Importance of salt in determining blood pressure in children: meta-analysis of controlled trials

To assess the effect of reducing salt intake on blood pressure in children, we carried out a meta-analysis of controlled trials. Trials were included if participants were children (< or = 18 years), and duration of salt reduction must have been for > or = 2 weeks. Mean effect size was calculated using a fixed-effect model, because there was no significant heterogeneity. Ten trials of children and adolescents with 966 participants were included (median age: 13 years; range: 8 to 16 years; median duration: 4 weeks; range: 2 weeks to 3 years). Salt intake was reduced by 42% (interquartile range [IQR]: 7% to 58%). There were significant reductions in blood pressure: systolic: -1.17 mm Hg (95% CI: -1.78 to -0.56 mm Hg; P<0.001); diastolic: -1.29 mm Hg (95% CI: -1.94 to -0.65 mm Hg; P<0.0001). Three trials of infants with 551 participants were included (median duration: 20 weeks; range: 8 weeks to 6 months). Salt intake was reduced by 54% (IQR: 51% to 79%). There was a significant reduction in systolic blood pressure: -2.47 mm Hg (95% CI: -4.00 to -0.94 mm Hg; P<0.01). This is the first meta-analysis of salt reduction in children, and it demonstrates that a modest reduction in salt intake causes immediate falls in blood pressure and, if continued, may well lessen the subsequent rise in blood pressure with age. This would result in major reductions in cardiovascular disease. These results in conjunction with other evidence provide strong support for a reduction in salt intake in children.     

The effect of magnesium supplementation on blood pressure: a meta-analysis of randomized clinical trials

BACKGROUND: An increased intake of magnesium might lower blood pressure (BP), yet evidence from clinical trials is inconsistent, perhaps as a result of small sample size or heterogeneity in study design. METHODS: We performed a meta-analysis of randomized trials that tested the effects of magnesium supplementation on BP. Twenty trials meeting the inclusion criteria were identified. Random effects models and meta-regression methods were used to pool study results and to determine the dose-response relationship of magnesium to BP. RESULTS: The 20 studies included 14 of hypertensive and 6 of normotensive persons totaling 1220 participants. The doses of magnesium ranged from 10 to 40 mmol/day (median, 15.4 mmol/day). Magnesium supplementation resulted in only a small overall reduction in BP. The pooled net estimates of BP change (95% confidence interval [CI]) were -0.6 (-2.2 to 1.0) mm Hg for systolic BP and -0.8 (-1.9 to 0.4) mm Hg for diastolic BP. However, there was an apparent dose-dependent effect of magnesium, with reductions of 4.3 mm Hg systolic BP (95% CI 6.3 to 2.2; P < .001) and of 2.3 mm Hg diastolic BP (95% CI 4.9 to 0.0; P = .09) for each 10 mmol/day increase in magnesium dose. CONCLUSIONS: Our meta-analysis detected dose-dependent BP reductions from magnesium supplementation. However, adequately powered trials with sufficiently high doses of magnesium supplements need to be performed to confirm this relationship.     

Blood pressure response to transcendental meditation: a meta-analysis

BACKGROUND: Prior clinical trials suggest that the Transcendental Meditation technique may decrease blood pressure of normotensive and hypertensive individuals but study-quality issues have been raised. This study was designed to assess effects of Transcendental Meditation on blood pressure using objective quality assessments and meta-analyses. METHODS: PubMed and Cochrane databases through December 2006 and collected publications on Transcendental Meditation were searched. Randomized, controlled trials comparing blood pressure responses to the Transcendental Meditation technique with a control group were evaluated. Primary outcome measures were changes in systolic and diastolic blood pressure after practicing Transcendental Meditation or following control procedures. A specific rating system (0-20 points) was used to evaluate studies and random-effects models were used for meta-analyses. RESULTS: Nine randomized, controlled trials met eligibility criteria. Study-quality scores ranged from low (score, 7) to high (16) with three studies of high quality (15 or 16) and three of acceptable quality (11 or 12). The random-effects meta-analysis model for systolic and diastolic blood pressure, respectively, indicated that Transcendental Meditation, compared to control, was associated with the following changes: -4.7 mm Hg (95% confidence interval (CI), -7.4 to -1.9 mm Hg) and -3.2 mm Hg (95% CI, -5.4 to -1.3 mm Hg). Subgroup analyses of hypertensive groups and high-quality studies showed similar reductions. CONCLUSIONS: The regular practice of Transcendental Meditation may have the potential to reduce systolic and diastolic blood pressure by approximately 4.7 and 3.2 mm Hg, respectively. These are clinically meaningful changes.     

