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Query: UMLS:C0020538 (hypertension)
 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A literature review is presented to show that oral contraceptives (OCs) can cause arterial hypertension in women. The occurrence of this side effect varies over the broad range of 1-15%. Thus, in a Polish study of 100 women, the occurrence of hypertension after 1, 3, and 4 years of OC use was 1%, 8%, and 16%, respectively. Most studies on hypertension caused by OCs were performed with pills containing 50-100 mc of estrogens and 1-4 mg of gestagen. Through these studies, a strong correlation was established between the occurrence of hypertension and the dose of estrogens. Normal blood pressure was observed over 3 years in women using pills containing 20-30 ug of estrogens and 150-250 mc of gestagen. Most OCs are combinations of synthetic estrogens with progesterone. Estrogens appear to dominate in the pathogenesis of hypertension caused by OCs. The mechanism of action of estrogens on arterial blood pressure is not clear. Several hypotheses have been proposed, and some of them are briefly discussed. Numerous studies prove that the occurrence of hypertension increases with the age of the woman using OCs. From this review, the conclusion is drawn that physicians should not recommend hormonal agents to women with hypertensive cardiovascular disorders or susceptibility to contraceptive-induced hypertension. Changing from high-to low-dose steroid preparations could become an important step in the future development of OCs.
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PMID:[Hormonal contraceptives and arterial hypertension]. 639 87

A case of acute intestinal vascular necrosis in a 19-year-old user of oral contraceptives (OCs) is described, and hypotheses explaining the digestive complications of synthetic estrogens are reviewed. The patient had originally presented with a violent gastric pain that subsequently spread to the entire abdomen. An abrupt worsening of her condition involved cardiovascular collapse associated with a peritoneal syndrome, vomiting and dehydration, and hyperleukocytosis. Emergency opening of the peritoneum was followed by evacuation of a large quantity of fetid gas and alimentary debris, and observation of a completely necrosed stomach. A careful lavage of the entire intestinal cavity led to temporary improvement, but it became clear during an attempt at gastrectomy that further treatment would be unavailing and the patient died shortly thereafter. Estrogens were believed to be responsible for the digestive necrosis because it occurred in a young woman who had used an estrogen-rich OC for 3 years and who smoked; a hapatic biopsy confirmed the diagnosis. No traces of other risk factors such as hypertension, hyperlipidemia, diabetes, neoplasia, or obesity were observed. Recent publications indicate that OCs are responsible for a certain number of digestive problems, which may include acceleration of intestinal transit, severe diarrhea, rectorrhagia, ischemic or ulcerative colitis, intestinal infarct which is usually localized, and hepatocellular problems ranging from moderate hepatic insufficiency to malignant tumor and Budd-Chiari syndrome. OCs do not modify hemodynamic regimes, but they may cause elevation of fibrinogen and thrombin, diminution of antithrombin III acitivty, increased platelet adhesivity, and decreased fibrinolysis leading to hypercoagulability. These modifications in hemostasis occur in all OC users and are not statistically correlated with occurence of thrombotic accidents. OCs are probably responsible for parietal vascular lesions; experimental injection of synthetic estrogens is associated with both arterial and venous lesions. The most characteristic anomaly is at the level of the intima, with proliferation of smooth muscle cells and increased conjunctive tissue fibers associated with proliferation of the media or the endothelium. The absence of lipid deposits, the simultaneous appearance of arterial and venous lesions, and other evidence argues against and atheromatous origin of parietal lesions. A significant correlation has been found between high levels of anti-synthetic ethinyl estradiol antibodies and the presence of vascular lesions. It is hypothesized that these circulating immune complexes penetrate the vascular walls of OC users and produce lesions, which may depend on factors such as smoking.
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PMID:[Digestive complications of oral contraceptives: a case of extensive digestive necrosis in a young woman]. 647 54

The incidence of thromboses among young women has increased with widespread use of oral contraceptives (OCs) due to the significant thromboembolic risk of estrogen. Estrogens intervene at the vascular, platelet, and plasma levels as a function of hormonal variations in the menstrual cycle, increasing the aggregability of the platelets and thrombocytes, accelerating the formation of clots, and decreasing the amount of antithrombin III. Estrogens are used in medicine to treat breast and prostate cancers and in gynecology to treat dysmenorrhea, during the menopause, and in contraception. Smoking, cardiovascular disease and hypertension, hypercholesterolemia, and diabetes are contraindicators to estrogen use. Thrombosis refers to blockage of a blood vessel by a clot or thrombus. Before estrogens are prescribed, a history of phlebitis, obesity, hyperlipidemia, or significant varicosities should be ruled out. A history of venous thrombosis, hyperlipoproteinemia, breast nodules, serious liver condition, allergies to progesterone, and some ocular diseases of vascular origin definitively rule out treatment with estrogens. A family history of infarct, embolism, diabetes, cancer, or vascular accidents at a young age signals a need for greater patient surveillance. All patients receiving estrogens should be carefully observed for signs of hypertension, hypercholesterolemia, hypercoagulability, or diabetes. Nurses have a role to play in carefully eliciting the patient's history of smoking, personal and family medical problems, and previous and current laboratory results, as well as in informing the patients of the risks and possible side effects of OCs, especially for those who smoke. Nurses should educate patients receiving estrogens, especially those with histories of circulatory problems, to avoid standing in 1 position for prolonged periods, avoid heat which is a vasodilator, avoid obesity, excercise regularly, wear appropriate footgear, and follow other good health practices.
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PMID:[Estrogens and vascular thrombosis]. 692 85

