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Current Hypertension
Reviews
ISSN: 1573-4021
Current Hypertension Reviews
Volume 5, Number 4, November 2009
Contents
Vascular Effects of Insulin and Their Relation to Endothelial
Dysfunction, Insulin Resistance and Hypertension
Pp. 251-261
Manfredi Tesauro, Micaela Iantorno, Francesca Schinzari and
Carmine Cardillo
[Abstract] [Full Text
Article]
The Role of EC-IC Bypass in Critical Cerebral
Hemodynamics of Different Origin Pp. 262-272
Bernhard R. Fischer, Stefan Palkovic, Markus Holling, Matthias
Weckesser, Thomas Niederstadt and Hansdetlef Wassmann
[Abstract] [Full Text
Article]
Silent Partner in Blood Vessel Homeostasis?
Pervasive Role of Nitric Oxide in Vascular Disease
Pp. 273-282
Ruba S. Deeb, Brian D. Lamon and David P. Hajjar
[Abstract] [Full Text
Article]
Vascular Sex Hormone Receptors and their Specific
Modulators in the Management of Postmenopausal Cardiovascular
Disease Pp. 283-306
Graciliano R. A. do Nascimento, Yaskara V. R.
Barros, Amanda K. Wells and Raouf A. Khalil
[Abstract] [Full Text
Article]
Hypertension and Compliance to Treatment in
the Primary Care Setting: Key Issues from the Literature Review
Pp. 307-312
Emmanouil K. Symvoulakis and Christos Lionis
[Abstract] [Full Text
Article]
Blood Pressure and Childhood Obesity
Pp. 313-320
M. Loredana Marcovecchio, Francesco Chiarelli and Angelika
Mohn
[Abstract] [Full Text
Article]
Current Status of Renal Arterial Endovascular
Interventions Pp. 321-332
Christopher S. Morris
[Abstract] [Full Text
Article]
Abstracts
[Back to top]
[Full Text Article]
Vascular Effects of Insulin and Their Relation to
Endothelial Dysfunction, Insulin Resistance and Hypertension
Manfredi Tesauro, Micaela Iantorno, Francesca Schinzari and
Carmine Cardillo
Over the last ten years it has become clear that vascular
actions of insulin extend beyond its ability to increase skeletal
muscle blood flow and glucose uptake. In addition to its role
in regulating glucose, protein, and fatty acid metabolism
insulin exhibits distinct effects on the vascular system.
In this review we will clarify the influence exerted by insulin
in the maintenance of endothelial function and the relation-ship
between insulin resistance, endothelial dysfunction and hypertension.
The mechanisms by which insulin resistance leads to endothelial
dysfunction are multiple and complex. Most of the abnormalities
present in the insulin resistance syn-drome (obesity, hyperglicemia,
hypertension, dyslipidemia) are linked to endothelial dysfunction.
Insulin vasodilates skeletal muscle vasculature through release
of nitric oxide (NO), a mechanism that accounts for 30% of
insulin overall ac-tion to stimulate glucose uptake. On the
one hand, PI3-kinase-dependent insulin signalling pathways
in endothelium re-lated to production of NO share striking
similarities with metabolic pathways in skeletal muscle that
promote glucose up-take. On the other hand, distinct non-metabolic
insulin signaling pathways (MAPK-dependent insulin signalling
path-ways) regulate secretion of the vasoconstrictor endothelin-1
(ET-1) from endothelium. Insulin resistance is characterized
by the specific impairment of PI 3-kinase-dependent signalling
that causes imbalance between NO and ET-1 production, leading
to reduction of blood flow that, in turn, worsens insulin
resistance. Insulin resistance is the common metabolic de-fect
underlying type 2 diabetes, hypertension, obesity, dyslipidemia
and coronary heart diseases; therefore, improving in-sulin
sensitivity may provide an opportunity for simultaneous therapeutic
strategies on metabolic and cardiovascular dis-eases.
