Mean Difference In Blood Pressure Research Articles

Poor adherence to home blood pressure measurement schedule

Consensus dictates that devices used for home blood pressure (BP) measurement should be equipped with a memory to store readings, rather than trusting patients' logbooks. However, data entered in the memory rely on patients' adherence to measurement schedules. We investigated the number and relevance of deviations from the requested measurement schedule. We instructed 106 patients to perform 28 BP readings in a 2-week period with a memory-equipped electronic device. Patients were requested to note their scheduled BP values in their logbook and were not informed of the presence of a memory function. The concordance between all BP recordings in both memory and logbook was 90.1% of possible total scheduled readings. The difference in mean BP of all readings from memory compared with all readings from the logbook was -0.06 mmHg (95% confidence interval -0.79 to 0.68) systolic and -0.28 mmHg (95% confidence interval -0.97 to 0.40) diastolic. Unscheduled measurements were performed by 57.5% of patients. Missing scheduled readings in both logbook and memory were found in 34.0% of patients. Fictional data were present for 16.0% of patients. When comparing all individual BP readings from the memory and the logbook, 10.4% of patients were classified in another hypertension stratum according to the European Society of Hypertension criteria. In 23.6% of patients, we did not find any bias. In spite of the use of memory-equipped devices, to ensure patients' adherence to measurement schedules, patients still need proper instruction and a close watch.

Validation of Microlife BP W100 wrist device assessed according to the European Society of Hypertension and the British Hypertension Society protocols

The objective of this study was to determine the accuracy of the Microlife BP W100 device for blood pressure measurement. The device evaluations were performed in 85 participants, by using both the protocol of the European Society of Hypertension (ESH) and the protocol of the British Hypertension Society (BHS). Initially, the data from 33 participants were examined according to the ESH protocol. Furthermore, 52 participants were then enrolled to fulfill the BHS protocol requirements. In all participants, sequential same arm measurements were made by two trained observers. The device passed all three phases of the ESH protocol for systolic blood pressure (SBP) and diastolic blood pressure (DBP) and was graded A according to the criteria of the BHS protocol for both SBP and DBP. The A/A grade was achieved in low (<130/80 mmHg), medium (130-160/80-100 mmHg) and high (>160/100 mmHg) blood pressure categories. Mean blood pressure difference between BP W100 and observers in the 85 participants was 0.1+/-5.3 mmHg for SBP and 1.1+/-3.4 mmHg for DBP, and thus, the device also met the requirements of the Association for the Advancement of Medical Instrumentation. In conclusion, these data show that the Microlife BP W100 wrist monitor satisfied the recommended ESH accuracy levels and achieved A/A grade of the BHS protocol across a wide range of blood pressure.

Modulation of the Sinus Rate during Ventricular Fibrillation

During supraventricular and ventricular tachycardia, the arterial baroreflex predominates with minimal contribution from the cardiopulmonary reflex. To our knowledge, the role of the arterial baroreflex gain (BRG) during and immediately following termination of ventricular fibrillation (VF) has not been characterized. We hypothesized that (1) arterial BRG correlated with sinus node cycle length (SNCL) changes during VF, and that (2) the greater the arterial BRG, the greater the blood pressure (BP) recovery following successful defibrillation. Arterial BRG was assessed in 18 patients referred for the implantation of a defibrillator incorporating an atrial lead. The average SNCL was measured during the 5 seconds prior to VF induction and the last 5 seconds during VF before defibrillation. Percent SNCL change (%DeltaSNCL) was determined. Arterial BP recovery was calculated as the difference in mean BP following defibrillation compared to during VF. Arterial BRG ranged between -3 and 18 ms/mmHg. During VF, SNCL shortened in 11 patients (group A, mean %DeltaSNCL =-15%), and surprisingly lengthened in seven patients (group B, mean %DeltaSNCL = 5%). There was no correlation between %DeltaSNCL and arterial BRG. In fact, arterial BRG in group A was lower when compared with group B (P = 0.075). Similarly, there was no correlation between arterial BRG and BP recovery. We found no correlation between arterial BRG and %DeltaSNCL during VF, or BP recovery following defibrillation. Our findings of SNCL lengthening in 7 of 18 patients suggest that in some patients, arterial BRG plays a minor role during VF with a greater contribution from the cardiopulmonary BRG.

