Background

To date, there have been relatively few studies of acute cardiovascular responses to controlled ozone inhalation, although a number of observational studies have reported significant positive associations between both ambient ozone levels and acute cardiovascular events and long-term ozone exposure and cardiovascular mortality.

Objectives

We hypothesized that short-term controlled exposure to low levels of ozone in filtered air would induce autonomic imbalance, repolarization abnormalities, arrhythmia, and vascular dysfunction.

Methods

This randomized crossover study of 87 healthy volunteers 55–70 years of age was conducted at three sites using a common protocol, from June 2012 to April 2015. Subjects were exposed for 3 h in random order to 0 ppb (filtered air), 70 ppb ozone, and 120 ppb ozone, alternating 15 min of moderate exercise with 15 min of rest. A suite of cardiovascular endpoints was measured the day before, the day of, and up to 22 h after each exposure. Mixed effect linear and logit models evaluated the impact of exposure to ozone on pre-specified primary and secondary outcomes. Site and time were included in the models.

Results

We found no significant effects of ozone exposure on any of the primary or secondary measures of autonomic function, repolarization, ST segment change, arrhythmia, or vascular function (systolic blood pressure and flow-mediated dilation).

Conclusions

In this multicenter study of older healthy women and men, there was no convincing evidence for acute effects of 3-h, relatively low-level ozone exposures on cardiovascular function. However, we cannot exclude the possibility of effects with higher ozone concentrations, more prolonged exposure, or in subjects with underlying cardiovascular disease. Further, we cannot exclude the possibility that exposure to ambient ozone and other pollutants in the days before the experimental exposures obscured or blunted cardiovascular biomarker response to the controlled ozone exposures.

中文翻译：

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心血管功能和臭氧暴露：老年受试者的多中心臭氧研究（MOSES）

背景

迄今为止，关于急性心血管对受控臭氧吸入的反应的研究相对较少，尽管许多观察性研究报告了环境臭氧水平与急性心血管事件以及长期臭氧暴露和心血管死亡率之间存在显着的正相关性。

目标

我们假设短期控制暴露于过滤空气中的低水平臭氧会导致植物神经失衡，复极异常，心律不齐和血管功能障碍。

方法

从2012年6月至2015年4月，采用通用方案在三个地点对87位55-70岁的健康志愿者进行了随机交叉研究。受试者随机暴露3 h，分别为0 ppb（过滤空气），70 ppb臭氧和120 ppb臭氧，进行15分钟的适度运动和15分钟的休息时间。在每次暴露的前一天，一天以及之后最多22小时内测量了一组心血管终点。混合效应线性模型和对数模型评估了臭氧暴露对预先指定的主要和次要结果的影响。模型中包括地点和时间。

结果

我们发现臭氧暴露对植物神经功能，复极，ST段改变，心律不齐或血管功能（收缩压和血流介导的扩张）的任何主要或次要指标均无显着影响。

结论

在这项针对老年健康男女的多中心研究中，没有令人信服的证据表明3小时相对较低水平的臭氧暴露对心血管功能有急性影响。但是，我们不能排除臭氧浓度更高，接触时间更长或对潜在的心血管疾病有影响的可能性。此外，我们不能排除在实验暴露前几天暴露于环境臭氧和其他污染物的可能性模糊或减弱了心血管生物标记物对受控臭氧暴露的反应的可能性。