Background: The clinical consequences of the results obtained by kidney biopsy in patients with diabetes mellitus Type 1 or Type 2 have been controversial. Our study was conducted to assess clinical symptoms and histological diagnoses in patients with diabetes mellitus Type 1 and Type 2 undergoing kidney biopsy.
Design, setting and patients: Observational study. The study included data from 567 consecutive renal biopsies of patients with diabetes mellitus Type 1 or 2 and chronic kidney disease (CKD) examined by standard histopathological procedures. The main outcome measures were incidence of diabetic nephropathy (DN) and glomerulonephritis (GN), predictors for the presence of both DN or GN.
Results: Approximately 70% of patients with diabetes mellitus Type 1 or 2 and evidence for CKD had DN. Glomerular diseases present in approximately 30% of patients with diabetes were predominantly immune complex GN and secondary focal glomerulosclerosis, followed by IgA-GN, which was associated with microhematuria (p = 0.01) and hypertension (p = 0.04). Only a minority had membranous GN, which was associated with nephrotic syndrome (p = 0.004). Progressive CKD predicted the presence of GN in diabetes mellitus Type 2 (r = -0.98; p = 0.02).
Conclusion: GN is not uncommon in patients with diabetes and evidence for CKD. Kidney biopsy should therefore be considered in patients with diabetes and progressive CKD.