Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P50583 (asymmetrical)
 12,197 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Epidemiological associations are now well-established between insulin resistance, the metabolic syndrome and worsened cardiovascular outcomes. A direct role of insulin in vascular biology is also now broadly recognized. Specifically, insulin can directly stimulate the action of nitric oxide synthase, an effect that can be demonstrated both in vitro and in vivo. Insulin resistance, whether present endogenously or produced experimentally through exposure to fatty acids, glucosamine or tumour necrosis factor alpha, is associated with impaired endothelium-dependent vasodilation and, specifically, with impaired insulin-stimulated vasodilation. A number of potential molecular explanations for these observations are being pursued, with evidence to support a number of concurrent pathogenic mechanisms. These include insulin resistance-associated reductions in nitric oxide availability due to increases in oxidative stress (not requiring the presence of hyperglycemia), reduced availability of tetrahydrobiopterin and excess levels of asymmetrical dimethylarginine. A strong body of evidence also supports an excess of the vasoconstrictor endothelin, which may result directly from hyperinsulinemia and/or indirectly due to a loss of the suppressive effects of nitric oxide on endothelin production and action. The current leading edge of investigations into the association between insulin-resistant states and vascular dysfunction involves the expanding repertoire of adipocyte-derived hormones. Of these, particular interest has been focused on adiponectin, which has both vascular and metabolic actions, and may contribute importantly to the connection between metabolism and vascular function. Progress along these novel lines of investigation will continue to expand the understanding of the mechanisms linking insulin resistance, the metabolic syndrome and vascular disease.
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PMID:Insulin resistance, metabolic syndrome and vascular diseases: update on mechanistic linkages. 1530 8

Hypertension is a major healthcare problem afflicting nearly 50 million individuals in the United States. Despite its strong causal association with cardiovascular disease complications including myocardial infarction, heart failure, and stroke, the majority of patients with hypertension do not achieve optimal blood pressure control. The prevalence of hypertension is expected to increase with the aging population, growing obesity epidemic, and rising incidence of metabolic syndrome. Endothelial dysfunction and reduced nitric oxide (NO) bioactivity represent prominent pathophysiological abnormalities associated with hypertensive cardiovascular disease. Individuals with hypertension exhibit blunted epicardial and resistance vascular dilation to endothelium-derived nitric oxide (EDNO) agonists in the peripheral and coronary circulation that likely contributes to mechanisms of altered vascular tone in hypertension. The amino acid L-arginine serves as the principal substrate for vascular NO production. Numerous studies, though not uniformly, demonstrate a beneficial effect of acute and chronic L-arginine supplementation on EDNO production and endothelial function, and L-arginine has been shown to reduce systemic blood pressure in some forms of experimental hypertension. This brief review discusses the potential role of L-arginine in hypertension, and reviews possible mechanisms of L-arginine action including modulation of EDNO production, alteration of asymmetrical dimethylarginine (ADMA):L-arginine balance, and possible improvement of insulin sensitivity. In view of the rising prevalence of hypertension, randomized human clinical studies investigating the potential therapeutic role of L-arginine may be warranted.
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PMID:L-arginine and hypertension. 1546 90

The endogenous nitric oxide-synthase inhibitor asymmetrical dimethyl-L-arginine (ADMA) is elevated in patients with increased risk for arteriosclerosis. Obesity is a risk factor for cardiovascular disease. We measured plasma ADMA concentrations in morbidly obese women before and after weight loss following gastroplastic surgery. ADMA and symmetrical dimethyl-L-arginine concentrations were analyzed by HPLC from 34 female patients (age 41 +/- 7 yr) with a body mass index (BMI) of 49 +/- 1 kg/m2 before and 14 months after vertical ring gastroplasty. Age-matched healthy women (BMI < 25 kg/m2; n = 24) were studied as controls. After gastroplastic surgery, BMI decreased to 34 +/- 1 kg/m2 in obese women (P < 0.00001), and ADMA concentrations were reduced from 1.06 +/- 0.06 micromol/liter at baseline to 0.81 +/- 0.04 micromol/liter after weight loss (P < 0.00001). Symmetrical dimethyl-L-arginine plasma levels were not affected. ADMA correlated with high-sensitivity C-reactive protein at baseline (r = 0.42; P < 0.05) and after weight loss (r = 0.56; P < 0.005). No association with blood pressure or plasma lipids could be observed. ADMA concentrations were lower in controls (0.68 +/- 0.04 micromol/liter; P < 0.05) compared with obese patients before or after weight reduction. The decrease of highly elevated ADMA concentrations in morbidly obese patients is paralleled by improvement of parameters associated with the metabolic syndrome after weight loss.
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PMID:Weight loss reduces circulating asymmetrical dimethylarginine concentrations in morbidly obese women. 1557 89

