High-density lipoprotein-cholesterol functionality and metabolic syndrome: Protocol for review and meta-analysis.

INTRODUCTION: The prevalence of metabolic syndrome (MetS) and MetS-related stroke is set to increase dramatically in coming decades. MetS is a complex disease that includes endothelial dysfunction, insulin resistance, diabetes, hypertension, ectopic obesity, and dyslipidaemia and an increased risk of cardiovascular events. One function of high-density lipoprotein (HDL) cholesterol (HDL-C) is the cholesterol-efflux pathway, which is the pathway where cholesterol is removed from macrophages within the arterial walls back into the bloodstream and out to the liver. As one of the key functions of HDL, their hypothesis was that if they could measure HDL-C-efflux capacity, they would have a better handle on the role of HDL in atherosclerosis. However, there are no systematic analyses or well-conducted meta-analyses to evaluate the relationship between HDL-C functionality and MetS. The aim of this study is to examine this association of HDL-C functionality with MetS in different ages and sex. METHODS AND ANALYSIS: The update systematic review and meta-analysis will be conducted using published studies that will be identified from electronic databases (i.e., PubMed, EMBASE, Web of Science, and Google Scholar). Studies that examined the association between HDL-C functionality and MetS; focused on cohort, case-control, and cross-sectional studies; were conducted among in adults aged 40 to 70 years; provided sufficient data for calculating odds ratio or relative risk with a 95% confidence interval; were published as original articles written in English or other languages; and have been published until January 2018 will be included. Study selection, data collection, quality assessment, and statistical syntheses will be conducted based on discussions among investigators. ETHICS AND DISSEMINATION: Ethics approval was not required for this study because it was based on published studies. The results and findings of this study will be submitted and published in a scientific peer-reviewed journal. TRIAL REGISTRATION NUMBER: PROSPERO (CRD42018083465).

High-density lipoprotein-cholesterol functionality and metabolic syndrome: Protocol for review and meta-analysis

INTRODUCTION: The prevalence of metabolic syndrome (MetS) and MetS-related stroke is set to increase dramatically in coming decades. MetS is a complex disease that includes endothelial dysfunction, insulin resistance, diabetes, hypertension, ectopic obesity, and dyslipidaemia and an increased risk of cardiovascular events. One function of high-density lipoprotein (HDL) cholesterol (HDL-C) is the cholesterol-efflux pathway, which is the pathway where cholesterol is removed from macrophages within the arterial walls back into the bloodstream and out to the liver. As one of the key functions of HDL, their hypothesis was that if they could measure HDL-C-efflux capacity, they would have a better handle on the role of HDL in atherosclerosis. However, there are no systematic analyses or well-conducted meta-analyses to evaluate the relationship between HDL-C functionality and MetS. The aim of this study is to examine this association of HDL-C functionality with MetS in different ages and sex. METHODS AND ANALYSIS: The update systematic review and meta-analysis will be conducted using published studies that will be identified from electronic databases (i.e., PubMed, EMBASE, Web of Science, and Google Scholar). Studies that examined the association between HDL-C functionality and MetS; focused on cohort, case-control, and cross-sectional studies; were conducted among in adults aged 40 to 70 years; provided sufficient data for calculating odds ratio or relative risk with a 95% confidence interval; were published as original articles written in English or other languages; and have been published until January 2018 will be included. Study selection, data collection, quality assessment, and statistical syntheses will be conducted based on discussions among investigators.

Statins in adult patients with HIV: Protocol for a systematic review and network meta-analysis.

