Early onset of clinical diabetic nephropathy in children--a new subgroup?

The onset of fixed proteinuria and hypertension in insulin-dependent diabetic is generally associated with eventual renal insufficiency due to diabetic nephropathy or with a superimposed glomerulopathy. We report three adolescents with normal renal function who developed fixed proteinuria and hypertension after only 7 to 11 years of insulin-dependent diabetes mellitus. Blood pressure ranged from 130/95 to 165/104 mmHg, urinary protein excretion was 1.31 to 1.37 g/24 hours, and creatinine clearance ranged from 98-133 ml/min/1.73 m2. Renal biopsy revealed changes consistent only with diabetic glomerulosclerosis. Follow-up evaluation for 11 months to 3 1/2 years revealed blood pressure reductions to 125/78-140/85 mmHg as a result of antihypertensive medications. Creatinine clearance increased by 12-20% and urinary protein excretion remained unchanged. We conclude that these patients may represent an unusual subgroup of insulin-dependent diabetics with early development of clinical and pathological diabetic nephropathy in the face of normal renal function.