Balloon angioplasty or medical therapy for hypertensive patients with atherosclerotic renal artery stenosis? A meta-analysis of randomized controlled trials

PURPOSE: The optimal treatment for hypertensive patients with atherosclerotic renal artery stenosis is controversial. We performed a meta-analysis comparing the effects of balloon angioplasty and medical therapy in these patients. METHODS: We searched MEDLINE, EMBASE, the Science Citation Index, the Cochrane Controlled Trials Registry, and reference lists. Authors of published trials were contacted. RESULTS: We identified three trials involving a total of 210 patients with moderate-to-severe (> or = 50%) unilateral or bilateral atherosclerotic renal artery stenosis and poorly controlled hypertension who were followed for at least 3 months after intervention. Balloon angioplasty was significantly more effective in reducing blood pressure than was medical therapy; the weighted mean difference between the two treatments was -7 mm Hg (95% confidence interval [CI]: -12 to -1 mm Hg) for systolic blood pressure and -3 mm Hg (95% CI: -6 to -1 mm Hg) for diastolic blood pressure. There was no consistent difference in changes in renal function. Patients treated with balloon angioplasty were more likely to have patent renal arteries after 12 months (52% vs. 19%; odds ratio [OR] = 4.2; 95% CI: 1.8 to 9.8), used fewer antihypertensive medications, and appeared to have fewer major cardiovascular and renovascular complications (OR = 0.27; 95% CI: 0.06 to 1.23; P = 0.09). CONCLUSION: Balloon angioplasty has a modest but significant effect on blood pressure and should be considered for patients with atherosclerotic renal artery stenosis and poorly controlled hypertension. There is no evidence supporting its use in improving or preserving renal function, although none of the trials were designed to address this issue.     

Effect of cocoa and tea intake on blood pressure: a meta-analysis

BACKGROUND: Epidemiological evidence suggests blood pressure-lowering effects of cocoa and tea. We undertook a meta-analysis of randomized controlled trials to determine changes in systolic and diastolic blood pressure due to the intake of cocoa products or black and green tea. METHODS: MEDLINE, EMBASE, SCOPUS, Science Citation Index, and the Cochrane Controlled Trials Register were searched from 1966 until October 2006 for studies in parallel group or crossover design involving 10 or more adults in whom blood pressure was assessed before and after receiving cocoa products or black or green tea for at least 7 days. RESULTS: Five randomized controlled studies of cocoa administration involving a total of 173 subjects with a median duration of 2 weeks were included. After the cocoa diets, the pooled mean systolic and diastolic blood pressure were -4.7 mm Hg (95% confidence interval [CI], -7.6 to -1.8 mm Hg; P = .002) and -2.8 mm Hg (95% CI, -4.8 to -0.8 mm Hg; P = .006) lower, respectively, compared with the cocoa-free controls. Five studies of tea consumption involving a total of 343 subjects with a median duration of 4 weeks were selected. The tea intake had no significant effects on blood pressure. The estimated pooled changes were 0.4 mm Hg (95% CI, -1.3 to 2.2 mm Hg; P = .63) in systolic and -0.6 mm Hg (95% CI, -1.5 to 0.4 mm Hg; P = .38) in diastolic blood pressure compared with controls. CONCLUSION: Current randomized dietary studies indicate that consumption of foods rich in cocoa may reduce blood pressure, while tea intake appears to have no effect.     

Role of home blood pressure monitoring in overcoming therapeutic inertia and improving hypertension control: a systematic review and meta-analysis

