Retinol binding protein: a short half life determinant of protein non enzymatic glycation in diabetes

The non enzymatic glycation of circulating and structural proteins is the main biochemical consequence of the chronic hyperglycaemia of diabetes mellitus. Retinol binding protein (RPB) is a 21K plasma globulin with an half life of 12 hr; its non enzymatic glycation may reflect the variation of short term metabolic control (1-4 days). In this study two blood samples were withdrawn at four days interval from 24 non insulin dependent diabetic patients. Glycated RBP was measured by a two-site immunoradiometric assay and its variations correlated with the correspondent changes in the blood glucose level. A significant correlation (r = 0.471; p less than 0.02) was found between the time 4/time 0 ratios of glycated RBP and the time 4/time 0 ratios of blood glucose. These data suggest that measurement of non-enzymatically glycated RBP may be a useful tool to evaluate the short term state of non enzymatic glycation in diabetes.