Renal Histology in Diabetic Patients

BACKGROUND: The diagnosis of diabetic nephropathy is based on the course of clinical manifestations and renal biopsy. Renal biopsy is usually performed in patients with atypical presentations. OBJECTIVES: This study was performed to analyze various renal histopathological lesions in diabetic patients and to establish a clinicopathological correlation. MATERIALS AND METHODS: In this retrospective study, the authors analyzed renal histology of 40 patients with type 2 diabetes mellitus who presented with atypical features of diabetic renal involvement and underwent renal biopsy at the Military Hospital Mohammed V, Rabat, Morocco, between January 2008 and December 2016. RESULTS: About 60% of the patients had isolated diabetic nephropathy, 35% had isolated nondiabetic renal diseases and 5% had both. Patients with nondiabetic renal diseases had significantly higher hematuria (P = 0.02), shorter duration of diabetes (P = 0.009), higher mean estimated glomerular filtration rate (P = 0.04) and lower prevalence of diabetic retinopathy (P < 0.001). The most common histological lesion in patients with nondiabetic renal diseases was IgA nephropathy (25%). In patients with diabetic nephropathy, the most common histological class was Class III (42.3%). Furthermore, higher histological classes were associated with lower estimated glomerular filtration rate (P < 0.001) as well as higher prevalence of diabetic retinopathy (P = 0.009) and nephrotic proteinuria (P = 0.04). CONCLUSIONS: This study found that in Rabat, Morocco, the most common histopathological lesion in patients with diabetes was diabetic nephropathy. Hematuria, shorter duration of diabetes, higher mean estimated glomerular filtration rate and lower prevalence of diabetic retinopathy were reported among those with nondiabetic renal diseases. These findings are in accord with that of studies from other countries. However, large sample size and long-term follow-up clinical studies are needed to demonstrate the renal pathological implications and renal outcomes in type 2 diabetes mellitus patients with renal involvement.