Hypertension remains the most common modifiable cardiovascular risk factor, yet hypertension control rates remain dismal. Home blood pressure (BP) monitoring has the potential to improve hypertension control. The purpose of this review was to quantify both the magnitude and mechanisms of benefit of home BP monitoring on BP reduction. Using a structured review, studies were selected if they reported either changes in BP or percentage of participants achieving a pre-established BP goal between randomized groups using home-based and office-based BP measurements. A random-effects model was used to estimate the magnitude of benefit and relative risk. The search yielded 37 randomized controlled trials with 9446 participants that contributed data for this meta-analysis. Compared with clinic-based measurements (control group), systolic BP improved with home-based BP monitoring (-2.63 mm Hg; 95% CI, -4.24, -1.02); diastolic BP also showed improvement (-1.68 mm Hg; 95% CI, -2.58, -0.79). Reductions in home BP monitoring-based therapy were greater when telemonitoring was used. Home BP monitoring led to more frequent antihypertensive medication reductions (relative risk, 2.02 [95% CI, 1.32 to 3.11]) and was associated with less therapeutic inertia defined as unchanged medication despite elevated BP (relative risk for unchanged medication, 0.82 [95% CI, 0.68 to 0.99]). Compared with clinic BP monitoring alone, home BP monitoring has the potential to overcome therapeutic inertia and lead to a small but significant reduction in systolic and diastolic BP. Hypertension control with home BP monitoring can be enhanced further when accompanied by plans to monitor and treat elevated BP such as through telemonitoring.     

Progression is accelerated from prehypertension to hypertension in blacks

Prehypertension is a major risk factor for hypertension. Blacks have more prevalent and severe hypertension than whites, but it is unknown whether progression from prehypertension is accelerated in blacks. We examined this question in a prospective cohort study of 18 865 nonhypertensive persons (5733 black [30.4%] and 13 132 white [69.6%]) aged 18 to 85 years. Electronic health record data were obtained from 197 community-based outpatient clinics in the Southeast United States. Days elapsing from study entry to hypertension diagnosis, mainly blood pressure ≥140 mm Hg systolic and/or ≥90 mm Hg diastolic on 2 consecutive visits established conversion time within a maximum observation period of 2550 days. Cox regression modeling was used to examine conversion to hypertension as a function of race, while controlling for age, sex, baseline systolic and diastolic blood pressures, body mass index, diabetes mellitus, and chronic kidney disease. The covariable adjusted median conversion time when 50% became hypertensive was 365 days earlier for blacks than whites (626 versus 991 days; P<0.001). Among covariables, baseline systolic blood pressure 130 to 139 mm Hg (hazard ratio: 1.77 [95% CI: 1.69 to 1.86]) and 120 to 129 mm Hg (hazard ratio: 1.52 [95% CI: 1.44 to 1.60]), as well as age ≥75 years (hazard ratio: 1.40 [95% CI: 1.29 to 1.51]) and 55 to 74 years (hazard ratio: 1.29 [95% CI: 1.23 to 1.35]) were the strongest predictors of hypertension. Additional predictors included age 35 to 54 years, diastolic blood pressure 80 to 89 mm Hg, overweight and obesity, and diabetes mellitus (all P<0.001). Conversion from prehypertension to hypertension is accelerated in blacks, which suggests that effective interventions in prehypertension could reduce racial disparities in prevalent hypertension.     

Association between blood pressure and serum thyroid-stimulating hormone concentration within the reference range: a population-based study

CONTEXT: The association between thyroid function and blood pressure is insufficiently studied. OBJECTIVE: The objective of the investigation was to study the association between TSH within the reference range and blood pressure. DESIGN AND SETTING: This was a cross-sectional, population-based study. SUBJECTS: A total of 30,728 individuals without previously known thyroid disease were studied. MAIN OUTCOME MEASURES: The main outcome measures were mean systolic and diastolic blood pressure and pulse pressure and odds ratio for hypertension (>140/90 mm Hg or current or previous use of antihypertensive medication), according to categories of TSH. RESULTS: Within the reference range of TSH (0.50-3.5 mU/liter), there was a linear increase in blood pressure with increasing TSH. The average increase in systolic blood pressure was 2.0 mm Hg [95% confidence interval (CI) 1.4-2.6 mm Hg] per milliunit per liter increase in TSH among men, and 1.8 mm Hg (95% CI 1.4-2.3 mm Hg) in women. The corresponding increase in diastolic blood pressure was 1.6 mm Hg (95% CI 1.2-2.0 mm Hg) in men and 1.1 mm Hg (95% CI 0.8-1.3 mm Hg) in women. Comparing TSH of 3.0-3.5 mU/liter (upper part of the reference) with TSH of 0.50-0.99 mU/liter (lower part of the reference), the odds ratio for hypertension was 1.98 (95% CI 1.56-2.53) in men and 1.23 (95% CI 1.04-1.46) in women. CONCLUSION: Within the reference range of TSH, we found a linear positive association between TSH and systolic and diastolic blood pressure that may have long-term implications for cardiovascular health.     

