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1. Hypertension is associated with a distension of the large arteries and consequently a marked reduction in arterial compliance, which does not result merely from the mechanical effects of elevated arterial pressure but also from early functional and/or structural changes in the arterial walls. This suggests that one of the aims of antihypertensive therapy should be to reverse these arterial abnormalities in the hope of protecting the patient from the atherosclerotic complications of hypertension. 2. Studies have been carried out to compare the effects of equieffective antihypertensive doses of pindolol and propranolol on the arterial circulation in patients suffering from essential hypertension. After 3 months therapy pindolol produced a dilatation of the brachial artery with an increase in arterial compliance and blood flow. In contrast, propranolol, despite comparable antihypertensive effects, did not influence brachial artery circulation. 3. These different effects on the arterial circulation presumably reflect the differing pharmacological properties of the two beta-adrenoceptor antagonists and suggest that the intrinsic sympathomimetic activity of pindolol may be responsible for the qualitative differences in the arterial responses to the two drugs. 4. The results reviewed here reveal that even when two drugs of the same class are used to treat patients with essential hypertension the effects of these agents on arterial haemodynamics can vary greatly and are unrelated to the degree of blood pressure lowering. Thus, pindolol, in contrast to propranolol, not only lowers blood pressure but also reverses some of the changes in arterial haemodynamics which are characteristic of hypertensive disease.(ABSTRACT TRUNCATED AT 250 WORDS) [ABSTRACT FROM AUTHOR]

The haemodynamic pattern of the common carotid artery was studied in men with sustained essential hypertension using pulsed Doppler methods before and after administration of vasodilating drugs. Captopril produced both a fall in vascular resistance and an increase in arterial diameter of the common carotid artery. Isosorbide dinitrate increased markedly the arterial diameter but did not change vascular resistance. Nitrendipine decreased vascular resistance with no change in the arterial diameter. In the common carotid circulation of patients with essential hypertension, vasodilating drugs may either dilate small arteries (nitrendipine), large arteries (isosorbide dinitrate), or both (captopril). [ABSTRACT FROM AUTHOR]

By using simultaneous recording curves obtained with pulsed Doppler velocimetry and strain gauge mechanography, forearm arterial haemodynamics were studied in 26 patients with mild to moderate essential hypertension. Fifteen patients received a single oral dose of nicardipine 40 mg, and 11 patients were treated with nicardipine 30 mg three times daily for 3 months. In both groups of patients there was a similar and significant (P less than 0.001) reduction in mean, systolic, and diastolic pressures. There was a slight increase in heart rate (P less than 0.05) after the single dose, but no change after 3 months of treatment. The diameter, blood velocity, and blood flow of the brachial artery increased significantly in both treatment groups. The decrease in forearm vascular resistance was significant for both treatment groups. Brachial artery compliance increased (P less than 0.01) and characteristic impedance decreased (P less than 0.01) after both single-dose and long-term therapy with nicardipine. In patients who received nicardipine for 3 months, there were close correlations between the baseline serum calcium level and the percent change in vascular resistance (r = -0.73, P less than 0.01), blood flow (r = 0.89, P less than 0.001), and blood velocity (r = 0.91. P less than 0.001) of the forearm. No correlation was found between the baseline serum calcium and the change in arterial pressure. This study provided evidence that the blood-pressure-lowering effect of nicardipine was accompanied by a direct vasodilatory action in the small and large arteries of the forearm. An increase in peripheral blood flow with concomitant improvement of arterial compliance are the consequences of these arterial actions. [ABSTRACT FROM AUTHOR]

Brachial artery haemodynamics, including arterial diameter, blood flow velocity, blood flow and compliance of the brachial artery may be evaluated non-invasively in man, using pulsed Doppler methods. In patients with sustained untreated essential hypertension, brachial artery diameter is increased, blood flow is normal and arterial compliance is reduced independently of the level of blood pressure. Converting enzyme inhibition may reverse the large artery abnormalities, causing an increase in arterial diameter, blood flow and arterial compliance both in acute and long-term investigations. These changes in large arteries may contribute towards improved cardiovascular morbidity and less mortality in treated hypertensive patients. [ABSTRACT FROM AUTHOR]