Endpoint studies have been performed with fibrates in coronary heart disease since 1971. The results have been confusing - starting with initial benefits in small studies, but contradicted by either minimal benefits in the Coronary Drug Project or adverse noncardiovascular (non-CV) effects in the World Health Organization Clofibrate Study. Fibrates returned for patients with low HDL-C and low LDL-C after a 25% event reduction were seen in the Veterans Affairs HDL Intervention Trial. The greater prominence ascribed to the lipid triad of the metabolic syndrome and the increasing prevalence of diabetes increased the topicality of fibrates given their main action of converting small dense to light buoyant LDL. The Fenofibrate Intervention in Event Lowering in Diabetes (FIELD) Study has carried on the tradition. Fenofibrate therapy in 9795 patients comprising a mixed low-risk primary and a medium-risk secondary prevention cohort resulted in an 11% reduction in coronary events (p = 0.16), a similar but significant reduction in CV events (p = 0.04; number needed to treat = 70). The benefits were concentrated in primary prevention and on nonfatal myocardial events, but the study was confounded by asymmetrical statin drop-in due to the LDL-C-lowering effect of fenofibrate. Safety was generally good, including in combination with statins, but old concerns about sudden death, pancreatitis and venous thrombosis returned. Unexpected benefits were seen with fenofibrate on microvascular endpoints including microalbuminuria and retinopathy. Fenofibrate is a reasonable second-line therapy for dyslipidaemia in diabetes and safe in combination therapy. Its benefits on microvascular disease and in combination therapy require further confirmation.
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PMID:FIELDS of dreams, fields of tears: a perspective on the fibrate trials. 1662 Mar 58

Metabolic syndrome (MetS) denotes a clustering of risk factors that may affect nitric oxide (NO) bioavailability and predispose to cardiovascular diseases, which are delayed by exercise training. However, no previous study has examined how MetS affects markers of NO formation, and whether exercise training increases NO formation in MetS patients. Here, we tested these two hypotheses. We studied 48 sedentary individuals: 20 healthy controls and 28 MetS patients. Eighteen MetS patients were subjected to a 3-month exercise training (E+group), while the remaining 10 MetS patients remained sedentary (E-group). The plasma concentrations of nitrite, cGMP, and ADMA (asymmetrical dimethylarginine; an endogenous nitric oxide synthase inhibitor), and the whole blood nitrite concentrations were determined at baseline and after exercise training using an ozone-based chemiluminescence assay, and commercial enzyme immunoassays. Thiobarbituric acid reactive species (TBA-RS) were measured in the plasma to assess oxidative stress using a fluorometric method. We found that, compared with healthy subjects, patients with MetS have lower concentrations of markers of NO formation, including whole blood nitrite, plasma nitrite, and plasma cGMP, and increased oxidative stress (all P<0.05). Exercise training increased the concentrations of whole blood nitrite and cGMP, and decreased both oxidative stress and the circulating concentrations of ADMA (both P<0.05). These findings show clinical evidence for lower endogenous NO formation in patients with MetS, and for improvements in NO formation associated with exercise training in MetS patients.
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PMID:Enhanced concentrations of relevant markers of nitric oxide formation after exercise training in patients with metabolic syndrome. 1879 38

Gout affects 2.5% of the total UK population and is four times more common in men than women. The peak prevalence and incidence in the UK is in those aged 80-84 years. Gout is associated with comorbidities such as nephrolithiasis, chronic renal impairment, metabolic syndrome, depression and heart disease. It is also associated with increased mortality. Untreated gout can result in disabling irreversible peripheral joint damage and chronic usage-related pain. However, gout is curable. The pathogenic agents that cause gout i.e.urate crystals can be eliminated through a combination of effective patient education and evidence-based, targeted urate-lowering therapy. Gout is caused by the precipitation of monosodium urate crystals in and around a joint. The crystals preferentially form in peripheral, cooler joints and especially in those with osteoarthritis. It is thought that some of these preformed crystals within articular cartilage spill over into the joint space and trigger an acute attack of inflammation. Uric acid is predominantly renally excreted and the common heritable component of gout results from relative inefficiency of urate excretion. Chronic kidney disease, metabolic syndrome and drugs that reduce renal function (e.g. thiazide diuretics, beta-blockers and ACE inhibitors) will all lead to reduced elimination. Patients with chronic gout can present with monoarthritis but more commonly present with asymmetrical polyarthritis or tophi. Joints affected by osteoarthritis are preferentially targeted, the most common sites of involvement are feet, knees, hands and elbows. Diagnosis can be confirmed in primary care by taking a good history and clinical examination. An acute peripheral monoarthritis which reaches its peak within 24 hours and causes 'the worst pain ever experienced' is characteristic of an acute attack. A patient may have co-existing risk factors for gout such as osteoarthritis, obesity, hypertension, renal impairment, diuretic and antihypertensive drug use or increased beer or spirit consumption. A raised serum uric acid can confirm the diagnosis, however, this can be normal in the acute phase. Radiographs are rarely helpful but joint ultrasound may demonstrate deposits in cartilage, the synovium and peri-articular sites.
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PMID:Patients with gout can be cured in primary care. 2560 88