Net Reduction In Blood Pressure Research Articles

Net Blood Pressure Reduction Following 9 Months of Lifestyle and High-Intensity Interval Training Intervention in Individuals With Abdominal Obesity.

The authors aimed to study the impact of a combined 9-month lifestyle program (Mediterranean diet nutritional counselling, and high-intensity interval training twice a week) on blood pressure (BP) in individuals with abdominal obesity, taking into account the regression-to-the-mean phenomena. A total of 115 participants (53±9 years; 84 women; waist circumference [WC]: 111±13 cm; systolic/diastolic BP [SBP/DBP]: 133±13/82±8 mm Hg; 13% diabetics; 12% smokers; and 30% taking antihypertensive therapy) were retrospectively analyzed before and after the program. After 9 months, we observed an improvement in weight (-5.2±5.6 kg) and WC (-6.3±6.0 cm), and an average SBP/DBP net decrease of -5.1±13.7/-2.8±8.7 mm Hg. These changes were not uniform: 67 participants (58%) decreased their SBP by 2 mm Hg or more. The characteristics of responders included a higher baseline BP than nonresponders (SBP/DBP: 137.2±13.7/83.1±7.3 mm Hg vs 127.0±10.3/80.0±7.3 mm Hg, P<.05) and a higher proportion of participants with a baseline BP ≥130/85 mm Hg (81% vs 52%, P=.001) or with the metabolic syndrome (75% vs 54%, P=.02).

A systematic review and meta-analysis of candesartan and losartan in the management of essential hypertension

Candesartan is a relatively novel antihypertensive agent of the angiotensin receptor blocker (ARB). Several clinical trials have compared candesartan with losartan in the management of essential hypertension. However, systematic assessment of efficacy and safety between candesartan and losartan is still lacking. We reviewed randomised controlled trials (RCTs) comparing candesartan with losartan for net reduction in blood pressure from baseline, response and control rates, and incidences of common and serious adverse events.Weighted mean differences (WMD), and relative risk (RR) with 95% confidence intervals (CI) were calculated for continuous and dichotomous data, respectively. A total of 12 RCTs with 3644 patients were included in this meta-analysis. When comparing the efficacy of candesartan and losartan in reducing systolic blood pressure (SBP) and diastolic blood pressure (DBP) at the end of the follow-up period, results with candesartan were superior to losartan in the reduction SBP and DBP (WMD, -2.97; 95% CI, -4.18 - -1.77; p < 0.001; WMD, -1.76; 95% CI, -2.57 - -0.96; p < 0.001; respectively). Candesartan had better response and control rates than losartan. (RR, 1.12; 95% CI, 1.06-1.18; p < 0.01; RR, 1.26; 95% CI, 1.06-1.50; p = 0.008). Reported common adverse events for the two agents were not significantly different (RR, 0.98; 95% CI, 0.86-1.12; p = 0.78). The incidence of serious adverse events for candesartan was lower than for losartan (RR, 0.48; 95% CI, 0.25-0.92; p = 0.03). The net reduction of DBP showed negative correlation with baseline DBP in both candesartan and losartan groups (regression coefficient -1.81, p = 0.03 and regression coefficient -1.56, p = 0.02, respectively). Candesartan is superior to losartan in reducing blood pressure. Candesartan also causes fewer serious adverse events than losartan.

Interventions used to improve control of blood pressure in patients with hypertension

