Department of General Medicine, Saiseikai Utsunomiya Hospital, Japan.
Department of Health Preservation, Yuri Kumiai General Hospital, Japan.
Intern Med. 2021 Sep 15;60(18):2933-2938. doi: 10.2169/internalmedicine.6146-20. Epub 2021 Mar 29.
Objective It has been established that stroke occurrence is influenced by seasonality. Stroke is divided into three subtypes: cerebral hemorrhage (CH), cerebral infarction (CI), and subarachnoid hemorrhage (SAH). The purpose of this paper was to analyze stroke events by subtype and month, in order to clarify the biggest factors that affect seasonal differences and thereby gain insight into stroke prevention. Methods Initial stroke events in the Akita Stroke Registry from 1991 to 2010 (58,684 cases; male 30,549, female 28,135) were classified by subtype and the month of onset, and correlations were estimated based on 115 healthy volunteers' monthly mean resting blood pressure (BP) at home and outdoor temperature measured by the Akita Meteorological Observatory in 2001. Results Systolic BP showed monthly variation in both morning and evening measurements. BP and outdoor temperature showed significant correlations with hemorrhagic stroke events by month (CH: r=0.87, r=-0.82; SAH: r=0.68, r=-0.82). Among the stroke subtypes, seasonal differences were the greatest in CH. Systolic BP was the most important factor for monthly and seasonal variation in stroke events. By comparing monthly BP variations with CH incidence throughout the year, we concluded that a decrease in home BP of 5 mmHg can reduce the risk of CH by 35%. Conclusion Our findings suggest that lowering BP would be the best strategy for CH prevention. Simple daily actions may be affected by cold stress. As physicians, we must strive to help patients lower their BP throughout the year not only with medication but with lifestyle guidance, especially in winter.
目的 已有研究证实，中风的发生受季节性影响。中风可分为三种亚型：脑出血（CH）、脑梗死（CI）和蛛网膜下腔出血（SAH）。本文旨在分析各亚型中风按月发病的情况，以明确影响季节性差异的最大因素，从而深入了解中风的预防。
方法 将 1991 年至 2010 年在秋田中风登记处（58684 例；男性 30549 例，女性 28135 例）的初始中风事件按亚型和发病月份分类，并基于 2001 年秋田气象观测站测量的 115 名健康志愿者的家庭月平均静息血压（BP）和室外温度进行相关性估计。
结果 晨测和晚测的收缩压均呈现出月度变化。BP 和室外温度与出血性中风事件按月发病情况具有显著相关性（CH：r=0.87，r=-0.82；SAH：r=0.68，r=-0.82）。在中风亚型中，CH 的季节性差异最大。收缩压是影响中风事件月度和季节性变化的最重要因素。通过比较全年每月 BP 变化与 CH 发生率，我们得出结论，家庭 BP 降低 5mmHg，可使 CH 风险降低 35%。
结论 我们的研究结果表明，降低血压可能是 CH 预防的最佳策略。日常简单行为可能会受到寒冷压力的影响。作为医生，我们不仅要通过药物治疗，还要通过生活方式指导，帮助患者全年控制血压，特别是在冬季。
