Aging, arterial stiffness, and hypertension.

See related article, pp 384–390 There is an ever expanding literature base implicating T lymphocytes in the development and progression of numerous cardiovascular diseases, including hypertension. T lymphocytes contribute to the development of hypertension in genetic, angiotensin II (Ang-II), and salt-sensitive male experimental animals.1 Among the most definitive studies implicating T lymphocytes in hypertension are studies conducted in Rag-1−/− mice, which lack B and T lymphocytes. Guzik et al2 were the first to demonstrate that these mice have a blunted hypertensive response to Ang-II infusion. Adoptive transfer of T lymphocytes into male Rag−/− mice restored the hypertensive response to Ang-II; adoptive transfer of B lymphocytes did not alter the blood pressure (BP) response. Although low-grade inflammation, and T lymphocytes in particular, are now a recognized hallmark of hypertension, the majority of basic science literature in this field has been conducted exclusively in males, despite the fact that females account for ≈50% of all hypertensive cases in the United States. Therefore, it was with great interest that we read the study by Pollow et al3 in the current issue of Hypertension , which was designed to determine (1) whether there are sex differences in the ability of T lymphocytes to induce Ang-II–dependent hypertension and (2) whether sex affects central or renal T lymphocytes infiltration after Ang-II hypertension. Of particular interest, they found that male mice exhibited a significant increase in BP and renal damage to Ang-II after the adoptive transfer of CD3+ T lymphocytes from wild-type male mice. In contrast, BP responses and renal injury to Ang-II were not significantly altered in female Rag−/− mice after adoptive transfer of T lymphocytes from males. Male Rag−/− mice also had greater renal CD3+, CD4+, CD8+, and T-regulatory cells (Tregs) …

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Increasing adiposity with a clinical endpoint of obesity is associated with a progressive increase in risk of cardiovascular diseases (CVD). However, we are only beginning to understand the physiological and pathophysiological mechanisms by which excessive body fat storage causes CVD. In this issue of Hypertension , the findings of Wildman et al1 extend and strengthen previous observations2–5 by showing that changes in arterial stiffness, as measured by aortic pulse-wave velocity (PWV), are related to changes in body weight over a 2-year follow-up period in healthy men and women aged 20 to 40 years. Weight gain was associated with an increase, whereas weight loss was associated with a decrease in aortic PWV, independent of changes in blood pressure. The greatest increases in aortic PWV were observed in those subjects who gained the most weight (≥4.5 kg). Importantly, the changes in aortic PWV were related to changes in body mass index (BMI), indicating that the associations with body weight were mediated by changes in adiposity (rather than fat-free mass). Changes in aortic PWV over time also were related to baseline body weight, BMI, and waist circumference (an indirect measure of abdominal adiposity), providing evidence that higher initial levels of total and abdominal body fatness are associated with greater future increases in arterial stiffness. The study included subjects with a broad range of BMI, suggesting that the findings are applicable to both nonobese and obese adults in the general population. An important finding was that black adults demonstrated greater increases in weight gain-adjusted and blood pressure-adjusted aortic PWV over time, suggesting that they undergo greater increases in arterial stiffness in response to the same age-associated weight gain compared with whites. These observations provide further support for the emerging concept that adiposity-driven weight gain during adulthood contributes significantly to the adverse changes …

Hypertension is a public health challenge of increasing importance because of its high frequency and concomitant risk of cardiovascular and renal disease. It has been estimated that the worldwide prevalence of hypertension was 972 million in 2000, and this number will increase by 60% by the year 2025.1 A large body of evidence indicates that the increasing prevalence of hypertension is sustained by the escalation of overweight and obesity. Actually, most hypertensive patients are also overweight or obese,2 and this may contribute to further deteriorate their cardiovascular risk profile. Similar to hypertension, obesity is independently associated with numerous adverse cardiovascular outcomes, and, most importantly, adipose tissue expansion and hypertension have a synergistic negative impact on cardiovascular prognosis. Hence, the hypertension–obesity pandemic imposes today a considerable burden on societies and healthcare systems that one can reasonably expect to increase further in the next years. The importance of preventing hypertension underscores the critical role of a better understanding of the most common mechanisms underlying its development. The association between obesity and hypertension has been recognized for many decades,2 and an almost linear relation appears between body mass index and systolic and diastolic blood pressures, at least over a body mass index range from 16 to 31 kg/m2.3 Also, risk estimates from the Framingham Heart Study suggest that ≈78% of the hypertension cases in men and 65% in women can be directly attributed to obesity.4 Further evidence for a consistent link between adiposity and hypertension comes from studies showing that weight gain is almost invariably associated with an increase in blood pressure. The increase in blood pressure is closely related to the magnitude of weight gain, and even moderate weight gain is associated with an increased risk of developing hypertension.5 In addition, even modest weight …

