Bright outdoor light at night may increase stroke risk

夜间过度暴露在明亮的户外灯光下可能会增加中风的风险, new research suggests.

The study involved more than 28,000 people living in a large city in China. 研究人员发现，夜间暴露在最高水平的室外人造光下的人患脑血管疾病的风险增加了43%, as compared to those with the lowest levels of exposure. 脑血管疾病包括中风和其他影响大脑血液流动的疾病.

Previous studies have linked increased exposure to bright, artificial light to the development of cardiovascular disease, which are conditions related to blood flow in arteries. 研究人员表示，他们的研究是首次探索夜间光线与大脑健康之间关系的研究之一.

“我们的研究表明，夜间过多暴露在室外人造光下可能是患脑血管疾病的一个危险因素," study co-author Dr. Jianbing Wang said in a news release. 王是儿童医院公共卫生和内分泌科的研究员, 浙江大学医学院、国家儿童健康临床研究中心, China. People, especially those living in urban areas, should consider reducing that exposure to protect themselves, he said.

这项研究周一发表在美国心脏协会期刊《线上电子游戏飞禽走兽》上.

该研究的作者说，世界上大约80%的人口生活在光污染的环境中. 夜间持续暴露在人造光下会抑制褪黑激素的产生, a hormone that promotes sleep. People with poor sleep, compared to good sleepers, are more likely to experience worse cardiovascular health over time, the researchers said.

这项研究涉及28302名生活在宁波的成年人，宁波是一个拥有8个以上人口的工业港口城市.2 million people on China's east coast. Almost 60% of the participants were women, and the average age was 62. 被排除在研究之外的是那些夜间暴露在户外光线下程度极高的人, 先前被诊断患有脑血管疾病的人以及在入组后一年内发病的人.

The analysis and follow-ups were conducted from 2015 to 2021. 通过绘制光污染地图的卫星图像评估住宅室外夜间灯光暴露情况. 中风病例由医院医疗记录和死亡证明证实.

Among the study participants, 1,278 people developed cerebrovascular disease, including 777 cases of ischemic stroke, the most common type of stroke, where a clot blocks blood flow to the brain.

该研究还研究了空气污染水平，发现其可能的影响与光照无关.

人们暴露在与汽油燃烧有关的最高水平的空气污染中, oil, 与接触最低水平的参与者相比，柴油燃料或木材患脑血管疾病的风险增加了41%.

暴露在由灰尘或烟雾引起的最高水平空气污染中的人患脑血管疾病的风险比暴露在最低水平空气污染中的人高50%.

还有那些暴露在机动车和发电厂排放物中氮氧化物含量最高的人, 与接触最少的人相比，患脑血管疾病的风险高31%.

“尽管在减少吸烟等传统心血管风险因素方面取得了重大进展, obesity and Type 2 diabetes, 在我们减少全球心血管疾病负担的努力中，考虑环境因素是很重要的," Wang said.

The population studied was from one city, so the findings may not apply to people in other communities, the authors said. 其他限制包括缺乏室内照明产品或遮阳措施(如遮光窗帘)的数据. Also, satellite-based products rarely capture blue light sources, 是什么导致了夜间户外光线与脑血管疾病之间的关联被低估.

“我们需要制定更有效的政策和预防战略，以减少光和空气污染等环境因素造成的疾病负担, particularly for people living in the most densely populated, polluted areas around the world," Wang said.