Renal changes in long-term type 1 (insulin-dependent) diabetic patients with and without clinical nephropathy: a light microscopic, morphometric study of autopsy material.

The relationship between clinical diabetic nephropathy and morphological renal changes was studied in autopsy material from 34 long-term Type 1 (insulin-dependent) diabetic patients of juvenile onset. Seventeen had no clinical signs of nephropathy (defined by persistent proteinuria, hypertension, and elevated serum creatinine) while a further 17 age-matched diabetic patients with a similar duration of diabetes had severe clinical nephropathy. The renal tissue was examined by morphometric light microscopy, using a point counting technique and the results compared with renal tissue from subjects who died without diabetes. In the diabetic patients without clinical nephropathy, arteriolohyalinosis was much more pronounced compared with non-diabetic subjects (2p less than 0.001) and within the glomeruli the amount of subcapsular fibrosis and glomerular mesangium was increased (2p less than 0.05 and less than 0.001, respectively). The area of open capillaries was decreased compared with non-diabetic subjects (2p less than 0.025), and the percentage of occluded glomeruli was significantly increased (2p less than 0.05). The diabetic patients with clinical nephropathy had significantly more interstitial tissue and glomerular mesangium (2p less than 0.001) and less open glomerular capillaries (2p less than 0.001) than diabetic subjects without clinical nephropathy, but severe glomerulosclerosis could be seen in the diabetic patients without any sign of clinical nephropathy. Serum creatinine correlated with the mesangial area (r = 0.792, 2 a less than 0.001). No difference was observed between the two diabetic groups regarding the degree of arteriolohyalinosis, the number of Kimmelstiel-Wilson lesions or exudative lesions.(ABSTRACT TRUNCATED AT 250 WORDS)