Mean Difference In Systolic Blood Pressure Research Articles

Validation of the A&D UM-101 professional hybrid device for office blood pressure measurement according to the International Protocol

Assessment of the accuracy of the A&D UM-101 mercury-free professional device for auscultatory blood pressure (BP) measurement according to the European Society of Hypertension International Protocol. Further to auscultation, the device has a button to mark readings during deflation. Fifteen adults were included in phase 1 and another 18 in phase 2. Simultaneous BP measurements were taken by two observers (connected mercury sphygmomanometers) four times, sequentially with three measurements using the tested device (two connected tested devices, one used with and the other without the mark button). In phase 1, the device produced 44/45/45 measurements within 5/10/15 mmHg, respectively, for systolic BP (SBP) and 39/43/45 for diastolic (DBP). In phase 2.1, 87/97/99 measurements within 5/10/15 mmHg, respectively, for SBP, and 91/97/99 for DBP (using the mark button 65/93/98 for SBP and 76/96/99 for DBP). In phase 2.2, 29 participants had at least two of their SBP differences within 5 mmHg and none had any differences within 5 mmHg, whereas 32 and none, respectively, for DBP (with mark 24/4 participants for SBP; 29/1 for DBP). Mean SBP differences were -1.5+/-3.5 mmHg and DBP -1.3+/-3.0 (with mark -3.6+/-4.2 and -2.8+/-3.7). The difference in SBP measured by the tested device with versus without using the mark button was 3.0+/-3.3 mmHg (P<0.001) and DBP 1.9+/-2.5 mmHg (P<0.001). The device comfortably passed the validation protocol requirements. Using the mark button, the device, however, failed to meet the validation criteria. Therefore, it is recommended for clinical use without using the mark button.

Relaxation therapies for the management of primary hypertension in adults

Lifestyle interventions are often recommended as initial treatment for mild hypertension, but the efficacy of relaxation therapies is unclear. To evaluate the effects of relaxation therapies on cardiovascular outcomes and blood pressure in people with elevated blood pressure. We searched the Cochrane Library, MEDLINE, EMBASE, Science Citation Index, ISI Proceedings, ClinicalTrials.gov, Current Controlled Trials and reference lists of systematic reviews, meta-analyses and randomised controlled trials (RCTs) included in the review. RCTs of a parallel design comparing relaxation therapies with no active treatment, or sham therapy; follow-up >/=8 weeks; participants over 18 years, with raised systolic blood pressure (SBP) >/=140 mmHg or diastolic blood pressure (DBP) >/=85 mmHg); SBP and DBP reported at end of follow-up. participants were pregnant; participants received antihypertensive medication which changed during the trial. Two reviewers independently extracted data and assessed trial quality. Disagreements were resolved by discussion or a third reviewer. Random effects meta-analyses and sensitivity analyses were conducted. 29 RCTs, with eight weeks to five years follow-up, met our inclusion criteria; four were excluded from the primary meta-analysis because of inadequate outcome data. The remaining 25 trials assessed 1,198 participants, but adequate randomisation was confirmed in only seven trials and concealment of allocation in only one. Only one trial reported deaths, heart attacks and strokes (one of each). Meta-analysis indicated that relaxation resulted in small, statistically significant reductions in SBP (mean difference: -5.5 mmHg, 95% CI: -8.2 to -2.8, I2 =72%) and DBP (mean difference: -3.5 mmHg, 95% CI: -5.3 to -1.6, I2 =75%) compared to control. The substantial heterogeneity between trials was not explained by duration of follow-up, type of control, type of relaxation therapy or baseline blood pressure. The nine trials that reported blinding of outcome assessors found a non-significant net reduction in blood pressure (SBP mean difference: -3.2 mmHg, 95% CI: -7.7 to 1.4, I(2) =69%) associated with relaxation. The 15 trials comparing relaxation with sham therapy likewise found a non-significant reduction in blood pressure (SBP mean difference: -3.5 mmHg, 95% CI: -7.1 to 0.2, I(2) =63%). In view of the poor quality of included trials and unexplained variation between trials, the evidence in favour of causal association between relaxation and blood pressure reduction is weak. Some of the apparent benefit of relaxation was probably due to aspects of treatment unrelated to relaxation.

