Table 2.
Urinary biomarkersa at Wave 1 in association with functionally important respiratory symptoms at Wave 2
| Urinary biomarkers | Nonusers (n = 2849) | Exclusive E-cigarette users (n = 222) | Poly E-cigarette/tobacco users (n = 1543) | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Respiratory symptoms | Respiratory symptoms | Respiratory symptoms | |||||||
| No (2008) | Yes (n = 829) | Adjusted p-valueb | No (n = 153) | Yes (n = 69) | Adjusted p-valueb | No (n = 756) | Yes (n = 781) | Adjusted p-valueb | |
| Geo mean (95% CI) | Geo mean (95% CI) | Geo mean (95% CI) | Geo mean (95% CI) | Geo mean (95% CI) | Geo mean (95% CI) | ||||
| Urinary nicotine metabolites (ng/mg creatinine) | |||||||||
| TNE2c(nmol/mg creatinine) | 0.01 (0.01-0.01) | 0.04 (0.03–0.06)1 | <.0001 | 2.3 (1.2–4.6) | 5.9 (2.3–14.7)2 | 0.017 | 12.5 (9.7–16.2) | 31.1 (26.9–36.0)3 | <.0001 |
| Cotinine | 0.8 (0.6–0.9) | 2.7 (2–3.7)1 | <.0001 | 148.1 (72.9–301.0) | 341.3 (135.3–861.0)2 | 0.0245 | 817.6 (626.1–1067.5) | 2031.4 (1769.0–2332.6)3 | <.0001 |
| TSNAs (pg/mg creatinine) | |||||||||
| NNAL | 1.4 (1.2–1.6) | 3.1 (2.4–3.9)1 | <.0001 | 4.4 (3.5–5.6) | 10.7 (6.5–17.5)2 | 0.0043 | 98.9 (79.7–122.7) | 199.6 (176.7–225.4)3 | 0.0001 |
| N′-Nitrosonornicotine | 2.2 (2.0–2.3) | 2.8 (2.5–3)1 | 0.0053 | 3.3 (2.8–3.8) | 3.6 (2.7–4.8)1 | 0.8939 | 8.0 (6.9–9.4) | 10.2 (9.4–11.2)2 | 0.4374 |
| Heavy metals (ng/mg creatinine) | |||||||||
| Cadmium (UCD) | 0.2 (0.1–0.2) | 0.2 (0.2-0.2)1 | 0.2931 | 0.2 (0.1–0.2) | 0.3 (0.2–0.4)2 | 0.0110 | 0.2 (0.1–0.2) | 0.2 (0.2–0.3)2 | 0.8579 |
| Lead (UPB) | 0.4 (0.3–0.4) | 0.4 (0.3–0.4)1 | 0.5484 | 0.4 (0.3–0.4) | 0.5 (0.4–0.7)2 | 0.0885 | 0.4 (0.4-0.4) | 0.5 (0.4–0.5)2 | 0.5526 |
| PAHs (ng/mg creatinine) | |||||||||
| 1-Naphthol or 1-hydroxynaphthalene (1-NAP) | 1.5 (1.4–1.7) | 2.2 (1.8–2.5)1 | 0.0359 | 1.4 (1–1.9) | 2.5 (1.7–3.6)1 | 0.1526 | 6.9 (5.9–8) | 11.4 (9.9–13)2 | 0.0028 |
| 3-Hydroxyfluorene (3-FLU) | 0.07 (0.07–0.08) | 0.1 (0.09–0.11)1 | 0.0058 | 0.06 (0.05–0.07) | 0.1 (0.08–0.13)1 | 0.0066 | 0.37 (0.33–0.41) | 0.55 (0.5–0.6)2 | 0.0002 |
| VOCs (ng/mg creatinine) | |||||||||
| CEMA) (Acrolein) | 99 (94.4–103.8) | 114.3 (103.9–125.9)1 | 0.0268 | 98.9 (90–108.8) | 123.6(102.3–149.2)1 | 0.0733 | 197.1 (180.4–215.4) | 280 (261.7–299.5)2 | <.0001 |
| CYMA (acrylonitrile) | 1.6 (1.5–1.8) | 3.5 (3–4.1)1 | <.0001 | 3.4 (2.6–4.4) | 7.3 (4.6–11.6)2 | 0.0087 | 58.1 (47.7–70.7) | 122.5 (107.7–139.3)3 | <.0001 |
Geo Mean: geometric mean of concentration.
aAll analyses applied urinary sample weight, 100 replicated weights, and the balanced repeated replication method with Fay’s adjustment = 0.3 to account for the PATH Study’s complex design.
bSeparate analyses were performed for three exclusive e-cigarette user groups (no use of e-cigarette and tobacco product, exclusive e-cigarette use, and use of e-cigarettes and 1+ type of tobacco product) based on the self-report. Multivariable general linear regressions were conducted to examine the relationship between biomarker concentration levels at Wave 1 (outcome variable, log-transformed, and creatinine corrected) and respiratory symptoms at Wave 2, adjusted by baseline sociodemographics (sex, age, race/ethnicity, and education), self-reported exposure to SHS, past 12-month use of marijuana, and lung or respiratory disease. Bold indicates significance at .005 with adjustment for multiple comparisons using the Bonferroni method.
cTNE2: The molar sum of the imputed values of cotinine, and trans-3′-hydroxycotinine, urine.
1,2,3Multivariable general linear regressions were conducted to compare biomarker concentration levels (dependent variables) by e-cigarette use status among subjects with respiratory symptoms. E-cigarette user groups that were significantly different in pairwise contrasts are denoted by nonshared superscript numbers. The analysis was adjusted by baseline sociodemographics (sex, age, race/ethnicity, and education), self-reported exposure to SHS, past 12-month use of marijuana, and lung or respiratory disease.