BACKGROUND
Glomerular hyperfiltration (GHF) is found in 30-40% of patients with type 1 diabetes at the onset of the disease. Several lines of evidence suggest that this might be responsible for the development of diabetic nephropathy. However, it is still controversial whether GHF is a risk factor in patients with type 2 diabetes. This led us to perform a five-year-prospective study in normoalbuminuric type 2 diabetic patients. METHODS: A total of 68 patients with type 2 diabetes were studied prospectively, They were all normoalbuminuric initially. Glomerular filtration rate was determined by the 51Cr-EDTA single injection method and urinary albumin excretion rate by the radioimtnunoassay method. RESULTS: GHF was present in 19 out of 68 patients. At follow-up, l7 out of 49 patients of the normofiltration group and 3 out of 19 patients of GHF group progressed to microalbuminuria (p>0.05). Multiple logistic regression analysis revealed that the known duration of diabetes, systolic hypertension, and the presence of retinopathy were independently associated with the development of microalbuminuria. CONCLUSION: Our study suggests that GHF does not predict the subsequent development of diabetic nephropathy as indicated by the elevation of the urinary albumin excretion rate during the five year interval.