Nocturnal reduction of blood pressure and the antihypertensive response to a diuretic or angiotensin converting enzyme inhibitor in obese hypertensive patients. TROPHY Study Group

Parental obesity alters offspring blood pressure regulation and cardiovascular responses to stress: role of P2X7R and sex differences

We examined the impact of parental obesity on offspring blood pressure (BP) regulation and cardiovascular responses to stress. Offspring from normal (N) diet-fed C57BL/6J parents were fed either N (NN) or a high-fat (H) diet (NH) from weaning until adulthood. Offspring from obese H diet-fed parents were also fed N (HN) or H diet (HH). Body weight, calorie intake, and fat mass were measured at 22 wk of age when cardiovascular phenotyping was performed. Male and female HH offspring were 15% heavier than NH and 70% heavier than NN offspring. Male HH and HN offspring had elevated BP (121 ± 2 and 115 ± 1 mmHg, by telemetry) compared with male NH and NN offspring (108 ± 6 and 107 ± 3 mmHg, respectively) and augmented BP responses to angiotensin II, losartan, and hexamethonium. Male HH and HN offspring also showed increased BP responses to air-jet stress (37 ± 2 and 38 ± 2 mmHg) compared with only 24 ± 3 and 25 ± 3 mmHg in NH and NN offspring. Baseline heart rate (HR) and HR responses to air-jet stress were similar among groups. In females, BP and cardiovascular responses to stress were similar among all offspring. Male H diet-fed offspring from obese H diet-fed purinoreceptor 7-deficient (HH-P2X7R-KO) parents had normal BP that was similar to control NN-P2X7R-KO offspring from lean parents. These results indicate that parental obesity leads to increased BP and augmented BP responses to stress in their offspring in a sex-dependent manner, and the impact of parental obesity on male offspring BP regulation is markedly attenuated in P2X7R-KO mice.

Long-term intake of miso soup decreases nighttime blood pressure in subjects with high-normal blood pressure or stage I hypertension

The present study aimed to investigate the effects of the combination of Marukome Nenrin miso, which has natriuretic effects, and Marukome MK-34-1 miso, which has potent angiotensin converting enzyme inhibitory effects, on blood pressure (BP) in humans. A total of 40 subjects aged 40–69 years with high-normal BP or stage I hypertension were randomly assigned to two groups: 1) the miso group (32 g 2:1 w/w Nenrin and MK-34-1 with 3.8 g salt/day) or 2) the control soy food group (14.4 g soy food with 0.2 g salt/day). The levels of major nutrients were equal in the miso and control food servings, except for the fiber and Na levels, which were higher in the miso food serving. Daytime and nighttime BP were measured with an automated BP monitor. Compared with the soy food intake, miso intake for 8 weeks did not affect daytime clinical BP but significantly decreased nighttime BP without affecting pulse rate (PR). Moreover, miso shifted the nighttime BP profile to lower levels than those at baseline. Soy food intake did not change the nighttime BP profile after 8 weeks. Miso intake also tended to reduce nighttime BP in a subgroup with stage 1 hypertension compared with the results of the soy food group participants and shifted the nighttime BP profile toward lower levels than those recorded at baseline. Miso intake did not influence lipid or glucose metabolism. In conclusion, this is the first report showing that miso reduces nighttime BP in humans. Miso may do so by shrinking the fluid spaces in the body and/or deactivating the adrenergic nervous system.

Non-dipping blood pressure pattern and new-onset diabetes in a 21-year follow-up

Purpose: Non-dipping blood pressure (BP) pattern has been associated with metabolic changes and cardiovascular events. With regard of diabetes, studies are scarce. Our aim was to investigate if there is an association between changes in dipping patterns and incidence of diabetes. Materials and methods: A 24-h ambulatory BP measurement was recorded in addition to other laboratory measurements, and a questionnaire and physical examination were carried out in the baseline study and after 21-year follow-up among a study population (n = 449) consisting of randomly selected middle-aged Finnish females and males without diabetes. Results: 128 (28.5%) developed diabetes during the follow-up. The incidence of new-onset diabetes was the highest, 41.0%, among those subjects who were non-dippers (their systolic BP declined <10% from daytime to nighttime) in the baseline and also in the follow-up study, while the incidence of diabetes was 19.6% in the dipper - dipper (a nighttime decline of systolic BP 10% or more) group (p = 0.003). The difference remained statistically significant after adjustment with age, sex, body mass index, fasting glucose, triglycerides, and insulin levels, smoking status, 24-h mean systolic BP, high-sensitivity C-reactive protein, estimated glomerular filtration and diuretics use. In logistic regression analysis, the non-dipper - non-dippers were at higher risk of diabetes compared with dipper - dipper group (OR = 2.27, 95% CI: 1.13-4.56, p = 0.022). Conclusions: Our prospective study shows that there is an independent association between non-dipping BP pattern and the incidence of diabetes in a 21-year follow-up.

