AHJ：中海拔地区睡眠或降心源性猝死风险

　　美国一项研究表明，对于34岁以上、伴冠脉疾病病史和/或既往心肌梗死并且未习惯高海拔体力活动的男性，高海拔锻炼之前于中海拔睡眠可能降低心源性猝死（SCD）风险。论文5月13日在线发表于《美国心脏杂志》（American Heart Journal）。

　　此项回顾性队列研究共纳入559例高山活动期间死亡病例。通过既往调查问卷获取患者基线人口统计学、心血管共病、吸烟史、SCD家族史、睡眠海拔、年度登山频率和SCD当日体力活动。

　　结果显示，共有301例（79%）死者的数据可用于分析。心源性猝死大部分发生在中午（29%）；发生SCD的平均高度为1710 ± 501米。将睡眠海拔划分为四分位（<700 m，700-999 m，1000-1299 m和>1299 m）时，将海拔700米以下与1299米以上睡眠相比，高海拔首日发生SCD的比值比为5.7。

与心源性相关的拓展阅读：

• Heart：海产衍生n-3脂肪酸或降心源性死亡风险
• JACC：绝经后女性发生心源性猝死的相关危险因素
• Heart：冠脉疾病所致心源性猝死前常见心脏症状
• JAMA：心肌纤维化是扩张型心肌病患者发生心源性猝死的独立预测因素 更多信息请点击：有关心源性更多资讯

Sleeping altitude and sudden cardiac death
Background
Mountain activities characterized by strenuous exercise in a hypoxic setting place unique demands on the body. The mortality rate associated with mountain activities is high, with sudden cardiac death (SCD) representing the most frequent of all nontraumatic deaths. We evaluated the possible effect of acclimatization in reduction of SCD during high-altitude sojourns.
Methods
This was a retrospective cohort study involving all deaths (N = 559) that occurred during mountain activities in Austria from 1985 through 1993. Baseline patient demographics, cardiovascular comorbidities, smoking history, family history of SCD, sleeping altitude, annual mountaineering frequency, and physical activity on the day of SCD were included in a questionnaire previously used in a pilot study.
Results
Data from 301 of 599 individuals without prespecified exclusions were available for analysis (79% of eligible cohort). Sudden cardiac deaths happened mostly around noon (29%), and mean altitude at which SCDs occurred was 1,710 ± 501 m. When sleeping altitude was divided into quartiles (<700 m, 700-999 m, 1,000-1,299 m, and >1,299 m), the odds ratio for SCD on the first day at altitude when sleeping below 700 m was 5.7 (95% CI 2.8-11.6) as compared with sleeping above 1,299 m.
Conclusion
For males >34 years, those with history of coronary artery disease and/or prior infarction, and those unaccustomed to physical activity at altitude, sleeping at moderate altitude before exercising at altitude may reduce the risk of SCD.