Showing papers in "Hypertension in 2003"
TL;DR: In those older than age 50, systolic blood pressure of greater than 140 mm Hg is a more important cardiovascular disease (CVD) risk factor than diastolic BP, and hypertension will be controlled only if patients are motivated to stay on their treatment plan.
Abstract: The National High Blood Pressure Education Program presents the complete Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure. Like its predecessors, the purpose is to provide an evidence-based approach to the prevention and management of hypertension. The key messages of this report are these: in those older than age 50, systolic blood pressure (BP) of greater than 140 mm Hg is a more important cardiovascular disease (CVD) risk factor than diastolic BP; beginning at 115/75 mm Hg, CVD risk doubles for each increment of 20/10 mm Hg; those who are normotensive at 55 years of age will have a 90% lifetime risk of developing hypertension; prehypertensive individuals (systolic BP 120-139 mm Hg or diastolic BP 80-89 mm Hg) require health-promoting lifestyle modifications to prevent the progressive rise in blood pressure and CVD; for uncomplicated hypertension, thiazide diuretic should be used in drug treatment for most, either alone or combined with drugs from other classes; this report delineates specific high-risk conditions that are compelling indications for the use of other antihypertensive drug classes (angiotensin-converting enzyme inhibitors, angiotensin-receptor blockers, beta-blockers, calcium channel blockers); two or more antihypertensive medications will be required to achieve goal BP (<140/90 mm Hg, or <130/80 mm Hg) for patients with diabetes and chronic kidney disease; for patients whose BP is more than 20 mm Hg above the systolic BP goal or more than 10 mm Hg above the diastolic BP goal, initiation of therapy using two agents, one of which usually will be a thiazide diuretic, should be considered; regardless of therapy or care, hypertension will be controlled only if patients are motivated to stay on their treatment plan. Positive experiences, trust in the clinician, and empathy improve patient motivation and satisfaction. This report serves as a guide, and the committee continues to recognize that the responsible physician's judgment remains paramount.
14,975 citations
TL;DR: There was a high prevalence of CVD in CKD and that mortality due to CVD was 10 to 30 times higher in dialysis patients than in the general population, and the task force recommended that patients with CKD be considered in the “highest risk group” for subsequent CVD events.
Abstract: Chronic kidney disease1 (CKD) is a worldwide public health problem. In the United States, there is a rising incidence and prevalence of kidney failure, with poor outcomes and high cost. The number of individuals with kidney failure treated by dialysis and transplantation exceeded 320 000 in 1998 and is expected to surpass 650 000 by 2010.1,2 There is an even higher prevalence of earlier stages of CKD (Table 1).1,3 Kidney failure requiring treatment with dialysis or transplantation is the most visible outcome of CKD. However, cardiovascular disease (CVD) is also frequently associated with CKD, which is important because individuals with CKD are more likely to die of CVD than to develop kidney failure,4 CVD in CKD is treatable and potentially preventable, and CKD appears to be a risk factor for CVD. In 1998, the National Kidney Foundation (NKF) Task Force on Cardiovascular Disease in Chronic Renal Disease issued a report emphasizing the high risk of CVD in CKD.5 This report showed that there was a high prevalence of CVD in CKD and that mortality due to CVD was 10 to 30 times higher in dialysis patients than in the general population (Figure 1 and Table 2).6–18 The task force recommended that patients with CKD be considered in the “highest risk group” for subsequent CVD events and that treatment recommendations based on CVD risk stratification should take into account the highest-risk status of patients with CKD.
View this table:
TABLE 1. Stages of CKD
Figure 1. Cardiovascular mortality defined by death due to arrhythmias, cardiomyopathy, cardiac arrest, myocardial infarction, atherosclerotic heart disease, and pulmonary edema in general population (GP; National Center for Health Statistics [NCHS] multiple cause of mortality data files International Classification of Diseases, 9th Revision [ICD 9] codes 402, 404, 410 to 414, and …
1,537 citations
TL;DR: A meta-analysis of randomized controlled trials was performed to estimate the effect of weight reduction on blood pressure overall and in population subgroups, showing that weight loss is important for the prevention and treatment of hypertension.
Abstract: Increased body weight is a strong risk factor for hypertension. A meta-analysis of randomized controlled trials was performed to estimate the effect of weight reduction on blood pressure overall and in population subgroups. Twenty-five randomized, controlled trials (comprising 34 strata) published between 1966 and 2002 with a total of 4874 participants were included. A random-effects model was used to account for heterogeneity among trials. A net weight reduction of −5.1 kg (95% confidence interval [CI], −6.03 to −4.25) by means of energy restriction, increased physical activity, or both reduced systolic blood pressure by −4.44 mm Hg (95% CI, −5.93 to −2.95) and diastolic blood pressure by −3.57 mm Hg (95% CI, −4.88 to −2.25). Blood pressure reductions were −1.05 mm Hg (95% CI, −1.43 to −0.66) systolic and −0.92 mm Hg (95% CI, −1.28 to −0.55) diastolic when expressed per kilogram of weight loss. As expected, significantly larger blood pressure reductions were observed in populations with an average weight loss >5 kg than in populations with less weight loss, both for systolic (−6.63 mm Hg [95% CI, −8.43 to −4.82] vs −2.70 mm Hg [95% CI, −4.59 to −0.81]) and diastolic (−5.12 mm Hg [95% CI, −6.48 to −3.75] vs −2.01 mm Hg [95% CI, −3.47 to −0.54]) blood pressure. The effect on diastolic blood pressure was significantly larger in populations taking antihypertensive drugs than in untreated populations (−5.31 mm Hg [95% CI, −6.64 to −3.99] vs −2.91 mm Hg [95% CI, −3.66 to −2.16]). This meta-analysis clearly shows that weight loss is important for the prevention and treatment of hypertension.