Telmisartan to Prevent Recurrent Stroke: The PRoFESS Study

Marc Fisher MD Kennedy Lees MD Section Editors In retrospect, the choice of PRoFESS as the acronym for this trial may be considered unwise. The dictionary definition of the verb “to profess” is “to declare or to claim, often insincerely or falsely.” What does PRoFESS declare and can we believe the claim? Blood pressure reduction initiated several months after stroke reduces cardiovascular complications, including recurrent stroke.1 Would earlier intervention be beneficial? To address this question, the Prevention Regimen for Effectively Avoiding Second Strokes (PRoFESS) trial evaluated the effects of therapy with the angiotensin receptor blocker, telmisartan. Blockade of the renin–angiotensin system is said to reduce the risk of stroke independent of blood pressure.2,3 Indeed, a small study of unusual design4 suggested that an angiotensin receptor blocker started soon after stroke reduced rates of death and cardiovascular events despite no blood pressure reduction. Telmisartan at 80 mg daily was compared with placebo in 20 392 patients with prior ischemic stroke. Because PRoFESS used a factorial design allowing comparison of 2 antiplatelet regimens, patients with hemorrhagic stroke were excluded. All patients received treatment for blood pressure control at the discretion of the investigators. The primary outcome was recurrent stroke. Secondary outcomes were major cardiovascular events and the incidence of new-onset diabetes. The median interval to randomization was 15 days poststroke and median follow-up was 2.5 years. Although 74% of participants had a history of hypertension, mean blood pressure at randomization was 144.1/83.8 mm Hg. During follow-up, blood pressure fell in both groups but more so in the telmisartan arm (mean blood pressure difference 3.8/2.0 mm Hg). The results strongly support the null hypothesis. Hazard ratios …

Hypertension and daytime hypotension found on ambulatory blood pressure is associated with fatigue following stroke and TIA

Fatigue affects up to 68% of subjects following stroke. In non-stroke patients, associations are reported between chronic fatigue and both hypertension and hypotension. We hypothesized that, in patients with stroke or transient ischaemic attack (TIA), an association may exist between fatigue and abnormal blood pressure (BP) detected on ambulatory monitoring. Subjects recruited from a secondary prevention clinic underwent 24-h ambulatory BP monitoring and completed a questionnaire including the Fatigue Severity Scale (FSS). One hundred subjects were included (51% female, mean age 69 years). Mean FSS was 3.6 and 42 has a FSS >4 indicative of significant fatigue. Mean daytime BP for all subjects was 134/74 (SD 16/11 mmHg). There was no significant difference in mean BP between patients with and those without significant fatigue. Patients with stroke suffered worse fatigue than those with TIA (mean FSS 3.8 vs. 3.0, P = 0.03). Twenty-four subjects were hypertensive (mean 24-h BP >145/90 mmHg), 26 had a lowest daytime diastolic BP (DBP) <50 mmHg and 4 had both. Fifty-four subjects were normotensive and these had a significantly lower mean FSS than either those with hypertension (mean FSS 3.2 vs. 4.2, P = 0.02, t-test) or those with low DBP (mean FSS 3.2 vs. 4.2, P = 0.01, t-test). Hypertensive subjects were more likely to be significantly fatigued [chi(2) 3.8, P = 0.05, OR 3.1 (1.1-8.3)] as were subjects with low daytime DBP [chi(2) 8.4, P = 0.004, OR 4.2 (1.5-11.1)]. In subjects who have suffered a stroke or TIA, fatigue is associated with measures of both hypertension and hypotension on ambulatory monitoring. Patients with stroke suffered worse fatigue than those with TIA.

