Abstract:

ABSTRACT Objective: To investigate estimated GFR from combination of serum creatinine and cystatin C as marker to predict long-term renal outcome in patient with Type 2 diabetic nephropathy (DN). Methodology: Five hundred one patients with DN were enrolled in this study. The levels of eGFRcre, eGFRcys, eGFRcrecys were assessed at baseline, 12, and 24 month. After the follow-up time of median 31 months, the end-stage renal disease (ESRD) risk related to percentage change in estimated GFR over one and 2 years were compared to the three equations. Result: compared with eGFRcrecys, eGFRcre overestimated GFR in DN. The absolute bias was -0.21，6.17，12.69，9.55，5.27 ml/min/1.73m2 when eGFRcrecys>120 ml/(min.1.73m2), 90~120 ml/(min.1.73m2), 60~90 ml/(min.1.73m2), 30~60 ml/(min.1.73m2),<30ml/(min.1.73m2), respectively. Lower age, higher systolic blood pressure, lower body mass index, and increased fast blood glucose contributed to the bias. eGFRcrecys slope over 2 year was superior to eGFRcre or eGFRcys to predict renal outcome, whose area under curve ( AUC ) was 0.857 ±0.0297 and the ROC of eGFRcrecys slope over 2 year combined with baseline eGFRcrecys was further increased to 0.917± 0.0178. Baseline eGFRcrecys >90ml/(min.1.73m2), 57% reduction over 2 years as an alternative end point, the sensitivity and specificity was 100%; Baseline eGFRcrecys <90 ml/(min.1.73m2), 40% reduction over 2 years could be an idea alternative end point. Conclusion: eGFRcre overestimated GFR in the patients with DN, in particular eGFR less than 120ml/(min.1.73m2), 57% reduction over 2 years in baseline eGFRcrecys > 90ml/(min.1.73m2) and 40% reduction over 2 years in baseline eGFRcrecys < 90ml/(min.1.73m2) could be an idea alternative end point to predict ESRD.

Key words: cystatin C, glomerular filtration rate, type 2 diabetic nephropathy, CKD-EPI, renal prognosis