obstet Gynecol ; 40(6): 630-5, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-22858888

RESUMEN

OBJECTIVE: To determine the impact of ovulation and implantation timing on first-trimester crown-rump length (CRL) and the derived gestational age (GA). METHOD: One hundred and forty-three women who were trying to conceive were recruited prospectively. The timing of ovulation and implantation and the ovulation to implantation (O-I) interval were established in 101 pregnancies using home urinary tests for luteinizing hormone and human chorionic gonadotropin. In 71 ongoing pregnancies, GA determined by measurement of fetal CRL at 10-14 weeks' gestation was compared with GA based on ovulation and implantation day. First-trimester growth was determined by serial ultrasound scans at 6-7, 8-9 and 10-14 weeks. RESULTS: The median ovulation and implantation days were 16 and 27, respectively, with an O-I interval of 11 days. GA estimated from CRL at 10-14 weeks was on average 1.3 days greater than that derived from ovulation timing. CRL Z-score was inversely related to O-I interval (ρ= -0.431, P=0.0009). There was no significant relationship between CRL growth rate and the difference between observed CRL and expected CRL based on GA from last menstrual period (ρ=0.224, P=0.08). CONCLUSIONS: Early implantation leads to a larger CRL and late implantation to a smaller CRL at 10-14 weeks, independent of CRL growth rate. Implantation timing is a major determinant of fetal size at 10-14 weeks and largely explains the variation in estimates of GA in the first trimester derived from embryonic or fetal CRL.


Asunto(s)
Largo Cráneo-Cadera , Implantación del Embrión/fisiología , Desarrollo Fetal/fisiología , Ovulación/fisiología , Adulto , Femenino , Edad Gestacional , Humanos , Embarazo , Primer Trimestre del Embarazo , Estudios Prospectivos , Ultrasonografía Prenatal
11.
Placenta ; 33(7): 572-7, 2012 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-22538229

RESUMEN

OBJECTIVE: To assess the relationship between uterine artery Doppler pulsatility index (PI) and maternal global arterial stiffness and aortic stiffness in women at high a priori risk of preeclampsia in the late second trimester of pregnancy. METHODS: A prospective cohort study was performed. 99 women were recruited from the high-risk obstetric ultrasound clinic in the second trimester; median (±IQR) age and gestation were 33 (29-37) years and 23(+6) (23(+3)-24(+4)) weeks respectively. Transabdominal uterine artery Doppler was performed and mean values recorded. Women returned at a later date, median gestation (±IQR) 26(+5) (25(+6)-28(+0)) weeks, for measurement of blood pressure, augmentation index (AIx) and aortic pulse wave velocity (aPWV). RESULTS: Uterine artery PI is positively associated with both AIx (r = 0.4, P <0.0001, 95% CI: 0.22-0.55) and aPWV (r = 0.22, P = 0.03, 95% CI: 0.02-0.40). No relationship was found between uterine artery PI and mean arterial pressure or pulse pressure. AIx was significantly higher in women with uterine artery PI > 1.45 (P = 0.003, 95% CI: 3.1-14.9) but not aPWV (P = 0.45). AIx, but not aPWV, was significantly higher in women who developed preeclampsia (14% vs 9%, 95% CI: 2.0-8.6, P = 0.0018) or IUGR (11% vs 9%, 95% CI: 0.3-4.2, P = 0.027). AIx showed a negative correlation with birth weight z-score (r = -0.25, 95% CI: -0.43 to -0.06, P = 0.013). CONCLUSION: Increasing uterine artery Doppler PI reflects impaired placentation and increasing risk of preeclampsia. We show a positive association between uterine artery Doppler PI and both global arterial and aortic stiffness. We also show that increased maternal arterial stiffness is associated with a lower birth weight. These findings may represent evidence of an early effect of impaired placentation on the maternal vasculature. Alternatively, given the association between preeclampsia and later cardiovascular disease, ineffective placentation may result from impaired arterial function.


