The association between serum adipocyte fatty acid-binding protein and 3-month disability outcome after aneurysmal subarachnoid hemorrhage

Background Adipocyte fatty acid-binding protein (FABP4) is an adipokine that plays an important role in development of cardiovascular and metabolic diseases. The aim of this study was to assess the 3-month prognostic value of serum levels of FABP4 in Chinese patients with aneurysmal subarachnoid hemorrhage (aSAH) on hospital admission. Methods This was a prospective observational study from a stroke treatment center in Zhengzhou, China. From October 2016 to May 2018, patients with aSAH who were hospitalized within 24 h were included. In addition, 202 age- and gender-matched healthy volunteers were assigned to the healthy control group. At admission, serum levels of FABP4 were measured, and patients' characteristics, Hunt-Hess grade, and modified Fisher grade evaluated. At 3-month follow-up, functional outcome (Glasgow Outcome Scale score; dichotomized as poor [score 1-3] or good [score 4-5]) and all-cause mortality were recorded. Univariate and multivariate logistic regression models were used to investigate the association of FABP4 with the two endpoints. Results A total of 418 patients with aSAH were included in this study. The median age was 58 years (interquartile range, 49-66 years), and 57.9% were women. FABP4 serum levels were related to Hunt-Hess score (r[Spearman] = 0.381; P < 0.001). Patients with a poor outcome and non-survivors had significantly increased serum FABP4 levels on admission (P < 0.001 for all). In multivariate logistic regression analysis, FABP4 was an independent predictor of poor outcome and mortality, with increased risks of 7% (odds ratios 1.07, 95% confidence interval [CI] 1.02-1.13; P = 0.001) and 5% (odds ratio 1.05, 95% CI, 1.01-1.12; P = 0.003), respectively. Receiver operating characteristics to predict functional outcome and mortality were significantly different between conventional risk factors (difference area under the curve 0.024, 95% CI 0.018-0.032) and FABP4 plus conventional risk factors (area under the curve 0.015, 95%CI 0.011-0.020). After FABP4 was added to the existing risk factors, mortality was better reclassified and was associated with the net reclassification improvement statistic (P = 0.009), while poor outcome was better reclassified and associated with both the integrated discrimination improvement and net reclassification improvement statistics (P < 0.05 for all). Conclusions Elevated serum FABP4 levels were related to poor outcome and mortality in a cohort of patients with aSAH.