BACKGROUND: Patients with HIV have been found to suffer from lipid abnormalities, including elevated levels of total and LDL-cholesterol as well as triglyceride levels. Abnormal lipid levels are associated with an increased risk of developing cardiovascular diseases, which are significant causes of mortality among the general population. Therefore, the objective of the current study is to conduct a systematic review with network meta-analysis to compare the effects of statins classes on HIV patients. METHODS: Randomized clinical trials (RCTs) and observational studies published in English up to 31 December 2017, and which include direct and/or indirect evidence, will be included. Studies will be retrieved by searching four electronic databases and cross-referencing. Dual selection and abstraction of data will occur. The primary outcome will all-cause mortality, new event of acute myocardial infarction, stroke (hemorrhagic and ischemic), hospitalization for acute coronary syndrome and urgent revascularization procedures and cardiovascular mortality. Secondary outcomes will be assessment of the differences in change of total cholesterol (TC), low-density lipoprotein (LDL-C), apolipoprotein B (ApoB), high density lipoprotein (HDL-C). Risk of bias will be assessed using the Cochrane Risk of Bias assessment instrument for RCTs and the Strengthening the Reporting of Observational Studies in Epidemiology instrument for observational studies. Network meta-analysis will be performed using multivariate random-effects meta-regression models. The surface under the cumulative ranking curve will be used to provide a hierarchy of statins that reduce cardiovascular mortality in HIV patients. A revised version of the Cochrane Risk of Bias tool (RoB 2.0) will be used to assess the risk of bias in eligible RCTs. Results will be synthesized and analyzed using network meta-analysis (NMA). Overall strength of the evidence and publication bias will be evaluated. Subgroup and sensitivity analysis will also be performed. RESULTS AND CONCLUSION: Ethics approval was not required for this study because it was based on published studies. The results and findings of this study will be submitted and published in a scientific peer-reviewed journal. The evidence will determine which combination of interventions are most promising for current practice and further investigation. TRIAL REGISTRATION NUMBER: PROSPERO (CRD42017072996).

Epicardial adipose tissue and carotid artery disease: Protocol for systematic review and meta-analysis.

BACKGROUND: Atherosclerosis is now widely recognized as a multifactorial disease with outcomes that arise from complex factors such as plaque components, blood flow, and inflammation. Epicardial adipose tissue (EAT) is a metabolically active fat depot, abundant in proinflammatory cytokines, and has been correlated with the extent and severity of carotid artery disease (CD). The locations most frequently affected by carotid atherosclerosis are the proximal internal carotid artery (ie, the origin) and the common carotid artery bifurcation. Progression of atheromatous plaque at the carotid bifurcation results in luminal narrowing, often accompanied by ulceration. However, there are no systematic analyses or well-conducted meta-analyses to evaluate the relationship between EAT and CD. The aim of this study is to examine this association of EAT with CD in different ages and sex. METHODS: This systematic review and meta-analysis will be conducted using published studies that will be identified from electronic databases (ie, PubMed, EMBASE, Web of Science, and Google Scholar. Studies that (1) examined the association between EAT and CD, (2) focus on cohort, case-control and cross-sectional studies, (3) will conducted among in adults aged 40 to 70 years, (4) provided sufficient data for calculating ORs or relative risk with a 95% CI, (5) will published as original articles written in English or other languages, and (6) have been published until January 2018 will be included. Study selection, data collection, quality assessment and statistical syntheses will be conducted based on discussions among investigators. RESULTS: We propose the current protocol to evaluate the evaluation of EAT with ED. CONCLUSION: This systematic review will not need ethical approval, because it does not involve human beings. The results and findings of this study will be submitted and published in a scientific peer-reviewed journal. ETHICS AND DISSEMINATION: Ethics approval was not required for this study because it was based on published studies. The results and findings of this study will be submitted and published in a scientific peer-reviewed journal. TRIAL REGISTRATION NUMBER: PROSPERO (CRD42018083458).

Epicardial adipose tissue and metabolic syndrome: An update protocol for systematic review and meta-analysis.

