Table I.
Distributions of cigarette smoking and urinary biomarkers of tobacco smoke constituents among current smokers who developed lung cancer (cases) and those who remained cancer-free (controls), The Shanghai Cohort Study 1986–2007
| Controls (n = 392) | Cases (n = 343) | Two-sided Pa | ||
| Cigarette smoking | Arithmetic mean (95% CI) | |||
| No. of cigarettes per day | 15.3 (14.2–14.0) | 18.9 (17.7–20.0) | <0.001 | |
| No. of years of smoking | 30.8 (29.8–31.9) | 34.4 (33.3–35.4) | <0.001 | |
| No. of pack years of smoking | 24.4 (22.1–26.6) | 33.0 (30.8–35.3) | <0.001 | |
| Urinary biomarkers | Smoke constituents | Geometric mean (95% CI) | ||
| Total cotinine (nmol/mg Cr)b | Nicotine | 7.10 (6.14–8.20) | 13.0 (11.2–15.1) | <0.001 |
| Total NNAL (pmol/mg Cr)c | NNK | 0.22 (0.20–0.24) | 0.30 (0.28–0.34) | <0.001 |
| PheT (pmol/mg Cr) | PAH | 25.4 (23.6–27.3) | 29.0 (26.9–31.2) | <0.001 |
| MHBMA (pmol/mg Cr) | 1,3-Butadiene | 8.3 (7.2–9.7) | 11.3 (9.8–13.1) | <0.001 |
| HEMA (pmol/mg Cr) | Ethylene oxide | 13.6 (12.0–15.5) | 18.2 (15.9–20.7) | <0.001 |
| SPMA (pmol/mg Cr) | Benzene | 2.46 (2.16–2.80) | 2.96 (2.60–3.36) | 0.009 |
| HPMA (pmol/mg Cr) | Acrolein | 6712 (5845-7707) | 8882 (7726-10210) | <0.001 |
| HBMA (pmol/mg Cr) | Crotonaldehyde | 5749 (5022-6581) | 7915 (6906-9071) | <0.001 |
CI, confidence interval.
a
P’s and means and their 95% confidence intervals were derived from analysis of covariance with adjustment for matching factors, including age, neighborhood of residence and duration of biospecimen storage before laboratory analysis.
b
Two cases and four controls with missing total cotinine values were excluded from this analysis.
c
Eleven cases and 10 controls with missing total NNAL values were excluded from this analysis.