Lin Che-Wei, Chen Po-Wei, Liu Wei-Min, Hsu Jin-Yi, Huang Yu-Lun, Cheng Yu, Liu An-Bang
Department of Biomedical Engineering, College of Engineering, National Cheng Kung University, Tainan 701401, Taiwan.
Medical Device Innovation Center, National Cheng Kung University, Tainan 704302, Taiwan.
J Clin Med. 2021 Oct 28;10(21):5041. doi: 10.3390/jcm10215041.
The associations between ambient temperatures and stroke are still uncertain, although they have been widely studied. Furthermore, the impact of latitudes or climate zones on these associations is still controversial. The Tropic of Cancer passes through the middle of Taiwan and divides it into subtropical and tropical areas. Therefore, the Taiwan National Health Insurance Database can be used to study the influence of latitudes on the association between ambient temperature and stroke events.
In this study, we retrieved daily stroke events from 2010 to 2015 in the New Taipei and Taipei Cities (the subtropical areas) and Kaohsiung City (the tropical area) from the National Health Insurance Research Database. Overall, 70,338 and 125,163 stroke events, including ischemic stroke and intracerebral hemorrhage, in Kaohsiung City and the Taipei Area were retrieved from the database, respectively. We also collected daily mean temperatures from the Taipei and Kaohsiung weather stations during the same period. The data were decomposed by ensemble empirical mode decomposition (EEMD) into several intrinsic mode functions (IMFs). There were consistent 6-period IMFs with intervals around 360 days in most decomposed data. Spearman's rank correlation test showed moderate-to-strong correlations between the relevant IMFs of daily temperatures and events of stroke in both areas, which were higher in the northern area compared with those in the southern area.
EEMD is a useful tool to demonstrate the regularity of stroke events and their associations with dynamic changes of the ambient temperature. Our results clearly demonstrate the temporal association between the ambient temperature and daily events of ischemic stroke and intracranial hemorrhage. It will contribute to planning a healthcare system for stroke seasonally. Further well-designed prospective studies are needed to elucidate the meaning of these associations.
尽管环境温度与中风之间的关联已得到广泛研究，但其关系仍不明确。此外，纬度或气候带对这些关联的影响仍存在争议。北回归线穿过台湾中部，将其分为亚热带和热带地区。因此，台湾全民健康保险数据库可用于研究纬度对环境温度与中风事件之间关联的影响。
在本研究中，我们从全民健康保险研究数据库中检索了2010年至2015年新北市和台北市（亚热带地区）以及高雄市（热带地区）的每日中风事件。总体而言，分别从数据库中检索到高雄市和台北地区70338例和125163例中风事件，包括缺血性中风和脑出血。我们还收集了同一时期台北和高雄气象站的日平均温度。数据通过总体经验模态分解（EEMD）分解为几个本征模态函数（IMF）。在大多数分解数据中，存在一致的6周期IMF，间隔约为360天。Spearman等级相关检验显示，两个地区日温度的相关IMF与中风事件之间存在中度至强相关性，北部地区的相关性高于南部地区。
EEMD是一种有用的工具，可用于证明中风事件的规律性及其与环境温度动态变化的关联。我们的结果清楚地证明了环境温度与缺血性中风和颅内出血每日事件之间的时间关联。这将有助于季节性地规划中风医疗保健系统。需要进一步设计良好的前瞻性研究来阐明这些关联的意义。