The association of nocturnal hypertension and nondipping blood pressure with treatment-resistant hypertension: The Jackson Heart Study

Apparent treatment-resistant hypertension (aTRH), nocturnal hypertension, and nondipping blood pressure (BP) have shared risk factors. The authors studied the association between aTRH and nocturnal hypertension and aTRH and nondipping BP among 524 black Jackson Heart Study participants treated for hypertension. Nocturnal hypertension was defined by mean nighttime systolic BP ≥120 mm Hg or diastolic BP ≥70 mm Hg. Nondipping BP was defined by mean nighttime to daytime systolic BP ratio >0.90. aTRH was defined by mean clinic systolic BP ≥140 mm Hg and/or diastolic BP ≥90 mm Hg with three medication classes or treatment with four or more classes. The risk for developing aTRH associated with nondipping BP and nocturnal hypertension was estimated. After multivariable adjustment, participants with aTRH were more likely to have nocturnal hypertension (prevalence ratio, 1.20; 95% confidence interval, 1.03-1.39) and nondipping (prevalence ratio, 1.25; 95% confidence interval, 1.09-1.43). Over a median 7.3 years of follow-up, nocturnal hypertension and nondipping BP at baseline were not associated with developing aTRH after adjustment.

Circadian blood pressure patterns and blood pressure control in patients with chronic kidney disease

BACKGROUND AND AIMS

Hypertension is a major risk factor for chronic kidney disease (CKD), and CKD progression is associated with suboptimal blood pressure (BP) control. Here we evaluate the impact of CKD on the attainment of BP control and the circadian BP profile in older subjects.

METHODS

In this observational study, we studied 547 patients referred to the hypertension clinic, of whom 224 (40.9%) had CKD. Blood pressure (BP) control and circadian BP patterns were evaluated by 24-hour ambulatory BP monitoring. Circadian BP variability was measured as the within-subject SD of BP, the percentage of measurements exceeding normal values, hypotension, and dipping status.

RESULTS

The attainment of adequate BP control was similar in subjects with or without CKD (around 31%). Logistic regression analysis indicated that CKD was not a determinant of adequate BP control (OR 1.004; 95% CI 0.989-1.019; p = 0.58). Patients with CKD presented as twice as higher prevalence of reverse dipper (night-time peak) for systolic BP and episodes of hypotension during daytime, independently of BP control.

CONCLUSIONS

Knowledge of the circadian pattern of BP in hypertensive subjects with CKD could inform better than attainment of BP target about risky condition for CKD progression and cognitive decline and allow a more personalized antihypertensive treatment.

The SONG (Salt intake and OrigiN from General foods) Study - A Large-scale Survey of the Eating Habits and Dietary Salt Intake in the Working-age Population

Objective Dietary salt reduction is important for the prevention and treatment of lifestyle-related diseases, including hypertension. Thus, in order to follow a strict low-salt diet, it is necessary to assess one's salt intake and to become aware of the importance of salt reduction. Methods More than 2,000 employees of a company, who received a periodic health checkup, participated in the present study. They assessed their day-to-day diet-related lifestyle, using the Salt Check Sheet, and we analyzed the correlations among the Salt Check Sheet scores, the daily salt intake (as estimated by a spot urine sample), and the results of the periodic health checkup. Results In the overall survey population, we only found a weak correlation between the salt check scores and the salt intake. In a subgroup analysis, significant correlations between these two variables were observed among untreated hypertensive participants, but not among treated hypertensive participants. We examined the association between 13 individual questionnaire items and the estimated daily salt intake using a multivariate linear regression model and found that only 5 of the 13 questionnaire items were correlated with the daily salt intake. Conclusion We found that a Salt Check Sheet composed of the 5 items that showed a strong correlation with the salt intake might be more useful for periodic health checks of the working-age population.

Review: Renin-angiotensin-aldosterone system intervention in the cardiometabolic syndrome and cardio-renal protection

The metabolic syndrome, also known as the cardiometabolic syndrome (CMS), is a state of metabolic and vascular dysregulation that is associated with activation of the renin-angiotensin-aldosterone system (RAAS). Clinical components of the CMS include central or visceral obesity, hypertension (HTN), dyslipidemia, insulin resistance/hyperinsulinemia, and microalbuminuria that collectively convey increases in oxidative stress, inflammation, and subsequent endothelial dysfunction. The cardio-renal inflammation and oxidative stress enhanced in the CMS increases the risk for cardiovascular disease (CVD) and renal disease end-points such as stroke, congestive heart failure, and chronic kidney disease (CKD). The development of proteinuria is known to herald progressive kidney disease (e.g. CKD) and both are now well accepted as CVD risk factors. Evidence suggests a role for visceral obesity, insulin resistance/hyperinsulinemia, HTN, and other components of the CMS lead to an increased risk for proteinuria and progressive loss of renal function. Intervention with agents that block the RAAS (e.g. ACE inhibitors and Angiotensin type 1 receptor blockers) have been shown to reduce proteinuria, CKD progression, and CVD events. Herein, we will examine the relationship between RAAS intervention and reductions in CKD and CVD events.

Obesity and insulin resistance in resistant hypertension: implications for the kidney

There is recognition that the obesity epidemic contributes substantially to the increasing incidence of CKD and resistant hypertension (HTN). The mechanisms by which obesity promotes resistance are an area of active interest and intense investigation. It is thought that increases in visceral adiposity lead to a proinflammatory, pro-oxidative milieu that promote resistance to the metabolic actions of insulin. This resistance to insulin at the level of skeletal muscle tissue impairs glucose disposal/utilization through actions on the endothelium that include vascular rarefaction, reductions in vascular relaxation, and vascular remodeling. Insulin resistance derived from increased adipose tissue and obesity has system-wide implications for other tissue beds such as the kidney that affects blood pressure regulation. The additional autocrine and paracrine activities of adipose tissue contribute to inappropriate activation of the renin-angiotensin-aldosterone system and the sympathetic nervous system that promote kidney microvascular remodeling, stiffness, and sodium (Na(+)) retention that in turn promote HTN and in the CKD patient, resistance. In this review, we will summarize the important mechanisms that link obesity to CKD as they relate to resistant HTN.

