HYPERFILTRATION IN AFRICAN-AMERICAN PATIENTS WITH TYPE-2 DIABETES - CROSS-SECTIONAL AND LONGITUDINAL DATA

OBJECTIVE - Hyperfiltration may play a role in the development of diab etic nephropathy African-American patients with diabetes have more tha n a fourfold increase in end-stage renal disease. The purpose of this study is to evaluate the impact of hyperfiltration on renal function i n African-American patients with type 2 diabetes. RESEARCH DESIGN AND METHODS - Renal function of 194 African-American patients with diagnos ed type 2 diabetes from 1 month to 36 years was assessed by studies of isotopic glomerular filtration rate (GFR), serum creatinine, creatini ne clearance, and 24-h urinary albumin excretion rates. Thirty-four pa tients with a duration of diagnosed type 2 diabetes from 1 month to 10 years were found to have hyperfiltration (GFR greater than or equal t o 140 ml . min(-1) . 1.73 m(-2)). Fifteen of these patients received l ongitudinal follow-up of renal function for as long as 15 years after the initial study. RESULTS - Hyperfiltration is present in 15 (36%) of 42 patients whose duration of diagnosed type 2 diabetes is <1 year, a nd it persists for up to 10 years in 14-20% of patients with diagnosed type 2 diabetes. Patients with hyperfiltration are younger than their counterparts without hyperfiltration when matched for duration of dia gnosed diabetes. When followed over time, those patients with hyperfil tration were not more likely to develop impaired renal function as mea sured by GFR or creatinine clearance. CONCLUSIONS - Hyperfiltration do es not identify patients at risk for deterioration in renal function.