Asunto(s)
Edad Gestacional , Preeclampsia/fisiopatología , Embarazo de Alto Riesgo/fisiología , Arteria Uterina/fisiopatología , Rigidez Vascular/fisiología , Adulto , Peso al Nacer , Presión Sanguínea , Estudios de Cohortes , Femenino , Humanos , Placentación/fisiología , Preeclampsia/diagnóstico , Embarazo , Estudios Prospectivos , Flujo Pulsátil , Factores de Riesgo , Ultrasonografía , Arteria Uterina/diagnóstico por imagen
13.
Br J Surg ; 96(8): 865-9, 2009 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-19591159

RESUMEN

BACKGROUND: The physiological disturbances leading to lymphoedema after breast cancer surgery are poorly understood. Damage to sympathetic nerves during axillary lymph node dissection (ALND), leading to increased capillary fluid filtration, was investigated as a possible contributory factor. METHODS: The integrity of the upper limb sympathetic nervous system was tested in 36 patients before, and 3 and 12 months after ALND. Forearm vascular resistance (FVR), calculated from forearm blood flow and mean systemic arterial pressure, was measured before and after exposure to lower-body negative pressure. Forearm venous compliance was measured using (99m)Tc-labelled autologous erythrocytes and radionuclide plethysmography before and after cold water immersion of the feet. RESULTS: There were clear changes in FVR and venous compliance in response to sympathetic stimulation but no differences attributable to surgery or between the nine patients who developed lymphoedema and the 27 who did not; nor were there differences between the two arms. There was a trend towards lower preoperative FVR in patients who developed lymphoedema. CONCLUSION: Lymphoedema is not the result of sympathetic nerve damage sustained during ALND. Preoperative FVR may help predict who will get lymphoedema following this surgery.


Asunto(s)
Neoplasias de la Mama/cirugía , Escisión del Ganglio Linfático/efectos adversos , Linfedema/etiología , Sistema Nervioso Simpático/lesiones , Traumatismos del Sistema Nervioso/etiología , Adulto , Anciano , Anciano de 80 o más Años , Axila , Femenino , Antebrazo/irrigación sanguínea , Humanos , Persona de Mediana Edad , Periodo Posoperatorio , Cuidados Preoperatorios , Resistencia Vascular/fisiología
14.
Br J Radiol ; 82(973): 69-72, 2009 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-19095817

RESUMEN

Arterial calcification is well recognized as being associated with an increased risk of adverse cardiovascular events. Numerous methods for its quantification have been published, with no consensus on the technique used. In order to assess the reproducibility of a novel technique for quantifying aortic calcification, we measured the interobserver variability between two observers analysing the abdominal aortas of 34 volunteer patients. Using non-contrast abdominal CT images together with commercial imaging software, the quantity of calcium in a pre-determined section of aorta was calculated for each patient, and the difference in values obtained between the two observers compared using a Bland-Altman plot. Minimal interobserver variability was observed, with a significant difference in results occurring for only two patients. This protocol therefore represents a reliable technique that may be applied as a future standard in order to facilitate comparison between studies.


Asunto(s)
Enfermedades de la Aorta/diagnóstico por imagen , Calcinosis/diagnóstico por imagen , Aorta Abdominal/diagnóstico por imagen , Humanos , Variaciones Dependientes del Observador , Reproducibilidad de los Resultados , Tomografía Computarizada por Rayos X/métodos
16.
Thorax ; 63(4): 306-11, 2008 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-18024535

RESUMEN

RATIONALE: Chronic obstructive pulmonary disease (COPD) is associated with a 2-3-fold increase in the risk of ischaemic heart disease, stroke and sudden death. The mechanisms responsible for this association are not clear and appear to be independent of smoking history. OBJECTIVE: We test the hypothesis that patients with COPD have increased arterial stiffness and blood pressure in comparison with age and smoking matched controls. METHODS: In a prospective case control study, we recruited 102 patients with COPD and 103 healthy controls matched for age and smoking status. Patients were assessed by clinical history and spirometry, with arterial stiffness and blood pressure determined using radial artery applanation tonometry and sphygmomanometry. RESULTS: Patients with COPD had increased arterial stiffness compared with matched controls, with elevated augmentation pressure (17 (1) vs 14 (1) mm Hg; p = 0.005) and a reduced time to wave reflection (131 (1) vs 137 (2) ms; p = 0.004). These differences were associated with increases in both diastolic (82 (1) vs 78 (1) mm Hg; p = 0.005) and systolic blood pressure (147 (2) vs 132 (2) mm Hg; p<0.001). Serum C reactive protein concentrations were threefold higher in patients (6.1 (0.9) vs 2.3 (0.4) mg/l; p = 0.001). Data are presented as mean (SEM). CONCLUSIONS: Patients with COPD have increased arterial stiffness and blood pressure in comparison with controls matched for age and smoking status. We speculate that increased systemic inflammation and vascular dysfunction could potentially explain the excess cardiovascular morbidity and mortality associated with COPD.