BACKGROUND: The prevalence of metabolic syndrome (MetS) and MetS-related stroke is set to increase dramatically in coming decades. MetS is a complex disease that includes endothelial dysfunction, insulin resistance, diabetes, hypertension, ectopic obesity, and dyslipidaemia, and an increased risk of cardiovascular events. However, there are no systematic analyses, or well-conducted meta-analyses to evaluate the relationship between epicardial adipose tissue (EAT) and (MetS). The aim of this study is to examine this association of EAT with MetS in different ages and sex. METHODS: The update systematic review, and meta-analysis will be conducted using published studies that will be identified from electronic databases (ie, PubMed, EMBASE, Web of Science, and Google Scholar. Studies that firstly, examined the association between EAT and MetS, secondly, focus on cohort, case-control, and cross-sectional studies, thirdly, were conducted among in adults aged between 40 and 70 years, fourth, provided sufficient data for calculating ORs or relative risk with a 95% CI, fifth, were published as original articles written in English or other languages, and sixth, have been published until January year 2018 will be included. Study selection, data collection, quality assessment, and statistical syntheses will be conducted based on discussions among investigators. RESULTS: Ethics approval was not required for this study because it was based on published studies. The results and findings of this study will be submitted and published in a scientific peer-reviewed journal. This study will provide a high quality synthesis on the association of EAT and MetS. CONCLUSION: This systematic review will provide evidence to assess whether there is a strong association of EAT and MetS, and its components.

Metabolic syndrome and risk of stroke: Protocol for an update systematic review and meta-analysis.

INTRODUCTION: The metabolic syndrome is composed of several cardiovascular risk factors and has a high prevalence throughout the world. However, there are no systematic analyses or well-conducted meta-analyses to evaluate the relationship between metabolic syndrome and stroke. The aim of this study is to examine this association of metabolic syndrome with stroke in different ages and sex. METHODS AND ANALYSIS: The update systematic review and meta-analysis will be conducted using published studies that will be identified from electronic databases (i.e., PubMed, EMBASE, Web of Science, and Google Scholar. Studies that examined the association between metabolic syndrome and stroke, had a longitudinal or prospective cohort design, were conducted among in adults aged 40 to 70 years, provided sufficient data for calculating ORs or relative risk with a 95% CI, were published as original articles written in English or other languages, and have been published until December 2017 will be included. Study selection, data collection, quality assessment, and statistical syntheses will be conducted based on discussions among investigators. ETHICS AND DISSEMINATION: Ethics approval was not required for this study because it was based on published studies. The results and findings of this study will be submitted and published in a scientific peer-reviewed journal. The findings from this study could be useful for assessing metabolic syndrome risk factors in stroke, and determining approaches for prevention of stroke in the future.

Epicardial adipose tissue and metabolic syndrome An update protocol for systematic review and meta-analysis

BACKGROUND: The prevalence of metabolic syndrome (MetS) and MetS-related stroke is set to increase dramatically in coming decades. MetS is a complex disease that includes endothelial dysfunction, insulin resistance, diabetes, hypertension, ectopic obesity, and dyslipidaemia, and an increased risk of cardiovascular events. However, there are no systematic analyses, or well conducted meta-analyses to evaluate the relationship between epicardial adipose tissue (EAT) and (MetS). The aim of this study is to examine this association of EAT with MetS in different ages and sex. METHODS: The update systematic review, and meta-analysis will be conducted using published studies that will be identified from electronic databases (ie, PubMed, EMBASE, Web of Science, and Google Scholar. Studies that firstly, examined the association between EAT and MetS, secondly, focus on cohort, case-control, and cross-sectional studies, thirdly, were conducted among in adults aged between 40 and 70 years, fourth, provided sufficient data for calculating ORs or relative risk with a 95% CI, fifth, were published as original articles written in English or other languages, and sixth, have been published until January year 2018 will be included. Study selection, data collection, quality assessment, and statistical syntheses will be conducted based on discussions among investigators. RESULTS: Ethics approval was not required for this study because it was based on published studies. The results and findings of this study will be submitted and published in a scientific peer-reviewed journal. This study will provide a high quality synthesis on the association of EAT and MetS. CONCLUSION: This systematic review will provide evidence to assess whether there is a strong association of EAT and MetS, and its components.

