Significance of renal biopsy in patients with presumed diabetic nephropathy

Aims/Introduction Patients with diabetic nephropathy ( DN ) typically show varying degrees of proteinuria and renal impairment. Because these clinical signs are frequently observed in other glomerulopathies, renal biopsy is required to make a definitive diagnosis of DN . We carried out the present study to evaluate the significance of renal biopsy for patients who have been presumptively diagnosed with DN . Materials and Methods A total of 55 patients with type 2 diabetes mellitus ( DM ), and proteinuria, hematuria and/or renal impairment were enrolled in this study. Results Renal biopsy showed that just 30 patients (54.5%) were histologically diagnosed with DN . Fasting plasma glucose and glycated hemoglobin levels were associated with the presence of DN , whereas baseline renal function showed no statistically significant relationship to DN . The duration of DM was not associated with the presence of DN . Patients with DN had a higher rate of diabetic retinopathy ( DR ) than those with non‐ DN ( DN 18 patients vs non‐ DN three patients, P  = 0.00029). DN patients with DR showed a more severe renal histology than those without. Conclusions These data suggest that, even for patients with long‐term DM , renal biopsy should be carried out in patients with presumed DN . Because treatment options differ between DN and primary glomerulopathies, renal biopsy should especially be considered for presumed DN without DR .