Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0020538 (hypertension)
 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The practical pharmacological approaches currently available to palliate the cognitive and functional losses in early Alzheimer's disease (AD) include cholinesterase inhibitors (ChEI), antioxidants (e.g., vitamin E), anti-inflammatory agents, estrogen, seligiline, vasoactive agents, and ginkgo biloba. Reviewing available data on these therapies and using models from medical illnesses such as cancer and hypertension, we highlight the urgent need for evaluating combination therapies in early AD.
 ...
PMID:Combination therapy for early Alzheimer's disease: what are we waiting for? 977 22

The resistance to insulin (insulin resistance, IR) is a common feature and a possible link between such frequent disorders as non-insulin dependent diabetes mellitus (NIDDM), hypertension and obesity. Pharmacological amelioration of IR and understanding its pathophysiology are therefore essential for successful management of these disorders. In this review, we will discuss the mechanisms of action of thiazolidinediones (TDs), a new family of insulin-sensitizing agents. Experimental studies of various models of IR and an increasing number of clinical studies have shown that TDs normalize a wide range of metabolic abnormalities associated with IR. By improving insulin sensitivity in skeletal muscles, the adipose tissue and hepatocytes, TDs reduce fasting hyperglycaemia and insulinaemia. Furthermore, TDs markedly influence lipid metabolism--they decrease plasma triglyceride, free fatty acid and LDL-cholesterol levels, and increase plasma HDL-cholesterol concentrations. Although TDs do not stimulate insulin secretion, they improve the secretory response of beta cells to insulin secretagogues. TDs act at various levels of glucose and lipid metabolism--ameliorate some defects in the signalling cascade distal to the insulin receptor and improve glucose uptake in insulin-resistant tissues via increased expression of glucose transporters GLUT1 and GLUT4. TDs also activate glycolysis in hepatocytes, oppose intracellular actions of cyclic AMP, and increase intracellular magnesium levels. TDs bind to peroxisome proliferator activating receptors gamma (PPAR gamma), members of the steroid/thyroid hormone nuclear receptor superfamily of transcription factors involved in adipocyte differentiation and glucose and lipid homeostasis. Activation of PPAR gamma results in the expression of adipocyte-specific genes and differentiation of various cell types in mature adipocytes capable of active glucose uptake and energy storage in the form of lipids. Furthermore, TDs inhibit the pathophysiological effects exerted by tumour-necrosis factor (TNF alpha), a cytokine involved in the pathogenesis of IR. These effects are most likely also mediated by stimulation of PPAR gamma. In mature adipocytes, PPAR gamma stimulation inhibits stearoyl-CoA desaturase 1 (SCD1) enzyme activity resulting in a change of cell membrane fatty acid composition. Apart from their metabolic actions, TDs modulate cardiovascular function and morphology independently of the insulin-sensitizing effects. TDs decrease blood pressure in various models of hypertension as well as in hypertensive insulin-resistant patients, and inhibit proliferation, hypertrophy and migration of vascular smooth muscle cells (VSMC) induced by growth factors. These processes are considered to be crucial in the development of vascular remodelling, atherosclerosis and diabetic organ complications. TDs induce vasodilation by blockade of Ca2+ mobilisation from intracellular stores and by inhibition of extracellular calcium uptake via L-channels. Furthermore, TDs interfere with pressor systems (catecholamines, renin-angiotensin system) and enhance endothelium-dependent vasodilation. A key role of TDs effects in vascular remodelling is played by inhibition of the mitogen-activated protein (MAP) kinase pathway. This signalling pathway is important for VSMC growth and migration in response to stimulation with tyrosine-kinase dependent growth factors. In addition to the vasoprotective mechanisms mentioned above, troglitazone, the latest representative of this pharmacological group, possesses antioxidant actions comparable to vitamin E. In summary, TDs have the unique ability to attack mechanisms responsible for metabolic alterations as well as for vascular abnormalities characteristic for IR. Therefore, TDs represent a powerful research tool in attempts to find a common denominator underlying the pathophysiology of the metabolic syndrome X. A recently reported link between MAP kinase signalling pathway and PPAR gamma
 ...
PMID:Thiazolidinediones--tools for the research of metabolic syndrome X. 980 67

