ABSTRACT
Glomerular hyperfiltration in Type 1 diabetes mellitus (DM) of short duration has been recognized for many years [1-3], with increments in renal plasma flow (RPF) and nephromegaly [3]. With the finding of early hyperfiltration, Stalder and Schmid proposed that these early functional changes may predispose the subsequent development of diabetic glomerulopathy [1]. Early support for the hypothesis that renal hyperperfusion and hyperfiltration contribute to diabetic glomerulopathy emanated from the finding of diabetic glomerulopathy only in the non-stenosed kidney in the setting of unilateral renal artery stenosis [4]. Similar studies have more recently been performed in the much larger patient population with Type 2 DM. Studies reveal a wide range of renal hemodynamics in this group, but provide clear evidence for elevations of glomerular filtration rate (GFR) and RPF in significant proportions of patients of Caucasian, Native-and African-American origin [5-12]. Furthermore, compelling evidence for the presence of renal hemodynamic abnormalities in Type 2 diabetes has been reported in Pima Indians [12]. In that study, transition from impaired glucose tolerance to Type 2 DM was accompanied by a 30% increase in GFR. An increase in GFR has been also reported in obesity [13], a condition which often accompanies Type 2 DM.