Estrogens are very successful in premenopausal and postmenopausal therapy. Synthetic estrogens, such as ethinyl estradiol and mestranol, are used in hormonal contraception, while natural estrogen are used for treatment during and after climaterium. It seems that the major difference between the action of synthetic and of natural estrogens is at the level of the venous endotelial system. It has been proven that the use of synthetic estrogen used in hormonal contraception can increase the risk of thrombotic accidents, and that the risk is even greater in women over 40, or in smokers. Synthetic estrogens can alter lipid metabolism and blood coagulation, and often lead to hypertension. Such complications are not reported with the use of natural estrogens traditionally used in menopausal and postmenopausal therapy.
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PMID:[Estrogen therapy for the climateric and thromboembolic risk]. 739 92

Vasoprotective drugs decrease the vulnerability of blood vessels to cardiovascular risk factors such as hypertension and hypercholesterolemia. Mechanistic treatment end-points of hypertension (normalization of endovascular pressure) may not correct nonhypertensive components of the pathobiology of hypertension. Estrogen replacement therapy, antihypertensive treatment with angiotensin-converting enzyme inhibitors, and manipulations of nitric oxide metabolism may have beneficial effects on vessels in the absence of blood pressure normalization. Estrogens and L-arginine, the precursor of nitric oxide, can partly correct impaired endothelium-dependent vasodilation, a pathophysiologic hallmark of hypertensive states. Angiotensin-converting enzyme inhibitors preserve endothelium-dependent vasodilation and protect arteries against the atherogenic effects of hypercholesterolemia by a non-hypolipidemic, non-hypotensive mechanism.
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PMID:Vasoprotection and antihypertensive therapy. 760 51

Cardiovascular disease is the most important cause of death even among women. After menopause there is a steep increase in risk factors like LDL-cholesterol and lipoprotein (a) as well as the incidence of hypertension and diabetes mellitus. This is followed by a rise especially in coronary artery disease. Therefore women too have to be included in prevention programs for cardiovascular disease by normalizing risk factors. One means is hormone replacement therapy. Estrogens lower LDL-cholesterol by up to 20% and increase HDL-cholesterol up to 30%. This effect remains even after addition of a suitable progestin. Numerous large scale studies indicate that every other cardiovascular death can be prohibited by the simple measure of hormone replacement therapy. Because of the high rate of cardiovascular disease low incidences of adverse events cannot prevent the marked decrease in total mortality.
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PMID:[Prevention of cardiovascular diseases by hormone replacement in postmenopause]. 865 Oct 5

Estrogens are reported to provide protection against the development of cardiovascular disease in women, but the mechanisms underlying these effects are not well defined. We hypothesized that estrogen might reduce neural cardiovascular tone. We therefore studied responses to exogenous norepinephrine and norepinephrine spillover in 12 perimenopausal women randomized to 8 weeks of estrogen supplementation (estradiol valerate, 2 mg daily, n=7) or placebo (n=5). Forearm blood flow was measured by venous occlusion plethysmography, and vasoactive agents were infused through a brachial artery cannula in doses that did not influence blood pressure or heart rate. Total body and forearm norepinephrine spillover were measured by radiotracer methodology. Forearm vasoconstrictor responses to norepinephrine (25, 50, and 100 ng/min) were attenuated after estrogen supplementation (P=.002). Vasoconstrictor responses to angiotensin II (8, 16, and 32 ng/min) were unchanged postestrogen. There was a significant reduction in total body spillover of norepinephrine after estrogen supplementation (pre-estrogen, 700+/-152; postestrogen, 439+/-150 ng/min; P<.05), but there was no change after placebo. Total body clearance and forearm spillover of norepinephrine were unchanged by either estrogen or placebo. Estrogen supplementation also significantly decreased both systolic and diastolic blood pressures. Therefore, estrogen supplementation in perimenopausal women selectively attenuates vasoconstrictor responses to norepinephrine and reduces total body norepinephrine spillover, which is an index of sympathetic neural activity.
Hypertension 1997 Dec
PMID:Estrogen supplementation decreases norepinephrine-induced vasoconstriction and total body norepinephrine spillover in perimenopausal women. 940 79