Patients with high blood pressure (hypertension) in the community frequently fail to meet treatment goals - a condition labelled as "uncontrolled" hypertension. The optimal way to organize and deliver care to hypertensive patients has not been clearly identified. To determine the effectiveness of interventions to improve control of blood pressure in patients with hypertension. To evaluate the effectiveness of reminders on improving the follow-up of patients with hypertension. All-language search of all articles (any year) in the Cochrane Controlled Trials Register (CCTR) and Medline; and Embase from January 1980. Randomized controlled trials (RCTs) of patients with hypertension that evaluated the following interventions: (1) self-monitoring (2) educational interventions directed to the patient (3) educational interventions directed to the health professional (4) health professional (nurse or pharmacist) led care (5) organisational interventions that aimed to improve the delivery of care (6) appointment reminder systemsOutcomes assessed were: (1) mean systolic and diastolic blood pressure (2) control of blood pressure (3) proportion of patients followed up at clinic Two authors extracted data independently and in duplicate and assessed each study according to the criteria outlined by the Cochrane Handbook. 72 RCTs met our inclusion criteria. The methodological quality of included studies varied. An organized system of regular review allied to vigorous antihypertensive drug therapy was shown to reduce systolic blood pressure (weighted mean difference (WMD) -8.0 mmHg, 95% CI: -8.8 to -7.2 mmHg) and diastolic blood pressure (WMD -4.3 mmHg, 95% CI: -4.7 to -3.9 mmHg) for three strata of entry blood pressure, and all-cause mortality at five years follow-up (6.4% versus 7.8%, difference 1.4%) in a single large RCT- the Hypertension Detection and Follow-Up study. Other interventions had variable effects. Self-monitoring was associated with moderate net reduction in systolic blood pressure (WMD -2.5 mmHg, 95% CI: -3.7 to -1.3 mmHg) and diastolic blood pressure (WMD -1.8 mmHg, 95% CI: -2.4 to -1.2 mmHg). RCTs of educational interventions directed at patients or health professionals were heterogeneous but appeared unlikely to be associated with large net reductions in blood pressure by themselves. Nurse or pharmacist led care may be a promising way forward, with the majority of RCTs being associated with improved blood pressure control and mean SBP and DBP but these interventions require further evaluation. Appointment reminder systems also require further evaluation due to heterogeneity and small trial numbers, but the majority of trials increased the proportion of individuals who attended for follow-up (odds ratio 0.41, 95% CI 0.32 to 0.51) and in two small trials also led to improved blood pressure control, odds ratio favouring intervention 0.54 (95% CI 0.41 to 0.73). Family practices and community-based clinics need to have an organized system of regular follow-up and review of their hypertensive patients. Antihypertensive drug therapy should be implemented by means of a vigorous stepped care approach when patients do not reach target blood pressure levels. Self-monitoring and appointment reminders may be useful adjuncts to the above strategies to improve blood pressure control but require further evaluation.

Relaxation therapies for the management of primary hypertension in adults: a Cochrane review

The objective of this review was to evaluate the effectiveness of relaxation to lower high blood pressure. We searched electronic bibliographic databases and grey literature to identify randomized controlled trials comparing relaxation therapies with no active treatment or sham therapy, enrolling adult participants with raised systolic blood pressure (SBP) > or = 140 mm Hg or diastolic blood pressure (DBP) > or = 85 mm Hg and follow-up > or = 8 weeks. Twenty-five trials with up to 5 years follow-up, assessing 1198 participants, met our inclusion criteria and were meta-analysed. Overall, relaxation resulted in small, statistically significant reductions in SBP (mean difference: -5.5 mm Hg, 95% CI: -8.2 to -2.8) and DBP (mean difference: -3.5 mm Hg, 95% CI: -5.3 to -1.6) compared to the control. Substantial heterogeneity between trials (I2 > 70%) was not explained by duration of follow-up, type of control, type of relaxation therapy or baseline blood pressure. The 9 trials that reported blinding of outcome assessors found a non-significant net reduction in blood pressure (SBP mean difference: -3.2 mm Hg, 95% CI: -7.7 to 1.4) associated with relaxation, as did the 15 trials comparing relaxation with sham therapy (SBP mean difference: -3.5 mm Hg, 95% CI: -7.1 to 0.2). Adequate randomization was confirmed in only seven trials and concealment of allocation in only one. In view of the poor quality of the included trials and unexplained variation between trials, the evidence in favour of a 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.

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.

Obesity and type 2 diabetes mellitus

Obesity and type 2 diabetes mellitus

Effect of Nocturnal Nasal Continuous Positive Airway Pressure on Blood Pressure in Obstructive Sleep Apnea

