Total white blood cell count or neutrophil count predict ischemic stroke events among adult Taiwanese: report from a community-based cohort study

BACKGROUND Evidence about whether white blood cell (WBC) or its subtypes can act as a biomarker to predict the ischemic stroke events in the general population is scanty, particularly in Asian populations. The aim of this study is to establish the predictive ability of total WBC count or subtypes for long-term ischemic stroke events in the cohort population in Taiwan. METHODS The Chin-Shan Community Cohort Study began from 1990 to 2007 by recruiting 1782 men and 1814 women of Chinese ethnicity. Following a total of 3416 participants free from ischemic stroke events at baseline for a median of 15.9 years; we documented 187 new incident cases. RESULTS The multivariate relative risk for the comparison of the participants in the fifth and first WBC count quintiles was 1.67 (95% confidence interval [CI], 1.02-2.73; P for trend=0.03), and the corresponding relative risk for neutrophil count was 1.93 (95% CI, 1.13-3.29; P for trend=0.02). The discriminative ability by WBC and neutrophil counts were similar (area under the receiver operating characteristic curve, 0.600 for adding WBC, 0.610 for adding neutrophils, 0.595 for traditional risk factor model). In addition, the net reclassification improvement (NRI) values between the neutrophil and white blood cell count models were not significant (NRI, =-2.60%, P=0.35), indicating the similar discrimination performance for both WBC and neutrophil counts. CONCLUSIONS WBC and neutrophil count had a similar ability to predict the long-term ischemic stroke events among Taiwanese.