Agarose gel electrophoresis with nitroblue tetrazolium coloration for determination of glycated lipoproteins in serum from diabetics.

We describe a simple method for determining glycated lipoproteins (glc LPs) in serum by agarose gel film electrophoresis, with color development with nitroblue tetrazolium. The resulting blue bands on the film were measured densitometrically at 545 nm to quantify alpha-, pre beta-, and beta-glc LPs. Each glc LP concentration (mmol/L) was calculated from the resulting percentage multiplied by the value for serum fructosamine. Only glc beta-LP was significantly correlated with the atherogenic index: low-density LP-cholesterol/high-density LP-cholesterol (r = 0.545, P less than 0.01). The concentration of glc beta-LP in sera from diabetics was 2.2-fold higher (0.84 mmol/L) than that (0.38 mmol/L) in normal individuals. Diabetic patients with complications had higher concentrations of glc beta-LP, with large individual variations, than did patients without complications, the greatest concentration (1.02 mmol/L) being found in patients with diabetic retinopathy and (or) nephropathy. The concentration of glc beta-LP (glc LDL) in serum seems to depend on the extent and duration of hyperglycemia; it may also be a useful diagnostic indicator of diabetic atherogenesis, microangiopathy (e.g., retinopathy or nephropathy), and other complications.