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Query: UMLS:C0011849 (
diabetes
)
277,896
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Angiotensin II
(ANG II) has multiple effects on cardiovascular and renal cells, including vasoconstriction, cell growth, induction of proinflammatory cytokines, and profibrogenic actions. Recent studies provide evidence that ANG II could stimulate intracellular formation of reactive oxygen species (ROS) such as the superoxide anion (O2-). This ANG II-mediated ROS formation exhibits different kinetic and lower absolute concentrations than those traditionally observed during the respiratory burst of phagocytic cells, but it likely involves similar membrane-bound NAD(P)H-oxidases. Current evidence suggests that ANG II, through AT1-receptor activation, upregulates several subunits of this multienzyme complex, resulting in an increase in intracellular O2- concentration. ROS are involved in several signal pathways, and redox-sensitive transcriptional factors (AP-1, NF-kappaB) have been characterized. ANG II-induced ROS play a pivotal role in several pathophysiologic situations of vascular and renal cells such as hypertension, endothelial dysfunction, nitrate tolerance, atherosclerosis, and cellular remodeling. Although these perceptions suggest that drugs interfering with ANG II effects (ACE inhibitors, AT1 -receptor antagonist) may serve as antioxidants, preventing vascular and renal changes, the clinical studies are not so straightforward. In fact, only specific risk groups, such as patients with
diabetes mellitus
or renal insufficiency, may benefit from ACE inhibitors, whereas hard endpoints showed no advantage for ACE inhibitors in patients with essential hypertension.
...
PMID:Free radical production and angiotensin. 1098 Nov 45
Diabetes mellitus
, a highly prevalent metabolic and vascular disease, affects 155 million people worldwide. Tight blood glucose control can significantly reduce the incidence of diabetic retinopathy, nephropathy, and neuropathy, but does not appear to significantly reduce its macrovascular complications. Several randomized clinical trials indicate that tight blood pressure control can reduce the risk of microvascular and macrovascular complications in patients with
diabetes
and hypertension. Blockade of the renin-angiotensin system (RAS) with angiotensin-converting enzyme (ACE) inhibitors has proven effective both in lowering blood pressure and in independently slowing the progression of nephropathy. If instituted early, ACE inhibitor therapy potentially may prevent progression to end-stage renal disease in normotensive patients with type 1 or 2
diabetes
. Additionally, ACE inhibitors may reduce cardiovascular morbidity and mortality in this patient population.
Angiotensin II
(Ang II) receptor blockers (ARBs), which attenuate the deleterious effects of the RAS via blockade of the Ang II subtype 1 receptor, may also be beneficial. Clinical trials are under way to evaluate this possibility.
...
PMID:Treating high-risk diabetic hypertensive patients with comorbid conditions. 1098 54
The renin-angiotensin system is upregulated with
diabetes
, and this may contribute to the development of a dilated myopathy.
Angiotensin II
(Ang II) locally may lead to oxidative damage, activating cardiac cell death. Moreover,
diabetes
and hypertension could synergistically impair myocardial structure and function. Therefore, apoptosis and necrosis were measured in ventricular myocardial biopsies obtained from diabetic and diabetic-hypertensive patients. Accumulation of a marker of oxidative stress, nitrotyrosine, and Ang II labeling were evaluated quantitatively. The diabetic heart showed cardiac hypertrophy, cavitary dilation, and depressed ventricular performance. These alterations were more severe with
diabetes
and hypertension.
Diabetes
was characterized by an 85-fold, 61-fold, and 26-fold increase in apoptosis of myocytes, endothelial cells, and fibroblasts, respectively. Apoptosis in cardiac cells did not increase additionally with
diabetes
and hypertension.
Diabetes
increased necrosis by 4-fold in myocytes, 9-fold in endothelial cells, and 6-fold in fibroblasts. However,
diabetes
and hypertension increased necrosis by 7-fold in myocytes and 18-fold in endothelial cells. Similarly, Ang II labeling in myocytes and endothelial cells increased more with
diabetes
and hypertension than with
diabetes
alone. Nitrotyrosine localization in cardiac cells followed a comparable pattern. In spite of the difference in the number of nitrotyrosine-positive cells with
diabetes
and with
diabetes
and hypertension, apoptosis and necrosis of myocytes, endothelial cells, and fibroblasts were detected only in cells containing this modified amino acid. In conclusion, local increases in Ang II with
diabetes
and with
diabetes
and hypertension may enhance oxidative damage, activating cardiac cell apoptosis and necrosis.