Blood pressure-lowering efficacy of monotherapy with thiazide diuretics for primary hypertension

BACKGROUND

Hypertension is a modifiable cardiovascular risk factor. Although it is established that low-dose thiazides reduce mortality as well as cardiovascular morbidity, the dose-related effect of thiazides in decreasing blood pressure has not been subject to a rigorous systematic review. It is not known whether individual drugs within the thiazide diuretic class differ in their blood pressure-lowering effects and adverse effects.

OBJECTIVES

To determine the dose-related decrease in systolic and/or diastolic blood pressure due to thiazide diuretics compared with placebo control in the treatment of patients with primary hypertension. Secondary outcomes included the dose-related adverse events leading to patient withdrawal and adverse biochemical effects on serum potassium, uric acid, creatinine, glucose and lipids.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL 2014, Issue 1), Ovid MEDLINE (1946 to February 2014), Ovid EMBASE (1974 to February 2014) and ClinicalTrials.gov.

SELECTION CRITERIA

We included double-blind, randomized controlled trials (RCTs) comparing fixed-dose thiazide diuretic monotherapy with placebo for a duration of 3 to 12 weeks in the treatment of adult patients with primary hypertension.

DATA COLLECTION AND ANALYSIS

Two authors independently screened articles, assessed trial eligibility, extracted data and determined risk of bias. We combined data for continuous variables using a mean difference (MD) and for dichotomous outcomes we calculated the relative risk ratio (RR) with 95% confidence interval (CI).

MAIN RESULTS

We included 60 randomized, double-blind trials that evaluated the dose-related trough blood pressure-lowering efficacy of six different thiazide diuretics in 11,282 participants treated for a mean duration of eight weeks. The mean age of the participants was 55 years and baseline blood pressure was 158/99 mmHg. Adequate blood pressure-lowering efficacy data were available for hydrochlorothiazide, chlorthalidone and indapamide. We judged 54 (90%) included trials to have unclear or high risk of bias, which impacted on our confidence in the results for some of our outcomes.In 33 trials with a baseline blood pressure of 155/100 mmHg, hydrochlorothiazide lowered blood pressure based on dose, with doses of 6.25 mg, 12.5 mg, 25 mg and 50 mg/day lowering blood pressure compared to placebo by 4 mmHg (95% CI 2 to 6, moderate-quality evidence)/2 mmHg (95% CI 1 to 4, moderate-quality evidence), 6 mmHg (95% CI 5 to 7, high-quality evidence)/3 mmHg (95% CI 3 to 4, high-quality evidence), 8 mmHg (95% CI 7 to 9, high-quality evidence)/3 mmHg (95% CI 3 to 4, high-quality evidence) and 11 mmHg (95% CI 6 to 15, low-quality evidence)/5 mmHg (95% CI 3 to 7, low-quality evidence), respectively.Direct comparison of doses did not show evidence of dose dependence for blood pressure-lowering for any of the other thiazides for which RCT data were available: bendrofluazide, chlorthalidone, cyclopenthiazide, metolazone or indapamide.In seven trials with a baseline blood pressure of 163/88 mmHg, chlorthalidone at doses of 12.5 mg to 75 mg/day reduced average blood pressure compared to placebo by 12.0 mmHg (95% CI 10 to 14, low-quality evidence)/4 mmHg (95% CI 3 to 5, low-quality evidence).In 10 trials with a baseline blood pressure of 161/98 mmHg, indapamide at doses of 1.0 mg to 5.0 mg/day reduced blood pressure compared to placebo by 9 mmHg (95% CI 7 to 10, low-quality evidence)/4 (95% CI 3 to 5, low-quality evidence).We judged the maximal blood pressure-lowering effect of the different thiazides to be similar. Overall, thiazides reduced average blood pressure compared to placebo by 9 mmHg (95% CI 9 to 10, high-quality evidence)/4 mmHg (95% CI 3 to 4, high-quality evidence).Thiazides as a class have a greater effect on systolic than on diastolic blood pressure, therefore thiazides lower pulse pressure by 4 mmHg to 6 mmHg, an amount that is greater than the 3 mmHg seen with angiotensin-converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs) and renin inhibitors, and the 2 mmHg seen with non-selective beta-blockers. This is based on an informal indirect comparison of results observed in other Cochrane reviews on ACE inhibitors, ARBs and renin inhibitors compared with placebo, which used similar inclusion/exclusion criteria to the present review.Thiazides reduced potassium, increased uric acid and increased total cholesterol and triglycerides. These effects were dose-related and were least for hydrochlorothiazide. Chlorthalidone increased serum glucose but the evidence was unclear for other thiazides. There is a high risk of bias in the metabolic data. This review does not provide a good assessment of the adverse effects of these drugs because there was a high risk of bias in the reporting of withdrawals due to adverse effects.