Obstructive sleep apnea (OSA) is a very common risk factor for hypertension, and continuous positive airway pressure (CPAP) has been widely used to treat OSA. We conducted a meta-analysis of randomized, controlled trials to evaluate the effects of CPAP on blood pressure, reported as either a primary or secondary end point, among patients with OSA. Studies were retrieved by searching Medline (January 1980 to July 2006), the Cochrane Database of Systematic Reviews, conference abstracts, and bibliographies of review and original articles. From 255 relevant reports, 16 randomized clinical trials were selected that compared CPAP to control among participants with OSA, had a minimum treatment duration of 2 weeks, and reported blood pressure changes during the intervention or control period. Data on sample size, participant characteristics, study design, intervention methods, duration, and treatment results were independently abstracted by 2 investigators using a standardized protocol. Data from 16 trials representing 818 participants were examined using a random-effects model. Mean net change in systolic blood pressure for those treated with CPAP compared with control was -2.46 mm Hg (95% CI: -4.31 to -0.62); mean net change in diastolic blood pressure was -1.83 mm Hg (95% CI: -3.05 to -0.61); and mean net change in mean arterial pressure was -2.22 mm Hg (95% CI: -4.38 to -0.05). Net reductions in blood pressure were not statistically different between daytime and nighttime. These results indicate that CPAP decreases blood pressure among those with OSA and may help prevent hypertension.

Effect of exercise on blood pressure control in hypertensive patients

Several large epidemiological studies have reported an inverse relationship between blood pressure and physical activity. However, longitudinal intervention studies are more appropriate for assessing the effects of physical activity. We performed meta-analyses of randomized controlled trials involving dynamic aerobic endurance training or resistance training. The meta-analysis on endurance training involved 72 trials and 105 study groups. After weighting for the number of trained participants, training induced significant net reductions in resting and daytime ambulatory blood pressure of, respectively, 3.0/2.4 mmHg (P<0.001) and 3.3/3.5 mmHg (P<0.01). The reduction in resting blood pressure was more pronounced in the 30 hypertensive study groups (-6.9/-4.9) than in the others (-1.9/-1.6; P<0.001 for all). Systemic vascular resistance decreased by 7.1% (P<0.05), plasma norepinephrine by 29% (P<0.001), and plasma renin activity by 20% (P<0.05). Body weight decreased by 1.2 kg (P<0.001), waist circumference by 2.8 cm (P<0.001), percentage body fat by 1.4% (P<0.001) and the homeostasis model assessment index of insulin resistance by 0.31 units (P<0.01); high-density lipoprotein cholesterol increased by 0.032 mmol/l (P<0.05). Resistance training has been less well studied. A meta-analysis of nine randomized controlled trials (12 study groups) on mostly dynamic resistance training revealed a weighted net reduction in blood pressure of 3.2 (P=0.10)/3.5 (P<0.01) mmHg associated with exercise. Endurance training decreases blood pressure through a reduction in systemic vascular resistance, in which the sympathetic nervous system and the renin-angiotensin system appear to be involved, and favourably affects concomitant cardiovascular risk factors. The few available data suggest that resistance training can reduce blood pressure. Exercise is a cornerstone therapy for the prevention, treatment and control of hypertension.

Behavioral Treatment of Hypertension

Behavioral Treatment of Hypertension

Blood pressure and the prevention of stroke

RELATIONSHIP BETWEEN BLOOD PRESSURE AND STROKE: Data from prospective observational studies indicate that usual levels of blood pressure are directly and continuously related to the risk of initial stroke. A prolonged difference in usual blood pressure levels of just 9/5 mmHg is associated with approximately a one-third difference in stroke risk, with similar proportional effects in hypertensives and normotensives. Recent data from studies of individuals with a history of cerebrovascular disease indicate a similar association between blood pressure and the risk of recurrent stroke. EFFECTS OF TREATMENT ON STROKE: The results of randomized trials of blood pressure-lowering drugs in hypertensive patients suggest that much or all of the long-term potential stroke avoidance associated with prolonged blood pressure differences can be achieved within just a few years of beginning treatment. Overall, in 17 randomized trials of antihypertensive treatment a net blood pressure reduction of 10-12 mmHg systolic and 5-6 mmHg diastolic conferred a reduction in stroke incidence of 38% (SD 4), with similar reductions in fatal and non-fatal stroke. Because the proportional effects of treatment were similar in higher and lower risk patient groups, the absolute effects of treatment on stroke varied in direct proportion to the background risk of stroke. The greatest potential benefits were observed among those with a history of cerebrovascular disease; however, the results of the trials conducted in patients with a history of stroke or transient ischaemic attack, although promising, were not definitive. New trials are required to determine more reliably the effects of blood pressure lowering in patients with cerebrovascular disease.