Asunto(s)
Muerte Súbita Cardíaca/etiología , Isquemia Miocárdica/etiología , Enfermedad Pulmonar Obstructiva Crónica/complicaciones , Accidente Cerebrovascular/etiología , Estudios de Casos y Controles , Elasticidad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Isquemia Miocárdica/fisiopatología , Estudios Prospectivos , Enfermedad Pulmonar Obstructiva Crónica/fisiopatología , Pulso Arterial , Arteria Radial/fisiología , Factores de Riesgo , Accidente Cerebrovascular/fisiopatología , Resistencia Vascular/fisiología
17.
Eur J Clin Invest ; 35(12): 738-44, 2005 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-16313249

RESUMEN

BACKGROUND: Brachial blood pressure predicts cardiovascular outcome at rest and during exercise. However, because of pulse pressure amplification, there is a marked difference between brachial pressure and central (aortic) pressure. Although central pressure is likely to have greater clinical importance, very little data exist regarding the central haemodynamic response to exercise. The aim of the present study was to determine the central and peripheral haemodynamic response to incremental aerobic exercise. MATERIALS AND METHODS: Twelve healthy men aged 31 +/- 1 years (mean +/- SEM) exercised at 50%, 60%, 70% and 80% of their maximal heart rate (HRmax) on a bicycle ergometer. Central blood pressure and estimated aortic pulse wave velocity, assessed by timing of the reflected wave (T(R)), were obtained noninvasively using pulse wave analysis. Pulse pressure amplification was defined as the ratio of peripheral to central pulse pressure and, to assess the influence of wave reflection on amplification, the ratio of peripheral pulse pressure to nonaugmented central pulse pressure (PPP : CDBP-P1) was also calculated. RESULTS: During exercise, there was a significant, intensity-related, increase in mean arterial pressure and heart rate (P < 0.001). There was also a significant increase in pulse pressure amplification and in PPP : CDBP-P(1) (P < 0.001), but both were independent of exercise intensity. Estimated aortic pulse wave velocity increased during exercise (P < 0.001), indicating increased aortic stiffness. There was also a positive association between aortic pulse wave velocity and mean arterial pressure (r = 0.54; P < 0.001). CONCLUSIONS: Exercise significantly increases pulse pressure amplification and estimated aortic stiffness.


Asunto(s)
Aorta/fisiología , Arteria Braquial/fisiología , Ejercicio Físico/fisiología , Adulto , Análisis de Varianza , Presión Sanguínea/fisiología , Electrocardiografía , Frecuencia Cardíaca/fisiología , Humanos , Masculino , Manometría , Consumo de Oxígeno/fisiología , Pulso Arterial , Procesamiento de Señales Asistido por Computador
19.
Circulation ; 109(14): 1718-23, 2004 Apr 13.
Artículo en Inglés | MEDLINE | ID: mdl-15037536

RESUMEN

BACKGROUND: Endothelial vasomotor dysfunction and markers of systemic inflammation are independent determinants of cardiovascular risk. However, the link between clinical inflammation and endothelial dysfunction is unclear. The aim of this study was to use anti-neutrophil cytoplasmic antibody-associated systemic vasculitis (AASV) as a model of systemic inflammation in which to test the hypothesis that inflammation is associated with endothelial dysfunction and can be reversed with anti-tumor necrosis factor-alpha (TNF-alpha) therapy. METHODS AND RESULTS: Fourteen patients with active AASV and 21 age-matched control subjects were studied. Endothelial function was assessed through the use of forearm plethysmography and related to clinical disease activity: Birmingham Vasculitis Activity Score (BVAS) and serum levels of C-reactive protein (CRP), interleukin-6 (IL-6), and TNF-alpha. The effects of anti-TNF-alpha therapy (infliximab), either alone (n=6) or in combination with standard treatment (n=4), on endothelial function were subsequently determined. Patients had a mean BVAS of 11+/-1, and CRP and IL-6 were higher in the AASV group than in control subjects (34.8+/-10.5 versus 1.6+/-0.2 pg/mL, P<0.001; 9.0+/-0.7 versus 6.7+/-0.6 pg/mL, P=0.02). Forearm blood flow response to acetylcholine (ACh) was reduced in the patients compared with control subjects (P=0.002), but sodium nitroprusside (SNP) responses were not (P=0.3). The response to ACh improved with infliximab treatment (P=0.004) in particular, with infliximab alone (P=0.03). CONCLUSIONS: AASV is associated with endothelial dysfunction. Anti-TNF-alpha therapy, alone or in combination with standard treatment, results in clinical remission, reduced inflammation, and improved endothelium-dependent vasomotor responses.


