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/1.73m 2 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/1.73m 2 /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/1.73m 2 /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.