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Systolic Blood Pressure (systolic + blood_pressure)
Kinds of Systolic Blood Pressure Selected AbstractsLower Systolic Blood Pressure Is Associated with Greater Mortality in People Aged 85 and OlderJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 10 2008Lena Molander Bsc OBJECTIVES: To investigate the association between blood pressure and mortality in very old people. DESIGN: Population-based cohort study. SETTING: County of Västerbotten, Sweden. PARTICIPANTS: Half of all subjects aged 85 and all of those aged 90 and 95 and older (N=348) in one urban and five rural municipalities in the north of Sweden. MEASUREMENTS: Among others, supine blood pressure, Mini-Mental State Examination, Barthel Index of activities of daily living, Mini Nutritional Assessment, and body mass index. Information on diagnoses, medications, and 4-year mortality was collected. Associations between blood pressure and mortality were investigated using Cox regression analyses, controlling for a number of diagnoses and health factors. RESULTS: Baseline systolic blood pressure (SBP), diastolic blood pressure, and pulse pressure were all inversely associated with mortality within 4 years according to univariate analysis. SBP was the strongest predictor. In Cox regression analyses, low SBP (,120 mmHg) correlated with greater 4-year all-cause mortality alone and when controlling for health status. This connection persisted after exclusion of deaths within the first year. There was a tendency toward a U-shaped mortality curve for the adjusted model, with SBP of 164.2 mmHg (95% confidence interval=154.1,183.8 mmHg) being associated with the lowest mortality. CONCLUSION: Lower SBP seems to be associated with greater mortality in people aged 85 and older, irrespective of health status. There are indications of a U-shaped correlation between SBP and mortality, and the optimal SBP for this age group could be above 140 mmHg. [source] Echocardiographic Estimation of Systemic Systolic Blood Pressure in Dogs with Mild Mitral RegurgitationJOURNAL OF VETERINARY INTERNAL MEDICINE, Issue 5 2006DACVIM, Sandra P. Tou DVM Background:Systemic hypertension is likely underdiagnosed in veterinary medicine because systemic blood pressure is rarely measured. Systemic blood pressure can theoretically be estimated by echocardiography. According to the modified Bernoulli equation (PG = 4v2), mitral regurgitation (MR) velocity should approximate systolic left ventricular pressure (sLVP), and therefore systolic systemic blood pressure (sSBP) in the presence of a normal left atrial pressure (LAP) and the absence of aortic stenosis. The aim of this study was to evaluate the use of echocardiography to estimate sSBP by means of the Bernoulli equation. Hypothesis:Systemic blood pressure can be estimated by echocardiography. Animal: Seventeen dogs with mild MR. No dogs had aortic or subaortic stenosis, and all had MR with a clear continuous-wave Doppler signal and a left atrial to aorta ratio of , 1.6. Methods:Five simultaneous, blinded continuous-wave measurements of maximum MR velocity (Vmax) and indirect sSBP measurements (by Park's Doppler) were obtained for each dog. Pressure gradient was calculated from Vmax by means of the Bernoulli equation, averaged, and added to an assumed LAP of 8 mm Hg to calculate sLVP. Results:Calculated sLVP was significantly correlated with indirectly measured sSBP within a range of 121 to 218 mm Hg (P= .0002, r= .78). Mean ± SD bias was 0.1 ± 15.3 mm Hg with limits of agreement of-29.9 to 30.1 mm Hg. Conclusion: Despite the significant correlation, the wide limits of agreement between the methods hinder the clinical utility of echocardiographic estimation of blood pressure. [source] A metabolic syndrome of hypertension, hyperinsulinaemia and hypercholesterolaemia in the New Zealand obese mouseEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 3 2000Ortlepp Background New Zealand obese (NZO) mice exhibit a polygenic obesity associated with hyperinsulinaemia and hyperglycaemia. Here we show that the strain presents additional features of a metabolic syndrome, i.e. elevated blood pressure, serum cholesterol and serum triglyceride levels. Materials and methods A back-cross model of NZO mice with the lean Swiss Jackson Laboratory (SJL) strain was established in order to investigate further the correlation between hypertension, obesity, serum insulin and hyperglycaemia. Results Systolic blood pressure was significantly elevated at 6 weeks of age and appeared to parallel the weight gain of the animals. Serum insulin levels, presumably reflecting insulin resistance, and systolic blood pressure values were significantly correlated with the body mass index (r2 = 0.707 and 0.486, respectively) in the back-cross mice. In contrast, blood pressure was only weakly correlated with serum insulin (r2 = 0.288) in non-diabetic mice, and was independent of serum insulin levels in diabetic animals. Conclusion The data are consistent with the concept that hypertension and insulin resistance are a characteristic consequence of the genetic constellation leading to obesity in the NZO strain, and that these traits reflect related mechanisms. It appears unlikely, however, that hypertension is a direct consequence of hyperinsulinaemia. [source] Two-thumb vs Two-finger Chest Compression in an Infant Model of Prolonged Cardiopulmonary ResuscitationACADEMIC EMERGENCY MEDICINE, Issue 10 2000Michele L. Dorfsman MD Abstract. Objective: Previous experiments in the authors swine lab have shown that cardiopulmonary resuscitation (CPR) using two-thumb chest compression with a thoracic squeeze (TT) produces higher blood and perfusion pressures when compared with the American Heart Association (AHA)-recommended two-finger (TF) technique. Previous studies were of short duration (1-2 minutes). The hypothesis was that TT would be superior to TF during prolonged CPR in an infant model. Methods: This was a prospective, randomized crossover experiment in a laboratory setting. Twenty-one AHA-certified rescuers performed basic CPR for two 10-minute periods, one with TT and the other with TF. Trials were separated by 2-14 days, and the order was randomly assigned. The experimental circuit consisted of a modified manikin with a fixed-volume arterial system attached to a neonatal monitor via an arterial pressure transducer. The arterial circuit was composed of a 50-mL bag of normal saline solution (air removed) attached to the manikin chest plate and connected to the transducer with a 20-gauge intravenous catheter and