Introduction:
Diabetic nephropathy (DN) is the leading cause of end-stage renal disease (ESRD) worldwide, largely due to the increasing prevalence of type 2 diabetes mellitus (DM). Factors such as glomerular hyperfiltration, capillary hypertension, and chronic hyperglycaemia, with podocyte injury, play a key role in kidney damage. However, non- diabetic renal diseases (NDRD) often present similarly to DN and are frequently underdiagnosed. A considerable number of diabetic patients may have NDRD, which challenges the common attribution of proteinuria or renal failure solely to DN. This study aims to distinguish between DN and NDRD using renal biopsy, highlighting the importance of accurate diagnosis for effective treatment and better patient outcomes
Methods:
This retrospective analysis included 115 renal biopsies from type 2 DM patients at our centre from January 2019 to August 2024, excluding renal transplant recipients and insufficient samples. DN was categorised using the Renal Pathological Society (RPS) classification, identifying mesangial expansion, glomerulosclerosis, and basement membrane thickening. Patients were grouped into isolated NDRD, NDRD superimposed on DN and isolated DN. Clinical parameters such as age, sex, DM duration, hypertension, retinopathy, serum creatinine, haematuria, and proteinuria were collected. Nephrotic syndrome, acute kidney injury, haematuria, chronic kidney disease, rapidly progressive renal failure, and hypertension were defined based on standard criteria.
Results:
A total of 115 diabetic patients were enrolled in this study. The mean age was 49.9 years (SD ± 10.1), with 60% being male. The median diabetes duration was 5 years (IQR: 4- 8). Diabetic retinopathy was present in 25.2% of participants. Diabetic kidney disease (DKD) was found in 33.9% (39/115), non-diabetic renal disease (NDRD) in 38.3% (44/115), and combined pathologies in 27.8% (32/115). DKD was more prevalent in males (66.7%), while NDRD was more common in females (54.5%). Females had a higher risk of NDRD (AOR = 2.796, p = 0.016). Diabetes duration over 5 years did not significantly affect NDRD risk (AOR= 0.810, p = 0.668). Retinopathy presence significantly reduced the risk of NDRD (AOR = 0.138, p = 0.005).
Table 1 Type of Kidney Disease Based on Biopsy
Table 2 Indication for Biopsy in Study Participants
Table 3 Histological subtypes in the isolated nondiabetic renal disease (NDRD) group
Table 4 Distribution based on type of renal disease
Table 5 Bivariate and Multivariate Analysis for association with non-diabetic renal disease (NDRD)
Bivariate Analysis Multivariate Analysis
Conclusions:
A significant portion of diabetic patients, especially those without retinopathy, were diagnosed with NDRD by kidney biopsy.The study emphasizes the necessity of considering biopsy for accurate diagnosis and management, particularly in atypical cases or the absence of retinopathy.
I have no potential conflict of interest to disclose.
I did not use generative AI and AI-assisted technologies in the writing process.