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.     

Long-term effects of weight-reducing interventions in hypertensive patients: systematic review and meta-analysis

Weight loss is recommended in all major guidelines for antihypertensive therapy. We searched for randomized controlled trials investigating the effects of weight-reducing diets, pharmacologic substances, and invasive interventions for weight reduction on patient-relevant end points and blood pressure (BP) in patients with essential hypertension. No information on the effects on patient-relevant end points was available. Patients assigned to weight loss diets, orlistat, or sibutramine reduced their body weight more effectively than did patients in the usual care/placebo groups. Reduction of BP was higher in patients treated with weight loss diets (systolic BP [SBP]: weighted mean difference [WMD], -6.3 mm Hg; diastolic BP [DBP]: WMD, -3.4 mm Hg) or orlistat (SBP: WMD, -2.5 mm Hg; DBP: WMD, -2.0 mm Hg). Systolic BP increased with sibutramine treatment (WMD, 3.2 mm Hg). In patients with essential hypertension, therapy with a weight loss diet or orlistat resulted in reductions in body weight and BP. Although sibutramine treatment reduced body weight, it did not lower BP.     

Aerobic exercise and resting blood pressure: a meta-analytic review of randomized, controlled trials

In this study the authors used the meta-analytic approach to examine the effects of aerobic exercise on resting systolic and diastolic blood pressure in adults. Forty-seven clinical trials representing a total of 72 effect sizes in 2543 subjects (1653 exercise, 890 control) met the criteria for inclusion. Statistically significant exercise-minus-control decreases were found for changes in resting systolic and diastolic blood pressure in both hypertensive (systolic, −6 mm Hg, 95% CI, −8 to −3; diastolic, −5 mm Hg, 95% CI, −7 to −3) and normotensive (systolic, −2 mm Hg, 95% CI, −3 to −1; diastolic, −1 mm Hg, 95% CI, −2 to −1) groups. The differences between groups were statistically significant (systolic, p =0.008; diastolic, p =0.000). Relative decreases were approximately 4% (systolic) and 5% (diastolic) in hypertensives, and 2% (systolic) and 1% (diastolic) in normotensives. It was concluded that aerobic exercise reduces resting systolic and diastolic blood pressure in adults.     

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.     

Exercise-based rehabilitation for patients with coronary heart disease: systematic review and meta-analysis of randomized controlled trials

PURPOSE: To review the effectiveness of exercise-based cardiac rehabilitation in patients with coronary heart disease. METHODS: A systematic review and meta-analysis of randomized controlled trials was undertaken. Databases such as MEDLINE, EMBASE, and the Cochrane Library were searched up to March 2003. Trials with 6 or more months of follow-up were included if they assessed the effects of exercise training alone or in combination with psychological or educational interventions. RESULTS: We included 48 trials with a total of 8940 patients. Compared with usual care, cardiac rehabilitation was associated with reduced all-cause mortality (odds ratio [OR] = 0.80; 95% confidence interval [CI]: 0.68 to 0.93) and cardiac mortality (OR = 0.74; 95% CI: 0.61 to 0.96); greater reductions in total cholesterol level (weighted mean difference, -0.37 mmol/L [-14.3 mg/dL]; 95% CI: -0.63 to -0.11 mmol/L [-24.3 to -4.2 mg/dL]), triglyceride level (weighted mean difference, -0.23 mmol/L [-20.4 mg/dL]; 95% CI: -0.39 to -0.07 mmol/L [-34.5 to -6.2 mg/dL]), and systolic blood pressure (weighted mean difference, -3.2 mm Hg; 95% CI: -5.4 to -0.9 mm Hg); and lower rates of self-reported smoking (OR = 0.64; 95% CI: 0.50 to 0.83). There were no significant differences in the rates of nonfatal myocardial infarction and revascularization, and changes in high- and low-density lipoprotein cholesterol levels and diastolic pressure. Health-related quality of life improved to similar levels with cardiac rehabilitation and usual care. The effect of cardiac rehabilitation on total mortality was independent of coronary heart disease diagnosis, type of cardiac rehabilitation, dose of exercise intervention, length of follow-up, trial quality, and trial publication date. CONCLUSION: This review confirms the benefits of exercise-based cardiac rehabilitation within the context of today's cardiovascular service provision.     

