Association of Urine Albumin-Creatinine Ratio and Cystatin C-Based Estimated GFR with Outcomes in Patients with Ischemic Stroke

Abstract

Background/Aims: Data about the independent and combined effects of cystatin C based estimated glomerular filtration rate (eGFRcys) and albuminuria on the risk of poor outcome in stroke patients is limited. The aim was to elucidate how these two renal markers affect the clinical outcomes after ischemic stroke separately and jointly. Methods: The study subjects consisted of 10,197 patients with ischemic stroke from the third China National Stroke Registry (CNSR-III). The study outcomes were all-cause mortality, post stroke disability, recurrence of stroke and cardiocerebral vascular disease (CVD) composite events. Cox proportional hazard models and multivariable logistic regression model were applied to evaluate the effects of eGFRcys and urine albumin–creatinine-ratio (ACR) on these outcomes. Results: Both reduced eGFRcys and increased ACR were independently associated with higher incidences of all-cause death and post stroke disability (p<0.01). Mildly decreased eGFRcys (60-89 mL/min/1.73 m2) is associated with increased risk of all-cause death and post stroke disability in the presence of high-normal ACR (10-29mg/g). Patients with both eGFRcys ＜45 mL/min/1.73 m2 and ACR ≥30mg/g at baseline had a 6.8-fold risk for all-cause mortality and 3.6-fold risk for post stroke disability, compared with patients with eGFRcys of 90-119 mL/min/1.73 m2 and ACR <10mg/g. In addition, increased ACR were associated with recurrent stroke and CVD composite event, while reduced eGFRcys showed no relationship with these outcomes. Conclusions: Both decreased eGFRcys and albuminuria are independent risk factors for all-cause death and post stroke disability. Combining the two markers is useful for improving risk stratification even in those without chronic kidney disease.