Statins in adult patients with HIV Protocol for a systematic review and network meta-analysis

BACKGROUND: Patients with HIV have been found to suffer from lipid abnormalities, including elevated levels of total and LDL cholesterol as well as triglyceride levels. Abnormal lipid levels are associated with an increased risk of developing cardiovascular diseases, which are significant causes of mortality among the general population. Therefore, the objective of the current study is to conduct a systematic review with network meta-analysis to compare the effects of statins classes on HIV patients. METHODS: Randomized clinical trials (RCTs) and observational studies published in English up to 31 December 2017, and which include direct and/or indirect evidence, will be included. Studies will be retrieved by searching four electronic databases and cross referencing. Dual selection and abstraction of data will occur. The primary outcome will all-cause mortality, new event of acute myocardial infarction, stroke (hemorrhagic and ischemic), hospitalization for acute coronary syndrome and urgent revascularization procedures and cardiovascular mortality. Secondary outcomes will be assessment of the differences in change of total cholesterol (TC), low-density lipoprotein (LDL-C), apolipoprotein B (ApoB), high density lipoprotein (HDL-C). Risk of bias will be assessed using the Cochrane Risk of Bias assessment instrument for RCTs and the Strengthening the Reporting of Observational Studies in Epidemiology instrument for observational studies. Network meta-analysis will be performed using multivariate random-effects meta-regression models. The surface under the cumulative ranking curve will be used to provide a hierarchy of statins that reduce cardiovascular mortality in HIV patients. A revised version of the Cochrane Risk of Bias tool (RoB 2.0) will be used to assess the risk of bias in eligible RCTs. Results will be synthesized and analyzed using network meta-analysis (NMA). Overall strength of the evidence and publication bias will be evaluated. Subgroup and sensitivity analysis will also be performed. RESULTS AND CONCLUSION: Ethics approval was not required for this study because it was based on published studies. The results and findings of this study will be submitted and published in a scientific peer-reviewed journal. The evidence will determine which combination of interventions are most promising for current practice and further investigation.

Epicardial adipose tissue and carotid artery disease Protocol for systematic review and meta-analysis

BACKGROUND: Atherosclerosis is now widely recognized as a multifactorial disease with outcomes that arise from complex factors such as plaque components, blood flow, and inflammation. Epicardial adipose tissue (EAT) is a metabolically active fat depot, abundant in proinflammatory cytokines, and has been correlated with the extent and severity of carotid artery disease (CD). The locations most frequently affected by carotid atherosclerosis are the proximal internal carotid artery (ie, the origin) and the common carotid artery bifurcation. Progression of atheromatous plaque at the carotid bifurcation results in luminal narrowing, often accompanied by ulceration. However, there are no systematic analyses or well-conducted meta-analyses to evaluate the relationship between EAT and CD. The aim of this study is to examine this association of EAT with CD in different ages and sex. METHODS: This systematic review and meta-analysis will be conducted using published studies that will be identified from electronic databases (ie, PubMed, EMBASE, Web of Science, and Google Scholar. Studies that (1) examined the association between EAT and CD, (2) focus on cohort, case-control and cross-sectional studies, (3) will conducted among in adults aged 40 to 70 years, (4) provided sufficient data for calculating ORs or relative risk with a 95% CI, (5) will published as original articles written in English or other languages, and (6) have been published until January 2018 will be included. Study selection, data collection, quality assessment and statistical syntheses will be conducted based on discussions among investigators. Results: We propose the current protocol to evaluate the evaluation of EAT with ED. CONCLUSION: This systematic review will not need ethical approval, because it does not involve human beings. The results and findings of this study will be submitted and published in a scientific peer-reviewed journal.

