Frequency of Non-Diabetic Renal Disease (NDRD) in Type II Diabetes Mellitus

Objective: To describe the frequency of NDRD in type II diabetic patients who underwent renal biopsy for deranged renal functions that includes haematuria, proteinuria in the nephrotic and non-nephrotic range and rapidly worsening renal failure. Methods: A descriptive study was undertaken in the Department of histopathology at The Kidney Postgraduate Center, Karachi, Pakistan from January 2000 to May 2005. The renal biopsies of 73 patients of type II diabetes were evaluated when a renal disease other than diabetic glomerulosclerosis (DGS) was suspected because of unexplained haematuria, clinically significant proteinuria in nephrotic and non-nephrotic range and rapidly progressive renal failure or unexplained renal failure with normal sized kidney. Three groups of patients were defined on the basis of renal damage noted on light microscopy and immunoflourescence investigations. Group I was NDRD alone, group II NDRD with co-existent DGS and group III DGS alone. The relationship of histology with clinical profile in each group and duration of diabetes were noted and analyzed using SPSS 15 software. Results: Of the 73 patients studied 46 were males and 27 were females (1.7: 1). Group I and II tended to have a younger age group at presentation (49.26 +/- 9.37 years and 49.0 +/- 5.72 years respectively) than group III (53.62 +/- 6.62 years). The mean duration of diabetes was 9.9 +/- 10.42 years in group I, 7.5 +/- 3.78 years in group II and 13.31 +/- 1.71 years in group III. Among patients 30(41.1%) had NDRD alone, 06(8.21%) had NDRD co-existent with DGS, and 37(50.7%) had DGS alone. Focal segmental glomerlosclerosis (FSGS) and tubulointerstitial nephritis (TIN) were the most common lesion and accounted for 22.2% and19.4% respectively. Amount of proteinuria was higher in patients of NDRD (3.064 +/- 1.38 gms/24hrs in group I and 3.316 +/- 0.97gms/24hrs in group II) than those of DGS (2.815 +/- 0.916 gms/24hrs) but it did not reach statistical significance. Serum creatinine was significantly raised in patients of group III (3.391 +/- 0.927 mg/dl) versus group I (2.563 +/- 0.95 mg/dl) and II(2.633 +/- 0.952mg/dl) (p 0.002). The presence of haematuria was seen in greater number in patients of NDRD (32.5% in group I and 33.3% in group II) versus DGS (in group III 29.6%), but it did not reach statistically significant values. Conclusion: This study shows a high frequency of NDRD in type II diabetic patients who underwent a renal biopsy for impaired renal functions emphasizing the significance of biopsy in such patients in order to tailor their management accordingly.