Faculty of Public Health and Policy, London School of Hygiene and Tropical Medicine, London, UK.
Center for Clinical Research and Prevention, Bispebjerg-Frederiksberg University Hospital, Capital Region of Denmark, Denmark; Danish Heart Foundation, Copenhagen, Denmark; University of Copenhagen, Faculty of Health and Medical Science, Denmark.
Prev Med. 2019 Oct;127:105770. doi: 10.1016/j.ypmed.2019.105770. Epub 2019 Jul 22.
Smoking is responsible for substantial cardiovascular morbidity and mortality. Electronic cigarettes have been advocated as a means to reduce this disease burden; by reducing exposure to harmful substances in smokers who are unable to quit. Concerns have been raised however, about cardiovascular effects of their use, with inhalants containing carbonyls and fine particulate matter. We systematically reviewed experimental studies of in vitro, animal, and human cardiovascular effects associated with electronic cigarette use.
A literature search was conducted using Ovid MEDLINE & Embase databases, identifying experimental studies investigating cardiovascular effects of electronic cigarette use. Subsequently, Cochrane Risk of Bias tools were used to assess study quality. Any differences in outcomes by conflict of interest and risk of bias status were sought.
38 studies were included, investigating animals (n=6), humans (n=24) and human cardiovascular cells in vitro (n=8). 74.3% of studies found potentially harmful effects. Increased sympathetic nerve activity was observed in human studies, whilst platelet haemostatic processes, reactive oxygen species production and endothelial dysfunction were reported across all study types. Studies with conflicts of interest or median-high risk of bias were less likely to identify potentially harmful effects (p=0.0007, p=0.04 respectively).
Most studies suggest potential for cardiovascular harm from electronic cigarette use, through mechanisms that increase risk of thrombosis and atherosclerosis. Notably, studies with conflicts of interest are significantly less likely to identify concerning cardiovascular effects. Included studies examine healthy, adult participants, limiting generalisation to potential high-risk groups including individuals with established cardiovascular disease or young, non-smokers.
吸烟是导致大量心血管疾病发病率和死亡率的主要原因。电子烟被提倡作为一种减少这种疾病负担的方法，通过减少无法戒烟的吸烟者接触有害物质。然而，人们对它们的使用对心血管的影响表示担忧，因为吸入物中含有羰基化合物和细颗粒物。我们系统地回顾了与电子烟使用相关的体外、动物和人体心血管效应的实验研究。
使用 Ovid MEDLINE 和 Embase 数据库进行文献检索，确定了调查电子烟使用对心血管影响的实验研究。随后，使用 Cochrane 偏倚风险工具评估研究质量。寻求了利益冲突和偏倚风险状况对结果的任何差异。
纳入了 38 项研究，涉及动物（n=6）、人类（n=24）和体外人类心血管细胞（n=8）。74.3%的研究发现了潜在的有害影响。人类研究中观察到交感神经活性增加，而所有研究类型均报告了血小板止血过程、活性氧产生和内皮功能障碍。有利益冲突或中高度偏倚风险的研究不太可能发现潜在的有害影响（p=0.0007，p=0.04）。
大多数研究表明电子烟使用可能对心血管有害，通过增加血栓形成和动脉粥样硬化风险的机制。值得注意的是，有利益冲突的研究明显不太可能发现令人担忧的心血管影响。纳入的研究检查了健康的成年参与者，将潜在的高风险人群（包括有既定心血管疾病或年轻非吸烟者）的一般化限制在这些研究范围内。
