Clinicopathologic features and prognostic factors in older patients with biopsy-proven diabetic nephropathy

Purpose The older population has increased sharply in China. However, renal clinical and histopathological data in this population are lacking. This study investigated the clinicopathologic features and the related risk factors for long-term renal survival in older patients with diabetic nephropathy (DN). Methods In this retrospective observational study, 74 older patients (≥ 60 years old) with type 2 diabetes mellitus and biopsy-proven DN from 2007 to 2019 were included. Clinical data were extracted from electronic records. Renal biopsy specimens were semiquantitatively evaluated using the Renal Pathology Society (RPS) classification system. Cox proportional hazard analysis was used to estimate hazard ratios (HRs) for progression to end-stage renal disease (ESRD). Results During the median follow-up period of 22 months, 24 (32%) older patients progressed to ESRD. Older patients who progressed to ESRD had poorer renal function, lower hemoglobin and albumin concentrations, more severe glomerular lesions, and higher percentages of Kimmelstiel–Wilson lesions than those who did not progress to ESRD. After adjusting for age, sex, baseline renal function, and pathological parameters, multivariate Cox proportional hazard analysis showed that RPS glomerular classification (HR 2.49, 95% confidence interval [CI] 1.03–6.04), estimated glomerular filtration rate (eGFR) (HR 0.76, 95% CI 0.58–0.99), and proteinuria (HR 3.85, 95% CI 1.44–10.27) were independent risk factors for progression to ESRD. Conclusion Lower eGFR, heavier proteinuria, and more severe RPS glomerular lesions were associated with ESRD in older patients with type 2 diabetes mellitus and DN.