Cardiovascular Effects of Sibutramine: In Reply

We appreciate the comments by Dr Pisarik, because they illustrate the reason for the more in-depth analysis of blood pressure (BP) from our study published in Pediatrics .1 It is important to recognize that different statistical conclusions can result when different end points (ie, evaluation points) and statistical models are considered. The most important question, however, is how best to characterize the counterbalancing effects of sibutramine and weight loss on BP. In this study, the overall effect of sibutramine resulted in weight loss without meaningful adverse effects on BP. In our previous Annals of Internal Medicine article,2 a linear mixed-effects model for repeated measures (up to 17 visits per patient) that included baseline value as a covariate was used on change-from-baseline data to test for overall differences between treatment groups and for treatment differences at each visit. Small but statistically significant overall mean differences in systolic BP (SBP) (−0.9 mmHg [for sibutramine] vs −1.9 mmHg [for placebo]; P = .03) and diastolic BP (DBP) (+0.3 [for …

Validation of the Microlife WatchBP Home device for self home blood pressure measurement according to the International Protocol

Current guidelines recommend that self monitoring of blood pressure at home should only be performed using validated devices. This study assessed the accuracy of the Microlife WatchBP Home device for self home blood pressure measurement according to the European Society of Hypertension International Protocol. Thirty-three participants were included (15 in phase 1 and an additional 18 in phase 2). Simultaneous blood pressure measurements were taken by two observers (Y-tube-connected mercury sphygmomanometers) four times sequentially, with three measurements taken using the tested device. Absolute differences between observer and device measurements were classified into three zones (within 5, 10 and 15 mmHg). The number of measurements with a difference within 5 mmHg was calculated for each individual. In phase 1, the device produced 38, 43 and 43 measurements within 5, 10 and 15 mmHg, respectively, for systolic blood pressure and 35, 45 and 45 for diastolic blood pressure. In phase 2.1, the device produced 75, 91 and 97 measurements within 5, 10 and 15 mmHg for systolic, and 74, 93 and 99 for diastolic blood pressure. In phase 2.2, 30 participants had at least two of their differences within 5 mmHg and two participants had no differences within 5 mmHg for systolic blood pressure, whereas for diastolic blood pressure the number of participants were 27 and three, respectively. Mean difference for systolic blood pressure was -0.3+/-5.6 mmHg and for diastolic -2.4+/-4.8 mmHg. The Microlife WatchBP Home device for self home blood pressure measurement fulfills all the validation criteria of the International Protocol and can, therefore, be recommended for clinical use in the adult population.

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.

Validation of the Omron 705 IT oscillometric device for home blood pressure measurement in children and adolescents: The Arsakion School Study

Limited evidence exists on the accuracy of oscillometric devices for blood pressure measurement in children. This study validated the Omron 705 IT monitor (Omron Healthcare Europe BV, Hoofddorp, The Netherlands) in normotensive children and adolescents. Simultaneous blood pressure measurements were taken by two observers (connected mercury sphygmomanometers) four times, sequentially with three measurements by using the tested device. Absolute device-observer blood pressure differences were classified into three zones (within 5, 10 and 15 mmHg) and assessed using the European Society of Hypertension International Protocol criteria. The number of readings with a difference within 5 mmHg was calculated for each individual. The American Association for the Advancement of Medical Instrumentation criterion (mean difference+ or -SD <5+ or -8 mmHg) was also applied. A total of 197 study participants (591 readings) were included (99 boys, mean age+ or -SD 10.6+ or -2.4 years (range 6-16 years). The device produced 378 (64%), 532 (90%) and 579 (98%) measurements within 5, 10 and 15 mmHg, respectively, for systolic blood pressure, and 415 (70%), 525 (89%) and 577 (98%) measurements, respectively, for diastolic blood pressure. In all, 136 study participants (69%) had at least two systolic blood pressure differences within 5 mmHg and 16 (8%) had no differences within 5 mmHg (for diastolic blood pressure 147 (75%) and nine (5%) participants, respectively). Mean systolic blood pressure difference was 4.0+ or -4.8 mmHg and diastolic blood pressure -2.1+ or -5.9 mmHg and was <5+ or -8 mmHg in quartiles of participants divided by age, height, body mass index, arm circumference, blood pressure or pulse rate. The Omron 705 IT appears to be an accurate device for blood pressure measurement in normotensive children and adolescents.

