Nondiabetic renal disease in type 2 diabetic patients: a review of our experience in 220 cases

Abstract

Background: The purpose of this retrospective study was to evaluate the renal biopsies performed on type 2 diabetic patients for suspicion of nondiabetic renal disease (NDRD) and to correlate the pathological finding with the clinical and laboratory findings.

Methods: From January 1999 to December 2009, 220 people with type 2 diabetes for clinically suspected NDRD underwent renal biopsy. The case records of these patients were retrospectively analyzed. Based on the biopsy findings, patients were divided into two groups: Group I, isolated diabetic glomerulosclerosis (DGS), and Group II, NDRD with underlying DGS. Clinical and laboratory data were analyzed in relation to the histopathological findings.

Results: Of the 220 patients studied, 153 were males and 67 were females. The average age was 51.35 years (30-79). Renal biopsy showed that 100 patients (45.5%) had NDRD with underlying DGS. Group II had a significantly higher level of proteinuria and hematuria but less frequent diabetic retinopathy. There was no significant difference between the two groups in age, duration of diabetes, presence of hypertension, serum creatinine, and glomerular filtration rate. IgA nephropathy was the most common, accounting for 34% of Group II, membranous nephropathy ranked second accounting for 22.0%, followed by mesangial proliferative nephritis for 14%.

Conclusion: This study showed that IgA nephropathy is the commonest NDRD among diabetics. The absence of retinopathy, especially when associated with nephritic proteinuria and hematuria, strongly predicts NDRD superimposed on DGS. Renal biopsy should be performed in diabetics when the clinical scenario is atypical.