Unsuspected diabetic glomerulosclerosis.

Six patients without overt diabetes mellitus underwent renal biopsy for suspected glomerulonephritis. All were demonstrated to have diabetic glomerulosclerosis and subsequently were found to have abnormal glucose tolerance tests. Electron microscopy was critical in making the correct diagnosis in five of six patients. The reported cases represent 3% of a series of 200 patients who had a renal biopsy to evaluate possible glomerulonephritis. Renal manifestations of diabetes mellitus may antedate glycosuria and other more common presenting symptoms of this disease.