AUTHORS' CONCLUSIONS

This systematic review shows that hydrochlorothiazide has a dose-related blood pressure-lowering effect. The mean blood pressure-lowering effect over the dose range 6.25 mg, 12.5 mg, 25 mg and 50 mg/day is 4/2 mmHg, 6/3 mmHg, 8/3 mmHg and 11/5 mmHg, respectively. For other thiazide drugs, the lowest doses studied lowered blood pressure maximally and higher doses did not lower it more. Due to the greater effect on systolic than on diastolic blood pressure, thiazides lower pulse pressure by 4 mmHg to 6 mmHg. This exceeds the mean 3 mmHg pulse pressure reduction achieved by ACE inhibitors, ARBs and renin inhibitors, and the 2 mmHg pulse pressure reduction with non-selective beta-blockers as shown in other Cochrane reviews, which compared these antihypertensive drug classes with placebo and used similar inclusion/exclusion criteria.Thiazides did not increase withdrawals due to adverse effects in these short-term trials but there is a high risk of bias for that outcome. Thiazides reduced potassium, increased uric acid and increased total cholesterol and triglycerides.

The heart in obesity-hypertension

There is growing recognition that obesity is reaching epidemic proportions throughout the world. In adults, obesity is associated with increased cardiovascular morbidity and mortality. A series of endocrine, metabolic and hemodynamic mechanisms have been responsible for the development of obesity-hypertension. These mechanisms include: a suppressed biologic activity and availability of natriuretic peptide, increased sympathetic adrenergic activity, release of angiotensin ll from adipocytes and activation of the renin-angiotensin-aldosterone system, leptin resistance, chronic hyperleptinemia and hyperinsulinemia. The systemic hemodynamic profile of obesity includes high intravascular volume, increased cardiac output and inappropriately normal peripheral resistance. The cardiovascular adaptations to these changes include changes in vascular responsiveness and concentric-eccentric left ventricular hypertrophy, and may be responsible for increased risk of congestive heart failure, arrhythmia and sudden death.

Difference in blood pressure response to ACE-Inhibitor monotherapy between black and white adults with arterial hypertension: a meta-analysis of 13 clinical trials

Background

Among African-Americans adults, arterial hypertension is both more prevalent and associated with more complications than among white adults. Hypertension is also epidemic among black adults in sub-Saharan Africa. The treatment of hypertension among black adults may be complicated by lesser response to certain classes of anti-hypertensive agents.

Methods

We systematically searched literature for clinical trials of ACE-inhibitors among hypertensive adults comparing blood pressure response between whites and blacks. Meta-analysis was performed to determine the difference in systolic and diastolic blood pressure response. Further analysis including meta-regressions, funnel plots, and one-study-removed analyses were performed to investigate possible sources of heterogeneity or bias.

Results

In a meta-analysis of 13 trials providing 17 different patient groups for evaluation, black race was associated with a lesser reduction in systolic (mean difference: 4.6 mmHg (95% CI 3.5-5.7)) and diastolic (mean difference: 2.8 mmHg (95% CI 2.2-3.5)) blood pressure response to ACE-inhibitors, with little heterogeneity. Meta-regression revealed only ACE-inhibitor dosage as a significant source of heterogeneity. There was little evidence of publication bias.

Conclusions

Black race is consistently associated with a clinically significant lesser reduction in both systolic and diastolic blood pressure to ACE-inhibitor therapy in clinical trials in the USA and Europe. In black adults requiring monotherapy for uncomplicated hypertension, drugs other than ACE-inhibitors may be preferred, though the proven benefits of ACE-inhibitors in some sub-groups and the large overlap of response between blacks and whites must be remembered. These data are particularly important for interpretation of clinical drug trials for hypertensive black adults in sub-Saharan Africa and for the development of treatment recommendations in this population.

Can nocturnal hypertension predict cardiovascular risk?

Nocturnal hypertension and non-dipping of blood pressure during sleep are distinct entities that often occur together and are regarded as important harbingers of poor cardiovascular prognosis. This review addresses several aspects related to these blood pressure abnormalities including definitions, diagnostic limitations, pathogenesis and associated patient profiles, prognostic significance, and therapeutic strategies. Taken together, persistent nocturnal hypertension and non-dipping blood pressure pattern, perhaps secondary to abnormal renal sodium handling and/or altered nocturnal sympathovagal balance, are strongly associated with deaths, cardiovascular events, and progressive loss of renal function, independent of daytime and 24-hour blood pressure. Several pharmacological and non-pharmacological approaches may restore nocturnal blood pressure and circadian blood pressure rhythm to normal; however, whether this translates to a clinically meaningful reduction in unfavorable cardiovascular and renal consequences remains to be seen.

Obesity and hypertension: mechanisms, cardio-renal consequences, and therapeutic approaches

The increasing prevalence of obesity in the industrialized world is causing an alarming epidemic. Almost 70% of American adults are overweight or obese. The link between increasing body weight and hypertension is well established. Obesity hypertension through metabolic, endocrinic, and systemic hemodynamic alteration causes structural vascular and cardiac adaptations that trigger concentric, eccentric left ventricular hypertrophy and electrophysiological changes, which may increase the risk for congestive heart failure and sudden cardiac death as a result of arrhythmias. The increased renal blood flow in conjunction with a decreased renal vascular resistance causes renal hyperperfusion and hyperfiltration. Such changes lead to glomerulomegaly, focal segmental glomerulosclerosis, tubulointerstitial inflammation, and fibrosis that characterize the renal damage in obese hypertensive subjects. We propose that weight reduction, with the addition of other nonpharmacological approaches that included exercise and reduction in alcohol intake, should be the first choice to treat obesity hypertension. Salt restriction may be helpful only in salt-sensitive patients. The benefits of diet in obese patients include improvement of insulin sensitivity, reduction in sympathetic nervous and renin angiotensin system activities, and restoration of leptin sensitivity. As a consequence of these and other metabolic changes, the previously described systemic and renal hemodynamic alterations improved and the cardiovascular and renal morphological changes induced by obesity were lessened. After reviewing the medications available, we believe that owing to the cardiovascular and renal morbidity and mortality that characterized obesity hypertension, the ACEI or ARBs offer the best cardio-renal protection and should be the pharmacologic treatment of choice. If these alone do not control BP adequately, then a low-dose diuretic should be added as a second approach. Although we strongly believe in our proposal, more multicenter long-term clinical pharmacological trials are needed to evaluate the efficacy and safety of the antihypertensive approaches in the treatment of obesity hypertension.

