Renal outcomes and prognostic factors in patients with type-2 diabetes and chronic kidney disease confirmed by renal biopsy

AIM: To evaluate the renal outcomes and prognostic factors among patients with type-2 diabetes (T2D) and biopsy-confirmed diabetic nephropathy (DN), non-diabetic renal disease (NDRD) and DN mixed with NDRD (MIX). DESIGN AND METHODS: Patients with both T2D and chronic kidney disease (CKD) who underwent renal biopsy between January 2014 and December 2016 were recruited in this prospective observational study. Participants were divided into DN group, NDRD group, or MIX group according to the baseline pathological diagnosis. The primary endpoint was a composite renal event of end-stage renal disease (ESRD) or ⩾ 40% reduction in estimated glomerular filtration rate (eGFR). RESULTS: Among the 292 participants included, 153 (52.4%) belonged to the DN group, 30 (10.3%) belonged to the NDRD group, and 109 (37.3%) belonged to the MIX group. During the median follow-up of 27 months, the adverse renal events occurred in 132 (44.2%) patients. Compared with NDRD group, the multiple adjusted hazard ratios (HRs) for renal events in patients with DN and MIX groups were 3.900 (95% confidence interval [CI]: 1.103–13.788) and 2.691 (95% CI: 0.662–10.936), respectively. Baseline lower eGFR (HR: 1.159, 95% CI: 1.060–1.266), severe proteinuria (HR: 2.047, 95% CI: 1.227–3.416), lower hemoglobin (HR: 1.170, 95% CI: 1.008–1.267), and a family history of diabetes (HR: 1.138, 95% CI: 1.008–2.285) were independent predictors for adverse renal outcomes in patients with DN. CONCLUSION: In patients with T2D and CKD, pure DN and MIX group displayed a worse renal prognosis than NDRD group. Worse renal function, severe proteinuria, lower hemoglobin, and a family history of diabetes may be associated with adverse renal outcomes in patients with DN.