Combination Therapy Versus Monotherapy in Reducing Blood Pressure: Meta-analysis on 11,000 Participants from 42 Trials

Objective

To quantify the incremental effect of combining blood pressure-lowering drugs from any 2 classes of thiazides, beta-blockers, angiotensin-converting enzyme inhibitors, and calcium channel blockers over 1 drug alone and to compare the effects of combining drugs with doubling dose.

Methods

Meta-analysis of factorial trials in which participants were randomly allocated to 1 drug alone, another drug alone, both drugs together, or a placebo.

Results

We identified 42 trials (10,968 participants). With a thiazide used alone, the mean placebo-subtracted reduction in systolic blood pressure was 7.3 mm Hg and 14.6 mm Hg combined with a drug from another class. The corresponding reductions were 9.3 mm Hg and 18.9 mm Hg with a beta-blocker, 6.8 mm Hg and 13.9 mm Hg with an angiotensin-converting enzyme, and 8.4 mm Hg and 14.3 mm Hg with a calcium channel blocker. The expected blood pressure reduction from 2 drugs together, assuming an additive effect, closely predicted the observed blood pressure reductions. The ratios of the observed to expected incremental blood pressure reductions from combining each class of drug with any other over that from 1 drug were, respectively, for thiazides, beta-blockers, angiotensin-converting enzyme inhibitors, and calcium channel blockers: 1.04 (95% confidence interval [CI], 0.88-1.20), 1.00 (95% CI, 0.76-1.24), 1.16 (95% CI, 0.93-1.39), and 0.89 (95% CI, 0.69-1.09); the overall average was 1.01 (95% CI, 0.90-1.12). Comparison of our results with those of a published meta-analysis of different doses of the same drug showed that doubling the dose of 1 drug had approximately one fifth of the equivalent incremental effect (0.22 [95% CI, 0.19-0.25]).

Conclusion

Blood pressure reduction from combining drugs from these 4 classes can be predicted on the basis of additive effects. The extra blood pressure reduction from combining drugs from 2 different classes is approximately 5 times greater than doubling the dose of 1 drug.     

Lifestyle interventions to reduce raised blood pressure: a systematic review of randomized controlled trials

PURPOSE: To quantify effectiveness of lifestyle interventions for hypertension. DATA SOURCES: Electronic bibliographic databases from 1998 onwards, existing guidelines, systematic reviews. STUDY SELECTION AND DATA ABSTRACTION: We included randomized, controlled trials with at least 8 weeks' follow-up, comparing lifestyle with control interventions, enrolling adults with blood pressure at least 140/85 mmHg. Primary outcome measures were systolic and diastolic blood pressure. Two independent reviewers selected trials and abstracted data; differences were resolved by discussion. RESULTS: We categorized trials by type of intervention and used random effects meta-analysis to combine mean differences between endpoint blood pressure in treatment and control groups in 105 trials randomizing 6805 participants. Robust statistically significant effects were found for improved diet, aerobic exercise, alcohol and sodium restriction, and fish oil supplements: mean reductions in systolic blood pressure of 5.0 mmHg [95% confidence interval (CI): 3.1-7.0], 4.6 mmHg (95% CI: 2.0-7.1), 3.8 mmHg (95% CI: 1.4-6.1), 3.6 mmHg (95% CI: 2.5-4.6) and 2.3 mmHg (95% CI: 0.2-4.3), respectively, with corresponding reductions in diastolic blood pressure. Relaxation significantly reduced blood pressure only when compared with non-intervention controls. We found no robust evidence of any important effect on blood pressure of potassium, magnesium or calcium supplements. CONCLUSIONS: Patients with elevated blood pressure should follow a weight-reducing diet, take regular exercise, and restrict alcohol and salt intake. Available evidence does not support relaxation therapies, calcium, magnesium or potassium supplements to reduce blood pressure.     