tubing. Rescuers were blinded to the arterial pressure tracing. Systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial pressure (MAP) were recorded in mm Hg, and pulse pressures (PPs) were calculated. Data were analyzed with two-way repeated-measures analysis of variance. Sphericity assumed modeling, with Greenhouse-Geisser and Huynh-Feldt adjustments, was applied. Results: Marginal means for TT SBP (68.9), DBP (17.6), MAP (35.3), and PP (51.4) were higher than for TF SBP (44.8), DBP (12.5), MAP (23.3), and PP (32.2). All four pressures were significantly different between the two techniques (p , 0.001). Conclusion: In this infant CPR model, TT chest compression produced higher MAP, SBP, DBP, and PP when compared with TF chest compression during a clinically relevant duration of prolonged CPR. [source] Salt-Sensitive Hypertension Resulting From Nitric Oxide Synthase Inhibition is Associated with Loss of Regulation of Angiotensin II in the RatEXPERIMENTAL PHYSIOLOGY, Issue 1 2002G. Hodge In the Dahl salt-sensitive hypertensive rat, a diet containing L-arginine, the natural substrate for nitric oxide synthase, abrogates the hypertension. We postulated that nitric oxide synthase inhibition might induce a salt-sensitive form of hypertension and that this salt sensitivity might be linked to a loss of the regulatory effect of sodium ingestion on angiotensin II (Ang II) and angiotensinogen. Male Wistar-Kyoto rats were randomised to a diet containing 0.008%, 2.2% or 4.4% sodium chloride and to treatment with the NO synthase inhibitor L-NAME (10 mg kg,1 day,1) in the drinking water, or drinking water alone (Controls) for 4 weeks. Blood pressure was measured by tail cuff plethysmography twice weekly. After 4 weeks, the rats were anaesthetised and truncal blood collected for determination of angiotensinogen, renin, angiotensin I (Ang I), Ang II and aldosterone concentrations as well as angiotensin-converting enzyme (ACE) activity. Systolic blood pressure increased with increasing dietary sodium intake in the L-NAME-treated rats (P < 0.05). Plasma renin and aldosterone concentrations decreased with increasing dietary sodium intake in both Control and L-NAME-treated rats. Ang I and ACE activity were unchanged by increasing dietary sodium intake. In contrast, the plasma concentration of Ang II and angiotensinogen increased with increasing dietary sodium (P < 0.05 and P < 0.005, respectively). Treatment with the Ang II receptor blocker, losartan, reversed the blood pressure increase. We conclude that treatment with L-NAME induces an increase in blood pressure that is at least in part salt sensitive. Further, the salt-sensitive component appears to be Ang II-dependent, as it was associated with increasing plasma Ang II levels and could be reversed by treatment with an Ang II receptor antagonist. [source] Blood pressure and vascular reactivity to endothelin-1, phenylephrine, serotonin, KCl and acetylcholine following chronic alcohol consumption in vitroFUNDAMENTAL & CLINICAL PHARMACOLOGY, Issue 3 2001Tijen Utkan Ethanol has been reported to cause hypertension, the mechanism of which is unknown. Therefore, the effect of chronic ethanol consumption on vascular responsiveness and blood pressure was investigated. Systolic blood pressure was recorded weekly by tail-cuff method. Aortic rings from rats fed chow ad libitum or pair-fed liquid diets containing either ethanol (7.2% v/v) or isocaloric carbohydrate for 4 weeks were placed in organ chambers for isometric tension measurement. There was a mild but significant elevation of the systolic blood pressure in the alcohol-fed rats by week 1 compared to baseline measurements and this remained higher. No significant changes in reactivity of rat isolated aortas to phenylephrine, serotonin, endothelin-1 (ET-1) and KCl were seen in chronic ethanol consumption. In addition, the sensitivity (i.e. pD2) of alcohol-fed aortic rings to the vasoconstrictors was also unchanged compared to controls. Chronic ethanol consumption, however, increased relaxation to acetylcholine with increased pD2 values, but did not alter relaxation to sodium nitroprusside, a cyclic guanosine monophosphate (cGMP)-dependent direct smooth muscle dilator. The results indicate that chronic ethanol consumption significantly potentiates endothelium-dependent relaxations in aortic rings, probably through interference with the production and/or the release of nitric oxide (NO) or adaptive alterations in muscarinic receptors on the endothelial cells, and that increased vascular responsiveness to several vasoconstrictors is not a mechanism responsible for the blood pressure elevation in the chronic alcohol consumption in rats. [source] New Beverage for Cardiovascular Health, Proposal Based on Oriental and Occidental Food Culture from a World-Wide Epidemiological StudyGERIATRICS & GERONTOLOGY INTERNATIONAL, Issue 2008Emilio Hideyuki Moriguchi Objectives: To investigate whether combined isoflavones and antioxidants in oriental and occidental drinks reduce the risk of cardiovascular disease (CVD) in high-risk Japanese immigrants living in Brazil. Materials and methods: From among over 100 Japanese immigrants thirty-seven females aged 45,60 years in Porto Alegre, Brazil, were randomized after informed consent into two groups to drink 200 ml of whole soy cell juice (S) containing 7.5 g soy protein and 10 mg of isoflavones (aglycone) in peach juice or placebo peach juice (P) with 80 Kcal for 12 weeks. Health survey including 24-hour urine (24 U) examination were carried out before the randomization and after the double blind placebo controlled intervention study. Results: Both weight and body mass index (BMI) were significantly (p < 0.05, 0.01) decreased from the baseline only in the S group. Systolic blood pressure (SBP) was decreased significantly (p < 0.05) from the baseline in the S group with elevated 24 U isoflavone excretion (>10 µmol), and there was a significant (p < 0.05) inter-group difference between the S and P groups after intervention. Total and low density lipoprotein (LDL)-cholesterol (C) decreased significantly (p < 0.05) in the S group from the baseline and there was a significant difference (p < 0.05) between the S and P groups after intervention. HbA1c and atherogenic index (non-high density lipoprotein (HDL)-C/HDL-C) were significantly (p < 0.05) decreased in both groups. Conclusions: Soy isoflavones combined with fruit antioxidants, the combination of which might potentiate local nitric oxide (NO) affect, decreased SBP, total cholesterol and LDL-C. Peach juice itself improved blood glucose levels