Plasma matrix metalloproteinases, low density lipoprotein oxidisability and soluble adhesion molecules after a glucose load in Type 2 diabetes

BACKGROUND: Acute hyperglycaemia is an independent cardiovascular risk factor in Type 2 diabetes which may be mediated through increased oxidative damage to plasma low density lipoprotein, and in vitro, high glucose concentrations promote proatherogenic adhesion molecule expression and matrix metalloproteinase expression. METHODS: We examined these atherogenic risk markers in 21 subjects with Type 2 diabetes and 20 controls during an oral 75 g glucose tolerance test. Plasma soluble adhesion molecule concentrations E-selectin, VCAM-1 and ICAM-1, plasma matrix metalloproteinases MMP-3 and 9 and plasma LDL oxidisability were measured at 30 minute intervals. RESULTS: In the diabetes group, the concentrations of all plasma soluble adhesion molecules fell promptly all p < 0.0001 related principally to glycaemic excursions, but such changes also occurred in the control group. Plasma MMP-3 and -9 concentrations were lower p < 0.05, and LDL oxidisability greater p < 0.01 in the diabetes group but did not change in either group. There was a direct relationship between plasma MMP-9 and s ICAM-1 in the controls r = 0.62; p = 0.006 perhaps suggesting a functional relationship between s ICAM-1 shedding and MMP-9. CONCLUSIONS: A glucose load leads to a rapid fall in plasma soluble adhesion molecule concentrations in Type 2 diabetes and controls, perhaps reflecting reduced generation of soluble from membrane forms during enhanced leukocyte-endothelial adhesion or increased hepatic clearance, without changes in plasma matrix metalloproteinase concentrations or low density lipoprotein oxidisability. These in vivo findings are in contrast with in vitro data.