1,244 citations
TL;DR: It is time to reevaluate the role of uric acid as a risk factor for cardiovascular disease and hypertension and to design human studies to address this controversy.
Abstract: Hyperuricemia is associated with hypertension, vascular disease, renal disease, and cardiovascular events. In this report, we review the epidemiologic evidence and potential mechanisms for this association. We also summarize experimental studies that demonstrate that uric acid is not inert but may have both beneficial functions (acting as an antioxidant) as well as detrimental actions (to stimulate vascular smooth muscle cell proliferation and induce endothelial dysfunction). A recently developed experimental model of mild hyperuricemia also provides the first provocative evidence that uric acid may have a pathogenic role in the development of hypertension, vascular disease, and renal disease. Thus, it is time to reevaluate the role of uric acid as a risk factor for cardiovascular disease and hypertension and to design human studies to address this controversy.
1,229 citations
TL;DR: This article showed that reactive oxygen species (ROS) play major roles in the initiation and progression of cardiovascular dysfunction associated with diseases such as hyperlipidemia, diabetes mellitus, hypertension, ischemic heart disease, and chronic heart failure.
Abstract: Accumulating evidence indicates that reactive oxygen species (ROS) play major roles in the initiation and progression of cardiovascular dysfunction associated with diseases such as hyperlipidemia, diabetes mellitus, hypertension, ischemic heart disease, and chronic heart failure. ROS produced by migrating inflammatory cells as well as vascular cells (endothelial cells, vascular smooth muscle cells, and adventitial fibroblasts) have distinct functional effects on each cell type. These include cell growth, apoptosis, migration, inflammatory gene expression, and matrix regulation. ROS, by regulating vascular cell function, can play a central role in normal vascular physiology, and can contribute substantially to the development of vascular disease.
1,021 citations
TL;DR: There are many unanswered questions about the mechanisms of obesity hypertension and renal disease, but this is one of the most promising areas for future research, especially in view of the growing, worldwide "epidemic" of obesity.
Abstract: This paper provides a personal perspective of the role of abnormal renal-pressure natriuresis in the pathogenesis of hypertension. Direct support for a major role of renal-pressure natriuresis in long-term control of arterial pressure and sodium balance comes from studies demonstrating that (1) pressure natriuresis is impaired in all forms of chronic hypertension and (2) prevention of pressure natriuresis from operating, by servo-control of renal perfusion pressure, also prevents the maintenance of sodium balance hypertension. Although the precise mechanisms of impaired pressure natriuresis in essential hypertension have remained elusive, recent evidence suggests that obesity and overweight may play a major role. Obesity increases renal sodium reabsorption and impairs pressure natriuresis by activation of the renin-angiotensin and sympathetic nervous systems and by altered intrarenal physical forces. Chronic obesity also causes marked structural changes in the kidneys that eventually lead to a loss of nephron function, further increases in arterial pressure, and severe renal injury in some cases. Although there are many unanswered questions about the mechanisms of obesity hypertension and renal disease, this is one of the most promising areas for future research, especially in view of the growing, worldwide "epidemic" of obesity.
830 citations
TL;DR: Uric acid regulates critical proinflammatory pathways in VSMCs, suggesting it may have a role in the vascular changes associated with hypertension and vascular disease.
Abstract: Previous studies have reported that uric acid stimulates vascular smooth muscle cell (VSMC) proliferation in vitro. We hypothesized that uric acid may also have direct proinflammatory effects on VSMCs. Crystal- and endotoxin-free uric acid was found to increase VSMC monocyte chemoattractant protein-1 (MCP-1) expression in a time- and dose-dependent manner, peaking at 24 hours. Increased mRNA and protein expression occurred as early as 3 hours after uric acid incubation and was partially dependent on posttranscriptional modification of MCP-1 mRNA. In addition, uric acid activated the transcription factors nuclear factor-κB and activator protein-1, as well as the MAPK signaling molecules ERK p44/42 and p38, and increased cyclooxygenase-2 (COX-2) mRNA expression. Inhibition of p38 (with SB 203580), ERK 44/42 (with UO126 or PD 98059), or COX-2 (with NS398) each significantly suppressed uric acid–induced MCP-1 expression at 24 hours, implicating these pathways in the response to uric acid. The ability of both n-acetyl-cysteine and diphenyleneionium (antioxidants) to inhibit uric acid–induced MCP-1 production suggested involvement of intracellular redox pathways. Uric acid regulates critical proinflammatory pathways in VSMCs, suggesting it may have a role in the vascular changes associated with hypertension and vascular disease.
744 citations
TL;DR: The recommendations of the Working Group are to attempt a clinical trial of antioxidant therapy to prevent preeclampsia and to be complemented by mechanistic research to increase understanding of the genetics and pathogenesis of the disorder.
