Superimposed FSGS Lesions Worsen Kidney Prognosis in Diabetic Nephropathy.

BACKGROUND

Diabetic nephropathy is one of the leading causes of kidney failure worldwide. However, the impact of histopathological lesions like focal and segmental glomerulosclerosis (FSGS) on kidney survival has been insufficiently evaluated. This study aimed to assess the effect of FSGS lesions on kidney outcomes in patients with diabetic nephropathy.

METHODS

We conducted a retrospective study of patients with biopsy-confirmed DN between 2010 and 2022. Exclusion criteria included kidney failure at presentation, primary glomerulopathies, metastatic cancer, pregnancy, organ transplantation, or inadequate follow-up. The primary outcome was progression to kidney failure. Kidney survival was analyzed using Kaplan-Meier methods, and predictors of kidney failure were identified through Cox regression.

RESULTS

A total of 67 patients met inclusion criteria. Mean age was 62 years; 57% were male, and 55% had FSGS lesions. Compared with those without FSGS, affected patients were more likely to be of non-White ethnicity (p=0.009), had higher urine albumin-to-creatinine ratios (p=0.01), greater interstitial fibrosis and tubular atrophy (p=0.009), and higher prevalence of class IV DN (p=0.04). 26 patients (39%) progressed to kidney failure. One-year kidney survival was 87% (95% CI: 79-95%), with poorer outcomes in the FSGS group (p=0.04). In multivariable analysis, FSGS (HR 2.9; 95% CI 1.18-7.12), stroke (HR 5.02; 95% CI 1.80-14.05), and serum albumin (HR 0.34; 95% CI 0.18-0.62) were independently associated with kidney failure.

CONCLUSION

Superimposed FSGS in diabetic nephropathy is associated with a higher risk of progression to kidney failure. These findings highlight the prognostic importance of histopathological evaluation in diabetic kidney disease.