Validation of the Microlife BP W200-1 wrist device for blood pressure measurement

The objective of the study was to determine the accuracy of the BP W200-1 device for blood pressure measurement at the wrist developed by the Microlife Company. The BP W200-1 model features a 'Microlife Average Mode', which uses a 'weighted' average of a minimum of three consecutive blood pressure (BP) readings taken 15 s apart. Device evaluation was carried out using the International Protocol of the European Society of Hypertension. Monitor performance was assessed in relation to patients' sex, age, wrist circumference, and systolic (SBP) and diastolic blood pressures (DBP). The BP W200-1 comfortably passed all three phases of the protocol for SBP and DBP. The device performed well in all ranges of SBP and DBP. Mean blood pressure differences for the BP W200-1 monitor were -1.2+/-4.5 mmHg for SBP and -0.2+/-3.1 mmHg for DBP. In multivariable analyses, the SBP and DBP discrepancies between device and observer were unrelated to age, sex, wrist circumference, and blood pressure level. These data show that the Microlife BP W200-1 wrist monitor satisfies the recommended European Society of Hypertension accuracy levels for SBP and DBP and therefore can be recommended for clinical use in the adult population. Its performance is uniform across subgroups of patients with different clinical characteristics.

Impact of maternal endothelial nitric oxide synthase gene polymorphisms on blood pressure, protein excretion and fetal outcome in pregnancy

A genetic association study was conducted to assess whether genetically determined alterations of the nitric oxide system are associated with clinical markers of pre-eclampsia. A large number of Caucasian women were consecutively included after delivery and genotyped for the endothelial nitric oxide synthase gene (NOS3) polymorphisms G894T, T789C (n=1502) and intron 4a/b (n=2186). There are no significant differences in mean blood pressure (BP), protein excretion or new-onset peripheral oedema between any of the genotypes over the course of pregnancy. Neither particular haplotypes nor the combined presence of any two alleles is associated with those markers of pre-eclampsia. The maternal polymorphisms do not seem to influence fetal growth, birth weight or the incidence of congenital malformations. We demonstrate in a large Caucasian population that maternal polymorphisms of the NOS3 gene are not related to clinical markers of pre-eclampsia. The functional relevance of the NOS3 variants alone does not seem to be strong enough to affect BP regulation during pregnancy.

A randomised trial of a 5 week, manual based, self-management programme for hypertension delivered in a cardiac patient club in Shanghai

BackgroundIn Shanghai there are 1.2 million people with hypertension, many of whom have difficulty in affording medical treatment. Community based, anti-hypertensive clubs have been created to provide health education but education alone is often ineffective. Lifestyle change programmes have shown some potential for reducing blood pressure but in previous trials have required specialist staff and extensive contact. We have previously demonstrated that self-management programmes delivered by health professionals, such as a nurse who has had short training in self-management techniques can change health behaviour and reduce symptoms. This study was designed to evaluate the benefits of a simple, cognitive-behavioural, self-management programme for hypertension based around a hypertension manual and delivered in the setting of a community anti-hypertensive club in Shanghai.MethodThe method was a pragmatic randomised controlled trial with an intention-to-treat analysis. Adult patients with mild-to-moderate primary hypertension, waiting to join a neighbourhood anti-hypertension club, were randomised to the self-management programme or to an information only control procedure. They attended the group treatment sessions on 4 occasions over 5 weeks for education combined with goal setting for lifestyle change and an introduction to exercise. The main outcome measures were: changes in blood pressure; blood total cholesterol; diet; activity level and health related quality of life 1 month and 4 months after the end of treatment.ResultsA total of 140 adults with mild-to-moderate primary hypertension took part. All of the main outcomes showed beneficial changes. Four months after the end of treatment the mean blood pressure differences between groups were systolic 10.15 mm Hg (P < 0.001, 95% CI 7.25–13.05), and diastolic 8.29 mmHg (P < 0.001, 95% CI 6.71–9.88). Patients in the intervention group also had significantly reduced weight, lowered blood total cholesterol, increased physical activity and improved quality of life.ConclusionPatients with mild-to-moderate primary hypertension attending a 5 week, group and manual based, cognitive-behavioural self-management programme, delivered through a voluntary club in Shanghai experienced a significant reduction in blood pressure.Trial registrationCurrent Controlled Trials ISRCTN73114566

Which physiological mechanism is responsible for the increase in blood pressure during leg crossing?

