Changes of glomerular filtration rate in early diabetes

The GFR was measured by ^99mTc-DTPA in 16 cases of IDDM and 7 cases of NIDDM without microvascular complications and 17 normal controls.The results showed that the GFR in patients with IDDM was（148.6±29.1ml/min/1.73m²）23.3% higher than that in the controls,120.5±16.8ml/min/1.73m².When the GFR of male and female diabetics compared separately,it was found to be higher in IDDM group than in normals.No relationship between GFR in IDDM and course of diabetes,levels of blood sugar or glycosylated haemoglobin A was found.The GFR of patients with NIDDM was 109.7±16.4ml/min/1.73m²,not significantly different from that of normal.It was suggested that increased GFR was one of the abnormal characteristics of renal functional change in early IDDM.The mechanism of elevated GFR and its possible effect on the development of diabetic nephropathy were discussed.