...
PMID:Myocardial cell death in human diabetes. 1111 Jul 69
Uncontrolled hypertension leads to an increased risk of cardiovascular disease and stroke. Hypertensive patients with concomitant type 2 diabetes are at even greater risk of cardiovascular complications; also, this high-risk patient population is at increased risk of renal disease and, ultimately, renal failure. Prospective morbidity and mortality trials have demonstrated that tight blood pressure control improves the cardiovascular prognosis and provides target organ protection. Current treatment guidelines recommend a target blood pressure of < 130/85 mm Hg for patients with hypertension and
diabetes
.
Angiotensin II
(
A-II
), a major component of the renin-angiotensin system, plays an essential role in the pathophysiology of hypertension and
diabetes
-related renal disease. Currently, the treatment of choice for hypertensive patients with
diabetes
is angiotensin-converting enzyme (ACE) inhibition, but most of the data are limited to patients with type 1 diabetes. Although ACE inhibition is clearly a mechanism for blocking
A-II
formation, inhibition at this site may not be complete, as alternate pathways exist for
A-II
formation. Thus, for interrupting the renin-angiotensin system,
A-II
receptor antagonists theoretically provide advantages over ACE inhibitors in that they directly inhibit
A-II
by binding to the AT(1) receptor subtype. The objectives of this review are to: 1) provide an overview of the associated risk of cardiovascular complications with concomitant hypertension and
diabetes
; 2) demonstrate the cardiovascular benefits of effective blood pressure control in this patient population; 3) review the current treatment guidelines for managing high-risk hypertensive patients; and 4) discuss major, ongoing clinical studies with
A-II
receptor antagonists in patients with concomitant hypertension, type 2 diabetes, and renal disease. (c)2001 Le Jacq Communications, Inc.
...
PMID:Management of high-risk hypertensive patients with diabetes: potential role of angiotensin II receptor antagonists. 1149 50
To determine whether enzymatic p53 glycosylation leads to angiotensin II formation followed by p53 phosphorylation, prolonged activation of the renin-angiotensin system, and apoptosis, ventricular myocytes were exposed to levels of glucose mimicking diabetic hyperglycemia. At a high glucose concentration, O-glycosylation of p53 occurred between 10 and 20 min, reached its peak at 1 h, and then decreased with time.
Angiotensin II
synthesis increased at 45 min and 1 h, resulting in p38 mitogen-activated protein (MAP) kinase-driven p53 phosphorylation at Ser 390. p53 phosphorylation was absent at the early time points, becoming evident at 1 h, and increasing progressively from 3 h to 4 days. Phosphorylated p53 at Ser 18 and activated c-Jun NH(2)-terminal kinases were identified with hyperglycemia, whereas extracellular signal-regulated kinase was not phosphorylated. Upregulation of p53 was associated with an accumulation of angiotensinogen and AT(1) and enhanced production of angiotensin II. Bax quantity also increased. These multiple adaptations paralleled the concentrations of glucose in the medium and the duration of the culture. Myocyte death by apoptosis directly correlated with glucose and angiotensin II levels. Inhibition of O-glycosylation prevented the initial synthesis of angiotensin II, p53, and p38-MAP kinase (MAPK) phosphorylation and apoptosis. AT(1) blockade had no influence on O-glycosylation of p53, but it interfered with p53 phosphorylation; losartan also prevented phosphorylation of p38-MAPK by angiotensin II. Inhibition of p38-MAPK mimicked at a more distal level the consequences of losartan. In conclusion, these in vitro results support the notion that hyperglycemia with
diabetes
promotes myocyte apoptosis mediated by activation of p53 and effector responses involving the local renin-angiotensin system.