and the atherogenic index of the high-risk Japanese population in Brazil. [source] Does the experimental design capture the effects of complementary therapy?JOURNAL OF CLINICAL NURSING, Issue 4 2007A study using reflexology for patients undergoing coronary artery bypass graft surgery Aim., Our purpose was to pilot test whether reflexology may reduce anxiety in patients undergoing Coronary Artery Bypass Graft Surgery in Iceland. Background., Nurses need to study the effects of complementary therapies in general and particularly those that may be beneficial to decrease patients' anxiety. It has been assumed that reflexology lessens anxiety, but research is needed to substantiate such expectations. Design., A pilot study using randomized design with experimental and control groups. Methods., Nine patients were recruited and randomly assigned into groups with five patients assigned into an experimental group receiving reflexology for 30 minutes and four patients into control group which rested for 30 minutes. Anxiety and physiological variables were measured pre- and post-reflexology sessions once a day over five days. Results., The anxiety scores were lower for patients in the control group on all measures. Systolic blood pressure lowered significantly more in the control group than in the treatment group. No significant changes were observed for other variables. Patients' comments and responses overwhelmingly suggested increased well-being due to both experimental and control intervention. Conclusion., This study showed little evidence to support reflexology as a mean of reducing anxiety in CABG patients. Several methodological problems were identified that need to be considered further. Relevance to clinical practice., It is suggested that reflexology should be tailored to individual needs and research methods used that allow for capturing its holistic nature. Further scholarly work is warranted to explore several methodological issues in studying complementary therapies in a highly complex treatment situation. [source] Birth weight and cardiovascular risk factors in a cohort followed until 80 years of age: the study of men born in 1913JOURNAL OF INTERNAL MEDICINE, Issue 2 2004M. Eriksson Abstract. Objectives., To analyse whether there is a relation-ship between birth weight and cardiovascular risk factors given the influence of potential modifying factors from birth time, former generations and adult life. Design., Population-based cohort followed until 80 years of age. Setting., Sweden. Subjects., A total of 478 singleton men born in 1913 and participating in a population study in Gothenburg, Sweden, from age 50. Main outcome measures., Systolic blood pressure (SBP), antihypertensive treatment, incident diabetes mellitus, and serum total cholesterol, serum triglycerides and waist circumference as both continuous variables and in the highest quintiles of their distributions. Results., After adjustment for the influence of birth time variables, hereditary factors and anthropometric and socio-economic adult life variables, SBP decreased by 3.7 mmHg per 1000 g increase of birth weight, the prevalence of antihypertensive treatment decreased by 32%, diabetes decreased by 53%, serum total cholesterol decreased by 0.20 mmol L,1 and being in the top quintile of serum cholesterol decreased by 23%. The population risk percentage due to a birth weight ,3000 g was for all three outcomes 3.8% and for antihypertensive treatment, diabetes and cholesterol 0.2, 18 and 2.5%, respectively. Conclusions., Low birth weight thus seems to affect the development of increasing SBP, antihypertensive treatment, diabetes and high cholesterol even when potential effect modifiers from birth time, former generations and adult life were taken into account. In the general population, the risk percentage due to a birth weight ,3000 g was largest for diabetes. [source] Attenuation of ciclosporin-induced nephrotoxicity by dietary supplementation of seal oil in Sprague-Dawley ratsJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 11 2005Wei Yang Fish oil, rich in omega-3 (n-3) polyunsaturated fatty acids (PUFAs), has been reported to attenuate nephrotoxicity induced by ciclosporin (cyclosporine A). Harp seal oil is a rich source of n-3 PUFAs. This study investigated the ability of dietary seal oil to reduce nephrotoxicity caused by ciclosporin. Sprague-Dawley rats were maintained on a standard diet (with sunflower oil as lipid, SFO) or a diet enriched with seal oil (with 85% seal oil and 15% sunflower oil as lipid, SO) for four weeks before and four weeks after intravenous administration of ciclosporin (15 mg kg,1 daily). Kidney function was assessed by measuring blood urea nitrogen, creatinine clearance, urinary N -acetyl-1-,- d -glucosaminidase, 6-keto-prostaglandin F1,, thromboxane B2 and malondialdehyde. Systolic blood pressure (SBP) was monitored. Ciclosporin concentrations in blood were measured using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The fatty acid compositions of the diets and erythrocyte membranes were analysed by gas chromatography (GC). The results showed that nephrotoxicity was induced by ciclosporin in rats maintained on both SO and SFO diets. However, rats fed on SO diet endured less toxicity than those on SFO diet. The n-3 and n-6 PUFAs in the erythrocyte membrane of rats maintained on SO diet were found to be 10.79% and 11.93%, while those in rats maintained on SFO diet were found to be 1.67% and 22.71%, respectively. In conclusion, dietary supplementation of seal oil was found to reduce ciclosporin-induced nephrotoxicity in rats. [source] The optimal bolus dose of alfentanil for tracheal intubation during sevoflurane induction without neuromuscular blockade in day-case anaesthesiaACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 1 2008J. Y. KIM Background: The purpose of this study was to determine the optimal bolus dose of alfentanil required to provide successful intubating conditions following inhalation induction of anaesthesia using 5% sevoflurane and 60% nitrous oxide without neuromuscular blockade in adult day-case anaesthesia. Methods: Twenty-four adults, aged 18,60 years, undergoing general anaesthesia for short ambulatory surgery were enroled into the study. After vital capacity induction, with sevoflurane 5% and 60% nitrous oxide in oxygen, pre-determined dose of alfentanil was injected over 30 s. The dose of alfentanil was determined by modified Dixon's up-and-down method (2 ,g/kg as a step size). Ninety seconds after the end of bolus administration of alfentanil, the trachea was