Diabetes, Vol 36, Issue 5 612-619, Copyright © 1987 by American Diabetes Association
Advanced diabetic glomerulopathy. Quantitative structural characterization of nonoccluded glomeruli
R Osterby, HJ Gundersen, G Nyberg and M Aurell
Quantitative ultrastructural data were obtained from kidney biopsy material
of 12 long-term insulin-dependent diabetics. All patients had overt
diabetic nephropathy with increased urinary albumin excretion and reduced
glomerular filtration rate. Renal clearance of 51Cr-EDTA was in the range
of 16-50 ml X min-1 X 1.73 m-2. All patients received antihypertensive
treatment. A combined light- and electron-microscope study was performed. A
significant proportion of the glomeruli was totally occluded (mean 36%,
range 24-67%). Structural data presented relate only to the open,
still-functioning glomeruli. Comparison with data previously obtained
showed that the thickness of the peripheral basement membrane [647 nm,
coefficient of variation (C.V.) 0.22] was more than twice the normal value
(310 nm, C.V. 0.08); the width of epithelial foot processes (352 nm, C.V.
0.07) was significantly greater than in normal biopsies (224 nm, C.V.
0.06); and the mean volume of the open glomeruli was markedly increased
compared with normal and clearly exceeded that in the early diabetic
hypertrophy. Total mesangial volume and total basement membrane material
per open glomerulus were increased by 277 and 614%, respectively. However,
capillary length and surface per open glomerulus were similar to those
observed in early diabetic hypertrophy. These findings suggest that a late
glomerular hypertrophy with preservation of capillary surface occurs as a
compensatory phenomenon, prolonging renal survival for diabetic nephropathy
patients.