Association between flicker‐induced vasodilatation and flow mediated vasodilatation in patients with diabetes, systemic hypertension and hypercholesterolemia

Abstract

Abstract Purpose Flicker induced vasodilatation is reduced in patients with vascular related diseases. However, the reason for this diminished response is unclear, but may be related to endothelial dysfunction. Currently, the standard method to assess endothelial function in vivo is flow mediated vasodilatation (FMD). Thus, the present study was performed to investigate whether a correlation exists between flicker induced vasodilatation and FMD in patients with diabetes and patients with mild systemic hypertension and/or hypercholesteremia. Methods In the present study 20 patients with insulin dependent diabetes, 40 patients with systemic hypertension (systolic blood pressure:140‐159 mmHg; diastolic blood pressure 90‐99 mmHg) and/or serum cholesterol plasma levels > 250 mg/dl and 20 healthy control subjects were included. The flicker response was measured using the Dynamic Retinal Vessel Analyzer. FMD was determined using a high resolution ultrasound system, measuring brachial artery diameter reactivity during reperfusion after arterial occlusion. Results The flicker response of both retinal arteries and veins was significantly reduced in the two patients groups. Likewise, FMD was significantly reduced in patients as compared to healthy controls. However, only a weak correlation between flicker induced vasodilatation and FMD was observed. Conclusion The study confirms evidence that flicker responses and FMD is reduced in the selected patients groups. Whether the weak correlation between FMD and flicker is due to the different stimulation type, the different vascular beds measured or other mechanisms has yet to be investigated.