Physiological effects following acute exposure to electronic cigarettes
| Reference | Study population | Study groups | Summary of results |
|---|---|---|---|
| Vansickel et al20 | 32 smokers e-cig naive; two cigs (10 puffs) each type | Own brand cig | Increased heart rate, plasma nicotine & CO |
| 18 mg e-cig | No measurable increase in heart rate, plasma nicotine or CO level | ||
| 16 mg e-cig | |||
| Sham cig | |||
| Vardavas et al21 | 30 healthy adult smokers (e-cig status unknown); Used e-cig for 5 minutes | Nicotine-containing e-cig | Decrease in FeNO; Increase in respiratory impedance and respiratory flow resistance (similar to cigarette use) |
| No-cartridge e-cig | Control | ||
| Flouris et al 22 24 | 15 smokers # puffs adjusted for smoking history | Active cig | Increase in WBC, lymphocyte, granulocyte counts; cotinine increased; FEV1/FVC decreased |
| Active e-cig | CBC indices unchanged; cotinine increased; FEV1/FVC unchanged | ||
| Passive e-cig | |||
| Passive cig | Increase in WBC, lymphocyte, granulocyte counts; cotinine increased; FEV1/FVC unchanged | ||
| Chorti et al 23 | 15 cigarette smokers; used one e-cig | Passive smoking | Increased CO and cotinine |
| Smoke 2 usual brand cigs | Decreased FEV1, FEV1/FVC, & FeNO; increased cotinine and CO | ||
| Active e-cig | Lung function unchanged; cotinine increased | ||
| Passive e-cig | Reduced FEV1/FVC; increased cotinine | ||
| Farsalinos et al25 | 22 ex-cigarette e-cig users | Baseline cardiac echo, repeat study after one cig or e-cig | No change in cardiac echo parameters |
| 20 current cigarette users | Measurable decrease in LV function | ||
| Tzatzarakis, et al26 | 10 smokers Brief active e-cig session | Active cig | Increased interleukins and epidermal growth factor |
| Active e-cig | No increase in assessed inflammatory markers | ||
| 10 never-smokers; 1 h exposure | Passive cig | Increased tumour necrosis factor alpha | |
| Passive e-cig | No increase in assessed inflammatory markers |
CBC, complete blood count; CO, carbon monoxide; e-cig, electronic cigarette; FeNO, fractional exhaled nitric oxide, FEV1, forced expiratory volume in 1 s; FVC, forced vital capacity; LV, left ventricle; WBC, white blood count.