Analysis of clinical manifestations and outcomes of idiopathic membranous nephropathy compared with diabetic nephropathy in patients with type 2 diabetes

Objective To evaluate the predictive factors and renal outcomes of idiopathic membranous nephropathy (IMN) in patients with type 2 diabetes (T2DM). Methods In this retrospective study, clinical data of 101 IMN patients with T2DM and 96 patients with diabetic nephropathy (DN) were consecutively collected. Logistic regression was used to assess potential clinical factors indicating IMN and COX regression was employed to analyze risks of IMN in developing to end-stage renal disease (ESRD), as compared with that of DN, in patients with T2DM. Results In a multivariate model, age≥55 years old, presence of nephrotic syndrome, estimated glomerular filtration rate (eGFR)＞60 ml?min-1?(1.73 m2)-1, duration of diabetes≤5 years and absence of diabetic retinopathy, were associated with IMN, as compared with DN, in patients with T2DM. In T2DM patients presented with nephrotic syndrome, age≥55 years old, eGFR＞60 ml?min-1?(1.73 m2)-1, duration of diabetes≤5 years and absence of diabetic retinopathy, were also associated with IMN, as compared with DN. Receiver operating characteristic curve (ROC) showed eGFR 65.5 ml?min-1?(1.73 m2)-1 was an optimal cutoff in differentiating DN and IMN. DN was associated with 16.8 times as high risk of incident ESRD as compared with IMN in T2DM patients. Conclusions In patients with T2DM, age≥55 years, presence of nephrotic syndrome, early stage of CKD, duration of diabetes≤5 years and absence of retinopathy, may indicate IMN rather than DN. T2DM patients with IMN have much better renal prognosis as compared with DN.