Predictors of Significant Short-Term Increases in Blood Pressure in a Community-Based Population

Clinica Medica, Universita` Milano-Bicocca,Ospedale San Gerardo, Monza (Milano) and Centro di Fisiologia Clinica eIpertensione, Universita` di Milano, Milan, Italy.Correspondence and requests for reprints to Professor Arya M. Sharma,Franz-Volhard-Klinik, Charite´, Campus Berlin-Buch, Wiltbergstrasse 50,13125 Berlin, Federal Republic of Germany.Tel: ⁄49 30 941 72203; fax: ⁄49 30 941 72206; e-mail: sharma@fvk-berlin.de

Obesity prevalence is soaring in industrialized countries and progressively increasing in the developing world. Altered patterns of nutrition and reduction in work-related energy expenditure have led to obesity becoming a truly global health issue. The central thermodynamic formulation for the origins of obesity, a mismatched energy balance equation, with an excess of dietary calorie intake over body energy expenditure, is a first step in the understanding of this phenomenon but leaves the diverse causal issues unexplored. Dietary calorie intake is modified by multiple social, economic, and cultural issues. Similarly, the reduction in energy expenditure in recent decades has complex origins, deriving from demographic and social change, which includes third-world transition from a labor-intensive agricultural economy to an industrial base, the introduction of household labor-saving devices, the popularity of transportation modes not reliant on physical effort, and from changed recreational habits, particularly in childhood (computer games instead of physical games). The prevalence of childhood obesity is escalating, having whimsically but not entirely unrealistically been attributed to “potato chips and computer chips.” Obesity and hypertension are intimately associated, and both very commonly coexist in individual patients with insulin resistance, hyperinsulinemia, and hyperlipidemia, this clustering of adverse health factors1 being designated the metabolic syndrome. The pathophysiological mechanisms by which obesity leads to hypertension remain uncertain. Understanding these processes might, perhaps, provide a more rational basis for drug treatment of obesity-related hypertension. Attempts at reduction in body weight, although pivotal in the treatment of obesity-related hypertension, more often than not fail, so that antihypertensive drug therapy is often needed. This review analyses the proposition that obesity is characterized by activation of the sympathetic nervous system and that obesity-related hypertension is, in fact, neurogenic, being initiated and sustained by neural mechanisms. At one time, this idea would have been held to fly in the …

The clinical presentation of autonomic failure is orthostatic hypotension. Severely affected patients require pharmacological treatment to prevent presyncopal symptoms or frank syncope. We previously reported in a proof of concept study that pediatric doses of the norepinephrine transporter blockade, atomoxetine, increases blood pressure in autonomic failure patients with residual sympathetic activity compared with placebo. Given that the sympathetic nervous system is maximally activated in the upright position, we hypothesized that atomoxetine would be superior to midodrine, a direct vasoconstrictor, in improving upright blood pressure and orthostatic hypotension-related symptoms. To test this hypothesis, we compared the effect of acute atomoxetine versus midodrine on upright systolic blood pressure and orthostatic symptom scores in 65 patients with severe autonomic failure. There were no differences in seated systolic blood pressure (means difference=0.3 mm Hg; 95% confidence interval, -7.3 to 7.9; P=0.94). In contrast, atomoxetine produced a greater pressor response in upright systolic blood pressure (means difference=7.5 mm Hg; 95% confidence interval, 0.6-15; P=0.03) compared with midodrine. Furthermore, atomoxetine (means difference=0.4; 95% confidence interval, 0.1-0.8; P=0.02), but not midodrine (means difference=0.5; 95% confidence interval, -0.1 to 1.0; P=0.08), improved orthostatic hypotension-related symptoms as compared with placebo. The results of our study suggest that atomoxetine could be a superior therapeutic option than midodrine for the treatment of orthostatic hypotension in autonomic failure.

