Table 3.
Geometric Means and 95% Confidence Intervals of Levels of Toxicant and Carcinogen Metabolites in the Urine of e-Cigarette Users and Cigarette Smokers by Study, Adjusted for Age and Gender
| Metabolite | e-Cigarettes | Cigarette smokers | |||||
|---|---|---|---|---|---|---|---|
| e-Cigarette users, N = 28 | Carmella et al. 15 (N = 17) | Hatsukami et al. 17 (N = 165) | Zarth et al. 14 (N = 40) | ||||
| Geometric mean (95% CI) | Geometric mean (95% CI) | p valuea | Geometric mean (95% CI) | p valuea | Geometric mean (95% CI) | p valuea | |
| 1-HOP (pmol/ml) | 0.38 (0.26–0.55) | 0.88 (0.55–1.41) | .013 | 0.97 (0.80–1.17) | <.0001 | Not analyzed | |
| Total NNAL (pmol/ml) | 0.02 (0.02–0.03) | 1.48 (0.90–2.43) | <.0001 | 1.21 (0.99–1.47) | <.0001 | Not analyzed | |
| 3-HPMA (pmol/ml) | 1,100 (766–1,590) | 5,800 (3,730–9,030) | <.0001 | 4,040 (3,380–4,830) | <.0001 | 6,070 (4,580–8,050) | <.0001 |
| 2-HPMA (pmol/ml) | 141 (80–252) | Not analyzed | Not analyzed | 399 (255–626) | .006 | ||
| HMPMA (pmol/ml) | 705 (456–1,090) | 4,990 (2,930–8,490) | <.0001 | Not analyzed | Not analyzed | ||
| SPMA (pmol/ml) | 0.29 (0.18–0.46) | 1.11 (0.61–2.08) | 0.001 | 2.85 (2.24–3.63) | <.0001 | Not analyzed | |
| Nicotine (ng/ml) | 869 (604–1,250) | Not analyzed | 1,380 (1190–1,600) | .035 | 1,270 (834–1,710) | .182 | |
| Cotinine (ng/ml) | 1,880 (1,420–2,480) | Not analyzed | 3,930 (3,500–4,400) | <.0001 | 1,930 (1,530–2,440) | .981 | |
1-HOP = 1-hydroxypyrene; 2-HPMA = 2-hydroxypropylmercapturic acid; 3-HPMA = 3-hydroxypropylmercapturic acid; CI = confidence interval; HMPMA = 3-hydroxy-1-methylpropylmercapturic acid; NNAL = 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol; SPMA = S-phenylmercapturic acid.
aCompared to e-cigarette users, adjusted for age and gender.