Table 1.
Demographics and urine biomarkers in Chinese and US smokers (values are medians and IQR, unless otherwise indicated)
| Chinese smokers (n=238) | US smokers (n=203) | p Value* | US men (n=118) | p Value* | |
|---|---|---|---|---|---|
| Age | 44.3 (43.0–45.5)† | 38.3 (36.7–39.8)† | <0.000‡ | 39–8 (3.77–41.8)† | 0.0001‡ |
| Male (%) | 238 (100%) | 118 (58%) | <0.0001 | 118 (100%) | |
| Tar | 12.2 (11.9–12.6)† | 13.6 (13.0–14.2)† | <0.0001‡ | 14.2 (13.4–14.9)† | <0.0001‡ |
| CPD | 18.0 (16.7–19.3)† | 19.5 (18.2–20.7)† | NS‡ | 20.6 (18.9–22.4)† | 0.02‡ |
| Nicotine Eq (nmol/mg creatinine) | 53.4 (32.8–78.9) | 54.8 (42.7–81.6) | NS | 54.6 (38.2–78.6) | NS |
| NNAL (pmol/mg creatinine) | 0.29 (0.18–0.47) | 1.19 (0.63–2.06) | <0.0001 | 1.12 (0.62–1.81) | <0.0001 |
| 1-HP (pmol/mg creatinine) | 3.64 (2.64–5.48) | 1.17 (0.75–1.79) | <0.0001 | 1.10 (0.70–1.52) | <0.0001 |
| 2-Nap (pmol/mg creatinine) | 103 (65.3–149) | 98.3 (59.7–149) | NS | 88.7 (52.0–130.3) | 0.03 |
| Sum of fluorenes (pmol/mg creatinine) | 23.5 (15.8–32.9) | 16.6 (10.8–24.5) | <0.0001 | 16.0 (10.6–22.4) | <0.0001 |
| Sum of phenanthrenes (pmol/mg creatinine) | 9.52 (6.56–13.5) | 3.54 (2.44–5.07) | <0.0001 | 3.53 (2.52–4.90) | <0.0001 |
| Sum of PAHs (pmol/mg creatinine) | 145 (95.8–201) | 123 (78.5–184) | 0.0082 | 110 (79–158) | 0.0001 |
| Nicotine Eq/CPD (nmol/mg creatinine) | 3.16 (1.76–5.23) | 3.13 (2.07–5.06) | NS | 2.87 (1.88–4.02) | NS |
| NNAL/CPD (fmol/mg creatinine) | 18.9 (11.3–32.7) | 73.4 (37.4–112) | <0.0001 | 62.1 (28.8–99.3) | <0.0001 |
| 1-HP/CPD (pmol/mg creatinine) | 0.24 (0.15–0.40) | 0.06 (0.04–0.10) | <0.0001 | 0.05 (0.04–0.08) | <0.0001 |
| 2-Nap/CPD (pmol/mg creatinine) | 6.04 (3.69–9.75) | 5.53 (3.54–8.37) | NS | 4.68 (3.10–6.52) | 0.0001 |
| Sum of fluorenes/CPD (pmol/mg creatinine) | 1.47 (0.93–2.21) | 0.98 (0.56–1.42) | <0.0001 | 0.82 (0.53–1.25) | <0.0001 |
| Sum of phenanthrenes/CPD (pmol/mg creatinine) | 0.60 (0.39–0.93) | 0.19 (0.13–0.29) | <0.0001 | 018 (0.11–0.29) | <0.0001 |
| Sum of PAHs/CPD (pmol/mg creatinine) | 8.41 (5.56–12.9) | 7.00 (4.55–10.3) | 0.0002 | 5.66 (4.02–8.25) | <0.0001 |
| NNAL/nicotine Eq×106 | 5.55 (3.74–11.8) | 22.0 (14.2–31.8) | <0.0001 | 21.5 (12.9–31.4) | <0.0001 |
| 1-HP/ nicotine Eq×103 | 0.07 (0.05–0.13) | 0.02 (0.01–0.03) | <0.0001 | 0.02 (0.01–0.03) | <0.0001 |
| 2-Nap/nicotine Eq ×103 | 1.91 (1.50–2.61) | 1.54 (1.13–2.42) | <0.0001 | 1.46 (1.05–2.36) | <0.0001 |
| Sum of fluorene/nicotine Eq×103 | 0.43 (0.33–0.61) | 0.29 (0.21–0.38) | <0.0001 | 0.30 (0.23–0.37) | <0.0001 |
| <0.0001 | |||||
| Sum of phenanthrene/nicotine Eq×103 | 0.16 (0.11–0.33) | 0.06 (0.04–0.08) | <0.0001 | 0.06 (0.04–0.08) | <0.0001 |
| Sum of PAHs/nicotine Eq×103 | 2.65 (2.08–3.68) | 1.99 (1.44–3.00) | <0.0001 | 1.81 (1.40–2.73) | <0.0001 |
*
Mann-Whitney rank sum test unless otherwise noted.
†
Mean and 95% CI.
‡
t test.
1-HP, 1-hydroxypyrene; 2-Nap, 2-naphthol; CPD, cigarettes per day; Eq, equivalents; NNAL, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol; NS, not significant; PAH, polycyclic aromatic hydrocarbon.