Asymmetric dimethylarginine (ADMA) and endothelial dysfunction: implications for atherogenesis: [review]

Atherosclerotic coronary heart disease is the leading cause of morbidity and mortality in industrialized countries, and endothelial dysfunction is considered a precursor phenomenon. The nitric oxide produced by the endothelium under the action of endothelial nitric oxide synthase has important antiatherogenic functions. Its reduced bioavailabilty is the beginning of the atherosclerotic process. The addition of two methyl radicals to arginine, through the action of methyltransferase nuclear proteins, produces asymmetric dimethylarginine, which competes with L-arginine and promotes a reduction in nitric oxide formation in the vascular wall. The asymmetric dimethylarginine, which is itself considered a mediator of the vascular effects of the several risk factors for atherosclerosis, can be eliminated by renal excretion or by the enzymatic action of the dimethylarginine dimethylaminohydrolases. Several basic science and clinical research studies suggest that the increase in asymmetric dimethylarginine occurs in the context of chronic renal insufficiency, dyslipidemia, high blood pressure, diabetes mellitus, and hyperhomocysteinemy, as well as with other conditions. Therapeutic measures to combat atherosclerosis may reverse these asymmetric dimethylarginine effects or at least reduce the concentration of this chemical in the blood. Such an effect can be achieved with competitor molecules or by increasing the expression or activity of its degradation enzyme. Studies are in development to establish the true role of asymmetric dimethylarginine as a marker and mediator of atherosclerosis, with possible therapeutic applications. The main aspects of the formation and degradation of asymmetric dimethylarginine and its implication in the atherogenic process will be addressed in this article.

Metabolic syndrome patient compliance with drug treatment

OBJECTIVES: 1) To evaluate the compliance with drug treatment in patients with metabolic syndrome. 2) To determine association between access to and use of medicines, as well as the level of knowledge of cardiovascular risk factors and compliance. INTRODUCTION: Low compliance has been one of the greatest challenges for the successful treatment of chronic diseases. Although this issue has been widely studied in patients with isolated hypertension, diabetes and dyslipidemia, compliance studies involving patients with these concomitant diseases or with metabolic syndrome diagnosis are scarce. METHODS: This was a cross-sectional study involving patients who have been diagnosed with metabolic syndrome according to the IDF criteria. Patients were being treated in a Health-Medical School Center bound to the Public Brazilian Healthcare System. This study was conducted in two phases. Phase I was characterized by analyzing medical records and Phase II involved interviewing the patients. A variation of the Morisky-Green Test was used to evaluate compliance. Compliance was the dependent variable and the independent variables included access to medicines, the use of medicines and the level of knowledge concerning cardiovascular risk factors. RESULTS: Two hundred and forty-three patients were identified as being eligible for Phase II, and 75 were included in the study. The average level of compliance was 5.44 points (standard deviation of 0.68), on a scale ranging from 1.00 to 6.00 points. There was no statistically meaningful association between independent variables and compliance. The level of patient knowledge of diet and dyslipidemia was considered to be low. CONCLUSIONS: Patients involved in this study exhibited a high level of compliance with drug treatment. Further research is needed to better elucidate the compliance behavior of patients who have been diagnosed with metabolic syndrome.