To determine which physiological mechanism is responsible for the blood pressure increase during leg crossing at knee-level in the sitting position. Finger blood pressure was measured with the Finometer in 102 participants (47 men) before and during leg crossing: 24 treated hypertensive patients, 50 diabetic individuals (25 with and 25 without antihypertensive medication) and 28 healthy volunteers. Mean age, 53 +/- 15 years (range 21-82 years). All participants crossed their legs at knee-level, with the upper part of the popliteal fossa on the suprapatellar bursa, in the sitting position. Differences in mean blood pressure, cardiac output, stroke volume, heart rate and total peripheral resistance were assessed with legs crossed versus legs uncrossed. Mean blood pressure [+3.3 +/- 5.5 mmHg; 95% confidence interval (CI) = 2.7-3.8], stroke volume (+7.6 +/- 5.4 ml; 95% CI = 6.7-8.6) and cardiac output (+0.4 +/- 0.9 l/min; 95% CI = 0.3-0.5) were significantly higher with legs crossed than in the uncrossed position, while the heart rate (-1.8 +/- 3.9 beats/min; 95% CI = -2.2 to -1.4) was significantly lower. Total peripheral resistance did not differ significantly (-0.01 +/- 0.16 AU; 95% CI = -0.03 to 0.00). The largest differences occurred in the hypertensive diabetic individuals, the smallest in the healthy volunteers. The changes were similar in men and women. There were no significant correlations in the total group between the differences of the hemodynamic variables and sex, age, body mass index or leg circumference. The study shows that higher blood pressure with legs in the crossed position is due to higher cardiac output and not to a higher total peripheral resistance.

Cardiorespiratory health effects associated with sulphurous volcanic air pollution

To investigate cardiorespiratory health effects associated with chronic exposure to volcanogenic sulphur dioxide (SO2) and fine sulphate particle (< or = 0.3 microm) air pollution emitted from Kilauea Volcano, Hawaii. Environmental-epidemiological cross-sectional study. An air study was conducted to measure exposure levels in the downwind area, and to confirm non-exposure in a reference area. Cross-sectional health data were collected from 335 adults, > or = 20 years of age, who had resided for > or = 7 years in the study areas. Prevalence was estimated for cardiorespiratory signs, and self-reported symptoms and diseases. Logistic regression analysis estimated effect measures between exposed and unexposed groups considering potential confounding including age, gender, race, smoking, dust and body mass index (BMI). Student's t-tests compared mean differences in blood pressure (BP), pulse and respiratory rates. There were statistically significant positive associations between chronic exposure and increased prevalence of cough, phlegm, rhinorrhoea, sore/dry throat, sinus congestion, wheezing, eye irritation and bronchitis. The magnitude of the associations differed according to SO2 and fine sulphate particulate exposure. Group analyses found no differences in pulse rate or BP; however, significantly faster mean pulse rates were detected in exposed non-medicated, non-smoking participants with BMI <25, and in participants aged > or = 65 years. Higher mean systolic BP was found in exposed participants with BMI <25. Long-term residency in active degassing volcanic areas may have an adverse effect on cardiorespiratory health in adults. Further study at Kilauea is recommended, and the authors encourage investigations in communities near active volcanoes worldwide. Public health interventions of community education, and smoking prevention and cessation are suggested.

Trimester‐specific blood pressure levels in relation to maternal pre‐pregnancy body mass index

We evaluated the influence of maternal pre-pregnancy body mass index (BMI), based on reported pre-pregnancy weight and height, on blood pressure (BP) levels during pregnancy by using information from a prospective cohort of 1733 women recruited before 20 weeks' gestation. Maternal antenatal BP values were abstracted from medical records, and we evaluated the mean BP differences according to BMI group in regression models, using generalised estimating equations to account for repeated BP records within each pregnancy. In each trimester, mean systolic BP (SBP) and diastolic BP (DBP) values were positively associated with maternal pre-gestational BMI. This association persisted after adjustment for maternal age, parity, smoking, education, marital status and physical activity. Overweight women (25-29 kg/m(2)) had first-, second- and third-trimester mean SBPs that were 8.1, 7.7 and 8.2 mmHg, respectively, higher than values observed in lean women (<20 kg/m(2)). Mean DBP values were 4.5, 5.4 and 5.6 mmHg higher for each successive trimester in overweight vs. lean women. Obese (>30 kg/m(2)) women consistently had the highest mean SBP and DBP values. Trimester-specific mean SBP values were 10.7-12.0 mmHg higher among obese women vs. lean women. Corresponding trimester-specific mean DBP values were 6.9-7.4 mmHg higher in obese vs. lean women. Similar patterns were observed when trimester-specific average mean arterial pressures were evaluated. Elevated pregnancy BPs associated with maternal pre-gestational BMI are consistent with a large body of literature that documents increased pre-eclampsia risk among overweight and obese women.

