title: Glomerular structure in type-1 (insulin-dependent) diabetic patients with normo- and microalbuminuria.
abstract: Kidney biopsies from 15 type-1 (insulin-dependent) diabetic patients with a range of albumin excretion (AER) were analyzed. Nine patients had normal AER, and six had microalbuminuria. Basement membrane thickness, BMT, and mesangial matrix volume fraction, Vv(mat/glom), were obtained from at least three glomeruli per biopsy. Mesangial structures were estimated with electron microscopic analysis at three levels in each glomerulus. Glomerulopathy parameters were significantly increased in micro- versus normoalbuminuric patients with the following means and (CV): BMT 571 nm (0.12) and 442 nm (0.25), P = 0.03; Vv(mes/glom) 0.31 (0.20) and 0.22 (0.14), P = 0.002; Vv(matrix/glom) 0.17 (0.25) and 0.11 (0.28), P = 0.006; matrix star volume 56 microns 3 (0.47) and 22 microns 3 (0.43), P = 0.02. A positive correlation obtained between AER and each of the glomerulopathy parameters, BM thickness, Vv(mes/glom) and Vv(matrix/glom), as well as between AER and a structural index expressing the sum of changes in the peripheral BM and in the mesangium (r = 0.62, P = 0.01). The results indicated a parallel course of mesangial and peripheral BM changes: a positive correlation obtained between BM thickness and mesangial parameters [BMT versus Vv(matrix/glom): r = 0.82, P = 0.0001] and the ratio of the two subsets of glomerular BM material (PBM:matrix) did not show significant difference between normo- and microalbuminuric groups. The data give strong support to the contention that the transition from normo- into the microalbuminuric phase is linked to progressing glomerulopathy.
authors.affiliation: Unit for Metabolic Medicine, UMDS, Guy's Hospital, London, England.
authors.forename: J D
authors.initials: JD
authors.lastname: Walker
authors.forename: C F
authors.initials: CF
authors.lastname: Close
authors.forename: S L
authors.initials: SL
authors.lastname: Jones
authors.forename: M
authors.initials: M
authors.lastname: Rafftery
authors.forename: H
authors.initials: H
authors.lastname: Keen
authors.forename: G
authors.initials: G
authors.lastname: Viberti
authors.forename: R
authors.initials: R
authors.lastname: Osterby
mesh_terms: D000419:Albuminuria / Q000209:etiology*; D001485:Basement Membrane / Q000648:ultrastructure; D001706:Biopsy; D003922:Diabetes Mellitus, Type 1 / Q000150:complications / Q000473:pathology*; D006801:Humans; D007678:Kidney Glomerulus / Q000473:pathology*; D012016:Reference Values