Shigematsu K, Watanabe Y, Nakano H
Department of Neurology, National Hospital Organization, Minami Kyoto Hospital, Kyoto, Japan.
Department of Epidemiology for Community Health and Medicine, Kyoto Prefectural University of Medicine, Graduate School of Medical Science, Kyoto, Japan.
Acta Neurol Scand. 2015 Dec;132(6):423-9. doi: 10.1111/ane.12412. Epub 2015 Apr 9.
The aim of this study was to investigate the seasonal variation of the ratio of hemorrhagic stroke to ischemic stroke. The working hypothesis is that the ratio may vary among seasons.
A total of 13,788 patients registered in the Kyoto Stroke Registry from 1999 to 2009 were divided into 4 groups based on the season in which stroke developed. We calculated odds ratio (OR) for the incidence of stroke as a whole, cerebral infarction (CeI), cerebral hemorrhage (CH), and subarachnoid hemorrhage (SAH) in spring, autumn, and winter setting summer as a reference. Using a logistic regression, we evaluated the seasonal variation of ORs for CH/CeI and for SAH/CeI with adjustment for age, gender, and risk factors.
Incidence of CeI in autumn was lower than in summer (OR: 0.93; 0.87-0.98, P = 0.013). Incidence of CH was higher in spring (OR: 1.36; 1.23-1.49, P < 0.001), in autumn (OR: 1.16; 1.05-1.28, P = 0.004), and in winter (OR: 1.37; 1.25-1.51, P < 0.001) than in summer. Incidence of SAH was higher in spring (OR: 1.51; 1.28-1.79, P < 0.001) and in winter (OR: 1.44; 1.22-1.70, P < 0.001) than in summer. OR for CH/CeI in spring, autumn, and winter were 1.28 (1.13-1.45, P < 0.001), 1.26 (1.11-1.43, P < 0.001), and 1.35 (1.19-1.53, P < 0.001), respectively. ORs for SAH/CeI were 1.46 (1.19-1.79, P < 0.001), 1.34 (1.09-1.66, P = 0.007), and 1.50 (1.22-1.84, P < 0.001), respectively.
Seasonal variations differed among stroke subtypes. The OR for CH/CeI and for SAH/CeI was lower in summer and higher in the rest of seasons independent of age, gender, and risk factors.
本研究旨在调查出血性卒中与缺血性卒中比例的季节性变化。研究的假设是该比例可能随季节而变化。
将1999年至2009年在京都卒中登记处登记的13788例患者，根据卒中发生的季节分为4组。我们计算了以夏季为参照时，春季、秋季和冬季卒中整体、脑梗死（CeI）、脑出血（CH）和蛛网膜下腔出血（SAH）发病的比值比（OR）。通过逻辑回归，我们在对年龄、性别和危险因素进行校正后，评估了CH/CeI和SAH/CeI的OR的季节性变化。
秋季CeI的发病率低于夏季（OR：0.93；0.87 - 0.98，P = 0.013）。CH的发病率在春季（OR：1.36；1.23 - 1.49，P < 0.001）、秋季（OR：1.16；1.05 - 1.28，P = 0.004）和冬季（OR：1.37；1.25 - 1.51，P < 0.001）均高于夏季。SAH的发病率在春季（OR：1.51；1.28 - 1.79，P < 0.001）和冬季（OR：1.44；1.22 - 1.70，P < 0.001）高于夏季。春季、秋季和冬季CH/CeI的OR分别为1.28（1.13 - 1.45，P < 0.001）、1.26（1.11 - 1.43，P < 0.001）和1.35（1.19 - 1.53，P < 0.001）。SAH/CeI的OR分别为1.46（1.19 - 1.79，P < 0.001）、1.34（1.09 - 1.66，P = 0.007）和1.50（1.22 - 1.84，P < 0.001）。
不同卒中亚型的季节性变化有所不同。CH/CeI和SAH/CeI的OR在夏季较低，在其他季节较高，且不受年龄、性别和危险因素的影响。
