Background: The patients with Type 2 diabetes mellitus (T2DM) and diabetic retinopathy (DR) are prone to develop diabetic nephropathy (DN). In this study, we aimed to clarify the relationship between DR and the progression of DN in patients with T2DM.
Methods: In the cross-section study, 250 patients with T2DM and biopsy-proven DN were divided into two groups: 130 in the DN without DR group (DN group) and 120 in the DN + DR group. Logistic regression analysis was performed to identify risk factors for DR. Of the above 250 patients, 141 were recruited in the cohort study who received follow-up for at least 1 year and the influence of DR on renal outcome was assessed using Cox regression. Renal outcome was defined as the progression to end-stage renal disease (ESRD).
Results: In the cross-section study, the severity of glomerular lesions (class IIb + III) and DM history >10 years were significantly associated with the odds of DR when adjusting for baseline proteinuria, hematuria, e-GFR, and interstitial inflammation. In the cohort study, a multivariate COX analysis demonstrated that the DR remained an independent risk factor for progression to ESRD when adjusting for important clinical variables and pathological findings (p < .05).
Conclusions: These findings indicated that the severity of glomerular lesions was significantly associated with DR and DR was an independent risk factor for the renal outcomes in patients with DN, which suggested that DR may predict the renal prognosis of patients with T2DM and DN.
Keywords: Diabetic nephropathy; diabetic retinopathy; renal outcomes; renal pathology; risk factors.