THE ACUTE EFFECT OF HYPERGLYCEMIA ON VESSEL WALL PROPERTIES

Arterial distensibility is a marker of functional and structural vesse l wall properties. A decreased distensibility is an important risk fac tor for cardiovascular disease. In insulin-dependent diabetes mellitus of short duration, arterial stiffness has been reported to be increas ed, decreased or the same as in healthy control subjects. The influenc e of acute hyperglycaemia on arterial stiffness is unclear and might b e one of the factors responsible for the divergent results which have been observed. We investigated arterial distensibility locally in the carotid artery during hyper-and normoglycaemia using a glucose clamp t echnique. Eleven healthy normotensive men underwent both a hyperglycae mic and a euglycaemic clamp on separate days. Before and after 2h of c lamping, arterial diameter (D) and change in arterial diameter during the heart cycle (do) were measured with a non-invasive vessel wall mov ement detector system. Blood pressure (BP), pulse pressure (dP) and he art rate (HR) were recorded with a semi-automated device. Distensibili ty coefficients (DC), reflecting the intrinsic vascular wall elasticit y, and compliance coefficients (CC), reflecting the buffering capacity of the vessel, were calculated from D, do and dP. (DC=2dD/D*dP, CC=p idD*D/2*dP). There were no significant differences between the hyperg lycaemic and the euglycaemic clamp for D, DC and CC. These results sug gest that an acute systemic hyperglycaemia is not responsible for chan ges in diameter, distensibility and compliance of the carotid artery.