Diabetic Retinopathy Status as a Marker for More Severe Reduction in Circulating Endothelial Progenitor Cells and Systemic Atherosclerosis in Diabetics

Abstract

Diabetes is associated with a reduction and dysfunction of circulating endothelial progenitor cells (EPC), which hastens the onset and progression of systemic atherosclerosis. We hypothesize that diabetic retinopathy status may serve as a marker for more severe depletion of circulating EPCs and thus systemic atherosclerosis. We examined coronary calcifications, carotid intimal medial thickness and arterial segment pulse-wave velocities and their relationships with different subtypes of circulating EPC in 163 patients with type II diabetes (126 patients without retinopathy and 34 patients with retinopathy). Four subpopulations of EPC were determined by flow cytometry: CD34+, CD34/KDR+, CD133+, and CD133/KDR+ EPC, respectively. Patients with diabetic retinopathy had significantly lower CD34/KDR+ (1.42% vs 1.70%) and CD34+ EPC counts (5.49% vs 6.55%) than those without. The mean Agatston score for coronary calcification was significantly higher in those with diabetic retinopathy compared to those without diabetic retinopathy (248.38 vs 143.57, p =0.02). Furthermore, subjects with diabetic retinopathy had significantly higher carotid intimal medial thickness (0.91 mm vs 0.88 mm), heart-femoral PWV (976.68 vs 873.29) , heart-ankle PWV (1084 vs 1080) and brachial-ankle PWV (1815 vs 1782) those without. Our results demonstrated that the presence of diabetic retinopathy was associated with lower levels of circulating CD34+ and CD34/KDR+ EPCs, more severe carotid and coronary atherosclerosis as well as increased central and peripheral arterial stiffness.