Glucose titration studies in patients with chronic progressive renal disease.

Glucose titration studies were performed on 17 patients with either chronic pyelonephritis or chronic glomerulonephritis. Glomerular filtration rates for the group ranged from 4.3 to 58.1 ml per minute. In none of the patients in whom the glomerular filtration rate was over 15 ml per minute was there appreciable splay, and the mean titration curve for these patients resembled that obtained by Smith and associates in normal man (1). In half of this group of eight patients, GFR ranged from 16.6 to 22.7 ml per minute; in the other half values ranged from 42.3 to 58.1 ml per minute. Yet, the mean titration curves were identical for the two groups. In addition, no difference was observed in the titration curves for patients with pyelonephritis and those with glomerulonephritis. In patients with GFR values below 15 ml per minute, increased splay was observed, and below a GFR of 10 ml per minute, the splay was very marked. Both the absence of exaggerated splay in patients with reduction of glomerular filtration rate by as much as 85%, and the emergence of exaggerated splay in patients with more marked reduction of GFR, require explanation. Theoretical considerations are presented in the text.