As an in vivo measure of endothelial dysfunction we quantified circulating levels of P-selectin, an established marker of endothelial dysfunction.[29] P-selectin was moderately elevated in diabetic patients (11% increase compared to non-diabetic patients, P = 0.14; 15% increase, P = 0.04 after excluding a single non-diabetic subject with extremely high P-selectin levels). This evidence concerns the gene SELP and endothelial dysfunction.