[Back to top]
[Full Text
Article]
The Role of EC-IC Bypass in Critical Cerebral
Hemodynamics of Different Origin
Bernhard R. Fischer, Stefan Palkovic, Markus Holling, Matthias
Weckesser, Thomas Niederstadt and Hansdetlef Wassmann
Stroke is a great matter of interest especially in the
industrialised countries, because of pronounced morbidity
and mortality. Recurrent ischemic brain attacks are usually
caused due to embolism by arrhythmic heart diseases or by
occlusive disease of carotid artery (CA) due to atherosclerosis,
furthering with risk factors such as hypertension, metabolic
disorders, smoking, and other life-style factors.
In patients with CA occlusion and reduced cerebrovascular
reserve capacity (CVR), revealed by different technical modalities
of CCT, MRI or PET, the EC-IC bypass can apparently prevent
recurrent ischemic attacks.
Some studies as well as own experiences with brain revascularisation
by means of EC-IC bypass, has documented cessation of symptoms
in majority of patients. Brain revascularisation should be
taken into account in the proper group of patients with occlusion
of CA, if sufficient anticoagulating therapy is not effective.
Which of the patients with recurrent ischemic stroke based
on occluded CA are proper candidates for the revascularization
is not definitive. Further trials especially for redefined
subgroups of patients must bring decision in this matter,
as recommended by the Carotid Occlusion Surgery Study
group. Unfortunately, the data published in 1985 by the
EC-IC Bypass Study Group do not considered diverse
subgroups of patients and their differed CVR owing to occlusion
of internal carotid artery. This issue should be a matter
of interest for the future.
[Back to top]
[Full Text
Article]
Silent Partner in Blood Vessel Homeostasis?
Pervasive Role of Nitric Oxide in Vascular Disease
Ruba S. Deeb, Brian D. Lamon and David P. Hajjar
The endothelium is a rich source of biological mediators
that serve to control blood flow, temper inflammation and
maintain local homeostasis. Endothelium-derived nitric oxide
(NO) is the prototype of these molecules and is critical in
preventing the initiation and progression of vascular disease.
Consistent with a central role for NO in vascular disease,
disruptions in its production and/or bioavailability have
been linked to hypertension, diabetes, hypercholesterolemia,
obesity, aging, and smoking. Furthermore substrate and cofactor
bioavailability, NOS isoform expression profiles and oxidative
stress are crucial determinants as to whether homeostatic
levels of NO are maintained in blood vessels. In addition
to its direct actions, NO is an important modulator of other
vasoregulatory pathways such as cyclooxygenase (COX)-derived
eicosanoid production and angiotensin II generation by the
renin-angiotensin system. Furthermore, NO may direct the selectivity
of COX-2 inhibitors; a finding relevant to controversies associated
with the use of these drugs. Herein, we examine pathways that
are directly or indirectly modified by alterations in NO synthesis
and that are targetable for the development of novel, effective
and safe agents for the treatment of cardiovascular disease.
[Back to top]
[Full Text
Article]
Vascular Sex Hormone Receptors and their Specific
Modulators in the Management of Postmenopausal Cardiovascular
Disease
Graciliano R. A. do Nascimento, Yaskara V. R.
Barros, Amanda K. Wells and Raouf A. Khalil
Cardiovascular disease (CVD) is more common in men and
postmenopausal women than premenopausal women, suggesting
vascular benefits of female sex hormones. Studies on the vasculature
have identified estrogen receptors ERα,
ERβ
and a novel estrogen binding membrane protein GPR30, that
mediate genomic and/or non-genomic effects. Estrogen promotes
endothelium-dependent relaxation by inducing the production/activity
of nitric oxide, prostacyclin, and hyperpolarizing factor,
and inhibits the mechanisms of vascular smooth muscle contraction
including [Ca2+]i,
protein kinase C, Rho kinase and mitogen-activated protein
kinase. Additional effects of estrogen on the cytoskeleton,
matrix metalloproteinases and inflammatory factors contribute
to vascular remodeling. However, the experimental evidence
did not translate into vascular benefits of menopausal hormone
therapy (MHT), and the HERS, HERS-II and WHI clinical trials
demonstrated adverse cardiovascular events. The discrepancy
has been partly related to delayed MHT and potential changes
in the vascular ER amount, integrity, affinity, and downstream
signaling pathways due to the subjects’ age and preexisting
CVD. The adverse vascular effects of MHT also highlighted
the need of specific modulators of vascular sex hormone receptors.