Potassium supplementation for the management of primary hypertension in adults

Epidemiological evidence on the effects of potassium on blood pressure is inconsistent. To evaluate the effects of potassium supplementation on health outcomes and blood pressure in people with elevated blood pressure. We searched the Cochrane Library, MEDLINE, EMBASE, Science Citation Index, ISI Proceedings, ClinicalTrials.gov, Current Controlled Trials, CAB abstracts, and reference lists of systematic reviews, meta-analyses and randomised controlled trials (RCTs) included in the review. Inclusion criteria were: 1) RCTs of a parallel or crossover design comparing oral potassium supplements with placebo, no treatment, or usual care; 2) treatment and follow-up >=8 weeks; 3) participants over 18 years, with raised systolic blood pressure (SBP) >=140 mmHg or diastolic blood pressure (DBP) >=85 mmHg); 4) SBP and DBP reported at end of follow-up. We excluded trials where: participants were pregnant; received antihypertensive medication which changed during the study; or potassium supplementation was combined with other interventions. Two reviewers independently extracted data and assessed trial quality. Disagreements were resolved by discussion or a third reviewer. Random effects meta-analyses and sensitivity analyses were conducted. Six RCT's (n=483), with eight to 16 weeks follow-up, met our inclusion criteria. Meta-analysis of five trials (n=425) with adequate data indicated that potassium supplementation compared to control resulted in a large but statistically non-significant reductions in SBP (mean difference: -11.2, 95% CI: -25.2 to 2.7) and DBP (mean difference: -5.0, 95% CI: -12.5 to 2.4). The substantial heterogeneity between trials was not explained by potassium dose, quality of trials or baseline blood pressure. Excluding one trial in an African population with very high baseline blood pressure resulted in smaller overall reductions in blood pressure (SBP mean difference: -3.9, 95% CI: -8.6 to 0.8; DBP mean difference: -1.5, 95% CI: -6.2 to 3.1). Further sensitivity analysis restricted to two high quality trials (n=138) also found non-significant reductions in blood pressure (SBP mean difference: -7.1, 95% CI: -19.9 to 5.7; DBP mean difference: -5.5, 95% CI: -14.5 to 3.5). This systematic review found no statistically significant effect of potassium supplementation on blood pressure. Because of the small number of participants in the two high quality trials, the short duration of follow-up, and the unexplained heterogeneity between trials, the evidence about the effect of potassium supplementation on blood pressure is not conclusive. Further high quality RCTs of longer duration are required to clarify whether potassium supplementation can reduce blood pressure and improve health outcomes.

Validation of the Microlife BPA100 Plus device for self-home blood pressure measurement according to the International Protocol