Abstract: A Working Group on Research in Hypertension in Pregnancy was recently convened by the National Heart, Lung, and Blood Institute to determine the state of knowledge in this area and suggest appropriate directions for research. Hypertensive disorders in pregnancy, especially preeclampsia, are a leading cause of maternal death worldwide and even in developed countries increase perinatal mortality rates 5-fold. Much has been learned about preeclampsia, but gaps in the knowledge necessary to direct therapeutic strategies remain. Oxidative stress is a biologically plausible contributor to the disorder that may be amenable to intervention. Hypertension that antedates pregnancy (chronic hypertension) bears many similarities to hypertension in nonpregnant women, but the special setting of pregnancy demands information to guide evidence-based therapy. The recommendations of the Working Group are to attempt a clinical trial of antioxidant therapy to prevent preeclampsia that is be complemented by mechanistic research to increase understanding of the genetics and pathogenesis of the disorder. For chronic hypertension, clinical trials are recommended to direct choice of drugs, evaluate degree of control, and assess implications to the mother and fetus. Recommendations to increase participation in this research are also presented.
694 citations
TL;DR: Observations suggest that hypoadiponectinemia is associated with impaired endothelium-dependent vasorelaxation and that the measurement of plasma adiponectin level might be helpful as a marker of endothelial dysfunction.
Abstract: Endothelial dysfunction is a crucial feature in the evolution of atherosclerosis. Adiponectin is an adipocyte-specific plasma protein with antiatherogenic and antidiabetic properties. In the present study, we investigated the relation between adiponectin and endothelium-dependent vasodilation. We analyzed endothelial function in 202 hypertensive patients, including those who were not taking any medication. Forearm blood flow was measured by strain-gauge plethysmography. Plasma adiponectin level was highly correlated with the vasodilator response to reactive hyperemia in the total (r=0.257, P<0.001) and no-medication (r=0.296, P=0.026) groups but not with nitroglycerin-induced hyperemia, indicating that adiponectin affected endothelium-dependent vasodilation. Multiple regression analysis of data from all hypertensive patients revealed that plasma adiponectin level was independently correlated with the vasodilator response to reactive hyperemia. Vascular reactivity was also analyzed in aortic rings from adiponectin-knockout (KO) and wild-type (WT) mice. Adiponectin-KO mice showed obesity, hyperglycemia, and hypertension compared with WT mice after 4 weeks on an atherogenic diet. Endothelium-dependent vasodilation in response to acetylcholine was significantly reduced in adiponectin-KO mice compared with WT mice, although no significant difference was observed in endothelium-independent vasodilation in response to sodium nitroprusside. Our observations suggest that hypoadiponectinemia is associated with impaired endothelium-dependent vasorelaxation and that the measurement of plasma adiponectin level might be helpful as a marker of endothelial dysfunction.
589 citations
TL;DR: It is demonstrated that serum uric acid and plasma norepinephrine concentrations predict subsequent weight gain and blood pressure elevation.
Abstract: It has been reported that hypertension and obesity often coexist with hyperuricemia. To clarify the relations between serum uric acid, plasma norepinephrine, and insulin or leptin levels in subjects with weight gain-induced blood pressure elevation, we conducted the present longitudinal study. In 433 young, nonobese, normotensive men, body mass index, blood pressure, and levels of serum uric acid, fasting plasma norepinephrine, insulin, and leptin were measured every year for 5 years. Subjects were stratified by significant weight gain and/or blood pressure elevation (>10% in body mass index or mean blood pressure) for 5 years. At entry, blood pressure, uric acid, and norepinephrine values in subjects with blood pressure elevation were greater than in those without it, although body mass index, insulin, and leptin were similar. At entry, body mass index, blood pressure, uric acid, and norepinephrine in subjects with weight gain were greater than in those without weight gain. The increases in body mass index, mean blood pressure, uric acid, norepinephrine, insulin, and leptin for 5 years were greater in subjects with blood pressure elevation and/or weight gain than in subjects without, and those increases were greatest in subjects with weight gain whose blood pressure was elevated. By multiple regression analysis, basal mean blood pressure, norepinephrine, and uric acid were significant determinant factors of changes in mean blood pressure over 5 years, and basal body mass index, norepinephrine, and uric acid were significant determinant factors of changes in body mass index. These results demonstrate that serum uric acid and plasma norepinephrine concentrations predict subsequent weight gain and blood pressure elevation.
497 citations
TL;DR: Because of the combined effects of endothelial and platelet microparticles on coagulation, leukocytes, and endothelium, it is possible that they may play a pathogenic role in mediating target organ injury in severe hypertension.
Abstract: The molecular mechanisms by which extreme blood pressure elevation leads to vascular injury are not defined. To explore the hypothesis that activation of endothelium and platelets as manifested by increased concentrations of circulating endothelial microparticles and platelet microparticles could play a role in this target organ injury, we conducted a cross-sectional study of these markers in 3 groups: (1) untreated patients referred specifically for treatment of severe uncontrolled hypertension; (2) untreated patients with established mild hypertension; and (3) normotensive volunteer subjects. By ANOVA, endothelial (P=0.002) and platelet (P=0.01) microparticles were greatest in the severely hypertensive group. There was a significant correlation between both of these markers and blood pressure, even in the setting of multiple risk factors. Our results suggest that these markers may be useful and specific for pressure-induced endothelial and platelet activation in hypertension. Furthermore, because of the combined effects of endothelial and platelet microparticles on coagulation, leukocytes, and endothelium, it is possible that they may play a pathogenic role in mediating target organ injury in severe hypertension.