The effectiveness of MHT can be improved by delineating the
differences in pharmacokinetics and pharmacodynamics of natural,
synthetic, and conjugated equine estrogens. Estriol, “hormone
bioidenticals” and phytoes-trogens are potential estradiol
substitutes. The benefits of low dose MHT, and transdermal
or vaginal estrogens over oral preparations are being evaluated.
Specific ER modulators (SERMs) and ER agonists are being developed
to maximize the effects on vascular ERs. Also, the effects
of estrogen are being examined in relation to the levels and
effects of other sex hormones including progesterone and androgens.
Thus, the experimental vascular benefits of estrogen can be
translated to the outcome of MHT in postmenopausal CVD, as
more specific modulators of sex hormone receptors become available
and are used at the right dose, route of administration and
timing, depending on the subject’s age and preexisting
cardio-vascular condition.
[Back to top]
[Full Text
Article]
Hypertension and Compliance to Treatment in
the Primary Care Setting: Key Issues from the Literature Review
Emmanouil K. Symvoulakis and Christos Lionis
The lack of effective hypertension management increases
the risk of cardiovascular events. Issues of compliance to
antihypertensive treatment are commonly seen as the main cause
of not obtaining optimal blood pressure control, despite the
availability of clinically well tolerated antihypertensive
drug therapies.
Our focus will be, therefore, on factors related to patient,
physician and health care delivery process reported to influence
the adherence to antihypertensive treatment and, subsequently,
to affect blood pressure lowering.
Research efforts within primary care settings should be accomplished
to develop and to implement initiatives that improve the overall
management of hypertension and ‘primarily’ prevent
phenomena of insufficient adherence to treatment.
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[Full Text
Article]
Blood Pressure and Childhood Obesity
M. Loredana Marcovecchio, Francesco Chiarelli and Angelika
Mohn
Childhood obesity is associated with a significant increased
risk for several metabolic and cardiovascular complications,
including hypertension. The main mechanisms implicated in
the pathogenesis of high blood pressure in relation to increased
body weight are insulin resistance/hyperinsulinemia, sympathetic
nervous system hyperactivity and alterations in vascular structure
and function. Obesity-related hypertension is associated with
cardiovascular complications already during childhood and
with an increased risk of coronary heart disease in adulthood.
A high prevalence of the non-dipping phenomenon has also been
detected in obese children and adolescents and this is worrying
as this condition is associated with end-organ damage. Assessing
blood pressure is therefore particularly important in obese
children and adolescents for an early detection of its alterations.
Ambulatory blood pressure monitoring represents an important
method of measuring blood pressure, particularly in the suspicion
of white-coat hypertension, masked hypertension and non-dipping
phenomenon.
Prevention and treatment of childhood obesity represent important
means in order to prevent and reduce the incidence of hypertension
and the associated cardiovascular risk. Reduction in body
weight is generally the first step in the management of obesity-related
hypertension. However, in severe cases or in cases non responsive
to lifestyle interventions, drug therapy should be considered.
[Back to top]
[Full Text
Article]
Current Status of Renal Arterial Endovascular
Interventions
Christopher S. Morris
Endovascular renal arterial interventions remain important
treatment strategies for symptomatic renal artery stenoses
causing either renovascular hypertension, renal insufficiency,
or cardiac disturbance syndromes. Since endovascular intervention
has not been shown to be efficacious over optimal medical
therapy, it should be reserved for certain specific indications,
as well as whenever medical therapy has failed. This review
will discuss the current indications, patient selection methods,
technique, imaging follow up, adjunctive revascularization
techniques,and complications of endovascular treatment of
renal artery stenoses, as well as the current trials comparing
endovascular treatment to medical therapy.
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