Metabolites of nicotine and carcinogen levels by nominal tar ratings
| Nominal tar rating (per cigarette)* | 15 mg | 13 mg | 12 mg | 10 mg | 8 mg | rS | p Value† |
| Demographics | |||||||
| Sample size | 175 | 43 | 74 | 51 | 165 | ||
| Age in years, mean (SD) | 44.5 (8.9) | 46.9 (8.1) | 42.2 (8.1) | 43.3 (10.5) | 43.3 (9.5) | 0.075 | 0.089 |
| Education, N (%) | −0.063 | 0.154 | |||||
| Junior high school and below | 52 (30%) | 26 (60%) | 19 (26%) | 19 (37%) | 42 (25%) | ||
| Secondary technical school | 93 (53%) | 13 (30%) | 37 (50%) | 27 (53%) | 86 (52%) | ||
| Junior college | 21 (12%) | 4 (9%) | 11 (15%) | 4 (8%) | 27 (16%) | ||
| College and above | 9 (5%) | 0 (0%) | 7 (9%) | 1 (2%) | 10 (6%) | ||
| Employment status, N (%) | 0.022 | 0.617 | |||||
| Employed | 164 (94%) | 38 (88%) | 69 (93%) | 45 (88%) | 152 (92%) | ||
| Unemployed | 11 (6%) | 5 (12%) | 5 (7%) | 6 (12%) | 13 (8%) | ||
| Monthly income, N (%) | 0.039 | 0.373 | |||||
| <500 yuan | 7 (4%) | 5 (12%) | 4 (5%) | 5 (10%) | 8 (5%) | ||
| 500–999 yuan | 1 (1%) | 3 (7%) | 0 (0%) | 1 (2%) | 6 (4%) | ||
| 1000–1999 yuan | 30 (17%) | 18 (42%) | 9 (12%) | 5 (10%) | 32 (19%) | ||
| 2000–4999 yuan | 107 (61%) | 16 (37%) | 47 (64%) | 32 (63%) | 100 (61%) | ||
| ≥5000 yuan | 30 (17%) | 1 (2%) | 14 (19%) | 8 (16%) | 19 (12%) | ||
| Change in daily consumption after switching from regular cigarettes (15 mg) to cigarettes with lower disclosed tar ratings | −0.052 | 0.398 | |||||
| Decreased daily consumption | 11% | 14% | 14% | 13% | |||
| No change in daily consumption | 56% | 64% | 57% | 52% | |||
| Increased daily consumption | 33% | 21% | 28% | 34% | |||
| Cigarettes/day‡ | 20 (10–20) | 18 (10–20) | 11 (10–20) | 20 (10–20) | 15 (10–20) | 0.152 | 0.001 |
| Nicotine metabolites* | |||||||
| Cotinine (μg/mg creatinine) | 16.1 (8.9–27.0) | 14.4 (7.2–32.7) | 12.8 (7.1–20.4) | 14.9 (7.6–28.0) | 16.1 (8.2–25.4) | 0.012 | 0.654 |
| Cotinine/cigarette (μg/mg creatinine) | 0.84 (0.56–1.50) | 0.93 (0.56–2.12) | 0.91 (0.60–1.66) | 0.71 (0.42–1.75) | 1.00 (0.56–1.85) | −0.068 | 0.123 |
| Trans-3′-hydroxycotinine (μg/mg creatinine) | 33.3 (16.4–63.4) | 37.2 (19.3–74.4) | 25.8 (10.9–48.0) | 31.9 (19.2–64.9) | 38.0 (16.9–62.6) | 0.001 | 0.974 |
| Trans-3′-hydroxycotinine/cigarette (μg/mg creatinine) | 2.02 (0.92–3.36) | 1.99 (1.00–4.51) | 2.04 (0.76–4.14) | 2.02 (1.06–3.51) | 2.39 (1.26–4.11) | −0.071 | 0.109 |
| Carcinogens* | |||||||
| Sample size | 60 | 14 | 28 | 18 | 56 | ||
| Total PAHs (pmol/mg creatinine) | 153 (95–195) | 159 (113–206) | 142 (94–177) | 152 (105–224) | 121 (88–166) | 0.125 | 0.099 |
| Total PAHs/cigarette (pmol/mg creatinine) | 8.46 (5.31–13.22) | 8.33 (6.99–16.08) | 9.66 (6.99–14.30) | 10.4 (5.36–16.42) | 6.72 (4.40–10.98) | 0.109 | 0.149 |
| NNAL (pmol/mg creatinine) | 0.22 (0.16–0.37) | 0.35 (0.22–0.41) | 0.26 (0.20–0.36) | 0.33 (0.22–0.45) | 0.292 (0.190–0.479) | −0.148 | 0.050 |
| NNAL/cigarette (pmol/mg creatinine) | 0.0160 (0.00918–0.0220) | 0.0217 (0.0118–0.0402) | 0.0212 (0.0121–0.0406) | 0.0198 (0.0146–0.0352) | 0.0200 (0.0111–0.0324) | −0.146 | 0.053 |
↵* The tabulated results in this table do not include three participants who smoked 5 mg tar cigarettes, one who smoked 9 mg cigarettes, three who smoked 11 mg cigarettes and one who smoked 14 mg tar cigarettes because of small numbers. These data are, however, included in the calculation of the Spearman rank order correlations and associated p values.
↵† These are bivariate p values; there was no adjustment for any demographic variables.
↵‡ Median (IQR).
NNAL, 4-(methylnitrosamino)-1-(3-pyridyl)-butanol; PAH, polycyclic aromatic hydrocarbon metabolites.