Magnitude of the early morning blood pressure surge in untreated hypertensive patients: a pooled analysis

OBJECTIVES

A post hoc analysis was performed to assess the magnitude of the early morning blood pressure surge (EMBPS), which is associated with peak cardiovascular risk, in untreated hypertensive patients enrolled in two sister studies (Prospective, Randomised Investigation of the Safety and efficacy of MICARDIS vs. ramipril using ambulatory blood pressure monitoring I and II) with identical design.

METHODS

In adults with a mild-to-moderate primary hypertension and no significant comorbidities, 24-h ambulatory blood pressure monitoring was conducted after a 2- to 4-week placebo run-in period and before treatment initiation. Individual blood pressure measurements at 20-min intervals were analysed.

RESULTS

In 1419 hypertensive patients with normal sleeping times, blood pressure displayed a typical circadian rhythm, with a mean EMBPS of 29/24 mmHg. An EMBPS of >or= 25 mmHg was observed in around 60% of patients. The surge was significantly increased with smoking, alcohol consumption, longer sleep, later waking times, and increased blood pressure variability during waking and sleeping. The magnitude of the EMBPS was significantly reduced in Black vs. White patients. The surge was not affected by gender, body mass index or duration of hypertension. Further analysis showed that ethnicity, alcohol consumption and smoking were all found to have a significant impact on surge around waking and age, sleep duration and sleep blood pressure variability were all found to have an effect on the prewake surge.

CONCLUSIONS

In untreated hypertensive patients, the magnitude of the EMBPS is significant when compared with the 24-h mean and is affected by individual patient characteristics. In light of these findings, physicians should understand the importance of 24-h blood pressure control and the modification of certain lifestyle factors as ways of reducing the EMBPS.

Will tomorrow's medicines work for everyone?

Throughout much of the world, 'race' and 'ethnicity' are key determinants of health. For example, African Americans have, by some estimates, a twofold higher incidence of fatal heart attacks and a 10% higher incidence of cancer than European Americans, and South Asian- or Caribbean-born British are approximately 3.5 times as likely to die as a direct result of diabetes than are British of European ancestry. The health care that people receive also depends on 'race' and 'ethnicity'. African Americans are less likely to receive cancer-screening services and more likely to have late-stage cancer when diagnosed than European Americans. Health disparities such as these are one of the greatest social injustices in the developed world and one of the most important scientific and political challenges.

Gender difference in the response to an angiotensin-converting enzyme inhibitor and a diuretic in hypertensive patients of African descent

BACKGROUND

The efficacy of angiotensin-converting enzyme (ACE) inhibitors in decreasing blood pressure in African patients is controversial.

OBJECTIVE

We examined the ambulatory blood pressure (ABP) response to a diuretic and an ACE inhibitor in hypertensive patients of East African descent and evaluated the individual characteristics that determined treatment efficacy.

DESIGN

A single-blind randomized AB/BA crossover design.

SETTING

Hypertensive families of East African descent from the general population in the Seychelles.

PARTICIPANTS

Fifty-two (29 men and 23 women) out of 62 eligible hypertensive patients were included.Main outcome measures ABP response to 20 mg lisinopril (LIS) daily and 25 mg hydrochlorothiazide (HCT) daily given for a 4-week period. Results The daytime systolic/diastolic ABP response to HCT was 4.9 [95% confidence interval (CI) 1.2-8.6]/3.6 (1.0-6.2) mmHg for men and 12.9 (9.2-16.6)/6.3 (3.7-8.8) mmHg for women. With LIS the response was 18.8 (15.0-22.5)/14.6 (12.0-17.1) mmHg for men and 12.4 (8.7-16.2)/7.7 (5.1-10.2) mmHg for women. The night-time systolic/diastolic response to HCT was 5.0 (0.6-9.4)/2.7 [(-0.4)-5.7] mmHg for men and 11.5 (7.1-16.0)/5.7 (2.6-8.8) mmHg for women, and to LIS was 18.7 (14.2-22.1)/15.4 (12.4-18.5) mmHg for men and 3.5 [(-1.0)-7.9]/2.3 [(-0.8)-5.4] mmHg for women. Linear regression analyses showed that gender is an independent predictor of the ABP responses to HCT and to LIS.

CONCLUSIONS

Hypertensive patients of African descent responded better to LIS than to HCT. Men responded better to LIS than to HCT and women responded similarly to both drugs.