intubated. Systolic blood pressure, heart rate and SpO2 were recorded at anaesthetic induction, before, 1 min and 3 min after intubation. Results: The bolus dose of alfentanil for successful tracheal intubation was 10.7±2.1 ,g/kg in 50% of patients during inhalation induction. From probit analysis, 50% effective dose (ED50) and ED95 values (95% confidence limits) of alfentanil were 10.7 ,g/kg (8.0,12.9 ,g/kg) and 14.9 ,g/kg (12.9,31.1 ,g/kg), respectively. Conclusions: Using the modified Dixon's up-and-down method, the bolus dose of alfentanil for successful tracheal intubation was 10.7±2.1 ,g/kg in 50% of adult patients during inhalation induction using 5% sevoflurane and 60% nitrous oxide in oxygen without neuromuscular blocking agent in day-case anaesthesia. [source] The Effect of Angiotensin-Converting Enzyme Inhibitors of Left Atrial Pressure in Dogs with Mitral Valve RegurgitationJOURNAL OF VETERINARY INTERNAL MEDICINE, Issue 2 2010T. Ishikawa Background: Despite many epidemiological reports concerning the efficacy of angiotensin-converting enzyme (ACE) inhibitors in dogs with mitral regurgitation (MR), the hemodynamic effects of ACE inhibitor administration have not been fully evaluated. Objectives: To document left atrial pressure (LAP) in dogs with MR administered ACE inhibitors, in order to obtain interesting information about daily LAP changes with administration of ACE inhibitors. Animals: Five healthy Beagle dogs weighing 9.8 to 14.2 kg (2 males and 3 females; aged 2 years). Methods: Experimental, crossover, and interventional study. Chordae tendineae rupture was induced, and a radiotelemetry transmitter catheter was inserted into the left atrium. LAP was recorded for 72 consecutive hours during which each of 3 ACE inhibitors,enalapril (0.5 mg/kg/d), temocapril (0.1 mg/kg/d), and alacepril (3.0 mg/kg/d),were administered in a crossover study. Results: Averaged diurnal LAP was significantly, but slightly reduced by alacepril (P= .03, 19.03 ± 3.01,18.24 ± 3.07 mmHg). The nightly drops in LAP caused by alacepril and enalapril were significantly higher than the daily drops (P= .03, ,0.98 ± 0.19 to ,0.07 ± 0.25 mmHg, and P= .03, ,0.54 ± 0.21,0.02 ± 0.17 mmHg, respectively), despite the fact that the oral administrations were given in the morning. Systolic blood pressure (122.7 ± 14.4,117.4 ± 13.1 mmHg, P= .04) and systemic vascular resistance (5800 ± 2685,5144 ± 2077 dyne × s/cm5, P= .03) were decreased by ACE inhibitors. Conclusions and Clinical Importance: ACE inhibitors decrease LAP minimally, despite reductions in left ventricular afterload. ACE inhibitors should not be used to decrease LAP. [source] Dietary NaCl Does Not Affect Blood Pressure in Healthy CatsJOURNAL OF VETERINARY INTERNAL MEDICINE, Issue 4 2004Nicole Luckschander The purpose of this study was to assess the effects of dietary salt intake on systolic blood pressure, water intake, urine output, and urine concentration in cats. Ten healthy young adult cats (mean age 2.5 years) were randomly divided into 2 groups and fed either a control diet (0.46% Na and 1.33% Cl on a dry matter [DM] basis) or a diet with a moderately increased salt content (1.02% Na and 2.02% Cl on a DM basis) for 2 weeks. After a 1-week wash-out period, each group was switched to the opposite diet for 2 weeks. During each 2-week study period, food and water intake, urine volume, urine specific gravity, and urine osmolality were measured daily. Systolic blood pressure (calculated as the mean of 5 readings measured with a Doppler flow detector) was assessed twice daily. No significant effect of diet composition was found on systolic blood pressure, and blood pressure measurements remained within reference limits throughout the study in all 10 cats. However, animals fed the higher salt diet had significantly increased water intake and urine osmolality, and significantly decreased urine specific gravity in comparison to animals fed the control diet. Examination of results of this preliminary study suggests that feeding a diet with moderately increased salt content increases water intake and causes diuresis without increasing systolic blood pressure in healthy adult young cats. [source] Immediate blood pressure-lowering effects of aerobic exercise among patients with chronic kidney diseaseNEPHROLOGY, Issue 7 2008SAMUEL A HEADLEY SUMMARY: Aim: The current study was designed to determine the effect of moderate-intensity aerobic exercise on blood pressure responses within the laboratory for 60 min post exercise and in the subsequent 24 h period in patients with chronic kidney disease. Methods: Twenty-four subjects with stages 2,4 chronic kidney disease (age = 54.5 ± 15.2 years, body mass index = 32.0 ± 5.9 kg/m2) on antihypertensive medication completed this study. In random counterbalanced order, subjects were asked to either walk for 40 min at 50,60% VO2peak (oxygen consumption) or, on a separate day, to sit quietly in the laboratory for the same length of time. Following exercise or the non-exercise period, blood pressure was taken at 10 min intervals for 60 min. Subjects then wore an ambulatory blood pressure monitor for the next 24 h. Results: Systolic blood pressure (mmHg) was reduced by 6.5 ± 10.8 compared with the pre-exercise baseline value (130.3 ± 21.1) in the laboratory after exercise and this was greater than after the control period (0.73 ± 10.3, P < 0.05). Diastolic blood pressure (mmHg) was reduced following exercise (2.5 ± 6.4) compared with the control period (2.1 ± 4.9, P < 0.05). The mean 24 h readings did not differ between exercise or non-exercise days. Conclusion: Acute aerobic exercise leads to reduced blood pressure for at least 60 min within the laboratory in chronic kidney disease patients. [source] Vagal dysfunction in irritable bowel syndrome assessed by rectal distension and baroreceptor sensitivityNEUROGASTROENTEROLOGY & MOTILITY, Issue 4 2008R. Spaziani Abstract, Autonomic nervous system dysfunction has been implicated in the pathophysiology of irritable bowel syndrome (IBS). This study characterized the autonomic response to rectal distension in IBS using baroreceptor sensitivity (BRS), a measure of autonomic function. Rectal bag pressure, discomfort, pain, ECG, blood pressure and BRS were continuously measured before, during and after rectal distension in 98 healthy volunteers (34 ± 12 years old, 52 females) and 39 IBS patients (39 ± 11 years old, 35 females). In comparison with the healthy volunteers, IBS patients experienced significantly more discomfort (69 ± 2.2% vs 56 ± 3.6%; P < 0.05), but not pain (9 ± 1.4% vs 6 ± 