Objective: Non-enzymatic glycosylation of proteins occurs in diabetes and advanced glycosylated end products can accumulate in long lived proteins such as vascular collagen and reduce the elasticity of vessel walls. To evaluate the potential association of advanced glycosylated end products in collagen with diminished arterial elasticity in diabetes, 14 diabetic and 14 age and sex matched non-diabetic patients with coronary artery disease were studied.
Methods: Arterial elasticity was assessed in terms of carotid to femoral pulse wave velocity and by measuring the change in ascending aortic diameter induced by pulse pressure. Collagen linked fluorescence, a measure of advanced glycosylated end products, was determined from tissue specimens of the skin, ascending aorta, and right atrial appendage taken during coronary bypass surgery.
Results: As a sign of diminished arterial elasticity, carotid to femoral pulse wave velocity was raised (p < 0.01) and change in ascending aortic diameter tended to be diminished (p = 0.09) in the diabetic patients. Collagen linked fluorescence was increased (p < 0.05) in the myocardium of the diabetic group, but the difference in skin and aorta was not significant. Collagen linked fluorescence between the aorta, skin, and myocardium correlated with each other (r = 0.64-0.77). Collagen linked fluorescence in the aorta and myocardium correlated with carotid to femoral pulse wave velocity (r = 0.63 and r = 0.67, respectively) in the diabetic group but not in the control group.
Conclusions: These data suggest that non-enzymatic glycosylation of matrix proteins, and specifically collagen, may modify arterial elasticity in diabetic patients with coronary artery disease.