Low molecular weight proteinuria in diabetic children--a marker of early diabetic nephropathy?

Twenty-four hour urine specimens of 67 diabetic children aged 1-17 years without any renal manifestations were examined by SDS-polyacrylamide gel electrophoresis (SDS-PAGE). The excretion of high molecular weight, i.e. glomerular proteins was compared to that of low molecular weight, i.e. tubular proteins corresponding to more or less than 68,000 daltons. The glomerulo-tubular protein ratio (GTPR) obtained was significantly lower in diabetic patients compared with 30 healthy children of the same age and showed a linear decrease with longer duration of diabetes.