Histopathological evaluation of kidney disease in patients with diabetes mellitus: Kidney biopsy findings in diabetes

Introduction: Non-diabetic kidney disease (NDKD), a treatable condition, is common in diabetic patients with atypical clinical presentations. Present study aimed to find out histopathological diagnosis of kidney disease in type 2 Diabetes mellitus (T2DM) with such presentations. Method: This was a hospital-based cross-sectional study conducted in the Nephrology department, Bir hospital, Nepal from Aug 2019 to January 2021. Total 29 diabetic patients with atypical presentations, the rapid rise of proteinuria alone (n=5), with microscopic hematuria (n=6), with impaired renal function (n=8), and the rapid rise of creatinine with (n=8) or without (n=2) microscopic hematuria were included. The baseline information was recorded and a kidney biopsy was performed. Result: The mean age of patients was 52.6±10.4 years and 75.9% were male. Diabetic retinopathy (DR) was absent in 82.8% of patients. NDKD was present alone in 20.7% and superimposed on diabetic kidney disease (DKD) in 34.5% with total NDKD in 55.2% and isolated DKD in 44.8% of patients. NDKD were glomerulonephritis(75%) with membranous nephropathy (25%) and IgA nephropathy (25%) patients. The significant difference between NDKD and isolated DKD was only the duration of diabetes 5 years in 81.2% patients with NDKD (p=0.018). DR was absent in 100% of patients with isolated NDKD, 80% of class III, and 62.5% of class IV DKD. Conclusion: NDKD is common in T2DM with renal involvement and regardless of retinopathy or duration of diabetes, kidney biopsy should be routinely performed in these patients with atypical clinical presentation.