Overlap Between Whites and Blacks in Response to Antihypertensive Drugs

On average, whites and blacks differ in their response to specific antihypertensive drugs. These differences are often highlighted in reviews and practice guidelines. However, there is wide variation in drug-associated changes in blood pressure within each race. The goal of this meta-analysis is to quantitate how often whites and blacks have similar responses to specific antihypertensive drugs. Computerized searches of MEDLINE (1983 to March 2003) and manual searches of references listed in identified articles were performed. Studies were included if they provided race-specific changes in blood pressure. Fifteen studies with a total of 9307 white subjects and 2902 black subjects were analyzed. For drug-associated changes in diastolic blood pressure, the mean difference between whites and blacks ranged from 0.6 to 3.0 mm Hg while the standard deviation within each race ranged from 5.0 to 10.1 mm Hg. The percentage of whites and blacks with similar drug-associated changes in diastolic blood pressure was 90% (95% confidence interval: 81 to 99) for diuretics, 90% (95% CI: 83 to 97) for beta-blockers, 95% (95% CI: 92 to 98) for calcium channel blockers, and 81% (95% CI: 76 to 86) for angiotensin converting enzyme inhibitors. The percentage of whites and blacks with similar drug-associated changes in systolic blood pressure ranged from 83% to 93%. In conclusion, the majority of whites and blacks have similar responses to commonly used antihypertensive drugs. Clinical decisions to use a specific drug should be based on other considerations such as efficacy in individual patients, compelling indications, and cost.

Response to six classes of antihypertensive medications by body mass index in a randomized controlled trial

Blood pressure increases with increasing body mass index (BMI) and BMI is linearly related to blood pressure in population studies. Obesity has been said to cause resistance to antihypertensive medications. We compared short-term and 1-year blood pressure response by BMI category and weight change with hydrochlorothiazide, atenolol, diltiazem-SR, captopril, clonidine, prazosin, or placebo in 1292 male veterans. Drug doses were titrated to achieve goal diastolic blood pressure <90 mm Hg over 4-8 weeks. Patients who achieved goal blood pressure were maintained for 1 year. BMI did not predict change in systolic, diastolic or pulse pressures during titration for any drug. At 1 year obese patients (BMI >30) were 2.5 times more likely to have diastolic blood pressure controlled by atenolol than normal weight (BMI <27) patients (p=0.01). Only prazosin patients gained weight: 1.7 lb (end-titration, p<0.0001; 1-year, p=0.02). Obesity does not appear to cause resistance to antihypertensive medications.

Sympathovagal balance, nighttime blood pressure, and QT intervals in normotensive obese women

OBJECTIVE

We describe associations among the heart-rate-corrected QT (QTc) interval, QTc dispersion (QTc-d), circadian BP variation, and autonomic function in obese normotensive women and the effect of sustained weight loss.

RESEARCH METHODS AND PROCEDURES

In 71 obese (BMI = 37.14 +/- 2.6 kg/m(2)) women, 25 to 44 years of age, circadian BP variations (24-hour ambulatory BP monitoring), autonomic function (power spectral analysis of RR interval oscillations), and cardiac repolarization times (QTc-d and QTc interval) were recorded at baseline and after 1 year of a multidisciplinary program of weight reduction.

RESULTS

Compared with nonobese age-matched women (n = 28, BMI = 23 +/- 2.0 kg/m(2)), obese women had higher values of QTc-d (p < 0.05) and QTc (p < 0.05), an altered sympathovagal balance (ratio of low-frequency/high-frequency power, p < 0.01), and a blunted nocturnal drop in BP (p < 0.01). In obese women, QTc-d and the QTc interval correlated with diastolic nighttime BP (p < 0.01) and sympathovagal balance (p < 0.01). Waist-to-hip ratio, free fatty acids, and plasma insulin levels correlated with QT intervals and reduced nocturnal drops in both systolic and diastolic BP and sympathovagal balance (p < 0.01). After 1 year, obese women lost at least 10% of their original weight, which was associated with decrements of QTc-d (p < 0.02), the QTc interval (p < 0.05), nighttime BP (p < 0.01), and sympathovagal balance (p < 0.02).

DISCUSSION

Sustained weight loss is a safe method to ameliorate diastolic nighttime BP drop and sympathetic overactivity, which may reduce the cardiovascular risk in obese women.

Adipose tissue as an endocrine organ: role of leptin and adiponectin in the pathogenesis of cardiovascular diseases

Obesity, the most common nutritional disorder in industrial countries, is associated with increased cardiovascular mortality and morbidity. Nevertheless, the molecular basis linking obesity with cardiovascular disturbances have not yet been fully clarified. Recent advances in the biology of adipose tissue indicate that it is not simply an energy storage organ, but also a secretory organ, producing a variety of bioactive substances, including leptin and adiponectin, that may influence the function as well as the structural integrity of the cardiovascular system. Leptin, besides being a satiety signal for the central nervous system and to be related to insulin and glucose metabolism, may also play an important role in regulating vascular tone because of the widespread distribution of functional receptors in the vascular cells. On the other hand, the more recently discovered protein, adiponectin, seems to play a protective role in experimental models of vascular injury, in probable relation to its ability to suppress the attachment of monocytes to endothelial cells, which is an early event in the atherosclerotic process. There is already considerable evidence linking altered production of some adipocyte hormones with the cardiovascular complications of obesity. Therefore, the knowledge of alterations in the endocrine function of adipose tissue may help to further understand the high cardiovascular risk associated with obesity.

