Clinical Predictors of Non-diabetic Renal Disease and Role of Renal Biopsy in Diabetic Patients with Renal Involvement: A Single Centre Review

Background: Type 2 diabetes mellitus (T2DM) is reportedly the leading cause of end-stage renal disease (ESRD) worldwide. However, non-diabetic renal diseases (NDRD) are not uncommon among T2DM patients with renal involvement. Our study aimed to examine the prevalence of NDRD in T2DM and clinical markers for diabetic nephropathy (DN) and NDRD and to determine the role of renal biopsy in T2DM patients and its impact on clinical practice. Methods: We conducted a retrospective analysis of T2DM patients in whom renal biopsies were performed from January 2004 to March 2008 (n = 110). Results: Biopsy results were divided into three groups: group I/pure DN (62.7%), group II/isolated NDRD (18.2%), and group III/mixed lesions (19.1%). The causes of NDRD in decreasing order of frequency were acute interstitial nephritis, glomerulonephritides, hypertensive renal disease, and acute tubular necrosis. Significant clinical markers for DN are presence of diabetic retinopathy and longer duration of diabetes. For NDRD, useful clinical markers include the presence of acute renal failure and microscopic hematuria. In the DN subgroup, Indians had significantly shorter duration of diabetes on biopsy compared with Malays and Chinese. Conclusions: NDRD is prevalent in T2DM patients, and given its potentially treatable nature, renal biopsy should be considered in T2DM patients with nephropathy, especially in those with atypical features.