Comparative evaluation of instrumental methods for studying the state of endothelium in type II diabetes mellitus

Introduction . The method for assessing the flow-dependent vasodilation (FDV) and vasodilation induced by local iontophoresis of acetylcholine (Ach) is widely used, but has not yet been introduced into everyday clinical practice. Aim . Comparison of 2 ultrasound methods for assessing endothelial function in patients with diabetes mellitus (DM). Materials and methods . Effectiveness of reactive hyperemia tests of the brachial artery was compared using Vivid7pro ultrasound device, GE, with transducer 7.5 MHz. and the endothelium-dependent vasodilation and Ach iontophoresis in the microvasculature of the forearm were evaluated using a Minimax-Doppler-K ultrasound device with a 25 MHz transducer. After iontophoresis Ach, the linear blood flow velocity (%) was measured in comparison with the initial velocity. FDV is expressed as a % increase in arterial diameter in response to the test performed. Results . % of increase in blood flow velocity in the DM group was less than that in the control group for 2–6 minutes after the test and varied from 105.35 to 119.11 % in the DM group and from 130.0 to 270.0 % in healthy control subjects (p<0.05 for 2–6 min). After occlusion of the artery in reactive hyperemia test, as well as after 20, 40, and 180 sec, patients with DM had a lower % of increase in the diameter of the vessel, compared with healthy control subjects. When performing Celermaer test in 7 patients (43.75 %), in a number of measurements, an increase in the diameter of the vessel of more than 10 % was observed (which is characteristic of healthy control subjects). Conclusion . We associated the poor reproducibility of reactive hyperemia of the brachial artery with the difficulty in interpreting the results, which is probably due to the real-time resolution of the ultrasound method, and the Doppler method for assessing the linear blood flow velocity in the microvasculature turned to be less operator-dependent and more reproducible.