Current guidelines recommend that only validated devices for blood pressure measurement should be used. This study presents the validation results of the Microlife BPA100 Plus monitor for self-home blood pressure measurement, according to the European Society of Hypertension International Protocol. Fifteen study participants were included in phase 1 and an additional 18 in phase 2 (total 33). Simultaneous blood pressure measurements were taken by two trained observers (Y tube connected mercury sphygmomanometers) four times, sequentially with three measurements taken using the tested device. Absolute differences between observer and device blood pressure were classified into three zones (within 5, 10 and 15 mmHg). The number of readings with a difference within 5 mmHg was calculated for each individual. In phase 1, the device produced 32, 42 and 43 measurements within 5, 10 and 15 mmHg, respectively, for systolic blood pressure and 31, 45 and 45 for diastolic blood pressure. In phase 2.1, the device produced 71, 87 and 96 measurements within 5, 10 and 15 mmHg, respectively, for systolic blood pressure, and 71, 98 and 99 measurements for diastolic blood pressure. In phase 2.2, 26 participants had at least two of their differences within 5 mmHg and three participants had no differences within 5 mmHg for systolic blood pressure, whereas for diastolic blood pressure 24 and three participants, respectively. Mean systolic blood pressure differences were -2.0+/-6.0 mmHg and diastolic blood pressure differences were -3.1+/-4.1 mmHg. The Microlife BPA100 Plus device for self-home blood pressure measurement comfortably passes the validation requirements of the International Protocol and therefore can be recommended for clinical use in the adult population.

The influence of the alpha-adducin G460W polymorphism and angiotensinogen M235T polymorphism on antihypertensive medication and blood pressure

Despite the availability of a variety of effective antihypertensive drugs, inadequate control of blood pressure is common in hypertensive patients. The aim of this study was investigate whether the alpha-adducin G460W polymorphism or angiotensinogen M235T polymorphism has an effect on the mean difference in blood pressure in subjects using antihypertensive drugs. Data from the Rotterdam Study, a population-based prospective cohort study in the Netherlands, was used. This study started in 1990 and included 7983 subjects of 55 years and older. Data from three examination rounds were used. Subjects were included when their blood pressure was elevated at 1 or more examinations and/or a diuretic, beta-blocker, calcium antagonist, or ACE inhibitor was used. A marginal generalized linear model was used to assess the drug-gene interaction. In total, 3025 hypertensives were included. No drug-gene interaction on blood pressure levels was found. The mean difference in systolic blood pressure (SBP) between subjects with the W-allele and GG genotype of the alpha-adducin gene was for diuretic users 1.25 mmHg (95% CI:-2.86 to 5.35), for beta-blockers 0.02 mmHg (95% CI:-3.39 to 3.42), for calcium antagonists -0.70 mmHg (95% CI:-5.61 to 4.21), and for ACE inhibitors -3.50 mmHg (95% CI:-9.02 to 2.02). The mean difference in SBP between subjects with the TT and MM genotype was for diuretic users -2.33 mmHg (95% CI:-8.32 to 3.66), for beta-blocker -0.06 mmHg (95% CI:-4.91 to 4.79), for calcium antagonist 0.59 mmHg (95% CI:-5.95 to 7.13), and for ACE inhibitor -2.33 mmHg (95% CI:-9.66 to 5.01). The G460W polymorphism and the M235T polymorphism did not modify the difference in blood pressure levels among subjects who used diuretics, beta-blockers, calcium antagonists, or ACE inhibitors.

Analysis of Recent Papers in Hypertension

Analysis of Recent Papers in Hypertension

Nephrolithiasis and Increased Blood Pressure Among Females With High Body Mass Index

We hypothesized that one reason for the heterogeneity in previously reported links between kidney stones and blood pressure (BP) was the differential effects of nephrolithiasis among subgroups of individuals. In particular, we hypothesized that the association between stone history and BP may vary with respect to sex and body size. Data from the Third National Health and Nutrition Examination Survey were used to estimate the association between history of stone disease and odds of prior diagnosis of hypertension and mean difference in systolic BP, diastolic BP, and pulse pressure. Nine hundred nineteen persons with a history of stones and 19,120 persons without stones were available for analysis. In women, it was estimated that stone formers (SFs) experienced a 69% increase in odds of self-reported hypertension (95% confidence interval [CI], 1.33 to 2.17; P < 0.001). No significant difference was found in men. The estimated difference in mean systolic and diastolic BP comparing SFs with non-SFs increased with body mass index in both sexes, but was more pronounced in women. Mean systolic BPs in women SFs in quintiles 4 and 5 of body mass index were 7.62 mm Hg (95% CI, 1.04 to 14.2; P = 0.024) and 4.36 mm Hg (95% CI, 0.30 to 8.42; P = 0.036) greater than those in similar women non-SFs, respectively. Our findings not only support the link between kidney stone disease and BP, but also suggest that overweight women SFs may be at significantly increased risk for hypertension.

