| No asthma | Lifetime asthma | Current asthma | Early persistent asthma(diagnosis by 3 years) | Late onset asthma (diagnosis after 3 years) | |||||
| N | N | OR* (95% CI) | N | OR* (95% CI) | N | OR* (95% CI) | N | OR* (95% CI) | |
| EPHX1 metabolic phenotypes† | |||||||||
| Low | 1061 | 171 | 1.0 | 113 | 1.0 | 67 | 1.0 | 80 | 1.0 |
| Intermediate | 1116 | 193 | 1.07 (0.85 to 1.35) | 123 | 1.06 (0.80 to 1.41) | 70 | 0.92 (0.64 to 1.33) | 98 | 1.21 (0.88 to 1.66) |
| High | 471 | 112 | 1.51 (1.14 to 1.98) | 72 | 1.50 (1.08 to 2.09) | 38 | 1.28 (0.83 to 1.98) | 63 | 1.84 (1.28 to 2.64) |
| p for trend | 0.007 | 0.004 | 0.38 | 0.001 | |||||
| EPHX1 diplotypes‡ | |||||||||
| 113His–139His (low/low) | 1.0 | 1.0 | 1.0 | 1.0 | |||||
| 113Tyr–139His (fast/low) | 1.17 (0.97 to 1.41) | 1.19 (0.95 to 1.50) | 1.11 (0.84 to 1.47) | 1.26 (0.97 to 1.62) | |||||
| 113His–139Arg (low/fast) | 1.42 (0.87 to 2.33) | 1.61 (0.91 to 2.87) | 1.85 (0.94 to 3.65) | 1.09 (0.53 to 2.25) | |||||
| 113Tyr–139Arg (fast/fast) | 1.32 (1.04 to 1.67) | 1.33 (1.00 to 1.77) | 1.07 (0.73 to 1.55) | 1.61 (1.19 to 2.18) | |||||
*ORs adjusted for age, sex, race/ethnicity, in utero exposure to maternal smoking, number of smokers at home, community of residence, parental education, health insurance and parental history of asthma.
†See table E2 in the online supplement (available at http://thorax.bmj.com/supplemental) for determinations of the EPHX1 phenotypes based on Tyr113His and His139Arg polymorphisms. Low and fast within parentheses represent in vitro catalytic efficiency of the two EPHX1 polymorphisms in the order the alleles are presented before the parentheses.
‡The ORs are per increase of one copy of the given diplotype.