Metabolic syndrome and risk of stroke Protocol for an update systematic review and meta-analysis

INTRODUCTION: The metabolic syndrome is composed of several cardiovascular risk factors and has a high prevalence throughout the world. However, there are no systematic analyses or well-conducted meta-analyses to evaluate the relationship between metabolic syndrome and stroke. The aim of this study is to examine this association of metabolic syndrome with stroke in different ages and sex. METHODS AND ANALYSIS: The update systematic review and meta-analysis will be conducted using published studies that will be identified from electronic databases (i.e., PubMed, EMBASE, Web of Science, and Google Scholar. Studies that examined the association between metabolic syndrome and stroke, had a longitudinal or prospective cohort design, were conducted among in adults aged 40 to 70 years, provided sufficient data for calculating ORs or relative risk with a 95% CI, were published as original articles written in English or other languages, and have been published until December 2017 will be included. Study selection, data collection, quality assessment, and statistical syntheses will be conducted based on discussions among investigators.

Abdominal Obesity and Association With Atherosclerosis Risk Factors: The Uberlândia Heart Study.

Ectopic visceral fat (VF) and subcutaneous fat (SCF) are associated with cardiovascular risk factors. Gender differences in the correlations of cardiovascular disease risk factors and ectopic fat in the Brazilian population still lacking. Cross-sectional study with 101 volunteers (50.49% men; mean age 56.5 ±â€Š18, range 19-74 years) drawn from the Uberlândia Heart Study underwent ultrasonography assessment of abdominal visceral adipose tissue with convex transducer of 3.5 MHz of frequency. The thickness of VF was ultrasonographically measured by the distance between the inner face of the abdominal muscle and the posterior face of abdominal aorta, 1 cm above the umbilicus. The SCF thickness was measured with a 7.5 MHz linear transducer transversely positioned 1 cm above the umbilical scar. The exams were always performed by the same examiner. Ectopic fat volumes were examined in relation to waist circumference, blood pressure, and metabolic risk factors. The VF was significantly associated with the levels of triglycerides (P < 0.01, r = 0.10), HDL cholesterol (P < 0.005, r = 0.15), total cholesterol (P < 0.01, r = 0.10), waist circumference (P < 0.0001, r = 0.43), systolic blood pressure (P < 0.001, r = 0.41), and diastolic blood pressure (P < 0.001, r = 0.32) in women, and with the levels of triglycerides (P < 0.002, r = 0,14), HDL cholesterol (P < 0.032, r = 0.07), glucose (P < 0.001, r = 0.15), alanine aminotransferase (ALT) (P < 0.008, r = 0.12), gamma-GT (P < 0.001, r = 0.30), waist circumference (P < 0.001, r = 0.52), systolic blood pressure (P < 0.001, r = 0.32), and diastolic blood pressure (P < 0.001, r = 0.26) in men. SCF was significantly associated with the levels of triglycerides (P < 0.01, r = 0.34), LDL cholesterol (P < 0.001, r = 0.36), total cholesterol (P < 0.05, r = 0.36), waist circumference (P < 0.0001, r = 0.62), systolic and diastolic blood pressure (P < 0.05, r = 0.34) in women, and with the waist circumference (P < 0.001, r = 0.065)), and MetS (P < 0.05, r = 0.11) in men. The VF and SCF were correlated with most cardiovascular risk factors in both genders but our findings support the idea that there are gender differences in the correlations between ectopic fat deposition and the cardiovascular risk factors.

Perirenal Fat and Association With Metabolic Risk Factors: The Uberlândia Heart Study.