The Hypertension Prevention Trial: three-year effects of dietary changes on blood pressure. Hypertension Prevention Trial Research Group

A total of 841 healthy men and women aged 25 to 49 years, with diastolic blood pressures of 78 to 89 mm Hg, were randomly assigned to a control treatment group (no dietary counseling) or to one of four dietary counseling treatment groups (reduced calories, reduced sodium, reduced sodium and calories, or reduced sodium and increased potassium). Participants were followed for a 3-year period to assess the effect of dietary changes on blood pressure. After 6 months, counseling had resulted in a net (of control) mean overnight urinary sodium reduction of 13%, a potassium increase of 8%, and a decrease in mean body weight of 7%. At 3 years, the sodium and weight reductions were 10% and 4%, respectively; the potassium change was nil. All four dietary counseling treatment groups had lower mean blood pressures than the control group. The largest net reduction in blood pressure occurred in the calorie group: diastolic pressure was 2.8 mm Hg and 1.8 mm Hg and systolic pressure, 5.1 mm Hg and 2.4 mm Hg at 6 months and 3 years, respectively. All four dietary counseling treatment groups experienced fewer hypertensive events; significantly fewer occurred in the sodium groups. The beneficial effects on blood pressure achieved in this trial have implications for the prevention of cardiovascular disease through dietary reduction of calories and sodium.

Blood pressure reductions: Correcting for regression to the mean

Reductions in high blood pressure (BP) from participating in screening and treatment programs are often assessed by comparing BP measurements before and after participation. The interpretation of such changes in measured blood pressure is confounded by the tendency of high pressures to decline as a result of a statistical artifact—regression to the mean. The problem arises whenever baseline measurements are used both for selection of participants and for comparisons with pressures obtained later. We developed a statistical model which predicts the average decline due to regression for participants in a screening or treatment program. This regression effect must be subtracted from the observed reduction in BP (the difference between baseline and later measurements) to obtain the average net reduction in BP from the program. The regression effect is estimated as the product of two factors. The first factor is the proportion of the variance in the baseline (preprogram) measurement due to measurement error and the short-term variation (e.g., 0.24 for two replications averaged). The second factor is the difference between the mean baseline pressure of full participants and that of the underlying population of potential participants. The model was first illustrated with successive BP measurements from community screening programs, where the “program” was only remeasurement. The mean observed decline in diastolic BP between screens for 145 persons with elevated baseline BP was 7 mm Hg. After adjustment for regression to the mean, the net decline between screens was estimated to be 2 mm Hg. This decline is apparently due to the pressor effect, or stress of screening, and agrees with findings from other studies. Next the model was applied to the treatment phase of the Hypertension Detection and Follow-up Program. Overall, net reductions predicted by the model agree with those from independent measurements to within 0.1 mm Hg. The findings indicate the one can compute net reductions in BP from before-and-after comparisons in screening and treatment programs with reasonable accuracy, and these net reductions are generally much smaller than the crude BP declines.

The influence of age on reactive hyperaemia in the human calf: a study with strain gauge plethysmography.

Postischaemic reactive hyperaemia in the calf was investigated by strain gauge plethysmography in four groups of ten subjects. The mean age of the different groups was 6, 13, 24 and 57 years respectively. Basal calf flow, repayment and recovery time in the 6-year-old children were greater than in the other groups, which may be related to a higher metabolic rate in young children. Maximal flow in the four groups was not significantly different, which indicates that the arteriolar response to circulatory arrest is not altered by increasing age. The cause of delay in maximal flow in the group of 6-year-olds is not clearly understood. Basal and postischaemic lowest peripheral resistance increased with age, which is probably caused by changes of the arterioles due to ageing and possibly inactivity. The fall in peripheral resistance induced by 3 min of ischaemia was positively correlated with mean blood pressure. This may be due to a greater net reduction in blood pressure during ischaemia, which brobably elicits a stronger myogenic response of the vessel wall. It is concluded that in clinical use of the reactive hyperaemia test in the calf, the influence of age is of minor importance, whereas postischaemic peripheral resistance is a more accurate measure of vasocilation for comparison of subjects with different blood pressure.