Does nocturnal blood pressure fall in people of African and South Asian descent differ from that in European white populations? A systematic review and meta-analysis

To assess whether nocturnal blood pressure fall in people of African (Black) and South Asian descent differs from that of the European origin white populations (White). A systematic literature review was carried out using Medline 1966-2003 and Embase 1980-2003, and citations from references. The meta-analysis was performed using Cochrane review manager software (RevMan version 4.2; The Cochrane Collaboration, Oxford, UK). Seventeen studies were identified; 11 studies from the USA, one from the USA and Canada, and six studies from the United Kingdom. The mean percentage systolic blood pressure (SBP) nocturnal fall was below 10% (non-dipping) in 10 of 17 studies (59%) and the diastolic blood pressure (DBP) nocturnal fall was below 10% in four of 16 studies (25%) in Blacks compared with four of 17 studies (24%) in SBP and none in DBP nocturnal falls in Whites. Compared with Whites, Blacks had a significantly lower mean percentage nocturnal fall; the overall weighted mean difference in SBP was -3.07 (95% confidence interval, -3.81, -2.33; P < 0.00001) and in DBP was -2.98 (95% confidence interval, -3.97, -2.00; P < 0.00001). Two studies on South Asians showed a higher SBP but a similar mean DBP nocturnal fall compared with Whites. Smaller nocturnal blood pressure falls and a higher prevalence of non-dipping may contribute to the higher levels of hypertension complications seen in Black people. No such phenomenon was seen in South Asians but more research is needed to explore their higher stroke mortality.

Surgical management of coarctation of the aorta and associated intracardiac defect

To study the efficiency of surgical treatment on coarctation of the aorta and associated with heart defect. From 1994 to 2001, 45 patients with aortic coarctation and associated with heart defect underwent surgical repair. They were divided into two groups: single-stage repair group (26 cases) and two-stage repair group (19 cases). There was mild or severe pulmonary hypertension in 23 cases (with mean pulmonary artery pressure being 56 mm Hg). There were two incisions used in first-stage group (single midline incision in 21 cases and left-side combined midline incision in 5 cases). The mean course for the second operation was 105 days in second-stage group. Two patients died in each group. Twenty-four patients had not blood pressure difference between arm and leg after operation. The mean systolic blood pressure difference was less than 10 mmHg in 10 patients. Mean period of follow-up was 28.6 months. No patients died and had re-coarctation. The operative results showed no difference between single-stage and two-stage repair in surgical correction of aortic coarctation associated intracardiac defect. The left-side combined midline incision in single-stage operation was an effective and safe technique.

Evidence for elevated pulse pressure in patients on chronic hemodialysis: A case-control study

Few analyses have compared pulse pressure (PP) values in hemodialysis patients with healthy individuals, and they have provided only limited data. We retrospectively examined PP in a large cohort of hemodialysis patients and healthy control subjects. The relationships of systolic blood pressure (SBP), diastolic blood pressure (DBP), and PP to mean arterial pressure (MAP) levels were investigated in 234 chronic hemodialysis patients and in 682 control subjects matched for age, sex, diabetes mellitus, and body mass index. In both control and patients, PP was positively correlated with MAP, and the two regression lines were parallel (beta of control subjects = 0.52; beta of hemodialysis patients = 0.57, P = 0.48). According to the regression line, at any MAP level, the PP in hemodialysis patients was significantly higher than that in control subjects: the mean PP difference between control and patients was 19.2 mm Hg (95% CI, 17.2 to 21.1 mm Hg, P < 0.0001). When the relationships between MAP and SBP and that between MAP and DBP were analyzed, the regression lines were also parallel. However, at any MAP level, SBP was higher and DBP was lower in hemodialysis patients than control subjects; the mean SBP difference was 12.8 mm Hg (95% CI, 11.5 to 14.1 mm Hg, P < 0.0001) and mean DBP difference was 6.4 mm Hg (95% CI, 5.7 to 7.0 mm Hg, P < 0.0001). At any MAP level, hemodialysis patients had a higher SBP, lower DBP, and higher PP values than those control subjects with a normal renal function who were matched for age, sex, diabetes mellitus, and body mass index. Further study is needed to determine whether preventing or reducing an elevated PP improves the prognosis for hemodialysis patients.

