Table 1.
Characteristics of participants included in analyses, n = 126a
| Characteristic | European American n = 66 | African American n = 60 | P valueb |
|---|---|---|---|
| Male, no. (%) | 38 (58) | 35 (58) | .93 |
| Age in years, median (IQR) | 34 (25-45) | 41 (36-49) | <.01 |
| Body mass index, median (IQR) | 24 (22-28) | 27 (24-33) | <.01 |
| Menthol cigarette use, no. (%) | 18 (27) | 41 (68) | <.01 |
| Cigarettes/dayc, median (IQR) | 20 (14-20) | 15 (10-20) | .04 |
| Nicotine equiv. (nmol/mg-creat)d, median (IQR) | 63 (54-75) | 44 (37-53) | <.01 |
| Min from last cig, median (IQR) | 80 (50-107) | 90 (60-140) | .08 |
| Activity ratios (geometric mean, 95% CI) | |||
| NIC-Gluc/ free NIC | 0.33 (0.25-0.44) | 0.17 (0.13-0.23) | <.01 |
| COT-Gluc/ free COT | 1.03 (0.87-1.23) | 0.40 (0.28-0.57) | <.01 |
| 3HC-Gluc/ free 3HC | 0.19 (0.17-0.22) | 0.26 (0.23-0.30) | <.01 |
| NNAL-Gluc/ free NNAL | 2.06 (1.87-2.27) | 1.85 (1.61-2.12) | .33 |
a
128 participants in the original study, 67 European American and 61 African American: One sample dropped due to absence of urinary biomarkers and another due to poor genotyping call rate
b
P values: Non-parametric Wilcoxon ranksum test or chi square
c
Average of self-reported cigarettes/day in the three days before biomarker collection
d
Nicotine equivalents: Urinary sum of nicotine, cotinine, trans-3-hydroxycotinine and their glucuronide conjugates normalized to creatinine
IQR: interquartile range