Abstract
Glomerular filtration rate and renal plasma flow were examined in 16 young male non-proteinuric diabetics (mean age 28·4 years) with a duration of diabetes of over 15 years (mean duration 21·5 years.) In this selected group of long-term diabetics the glomerular filtration rate was clearly increased, the mean being 136 ml/min (±S.D. 11·8) (normal value 114 ml/min (±14·1), being comparable to that found earlier in short-term diabetics. There was no change in renal plasma flow. It is concluded that kidney function is generally well preserved in long-term diabetics who have not developed proteinuria.