Retinol-Binding Protein 4 Predicts Lesion Volume (Determined by MRI) and Severity of Acute Ischemic Stroke

Retinol-binding protein 4 (RBP4) is an adipocyte-secreted molecule and is associated with cardiovascular risk factors. The aim of this study was to assess the clinical significance of serum levels of RBP4 in Chinese patients with acute ischemic stroke (AIS). We sequentially screened patients with first-ever AIS who were admitted to our Hospital between September 2016 and October 2017. Serum levels of RBP4 were assayed with solid-phase sandwich ELISA, and severity of stroke was evaluated with the National Institutes of Health Stroke Scale (NIHSS) score on admission. We used logistic regression models to assess the relationship between RBP4 levels and stroke risk and severity. During the inclusion period, 323 patients completed the study. Our results indicated that the median serum RBP4 levels were significantly (P < 0.001) higher in patients with AIS than in those normal cases [28.9 (IQR, 17.3-39.6) μg/ml vs. 23.7 (14.6-32.3) μg/ml]. In logistic regression analysis, for each 1 unit increase of serum level of RBP4, the unadjusted and adjusted risks of AIS increased by 4% (OR 1.04 [95% CI 1.02-1.05], P < 0.001) and 3% (1.03 [1.01-1.04], P < 0.001), respectively. At admission, 116 patients (35.9%) had a minor stroke (NIHSS < 6). In logistic regression analysis, for each 1 unit increase of serum level of RBP4, the unadjusted and adjusted risks of moderate-to-high stroke increased by 7% (OR 1.07 [95% CI 1.05-1.09], P < 0.001) and 5% (1.05 [1.02-1.07], P < 0.001), respectively. Elevated levels of RBP4 could be considered an independent diagnosis marker of AIS. Elevated levels of RBP4 were significantly associated with higher stroke severity in Chinese sample.