以血清肌酸酐與胱蛋白C合併估算腎絲球過濾速率（GFR）評估糖尿病病人其腎功能之預後

Combine Serum Cystatin C and Creatinine to Estimate Glomerular Filtration Rate (GFR) for the Prognostic Evaluation of Kidney Function in Diabetes

糖尿病併發慢性腎病主要依據血清肌酸酐MDRD公式估算腎絲球過濾速率（eGFR MDRDcreat）作嚴重度分期，目前已知有許多生理因素會影響其準確性。本研究分析，增加偵測血清胱蛋白CCKD-EPI公式估算腎絲球過濾速率（eGFR CKD-EPIcys）或結合血清肌酸酐及胱蛋白C CKD-EPI公式估算腎絲球過濾速率（eGFR CKD-EPIcreat-cys），能否幫助糖尿病病患的腎功能評估。結果顯示，除現行的eGFR MDRDcreat外，對於腎病第2期及第3期的病患，若增加檢測eGFRCKD-EPIcys，可以幫助分辨出腎功能惡化或腎衰竭高危險性的病人，提早採取更積極的預防及治療。

There are multiple physical factors interfere with the accuracy of estimated glomerular filtration rate derived from serum creatinine-based Modification of Diet in Renal Disease formula (eGFR MDRDcreat). In this study, we examined whether by adding further stageing with eGFR derived from serum cystatin C-based Chronic Kidney Disease Epidemiology Collaboration formula (eGFR CKD-EPIcys) or eGFR derived from serum creatinine-cystatin C-based CKD-EPI formula (eGFR CKD-EPIcreat-cys) will improve the prognostic evaluation of kidney function. A total of 380 diabetic patients were followed (mean=5.6 years) for developing a CKD progresssion or kidney failure. Patients were staged by baseline eGFR MDRDcreat. By using eGFR CKD-EPIcys and eGFR CKD-EPIcreat-cys, 200 and 145 patients could be further reclassified into different stages respectively. For either outcome, reclassification of patients with G2 or G3 stage by eGFR CKD-EPIcys into a worse stage was associated with higher incident rate whereas those reclassified into a better stage was associated with lower incidnet rate. However, the improvement of prognostic evaluation of kidney function by reclassification with eGFR CKD-EPIcreat-cys was limited to G3 stage patients. In conclusion, our findings suggest that adding further CKD staging by eGFR CKD-EPIcys will help to improve the prognostic evaluation of kidney function in diabetic patients.