The predictive value of serum uric acid in the outcome of traumatic brain injury

Abstract

Objective To investigate the predictive value of serum uric acid for patients with traumatic brain injury.Methods A total of 330 patients with traumatic brain injury (Glasgow Coma Scale score,GCS:3-14) admitted to the First Affiliated Hospital of Soochow University between November 2010 and October 2012 were enrolled.They were divided into a survival group (GOS:2-5) and a non-survival group (GOS:1).The levels of serum uric acid were measured from venous blood in the morning of the second day after admission.Clinical data were analyzed by logistic regression model,spearman correlation,and ROC curve analysis.Results Spearman correlation analysis showed that serum uric acid was significantly correlated with GCS (r =-0.270 1,P =0.000) and GOS (r =-0.251 2,P =0.000).Age,GCS,pupil reaction and serum uric acid were determined as independent predictors for death by logistic model.The adjusted OR of uric acid was 1.0048,(95％ CI:1.001 9-1.007 6,P =0.001).The area under the ROC curve was 0.718,(95％ CI:0.666-0.766),the optimal cut-off value determined by the Youden index was 304 μmol/L (sensitivity:60.24％,specificity:78.14％,correctly classified:73.64％).In the core model (Age + GCS + Pupil reaction),theR2 value was 0.476 4.With uric acid added into,the predictive power of the model increased to R2 =0.510 5 (7.2％ increased).Conclusions The level of serum uric acid is significantly correlated with the severity of TBI and could be used as an independent predictor for death. Key words: Traumatic brain injury; Uric acid; Prognosis; Risk factor