研究揭示了炎热天气是如何损害免疫系统的

A study that looked at how the immune system reacts to hot weather offers new insight into what's happening when the mercury rises.

Researchers found a link between hot weather and measures of the body's immune response, 包括某些血细胞的水平和炎症指标. It's a step toward eventually finding treatments that could help protect people from dangerously high temperatures, 哪些与心脏病发作率增加有关, 中风和其他心血管疾病.

的 研究, 该研究于周二在美国心脏协会的流行病学会议上发表, 预防, 生活方式和心脏代谢健康会议, is considered preliminary until full results are published in a peer-reviewed journal.

Previous studies had linked temperature and inflammation, said lead 研究er Dr. 丹尼尔·W. 里格斯, an epidemiologist and an assistant professor in the division of environmental medicine at the University of Louisville School of Medicine in Kentucky.

炎症, 哪些与心脏病风险有关, 这是身体对感染或损伤的反应吗. 不同类型的白细胞也是免疫反应的一部分. Some of those cells release proteins called cytokines, which regulate inflammation. 其他免疫细胞直接攻击细菌和病毒等入侵者.

Cytokines and immune cells can be measured as markers of how much the body has ramped up its defenses in response to a perceived threat.

Earlier studies of heat and inflammation had looked at just a few signals of how the body was responding, 里格斯说. He and his colleagues "wanted to get a fuller picture of what the relationship with higher temperatures and these markers could be."

研究小组研究了624人的血液样本 绿心计划, which is studying how planting greenery in a Louisville neighborhood might improve air quality and reduce heart disease.

研究参与者的年龄从20岁到70岁不等，平均年龄为50岁. 大约77%是白人，18%是黑人，59%是女性. 在2018年和2019年的夏天，每个人都提供了一份血液样本.

Researchers measured 11 types of cytokines and nine types of immune cells in each sample. 的 weather on the day of each blood draw was assessed using the Universal 的rmal Climate Index, 测量温度, 湿度和风速影响人体的舒适度. 测量期间的平均24小时UTCI是78华氏度.

然后将血液测量值与天气读数相匹配, and the results were adjusted for differences in demographic factors such as sex, 年龄, 种族与教育. 研究结果还根据体重指数(衡量肥胖的一种指标)进行了调整。, air pollution and whether the person smoked or was taking anti-inflammatory medication.

的 results showed a link between hot weather and increased levels of several cytokines. 其中之一, tnf, is "one of the major inflammatory markers and plays an important role in cardiovascular disease,里格斯说.

同时, hot weather was associated with higher levels of some classes of white blood cells known as monocytes, which could be a sign that heat is causing inflammation or prompting an immune response, 里格斯说.

高温还与另一类单核细胞水平降低有关, 被称为非经典, 这会降低炎症. And heat also was linked to lower levels of infection-fighting and blood-cleansing white blood cell known as B cells. Lower levels of those cells could mean someone is more susceptible to infection, 里格斯说.

He was surprised to see so many types of cells change with the short-term exposure to hot weather. 这项研究并没有研究是什么导致了这种情况, 但里格斯说，热适应可能会导致热休克蛋白的增加, 哪些已知参与免疫和炎症反应.

我认为这是一项重要的研究. 朱迪斯·里奇曼, chair of the department of chronic disease epidemiology at Yale School of Public Health in New Haven, 康涅狄格. She has done 研究 on how temperature affects stroke rates but was not involved in the new work.

A lot of the prior 研究 has looked at whether heat waves lead to more hospitalizations or deaths, 她说. “这项研究的价值在于他们真的在试图理解, 在身体层面, 可能导致这种风险增加的机制."

这项研究只考察了一个社区, 她说, 因此，这些发现需要在更广泛的范围内进行复制. 在这样的研究中, it's not clear how much people are actually being exposed to the outdoor heat; people could be staying inside in air conditioning.

但总的来说，利特曼说，这项研究“开辟了一个新的研究领域”." Understanding heat's effects on the body will gain importance as the climate changes, and if 研究ers can start to understand how aspects of the environment affect health, “也许我们还可以想出新的方法来降低心血管疾病的风险."

Climate change is expected to increase the number of extreme heat events, 里格斯说. "Our future 研究 will focus on the long-term effects of exposure to extreme heat events on immune responses and inflammation, 以及这与心血管疾病的发展有何关系."

作为路易斯维尔绿色之心项目的一部分, 里格斯说, "we're going to look into whether actually tree-planting could mitigate the effects on your immune system and inflammation.其他正在进行的研究包括收集更多的血液样本. “这项研究的主要局限性是它只有一个沙巴足球体育平台点,他说, 更多的样本将显示这些发现是否会持续.

“你对其机制了解得越多, 你就越能明确地开展预防和治疗工作,他说.