<i>Hypertension</i> Editors’ Picks

<i>Hypertension</i> Editors’ Picks

VEGF (vascular endothelial growth factor) receptor tyrosine kinase inhibitors have become first-line therapy for metastatic renal cell carcinoma. Their use commonly leads to hypertension, but their effects on long-term renal function are not known. In addition, it has been suggested that the development of hypertension is linked to treatment efficacy. The objective of this study was to determine the effects of these drugs on long-term renal function, especially in those with renal dysfunction at baseline, and to examine the role of hypertension on these effects. Serum creatinine measurements were used to calculate the estimated glomerular filtration rate for 130 renal cell carcinoma patients who were treated with this class of tyrosine kinase inhibitors. New or worsening hypertension was defined by documented start or addition of antihypertensive medications. Overall, the use of tyrosine kinase inhibitors in patients with estimated glomerular filtration <60 or 60 mL/minute per 1.73 m 2 was not associated with a decline in long-term renal function. During follow-up, 41 patients developed new or worsening hypertension within 30 days from first drug administration, and this was not linked to further reductions in glomerular filtration. These patients seemed to survive longer than those who did not develop hypertension within 30 days, although this was not statistically significant (P=0.07). Our findings suggest that the use of VEGF tyrosine kinase inhibitors does not adversely affect long-term renal function even in the setting of new-onset hypertension or reduced renal function at baseline.

Changes in noradrenaline sensitivity and morphology of arterial resistance vessels during development of high blood pressure in spontaneously hypertensive rats.

It has been conventional wisdom for some time now that nonsteroidal antiinflammatory drugs (NSAIDs), whether selective for inhibition of cyclooxygenase 2 (COX-2) or nonselective, increase blood pressure (BP) or interfere with BP control and that acetaminophen should not have this effect.1,–,4 Controlled clinical trials have shown that NSAIDs have heterogeneous effects on clinic and 24-hour BP in normotensive and hypertensive subjects.3 The inhibition of COX-2 by NSAIDs results in decreased actions of both vasodilatory and natriuretic prostaglandins.3 In most individuals, homeostasis of plasma volume is reestablished by small, nearly undetectable increases in BP,5 whereas in patients with impaired excretory function, more substantial volume retention occurs that may be associated with hypertension, edema, and congestive heart failure.3,5 Article see p1789 Before 2002, little was known about the effects of NSAIDs on 24-hour BP in patients with arthritis who also had hypertension and/or vascular diseases.6,–,8 Because ambulatory BP has improved reproducibility compared with clinic measurements, detection of small but clinically meaningful differences in drug treatment groups9,10 is more likely to occur. Ambulatory monitoring also allows improved evaluation of pharmacodynamic effects of any drug, including the NSAIDs.6,7 For example, in the Celecoxib Rofecoxib Efficacy and Safety in Comorbidities Evaluation Trial (CRESCENT), destabilization of systolic BP control occurred for ≈18 of the 24 hours after dosing of rofecoxib at standard osteoarthritis doses of 25 mg each morning.8 In contrast, no changes from baseline in 24-hour systolic BP were observed with celecoxib or naproxen at …

Over the past few years noninvasive and invasive techniques have allowed a better appreciation of vascular changes in hypertensive humans and experimental animals.1 Large arteries undergo outward hypertrophic remodeling and increased stiffness with aging,2–4 and in hypertension there may be an acceleration of this process leading to enhanced pulse pressure. A reduced aortic diameter in middle-aged hypertensive subjects may also play a role in increases in pulse pressure through increased specific impedance,5 contradicting the classic hypertensive aortic phenotype characterized by vascular wall degeneration and calcification and increased aortic diameter. In advanced hypertension, however, the elastic laminae undergo duplication and fragmentation, with increased deposition of collagen and fetal (EIIIA) fibronectin, contributing to increased stiffness. Classically the remodeling of small arteries in hypertension has been associated with increased media thickness, but recent studies have demonstrated that 2 types of remodeling are found, inward eutrophic or inward hypertrophic remodeling, depending on whether the media cross-sectional area is enlarged (true hypertrophy).6–9 Although eutrophic remodeling is usually found in essential (primary) hypertension in humans and spontaneously hypertensive rats (SHRs); in secondary hypertension such as in renovascular hypertension, primary aldosteronism, or in pheochromocytoma10; in hypertension associated with diabetes mellitus11,12; and in acromegaly,13 hypertrophic remodeling has been described. In mineralocorticoid hypertension in rodents14,15 and in salt-sensitive Dahl rats,16 in both of which the endothelin (ET) system is activated, remodeling of small arteries is also hypertrophic (see below). Thus, when the renin-angiotensin system is even mildly activated (primary hypertension and SHRs), remodeling is usually eutrophic. In salt-dependent hypertension, diabetes mellitus, and malignant hypertension, all conditions in which the ET system is activated, remodeling is hypertrophic.17 Hyperplasia of vascular smooth muscle cells (VSMCs) is found in small arteries of …

Hypertension and Chronic Kidney Disease in the Elderly