MRC Lifecourse Epidemiology Unit, University of Southampton, Southampton SO16 6YD, UK.
NIHR Southampton Biomedical Research Centre, University of Southampton and University Hospital Southampton NHS Foundation Trust, Tremona Road, Southampton, UK.
J Public Health (Oxf). 2020 Nov 23;42(4):e440-e448. doi: 10.1093/pubmed/fdz131.
We investigated whether the incidence of death following myocardial infarction (MI) varied by season and latitude in the Swedish population.
We studied deaths following MI from January 1987 to December 2009, using the Swedish National Cause of Death Register. County of residence was used to determine latitude and population density. An extension of Poisson regression was used to study the relationship between risk of death following MI with age, latitude, time (from 1987), population density and calendar days.
Over the study period, there was a secular decrease in the incidence of MI-related death. In men, MI-related death incidence increased by 1.3% [95% confidence interval (CI) = 1.1-1.5] per degree of latitude (northwards). In women, MI-related death incidence increased by 0.6% (95% CI = 0.4-0.9) per degree of latitude. There was seasonal variation in the risk of MI-related death with peak values in the late winter and a nadir in the summer months in both the north and the south of Sweden. Findings were similar with incident MI as the outcome.
The incidence of MI-related death varied markedly by season and latitude in Sweden, with summer months and more southerly latitude associated with lower rates than winter months and more northerly latitude.
我们研究了在瑞典人群中，心肌梗死（MI）后死亡的发生率是否随季节和纬度而变化。
我们使用瑞典国家死因登记处研究了 1987 年 1 月至 2009 年 12 月期间 MI 后的死亡情况。居住地的县用于确定纬度和人口密度。泊松回归的扩展用于研究 MI 后死亡风险与年龄、纬度、时间（1987 年以来）、人口密度和日历天数之间的关系。
在研究期间，MI 相关死亡的发生率呈下降趋势。在男性中，MI 相关死亡的发生率每增加一度纬度（向北）就增加 1.3%（95%置信区间 [CI]：1.1-1.5）。在女性中，MI 相关死亡的发生率每增加一度纬度就增加 0.6%（95%CI：0.4-0.9）。MI 相关死亡的风险存在季节性变化，在瑞典的北部和南部，冬季末达到峰值，夏季达到低谷。以新发 MI 为结局的研究结果相似。
在瑞典，MI 相关死亡的发生率随季节和纬度变化显著，夏季和较南的纬度与冬季和较北的纬度相比，死亡率较低。