Approximately 80% of all patients with diabetes die of cardiovascular disease. The traditional management of type 2 diabetes has been ineffective in altering this dismal prognosis. Insulin resistance is the fundamental defect of type 2 diabetes. Insulin resistance often leads to hyperinsulinemia, which is associated with hypertension, atherogenic dyslipidemia, left ventricular hypertrophy, impaired fibrinolysis, visceral obesity, and sedentary lifestyle. Although all these conditions are associated with atherosclerosis and adverse cardiovascular events, the therapeutic efforts in patients with diabetes have focused predominantly on normalizing glucose levels. Improved insulin sensitivity through lifestyle modifications or pharmacologic therapy (troglitazone and metformin) will lower both insulin and glucose levels as well as diminish dyslipidemia and hypertension. In contrast, sulfonylurea agents lower glucose by increasing insulin levels and may increase the risk of cardiovascular events. Therapy including aspirin, lipid agents (for example, statins), angiotensin-converting enzyme inhibitors, beta-adrenergic blockers, postmenopausal estrogen replacement, and vitamin E should be considered for patients with type 2 diabetes. In most patients with diabetes who have multivessel coronary artery disease, coronary artery bypass grafting is superior to coronary angioplasty for improving long-term cardiovascular prognosis. This superiority is mediated in part by the use of a left internal mammary graft to the left anterior descending coronary artery. Urgent coronary angioplasty or thrombolytic therapy should be considered for all patients with diabetes who have acute myocardial infarction.
 ...
PMID:Improving the adverse cardiovascular prognosis of type 2 diabetes. 1006 57

Lowering cholesterol can reduce the incidence of coronary heart disease. Treating hypertension reduces overall mortality and is most effective in reducing the risk of coronary heart disease in older patients. Smoking cessation reduces the level of risk to that of nonsmokers within about three years of cessation. Aspirin is likely to be an effective means of primary prevention, but a group in whom treatment is appropriate has yet to be defined. Evidence that supplementation with vitamin A or C reduces the risk of coronary heart disease is inadequate; the data for use of vitamin E are inconclusive. Epidemiologic evidence is sufficient to recommend that most persons increase their levels of physical activity. Lowering homocysteine levels through increased folate intake is a promising but unproven primary prevention strategy. Hormone replacement therapy was associated with reduced incidence of coronary heart disease in epidemiologic studies but was not effective in a secondary prevention trial.
 ...
PMID:Primary prevention of CHD: nine ways to reduce risk. 1059 14

In this review, therapeutic trials for treatment of IgA nephropathy (Berger's disease) are reviewed and discussed. No disease-specific therapy exists. For treatment of hypertensive patients, angiotensin converting enzyme (ACE) inhibitors are preferred. They also decrease proteinuria and probably slow disease progression. However, there are still no controlled data on the effectiveness of ACE-inhibitors in the absence of hypertension or proteinuria. Renewed enthusiasm for treatment with fish oil arose after the publication of a randomized controlled trial in 1994 and long-term follow-up data of the trial cohort in 1998. Corticoid therapy in IgA nephropathy has been advocated for patients with nephrotic syndrome or crescentic disease. A recent non-randomised trial with long-term follow-up suggests that, in the presence of moderate proteinuria, corticosteroids may ameliorate renal function if administered before the creatinine clearance has decreased below 70 ml/min. Preliminary data suggest that mycophenolate mofetil (MMF) may reduce the risk of clinically significant IgA nephropathy recurring in kidney allografts. Many other promising treatment approaches have been tested, but in most instances results are insufficient for unequivocal conclusions. Several randomized controlled clinical trials are currently testing prednisone, fish oil, ACE-inhibitors, cyclophosphamide, MMF and vitamin E. In the absence of a disease-specific treatment, control of hypertension, proteinuria and probably dyslipidemia are pivotal. Chronic or recurrent infection including ton-sillitis should be treated effectively. Control of daily protein intake to 0.7-0.8 g/kg body weight may retard disease progression.
 ...
PMID:Treatment of immunoglobulin A nephropathy. 1039 61

