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Flow-mediated Dilatation (flow-mediated + dilatation)

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Medical Sciences	100%

Selected Abstracts

Advanced oxidative protein products are independently associated with endothelial function in peritoneal dialysis patients

NEPHROLOGY, Issue 3 2009
HUSEYIN KOCAK
SUMMARY Aim: Oxidative stress (OS) and asymmetric dimethylarginine (ADMA) are accepted as non-classical cardiovascular risk factors in end-stage renal disease patients. To clarify the role of these factors in the atherosclerotic process, we investigated if OS and ADMA are associated with endothelial function (EF) in peritoneal dialysis (PD) patients. Methods: Fifty-two non-diabetic PD patients without known atherosclerotic disease as well as 30 age- and sex-matched healthy individuals were included. We measured serum thiobarbituric acid-reactive substances (TBARS), malondialdehyde (MDA), advanced glycation end-product (AGE), pentosidine, advanced oxidation protein products (AOPP), ADMA and EF as described by Celermejer et al. in all subjects. Results: TBARS, MDA, AOPP, AGE, pentosidine and ADMA levels were significantly higher in PD patients than in controls (P < 0.001). Flow-mediated dilatation (FMD)% and nitrate mediated dilatation (NMD)% in PD patients were lower than in the control group (7.7 ± 4.0% vs 11.70 ± 5.50%, P < 0.01 and 17.6 ± 8.3% vs 26.4 ± 4.6%, P < 0.01). Additionally, it was found that AOPP are independently correlated with FMD% and NMD% in PD patients (, = ,463, P < 0.01 and , = ,420, P < 0.05). Conclusion: This study shows that PD patients without known atherosclerotic disease can also be characterized by endothelial dysfunction and AOPP levels independently predict endothelial function level in PD patients. [source]

Statin therapy improves brachial artery vasodilator function in patients with Type 1 diabetes and microalbuminuria

DIABETIC MEDICINE, Issue 3 2005
G. K. Dogra
Abstract Aims Type 1 diabetes mellitus patients with microalbuminuria have endothelial dysfunction associated with the degree of albuminuria but not with LDL-cholesterol levels. Lipid-lowering agents such as statins may still be of benefit as they can correct endothelial dysfunction by both lipid and non-lipid mechanisms. We therefore examined the effects of atorvastatin on brachial artery endothelial dysfunction in these patients. Methods In a double-blind, randomized crossover study, 16 Type 1 diabetes mellitus patients with microalbuminuria received 6 weeks of atorvastatin 40 mg/day or placebo, separated by a 4-week washout. Brachial artery, endothelium-dependent, flow-mediated dilatation (FMD) and endothelium-independent, glyceryl trinitrate-mediated dilatation (GTNMD) were measured. Results Compared with placebo, atorvastatin produced a significant decrease in apolipoprotein B (34.2%), LDL-cholesterol (44.1%) (all P < 0.001), and oxidized-LDL (35.7%, P = 0.03). There was a non-significant increase in plasma cGMP (P = 0.13) on atorvastatin. FMD and GTNMD increased significantly on atorvastatin (FMD: atorvastatin +1.8 ± 0.4%; placebo +0.2 ± 0.4%, P = 0.007); (GTNMD: atorvastatin +1.3 ± 0.9%; placebo ,1.2 ± 0.6%, P = 0.04). An increase in cGMP was independently correlated with an increase in FMD on atorvastatin (adjusted R2 0.41, P = 0.02). Conclusion Atorvastatin improves endothelium-dependent and independent vasodilator function of the brachial artery in Type 1 diabetes mellitus patients with microalbuminuria. This may relate to pleiotropic effects of statins, in particular reduced oxidative stress and increased availability of nitric oxide. [source]

"Supranormal" Cardiac Function in Athletes Related to Better Arterial and Endothelial Function

ECHOCARDIOGRAPHY, Issue 6 2010
Maria Florescu M.D.
Objective: Athlete's heart is associated with left ventricular (LV) hypertrophy (LVH), and "supranormal" cardiac function, suggesting that this is a physiological process. Hypertrophy alone cannot explain increase in cardiac function, therefore, other mechanisms, such as better ventriculo-arterial coupling might be involved. Methods: We studied 60 male (21 ± 3 years) subjects: 27 endurance athletes, and a control group of 33 age-matched sedentary subjects. We assessed global systolic and diastolic LV function, short- and long-axis myocardial velocities, arterial structure and function and ventriculo-arterial coupling, endothelial function by flow-mediated dilatation, and amino-terminal pro-brain natriuretic peptide (NT-proBNP) and biological markers of myocardial fibrosis and of oxidative stress. Results: Athletes had "supranormal" LV longitudinal function (12.4 ± 1.0 vs 10.1 ± 1.4 cm/s for longitudinal systolic velocity, and 17.4 ± 2.6 vs 15.1 ± 2.4 cm/s for longitudinal early diastolic velocity, both P < 0.01), whereas ejection fraction and short-axis function were similar to controls. Meanwhile, they had better endothelial function (16.7 ± 7.0 vs 13.3 ± 5.3%, P < 0.05) and lower arterial stiffness (pulse wave velocity 7.1 ± 0.6 vs 8.8 ± 1.1 m/s, P = 0.0001), related to lower oxidative stress (0.259 ± 0.71 vs 0.428 ± 0.88 nmol/mL, P = 0.0001), with improved ventriculo-arterial coupling (37.1 ± 21.5 vs 15.5 ± 13.4 mmHg.m/s3× 103, P = 0.0001). NT-proBNP and markers of myocardial fibrosis were not different from controls. LV longitudinal function was directly related to ventriculo-arterial coupling, and inversely related to arterial stiffness and to oxidative stress. Conclusions: "Supranormal" cardiac function in athletes is due to better endothelial and arterial function, related to lower oxidative stress, with optimized ventriculo-arterial coupling; athlete's heart is purely a physiological phenomenon, associated with "supranormal" cardiac function, and there are no markers of myocardial fibrosis. (Echocardiography 2010;27:659-667) [source]

Clinical methods for the evaluation of endothelial function , a focus on resistance arteries

FUNDAMENTAL & CLINICAL PHARMACOLOGY, Issue 3 2006
Robinson Joannides
Abstract Endothelial dysfunction is a key event in the pathophysiology of cardiovascular diseases and appears as a strong independent predictor of cardiovascular events. In this context, biological evaluation of endothelial circulating markers can be helpful. However, functional tests using pharmacological stimuli appear more specific for the study of resistance arteries. These methods consist in the evaluation of the endothelium-dependent changes in regional vascular flow in response to local infusion of substances that act through endothelial receptors without modification of systemic arterial pressure and in comparison with a non endothelium-dependent relaxation. Flow is measured by Doppler and intravascular ultrasound in coronary circulation, laser Doppler in skin and by venous occlusion plethysmography in peripheral muscular arteries. Similar studies can be performed ex vivo using isolated resistance arteries obtained from fat subcutaneous biopsies. In addition, other information can be obtained from reactive hyperemia and the study of the flow-mediated dilatation of conduit arteries to enable a selective and comprehensive approach of the heterogeneity of endothelial function in pathophysiology. [source]