Validation of the HEM-780REL with easy wrap cuff for self-measurement of blood pressure according to the European Society of Hypertension International Protocol

We tested the accuracy of the HEM-780REL automatic blood pressure monitor with Easy Wrap Cuff. We used the International Protocol for validation of blood pressure measuring devices developed by the Working Group on Blood Pressure Monitoring of the European Society of Hypertension. Thirty-three adults over the age of 30 years participated to have 11 total participants in each of the three required blood pressure ranges for systolic and diastolic blood pressure. Sequential blood pressure readings were taken independently by trained observers using a mercury standard with appropriate size cuff. A third observer performed measurements with the test device. Analyses were performed according to International Protocol specifications for the 99 pairs of measurements. The device was given a pass/fail recommendation based on bands of accuracy compared with the mercury standard (within 5, 10, or 15 mmHg), as well as number of readings per participant within 5 mmHg. The mean blood pressure difference was 0.52+/-7.7 mmHg for systolic blood pressure and 0.39+/-4.7 mmHg for diastolic blood pressure. Twenty-four out of 33 participants had two out of three readings within 5 mmHg of the mercury standard for systolic blood pressure. Twenty-seven out of 33 participants had two out of three readings within 5 mmHg of the mercury standard for diastolic blood pressure. The device received a passing grade both for accuracy of individual measurements and for accuracy for individuals. The HEM-780REL with Easy Wrap Cuff performs accurately according to the standards of the International Protocol.

Slow graft function after pediatric renal transplantation from volunteer live donors

Slow graft function (SGF) may occur during the early post-transplant period. In this paper, we present our findings regarding SGF after pediatric renal transplantation and its predictive variables. From 1985 to 2004, a total of 300 pediatric renal transplants were performed at our institution. A total of 10 cases with SGF and 50 controls that were operated by the same surgeons were enrolled in this study. The mean age of the recipients and donors was 11.4 (3-15 yr) and 28.05 yr (20-50 yr), respectively. All kidneys were retrieved from living donors. We compared patients with SGF with controls regarding four independent variables: age difference between donors and recipients, serum hemoglobin difference between donors and recipients, mean blood pressure (systolic blood pressure + 2 [diastolic blood pressure]/3) difference between donors and recipients, and weight difference between donors and recipients. The mean age of recipients was 10.5 +/- 4.1 in SGF group and 11.6 +/- 2.5 in control group (p = 0.4). The differences between donors and recipients regarding weight and mean blood pressure in subjects with SGF were not higher than other patients (42 kg vs. 37.4 kg, p = 0.4; -3 mmHg vs. -4.1 mmHg, p = 0.8). The mean hemoglobin difference between donors and recipients was 6.3 +/- 2.1 g/dL in SGF group and 6.7 +/- 2.3 g/dL in control group (p = 0.6). The differences between donors and recipients regarding age, weight, mean blood pressure and serum hemoglobin level are not predictive variables for SGF.

The interarm blood pressure difference as predictor of cardiovascular events in patients with hypertension in primary care: cohort study

Objectives of this study were to measure the prevalence of a difference in blood pressure (BP) between arms and determine whether a difference is associated with increased risk of cardiovascular events or death. A prospective cohort study of 247 patients with hypertension was undertaken in one rural general practice in England. The main outcome measures were mean difference in BP between arms and new episodes of myocardial infarction, cerebrovascular event, onset of angina or peripheral vascular disease or death. A total of 57/247 (23%) patients had a mean difference in systolic BP between arms of >or=10 mm Hg and 8/247 (3%) had a mean difference of >or=20 mm Hg. A total of 15/247 (6%) patients had a mean difference in diastolic BP between arms of >or=10 mm Hg. Survival analysis after 4.7 years (range 3.3-5.9) showed a shorter mean survival time without event or death for patients with a difference in systolic BP of >or=10 mm Hg compared with a difference of <10 mm Hg (3.7 (95% confidence interval, 3.2-4.2) versus 4.8 (4.6-5.1) years; P<0.001; hazard ratio 2.5 (1.5-4.2), P=0.001). Difference in systolic BP of >or=10 mm Hg between arms is common in this primary care population and is associated with a shorter survival time to death or new cardiovascular event. Detection of a difference between arms may identify hypertensive patients at increased risk of cardiovascular events. Such an approach would allow more effective targeting of resources in primary prevention strategies.