TL;DR: The National High Blood Pressure Education Program (NHBPEP), coordinated by the National Heart, Lung, and Blood Institute (NHLBI), has released its long-awaited Joint National Committee (JNC) 7 report.
Abstract: The National High Blood Pressure Education Program (NHBPEP), coordinated by the National Heart, Lung, and Blood Institute (NHLBI), has released its long-awaited Joint National Committee (JNC) 7 report.1 The report will be made available in 2 forms: the “Express” or short version and a longer version that will be published in Hypertension and will provide more detail regarding the recommendations. On its surface, it resembles the 6 predecessors, but to fully appreciate this new landmark document, one must recognize the process and context from which it is derived and what it is about to do.
You cannot direct the winds; you can adjust the sails.
Approximately 35 years ago, clinicians were busy managing severe and malignant hypertension. Hospitals filled their beds with stroke patients and stroke wards were commonplace. Coronary heart disease and stroke prevalence and accompanying mortality rates were the highest ever recorded. During the next generation, different classes of antihypertensive agents were developed and tested in a variety of settings and among different patients. The studies independently and collectively contributed to a universal finding: lowering arterial pressure can remarkably reduce cardiovascular morbidity and mortality rates as well as slow the progression of renal disease, retinopathy, and all-cause deaths. When these findings first became available, the NHLBI formed the NHBPEP, designed to translate this information through public and professional education programs. …
TL;DR: It is concluded that serum Uric acid is directly correlated with blood pressure in untreated children and that a serum uric acid value >5.5 mg/dL in an adolescent being evaluated for hypertension strongly suggests primary hypertension as opposed to white-coat or secondary hypertension.
Abstract: Experimental animal models suggest that uric acid might have a pathogenic role in the early development of primary hypertension. We hypothesized that serum uric acid is correlated with blood pressure in children with new-onset, untreated, primary hypertension. We evaluated 125 consecutive children referred to the Baylor Pediatric Renal Program for evaluation of hypertension. None of the subjects had previously been evaluated or treated for hypertension. The children ranged in age from 6 to 18 years (mean, 13.4+/-3.3) and had normal renal function (creatinine clearance >80 mL x min(-1) x 1.73 m(-2)). Sixty-three children had primary hypertension, 40 had secondary hypertension, and 22 had white-coat hypertension. Forty controls with normal blood pressure were recruited from the renal clinic. Uric acid levels were directly correlated with systolic (r=0.80, P=0.0002) and diastolic (r=0.66, P=0.0006) blood pressure in controls and in subjects with primary hypertension and were independent of renal function. Serum uric acid concentrations >5.5 mg/dL were found in 89% of subjects with primary hypertension, in 30% with secondary hypertension, in 0% with white-coat hypertension, and in 0% of controls. We conclude that serum uric acid is directly correlated with blood pressure in untreated children and that a serum uric acid value >5.5 mg/dL in an adolescent being evaluated for hypertension strongly suggests primary hypertension as opposed to white-coat or secondary hypertension. These results are consistent with the hypothesis that uric acid might have a role in the early pathogenesis of primary hypertension.
TL;DR: It is suggested that hypoadiponectinemia is related to insulin resistance in essential hypertension and that RAS blockade increases adiponectin concentrations with improvement in insulin sensitivity.
Abstract: Adiponectin, an adipocyte-derived protein, has been suggested to play an important role in insulin sensitivity. We examined the association between insulin sensitivity (M value) evaluated by the euglycemic-hyperinsulinemic glucose clamp and adiponectin concentrations in 30 essential hypertensives (EHT) and 20 normotensives (NT) and investigated the effect of blockade of the renin-angiotensin system (RAS) on adiponectin concentrations. EHT were divided into 12 insulin-resistant EHT (EHT-R) and 18 non-insulin-resistant EHT (EHT-N) using mean 1S D of the M value in NT. There were no intergroup differences in age, gender, and body mass index (BMI). EHT-R had significantly higher levels of insulin and triglyceride and lower levels of adiponectin than did NT and EHT-N. EHT-R had higher levels of free fatty acid and lower levels of high-density lipoprotein (HDL) cholesterol than did EHT-N. Adiponectin concentrations were positively correlated with M value and HDL cholesterol and negatively correlated with BMI, insulin, free fatty acid, and triglyceride but not with blood pressure. M value, BMI, and HDL cholesterol were independent determinants of adiponectin concentrations in multiple and stepwise regression analyses. Sixteen EHT were treated with an angiotensin-converting enzyme inhibitor (temocapril, 4 mg/d; n9) or an angiotensin II receptor blocker (candesartan, 8 mg/d; n7) for 2 weeks. Treatment with temocapril or candesartan significantly decreased blood pressure and increased M value and adiponectin concentrations but did not affect BMI and HDL cholesterol. These results suggest that hypoadiponectinemia is related to insulin resistance in essential hypertension and that RAS blockade increases adiponectin concentrations with improvement in insulin sensitivity. (Hypertension. 2003;42:76-81.)
TL;DR: Investigating the temporal sequence linking hypertension, blood pressure, and heart rate variability in a population-based cohort of 11 061 individuals aged 45 to 54 years at baseline supports the thesis that the autonomic nervous system is involved in the development of hypertension, yet suggests that differences in the autonomics profile of hypertensives and normotensives do not increase with time.
