Tian Linwei, Qiu Hong, Pun Vivian C, Ho Kin-Fai, Chan Chi Sing, Yu Ignatius T S
School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, China.
School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, China.
Int J Cardiol. 2015 Dec 15;201:4-9. doi: 10.1016/j.ijcard.2015.07.099. Epub 2015 Aug 1.
Recent experimental and clinical studies suggested that exogenous carbon monoxide (CO) at low concentrations may have beneficial neuroprotective effects under certain circumstances. However, population-based epidemiological studies of environmentally relevant CO exposure generated mixed findings. The present study aimed to examine the short-term association of ambient CO with emergency stroke hospitalizations.
A time series study was conducted. Daily air pollution concentrations and emergency hospital admission data from January 2004 to December 2011 in Hong Kong were collected. Generalized additive Poisson models were used to estimate the associations between daily 24-hour mean concentrations of CO and emergency hospital admissions for stroke, while controlling for other traffic related co-pollutants: NO₂ and PM₂.₅. Sensitivity analyses were performed using daily 1-hour maximum concentration of CO as exposure indicator.
Negative associations were observed between ambient CO concentrations and emergency hospital admissions for stroke. The previous 1-3 day cumulative exposure to CO was associated with a -2.0% (95%CI, -3.3% to -0.7%) decrease in stroke admissions per interquartile range (IQR) increment in CO concentration (0.3 ppm). Similar results were obtained when using 1-hour maximum concentration of CO as exposure indicator. The negative association was robust to the co-pollutant adjustment for either NO₂ or PM₂.₅. Females and elders appeared to be more sensitive to ambient CO exposure. The negative association tended to be larger in cool season.
Short-term exposure to ambient CO was associated with decreased risk of emergency hospitalizations for stroke, suggesting some acute protective effects of CO exposure against stroke onsets.
近期的实验和临床研究表明，低浓度的外源性一氧化碳（CO）在某些情况下可能具有有益的神经保护作用。然而，基于人群的环境相关CO暴露的流行病学研究结果不一。本研究旨在探讨环境CO与急诊中风住院之间的短期关联。
进行了一项时间序列研究。收集了2004年1月至2011年12月香港的每日空气污染浓度和急诊入院数据。使用广义相加泊松模型来估计每日24小时平均CO浓度与中风急诊入院之间的关联，同时控制其他与交通相关的共污染物：二氧化氮（NO₂）和细颗粒物（PM₂.₅）。使用每日1小时最大CO浓度作为暴露指标进行敏感性分析。
观察到环境CO浓度与中风急诊入院之间存在负相关。CO浓度每增加一个四分位数间距（IQR）（0.3 ppm），前1 - 3天累积暴露于CO与中风入院率降低-2.0%（95%置信区间，-3.3%至-0.7%）相关。使用1小时最大CO浓度作为暴露指标时也获得了类似结果。这种负相关在对NO₂或PM₂.₅进行共污染物调整后仍然稳健。女性和老年人似乎对环境CO暴露更敏感。在寒冷季节，这种负相关往往更大。
短期暴露于环境CO与中风急诊住院风险降低相关，表明CO暴露对中风发作具有一定的急性保护作用。