Correlation between Soluble Endoglin, Vascular Endothelial Growth Factor Receptor-1, and Adipocytokines in Preeclampsia

Recent reports have demonstrated that soluble endoglin (sEng), an antiangiogenic protein thought to impair TGF-beta binding to receptors, and soluble vascular endothelial growth factor receptor (sVEGFR)-1 play important roles in the pathophysiology of preeclampsia (PE). Moreover, insulin resistance, which is greatly influenced by adipocytokines, characterizes PE. We examined possible links between sEng, VEGF, sVEGFR, and adipocytokines in the pathophysiology of PE. We performed a cross-sectional study in 30 PE patients and controls matched for gestational age and body mass index. Blood samples were collected soon after disease onset. We measured serum concentrations of leptin, adiponectin, sEng, VEGF, placental growth factor (PlGF), and sVEGFR [soluble fms-like tyrosine kinase 1 (sFlt-1) and soluble fetal liver kinase 1 (sFlk-1)], and examined the placental protein content of sEng and sFlt-1. sEng concentrations in PE patients (60.9 +/- 28.8 ng/ml) were significantly higher than those in controls (11.2 +/- 4.4 ng/ml). There was a significant correlation between sEng and sFlt-1 or PlGF. Moreover, there were significant differences in mean blood pressure between the high and low sEng groups, and in proteinuria between the high and low sFlt-1 groups, and significant differences in placental sEng and sFlt-1 contents between patients with and without severe hypertension or proteinuria. sEng was also correlated positively with adiponectin levels and negatively with the leptin to adiponectin ratio. Along with sFlt-1 and PlGF, sEng might play a role in the pathophysiology of PE, especially in elevating blood pressure, while the association with hypoadiponectinemia and the high leptin to adiponectin ratio in pregnancy seem to be risk factors for PE.

Glucose-potassium-insulin infusions in the management of post-stroke hyperglycaemia: the UK Glucose Insulin in Stroke Trial (GIST-UK)

Hyperglycaemia after acute stroke is a common finding that has been associated with an increased risk of death. We sought to determine whether treatment with glucose-potassium-insulin (GKI) infusions to maintain euglycaemia immediately after the acute event reduces death at 90 days. Patients presenting within 24 h of stroke onset and with admission plasma glucose concentration between 6.0-17.0 mmol/L were randomly assigned to receive variable-dose-insulin GKI (intervention) or saline (control) as a continuous intravenous infusion for 24 h. The purpose of GKI infusion was to maintain capillary glucose at 4-7 mmol/L, with no glucose intervention in the control group. The primary outcome was death at 90 days, and the secondary endpoint was avoidance of death or severe disability at 90 days. Additional planned analyses were done to determine any differences in residual disability or neurological and functional recovery. The trial was powered to detect a mortality difference of 6% (sample size 2355), with 83% power, at the 5% two-sided significance level. This study is registered as an International Standard Randomised Controlled Trial (number ISRCTN 31118803) The trial was stopped due to slow enrolment after 933 patients were recruited. For the intention-to-treat data, there was no significant reduction in mortality at 90 days (GKI vs control: odds ratio 1.14, 95% CI 0.86-1.51, p=0.37). There were no significant differences for secondary outcomes. In the GKI group, overall mean plasma glucose and mean systolic blood pressure were significantly lower than in the control group (mean difference in glucose 0.57 mmol/L, p<0.001; mean difference in blood pressure 9.0 mmHg, p<0.0001). GKI infusions significantly reduced plasma glucose concentrations and blood pressure. Treatment within the trial protocol was not associated with significant clinical benefit, although the study was underpowered and alternative results cannot be excluded.