Abstract: Dysregulation of the autonomic nervous system has been implicated in the development of hypertension. Heart rate variability is a noninvasive tool to quantitatively estimate cardiac autonomic activity and has been used to document decreased cardiac autonomic activity in hypertension. The ability of decreased heart rate variability to predict incident hypertension has not been well studied, and there are no studies of whether hypertension leads to changes in heart rate variability. We investigated the temporal sequence linking hypertension, blood pressure, and heart rate variability in a population-based cohort of 11 061 individuals aged 45 to 54 years at baseline. Individuals with hypertension had decreased heart rate variability at baseline, and this association was present across the full blood pressure range. Among 7099 individuals without hypertension at baseline, low heart rate variability predicted greater risk of incident hypertension over 9 years of follow-up. The hazard ratio (95% confidence interval (CI)) for the lowest compared with the highest quartile of the standard deviation of normal-to-normal R-R intervals was 1.24 (95% CI, 1.10 -1.40), for the root mean square of successive differences in normal-to-normal R-R intervals was 1.36 (95% CI, 1.21-1.54), and for R-R interval was 1.44 (95% CI, 1.27-1.63). Over 9 years, there was no measurable difference in the rate of change in heart rate variability among those with and without hypertension, although the differences in heart rate variability at follow-up were smaller than those at baseline. These findings thus support the thesis that the autonomic nervous system is involved in the development of hypertension, yet suggest that differences in the autonomic profile of hypertensives and normotensives do not increase with time. (Hypertension. 2003;42:1106-1111.)
TL;DR: The coexistence of OSA and obesity may have more widespread implications for cardiovascular control and dysfunction in obese individuals and may contribute to some of the clustering of abnormalities broadly defined as the metabolic syndrome.
Abstract: Obesity has a high and rising prevalence and represents a major public health problem. Obstructive sleep apnea (OSA) is also common, affecting an estimated 15 million Americans, with a prevalence that is probably also rising as a consequence of increasing obesity. Epidemiologic data support a link between obesity and hypertension as well as between OSA and hypertension. For example, untreated OSA predisposes to an increased risk of new hypertension, and treatment of OSA lowers blood pressure, even during the daytime. Possible mechanisms whereby OSA may contribute to hypertension in obese individuals include sympathetic activation, hyperleptinemia, insulin resistance, elevated angiotensin II and aldosterone levels, oxidative and inflammatory stress, endothelial dysfunction, impaired baroreflex function, and perhaps by effects on renal function. The coexistence of OSA and obesity may have more widespread implications for cardiovascular control and dysfunction in obese individuals and may contribute to some of the clustering of abnormalities broadly defined as the metabolic syndrome. From the clinical and therapeutic perspectives, the presence of resistant hypertension and the absence of a nocturnal decrease in blood pressure in obese individuals should prompt the clinician to consider the diagnosis of OSA, especially if clinical symptoms suggestive of OSA (such as poor sleep quality, witnessed apnea, excessive daytime somnolence, and so forth) are also present.
TL;DR: A high frequency of PA is found in essential hypertensives classified in stages 2 and 3 according to the JNC VI, and the low frequency of computed tomography scan abnormalities and hypokalemia suggests that the diagnosis for most PA patients corresponds to attenuated forms of the disease.
Abstract: Recent studies in hypertensive populations that have used the serum aldosterone (SA) to plasma renin activity (PRA) ratio as a screening test have demonstrated a high prevalence of primary aldosteronism (PA). This frequency is higher than that previously described when hypokalemia was used as a screening tool. However, other factors, such as the characteristics of hypertensive disease, could also influence the prevalence of PA. We studied 609 essential hypertensive patients, classified according to the Joint National Committee VI (JNC VI), in 3 different stages depending on the severity of their hypertensive disease. We measured SA and PRA and calculated the SA-PRA ratio for all patients. An SA-PRA ratio >25 was detected in 63 of 609 patients, and the fludrocortisone test confirmed the PA diagnoses in 37 of 609 (6.1%) cases. PA prevalence according to hypertension stage was as follows: stage 1, 6 of 301 cases (1.99%); stage 2, 15 of 187 cases (8.02%); and stage 3, 16 of 121 cases (13.2%). PA patients were slightly younger than the other hypertensive patients (48.4+/-10.5 vs 53.6+/-10.2 years; P<0.05). Serum potassium levels were normal in 36 of 37 PA patients; only 1 patient had minor hypokalemia. Computed tomography scans showed bilateral adrenal enlargement in 7 and an adrenal nodule in 2 cases. In summary, we found a high frequency of PA in essential hypertensives classified in stages 2 and 3 according to the JNC VI. The low frequency of computed tomography scan abnormalities and hypokalemia suggests that the diagnosis for most PA patients corresponds to attenuated forms of the disease.
TL;DR: The possibility that aldosterone blockade may represent optimal therapy for patients with early diabetic nephropathy who show ald testosterone escape during ACE inhibitor treatment and who no longer show maximal antiproteinuric effects of ACE inhibition is suggested.