Diabetes
2001 Oct
PMID:Hyperglycemia activates p53 and p53-regulated genes leading to myocyte cell death. 1157 21
Angiotensin II
(Ang II) is a vasopressor peptide involved in the pathogenesis of cardiovascular diseases associated with
diabetes mellitus
. We have previously reported that the 5-lipoxygenase-derived products, particularly the cysteinyl leukotrienes (CysLTs), are involved in Ang II-induced contraction. In this study, we demonstrated that CysLTs contribute to the contraction elicited by Ang II in isolated aortas from streptozotocin-induced diabetic (SS) rats but not from insulin-treated diabetic rats, fructose-fed rats, or control rats. In an organ bath, pretreatment with the 5-lipoxygenase inhibitor (AA861, 10 micromol/L) reduced by 37.6+/-8.2% and 30.1+/-10.9% the Ang II-induced contractions in intact and endothelium-denuded aortic rings, respectively, from SS rats. In contrast, the CysLT(1) receptor antagonist (MK571, 1 micromol/L) or the dual CysLT(1)/CysLT(2) receptor antagonist (BAY-u9773, 0.1 micromol/L) did not affect Ang II-induced contraction. In addition, Ang II induced a 6.2+/-1.5-fold increase in CysLT release through the stimulation of the Ang II type 1 receptor. Furthermore, the urinary excretion of leukotriene E(4) was increased in SS rats (leukotriene E(4), 13.7+/-2.9 ng/24 h [SS rats, n=10] versus 1.5+/-0.5 ng/24 h [control rats, n=6]; P<0.0004). These data suggest the activation of the 5-lipoxygenase pathway in SS rats and the involvement of 5-lipoxygenase-derived products, particularly the CysLTs, in Ang II-induced contraction in aortas from SS rats through stimulation of CysLT receptors different from the well-characterized CysLT(1) or CysLT(2) receptor.
...
PMID:Cysteinyl leukotrienes modulate angiotensin II constrictor effects on aortas from streptozotocin-induced diabetic rats. 1170 61
The co-existence of hypertension and
diabetes
dramatically and synergistically increases the risk of microvascular and macrovascular complications. Overwhelming evidence supports aggressive treatment of hypertension in diabetic patients. However, only a small percentage of diabetic hypertensive patients reach their treatment goal of blood pressure (BP) < 130/80 mmHg. Tight BP control is not only cost-effective but also more rewarding than glycaemic control. The optimal goal of BP control in diabetics should be 130/80 mmHg. In subjects with
diabetes
and renal insufficiency, the BP should be lowered to 125/75 mmHg to delay the progression of renal failure. The choice of an antihypertensive agent should be based on proven effects on morbidity and mortality rather than on surrogate parameters such as lipid or glucose. Limited data suggests that an angiotensin converting enzyme inhibitor (ACEI) is the agent of choice, especially in those with proteinuria or renal insufficiency. beta-blockers (betaBs) can be the first-line agent in diabetics with coronary heart disease, while thiazide diuretics (TD) and calcium-channel blockers (CCBs) are the second-line drugs.
Angiotensin II
-receptor blockers (ARBs) may be proven to be as effective as ACEIs in diabetics with hypertension. alpha-adrenergic antagonists (AAAs) should be avoided. Most hypertensive patients require more than one agent to control their BP. There is no evidence to support one combination regimen over others; nevertheless, a combination of an ACEI with a TD or a betaB may be the most cost-effective regimens compared to other combinations.
...
