Elevated serum levels of soluble vascular cell adhesion molecule-1 in NIDDM patients with proliferative diabetic retinopathy

Abstract

We studied 68 Japanese NIDDM patients (38 men and 30 women), aged 56.9±1.2 years (range 33–75 years), with a BMI of 23.1±0.5 kg/m 2 without hypertension, dyslipidemia, and diabetic macroangiopathy for evaluating the relationship between serum soluble vascular cell adhesion molecule-1 (sVCAM-1) levels and the severity of diabetic retinopathy. Fundus examination was performed by an ophthalmologist using an ophthalmoscope, and the findings were graded as: (1) no signs of diabetic retinopathy (NDR), (2) background diabetic retinopathy (BDR), or (3) proliferative diabetic retinopathy (PDR). Serum sVCAM-1 levels were measured in duplicate by enzyme-linked immunosorbent assay using the soluble VCAM-1 KIT (R&D Systems Ltd., Ablingdon, Oxfordshire, UK). There was no difference in serum sVCAM-1 levels between patients with BDR ( n=17) and patients with NDR ( n=40) (1035.3±104.4 and 978.8±48.9 ng/ml, respectively, P=0.8), but patients with PDR ( n=11) showed a significant increase of serum sVCAM-1 levels compared with patients with NDR (1281.8±166.3 and 978.8±48.9 ng/ml, respectively, P=0.02). Although serum sVCAM-1 levels were correlated, not only with age but also with the known diabetic duration ( r=0.39, P=0.001, and r=0.40, P=0.0007, respectively), age-adjusted sVCAM-1 levels were still significantly higher in the PDR group than in the NDR group. In contrast, serum sVCAM-1 levels were not related to the presence of diabetic nephropathy or HbA 1c levels. Our results suggest that sVCAM-1 might be implicated in the development of the diabetic retinopathy, and measurement of serum sVCAM-1 levels in NIDDM patients may be clinically useful for assessing the severity and possibly the activity of diabetic retinopathy.