In the past, many have avoided nuts because of their high fat content. The Dietary Approaches to Stop Hypertension (DASH) diet, however, recommends regular consumption of this food along with seeds and dried beans (4-5 servings per week) as part of a diet to control hypertension. Nuts are nutrient-dense and most of their fat is unsaturated. They are also perhaps the best natural source of vitamin E and are relatively concentrated repositories of dietary fiber, magnesium, potassium, and arginine, the dietary precursor of nitric oxide. Human feeding studies have demonstrated reductions of 8-12% in low-density lipoprotein (LDL) cholesterol when almonds and walnuts are substituted for more traditional fats. Other studies show that macadamias and hazelnuts appear at least as beneficial as fats in commonly recommended diets. Whether consuming modest quantities of nuts daily may promote weight gain is not known with certainty, but preliminary data suggest that this is unlikely. Four of the best and largest cohort studies in nutritional epidemiology have now reported that eating nuts frequently is associated with a decreased risk of coronary heart disease of the order of 30-50%. The findings are very consistent in subgroup analyses and unlikely to be due to confounding. Possible mechanisms include reduction in LDL cholesterol, the antioxidant actions of vitamin E, and the effects on the endothelium and platelet function of higher levels of nitric oxide. Although nuts may account for a relatively small percentage of dietary calories, the potential interacting effects of these factors on disease risk may be considerable.
 ...
PMID:Nut consumption, lipids, and risk of a coronary event. 1041 Mar

Quality and number of subjects in blinded controlled clinical trials about the nutrition and dietary supplements discussed here is variable. Glucosamine sulfate and chondroitin sulfate have sufficient controlled trials to warrant their use in osteoarthritis, having less side effects than currently used nonsteroidal anti-inflammatory drugs, and are the only treatment shown to prevent progression of the disease. Dietary supplements of ephedrine plus caffeine for weight loss (weight loss being the current first line recommendation of physicians for osteoporosis) show some promise, but are not sufficient in number of study subjects. Phenylpropanolamine is proven successful in weight loss. Both ephedrine and phenylpropanolamine have resulted in deaths and hence are worrisome [table: see text] as an over-the-counter dietary supplement. Other commonly used weight loss supplements like Cola acuminata, dwarf elder, Yohimbine, and Garcinia camborgia are either lacking controlled clinical trials, or in the case of the last two supplements, have clinical trials showing lack of effectiveness (although Garcinia has been successful in trials as part of a mixture with other substances, it is unclear if it was a necessary part of the mixture). Safety of these weight loss supplements is unknown. Chromium as a body building supplement for athletes appears to have no efficacy. Creatine may help more in weight lifting than sprinting, but insufficient study subjects and safety information make more studies necessary. Carbohydrate loading is used commonly before endurance competitions, but may be underused as it may be beneficial for other sport performances. Supplements for muscle injury or cramps have had too few studies to determine efficacy. Although proper rehydration with fluids and electrolytes is necessary, a paucity of actual studies to maximize prophylactic treatment for exercise induced cramping still exists. Nutritional supplements for cardiovascular disorders are generally geared to prevention. The United States Department of Agriculture has good recommendations to prevent atherosclerosis; a stricter version by Ornish was shown to reverse coronary heart disease, and the low meat, high fruit, and vegetable DASH diet has been found to decrease hypertension. The epidemiologic studies of hyperhomocysteinemia are impressive enough to give folic acid (or vitamin B6 or B12) supplements to those with elevated homocysteine levels and test patients who have a history of atherosclerotic disease, but no controlled clinical trials have been completed. Soluble fiber has several positive studies in reduction of cholesterol levels and generally is accepted. The data on vitamin E are the most confusing. This vitamin was not helpful in cerebrovascular prevention in China and not helpful at relatively small doses (50 mg) in the United States or Finland against major coronary events. Levels of 400 mg appeared to decrease cardiovascular disease in the United States in studies based on reports by patients and in one large clinical trial. Vitamin E also was successful in prevention of restenosis after PTCA in one clinical trial. Both of these clinical trials need to be repeated in other developed country populations. Some nutritional and dietary supplements are justifiably useful at this point in time. Several meet the criteria of a late Phase 3 FDA clinical trial (where it would be released for public use), but many dietary supplements have insufficient numbers of studies. Some deaths also have occurred with some supplements. If these supplements were required to undergo clinical trials necessary for a new drug by the FDA, they would not be released yet to the public. Several nontoxic supplements appear promising, though need further study. Because they have essentially no toxicity (such as folic acid with B12, soluble fiber, and vitamin E) and may have efficacy, some of these supplementations may be useful now, without randomized clinical trials.
 ...
PMID:Nutrition and dietary supplements. 1051 85