PMID:Pharmacotherapy of hypertension in patients with diabetes mellitus. 1182 18
Recent trials have helped to clarify indications for the initial pharmacological therapy of hypertension. Both the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC VI) and World Health Organization-international Society of Hypertension (WHO-ISH) recommendations should be revised. The more recent trials indicate that: (1) diuretics and beta-blockers appear to be as effective in reducing overall morbidity/ mortality as other agents (Swedish Trial in Old Patients with Hypertension [STOP-2], United Kingdom Prospective
Diabetes
Study [UKPDS], Intervention as a Goal in Hypertension Treatment [INSIGHT], Nordic diltiazem [NORDIL]); (2) the use of an a-blocker results in more cardiovascular events, especially congestive heart failure, when compared with a diuretic (Antihypertensive Therapy and Lipid Lowering Heart Attack Trial [ALLHAT]); (3)the use of an angiotensin-converting enzyme (ACE) inhibitor results in fewer myocardial infarctions and episodes of heart failure than calcium channel blockers in the elderly and in diabetic patients (Fosinopril vs. Amlodipine Cardiovascular Events Randomized Trial [FACET], Appropriate Blood Pressure Control in
Diabetes
[ABCD], STOP-2) - other data (Captopril Prevention Project [CAPPP]) suggest that the use of an ACE inhibitor is preferred in diabetic patients; (4) overall cardiovascular events are similar with calcium channel blockers compared with a diuretic - however, there are fewer strokes with non-dihydropyridine calcium channel blockers (NORDIL) and a trend towards an increase in heart failure and myocardial infarctions with either a dihydropyridine or non-dihydropyridine calcium channel blockers compared with a diuretic (INSIGHT, NORDIL); (5) angiotensin receptor blockers (ARBs) will decrease proteinuria and slow progression of renal disease in type 2 diabetic patients when compared with regimens that do not include an ARB or an ACE inhibitor (Reduction of Endpoints in NIDDM with the
Angiotensin II
Antagonist Losartan [RENAAL], Irbesartan Type II Diabetic Nephropathy Trial [IDNT], Irbesartan Type II Diabetes with Microalbuminuria [IRMA Il]). The debate over initial therapy may be moot. High-risk hypertensive patients should probably be treated initially with combination therapy, one of which should be a diuretic. The use of diuretics and beta-blockers as well as ACE-inhibitors alone or with a diuretic should be considered as initial therapy (a change from JNCVI). Alpha-blockers should be reserved for special situations, i.e. prostatic hypertrophy (in contrast to WHO-ISH recommendations). An ACE-inhibitor or ARB, usually along with a diuretic, can be considered as preferred therapy in hypertensive diabetic patients. Some data suggest equal or greater reduction in strokes with a calcium channel blocker than other medications.
...
PMID:Current recommendations for the treatment of hypertension: are they still valid? 1199 97
Diabetes mellitus
has reached epidemic proportions in many countries and is the most common cause of end stage renal disease (ESRD). The angiotensin II receptor-1 (AT(1)) antagonists losartan and irbesartan have recently been evaluated as renoprotective agents in large clinical trials of patients with Type 2
diabetes
and nephropathy. In the Reduction of End points in Non-insulin-dependent diabetes mellitus with the
Angiotensin II
Antagonist (RENAAL) study, losartan decreased the number of patients reaching the primary end point of a composite of measures of neuropathy. The relative risk reduction was approximately 15% with losartan and this was due to a reduction in both the doubling of creatinine concentration (25%) and of ESRD (28%) but not in death. In the Irbesartan Diabetic Nephropathy Trial (IDNT), the beneficial effect of irbesartan was mainly against the doubling of the baseline creatinine concentration (37% risk reduction) but there was also a 20% reduction in the onset of ESRD. Irbesartan had no effect on mortality. Beneficial effects occurred in addition to blood pressure being controlled by agents other than the AT(1) antagonists. These clinical trials suggest that there may be a class renoprotective action with AT(1) antagonists, although the mechanism is not clear. Patients with Type 2
diabetes
and nephropathy should receive either an AT(1) antagonist or the angiotensin converting enzyme inhibitor ramipril to ensure renoprotection.
...
PMID:Class benefits of AT(1) antagonists in Type 2 diabetes with nephropathy. 1199 40
Despite intense investigation and clinical attention, many challenges remain in the management of the hypertensive patient. It is clear that hypertension remains inadequately controlled worldwide, with the control rate in the United States approximating 27%. Furthermore, several recent studies have underscored that it is frequently difficult to attain control at goal blood pressure (BP) with monotherapy and that adequate control of hypertension based on the newer more intensified BP goals necessitates multiple drug therapy. Indeed, in the recently published landmark trials of angiotensin I receptor antagonists, including the Irbesartan Diabetic Nephropathy Trial (IDNT) and Reduction of Endpoints in Non-insulin-dependent
Diabetes Mellitus
with the
Angiotensin II
Antagonist Losartan (RENAAL), multiple antihypertensive drugs were required to attain goal. A pivotal class of drug required to comprise this regimen is the calcium antagonists. For example, in RENAAL, 78% of patients randomized to losartan required add-on therapy with a calcium antagonist. Calcium antagonists are an important and often necessary component of this multiple drug regimen.
...
PMID:Recent landmark clinical trials: how do they modify the therapeutic paradigm? 1212 Oct 10
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