The Natural History of Diabetic Renal Disease

Thirty-one diabetics, on whom renal biopsies had been performed approximately 11 years previously, were reviewed in order to determine the natural history of diabetic renal disease over a long period. At the time of biopsy it was shown that neither renal function nor proteinuria was closely related to the histological changes. Although all those with heavy proteinuria had advanced renal changes, some patients with serious biopsy lesions had no proteinuria. The worst prognosis was demonstrated among those patients with marked (Grade II and Grade III) renal changes when this was associated with heavy proteinuria (more than 3 g per 24 hours): all such patients died during the follow-up period, usually from renal failure. When proteinuria was smaller in amount the prognosis was variable, regardless of the histological changes, and renal function sometimes remained unaltered for many years. The factors responsible for the onset of rapid deterioration of renal function are not known. Hypertension was a late feature and was not usually demonstrated until the renal failure was quite advanced. Both the age of the patients and the duration of the diabetes seemed unrelated to the prognosis. Impairment of vision due to advanced diabetic retinopathy was a fairly constant accompaniment of chronic renal failure, and together with coronary artery disease, makes the value of chronic dialysis and transplantation in such patients rather uncertain.