Effects of different anesthetic techniques on antidiuretic hormone secretion during laparoscopic cholecystectomy

With the advent of minimally invasive surgery, laparoscopic cholecystectomy has become the standard treatment for symptomatic gallbladder disease. This study aimed to evaluate the effects of using high- versus low-pressure pneumoperitoneum with different anesthetic techniques on hemodynamics and antidiuretic hormone (ADH) secretion. For this prospective study, 60 patients scheduled for elective laparoscopic cholecystectomy were randomly recruited. They were classified into four equal groups: group 1 received general anesthesia with low insufflation pressure (7-9 mmHg); group 2 received general anesthesia with high insufflation pressure (13-15 mmHg); group 3 received general anesthesia in addition to epidural analgesia with low insufflation pressure; and group 4 received general anesthesia in addition to epidural analgesia with high insufflation pressure. Routine intraoperative monitoring was done. The study parameters included heart rate per minute, mean blood pressure (mmHg), and ADH levels (via blood samples) before anesthesia, after induction, 30 and 45 min after abdominal insufflation, and finally, 2 h postoperatively. The heart rate showed significant increases after pneumoperitoneum in group 2, as compared with the other three groups. Significant differences in mean blood pressure were observed between the study groups. In groups 1 and 4, mean arterial pressure (MAP) significantly decreased after 15 min, and this decrease persisted until the end of the study. In group 2, MAP significantly increased after 15, 30, 45, and 60 min and after 60 min postoperatively. In group 3, MAP significantly decreased after 30 min, and this decrease persisted 1 h after surgery. There were no significant differences in ADH levels before and after induction of anesthesia among any of the study groups. In groups 1 and 4, no statistically significant changes in ADH levels were observed throughout the study period except a mild increase in ADH levels 30 and 45 min after abdominal insufflation. In group 2, after pneumoperitoneum, there was statistically significant increase in ADH levels from the baseline value of 6.422 +/- 0.551 pmol/l to 7.749 +/- 0.635 pmol/l at 30 min and to 6.457 +/- 0.450 pmol/l at 45 min. In group 3, there was a statistically significant decrease in ADH levels from the baseline value of 6.551 +/- 0.356 pmol/l to 6.125 +/- 0.618 pmol/l at 30 min, to 6.118 +/- 0.491 pmol/l at 45 min, and to 6.169 +/- 0.676 pmol/l at 2 h after abdominal insufflation. Pneumoperitoneum can affect several homeostatic systems, leading to hemodynamic and hormonal stress responses. The use of general anesthesia plus epidural analgesia with low insufflation pressure, general anesthesia with low insufflation pressure, or general anesthesia plus epidural analgesia with high insufflation pressure is safe and effective in attenuating these responses.

Validation of Heine Gamma G7 (G5) and XXL-LF aneroid devices for blood pressure measurement

To determine the accuracy of the Gamma G7 (and G5 model) and XXL-LF aneroid sphygmomanometers developed by the Heine Company. Device evaluations were performed using the new protocol of the European Society of Hypertension. Monitor performance was assessed in relation to participants' sex, age, arm circumference, and systolic and diastolic blood pressures. The two sphygmomanometers were assessed in two different samples according to European Society of Hypertension requirements, which are based on four zones of accuracy differing from the mercury standard by 5, 10, 15 mmHg, or more. Both sphygmomanometers passed all three phases of the protocol for systolic blood pressure and diastolic blood pressure. Mean blood pressure difference between Gamma G7 sphygmomanometer and observers was -0.4+/-3.3 mmHg for systolic blood pressure and -0.5+/-2.6 mmHg for diastolic blood pressure. Mean differences for the Gamma XXL-LF sphygmomanometer were -0.3+/-3.7 and -1.0+/-2.6 mmHg, respectively. In multivariable analyses, the SBP discrepancies between both aneroid sphygmomanometers and observers were unrelated to age, sex, arm circumference and systolic blood pressure. For diastolic blood pressure, a borderline relationship was found only for arm circumference (P=0.057) with the Gamma G7 device. These data show that the Heine Gamma G7 and Gamma XXL-LF aneroid sphygmomanometers satisfy the new recommended ESH accuracy levels for both SBP and DBP. Their performance is uniform across subgroups of participants with different clinical characteristics.

