6.4 large and small artery crosstalk in patients with type 2 diabetes

Background: Vascular complications to diabetes mellitus have, traditionally, been divided in to micro- and macroangiopathy. However, a growing body of evidence has put this categorical division into question, as large artery stiffness has been associated with microvascular complications in diabetics, e.g. diabetic retinopathy. The pathophysiology behind this association is poorly understood. The retinal arterioles lack sympathetic innervation and blood supply is autoregulated to accommodate changes in blood pressure and metabolic demand. Recently, dynamic vessel analysis of the retina, has made direct observation of the dynamic function of the microvascular bed of the retina feasible (spontaneous vessel oscillations). However, the crosstalk between dynamic retinal arteriole functioning and large artery stiffness remains to be elucidated. Methods: We will include 20 type 2 diabetics and 20 sex- and age-matched controls. Arterial stiffness (carotid-femoral Pulse Wave Velocity) is assessed using applanation tonometry (SphygmoCor). Retinal blood supply regulation is examined using the Dynamic Vessel Analyzer under two conditions: i) during exposure to flickering lights which increases the metabolism of the retina, and ii) during static exercise (hand-weight lifting) which elevates systemic blood pressure. Results: Results will be ready for presentation at the congress. Currently, 7 participants have been examined and 16 more participants have been recruited. Study completion September 2016. Perspectives: This study provides new insight into large-small artery crosstalk. We hypothesize that large artery stiffness is associated with reduced spontaneous vessel oscillations and perturbed retinal blood flow regulation.