OBJECTIVES Real-world evidence on exposure to harmful and potentially harmful constituents (HPHCs) and on biological effects in cigarette smokers who switch to electronic nicotine delivery systems (ENDS) can inform the health effects of switching. METHODS This cross-sectional, observational study assessed adults who had smoked ≥10 cigarettes/day for ≥10 years, comparing 124 continuing cigarette smokers (Smokers) to 140 former smokers who switched to JUUL-brand ENDS exclusively for ≥6 months (Switchers). Assessments included biomarkers of exposure (BOEs) to select HPHCs, biomarkers of potential harm (BOPHs) related to smoking-related diseases, psychometric assessments of dependence on cigarettes and ENDS, respectively, and respiratory symptoms. Planned analyses compared geometric means, adjusted for demographic covariates; further analyses adjusted for additional lifestyle and smoking history covariates. RESULTS Nicotine levels were significantly higher in Switchers (median time switched=3 years), who were unusually heavy users of JUUL. All other BOEs, including NNAL and HPMA3 (primary endpoints), were significantly lower in Switchers than Smokers. Most BOPHs (sICAM-1 [primary], and e.g., white blood cell count, MCP1, HbA1c) were significantly lower in Switchers than Smokers; HDL was significantly higher. Switchers reported significantly lower dependence on JUUL than Smokers did on cigarettes, and respiratory symptom scores were significantly lower among Switchers than Smokers. CONCLUSIONS Compared to continuing smokers, smokers who switched to JUUL had substantially lower exposures to multiple HPHCs, favorable differences in markers of inflammation, endothelial function, oxidative stress, and cardiovascular risk, and less respiratory symptoms. These findings suggest that switching from cigarettes to JUUL likely reduces smokers' health risks. IMPLICATIONS Short-term confinement studies and randomized clinical trials demonstrate that adult smokers who switch completely to ENDS experience substantial reductions in exposure to many smoking-related toxicants. This study extends those findings to longer periods of switching to JUUL-brand ENDS (almost 3 years on average) under naturalistic use conditions in real-world settings, and also found that switching to JUUL resulted in favorable differences in BOPHs more proximally related to smoking-induced disease, as well as in respiratory symptoms. Smokers who switch to ENDS reduce their exposure to toxicants, likely reducing their disease risk.

中文翻译：

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比较转用 JUUL 的成年吸烟者与继续吸烟者：暴露、潜在危害和呼吸道症状的生物标志物。

目标 关于转用电子尼古丁输送系统 (ENDS) 的吸烟者接触有害和潜在有害成分 (HPHC) 以及生物效应的真实世界证据可以告知转用电子尼古丁输送系统 (ENDS) 的健康影响。方法 这项横断面观察性研究评估了每天吸烟 10 支以上且持续 10 年以上的成年人，比较了 124 名持续吸烟者（吸烟者）和 140 名转用 JUUL 品牌 ENDS 超过 6 个月的戒烟者（转换者） 。评估包括选择 HPHC 的暴露生物标志物 (BOE)、与吸烟相关疾病相关的潜在危害生物标志物 (BOPH)、对香烟和 ENDS 依赖的心理测量评估以及呼吸道症状。计划分析比较几何平均值，并根据人口统计协变量进行调整；进一步分析调整了额外的生活方式和吸烟史协变量。结果 转换者（中位转换时间 = 3 年）的尼古丁水平显着较高，他们是 JUUL 的大量使用者。所有其他 BOE，包括 NNAL 和 HPMA3（主要终点），切换者的 BOE 均显着低于吸烟者。大多数 BOPH（sICAM-1 [主要]，例如白细胞计数、MCP1、HbA1c）在转换者中显着低于吸烟者；HDL 显着升高。转换者对 JUUL 的依赖明显低于吸烟者对卷烟的依赖，转换者的呼吸道症状评分也显着低于吸烟者。结论 与持续吸烟者相比，改用 JUUL 的吸烟者对多种 HPHC 的暴露显着降低，炎症标志物、内皮功能、氧化应激和心血管风险存在良好差异，并且呼吸道症状较少。这些发现表明，从香烟转向 JUUL 可能会降低吸烟者的健康风险。短期限制研究和随机临床试验表明，完全改用电子尼古丁传送系统的成年吸烟者接触许多与吸烟相关的毒物的机会大大减少。这项研究将这些发现扩展到现实环境中自然使用条件下更长时间改用 JUUL 品牌 ENDS（平均近 3 年），并且还发现改用 JUUL 会导致与吸烟更密切相关的 BOPH 出现有利差异诱发的疾病，以及呼吸道症状。改用电子尼古丁传送系统的吸烟者减少了对有毒物质的接触，可能降低了他们患病的风险。