We recently showed elevated reactive oxygen species (ROS), reduced urinary excretion of NO metabolites (NOx), and increased NO sequestration as nitrotyrosine in various tissues in rats with lead-induced hypertension. This study was designed to discern whether the reduction in urinary NOx in lead-induced hypertension is, in part, due to depressed NO synthase (NOS) expression. Male Sprague-Dawley rats were randomly assigned to a lead-treated group (given lead acetate, 100 ppm, in drinking water and regular rat chow), a group given lead and vitamin E-fortified chow, or a normal control group given either regular food and water or vitamin E-fortified food for 12 weeks. Tail blood pressure, urinary NOx excretion, plasma malondialdehyde (MDA), and endothelial and inducible NOS (eNOS and iNOS) isotypes in the aorta and kidney were measured. The lead-treated group exhibited a rise in blood pressure and plasma MDA concentration, a fall in urinary NOx excretion, and a paradoxical rise in vascular and renal tissue eNOS and iNOS expression. Vitamin E supplementation ameliorated hypertension, lowered plasma MDA concentration, and raised urinary NOx excretion while significantly lowering vascular, but not renal, tissue eNOS and iNOS expression. Vitamin E supplementation had no effect on either blood pressure, plasma MDA, or NOS expression in the control group. The study also revealed significant inhibition of NOS enzymatic activity by lead in cell-free preparations. In conclusion, lead-induced hypertension in this model was associated with a compensatory upregulation of renal and vascular eNOS and iNOS expression. This is, in part, due to ROS-mediated NO inactivation, lead-associated inhibition of NOS activity, and perhaps stimulatory actions of increased shear stress associated with hypertension.
Hypertension 1999 Oct
PMID:Nitric oxide synthase expression in the course of lead-induced hypertension. 1052 26

Vitamin E is an antioxidant that has been demonstrated to improve insulin action. Glutathione, another natural antioxidant, may also be important in blood pressure and glucose homeostasis, consistent with the involvement of free radicals in both essential hypertension and diabetes mellitus. Our group has recently suggested that the effects of reduced glutathione on glucose metabolism may be mediated, at least in part, by intracellular magnesium levels (Mg([i])). Recent evidence suggests that vitamin E enhances glutathione levels and may play a protective role in magnesium deficiency-induced cardiac lesions. To directly investigate the effects of vitamin E supplementation on insulin sensitivity in hypertension, in relation to the effects on circulating levels of reduced (GSH) and oxidized (GSSG) glutathione and on Mg([i]), we performed a 4-week, double-blind, randomized study of vitamin E administration (600 mg/d) versus placebo in 24 hypertensive patients and measured whole-body glucose disposal (WBGD) by euglycemic glucose clamp, GSH/GSSG ratios, and Mg([i]) before and after intervention. The relationships among WBGD, GSH/GSSG, and Mg([i]) in both groups were evaluated. In hypertensive subjects, vitamin E administration significantly increased WBGD (25.56+/-0.61 to 31.75+/-0.53 micromol/kg of fat-free mass per minute; P<0.01), GSH/GSSG ratio (1.10+/-0.07 to 1.65+/-0.11; P<0.01), and Mg([i]) (1.71+/-0.042 to 1.99+/-0.049 mmol/L; P<0.01). In basal conditions, WBGD was significantly related to both GSH/GSSG ratios (r=0.58, P=0.047) and Mg([i]) (r=0.78, P=0.003). These data show a clinical link between vitamin E administration, cellular magnesium, GSH/GSSG ratio, and tissue glucose metabolism. Further studies are needed to explore the cellular mechanism(s) of this association.
Hypertension 1999 Oct
PMID:Effects of vitamin E and glutathione on glucose metabolism: role of magnesium. 1052 98

The Women's Health Study (WHS) is a randomized, double-blind, placebo-controlled trial designed to evaluate the balance of benefits and risks of low-dose aspirin and vitamin E in the primary prevention of cardiovascular disease and cancer in women. A total of 39,876 female health professionals, age 45 years or older and without a history of cardiovascular disease or cancer (other than nonmelanoma skin cancer), were randomized in a 2x2 factorial design to one of four treatment groups: active aspirin and vitamin E placebo, aspirin placebo and active vitamin E, both active agents, or both placebos. The process of randomization was successful, as evidenced by the equal distribution of a large number of baseline demographic, lifestyle, and health history characteristics among the four treatment groups. Similar distribution of known potential confounders, as well as the large sample size, provides reassuring evidence that unmeasured or unknown potential confounders are also equally distributed. As expected in a clinical trial, the women in the study are healthier in some respects than the general population, but they have very comparable rates of obesity, hypertension, and elevated cholesterol. With adequate duration of treatment and follow-up, this trial will provide important and relevant information on the balance of benefits and risks of aspirin and vitamin E supplementation in the primary prevention of cardiovascular disease and cancer in women.
 ...
PMID:Baseline characteristics of participants in the Women's Health Study. 1071 1


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>