Perirenal fat (PRF) is associated with cardiovascular risk factors. Gender differences in the correlations of cardiovascular disease risk factors and PRF in the Brazilian population are lacking.Cross-sectional study with 101 (50.49% men; mean age 56.5 ±â€Š18, range 19-74 years) drawn from the Uberlândia Heart Study underwent ultrasonography assessment of abdominal adipose. For the PRF, a 3.5 MHz transducer was measured in the middle third of the right kidney, with the transducer positioned at the axillary midline. The examinations were always performed by the same examiner. The PRF thickness was examined in relation to waist circumference, blood pressure, and metabolic risk factors. The PRF was significantly associated with the levels of gamma-glutamyl transferase (P < 0.05, r = 0.08), fasting plasma glucose (P < 0.05, r = 0.07), waist circumference (P < 0.05, r = 0.10), and metabolic syndrome (P < 0.001, r = 0.38) in men, and with the levels of fasting plasma glucose (P < 0.05) in women.The PRF was correlated with most cardiovascular risk factors in men and only in glucose at the women.

Cardiac tumors: a brief commentary.

Patients with cardiac tumors may present with cardiovascular related or constitutional symptoms, but more often than not a cardiac mass is discovered incidentally during an imaging examination performed for an unrelated indication. Cardiac myxoma is generally considered to be a surgical emergency. Echocardiography, including the transesophageal approach, is the most important means of diagnosis; computed tomography and magnetic resonance imaging. The clinical presentation has changed, and the management of cardiac myxoma now needs to be reviewed.

HDL disfuncionante e o endoltélio / Dysfunctional HDL and the endothelium

o endotélio saudável produz e libera numerosos autacoides, entreos quais o óxido nítrico, elemento que imprime no tônus vascularcaracterísticas francamente vasodilatadoras, mantendo a homeostasevascular por meio dos seus efeitos anti-aterogênicos e antitrombóticos.Algumas doenças cardiovasculares como hipertensão arterial,diabetes mellitus e dislipidernias provocam uma disfunção endotelial,levando a uma modificação do estado normal de vasodilataçãoendotélio-dependente resultante de uma diminuição da biodisponibilidadedo óxido nítrico. Colesterol da lipoproteína de alta densidade(HDL-C) e lipoproteína de alta densidade (HDL) não são sinônimose existe uma clara distinção entre eles. O HDL-C é o colesterol queé carreado pelas partículas de HDL, as quais existem em um númerosuperior a uma dezena de subfrações, cada uma com diferentescomposições. As partículas de HDL possuem propriedades biológicasateroprotetoras, como o transporte reverso do colesterol, e recentementefoi descoberto que também agem diretamente no endotélio, auxiliandoa modular a vasodilatação endotélio dependente. Estas propriedadesdas partículas de HDL estão comprometidas em doenças comodislipidemias, síndrome metabólica e diabetes mellitus porque elasperdem a sua eficiência funcional por sofrerem alterações estruturais,tornando-se disfuncionantes. Em pacientes com estas doenças,observou-se que a presença de partículas HDL disfuncionantes influencia diretamente uma menor produção de óxido nítrico peloendotélio, levando a vasculatura a um estado preponderantementevasoconstritor. Exercício físico e alguns fármacos podem melhorar aFuncionabilidade das partículas de HDL, que agindo diretamente nascélulas endoteliais aumentam a liberação de óxido nítrico e melhoramo estado de vasodilatação endotélio-dependente...

The healthy endothelium produces and releases numerousautacoids, including nitric oxide, fundamental element inmaintaining vascular homeostasis through its anti-thromboticand anti-atherogenic properties. Certain cardiovascular diseasessuch as hypertension, diabetes mellitus and dyslipidernia causeendothelial dysfunction, leading to a change in the state of normalendotheli um-dependent vasodilation, caused by a decrease in thebioavailabi lity of nitric oxide. High density lipoprotein cholesterol(HDL-C) and high density lipoprotein (HDL) are not synonymousand there is a c1ear distinction between them. HDL-C is thecholesterol carried by HDL particles, which are in a number higherthan a dozen sub-fractions, each with different compositions.HDL particles have many biological properties, such as reversecholesterol transport, and it has recently been discovered that theseparticles also act directly on the endothelium helping in modulateendothelium-dependent vasodilation. These properties ofHDL areimpaired in diseases such as dyslipidemia, metabolic syndromeand diabetes mellitus because they lose their functional efficacy toundergo structural changes, becoming dysfunctional. In patientswith these diseases the presence of dysfunctional HDL particlesdirectly inftuences a lower production of nitric oxide by theendothelium, leading the vasculature to a condition predominantlyvasoconstrictor. Physical exerci se and some agents may improvethe functionality of HDL that acts directly on the endothelialcells increasing the release of nitric oxide and improving theendothelium-dependent vasodilation state...