2.4%; ns) with rectal distension despite similar distension pressures (51 ± 1.4 vs 54 ± 2.4 mmHg; ns) and volumes (394 ± 10.9 vs 398 ± 21.5 mL; ns). With rectal distension, heart rate increased in both healthy volunteers (66 ± 1 to 71 ± 1 bpm; P < 0.05) and IBS patients (66 ± 2 to 74 ± 3 bpm; P < 0.05). Systolic blood pressure also increased in both healthy volunteers (121 ± 2 to 143 ± 2 mmHg; P < 0.05) and patients (126 ± 3 to 153 ± 4 mmHg (P < 0.05) as did diastolic blood pressure, 66 ± 2 to 80 ± 2 mmHg (P < 0.05), compared with 68 ± 3 to 84 ± 3 mmHg (P < 0.05) in IBS patients. The systolic blood pressure increase observed in IBS patients was greater than that seen in healthy volunteers and remained elevated in the post distension period (139 ± 3 mmHg vs 129 ± 2 mmHg; P < 0.05). IBS patients had lower BRS (7.85 ± 0.4 ms mmHg,1) compared with healthy volunteers (9.4 ± 0.3; P < 0.05) at rest and throughout rectal distension. Greater systolic blood pressure response to rectal distension and associated diminished BRS suggests a compromise of the autonomic nervous system in IBS patients. [source] Chest pain is inversely associated with blood pressure during exercise among individuals being assessed for coronary heart diseasePSYCHOPHYSIOLOGY, Issue 2 2007Blaine Ditto Abstract Acute and chronic increases in blood pressure have been related to decreases in pain perception. This phenomenon has been studied primarily using acute experimental pain stimuli. To extend the literature to naturalistic pain and in particular the problem of silent cardiac ischemia, this study examined the relationship between blood pressure and chest pain during exercise stress testing. Nine hundred seven (425 men, 482 women) individuals undergoing exercise stress testing for diagnosis of possible myocardial ischemia completed the McGill Pain Questionnaire (MPQ) immediately afterward and other questionnaires before and after testing. Blood pressure was measured before, during, and after exercise. Systolic blood pressure at the end of exercise was inversely related to a number of measures of pain such as total score on the MPQ. The relationship could not be explained by individual differences in exercise duration, medication use, sex, or other measured variable. In sum, the inverse relationship between blood pressure and sensitivity to pain that has been observed in other populations in experimental and naturalistic conditions was observed for chest pain during exercise. Blood pressure may contribute to episodes of silent ischemia. [source] Obesity is Associated with Worsening Cardiovascular Risk Factor Profiles and Proteinuria Progression in Renal Transplant RecipientsAMERICAN JOURNAL OF TRANSPLANTATION, Issue 11 2005Kirsten A. Armstrong Obesity is associated with adverse cardiovascular (CV) parameters and may be involved in the pathogenesis of allograft dysfunction in renal transplant recipients (RTR). We sought the spectrum of body mass index (BMI) and the relationships between BMI, CV parameters and allograft function in prevalent RTR. Data were collected at baseline and 2 years on 90 RTR (mean age 51 years, 53% male, median transplant duration 7 years), categorized by BMI (normal, BMI , 24.9 kg/m2; pre-obese, BMI 25,29.9 kg/m2; obese, BMI , 30 kg/m2). Proteinuria and glomerular filtration rate (eGFRMDRD) were determined. Nine percent RTR were obese pre-transplantation compared to 30% at baseline (p < 0.001) and follow-up (25 ± 2 months). As BMI increased, prevalence of metabolic syndrome and central obesity increased (12 vs 48 vs 85%, p < 0.001 and 3 vs 42 vs 96%, p < 0.001, respectively). Systolic blood pressure, fasting blood glucose and lipid parameters changed significantly with BMI category and over time. Proteinuria progression occurred in 65% obese RTR (23 (13,59 g/mol creatinine) to 59 (25,120 g/mol creatinine)). BMI was independently associated with proteinuria progression (ß 0.01, p = 0.008) but not with changing eGFRMDRD. In conclusion, obesity is common in RTR and is associated with worsening CV parameters and proteinuria progression. [source] Human head exposure to a 37 Hz electromagnetic field: Effects on blood pressure, somatosensory perception, and related parametersBIOELECTROMAGNETICS, Issue 3 2004Sergio Ghione Abstract Previous studies have shown that exposure to an electromagnetic field (EMF) of 37 Hz at a flux density of 80 ,T peak enhances nociceptive sensitivity in mice. Here we examined the effects on pain sensitivity and some indexes of cardiovascular regulation mechanisms in humans by measuring electrical cutaneous thresholds, arterial blood pressure, heart rate and its variability, and stress hormones. Pain and tolerance thresholds remained unchanged after sham exposure but significantly decreased after electromagnetic exposure. Systolic blood pressure was significantly higher during electromagnetic exposure and heart rate significantly decreased, both during sham and electromagnetic exposure, while the high frequency (150,400 mHz) component of heart rate variability, which is an index of parasympathetic activity, increased as expected during sham exposure but remained unchanged during electromagnetic exposure. Cortisol significantly decreased during sham exposure only. These results show that exposure to an EMF of 37 Hz also alters pain sensitivity in humans and suggest that these effects may be associated with abnormalities in cardiovascular regulation. Bioelectromagnetics 25:167,175, 2004. © 2004 Wiley-Liss, Inc. [source] THERAPEUTIC EFFECT OF GREEN TEA EXTRACT ON ADVANCED GLYCATION AND CROSS-LINKING OF COLLAGEN IN THE AORTA OF STREPTOZOTOCIN DIABETIC RATSCLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 4 2006Pon Velayutham Anandh Babu SUMMARY 1The therapeutic effect of green tea extract (GTE) on the aortic collagen content and its characteristics were investigated in streptozotocin diabetic rats. 2Diabetes was induced in rats by a single intra peritoneal injection of streptozotocin (60 mg/kg bodyweight). Six weeks after diabetes induction, GTE was administered orally for four weeks (300 mg/kg bodyweight daily). Systolic blood pressure, blood glucose, anti-oxidant status, collagen content, extent of glycation, collagen linked fluorescence and aortic collagen solubility pattern were determined in experimental rats. 3At the end of the experimental period, there was a significant increase in the systolic blood pressure and blood glucose in diabetic rats. The lipid peroxides increased whereas glutathione and vitamin C levels were decreased in the serum of diabetic rats. The collagen content, extent of