Socio-economic status and blood pressure: an overview analysis.

Mortality rates from hypertension related diseases such as coronary heart disease, hypertensive heart disease, stroke and end stage renal disease show an inverse association with socio-economic status (SES). To review the published literature in order to assess whether (i) there is an association between SES and blood pressure (BP), and if so whether this is explained by (ii) SES differences in treatment rates, or (iii) SES differences in established risk factors for hypertension, or (iv) psycho-social factors associated with SES. A narrative systematic review of published articles identified from a MEDLINE search from 1966-1996 and manual searching of the retrieved articles' bibliographies. Lower SES was associated with higher mean BPs in almost all studies in developed countries. This inverse gradient was both stronger and more consistently found in women than in men. The magnitude of the association varied but generally was quite small, with age adjusted mean systolic BP differences of about 2-3 mm Hg between the highest and lowest SES groups. The finding of an SES gradient in BP, despite adjusting for treatment in some studies and the lack of consistent SES differences in hypertension treatment rates, makes differential treatment an unlikely explanation for the SES gradient in BP. A substantial part of the SES gradient was accounted for by the SES gradient in body mass index. Alcohol consumption across SES groups accounted for part of the association in men though few studies examined this issue specifically. In contrast, in undeveloped or developing countries a direct association between SES and BP has often been found which may reflect a higher prevalence of obesity, and higher salt and alcohol intakes among those of higher SES. The SES differences in BP were not detectable in most studies in children. There is little evidence that adverse psycho-social factors associated with low SES cause chronic elevations in BP. A major challenge in reducing the SES gradient in BP is to understand and prevent the SES differences in obesity, which are particularly large in women. Future research should be directed to this question.

Sugar-induced hypertension in Fischer 344 and F1-hybrid rats (F344/BN) at different ages

Epidemiological evidence suggests that some nutrients, like sodium and potassium, participate in age-related hypertension. A role for refined carbohydrates (CHO), principally sugar, in blood pressure regulation is not generally recognized. This may be unfortunate, since modern lifestyle is associated with large amounts of dietary refined CHO. We examined the effect of a high sugar diet on systolic blood pressure (SBP) in Fischer 344 rats (F344) and the F1-hybrid of this strain (F344/BN). These genotypes have been used to develop experimental models for studies on different aspects of aging. Age-dependent hypertension has not been reported in either strain. In fact, insensitivity to salt-induced hypertension has been found in F344 rats. Upon arrival at our laboratory, the mean difference in SBP between the youngest (4 months) and oldest (18 months) F344 and F1-hybrid rats was 10 mm Hg, the highest mean SBP was 123 mm Hg. These values remained relatively constant over the next month when both strains consumed a low sugar diet. Differently, a steady increase in SBP occurred in both strains when rats of all ages were fed a diet high in sucrose content, mean SBP increasing to over 170 mm Hg at termination of study. Older rats proved more sensitive initially to sugar-induced SBP elevations. Associated with rising SBP was evidence of Na retention. We conclude that a diet containing excess sugar can create a gradual elevation of SBP into a hypertensive range with aging of F344 and F1-hybrid rats. This contrasts with previous findings.