Age- and gender-adjusted estimated glomerular filtration rate definition reveals hyperfiltration as a risk factor for renal function deterioration in type 2 diabetes

Abstract

Aim: To assess the role of hyperfiltration for diabetic kidney disease (DKD) progression.

Materials and methods: A retrospective observational cohort study enrolled type 2 diabetes (T2D) patients with an initial estimated glomerular filtration rate (eGFR) of 60 mL/min/1.73m² or higher. Patients were categorized into two groups: hyperfiltration (eGFR exceeding the age- and gender-specific 95th percentile values from a prior national cohort study) and normofiltration. Rapid DKD progression was defined as an eGFR decline of more than 5 mL/min/1.73m²/year. We used a linear mixed effect model and Cox regression with time-varying covariate model to compare eGFR changes and identify factors associated with rapid DKD progression.

Results: Of the enrolled 7563 T2D patients, 7.2% had hyperfiltration. The hyperfiltration group exhibited a higher rate of eGFR decline compared with the normofiltration group (-2.0 ± 0.9 vs. -1.1 ± 0.9 mL/min/1.73m²/year; P < .001). During an average follow-up period of 4.65 ± 3.86 years, 24.7% of patients with hyperfiltration experienced rapid DKD progression, compared with 15.7% of patients with normofiltration (P < .001). Cox regression analyses identified that initial hyperfiltration was a significant determinant of rapid DKD progression, with a hazard ratio of 1.66 (95% confidence interval: 1.41-1.95; P < .001). When combined with albuminuria, the risk of progression was further compounded (hazard ratio 1.76-3.11, all P < .001).

Conclusions: In addition to using the current Kidney Disease: Improving Global Outcomes CGA classification system, considering glomerular hyperfiltration status can improve the accuracy of predicting DKD progression.

Keywords: cohort study; diabetes complications; diabetic nephropathy; real‐world evidence.