glycation, the advanced glycation end products (AGEs) and degree of cross-linking were increased in the aorta of diabetic rats. 4The oral administration of GTE to diabetic rats significantly reduced the systolic blood pressure and blood glucose. The level of lipid peroxides reduced and the content of glutathione and vitamin C increased in the serum of GTE treated diabetic rats. Green tea extract also impede the accumulation of aortic collagen, extent of glycation, formation of AGEs and cross-linking of collagen in diabetic rats. The antihyperglycemic, anti-oxidant and antiglycating effects of GTE ascribed for these beneficial effects. In conclusion, green tea may have therapeutic effect in the treatment of cardiovascular complications characterized by increased AGE accumulation and protein cross-linking associated with diabetes. [source] Phytosterol additives increase blood pressure and promote stroke onset in salt-loaded stroke-prone spontaneously hypertensive ratsCLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 12 2003Hiroshi Ogawa Summary 1.,To assess the effect of dietary phytosterol on stroke and the lifespan of salt-loaded stroke-prone spontaneously hypertensive rats (SHRSP), we investigated the effects of the addition of phytosterol to soybean oil (phytosterol content: 0.3%) on stroke onset, lifespan following onset of stroke and overall lifespan compared with canola oil (phytosterol content: 0.9%). 2.,Six-week-old male SHRSP were fed a test diet prepared by the addition of canola oil (CA diet), soybean oil (SO diet), soybean oil plus 0.6% phytosterol (SO + 0.06P diet) or soybean oil plus 4.5% phytosterol (SO + 0.45P diet) as a 10% fat source. 3.,Systolic blood pressure (SBP) increased in the SO + 0.06P and SO + 0.45P groups compared with the SO group and the increase was dependent on the amount of phytosterol added, indicating that the addition of phytosterol to soybean oil may promote an increase in SBP in salt-loaded SHRSP. 4.,The onset of stroke was shortest in the SO + 0.45P group and survival after the onset of stroke was shortest in the CA group. Consequently, the SO + 0.45P and CA groups showed marked lifespan shortening, indicating that a fivefold greater amount of phytosterol was required to produce an effect equivalent to that of canola oil. 5.,Investigation of the mRNA expression of ATP-binding cassette (ABC) transporters involved in intestinal phytosterol absorption indicated significant decreases in the intestinal mRNA expression of Abcg5 and Abcg8 in SHRSP and Wistar-Kyoto rats compared with Wistar rats. 6.,In conclusion, the addition of phytosterol to soybean oil elevated SBP and promoted the onset of stroke, which may cause a reduction in survival time. However, a fivefold greater amount of phytosterol was required to produce an effect that was equivalent to the survival time-shortening effect of canola oil. The significant decrease in the intestinal mRNA expression of Abcg5 and Abcg8 in SHRSP may be responsible, at least in part, for the unfavourable effects observed following the addition of phytosterol. [source] Effects Of Nitric Oxide Synthase Inhibition And Low-Salt Diet On Blood Pressure And Mesenteric Resistance Artery Remodelling In Genetically Hypertensive RatsCLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 9 2001Janet M Ledingham SUMMARY 1. Nitric oxide synthase (NOS)-inhibited genetically hypertensive (GH) rats on normal and low-sodium diets were additionally given valsartan or felodipine to establish whether low-Na intake would have extra beneficial effects on blood pressure and cardiovascular structure. 2. Male GH rats on normal or low-Na diets were treated with the NOS inhibitor NG -nitro- L -arginine methyl ester (L -NAME) from the age of 7 to 12 weeks and were given either valsartan (10 mg/kg per day) or felodipine (30 mg/kg per day). 3. Systolic blood pressure (SBP; tail-cuff) was measured weekly. At 12 weeks of age, mesenteric resistance arteries (MRA) were fixed by perfusion and embedded in Technovit (Heraeus Kulzer GmbH, Werheim, Germany). Serial sections were cut and stained. Stereological analysis was used to obtain MRA media width, lumen diameter, ratio of media width/lumen diameter (M/L) and medial cross-sectional area (CSA). Left ventricular (LV) mass was determined. 4. In GH L -NAME-treated rats on a normal diet, SBP was significantly reduced (P < 0.001) by valsartan and felodipine, as was LV mass (valsartan P < 0.001; felodipine P < 0.05). A low-Na diet with valsartan caused a further fall in SBP (P < 0.01) but, with felodipine, SBP increased in rats on a low-Na diet (P < 0.05). 5. Valsartan with the low-Na diet had no further effect on LV mass, but the felodipine-treated group on a low-Na diet had a lower LV mass (P < 0.05) than rats on a normal diet. 6. In MRA from the GH L -NAME + valsartan-treated group, there was hypotrophic inward remodelling; the M/L ratio was reduced (P < 0.001) compared with GH L -NAME-treated rats. The lumen was outwardly remodelled in the group on the low-Na diet. 7. The GH L -NAME + felodipine-treated group showed hypotrophic outward remodelling and a reduction in M/L ratio compared with the GH L -NAME-treated group (P < 0.001). A low-Na diet had no further effect on MRA. 8. A low-Na diet + valsartan had beneficial effects on SBP and MRA, where outward remodelling of the lumen occurred and, thus, resistance was reduced. In contrast, felodipine with a low-Na diet increased SBP, reduced LV mass and had no effect on MRA structure. Valsartan treatment with a low-Na diet confers extra benefits on blood pressure and MRA structure. [source] Vasopressin V1A Receptor Antagonism Does Not Reverse Adrenocorticotrophin-Induced Hypertension In The RatCLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 11 2000Tafline B Fraser SUMMARY 1. The role of arginine vasopressin (AVP) was examined in adrenocorticotrophin (ACTH)-induced hypertension in Sprague-Dawley rats using the non-peptide AVP V1a receptor antagonist OPC 21268. 2. In an acute study, six rats were pretreated with ACTH for 11 days and direct arterial blood pressure (4 h), plasma osmolality and electrolyte concentrations were measured after OPC 21268 gavage. In a chronic study, 40 rats were randomly divided into four groups: (i) sham injection + sham gavage; (ii) ACTH + sham gavage; (iii) sham injection + OPC 21268; or (iv) ACTH + OPC-21268 for 16 days. Systolic blood pressure (SBP), water intake, urine volume (UV), urine osmolality and electrolytes, food intake, bodyweight and plasma osmolality and electrolyte concentrations were measured. 