Table 3. Urinary Biomarkers Among Exclusive e-Cigarette Users at Wave 1a.
| Biomarkers | No use at wave 2 (n = 44) | Cigarette only at wave 2 (n = 14) | e-Cigarette only at wave 2 (n = 121) | Dual use at wave 2 (n = 31) | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Geometric mean (95% CI) | P valueb | Adj. P valueb | Geometric mean (95% CI) | P valueb | Adj. P valueb | Geometric mean (95% CI) | P valueb | Adj. P valueb | Geometric mean (95% CI) | P valueb | Adj. P valueb | |||||
| Wave 1 | Wave 2 | Wave 1 | Wave 2 | Wave 1 | Wave 2 | Wave 1 | Wave 2 | |||||||||
| Urinary nicotine metabolites, ng/mg creatinine | ||||||||||||||||
| TNE2, nmol/mg creatininec | 0.27 (0.09- 0.79) | 0.04 (0.02-0.12) | <.001d | .38 | 7.23 (1.32-39.74) | 30.59 (18.97-49.35) | .05 | <.001d | 11.38 (5.89-21.96) | 7.46 (3.35-16.62) | .03 | .98 | 17.97 (11.32-28.52) | 46.68 (34.79-62.63) | <.001d | <.001d |
| Cotinine | 15.9 (5.1-49.7) | 2.4 (0.8-6.8) | <.001d | .28 | 501.9 (84.2-2991.3) | 1941.7 (1305-2889.1) | .08 | <.001d | 726.7 (359.8-1467.7) | 469.5 (200.2-1101) | .02 | .85 | 971.6 (591.9-1594.9) | 2568.6 (1815.7-3633.9) | <.001d | .001d |
| TSNAs, pg/mg creatinine | ||||||||||||||||
| NNAL | 4.6 (2.4-8.6) | 3.0 (1.6-5.4) | .07 | .69 | 32.7 (10.1-105.7) | 152.6 (78.8-295.2) | .01 | <.001d | 5.9 (4.1-8.3) | 4.2 (3.1-5.6) | .04 | .58 | 14.5 (7.7-27.2) | 62.0 (26.1-147.3) | <.001d | <.001d |
| NNN | 2.2 (1.6-3) | 1.7 (1.3-2.1) | .126 | .31 | 6.0 (2.5-14.7) | 8.6 (3.9-18.9) | .70 | <.001d | 4.2 (3.5-5.2) | 4.4 (3.4-5.7) | .83 | .93 | 3.6 (2.6-5.1) | 5.1 (3.4-7.9) | .16 | .17 |
| Heavy metals, ng/mg creatinine | ||||||||||||||||
| Cadmium | 0.12 (0.08-0.18) | 0.14 (0.1-0.18) | .31 | .77 | 0.24 (0.12-0.48) | 0.27 (0.14-0.53) | .20 | .01 | 0.24 (0.2-0.3) | 0.25 (0.21-0.3) | .75 | .72 | 0.17 (0.12-0.25) | 0.17 (0.13-0.23) | .99 | .12 |
| Lead | 0.36 (0.26-0.51) | 0.36 (0.28-0.47) | .98 | .67 | 0.59 (0.34-1.05) | 0.45 (0.26-0.78) | .06 | <.001d | 0.46 (0.39-0.55) | 0.4 (0.4-0.5) | .08 | .94 | 0.38 (0.29-0.49) | 0.4 (0.32-0.49) | .61 | .49 |
| PAHs, ng/mg creatinine | ||||||||||||||||
| 2-NAP | 5.6 (4.4-7.2) | 4.6 (3.5-6.2) | .26 | .96 | 8.5 (5.9-12.2) | 13.2 (9.6-18.2) | .02 | <.001d | 5.5 (4.7-6.5) | 5.6 (4.8-6.6) | .83 | .15 | 4.9 (3.7-6.5) | 6.5 (4.4-9.7) | .21 | .01 |
| 3-FLU | 0.07 (0.05-0.09) | 0.06 (0.04-0.08) | .69 | .20 | 0.11 (0.06-0.22) | 0.48 (0.33-0.69) | .00 | .05 | 0.09 (0.07-0.11) | 0.09 (0.07-0.11) | .57 | .67 | 0.09 (0.06-0.14) | 0.25 (0.15-0.41) | <.001d | <.001d |
| 1-PYR | 0.1 (0.1-0.2) | 0.1 (0.1-0.1) | .10 | .05 | 0.2 (0.1-0.3) | 0.3 (0.2-0.4) | .04 | .91 | 0.2 (0.1-0.2) | 0.2 (0.1-0.2) | .48 | .82 | 0.1 (0.1-0.2) | 0.2 (0.1-0.3) | .09 | .002 |
| VOCs, ng/mg creatinine | ||||||||||||||||
| AAMA | 56.3 (45.8-69.3) | 46.3 (39.1-54.7) | .06 | .08 | 84 (57.7-122.4) | 126.7 (93.5-171.9) | <.001d | <.001d | 62.9 (53.2-74.3) | 57.1 (47.9-68.1) | .20 | .63 | 54.9 (43.6-69) | 107.4 (82.1-140.7) | <.001d | <.001d |
| CEMA | 100.2 (81.9-122.5) | 90.5 (77-106.4) | .203 | .22 | 159.6 (116-219.4) | 257.7 (183.3-362.3) | .01 | .57 | 106.1 (92.4-121.9) | 100.0 (85.2-117.4) | .51 | .13 | 111.5 (84.9-146.6) | 203.8 (164.8-252.1) | <.001d | .02 |
| CYMA | 3.6 (2.0-6.5) | 2.1 (1.3-3.5) | .04 | .18 | 17.3 (5.4-54.8) | 125.9 (61.8-256.6) | <.001d | <.001d | 4.2 (3.1-5.8) | 3.2 (2.4-4.5) | .06 | .70 | 10.3 (5.4-19.6) | 43.3 (18.8-99.7) | <.001d | <.001d |
Abbreviations: 1-PYR, 1-hydroxypyrene; 2-NAP, 2-naphthol or 2-hydroxynaphthalene; 3-FLU, 3-hydroxyfluorene; AAMA, N-acetyl-S-(2-carbamoylethyl)-L-cysteine (acrylamide); Adj, adjusted; CEMA, N-acetyl-S-(2-carboxyethyl)-L-cysteine (acrolein); CYMA, N-acetyl-S-(2-cyanoethyl)-L-cysteine (acrylonitrile); NNAL, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol; NNN, N'-nitrosonornicotine; PAH, polycyclic aromatic hydrocarbon; TNE2, nicotine equivalence; TSNA, tobacco-specific nitrosamine; VOC, volatile organic compound.
All analyses applied urinary sample weight, 100 replicated weights, and the balanced repeated replication method with Fay adjustment of 0.3 to account for the Population Assessment of Tobacco and Health Study’s complex design.
P value was generated from univariate regression analysis to compare within-participant change of log (biomarkers of exposure/creatinine). Adjusted P value was generated from multivariable linear regressions, adjusted by demographic covariates (age, sex, race and ethnicity, and education).
Refers to the molar sum of the imputed values of cotinine and trans-3′-hydroxycotinine in urine.
Significant at P < .0042 with adjustment for multiple comparisons using the Bonferroni method (0.05/12 = .0042).