High Plasma Glutamate Levels are Associated with Poor Functional Outcome in Acute Ischemic Stroke

The aim of the present study was to investigate the relationship between acute ischemic stroke and glutamate levels and to determine the prognosis value of plasma glutamate levels to predict the functional outcome. Two hundred and forty-two patients with acute ischemic stroke and 100 sex- and age-matched controls were included in the study. Plasma glutamate levels were determined by HPLC at admission in both groups. Stroke severity was assessed using the National Institutes of Health Stroke Scale (NIHSS). The modified Rankin Scale (mRS) scores at 3 months was determined to outcomes, and unfavorable outcomes were defined as mRS at 3–6. The prognostic value analyzed by logistic regression analysis, after adjusting for the possible confounders. In the 94 patients with an unfavorable functional outcome, plasma glutamate levels were higher compared with those in patients with a favorable outcome [221(IQR, 152–321) μM; 176(IQR, 112–226) μM, respectively; P < 0.0001). In multivariate logistic regression analysis, glutamate was an independent predictor of functional outcome, with an adjusted OR of 6.99 (95 % confidence interval [CI] 2.21–21.23). Receiver operating characteristics to predict functional outcome demonstrated areas under the curve of glutamate of 0.821 (95 % CI 0.733–0.878; P < 0.0001) and combined model (glutamate and NIHSS) improved the NIHSS score alone. Plasma glutamate levels can be seen as an independent short-term prognostic marker of functional outcome in Chinese patients with acute ischemic stroke even after correcting for possible confounding factors.