Progression of Proteinuria in Type 1 and Type 2 Diabetes

Abstract

A longitudinal study evaluating the time course of the transition from normal to micro‐albuminuria, and then on to macroalbuminuria, was made over a mean period of 7 years in a cohort of 52 patients with Type 1 diabetes and 61 patients with Type 2 diabetes. Transient episodes of micro‐ and macroalbuminuria were often observed before the ultimate development of persistent Albustix‐positive proteinuria. The transition from normal to micro‐albuminuria and from micro‐ to macroalbuminuria was characterized by rises in renal albumin clearance accompanied by lesser rises in total proteinuria. Seven patients with Type 1 and 12 with Type 2 diabetes showed evidence of progression, the interval for the transition from normal to macroalbuminuria varying from 3 to 5 years. In Type 1 diabetic patients, the development of micro‐ and macroalbuminuria was associated with a decline in renal function and a rise in systolic blood pressure without a significant change in blood glucose control. In Type 2 diabetic patients, the development of microalbuminuria was associated with a small decline in renal function but no change in blood pressure or blood glucose control. It is concluded that the transition from normal to micro‐ and on to macroalbuminuria may be more rapid then previously reported and varies considerably among individuals.