Table 4.
Geometric means (95% confidence limits) for EB–GII (fmol/ml) stratified by tertiles of CYP2A6 activity and race/ethnicity among smokers
| Values of CYP2A6 by tertilese | N | Geometric mean (95% CI)a,b | β a,b | P-valuea,b | P-trenda,b,c | Geometric mean (95% CI)d | β d | P-valued | P-trendd |
|---|---|---|---|---|---|---|---|---|---|
| Alla | 331 | ||||||||
| Tertile 1 | 110 | 0.71 (0.55–0.90) | Reference | 0.081 | 0.75 (0.57–0.95) | Reference | 0.245 | ||
| Tertile 2 | 111 | 1.00 (0.78–1.26) | 0.340 | 0.056 | 1.00 (0.78–1.25) | 0.290 | 0.101 | ||
| Tertile 3 | 110 | 0.99 (0.76–1.25) | 0.327 | 0.073 | 0.93 (0.72–1.18) | 0.223 | 0.227 | ||
| Whitesb | 113 | ||||||||
| Tertile 1 | 16 | 0.74 (0.37–1.42) | Reference | 0.856 | 0.87 (0.44–1.67) | Reference | 0.616 | ||
| Tertile 2 | 44 | 0.85 (0.56–1.25) | 0.140 | 0.722 | 0.88 (0.58–1.28) | 0.009 | 0.981 | ||
| Tertile 3 | 53 | 0.82 (0.37–1.42) | 0.108 | 0.776 | 0.75 (0.51–1.08) | −0.140 | 0.718 | ||
| Native Hawaiiansb | 110 | ||||||||
| Tertile 1 | 36 | 0.58 (0.38–0.86) | Reference | 0.281 | 0.61 (0.40–0.91) | Reference | 0.465 | ||
| Tertile 2 | 39 | 0.71 (0.47–1.04) | 0.201 | 0.481 | 0.70 (0.46–1.02) | 0.135 | 0.640 | ||
| Tertile 3 | 35 | 0.79 (0.51–1.18) | 0.312 | 0.284 | 0.76 (0.49–1.14) | 0.216 | 0.467 | ||
| Japanese Americansb | 108 | ||||||||
| Tertile 1 | 58 | 0.98 (0.69–1.37) | Reference | 0.084 | 0.99 (0.70–1.38) | Reference | 0.100 | ||
| Tertile 2 | 28 | 1.80 (1.10–2.90) | 0.601 | 0.048 | 1.79 (1.09–2.89) | 0.589 | 0.054 | ||
| Tertile 3 | 22 | 1.56 (0.90–2.68) | 0.464 | 0.156 | 1.54(0.89–2.65) | 0.443 | 0.178 |
Bold values denote statistical significance.
aThe overall analyses have been adjusted for sex, age, BMI, batch and race/ethnicity. β values correspond to the difference in EB–GII adducts (fmol/ml) for the second and third tertiles compared with the first tertile.
bThe race/ethnic specific analyses have been adjusted for sex, age, BMI and batch.
cA P-value for trend was calculated to determine whether the noted shift from tertiles 1–3 is statistically significant.
dIn addition to the model adjustments from a and b above, these analyses have been further adjusted for NE for both the overall and race/ethnic specific results. β values correspond to the difference in EB–GII adducts (fmol/ml) per change in tertile.
eCYP2A6 tertile range are as follows: Tertile 1 (0.0412–0.495), N = 110 | Tertile 2 (0.496–1.195), N = 111 | Tertile 3 (1.200–18.148), N = 110.