Renal Function and Proteinuria as Indicators of Adverse Outcomes in Biopsy-Confirmed Diabetic Kidney Disease

Abstract

Diabetic kidney disease (DKD) is a major cause of chronic kidney disease and adverse renal outcomes. Renal function and proteinuria are routinely assessed markers, but their prognostic importance in biopsy-confirmed DKD requires further evaluation. To assess renal function and proteinuria, compare these parameters between patients with and without adverse outcomes and determined their association with adverse clinical outcomes in biopsy-confirmed DKD. A retrospective secondary-data-based observational study was conducted using a publicly available dataset of 168 patients with biopsy-confirmed DKD. Renal function markers included estimated glomerular filtration rate (eGFR), serum creatinine, and blood urea nitrogen, while proteinuria was assessed using 24-hour urinary protein and urinary microalbumin. Adverse outcome was defined as a composite of all-cause mortality, initiation of regular dialysis, or renal transplantation. Descriptive statistics, independent-samples t-test, chi-square test, correlation analysis, and logistic regression were applied. Patients with adverse outcomes showed significantly lower eGFR and higher serum creatinine, blood urea nitrogen, 24-hour urinary protein, and urinary microalbumin. eGFR was negatively correlated with proteinuria, while serum creatinine showed positive correlations with urinary protein measures. Univariate regression identified several renal markers and serum albumin as significant factors. In multivariable analysis, eGFR remained independently associated with adverse outcome, while 24-hour urinary protein lost statistical significance after adjustment. Serum albumin also remained independently protective. Reduced renal function and increased proteinuria were associated with adverse outcomes in biopsy-confirmed DKD, with eGFR emerging as the strongest independent renal indicator.

Keywords: Diabetic kidney disease; eGFR; Proteinuria; Renal function; Adverse outcomes