1 Blood pressure, systemic arterial compliance, and diameter, blood flow velocity, volumic flow and impedance of the brachial artery were measured before and after intravenous administration of nitroglycerin (15 micrograms/min during 15 min) in 11 patients with sustained essential hypertension. 2 For the evaluation of the diameter of the brachial artery, a bidimensional pulsed Doppler was used, enabling the angle of the ultrasound beam relative to the flowing stream of blood to be measured with an error of less than 2%. 3 After nitroglycerin, systolic pressure significantly decreased (P less than 0.01) without significant change in diastolic and mean arterial pressures, cardiac index, stroke index and total peripheral resistance. 4 Systemic arterial compliance and brachial artery diameter significantly increased (P less than 0.001; P less than 0.01) while velocity and blood flow of the brachial artery were unchanged. 5 The pattern of the input impedance of the brachial artery was consistent with a predominant effect of nitroglycerin on the viscoelastic properties of peripheral large arteries. 6 The study provided evidence that, in hypertensive patients, nitroglycerin has a direct effect on peripheral large arteries, causing an increase in arterial diameter and compliance, thus leading to a predominant decrease in systolic pressure. [ABSTRACT FROM AUTHOR]

Patients with type 2 diabetes mellitus using sulfonylurea derivatives or insulin may experience hypoglycaemia. However, recent data regarding the incidence of hypoglycaemia are scarce. We conducted a systematic review and meta-analysis to determine the proportion of patients with type 2 diabetes mellitus that experience hypoglycaemia when treated with sulfonylurea or insulin. We searched MEDLINE and EMBASE for randomized controlled trials that compared incretin-based drugs to sulfonylureas or insulin and assessed hypoglycaemia incidence in the latter therapies. Subgroup and meta-regression analyses were performed to study possible associations with potential risk factors for hypoglycaemia. Data of 25 studies were extracted, 22 for sulfonylurea and 3 for insulin. Hypoglycaemia with glucose ≤3.1 mmol/L or ≤2.8 mmol/L was experienced by 10.1% [95% confidence interval (CI) 7.3-13.8%] and 5.9% (95% CI 2.5-13.4%) of patients with any sulfonylurea treatment. Severe hypoglycaemia was experienced by 0.8% (95% CI 0.5-1.3%) of patients. Hypoglycaemia with glucose ≤3.1 mmol/L and severe hypoglycaemia occurred least frequently with gliclazide: in 1.4% (95% CI 0.8-2.4%) and 0.1% (95% CI 0-0.7%) of patients, respectively. None of the risk factors were significant in a stepwise multivariate meta-regression analysis. Too few studies had insulin as comparator, so these data could not be meta-analysed. The majority of patients with type 2 diabetes mellitus on sulfonylurea therapy in clinical trials remain free of any relevant hypoglycaemia. Gliclazide was associated with the lowest risk of hypoglycaemia. Because participants in randomized controlled trials differ from the general population, care should be taken when translating these data into clinical practice., (Copyright © 2013 John Wiley & Sons, Ltd.)

Arteriovenous fistula (AVF) blood flow was evaluated in 32 dialysis patients using a pulsed Doppler velocimeter with two dominant features: a range-gated time system and a double transducer probe. With the proposed apparatus, the observation angle between the ultrasound beam and the vessel axis was known. In radial AVF, blood flow was 728 +/- 53 ml/min and was negatively correlated with the age of the AVF (r = -0.62; p less than 0.01). In brachial AVF, blood flow was 778 +/- 152 ml/min. In bovine heterograft AVF, blood flow was 1,225 +/- 125 ml/min. In the overall population, a negative relationship was observed between the diameter of the fistula and the blood flow velocity (r = -0.57; p less than 0.01). The study describes an accurate noninvasive method for the determination of fistula blood flow in dialysis patients, which may be helpful in the follow-up of the regional hemodynamics of this vascular access.