An evaluation of renal biopsy in type-II diabetic patients

Objective: To determine the renal damage in type-II diabetic patients, who underwent renal biopsy for impaired renal functions and its role in overall patient management. Study Design: Descriptive, cross-sectional study. Place and Duration of Study: The Kidney Postgraduate Centre, Karachi, Pakistan from January 2000 to May 2005. Methodology: Histopathological evaluation of 73 patients of type-II Diabetes mellitus were included who underwent renal biopsy. Renal biopsy was performed when a renal disease other than diabetic nephropathy was suspected because of the presence of haematuria, nephrotic syndrome, non-nephrotic proteinuria < 3 gms/day in the absence of retinopathy, rapidly progressive glomerulonephritis and renal insufficiency of unknown origin. On the basis of light microscopy and immunofluorescence, three groups of patients were defined. Group I was characterized by diabetic glomerulosclerosis (DGS) only, group II by the prevalence of vascular changes, while group III had sub-groups IIIa (DGS co-existing with non-diabetic renal diseases) and IIIb (non-diabetic renal diseases without DGS). Results: Among the 73 patients studied, 20 (27.3%) had diabetic glomerulosclerosis alone (group I), 17 (23.3%) showed occurrence of vascular changes (group II), and 36 (49.3%) had non-diabetic renal diseases (group III). Mean serum creatinine level was significantly greater in group II than in group I and III (p < 0.001). Amount of proteinuria and the presence of haematuria did not show a statistically significant difference in groups I, II and III. The systolic and diastolic blood pressure was higher in groups II as compared to group I and III (p < 0.001). The percentage of sclerotic glomeruli, tubular injury and interstitial inflammation in group II were significantly greater than group I and III (p < 0.001). Conclusion: Type-II diabetic patients undergoing renal biopsy for impaired renal functions constituted a heterogeneous group of renal damage. This study emphasized the usefulness of renal biopsy for determining the pattern of renal damage that would aid in the overall management of the patients.