Correlation between carotid artery distensibility and serum vascular endothelial growth factor concentrations in type 1 diabetic subjects and nondiabetic subjects

The relationships between serum vascular endothelial growth factor (VEGF) c oncentrations and vessel wall ultrasonic characteristics in type 1 diabetic and nondiabetic subjects were assessed. Serum VEGF concentration was measu red, and ultrasound imaging and blood pressure recordings were performed in 41 type 1 diabetic subjects (hemoglobin A(1c) [HbA(1c)], 7.63 [1.17%]; dur ation of diabetes, 12 (0 to 23) years), and 50 nondiabetic subjects. Change in carotid artery luminal diameter during the cardiac cycle was measured u sing WI-mode ultrasound, from which percentage increase in carotid artery l uminal diameter was calculated; the carotid artery distensibility index was calculated as the ratio of percentage increase in carotid artery luminal d iameter and pulse pressure. Serum VEGF concentration was higher in the diab etic subjects (217 [135 to 336] v 137 [80 to 237] pg/mL; P = .009). The per centage increase in carotid luminal diameter during the cardiac cycle was n ot significantly different between the 2 groups (12.9 [10.2 to 15.7] v 13.0 [10.6 to 15.0%]; P = .270) despite significantly greater pulse pressure in the type 1 diabetic group (55 [45 to 71] v 46 [41 to 51] mm Hg; P = .0003) . The distensibility index was therefore lower in the diabetic subjects (0. 24 [0.10] v 0.28 [0.08%]/mm Hg; P = .031), There was a significant negative correlation between serum VEGF concentrations and mean percentage increase in carotid luminal diameter during the cardiac cycle in the diabetic group (r = -.36, P = .021) and in the nondiabetic group (r = -.28, P = .047). Th is negative correlation could be strengthened by relating mean percentage i ncrease in luminal diameter to pulse pressure to give the distensibility in dex. Therefore, serum VEGF concentrations correlated strongly and inversely with the distensibility index in the diabetic group (r = -.49, P = .001), in the nondiabetic group (r = -.29, P = .041), and in both groups analyzed together (r = -.42, P < .0001), Vessel wall distensibility may be an import ant determinant of serum VEGF concentrations in both diabetic and nondiabet ic populations and may underlie the previously observed association between blood pressure and serum VEGF concentrations. The pathophysiologic relevan ce of these findings remains to be elucidated. Copyright (C) 2001 by W.B. S aunders Company.