Endothelial function in humans. Studies of forearm resistance vessels.

We have demonstrated previously that inhibition of angiotensin-converting enzyme (ACE) with enalapril and angiotensin II blockade with losartan improve acetylcholine-dependent endothelial function in resistance vessels of patients with Type II diabetes. It was therefore of interest to examine the effect of losartan on conduit vessel function in this group. The influence of losartan (50 mg daily for 4 weeks) on endothelium-dependent and -independent vasodilator function was determined in 12 subjects with Type II diabetes using a randomized, double-blind, placebo-controlled crossover protocol. Conduit vessel endothelial function was assessed using high-resolution ultrasound and the brachial artery response to reactive hyperaemia (flow-mediated dilation; FMD); glyceryl trinitrate (GTN) was used as a non-endothelium-dependent dilator. Losartan administration significantly increased the FMD response from 5.2±0.7% (mean±S.E.M.) to 7.4±0.6% of vessel diameter (P < 0.05; paired t-test). There was no effect of losartan on the endothelium-independent responses to GTN (17.8±1.8% to 17.6±1.2%). Consistent with our previous findings in resistance vessels, administration of 50 mg of losartan daily improves NO-mediated dilation in the conduit vessels of subjects with Type II diabetes. Together with the findings that both ACE inhibition and angiotensin II blockade improve resistance vessel function in this group, it is likely that at least some of the beneficial effect is mediated through the angiotensin II/type 1 receptor pathway. A type 1 receptor antagonist seems a reasonable alternative to an ACE inhibitor to maintain conduit vessel endothelial function in Type II diabetic subjects.

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Effect of mild endurance exercise training and pravastatin on peripheral vasodilatation of forearm resistance vessels in patients with coronary artery disease

European Journal of Cardiovascular Prevention & Rehabilitation ◽

10.1097/01.hjr.0000173104.83732.ec ◽

2005 ◽

Vol 12 (4) ◽

pp. 332-340 ◽

Cited By ~ 9

Author(s):

Yves Allemann ◽

Christian Vetter ◽

Nesrin Kartal ◽

Stephan Eyer ◽

Svenia Marit Stengel ◽

...

Keyword(s):

Exercise Training ◽

Endothelial Function ◽

Statin Therapy ◽

Endurance Exercise ◽

Density Lipoprotein ◽

Vasomotor Function ◽

Cholesterol Levels ◽

Endurance Exercise Training ◽

Resistance Vessels ◽

Artery Disease

Background Improved endothelial function may contribute to the beneficial effects of cholesterol lowering therapy in patients with coronary artery disease (CAD), but results of the effect of statin therapy on endothelial function are disparate in these patients. Exercise training has been reported to improve endothelial function of patients at risk of or with established CAD. The goal of the study was to compare the effect of mild exercise training or statin therapy on forearm endothelial function in CAD patients with average cholesterol levels. Design and methods Twenty-eight sedentary male patients with angiographically documented CAD and average pretreatment total plasma cholesterol levels (5.1±0.9 mmol/l) aged 42–75 years were included. They were randomly assigned in a 2:1 order to either statin therapy (pravastatin, 40 mg daily) or exercise training therapy (mild endurance exercise three or more times a week). The effects of 10 weeks of either treatment on endothelium-dependent and independent vasodilation of forearm resistance vessels was assessed by plethysmography. Cardiopulmonary exercise testing was performed at baseline and after 10 weeks. Results Ten weeks of pravastatin therapy significantly reduced low-density lipoprotein cholesterol (from 3.8±0.6 to 3.1±0.6 mmol/l at study end, P=0.04) and the ratio of total to high-density lipoprotein cholesterol (from 4.9±0.8 to 3.7±0.7 mmol/l, P=0.002). Exercise training did not significantly modify the lipid profile. Peak oxygen consumption, maximal achieved workload and exercise duration tended to improve in the exercise training group but remained unchanged in the pravastatin-treated group. Neither 10 weeks of pravastatin nor mild endurance exercise training improved endothelium-dependent or independent vasomotor function in forearm resistance vessels. Conclusions In patients with CAD and average cholesterol levels, 10 weeks of treatment with mild endurance exercise training or with pravastatin failed to improve endothelium-dependent or independent vasomotor function in forearm resistance vessels.

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