Association of high sensitive C-reactive protein with stroke: a prospective follow-up study

Objective To investigate an optimal cut-off value of high sensitivity C-reactive protein (hs-CRP) for the prediction of ischemic stroke in Yixing population and to explore the association between hs-CRP level and the risk of ischemic stroke. Methods A total of 2 238 participants over 35 years old were investigated in a rural area (Guanlin, Yixing, Jiangsu; from May to September 2009) using an epidemiological cluster sampling approach. A total of 2 211 participants were followed (median follow-up time was 5.07 person years) after excluding those who had history of ischemic stroke or cardiovascular disease and those whose disease history was incompleted and those who failed to be detected hs-CRP level. Fitted with survival receiver operator characteristic (ROC) curve in which hs-CRP level predicts the incidence of stroke, the optimal cut-off point was determined according to the maximum Youden's index. Cox proportional hazard model was applied to detect the association between hs-CRP level and the incidence of stroke. Results A total of 96 participants developed ischemic stroke in the period of follow-up. The Youden's index reached the maximum (0.270) when the area under ROC curve was 0.647 and the level of hs-CRP was 1.17 mg/L accordingly. The result of symmetric measure showed that predictive incidences of stroke based on the levels of hs-CRP ≥ 1.17 mg/L and ≥ 1.00 mg/L were consistent. Cox regression analyses showed a significant association of high hs-CRP(≥ 1.00 mg/L) with the risk of incident ischemic stroke even after adjusting for the covariates including age, gender, BMI, GLU, HDL-C, LDL-C, TC, TG, smoking and drinking, and hypertension and T2DM (HR=2.238, 95% CI:1.388-3.608,P=0.001). Conclusions Hs-CRP ≥ 1.00 mg/L is appropriate for predicting the incidence of stroke and intervening with the high risk population in Yixing population.