Table 2.
Smoking behavior and chemical exposures while smoking reduced nicotine yield cigarettes
| Week 1, mean (95% CI) | Week 6, mean (95% CI) | Week 10, mean (95% CI) | Week 6-week 1, mean % difference (95% CI) | Week 10-week 1, mean % difference (95% CI) | Week 10-week 6, mean % difference (95% CI) | |
|---|---|---|---|---|---|---|
| Cigarettes per day | 19.1 (15.6–22.6) | 22.4 (17.5–27.3) | 15.1 (11.4–18.7) | 17 (−4 to 39) | −21 (−52 to 9) | −33 (−57 to −8) |
| Pre-smoking plasma nicotine (ng/mL) | 14.1 (8.5–19.7) | 7.4 (4.8–10.0) | 8.8 (4.6–13.0) | −48 (−81 to −15) | −38 (−68 to −7) | 19 (−27 to 66) |
| Nicotine boost (ng/mL) | 9.6 (7.4–11.8) | 3.8 (2.7–4.9) | Not measured | −61 (−81 to −40) | Not measured | Not measured |
| Blood carboxyhemoglobin (%) | 3.3 (2.4–4.2) | 2.5 (1.8–3.1) | 1.9 (1.1–2.8) | −26 (−43 to −8) | −41 (−71 to −12) | −21 (−56 to 14) |
| Plasma cotinine (ng/mL) | 180 (122–237) | 107 (73–142) | 140 (78–201) | −40 (−61 to −20) | −22 (−48 to 4) | 30 (−11 to 71) |
| Total NNAL* (pmol/mg creatinine) | 1.08 (0.70–1.67) | 0.69 (0.47–1.02) | 0.61 (0.36–1.01) | −36 (−49 to −20) | −44 (−64 to −13) | −13 (−42 to 31) |
| 2-Naphthol* (pmol/mg creatinine) | 75.3 (55.7–101.8) | 52.88 (42.2–66.1) | 49.98 (35.7–69.9) | −30 (−42 to −15) | −34 (−55 to −2) | −5 (−34 to 35) |
| 1-Hydroxyphenanthrene* (pmol/mg creatinine) | 1.09 (0.85–1.41) | 0.77 (0.58–1.03) | 1.11 (0.79–1.54) | −29 (−56 to 13) | 1 (−34 to 55) | 43 (−6 to 117) |
| 2-Hydroxyphenanthrene* (pmol/mg creatinine) | 0.58 (0.44–0.76) | 0.52 (0.39–0.69) | 0.52 (0.36–0.75) | −10 (−38 to 30) | −11 (−39 to 30) | −1 (−33 to 46) |
| 3+4-Hydroxyphenanthrene * (pmol/mg creatinine) | 1.45 (1.09–1.92) | 1.21 (0.92–1.59) | 1.27 (0.89–1.82) | −16 (−31 to 2) | −12 (−39 to 27) | 5 (−23 to 42) |
| Total hydroxyphenanthrene* (pmol/mg creatinine) | 3.23 (2.57–4.06) | 2.64 (2.09–3.34) | 3.01 (2.21–4.11) | −18 (−37 to 6) | −7 (−32 to 29) | 14 (−15 to 53) |
| 1-Hydroxypyrene * (pmol/mg creatinine) | 1.63 (1.23–.16) | 1.04 (0.76–1.43) | 1.30 (0.82–2.07) | −36 (−52 to −15) | −20 (−49 to 25) | 25 (−16 to 85) |
| 2-Hydroxyfluorene * (pmol/mg creatinine) | 8.19 (5.50–12.19) | 6.25 (4.44–8.79) | 6.58 (4.53–9.56) | −24 (−45 to 7) | −20 (−51 to 32) | 5 (−28 to 54) |
NOTE: Week 1 is while smoking usual brand. Week 6 is while smoking the lowest yield commercial cigarette (0.1 mg nicotine). Week 10 is 4 weeks after the end of smoking reduced nicotine yield cigarettes. Analysis based on 20 subjects, including 2 subjects who quit smoking at week 10. Significant differences in bold (P < 0.05).
*
Geometric mean.