Andrew Zambanini

Injection related anxiety in insulin-treated diabetes

The presence of injection related anxiety and phobia may influence compliance, glycaemic control and quality of life in patients with insulin-treated diabetes. Unselected consecutive, insulin-treated patients attending a diabetes clinic for follow-up, completed a standardised questionnaire providing an injection anxiety score (IAS) and general anxiety score (GAS). A total of 115 insulin-treated (80 Type 1 and 35 Type 2) diabetic patients completed the questionnaire. Injections had been avoided secondary to anxiety in 14% of cases and 42% expressed concern at having to inject more frequently. An IAS > or = 3 was seen in 28% of patients and of these, 66% injected insulin one to two times/day, 45% had avoided injections, and 70% would be bothered by more frequent injections. A significant correlation between IAS and GAS was seen (Kendalls tau-a 0.30, 95% CI 0.19-0.41, P < 0.001). GAS was significantly associated with both previous injection avoidance and expressed concern at increased injection frequency. No significant correlation was seen with HbA1c and injection or general anxiety scores. Symptoms relating to insulin injection anxiety and phobia have a high prevalence in an unselected group of diabetic patients requiring insulin injections and are associated with higher levels of general anxiety.

Differences in the Magnitude of Wave Reflection Account for Differential Effects of Amlodipine- Versus Atenolol-Based Regimens on Central Blood Pressure An Anglo-Scandinavian Cardiac Outcome Trial Substudy

Antihypertensive agents may differ in their effects on central systolic blood pressure, and this may contribute to treatment-related differences in cardiovascular outcomes. In a substudy of the Anglo-Scandinavian Cardiac Outcome Trial, we investigated whether directly measured carotid systolic blood pressure differed between people randomized to amlodipine- and atenolol-based therapies and whether this is accounted for by differences in wave reflection patterns. Additional analysis was undertaken to establish whether differences in carotid systolic blood pressure predicted left ventricular mass, accounting for between-treatment differences in left ventricular mass index. Blood pressure and flow velocity were measured in the right carotid artery of 259 patients. Wave intensity analysis was used to separate and quantify forward and backward waves. Brachial blood pressure did not differ significantly between groups, but carotid systolic blood pressure (127 [12] versus 133 [15] mm Hg; P<0.001), the ratio of backward:forward pressure (0.48 [0.17] versus 0.53 [0.19]; P=0.01), and wave reflection index (19.8% [10.9%] versus 23.3% [13.3%]; P=0.02) were significantly lower in patients randomized to amlodipine-based therapy. Left ventricular mass index was also lower in this group, and adjustment for carotid blood pressure attenuated treatment differences to a greater extent than brachial blood pressure. Carotid systolic blood pressure was also a significant independent predictor of left ventricular mass index in a multivariate model. Carotid systolic blood pressure is lower in people randomized to amlodipine-based compared with atenolol-based treatment despite there being no significant difference in brachial blood pressure. This difference is attributable to a lesser magnitude of wave reflection in patients randomized to the amlodipine-based regimen.

Candesartan- and atenolol-based treatments induce different patterns of carotid artery and left ventricular remodeling in hypertension.

Background and Purpose— Angiotensin receptor blocker (ARB)–based treatment reduces cardiovascular events and stroke more than does β-blocker–based treatment despite similar blood pressure (BP) reduction. We investigated whether these treatments have different effects on cardiac and large-artery remodelling and evaluated the relation of arterial remodelling to hemodynamic changes in subjects with hypertension. Methods— We compared the treatment effects of an ARB (candesartan cilexetil)-based regimen and a β-blocker (atenolol)–based regimen for 52 weeks on common carotid artery (CCA) and left ventricular structure in hypertensive patients in a randomized, double-blind study. Clinic brachial BP and 24-hour ambulatory BP, carotid BP, left ventricular mass index, CCA intima-media thickness, lumen diameter, intima-media area, and carotid blood flow were measured. Distensibility, circumferential tensile stress, Young’s elastic modulus (Em), and shear stress (&tgr;) in the CCA were also calculated. Results— Both candesartan and atenolol reduced intima-media thickness and intima-media area and increased distensibility to similar extents after 52 weeks of treatment. Despite similar reductions in BP, treatment with atenolol resulted in a lesser reduction in left ventricular mass index, a decrease in lumen diameter, and a reduction in carotid blood flow compared with candesartan. Conclusions— BP-independent effects of ARB on cardiac and arterial structure may contribute to the beneficial effects of these agents on cardiovascular disease.

Wave intensity analysis: a novel non-invasive method for determining arterial wave transmission

Wave intensity analysis is a novel technique for assessing wavelet transmission in the cardiovascular system. Using this tool, we have developed non-invasive techniques to study wave transmission in both central & peripheral arteries in man. The aim of this study was to determine the reproducibility of various haemodynamic measures in the carotid, brachial and radial arteries. 12 treated hypertensive men underwent applanation tonometry and pulsed Doppler ultrasound studies of the carotid, brachial and radial arteries on 2 occasions. Coefficients of variation for the local wave speed, cardiac compression wave intensity and main reflected wave intensity ranged between 3.7-6.6%, 8.2-11.4% and 12.5-19.6% respectively. We conclude that non-invasive methods used for wave intensity analysis are reproducible & provide additional information regarding the complex phenomenon of arterial wave transmission in man.

Central Aortic Pressure Influences Pulse Wave Velocity

To the Editor: The study reported by Lantelme and colleagues1 suggests that increasing heart rate is independently associated with higher aortic pulse wave velocity (PWV). We are concerned that the authors of this study have neither addressed the impact of central aortic pressure changes on PWV nor the presence of potential bias in their study. In Lantelme’s study, PWV represented the average wave speed from the carotid artery, through the aorta, and down to the common femoral artery. Local wave speed varies between different arteries and along the length of the aorta,2 and, furthermore, may alter in response to changes in local pressure.3 Knowledge of central aortic pressure is therefore an essential requirement for the interpretation of studies using PWV. Central aortic pressure is influenced by left ventricular ejection and the phenomenon of wave reflection.3 Systolic pressure in peripheral muscular arteries tends to be higher than in those measured centrally,4 particularly in younger subjects, and amplification of the central pressure pulse toward the periphery may be influenced by a number of factors, including heart rate.5–7 Previous work using similarly aged subjects5,6 suggested that, over a similar range of heart-pacing rates, there was a significant increase in …