A comparison of selected antihypertensives and the use of conventional vs ambulatory blood pressure in the detection and treatment of hypertension

This multicenter, randomized, double-blind, parallel group study was undertaken to determine the effectiveness of selected antihypertensives (doxazosin, amlodipine, enalapril, and bendrofluazide) in maintaining 24-hour control of blood pressure (BP). The predictive value of ambulatory (A)BP versus clinic (C)BP measurements as a method for detecting patients with hypertension was also evaluated. A total of 204 patients were screened and of these 110 were diagnosed as mild to moderately hypertensive with clinic diastolic BP 100-110 mm Hg (> or =95 mm Hg in patients with coronary heart disease risk factors). The 4 antihypertensives were all equally effective at controlling BP over 24 h, as shown by 24-hour ABP measurements. The incidence of adverse events was similar for all 4 treatment groups; headache was the most common event, being reported by 22 patients (20%). There was a clinically relevant reduction in total cholesterol for the doxazosin (-15.4 mg/dl) and amlodipine (-11.6 mg/dl) treatment groups in comparison with enalapril and bendrofluazide. Our results from ABP measurements suggest that the antihypertensives studied are effective first-line therapy in the regulation of hypertension and that ABP is a reproducible measure. ABP may also be useful in identifying patients with various types of high BP, for instance those with 'white coat' hypertension, enabling more accurate screening and diagnosis.

Obesity-hypertension: the effects on cardiovascular and renal systems

Longitudinal and cross-sectional studies suggest that a large number of obese patients have a high prevalence of hypertension. This association causes the following changes: insulin and leptin resistance with a suppressed biologic activity of natriuretic peptide, which contributes to sodium retention with concomitant expanded cardiopulmonary volume and increased cardiac output. The cellular metabolism of cations may be altered in obesity and may lead to changes in vascular responsiveness and increased vascular resistance. These changes lead to structural adaptations in the heart characterized by concentric-eccentric left ventricular hypertrophy. The hypertrophic condition provides the basis for the development of congestive heart failure and cardiac arrhythmias that may explain the higher rates of cardiac sudden death in those patients. In the kidneys, obesity hypertension may initiate a derangement of renal function. The increased deposit of interstitial cells and of extracellular matrix between the tubules induces higher interstitial hydrostatic pressure and tubular sodium reabsorption. The consequent increase in renal flow and glomerular filtration enhances albuminuria excretion and the susceptibility to the development of renal damage. In summary, the hemodynamic and structural adaptations related to obesity hypertension is the cause of greater risk for adverse cardiovascular and renal events.

Hormone replacement therapy and 24-hour blood pressure profile of postmenopausal women

Menopause is associated with an increase in blood pressure (BP) and a decrease in physiologic nocturnal BP fall. These factors may play a role in the increased risk of cardiovascular events after menopause. Some studies indicate that transdermal estrogen replacement therapy may help restore the 24-h BP profile, but data on the effect of oral conjugated estrogens are lacking. We compared 24-h ambulatory BP profiles of 42 postmenopausal women not receiving hormone replacement therapy (HRT) and 20 women receiving HRT. HRT was associated with a significant increase in the proportion of dippers (50% in women not receiving HRT and 80% in women receiving HRT, P = .048). Increase in nocturnal dipping may account, in part, for the beneficial cardiovascular effects of HRT.

Changes of nocturnal blood pressure dipping status in hypertensives by nighttime dosing of alpha-adrenergic blocker, doxazosin : results from the HALT study

Abnormal nocturnal blood pressure (BP) dipping status may be partly determined by nocturnal sympathetic activity. We studied the effect of nighttime dosing of an alpha(1)-adrenergic blocker, doxazosin, on the BP dipping status of 118 hypertensives, all of whom underwent 24-hour ambulatory BP monitoring before and after treatment. The mean nighttime/daytime ratio of systolic BP was increased (0.91 after therapy versus 0.89 at baseline, P<0.05). The patients were initially divided into 4 groups on the basis of their dipping status at the baseline assessment: 18 (15%) were extreme dippers, with a nighttime systolic BP fall of at least 20% of daytime BP; 46 (39%) were dippers (fall between 10% and 20%); 48 (41%) were nondippers (fall between 0% and 10%); and 6 (5%) were risers (nocturnal increase of systolic BP). A shift in dipping status toward less nocturnal BP dipping was observed after doxazosin therapy (P<0.05). Dipping status was determined by nighttime more than by daytime BP, and this was not explained by differences in the number of daytime and nighttime readings. The effects of doxazosin on the mean nocturnal systolic BP changes were an increase of 4.3 mm Hg in extreme dippers and decreases of 0.7 mm Hg in dippers, 12 mm Hg in nondippers, and 18 mm Hg in risers; the reduction was only significant in the latter 2 groups (both P<0.01). To estimate the effects of regression to the mean on the changes in dipping status, we also defined dipping status with the average of the BPs before and after doxazosin and found no difference in the degree of nighttime BP reduction among each group. The reduction of daytime BP was now significantly greater in the subgroups with less dipping: 6. 4 mm Hg for extreme dippers and 16 mm Hg for risers (P<0.05). In conclusion, nighttime dosing with doxazosin markedly affects the nocturnal BP dipping status of hypertensives, but the apparently greater reduction in nighttime pressure in nondippers and risers may be, at least partly, due to the effect of regression to the mean. The most important determinants of the effect of doxazosin were the absolute BP levels, both day and night, rather than dipping status per se.

