Renal pathological change in patients with type 2 diabetes is not always diabetic nephropathy: a report of 52 cases

The present study examined the relationship between clinical features and renal histological changes in the Type 2-diabetic patients and evaluated the usefulness of renal biopsy in the diagnosis of diabetic versus non-diabetic kidney disease.

52 patients with Type 2-diabetic mellitus were retrospectively analyzed for differential clinical, laboratory features and pathological characteristics including overt proteinuria (> 0.5 g/day), elevated serum creatinine and/or the development of hematuria.

Of 52 patients, 20 cases (38.5%) showed no detectable diabetic lesions and, thus, were diagnosed as non-diabetic renal disease (NDRD), while 32 patients (61.5%) exhibited diabetic nephropathy. Interestingly, while 29 patients showed diabetic nephropathy (DN) alone, NDRD was also found in 3 patients with DN. Clinically, 24 out of 52 patients (46.16%) had a diagnosis consistent with the pathological findings, while 10 (19.23%) were diagnosed incorrectly. Compared to NDRD patients, patients with DN had prolonged diabetic history with or without retinopathy, while 25% of patients with NDRD exhibited mesangial proliferative glomerulonephritis.

NDRD was a common feature in Type 2-diabetic patients with renal involvement. The absence of retinopathy and short periods of diabetic history may be useful indicators for diagnosis of NDRD clinically.