3. In the acute study, direct mean arterial blood pressure did not change with OPC 21268 (122±2 and 120±3 mmHg at 0 and 240 min, respectively). 4. In the chronic study, OPC 21268 did not affect ACTH-induced rises in blood pressure (from 125±2 (control) to 145±5 mmHg (group 4) compared with 122±3 (control) to 149±5 mmHg (group2)). Water intake and UV increased (from 29±2 to 83±6 mL/day; and from 5±1 to 36±5 mL/day, respectively) and the change in bodyweight decreased from 0±2 to ,107±7 g. 5. These results suggest that AVP (at the V1a receptor) does not play a significant role in the maintenance of ACTH-induced hypertension. [source] Functional Capillary Rarefaction in Mild Blood Pressure ElevationCLINICAL AND TRANSLATIONAL SCIENCE, Issue 1 2008Cynthia Cheng Abstract Capillary rarefaction is described in patients with moderate-to-severe hypertension. The study objective was to determine if structural and/or functional capillary rarefaction is detectable and associated with endothelial dysfunction in patients with mild blood pressure elevation (HBP: Systolic blood pressure 130,160 mm Hg). Capillary density was quantified by direct capillaroscopy in 110 nondiabetic black and non-black subjects. Endothelial function was quantified by plethysmographic measures of flow-mediated vasodilation. Compared to normotensives (NBP: N = 90), functional capillary rarefaction was detected in HBP (N = 20; p < 0.001). Functional capillary density measures correlated with endothelial function (p < 0.001). Functional, but not structural, capillary rarefaction is detectable and associated with endothelial dysfunction in both black and non-black individuals with mild blood pressure elevation. [source] Subclinical thyroid dysfunction and blood pressure: a community-based studyCLINICAL ENDOCRINOLOGY, Issue 4 2006John P. Walsh Objective, Overt hypothyroidism and hyperthyroidism are associated with hypertension, but it is uncertain whether the same is true of subclinical hypothyroidism and hyperthyroidism. Design, subjects and measurements, Cross-sectional study of 2033 participants (aged 17,89 years) in the Busselton Thyroid Study who did not have a history of thyroid disease. Systolic blood pressure (SBP), diastolic blood pressure (DBP) and the prevalence of hypertension (defined as SBP 140 mmHg, DBP 90 mmHg or on treatment for hypertension) in subjects with thyroid dysfunction and euthyroid subjects were compared using linear regression models. Subjects with treated hypertension (N = 299) were excluded from analyses of SBP and DBP but included in analyses of hypertension prevalence. Results, Mean SBP, DBP and the prevalence of hypertension did not differ significantly between subjects with subclinical hypothyroidism (N = 105) and euthyroid subjects (N = 1859), nor did they differ between subjects with serum TSH concentrations in the upper reference range (2·0,4·0 mU/l; N = 418) and those with TSH concentrations in the lower reference range (0·4,2·0 mU/l; N = 1441). The prevalence of hypertension was higher in subjects with subclinical hyperthyroidism than euthyroid subjects (prevalence odds ratio 2·8, 95% confidence interval 1·3,6·0 adjusted for age, age2 and sex), but this was based on a small number of subjects with subclinical hyperthyroidism (N = 35). Conclusions, Subclinical hypothyroidism is not associated with hypertension. The observed association between subclinical hyperthyroidism and hypertension requires confirmation in a larger sample. [source] Corticosteroids and the cardiovascular response to stress: a pilot study of the 35% CO2 challenge in Addison's diseaseCLINICAL ENDOCRINOLOGY, Issue 3 2006J. M. Kaye Summary Objective, Glucocorticoids play an essential role in the neuroendocrine response to stress, influencing both the hypothalamic,pituitary,adrenal (HPA) axis and the sympatho-adrenomedullary (SAM) axis at several levels. In this pilot study, a clinical model of primary adrenocortical failure (Addison's disease, AD) has been used to evaluate the role of circulating glucocorticoids in both the autonomic and psychological response to stress. Design and subjects, Five subjects with known AD underwent a randomized, double-blind, placebo-controlled investigation in which they received fixed glucocorticoid plus mineralocorticoid hormone replacement or placebo for 48 h prior to a 35% CO2 challenge. Measurement, Psychological responses immediately before and after CO2 exposure were assessed by questionnaire. Systolic blood pressure (SBP) and heart rate were measured automatically at 1-min intervals for 5 min before and 5 min after the CO2 exposure. Results, While on hormone replacement, all subjects had an identical response to CO2 to that recorded in normal volunteers (initial bradycardia, an increase in blood pressure and subjective feelings of anxiety). On no replacement, however, the bradycardia and anxiety responses were not significantly altered, but the pressor response was markedly attenuated (+15·6 ± 5 mmHg on replacement compared with +4·2 ± 3·3 mmHg off replacement; P = 0·043). Conclusions, These data provide further evidence that the CO2 -induced bradycardia is a direct , presumably parasympathetic , response to CO2 independent of the pressor effect, and that the pressor response itself is dependent on the presence of the circulating corticosteroid. [source] Improvement In Blood Pressure Control With Impedance Cardiography-Guided Pharmacologic Decision MakingCONGESTIVE HEART FAILURE, Issue 1 2004Donald L. Sharman MD Previous reports have demonstrated improvement in blood pressure (BP) control utilizing noninvasive hemodynamic measurements with impedance cardiography (ICG). The purpose of this article is to report the effect of utilizing ICG-guided decision making to treat uncontrolled hypertension in a community generalist setting. Patient medical records were retrospectively reviewed for subjects on two antihypertensive agents with systolic blood pressure ,140 mm Hg or diastolic blood pressure ,90 mm Hg. All subjects were treated utilizing a previously published ICG-guided treatment algorithm. Twenty-one subjects met the BP and medication criteria. BP at entry was 157.2±13.9/78.7±9.9 mm Hg. Subjects were treated for 215±85 days (5.0±2.0 visits). After ICG-guided treatment, 12/21 (57.1%) achieved sustained BP control (p<0.001). BP was lowered to 141.6±22.0 (p<0.001)/77.1±10.7 (p>0.05) mm Hg. Antihypertensive agents increased from 2.0±0.0 to 2.5±0.7 (p<0.05). In this series of subjects with uncontrolled BP taking two antihypertensive agents, ICG-guided pharmacologic decision making resulted in significant reduction in