Background:Using a population-based stroke registry system, we evaluated the relationship between ambient temperature parameters and stroke incidence in a Japanese population.

Methods and Results:We analyzed data from the Takashima Stroke Registry, which records all stroke occurrences in Takashima City, Japan. The study period of 8,401 days was divided into quintiles of daily weather parameters, and the middle quintile was used as the reference category. Incidence rates (IR per 100,000 person-years) were calculated across the quintiles. Poisson regression analysis was used to calculate the effect of temperature parameters on stroke incidence. There were 2,405 first-ever strokes (1,294 men), including 1,625 ischemic, 545 cerebral hemorrhages, 213 subarachnoid hemorrhages, and 22 unclassified strokes. The stroke IR was higher in the middle quintile of average temperature, 357.3 (328.4–388.8), and for other parameters. After adjustment for age and sex, for all stroke, the incidence rate ratio (IRR) in the highest (Q5: IRR 0.81, 95% confidence interval (CI) 0.71–0.92) and the second-highest (Q4: IRR 0.80, 95% CI 0.71-0.91) quintile was lower than that in the middle quintile (Q3: Reference). Analogous results were observed for the minimum, maximum, and lag-days temperatures, also in the subtypes and across ≥65 years of age, also in females.

Conclusions:Higher temperatures, irrespective of the parameter (average, minimum, or maximum), had a protective effect against stroke occurrence in Japan.

背景：使用基于人群的卒中登记系统，我们评估了日本人群中环境温度参数与卒中发病率之间的关系。

方法和结果：我们分析了来自高岛中风登记处的数据，该登记处记录了日本高岛市的所有中风事件。将 8401 天的研究周期分为每日天气参数的五分位数，中间五分位数作为参考类别。计算了五分之一的发病率（每 100,000 人年的 IR）。泊松回归分析用于计算温度参数对卒中发病率的影响。有 2,405 例首次中风（1,294 名男性），包括 1,625 例缺血性中风、545 例脑出血、213 例蛛网膜下腔出血和 22 例未分类中风。中风 IR 在平均温度的中间五分位数中较高，357.3 (328.4-388.8) 和其他参数。调整年龄和性别后，所有卒中的发病率比（IRR）最高（Q5：IRR 0.81，95% 置信区间 (CI) 0.71-0.92) 和第二高 (Q4: IRR 0.80, 95% CI 0.71-0.91) 五分位数低于中间五分位数 (Q3: Reference)。在最低、最高和滞后日温度方面也观察到了类似的结果，在亚型和 65 岁以上的女性中也是如此。

结论：无论参数（平均值、最小值或最大值）如何，较高的温度都对日本中风的发生具有保护作用。