Aliskiren alone or in combination with hydrochlorothiazide in patients with the lower ranges of stage 2 hypertension: The ACQUIRE randomized double-blind study

Patients with stage 2 hypertension (systolic blood pressure [SBP] ≥160mm Hg and/or diastolic blood pressure [DBP] ≥100mm Hg) are at high cardiovascular risk and require intensive blood pressure (BP)-lowering therapy. This randomized double-blind study is the first prospective trial specifically designed to evaluate the direct renin inhibitor aliskiren in patients with a mean sitting SBP ≥160 mm Hg and <180mm Hg (the lower ranges of stage 2 systolic hypertension). After a 2- to 4-week washout period, 688 patients were randomized to once-daily aliskiren/hydrochlorothiazide (HCT) 150/12.5mg or aliskiren 150mg for 1 week and then double the doses for 11 weeks. Baseline BP was 167.1/95.0mm Hg. At week 12, both aliskiren/HCT and aliskiren provided substantial BP reductions from baseline (30.0/12.6 mm Hg and 20.3/8.2 mm Hg, respectively). Aliskiren/HCT lowered BP significantly more than aliskiren (least-squares mean between-treatment differences [95% confidence interval] were -9.7 [-12.0 to -7.4] for SBP and -4.5 [-5.8 to -3.2] for DBP; both P<.0001). Similar BP reductions were seen in the subgroups of patients with isolated systolic hypertension and obesity. Aliskiren, with or without HCT, provides clinically significant BP reductions and may therefore be an effective treatment option in patients with stage 2 hypertension.     

Systematic review and meta-analysis of preterm birth and later systolic blood pressure

Lower birth weight because of fetal growth restriction is associated with higher blood pressure later in life, but the extent to which preterm birth (<37 completed weeks' gestation) or very low birth weight (<1500 g) predicts higher blood pressure is less clear. We performed a systematic review of 27 observational studies that compared the resting or ambulatory systolic blood pressure or diagnosis of hypertension among children, adolescents, and adults born preterm or very low birth weight with those born at term. We performed a meta-analysis with the subset of 10 studies that reported the resting systolic blood pressure difference in millimeters of mercury with 95% CIs or SEs. We assessed methodologic quality with a modified Newcastle-Ottawa Scale. The 10 studies were composed of 1342 preterm or very low birth weight and 1738 term participants from 8 countries. The mean gestational age at birth of the preterm participants was 30.2 weeks (range: 28.8-34.1 weeks), birth weight was 1280 g (range: 1098-1958 g), and age at systolic blood pressure measurement was 17.8 years (range: 6.3-22.4 years). Former preterm or very low birth weight infants had higher systolic blood pressure than term infants (pooled estimate: 2.5 mm Hg [95% CI: 1.7-3.3 mm Hg]). For the 5 highest quality studies, the systolic blood pressure difference was slightly greater, at 3.8 mm Hg (95% CI: 2.6-5.0 mm Hg). We conclude that infants who are born preterm or very low birth weight have modestly higher systolic blood pressure later in life and may be at increased risk for developing hypertension and its sequelae.     

Impaired fasting glucose,blood pressure and cardiovascular disease mortality

Impaired fasting glucose (fasting plasma glucose 6.1 to 6.9 mmol/L [110 to 125 mg/dL]) is a common glycemic disorder which usually progress to diabetes mellitus. The relationships between impaired fasting glucose, other risk factors including blood pressure, and mortality have never been clearly investigated. We studied 63 443 consecutive men (ages 21 to 60 years), each of whom had a routine health examination with a fasting plasma glucose measurement. Men with known ischemic cardiac disease and treatment for diabetes or hypertension were excluded. Impaired fasting glucose was found in 10 773 (17.0%) of these men. Mean body mass index, serum triglyceride and cholesterol levels, and systolic, diastolic, and pulse blood pressure were significantly higher for men with impaired fasting glucose compared with those men with normal fasting glucose (fasting plasma glucose 3.9 to 6.0 mmol/L). When adjusted for confounding variables, relative risk of 8-year cardiovascular mortality associated with impaired fasting glucose was dependent on systolic blood pressure level (1.02 [95% CI: 0.62 to 1.70] when <140 mm Hg and 2.10 [95% CI: 1.16 to 3.80] between 140 and 160 mm Hg). Inversely, relative risk of 8-year cardiovascular mortality associated with moderate systolic hypertension (140 to 159 mm Hg) compared with normal systolic blood pressure (<140 mm Hg) was highly dependent on the glycemic status (2.97 [95% CI: 1.58 to 5.55] for men with impaired fasting glucose compared with 1.35 [95% CI: 0.84 to 2.18] in those with normal fasting glucose). Similar results were found concerning overall mortality. In conclusion, the presence of moderate systolic hypertension can identify subjects with impaired fasting glucose who are at risk of cardiovascular and overall mortality, and vice versa, probably through the metabolic syndrome.     