Abstract: It has been reported that continuous ACE inhibitor therapy does not necessarily produce a maintained decrease in plasma aldosterone levels, which may remain high or increase eventually during long-term use (aldosterone escape). We have examined the role of aldosterone escape in 45 patients with type 2 diabetes and early nephropathy treated with an ACE inhibitor for 40 weeks. With treatment, there was a 40% reduction in average urinary albumin excretion, although urinary albumin excretion in patients with aldosterone escape (18 patients) was significantly higher than that in patients without escape (27 patients). In the 18 patients with escape, spironolactone (25 mg/d) was added to ACE inhibitor treatment in 13. After a 24-week study period, urinary albumin excretion and left ventricular mass index were significantly reduced without blood pressure change. In conclusion, the present study demonstrates that aldosterone escape is observed in 40% of patients with type 2 diabetes with early nephropathy despite the use of ACE inhibitors. Our study suggests the possibility that aldosterone blockade may represent optimal therapy for patients with early diabetic nephropathy who show aldosterone escape during ACE inhibitor treatment and who no longer show maximal antiproteinuric effects of ACE inhibition. Additional, larger, prospectively randomized, double-blind studies will be needed before adaptation of this strategy.
TL;DR: Higher aortic systolic blood pressure and greater arterial stiffness, in part due to reduced pulse pressure amplification and increased arterial wave reflection, suggest that the adverse hemodynamic effects have hitherto been underestimated in young chronic smokers.
Abstract: The brachial artery pressure waveform is abnormal in smokers, but the effect of smoking on the aortic pressure waveform in both smokers and nonsmokers, particularly in the younger population, is unknown. We compared the acute and chronic effects of smoking on large-artery properties in 185 healthy young smokers and nonsmokers (mean+/-SD, 22+/-5 years). We matched 41 chronic smokers for age, height, weight, and gender with 116 nonsmokers. The augmentation index, a measure of arterial wave reflection in the aorta, was measured by applanation tonometry (Sphygmocor). We also compared augmentation index, aortic pulse wave velocity (Complior), and blood pressure in 28 subjects (11 chronic smokers) before and for 15 minutes after smoking 1 cigarette (nicotine content, 1.2 mg). Although brachial blood pressure was not different, the aortic systolic blood pressure (101+/-8 versus 97+/-9 mm Hg) and augmentation index (0.7+/-13 versus -5.7+/-14) were higher (P<0.01) in chronic smokers than in nonsmokers, whereas aortic-brachial pulse pressure amplification was reduced (13.7+/-8 versus 17.7+/-5 mm Hg, P<0.01). These effects were seen in both male and female subjects. Acutely in both groups, smoking significantly increased (P<0.01) both brachial and aortic blood pressure, augmentation index, and pulse wave velocity. No changes were seen after sham smoking. This study shows an acute increase in arterial stiffness after smoking 1 cigarette in chronic smokers and nonsmokers. Higher aortic systolic blood pressure and greater arterial stiffness, in part due to reduced pulse pressure amplification and increased arterial wave reflection, suggest that the adverse hemodynamic effects have hitherto been underestimated in young chronic smokers.
TL;DR: In whole blood and in mononuclear cells from hypertensive subjects, there was an increase in oxidative stress and a reduction in the activity of antioxidant mechanisms that appeared to be independent of the blood pressure values.
Abstract: The objective was to study oxidative status, antioxidant activities, and reactive oxygen species byproducts in whole blood and mononuclear peripherals cells and their relationship with blood pressu...
TL;DR: Excess body weight is associated with higher aortic stiffness in whites and African Americans as young as 20 to 30 years, and the prevalence of obesity among the young warn of substantially increased cardiovascular disease incidence as this cohort ages.
Abstract: Obesity has reached epidemic levels and carries a risk for cardiovascular disease. Obesity's effects on the vascular systems of young adults and African Americans have not been well characterized. The aim of this study was to assess the association between measures of obesity and aortic stiffness in 186 young adults (20 to 40 years, 50% African American) and 177 older adults (41 to 70 years, 33% African American). Aortic stiffness was measured by aortic pulse-wave velocity. The median pulse-wave velocity value was 468 cm/s for young adults and 627 cm/s for older adults (P 30) had a mean pulse-wave velocity value 47 cm/s higher than did nonobese individuals (P<0.001). Obesity measures were among the strongest independent predictors of pulse-wave velocity overall and for both age groups. Results were consistent by race. In conclusion, excess body weight is associated with higher aortic stiffness in whites and African Americans as young as 20 to 30 years. The strength of the association, the early age at which it appears, and the prevalence of obesity among the young warn of substantially increased cardiovascular disease incidence as this cohort ages.
TL;DR: A meta-analysis of longer-term trials looked at the dose response between salt reduction and fall in blood pressure and compared this with 2 well-controlled studies of 3 different salt intakes, finding a consistent dose response to salt reduction within the range of 12 to 3 g/d.
Abstract: The current public health recommendations are to reduce salt intake from 9 to 12 g/d to 5 to 6 g/d. However, these values are based on what is feasible rather than the maximum effect of salt reduct...
TL;DR: With the development of dual alpha/gamma-PPAR activators, these newer agents may become interesting therapeutic agents for prevention of vascular and cardiac complications of hypertension as well as for preventative therapy in other forms of cardiovascular disease.
