Abstract 18117: Increased Vascularization In Shoulder Regions Of Carotid Plaques Taken From Patients With Diabetes Mellitus
Introduction: Increased vascularization is considered an important contributing factor for plaque vulnerability. Patients with diabetes suffer from microvascular proliferative disease resulting in renal damage and visual loss, and an increased vascularization has been shown in femoral atherosclerosis specimens.
Hypothesis: We assessed the hypothesis that patients with diabetes have increased vascularization of carotid atherosclerotic plaques, especially in the critical shoulder regions of the plaque.
Methods: Carotid thrombendarterectomy specimens, clinical data and blood samples were collected from consecutive patients with either pharmacological treatment for diabetes (n=26) or with normal glucose tolerance (NGT, n=85) having a symptomatic carotid artery stenosis (median 85 days after clinical event). After thrombendarterectomy, plaques were fixed in formalin and transverse tissue sections prepared from the most proximal part of the internal carotid artery. Histopathology and immunohistochemistry were performed for detection of endothelial cells (CD34), macrophages (CD68), smooth muscle cells, vascular endothelial growth factor (VEGF) and its receptor (VEGF-R2).
Results: A significantly higher CD34+ vessel density was found in the shoulder region of plaques taken from patients with diabetes compared with NGT (P<0.05). Surprisingly, in the same area CD68 staining were lower in patients with diabetes (P<0.01). VEGF-R2 but not VEGF expression was increased (P<0.05) in shoulder region of plaques from patients with diabetes. When the full transverse tissue section were analyzed no difference in number of CD34+ vessels were detected. No differences were detected between patients with diabetes and NGT as regards; s-hsCRP, cholesterol fractions, s-VEGF, time since last clinical event, smoking or statin treatment.
Conclusions: A higher vessel density was found in the critical shoulder region of the plaque, supporting our hypothesis. Surprisingly, this increase was not accompanied by a higher macrophage density but possibly explained by increased VEGF-R2 expression. The increased plaque vascularization may help explain why patients with diabetes are at increased risk of atherosclerotic complications.
- © 2010 by American Heart Association, Inc.