A meta-analysis comparing the effect of thiazolidinediones on cardiovascular risk factors

BACKGROUND: In patients with type 2 diabetes mellitus, all therapeutic options should be evaluated for their effect on cardiovascular risk factors, in addition to glycemic control. We conducted a meta-analysis of randomized controlled trials of pioglitazone hydrochloride and rosiglitazone maleate in patients with type 2 diabetes to evaluate their effect on glycemic control, lipids, blood pressure, and weight. METHODS: Randomized controlled trials of patients with type 2 diabetes that compared pioglitazone or rosiglitazone with placebo for 12 weeks were included. Primary analysis was to compare thiazolidinediones with placebo. Secondary analysis was to identify whether treatment with pioglitazone differed from rosiglitazone in any outcomes. We calculated weighted mean differences and 95% confidence intervals. RESULTS: Twenty-three randomized controlled trials were identified. Both thiazolidinediones demonstrated similar hemoglobin A(1c) level decreases of 1.0% to 1.5% and similar increases in body weight of approximately 3.0 kg. Pioglitazone significantly lowered triglyceride level (-40 mg/dL [-0.45 mmol/L]; 95% confidence interval [CI], -53 to -26 mg/dL [-0.60 to -0.29 mmol/L]), increased high-density lipoprotein cholesterol (HDL-C) level (+4.6 mg/dL [+0.12 mmol/L]; 95% CI, 3.6 to 5.5 mg/dL [0.09 to 0.14 mmol/L]), and showed neutral effect on low-density lipoprotein cholesterol (LDL-C) and total cholesterol levels. Rosiglitazone significantly increased HDL-C level (+2.7 mg/dL [+0.07 mmol/L]; 95% CI, 2.0 to 3.4 mg/dL [0.05 to 0.09 mmol/L]), but increased LDL-C level (+15 mg/dL [+0.39 mmol/L]; 95% CI, 13 to 17 mg/dL [0.34 to 0.44 mmol/L]), total cholesterol level (+21 mg/dL [+0.54 mmol/L]; 95% CI, 18 to 25 mg/dL [0.47 to 0.65 mmol/L]), and demonstrated neutral effect on triglyceride level (-1.1 mg/dL [-0.12 mmol/L]; 95% CI, -14 to 12 mg/dL [-0.16 to 0.14 mmol/L]). No data were available on pioglitazone and blood pressure. Rosiglitazone had a neutral effect on systolic (-0.7 mm Hg; 95% CI, -2.6 to 1.1 mm Hg) and diastolic (-0.8 mm Hg; 95% CI, -1.8 to 0.3) blood pressure. CONCLUSIONS: Thiazolidinediones have similar effects on glycemic control and body weight. Pioglitazone produced a more favorable lipid profile. Head-to-head comparative trials as well as longer-term cardiovascular outcome studies are needed to determine whether there are differences in efficacy between the 2 thiazolidinediones.     

Effect of fructose on blood pressure: a systematic review and meta-analysis of controlled feeding trials

Concerns have been raised about the adverse effect of fructose on blood pressure. International dietary guidelines, however, have not addressed fructose intake directly. A systematic review and meta-analysis was conducted to assess the effect of fructose in isocaloric exchange for other carbohydrates on systolic, diastolic, and mean arterial blood pressures. Studies were identified using Medline, Embase, and Cochrane databases (through January 9, 2012). Human clinical trials of isocaloric oral fructose exchange for other carbohydrate sources for ≥7 days were included in the analysis. Data were pooled by the generic inverse variance method using random-effects models and expressed as mean differences with 95% CI. Heterogeneity was assessed by the Q-statistic and quantified by I(2). Study quality was assessed using the Heyland Methodological Quality Score. Thirteen isocaloric (n=352) and 2 hypercaloric (n=24) trials met the eligibility criteria. Overall, fructose intake in isocaloric exchange for other carbohydrates significantly decreased diastolic (mean difference: -1.54 [95% CI: -2.77 to -0.32]) and mean arterial pressure (mean difference: -1.16 [95% CI: -2.15 to -0.18]). There was no significant effect of fructose on systolic blood pressure (mean difference: -1.10 [95% CI: -2.46 to 0.44]). The hypercaloric fructose feeding trials found no significant overall mean arterial blood pressure effect of fructose in comparison with other carbohydrates. To confirm these results, longer and larger trials are needed. Contrary to previous concerns, we found that isocaloric substitution of fructose for other carbohydrates did not adversely affect blood pressure in humans.