Abstract: Peroxisome proliferator-activated receptors (PPAR) are nuclear receptors acting as transcription factors on numerous target genes after heterodimerization with the retinoid X receptor. PPAR-α and PPAR-γ may be activated by different agonists, although the endogenous ligands are unknown. Although PPAR-α is mainly involved in fatty acid oxidation and expressed in liver, kidney, and skeletal muscle, and PPAR-γ is mainly involved in fat cell differentiation and insulin sensitivity, both are expressed in smooth muscle cells and myocardium, although PPAR-γ are scarce in the latter. Activators of PPAR-α such as fatty acids and fibrates, and PPAR-γ such as thiazolidinediones have been shown to exert antiproliferative effects, antagonize angiotensin II actions in vivo and in vitro, and exert antioxidant actions inhibiting generation of reactive oxygen species and activation of inflammatory mediators on blood vessels and the heart. These agents lowered blood pressure in several models of hypertension and corrected endothelial dysfunction. They exerted anti-inflammatory and antifibrotic actions on blood vessels and the heart. With the development of dual α/γ-PPAR activators, these newer agents may become interesting therapeutic agents for prevention of vascular and cardiac complications of hypertension as well as for preventative therapy in other forms of cardiovascular disease.
TL;DR: This article provides a chronological perspective on the development of knowledge concerning the neural control of renal function and is divided into three parts: the past, the present, and the future.
Abstract: This article provides a chronological perspective on the development of knowledge concerning the neural control of renal function and is divided into three parts: the past, the present, and the future.
TL;DR: Feeding a diet rich in lard to pregnant rats leads to gender-related cardiovascular dysfunction in normally fed offspring, andothelium-dependent relaxation to acetylcholine was blunted in male and female offspring of lard-fed dams.
Abstract: Epidemiological studies suggest an association between maternal nutrition and offspring cardiovascular disease. We previously demonstrated endothelial dysfunction and abnormal aortic fatty acid composition in adult female offspring of rats fed animal lard during pregnancy. We have now further investigated this model. Female Sprague-Dawley rats were fed a control breeding diet (5.3% fat) or a diet rich in lard (25.7% fat) 10 days before and throughout pregnancy and lactation. Male and female offspring were implanted with radiotelemeters for recording of blood pressure, heart rate, and activity at 80, 180, and 360 days of age. Reactivity to acetylcholine and to nitric oxide were assessed in isolated small mesenteric arteries from 80- and 180-day-old littermates. Systolic blood pressure (awake phase) was raised in female offspring (180 days: offspring of control, 130.7±1.6 mm Hg, n=5, versus offspring of lard-fed, 138.1±2.9, n=5, P=0.029; 360 days: offspring of control, 129.7±3.7 mm Hg, n=6, versus offspring of lard-fed, 142.1±3.2, n=6, P=0.005). Diastolic blood pressure was also raised at 180 days (offspring of control, 87.6±1.0 mm Hg, n=5, versus offspring of lard-fed, 94.7±2.6, n=5, P=0.011). Blood pressure was not raised in male offspring. Endothelium-dependent relaxation to acetylcholine was blunted in male and female offspring of lard-fed dams (80 and 180 days). Feeding a diet rich in lard to pregnant rats leads to gender-related cardiovascular dysfunction in normally fed offspring.
TL;DR: It is suggested that regular physical activity, particularly when performed during the year before pregnancy and during early pregnancy, is associated with a reduced risk of preeclampsia.
Abstract: The potential benefits and risks of physical activity before and during pregnancy are not well studied. We studied the relation between recreational physical activity and the risk of preeclampsia in a case-control study of 201 preeclamptic and 383 normotensive pregnant women. Participants provided information about the type, intensity, frequency, and duration of physical activity performed during the first 20 weeks of pregnancy and during the year before pregnancy. Women who engaged in any regular physical activity during early pregnancy, compared with inactive women, experienced a 35% reduced risk of preeclampsia (odds ratio, 0.65; 95% confidence interval [CI], 0.43 to 0.99). Compared with inactive women, those engaged in light or moderate activities (ie, activities with metabolic-equivalent scores or =6) was 54% (95% CI, 0.27 to 0.79). Brisk walking (average walking pace > or =3 mi/h), when compared with no walking at all, was associated with a 30% to 33% reduction in preeclampsia risk. Stair climbing was inversely associated with the risk of preeclampsia (P for trend=0.039). Recreational physical activity performed during the year before pregnancy was associated with similar reductions in preeclampsia risk. These data suggest that regular physical activity, particularly when performed during the year before pregnancy and during early pregnancy, is associated with a reduced risk of preeclampsia.
TL;DR: It is demonstrated that aliskiren, through inhibition of renin, is an effective and safe orally active BP-lowering agent and well tolerated at all doses studied.
Abstract: Inhibition of the first and rate-limiting step of the renin-angiotensin system has long been an elusive therapeutic goal. Aliskiren, the first known representative of a new class of completely nonpeptide, orally active, renin inhibitors, has been shown to inhibit the production of angiotensin I and II in healthy volunteers and to reduce blood pressure (BP) in sodium-depleted marmosets. The aim of this randomized, double-blind, active comparator trial study was to assess the BP-lowering efficacy and safety of aliskiren. Two hundred twenty-six patients, 21 to 70 years of age, with mild to moderate hypertension, were randomly assigned to receive 37.5 mg, 75 mg, 150 mg, or 300 mg aliskiren or 100 mg losartan daily for 4 weeks. Dose-dependent reductions in daytime ambulatory systolic pressure (mean change, mm Hg [SD of change]; -0.4 [11.7], -5.3 [11.3], -8.0 [11.0], and -11.0 [11.0], P=0.0002) and in plasma renin activity (median change % [interquartile range]; -55 [-64, -11], -60 [-82, -46], -77 [-86, -72], and -83 [-92, -71], P=0.0008) were observed with 37.5, 75, 150, and 300 mg aliskiren. The change in daytime systolic pressure with 100 mg losartan (-10.9 [13.8]) was not significantly different from the changes seen with 75, 150, and 300 mg aliskiren. Aliskiren was well tolerated at all doses studied. This study demonstrates that aliskiren, through inhibition of renin, is an effective and safe orally active BP-lowering agent. Whether renin inhibition results in protection from heart attack, stroke, and nephropathy, similar to angiotensin-converting enzyme inhibition and angiotensin receptor blockade, needs to be researched.
