Diabetic nephropathy in adolescence: appearance during improved glycemic control

Two girls, aged 15 and 14 years, with poorly controlled insulin-dependent diabetes (IDD) of 9 and 7 years duration, respectively, developed overt and persistent proteinuria shortly after rapid increases in insulin therapy and improved glycemic control. Renal biopsies showed diffuse diabetic glomerulosclerosis. Both patients maintained normal or increased creatinine clearances. Direct ophthalmoscopy and fluorescein retinal angiography demonstrated nonproliferative diabetic retinopathy in the first patient, which deteriorated after 6 weeks of strict metabolic control; the second patient had normal retinas. The appearance of clinical proteinuria during this brief period of good glycemic control suggests that the latter may have unmasked a preexisting condition. Possible pathophysiologic mechanisms initiating the proteinuria in these patients are reviewed.