Table 2.
Associations of NMR with withdrawal and physiological measurements (mean (SD) or median (range))
| After overnight abstinence (i.e., before Cig 1) | After 6 hours of abstinence (i.e., before Cig 3) | |||||||
|---|---|---|---|---|---|---|---|---|
| Variable | All (n = 136) | Slow NMR (n = 71) | Fast NMR (n = 65) | P value | All (n = 136) | Slow NMR (n = 71) | Fast NMR (n = 65) | P value |
| Plasma nicotine (ng/mL) | 1.0 (0.7–6.7) | 1.5 (0.7–6.7) | 0.7 (0.7–6.6) | <0.001 | 1.4 (0.7–8.9) | 2.25 (0.7–8.9) | 1.2 (0.7–3.4) | <0.001 |
| Expired CO (ppm) | 9 (2–22) | 9 (3–22) | 8 (2–21) | 0.31 | 8 (2–16) | 9 (3–16) | 8 (2–14) | 0.022 |
| HR (bpm) | 69.8 (9.1) | 69.6 (9.4) | 70 (8.9) | 0.816 | 72.2 (10.2) | 72.4 (10.2) | 72 (10.2) | 0.804 |
| QSU Global Craving Score | 4 (1–7) | 3.9 (1–6.4) | 4.3 (1–7) | 0.203 | 3.85 (1–7) | 3.7 (1–7) | 3.9 (1.5–7) | 0.016 |
| MNWS | 7 (0–32) | 6 (0–22) | 8 (1–32) | 0.087 | 8 (0–48) | 8 (0–21) | 9 (1–48) | 0.057 |
| PANAS negative | 12 (10–35) | 12 (10–24) | 13 (10–35) | 0.178 | 11 (10–30) | 11 (10–20) | 12 (10–30) | 0.059 |
| PANAS positive | 26 (3–46) | 26.5 (3–45) | 26 (11–46) | 0.790 | 24 (10–50) | 24 (10–50) | 22 (10–50) | 0.493 |
Bold numbers indicate significant differences (P < 0.05) between slow and fast metabolizers.
Cig 1 and 3, first and third cigarettes of the day, respectively; CO, carbon monoxide; HR, heart rate; MNWS, Minnesota Nicotine Withdrawal Scale; NMR, nicotine metabolite ratio; PANAS, Positive and Negative Affect Schedule; QSU, Questionnaire on Smoking Urges-Brief.