Characterization of heart size and blood pressure in the vitamin D receptor knockout mouse

Our previous studies showed vitamin D deficiency results in increased cardiac contractility, hypertrophy and fibrosis and has profound effects on heart proteomics, structure and function in rat. In this study we found that the heart in vitamin D receptor knockout (VDR-KO) mice is hypertrophied. Six homozygous VDR knockout (−/−), six wild type (+/+) and six heterozygous (+/−) mice were fed a diet containing 2% Ca, 1.25% P and 20% lactose to maintain normal blood calcium and phosphate levels for 12 months. Tail-cuff blood pressure was performed on all mice. Blood pressure determinations showed no differences in systolic or mean blood pressure in WT (+/+), KO (−/−) or HETERO (+/−) mice at 3 and 6 months. However, decreased systolic BP in the KO mice relative to WT at 9 months of age was observed. ECG analysis showed no significant differences in the intact KO, HETERO or WT mice. The mice were killed at 12 months. Heart weight/body weight ratio was 41% (P<.003) greater in the KO mice versus WT and HETERO was 19% (P<.05) increased versus WT. Other VDR-KO tissues did not display hypertrophy. Cross sectional and longitudinal analysis of the heart myofibrils showed highly significant cellular hypertrophy in VDR-KO mice. Trichrome staining of heart tissue showed marked increase in fibrotic lesions in the KO mice. Analysis of plasma renin activity, angiotensin II (AII) and aldosterone levels showed elevated but not significantly different renin activity in KO versus WT and no significant differences in AII or aldosterone levels. Our data do not support the concept that the renin-angiotensin system or hypertension are the factors that elicit these changes. Data presented here reveal that ablation of the VDR signaling system results in profound changes in heart structure. We propose that calcitriol acts directly on the heart as a tranquilizer by blunting cardiomyocyte hypertrophy.

Abstract 4187: Glu27 β 2 -Adrenoceptor Polymorphism Enhances Body Weight Loss and 24h-Ambulatory Blood Pressure Reduction in Obese Women

Introduction: Obesity has been linked to genetic and environmental determinants. Glu27 β 2 -adrenoceptor polymorphism has been associated with obesity and hypertension. In addition, muscle vasodilatation during physiological maneuvers is increased in individuals with Glu27 β 2 -adrenoceptor polymorphism. Not known is the impact of hypocaloric diet and exercise training on body weight and blood pressure (BP) in obese individuals with Glu27 β 2 -adrenoceptor polymorphism. Methods: From an initial sampling of 216 volunteers, we studied 42 middle-age normotensive obese women selected to represent two genotypes: 19 with Glu27 β 2 -adrenoceptor polymorphism and 23 wild type Gln27 (883± vs 86±2kg, P30.48, respectively). Hypocaloric diet consisted of a 600kcal/day reduction. Exercise training consisted of three 60-min exercise session/week during 4 months. Twenty-four hour ambulatory BP, cardiac output (CO, carbon dioxide rebreathing), and muscle sympathetic nerve activity (MSNA, microneurography) were evaluated pre and post interventions. Results: Hypocaloric diet and exercise training significantly decreased body weight, body mass index (BMI), 24-hour systolic BP, 24-hour pulse pressure, and CO in Glu27 and Gln27 groups. However, the comparisons between groups showed that the reduction in body weight (10.7±1 vs 7.4±1kg, P =0.02), BMI (4.1±0.4 vs 2.8±0.2kg/m 2 , P =0.01), 24-hour systolic BP (5.1±1 vs 2.2±1mmHg, P =0.05), 24-hour pulse pressure (3.6±1 vs 1.5±1mmHg, P =0.01), and CO (0.8±0.2 vs 0.4±0.1L/min, P =0.04) were significantly greater in Glu27 group than in Gln27group. No significant differences in diastolic BP, mean BP, and MSNA levels between groups were found. Conclusions: Obese women with Glu27 of the β 2 -adrenoceptor are more susceptible to body weight loss, and BP and CO reduction after hypocaloric diet and exercise training than wild type Gln27 obese women.