Impact of acute hyperglycaemia on endothelial function and retinal vascular reactivity in patients with Type 2 diabetes

P>Aim In diabetes, endothelial dysfunction and an altered retinal blood flow have been reported and precede overt macrovascular and microvascular disease. Furthermore, an association between postprandial hyperglycaemia, retinopathy and cardiovascular disease has been observed. Methods Endothelial function and retinal vascular reactivity have been measured in baseline conditions in 10 healthy control subjects and 21 patients with Type 2 diabetes. In the patients with Type 2 diabetes, endothelial function and retinal vascular reactivity have been also measured every hour, for 4 h, during an oral glucose tolerance test. Endothelial function has been evaluated by measuring flow-mediated vasodilation of the brachial artery, while retinal vascular reactivity has been measured using a retinal vessel analyser, during a flicker. Results At 1 and 2 h after glucose ingestion, endothelial function decreased (P < 0.05), while retinal vascular reactivity increased, even at 3 h (P < 0.05), vs. the baseline values. Conclusion Our data highlight that acute hyperglycaemia impacts on endothelial function simultaneously at both macrovascular and at microvascular levels, inducing functional change, which could contribute towards explaining the clinical evidence of a strong association between postprandial hyperglycaemia, cardiovascular disease and retinopathy.