BP and improvement in BP control. [source] Behavioral and cardiovascular effects of 7.5% CO2 in human volunteersDEPRESSION AND ANXIETY, Issue 1 2005Jayne E. Bailey M.Sc. Abstract The study of carbon dioxide (CO2) inhalation in psychiatry has a long and varied history, with recent interest in using inhaled CO2 as an experimental tool to explore the neurobiology and treatment of panic disorder. As a consequence, many studies have examined the panic-like response to the gas either using the single or double breath 35% CO2 inhalation or 5,7% CO2 inhaled for 15,20 min, or rebreathing 5% CO2 for a shorter time. However, this lower dose regime produces little physiological or psychological effects in normal volunteers. For this reason we have studied the effects of a higher concentration of CO2, 7.5%, given over 20 min. Twenty healthy volunteers were recruited to a double blind, placebo-controlled study where air and 7.5% CO2 were inhaled for 20 min. Cardiovascular measures and subjective ratings were obtained. When compared to air, inhaling 7.5% CO2 for 20 min increases systolic blood pressure and heart rate, indicating increased autonomic arousal. It also increases ratings of anxiety and fear and other subjective symptoms associated with an anxiety state. The inhalation of 7.5% CO2 for 20 min is safe for use in healthy volunteers and produces robust subjective and objective effects. It seems promising as an anxiety provocation test that could be beneficial in the study of the effects of anxiety on sustained performance, the discovery of novel anxiolytic agents, and the study of brain circuits and mechanisms of anxiety. Depression and Anxiety 00:000,000, 2005. © 2005 Wiley-Liss, Inc. [source] R-wave Amplitude in Lead II of an Electrocardiograph Correlates with Central Hypovolemia in Human BeingsACADEMIC EMERGENCY MEDICINE, Issue 10 2006John G. McManus MD Abstract Objectives Previous animal and human experiments have suggested that reduction in central blood volume either increases or decreases the amplitude of R waves in various electrocardiograph (ECG) leads depending on underlying pathophysiology. In this investigation, we used graded central hypovolemia in adult volunteer subjects to test the hypothesis that moderate reductions in central blood volume increases R-wave amplitude in lead II of an ECG. Methods A four-lead ECG tracing, heart rate (HR), estimated stroke volume (SV), systolic blood pressure, diastolic blood pressure, and mean arterial pressure were measured during baseline supine rest and during progressive reductions of central blood volume to an estimated volume loss of >1,000 mL with application of lower-body negative pressure (LBNP) in 13 healthy human volunteer subjects. Results Lower-body negative pressure resulted in a significant progressive reduction in central blood volume, as indicated by a maximal decrease of 65% in SV and maximal elevation of 56% in HR from baseline to ,60 mm Hg LBNP. R-wave amplitude increased (p < 0.0001) linearly with progressive LBNP. The amalgamated correlation (R2) between average stroke volume and average R-wave amplitude at each LBNP stage was ,0.989. Conclusions These results support our hypothesis that reduction of central blood volume in human beings is associated with increased R-wave amplitude in lead II of an ECG. [source] Cardiovascular responses to pacifier experience and feeding in newborn infantsDEVELOPMENTAL PSYCHOBIOLOGY, Issue 1 2001Morris Cohen Abstract This study examined the effects of sucking on a pacifier immediately before feeding on cardiovascular responses to feeding. Twenty-eight bottle-feeding infants were studied at 12 to 40 hr of age. Blood pressure and heart rate measurements were made during three periods: Period 1,while infants rested in their cribs before a regularly scheduled feeding, Period 2,while being held by the feeder immediately before feeding, and Period 3,during the first 3 to 5 min of feeding. Half of the infants were given a pacifier during Period 2. Blood pressures and heart rates increased across the periods; however, increases in systolic blood pressure during feeding were reduced for the group of infants given a pacifier prior to feeding. We suggest that cardiovascular responses to feeding in infants are comprised of multiple elements. Most of the systolic blood pressure responses to feeding are elicited by sucking whereas the heart rate response is dependent on both sucking and nutrient intake. © 2001 John Wiley & Sons, Inc. Dev Psychobiol 39: 34,39, 2001 [source] Treatment of isolated systolic hypertension in diabetes mellitus type 2DIABETES OBESITY & METABOLISM, Issue 4 2006Ingrid Os Age-related arterial stiffness is more pronounced in diabetics compared to non-diabetics, which could explain the prevalence of isolated systolic hypertension (ISH, systolic blood pressure ,140 mmHg and diastolic blood pressure <90 mmHg) being approximately twice that of the general population without diabetes. Large-scale interventional outcome trials have also shown that diabetics usually have higher pulse pressure and higher systolic blood pressure than non-diabetics. Advanced glycation end-product formation has been implicated in vascular and cardiac complications of diabetes including loss of arterial elasticity, suggesting possibilities for new therapeutic options. With increasing age, there is a shift to from diastolic to systolic blood pressure and pulse pressure as predictors of cardiovascular disease. This may affect drug treatment as different antihypertensive drugs may have differential effects on arterial stiffness that can be dissociated from their effects on blood pressure. While thiazide diuretics are associated with little or no change in arterial stiffness despite a robust antihypertensive effect, angiotensin converting enzyme inhibitors, angiotensin II receptor blockers and calcium-channel blockers have been shown to reduce arterial stiffness. However, combination therapy is nearly always necessary to obtain adequate blood pressure control in diabetics. There are no randomized controlled trials looking specifically at treatment of ISH in diabetics. Recommendations regarding treatment of ISH in diabetes mellitus type 2 are based on extrapolation from studies in non-diabetics, post-hoc analyses and prespecified subgroup analysis in large-scale studies, and metaanalysis. These analyses have clearly demonstrated that blood pressure lowering in ISH confers improved prognosis and reduced cardiovascular and renal outcomes in both diabetics and non-diabetics. [source] | ||||||||||||||||||||||||||||||||||||||||||||||