Obesidade, hipertensão arterial e suas influências sobre a massa e função do ventrículo esquerdo

Para avaliar as influências da obesidade e da hipertensão sobre a massa de ventrículo esquerdo (MVE), estudamos 121 mulheres divididas em 4 grupos: não-obesas normotensas (n = 25), não-obesas hipertensas (n = 30), obesas normotensas (n = 24) e obesas hipertensas (n = 42) quanto a parâmetros antropométricos, ecocardiográficos e de monitorização ambulatorial da pressão arterial (MAPA). As pacientes obesas hipertensas apresentaram maior MVE que os outros grupos - não-obesas normotensas, não-obesas hipertensas e obesas normotensas (167 ± 38,8 vs. 113 + 26,4; vs. 133 ± 26,5; vs. 132 ± 29,2g; p < 0,05, respectivamente) e maior diâmetro de átrio esquerdo (AE) quando comparadas aos grupos de não-obesas, tanto normotensas como hipertensas (36 ± 4,3 vs. 33 ± 5,1; vs. 35 ± 3,9mm; p < 0,05, respectivamente). Obesas normotensas apresentaram MVE similar à do grupo não-obesas hipertensas (133 ± 26,5 vs. 132 ± 29,5g; NS) e aumento de AE quando comparadas às não-obesas normotensas (35 ± 3,9 vs. 31 ± 4,6mm; p < 0,05). Detectou-se correlação entre a circunferência da cintura e a razão cintura-quadril com os níveis pressóricos à MAPA, assim como entre estas medidas e parâmetros ecocardiográficos que avaliam a massa cardíaca; o índice de massa corporal só se correlacionou ao diâmetro do AE. A correção da MVE pela altura ao invés da superfície corpórea aumentou a prevalência de hipertrofia de VE nas obesas (10,6 vs. 36,7%, p < 0,01), mas não nas não-obesas. Ausência de descenso noturno da pressão arterial sistólica à MAPA (non-dipper) foi mais prevalente nas pacientes obesas, hipertensas ou não; entretanto, as obesas hipertensas non-dippers não diferiram das dippers quanto à MVE. Nossos dados demonstram que a obesidade associada à hipertensão aumenta a MVE de modo mais importante do que as condições isoladamente. Concluímos, ainda, que pacientes obesas também apresentam alta freqüência de alterações do ritmo da pressão arterial de 24 horas, caracterizada por menor queda pressórica durante o sono.

Diuretics shift circadian rhythm of blood pressure from nondipper to dipper in essential hypertension

BACKGROUND

Recently, we found that sodium restriction shifted the circadian rhythm of blood pressure from nondipper to dipper in patients with the sodium-sensitive essential hypertension. This study examined whether diuretics can transform the circadian rhythm of blood pressure from nondipper to dipper.

METHODS AND RESULTS

We studied 21 patients with essential hypertension during both a baseline period and a period of treatment with hydrochlorothiazide (25 mg daily). The periods lasted 4 weeks each. Twenty-four hour ambulatory blood pressures were measured on the same day of the week at the end of the each period. In nondippers (n=11), but not in dippers (n=10), a significant interaction existed between diuretic therapy and nocturnal fall in systolic and diastolic blood pressure, which indicated that the degree of nocturnal blood pressure fall was affected by diuretic therapy. Nocturnal fall, which was diminished in nondippers, was restored by diuretic therapy with hydrochlorothiazide, indicating that the circadian rhythm of blood pressure shifted from nondipper to dipper patterns.

CONCLUSIONS

The present study demonstrated that diuretics can restore nocturnal blood pressure decline in a manner similar to sodium restriction, which suggests that the kidneys and sodium metabolism may play important roles in the genesis of the circadian rhythm of blood pressure. Diuretic-based treatment may have an additional therapeutic advantage of reducing the risk for cardiovascular complications by transforming the circadian rhythm of blood pressure.

Renal artery stenosis as a cause of renal impairment: implications for treatment of hypertension and congestive heart failure

Images

Insulin resistance and hypertension

Insulin resistance, a common accompaniment of essential hypertension, increases cardiovascular risk both directly, and via its adverse effect on other cardiovascular risk factors. Decreasing insulin resistance by lifestyle modification including diet, weight loss, and physical exercise is an important component of therapy in all patients. With the exception of thiazide diuretics as monotherapy, the currently utilized classes of agent appear equally effective in lowering blood pressure in insulin resistant patients. Currently utilized agents do, however, differ substantially in their effect on insulin resistance and associated risk factors. Agents that diminish insulin resistance may have a rationale in treating insulin resistant patients with hypertension although a decisive recommendation about class of agent in this group of patients must await several prospective large scale trials currently underway. Lower intervention thresholds and lower therapeutic goals would appear to apply to hypertensive patients with insulin resistance especially in the presence of impaired glucose tolerance or overt diabetes mellitus.

Antioxidants for hypertension

Increasing evidence implicates reactive oxygen species in the pathogenesis of hypertension and its cardiovascular complications. By altering the balance in the endothelium between vasoconstrictors such as thromboxane and isoprostanes and vasodilators such as nitric oxide, reactive oxygen species contribute to endothelium-dependent contractions and increased vascular resistance. Antioxidants can restore endothelial function and decrease blood pressure in several models of hypertension and in some, but not all, studies of humans with essential hypertension. The potential of antioxidant therapy for hypertension is considerable.