Association between serum cystatin C level and post‐stroke cognitive impairment in patients with acute mild ischemic stroke

BACKGROUND: Mild ischemic stroke (MIS) has been proved to be closely related to post‐stroke cognitive impairment (PSCI). However, there are relatively few studies on the risk factors of MIS. We aimed to evaluate the relationship between serum cystatin C (CysC) level and cognitive function in patients with acute MIS. METHODS: Four hundred consecutive patients with acute MIS were screened and 281 patients were eligible for this study. The serum CysC levels were detected within 24 h after admission. Cognitive function was assessed by Montreal Cognitive Assessment (MoCA) at 3 months after acute MIS. Logistic regression was used to identify the predictors of PSCI, and the receiver operating characteristic (ROC) curve was applied to explore the optimal cut‐off value. RESULTS: One hundred sixty‐four (58.4%) patients were diagnosed with PSCI at 3 months follow‐up. The serum CysC levels in patients with PSCI were significantly higher than patients without PSCI (p < .001). The binary logistic regression analysis showed that higher serum CysC level was an independent predictor for PSCI at 3 months (odds ratio [OR], 5.745; 95% confidence interval, [CI], 1.089–30.311; p = 0.039). The ROC curve showed that area under the curve (AUC) was 0.723, and at a 0.945 mg/l CysC cut‐off point, the sensitivity and specificity for PSCI at 3 months were 79.9% and 58.1%, respectively. CONCLUSION: Our findings suggested that the serum CysC levels were increased after acute MIS, and higher serum CysC levels at baseline might be an independent risk factor for PSCI in patients with acute MIS, but further research are warranted.