UNIFAI, Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, Porto, Portugal.
Cerebrovasc Dis. 2011;32(6):542-51. doi: 10.1159/000331473. Epub 2011 Nov 18.
Changes in meteorological parameters have been associated with cardiovascular mortality and stroke. The high incidence of stroke in Portugal may be modelled by short- or long-term weather changes whose effect may be different across stroke types and severity.
Data include all patients with a first-ever-in-a-lifetime stroke registered in a population of 86,023 residents in the city of Porto from October 1998 to September 2000. Specific stroke types were considered and ischaemic stroke (IS) subtype was defined according to the Oxfordshire Community Stroke Projet classification and the Trial of Org 10172 in Acute Stroke Treatment (TOAST) criteria. Information on daily temperature, humidity and air pressure was obtained from the National Meteorological Office. The Poisson distribution was used to model the daily number of events as a function of each weather parameter measured over different hazard periods, and the binomial model to contrast effects across subgroups. Differential effects of meteorological parameters and hazard periods upon stroke occurrence and outcome were analysed in a stepwise model.
Among the 462 patients registered, 19.6% had a primary intracerebral haemorrhage (PICH) and 75.3% an IS. Among patients with IS, 21.6% were total anterior circulation infarcts (TACIs), 19.8% partial anterior circulation infarcts (PACIs), 19.5% posterior circulation infarcts (POCIs) and 39.1% were lacunar infarcts (LACIs). The aetiology of IS was large artery atherosclerosis in 6.9%, cardioembolism in 23.3% and small artery occlusion in 35.6%. The incidence of PICH increased by 11.8% (95% CI: 3.8-20.4%) for each degree drop in the diurnal temperature range in the preceding day. The incidence of IS increased by 3.9% (95% CI: 1.6-6.3%) and cardioembolic IS by 5.0% (95% CI: 0.2-10.1%) for a 1°C drop in minimum temperature in the same hazard period. The incidence of TACIs followed the IS pattern while for PACIs and POCIs there were stronger effects of longer hazard periods and no association was found for LACIs. The relative risk of a fatal versus a non-fatal stroke increased by 15.5% (95% CI: 6.1-25.4%) for a 1°C drop in maximum temperature over the previous day.
Outdoor temperature and related meteorological parameters are associated with stroke occurrence and severity. The different hazard periods for temperature effects and the absence of association with LACIs may explain the heterogeneous effects of weather on stroke occurrence found in community-based and hospital admission studies. Emergency services should be aware that specific weather conditions are more likely to prompt calls for more severe strokes.
气象参数的变化与心血管死亡率和中风有关。葡萄牙中风高发可能与短期或长期天气变化有关，其影响可能因中风类型和严重程度的不同而不同。
本研究数据包括 1998 年 10 月至 2000 年 9 月期间，波尔图市 86023 名居民中首次发生终生性中风的所有患者。考虑了特定的中风类型，根据牛津社区中风项目分类和急性中风治疗组织 10172 试验（TOAST）标准，定义了缺血性中风（IS）亚型。每天的温度、湿度和气压信息从国家气象办公室获得。使用泊松分布来模拟每天事件数量作为不同危险期内测量的每个气象参数的函数，使用二项式模型来对比不同亚组的效果。在逐步模型中分析气象参数和危险期对中风发生和结局的差异影响。
在登记的 462 名患者中，19.6%为原发性颅内出血（PICH），75.3%为 IS。在 IS 患者中，21.6%为完全前循环梗死（TACI），19.8%为部分前循环梗死（PACIs），19.5%为后循环梗死（POCI），39.1%为腔隙性梗死（LACI）。IS 的病因是大动脉粥样硬化占 6.9%，心源性栓塞占 23.3%，小动脉闭塞占 35.6%。在前一天，日间温度范围每下降 1 度，PICH 的发病率增加 11.8%（95%CI：3.8-20.4%）。在同一危险期内，IS 发病率增加 3.9%（95%CI：1.6-6.3%），心源性栓塞性 IS 增加 5.0%（95%CI：0.2-10.1%），最低温度下降 1°C。TACI 的发病率与 IS 模式一致，而对于 PACIs 和 POCIs，较长的危险期有更强的影响，而 LACI 则没有相关性。前一天最大温度每下降 1°C，致命性中风与非致命性中风的相对风险增加 15.5%（95%CI：6.1-25.4%）。
室外温度和相关气象参数与中风的发生和严重程度有关。温度影响的不同危险期以及与 LACI 无关可能解释了社区和住院患者研究中天气对中风发生的异质性影响。急救服务部门应该意识到，特定的天气条件更有可能导致更严重的中风呼叫。