Estrogens have been found to reduce the incidence of cardiovascular disease that has been ascribed in part to an increased expression and/or activity of the vasoprotective endothelial NO synthase (NOS III). Some reports have shown that the level of expression of this constitutive enzyme can be upregulated by estrogens. The current study investigates the molecular mechanism of the NOS III upregulation in human endothelial EA.hy 926 cells. Incubation of EA.hy 926 cells with 17beta-estradiol or the more stable 17alpha-ethinyl estradiol enhanced NOS III mRNA and protein expression up to 1.8-fold, without changing the stability of the NOS III mRNA. There was no enhancement of NOS III mRNA after incubation of EA.hy 926 cells with testosterone, progesterone, or dihydrocortisol or when 17alpha-ethinyl estradiol was added together with the estrogen antagonist RU58668, indicating a specific estrogenic response. Nuclear run-on assays indicated that the increase in NOS III mRNA is the result of an estrogen-induced enhancement of NOS III gene transcription. In transient transfection experiments using a 1.6 kb human NOS III promoter fragment (which contains no bona fide estrogen-responsive element, ERE), basal promoter activity was enhanced 1.7-fold by 17alpha-ethinyl estradiol. In electrophoretic mobility shift assays, nuclear extracts from estrogen-incubated EA.hy 926 cells showed no enhanced binding activity either for the ERE-like motif in the human NOS III promoter or for transcription factor GATA. However, binding of transcription factor Sp1 (which is essential for the activity of the human NOS III promoter) was significantly enhanced by estrogens. These data suggest that the estrogen stimulation of the NOS III promoter could be mediated in part by an increased activity of transcription factor Sp1.
Hypertension 1998 Feb
PMID:Estrogens increase transcription of the human endothelial NO synthase gene: analysis of the transcription factors involved. 946 Dec 25

-Estrogens are known to induce cardioprotective effects by inhibiting smooth muscle cell (SMC) growth and neointima formation. However, the use of estrogens as cardioprotective agents is limited by carcinogenic effects in women and feminizing effects in men. If noncarcinogenic and nonfeminizing estrogenlike compounds, such as natural phytoestrogens, afford cardioprotection, this would provide a safe method for prevention of cardiovascular disease in both men and women. Therefore, we evaluated and compared in human aortic SMCs the effects of phytoestrogens (formononetin, genistein, biochanin A, daidzein, and equol) on 2.5% fetal calf serum-induced proliferation (3H-thymidine incorporation and cell number), collagen synthesis (3H-proline incorporation), and total protein synthesis (3H-leucine incorporation) and on PDGF-BB (25 ng/mL)-induced migration (modified Boydens chambers). Moreover, the effects of phytoestrogens on PDGF-BB (25 ng/mL)-induced mitogen-activated protein kinase (MAP kinase) activity in SMCs was also studied. Phytoestrogens inhibited proliferation, collagen and total protein synthesis, migration, and MAP kinase activity in a concentration-dependent manner and in the following order of potency: biochanin A>genistein>equol>daidzein>formononetin. In conclusion, our studies provide the first evidence that in human aortic SMCs phytoestrogens inhibit mitogen-induced proliferation, migration and extracellular matrix synthesis and inhibit/downregulate MAP kinase activity. Thus, phytoestrogens may confer protective effects on the cardiovascular system by inhibiting vascular remodeling and neointima formation and may be clinically useful as a safer substitute for feminizing estrogens in preventing cardiovascular disease in both women and men.
Hypertension 1999 Jan
PMID:Phytoestrogens inhibit growth and MAP kinase activity in human aortic smooth muscle cells. 993 Nov 1

Stroke prevention is a crucial issue because (i) stroke is a frequent and severe disorder, and (ii) acute stroke therapies that are effective at the individual level have only a little impact in term of public health. Stroke prevention consists of the combination of 3 strategies: an optimal management of vascular risk factors, associated when appropriate with antithrombotic therapies, carotid surgery, or both. Primary prevention trials have shown that reducing blood pressure in hypertensive subjects reduces their vascular risk, including stroke. The association of perindopril plus indapamide reduces the vascular risk in patients who have had a stroke or TIA during the last 5 years, irrespective of their baseline blood pressure. Lowering serum cholesterol with statins or gemfibrozil in patients with hypercholesterolemia or coronary heart disease (CHD), reduces the risk of stroke. However, no trial of cholesterol-lowering therapy has been completed in stroke patients. A strict control of high cholesterol levels should be encouraged, because of benefits in terms of CHD. Statins should be prescribed for stroke patients with CHD, or increased cholesterol levels. Cigarette smoking is associated with an increased risk of stroke and should be avoided. Careful control of all risk factors, especially arterial hypertension in type 1 and type 2 diabetics is recommended, together with a strict glycemic control to reduce systemic microvascular complications. Estrogens prescribed in hormone replacement or oral contraceptive therapies are not recommended after an ischemic stroke. It is also recommended to reduce alcohol consumption and obesity, and to increase physical activity in patients at risk for first-ever or recurrent stroke. An optimal management of risk factors for stroke is crucial to reduce the risks of first-ever stroke, recurrent stroke, any vascular event after stroke and vascular death. One of the major public health issues for the coming years will be to focus more on risk factor recognition and management.
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PMID:Stroke prevention: management of modifiable vascular risk factors. 1450 80


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