Smoking behavior and chemical exposures while smoking reduced nicotine cigarettes
| . | Week 1, mean (95% CI) . | Week 6, mean (95% CI) . | Week 10, mean (95% CI) . | % difference week 6 versus week 1, mean (95% CI) . | % difference week 10 versus week 1, mean (95% CI) . | % difference week 10 versus week 6, mean (95% CI) . |
|---|---|---|---|---|---|---|
| Cigarettes per day | 18.9 (15.5-22.3) | 17.7 (10.4-25.0) | 10.1 (6.2-14.0) | −6 (−37-24) | −47 (−63 to −30) | −43 (−80 to −6) |
| Pre-smoking plasma nicotine (ng/mL) | 13.0 (10.2-15.7) | 3.8 (1.6-6.1) | 8.3 (4.1-12.4) | −70 (−101 to −40) | −36 (−76-4) | 115 (28-202) |
| Nicotine boost (ng/mL) | 8.2 (5.4-11.1) | 1.0 (0.6-1.4) | NM | −88 (−122 to −54) | NM | NM |
| Blood COHB (%) | 3.2 (2.6-3.9) | 3.6 (2.3-4.9) | 2.1 (1.2-3.0) | 11 (−22-45) | −35 (−64 to −7) | −42 (−66 to −18) |
| Plasma cotinine (ng/mL) | 194 (152-235) | 62 (28-96) | 109 (64-153) | −68 (−93 to −43) | −44 (−63 to −25) | 75 (9-142) |
| Total NNAL* (pmol/mg creat) | 1.17 (0.79-1.73) | 0.92 (0.58-1.44) | 0.53 (0.29-0.95) | −22 (−38-0) | −55 (−71 to −32) | −43 (−60 to −17) |
| 1-OH-pyrene* (pmol/mg creat) | 0.97 (0.62-1.33) | 1.06 (0.80-1.50) | 0.89 (0.62-1.33) | 18 (−12-57) | −6 (−44-56) | −20 (−46-16) |
| 2-Naphthol* (pmol/mg creat) | 77.9 (62.0-97.4) | 80.5 (62.0-104.4) | 57.5 (43.4-77.0) | 3 (−23-37) | −26 (−43 to −5) | −28 (−48 to −1) |
| Sum of hydroxyphenanthrene isomers* (pmol/mg creat) | 2.4 (1.8-3.4) | 2.6 (1.9-3.4) | 2.6 (1.7-3.8) | 6 (−23-45) | 5 (−25-47) | −1 (−24-30) |
| 2-Hydroxyfluorene* (pmol/mg creat) | 6.9 (5.1-9.3) | 7.8 (5.8-10.6) | 4.7 (2.9-7.7) | 13 (−15-50) | −32 (−58-11) | −39 (−60 to −9) |
| . | Week 1, mean (95% CI) . | Week 6, mean (95% CI) . | Week 10, mean (95% CI) . | % difference week 6 versus week 1, mean (95% CI) . | % difference week 10 versus week 1, mean (95% CI) . | % difference week 10 versus week 6, mean (95% CI) . |
|---|---|---|---|---|---|---|
| Cigarettes per day | 18.9 (15.5-22.3) | 17.7 (10.4-25.0) | 10.1 (6.2-14.0) | −6 (−37-24) | −47 (−63 to −30) | −43 (−80 to −6) |
| Pre-smoking plasma nicotine (ng/mL) | 13.0 (10.2-15.7) | 3.8 (1.6-6.1) | 8.3 (4.1-12.4) | −70 (−101 to −40) | −36 (−76-4) | 115 (28-202) |
| Nicotine boost (ng/mL) | 8.2 (5.4-11.1) | 1.0 (0.6-1.4) | NM | −88 (−122 to −54) | NM | NM |
| Blood COHB (%) | 3.2 (2.6-3.9) | 3.6 (2.3-4.9) | 2.1 (1.2-3.0) | 11 (−22-45) | −35 (−64 to −7) | −42 (−66 to −18) |
| Plasma cotinine (ng/mL) | 194 (152-235) | 62 (28-96) | 109 (64-153) | −68 (−93 to −43) | −44 (−63 to −25) | 75 (9-142) |
| Total NNAL* (pmol/mg creat) | 1.17 (0.79-1.73) | 0.92 (0.58-1.44) | 0.53 (0.29-0.95) | −22 (−38-0) | −55 (−71 to −32) | −43 (−60 to −17) |
| 1-OH-pyrene* (pmol/mg creat) | 0.97 (0.62-1.33) | 1.06 (0.80-1.50) | 0.89 (0.62-1.33) | 18 (−12-57) | −6 (−44-56) | −20 (−46-16) |
| 2-Naphthol* (pmol/mg creat) | 77.9 (62.0-97.4) | 80.5 (62.0-104.4) | 57.5 (43.4-77.0) | 3 (−23-37) | −26 (−43 to −5) | −28 (−48 to −1) |
| Sum of hydroxyphenanthrene isomers* (pmol/mg creat) | 2.4 (1.8-3.4) | 2.6 (1.9-3.4) | 2.6 (1.7-3.8) | 6 (−23-45) | 5 (−25-47) | −1 (−24-30) |
| 2-Hydroxyfluorene* (pmol/mg creat) | 6.9 (5.1-9.3) | 7.8 (5.8-10.6) | 4.7 (2.9-7.7) | 13 (−15-50) | −32 (−58-11) | −39 (−60 to −9) |
NOTE: Week 1 is while smoking usual brand. Week 6 is while smoking the lowest RNC cigarette (1 mg). Week 10 is 4 weeks after the end of RNC smoking. Values in bold indicate significant differences (P < 0.05).
Geometric means; NM = not measured; creat = creatinine.