Asunto(s)
Antiinflamatorios no Esteroideos/uso terapéutico , Anticuerpos Monoclonales/uso terapéutico , Enfermedades Autoinmunes/tratamiento farmacológico , Ácido Micofenólico/análogos & derivados , Factor de Necrosis Tumoral alfa/antagonistas & inhibidores , Vasculitis/tratamiento farmacológico , Antiinflamatorios no Esteroideos/administración & dosificación , Antiinflamatorios no Esteroideos/farmacología , Anticuerpos Anticitoplasma de Neutrófilos/análisis , Anticuerpos Monoclonales/administración & dosificación , Anticuerpos Monoclonales/farmacología , Enfermedades Autoinmunes/sangre , Enfermedades Autoinmunes/inmunología , Enfermedades Autoinmunes/fisiopatología , Proteína C-Reactiva/análisis , Síndrome de Churg-Strauss/sangre , Síndrome de Churg-Strauss/tratamiento farmacológico , Síndrome de Churg-Strauss/inmunología , Síndrome de Churg-Strauss/fisiopatología , Estudios de Cohortes , Ciclofosfamida/administración & dosificación , Ciclofosfamida/uso terapéutico , Quimioterapia Combinada , Endotelio Vascular/efectos de los fármacos , Inhibidores Enzimáticos/farmacología , Femenino , Antebrazo/irrigación sanguínea , Granulomatosis con Poliangitis/sangre , Granulomatosis con Poliangitis/tratamiento farmacológico , Granulomatosis con Poliangitis/inmunología , Granulomatosis con Poliangitis/fisiopatología , Humanos , Inmunosupresores/administración & dosificación , Inmunosupresores/uso terapéutico , Infliximab , Interleucina-6/sangre , Masculino , Persona de Mediana Edad , Ácido Micofenólico/administración & dosificación , Ácido Micofenólico/uso terapéutico , Óxido Nítrico/sangre , Óxido Nítrico Sintasa/antagonistas & inhibidores , Óxido Nítrico Sintasa de Tipo III , Proyectos Piloto , Pletismografía , Prednisolona/administración & dosificación , Prednisolona/uso terapéutico , Flujo Sanguíneo Regional/efectos de los fármacos , Factor de Necrosis Tumoral alfa/análisis , Vasculitis/sangre , Vasculitis/inmunología , Vasculitis/fisiopatología , omega-N-Metilarginina/farmacología
20.
Arthritis Rheum ; 50(2): 581-8, 2004 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-14872502

RESUMEN

OBJECTIVE: Arterial stiffness, an independent determinant of cardiovascular risk, is regulated by both structural and functional factors, including endothelium-derived nitric oxide. Endothelial dysfunction is associated with acute and chronic systemic inflammation. However, the role of systemic inflammation in arterial stiffening has not been determined. The aim of this study was to investigate the relationship between inflammation and arterial stiffness in patients with antineutrophil cytoplasmic antibody-associated systemic vasculitis (AASV) as a model of systemic inflammation. METHODS: Thirty-one patients with AASV (15 with active disease) and 32 age-matched controls were studied. Pulse wave velocity (PWV) and the augmentation index (AIx) were assessed noninvasively and related to serum levels of C-reactive protein (CRP), interleukin-6, and tumor necrosis factor alpha. RESULTS: In subjects with active disease, the AIx, PWV, and level of CRP were elevated compared with that in controls (mean +/- SEM 31 +/- 3% versus 22 +/- 2% [P = 0.003], 9.2 +/- 0.7 versus 7.5 +/- 0.3 meters/second [P = 0.03], and 16.0 +/- 4.0 versus 1.1 +/- 0.1 mg/liter [P < 0.001], respectively). However, PWV and the AIx were not significantly different between patients with disease in remission and controls (8.0 +/- 0.5 versus 7.5 +/- 0.3 meters/second and 19 +/- 3% versus 22 +/- 2%, respectively). The CRP level was positively correlated with both PWV and the AIx. Multiple regression analysis indicated that age, mean arterial pressure (MAP), and CRP were independently related to PWV, and that age, MAP, CRP, sex, and heart rate were associated with the AIx. CONCLUSION: These data indicate that AASV is associated with increased arterial stiffness, and that stiffness correlates with the degree of active inflammation.


Asunto(s)
Arteria Radial/fisiopatología , Vasculitis/fisiopatología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Anticuerpos Anticitoplasma de Neutrófilos/inmunología , Proteína C-Reactiva/metabolismo , Elasticidad , Femenino , Hemodinámica/fisiología , Humanos , Interleucina-6/sangre , Masculino , Persona de Mediana Edad , Flujo Pulsátil/fisiología , Factor de Necrosis Tumoral alfa/metabolismo , Vasculitis/sangre , Vasculitis/inmunología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...