Effect of exercise training on plasma levels and functional properties of high-density lipoprotein cholesterol in the metabolic syndrome.

Intense lifestyle modifications can change the high-density lipoprotein (HDL) cholesterol concentration. The aim of the present study was to analyze the early effects of short-term exercise training, without any specific diet, on the HDL cholesterol plasma levels and HDL functional characteristics in patients with the metabolic syndrome (MS). We studied 30 sedentary subjects, 20 with and 10 without the MS. The patients with the MS underwent moderate intensity exercise training for 3 months on bicycle ergometers. Blood was sampled before and after training for biochemical analysis, paraoxonase-1 activity, and HDL subfraction composition and antioxidative capacity. Lipid transfer to HDL was assayed in vitro using a labeled nanoemulsion as the lipid donor. At baseline, the MS group had greater triglyceride levels and a lower HDL cholesterol concentration and lower paraoxonase-1 activity than did the controls. Training decreased the plasma triglycerides but did not change the low-density lipoprotein or HDL cholesterol levels. Nonetheless, exercise training increased the HDL subfractions' antioxidative capacity and paraoxonase-1 activity. After training, the MS group had compositional changes in the smallest HDL subfractions associated with increased free cholesterol and cholesterol ester transfers to HDL, reaching normal values. In conclusion, the present investigation has added relevant information about the dissociation between the quantitative and qualitative aspects of HDL after short-term exercise training without any specific diet in those with the MS, highlighting the importance of evaluating the functional aspects of the lipoproteins, in addition to their plasma levels.

Asymmetric dimethylarginine (ADMA) and endothelial dysfunction: implications for atherogenesis.

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.

Increased circulating levels of matrix metalloproteinase (MMP)-8, MMP-9, and pro-inflammatory markers in patients with metabolic syndrome.

BACKGROUND: Metabolic syndrome (MetS) predisposes to cardiovascular complications. Increased concentrations of pro-inflammatory mediators and imbalanced concentrations of matrix metalloproteinases (MMPs) and their inhibitors (TIMPs) may reflect the pathophysiology of MetS. We compared the circulating levels of MMPs, TIMPs, and inflammatory mediators in MetS patients with those found in healthy controls. METHODS: We studied 25 healthy subjects and 25 MetS patients. The plasma levels of pro-MMP-2 and pro-MMP-9 were determined by gelatin zymography. The plasma concentrations of MMP-8, MMP-3, TIMP-1, TIMP-2, monocyte chemoattractant protein-1 (MCP-1), interleukin-6 (IL-6), intercellular adhesion molecule (sICAM-1), and sP-selectin were measured by ELISA kits. RESULTS: We found higher sP-selectin, sICAM-1, MCP-1, and IL-6 (all P<0.05) concentrations in MetS patients compared with healthy controls. No differences in pro-MMP-2, MMP-3, and TIMP-2 levels were found (all P>0.05). However, we found higher pro-MMP-9, MMP-8, and TIMP-1 levels in MetS patients compared with healthy controls (all P<0.05). CONCLUSIONS: Patients with MetS have increased circulating concentrations of pro-MMP-9, MMP-8, and TIMP-1 that are associated with increased concentrations of pro-inflammatory mediators and adhesion molecules. These findings suggest that MMPs may have a role in the increased cardiovascular risk of MetS patients. Pharmacological interventions targeting MMPs, especially MMP-9 and MMP-8 deserve further investigation in MetS patients.

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.