Neutrophil-to-lymphocyte ratio predicts stroke-associated pneumonia

Abstract

Objective To investigate the predictive value of peripheral blood neutrophil-to-lymphocyte ratio (NLR) for stroke-associated pneumonia (SAP) in patients with acute stroke. Methods Consecutive patients with acute stroke were enrolled. Their clinical data were collected. The peripheral blood white blood cells, neutrophil and lymphocyte counts were detected within 24 h after admission, and the NLR was calculated. Multivariate logistic regression analysis was used to determine the independent correlation between NLR and SAP. The receiver operating characteristic (ROC) curve was used to analyze the predictive value of NLR for SAP. Results A total of 126 patients with acute stroke were enrolled, including 45 females (35.7%) and 81 males (64.3%). Their mean age was 64.8 years. Fifty-two patients (41.3%) had intracerebral hemorrhage, and 74 (58.7%) had ischemic stroke. Thirty-nine patients (31.0%) occurred SAP, and 87 (69.0%) did not occur SAP. Univariate analysis showed that age, National Institutes of Health Stroke Scale scores, fasting glucose, total white blood cell count, neutrophil count, NLR, and proportions of patients with hyperlipidemia, ischemic heart disease, atrial fibrillation, smoking, dysphagia, using acid suppressing drugs and indwelling gastric tube in the SAP group were significantly higher than those in the non-SAP group (all P<0.05), and the high-density lipoprotein cholesterol level and lymphocyte count in the SAP group were significantly lower than those in the non-SAP group (all P<0.05). Multivariate logistic regression analysis showed that NLR (odds ratio 2.079, 95% confidence interval 1.174-3.194; P=0.001) was an independent risk factor for SAP after adjustment for confounding factors. ROC curve analysis showed that when the NLR cutoff value was 6.765, the sensitivity of predicting SAP was 64.1%, the specificity was 73.6%, and the area under ROC curve was 0.721 (95% confidence interval 0.630-0.813). Conclusions The elevated NLR in peripheral blood within 24 h after admission may has a certain predictive value for SAP in patients with acute stroke. Key words: Stroke; Brain Ischemia; Pneumonia; Neutrophils; Lymphocytes; Risk Factors; Predictive Value of Tests