TL;DR: In patients with essential hypertension, ACE inhibitors appear to be the only compounds able to improve conduit artery endothelium‐dependent vasodilation and oxidative stress and increased plasma antioxidant capacity.
Abstract: To compare the effect of antihypertensive drugs on endothelium-dependent vasodilation in the peripheral conduit arteries of patients with essential hypertension, in a prospective, randomized, parallel group study, endothelial function was assessed in 168 hypertensive patients before and after 6-month treatment with randomly assigned nifedipine GITS (30 to 60 mg, n=28), amlodipine (5 to 10 mg, n=28), atenolol (50 to 100 mg, n=29), nebivolol (5 to 10 mg, n=28), telmisartan (80 to 160 mg, n=29), and perindopril (2 to 4 mg, n=28). If necessary, hydrochlorothiazide (25 mg) was added to each compound. We evaluated brachial artery flow-mediated, endothelium-dependent dilation (high-resolution ultrasound) compared with endothelium-independent response to glyceryl trinitrate (25 microg/s). Brachial artery diameter was measured by automatic computerized analysis. Forty healthy subjects were evaluated as a control group. Oxidative stress production was evaluated by measuring plasma malondialdehyde and plasma lipoperoxides; plasma antioxidant capacity was assessed as ferric-reducing antioxidant power. Hypertensive patients showed a significantly (P<0.01) lower flow-mediated dilation (5.2+/-1.9%) as compared with healthy control subjects (7.1+/-2.6%). Response to glyceryl trinitrate was similar in control subjects and patients. At baseline, blood pressure, diameter, flow-mediated dilation, and response to glyceryl trinitrate were similar in the different treatment groups. All treatments similarly reduced blood pressure, but only perindopril increased flow mediated dilation (from 5.1+/-2 to 6.4+/-2.4%; P<0.01) without modifying the response to glyceryl trinitrate. Perindopril but also telmisartan nifedipine and amlodipine reduced oxidative stress and increased plasma antioxidant capacity. In patients with essential hypertension, ACE inhibitors appear to be the only compounds able to improve conduit artery endothelium-dependent vasodilation.
TL;DR: The identification of ACE2 in the kidney, its modulation in diabetes, and the recent description that this enzyme plays a biological role in the generation and degradation of various angiotensin peptides provides a rationale to further explore the role of this enzyme in various pathophysiological states including diabetic complications.
Abstract: ACE2, initially cloned from a human heart, is a recently described homologue of angiotensin-converting enzyme (ACE) but contains only a single enzymatic site that catalyzes the cleavage of angiotensin I to angiotensin 1-9 [Ang(1-9)] and is not inhibited by classic ACE inhibitors. It also converts angiotensin II to Ang(1-7). Although the role of ACE2 in the regulation of the renin-angiotensin system is not known, the renin-angiotensin system has been implicated in the pathogenesis of diabetic complications and in particular in diabetic nephropathy. Therefore, the aim of this study was to assess the possible involvement of this new enzyme in the kidney from diabetic Sprague-Dawley rats to compare and contrast it to ACE. ACE2 and ACE gene and protein expression were measured in the kidney after 24 weeks of streptozocin diabetes. ACE2 and ACE mRNA levels were decreased in diabetic renal tubules by approximately 50% and were not influenced by ACE inhibitor treatment with ramipril. By immunostaining, both ACE2 and ACE protein were localized predominantly to renal tubules. In the diabetic kidney, there was reduced ACE2 protein expression that was prevented by ACE inhibitor therapy. The identification of ACE2 in the kidney, its modulation in diabetes, and the recent description that this enzyme plays a biological role in the generation and degradation of various angiotensin peptides provides a rationale to further explore the role of this enzyme in various pathophysiological states including diabetic complications.
TL;DR: Control of blood pressure within normal levels should be stressed as a strategy to prevent end‐stage renal disease in both men and women.
Abstract: Blood pressure as a risk factor for development of end-stage renal disease has not been fully studied, particularly in women. We studied the development of end-stage renal disease from 1983 through 2000 in 98 759 subjects, 46 881 men and 51 878 women, 20 to 98 years of age, who were screened in 1983 in Okinawa, Japan. Data for all dialysis patients registered from 1983 to 2000 in Okinawa were used to identify the screened subjects in whom end-stage renal disease developed. In follow-up, 400 subjects, 231 men and 169 women, had end-stage renal disease. Age, body mass index, and adjusted relative risk for systolic and diastolic blood pressure for both men and women were measured. When these results were compared with an optimal blood pressure, the relative risk of development of end-stage renal disease for those with high-normal blood pressure and hypertension were significant in both men and women. Hypertension is a significant risk factor for development of end-stage renal disease not only in men but also in women. Control of blood pressure within normal levels should be stressed as a strategy to prevent end-stage renal disease in both men and women.