Renal function in black Americans with type II diabetes.

Renal function was studied in 72 black individuals with Type II (noninsulin-dependent) diabetes mellitus. Glomerular filtration rate (GFR) was determined by the clearance of I125 iothalamate and renal plasma flow (RPF) by the clearance of I131 hippuran. Hyperfiltration as defined by a GFR of 140 ml/min/1.73m2 or greater was found in six of 18 individuals with new onset (1 year or less) diabetes mellitus. The number of individuals with hyperfiltration decreased as the duration of diabetes increased, and no individual with diabetes for greater than 10 years had hyperfiltration. Increasing duration of diabetes independent of age was also associated with an increase in the number of individuals with low glomerular filtration rates. The data indicate that Type II diabetes in black individuals causes hyperfiltration similar to that noted in Type I diabetes and decreasing renal function is a significant problem in Type II black diabetics.