Table 4:
Results for linear models for methylation of cg07555921 (AHRR), considered to be a marker for smoking
| Parameter | Estimate | Standard error | P-value |
|---|---|---|---|
| Model 1: Exposure variable only: frequency of heavy vehicular traffic (ref=never), n = 369 | |||
| Heavy vehicular traffic frequency: >10/hour | –0.10 | 0.11 | 0.4 |
| Heavy vehicular traffic frequency: 1–9/hour | 0.13 | 0.11 | 0.2 |
| Heavy vehicular traffic frequency: 10/day | –0.05 | 0.13 | 0.7 |
| Heavy vehicular traffic frequency: Seldom | 0.08 | 0.10 | 0.4 |
| Model 2: Smoking related variables only, n = 342 | |||
| Maternal smoking | –0.07 | 0.09 | 0.4 |
| Current smoking status | 0.77 | 0.08 | <.0001 |
| Smoking outside the home | 0.09 | 0.07 | 0.2 |
| Any environmental tobacco smoke exposure | –0.16 | 0.08 | 0.05 |
| Tobacco smoke exposure at 0–4 years | 0.09 | 0.06 | 0.2 |
| Tobacco smoke exposure at 10 years | 0.15 | 0.09 | 0.09 |
| Model 3: All variables considered apriori among all subjects, n = 329 | |||
| Heavy vehicular traffic frequency: >10/hour | –0.14 | 0.10 | 0.2 |
| Heavy vehicular traffic frequency: 1–9/hour | –0.04 | 0.10 | 0.7 |
| Heavy vehicular traffic frequency: 10/day | –0.08 | 0.13 | 0.5 |
| Heavy vehicular traffic frequency: Seldom | –0.04 | 0.09 | 0.7 |
| Maternal smoking | –0.10 | 0.10 | 0.3 |
| Current smoking status | 0.75 | 0.08 | <.0001 |
| Smoking outside the home | 0.11 | 0.07 | 0.1 |
| Any environmental tobacco smoke exposure | –0.18 | 0.09 | 0.04 |
| Tobacco smoke exposure at 0–4 years | 0.09 | 0.07 | 0.2 |
| Tobacco smoke exposure at 10 years | 0.17 | 0.09 | 0.06 |
| High SES (ref = low SES) | –0.22 | 0.13 | 0.1 |
| Mid SES (ref = low SES) | –0.04 | 0.09 | 0.6 |
| BMI | 0.02 | 0.01 | 0.007 |
| Gender | 0.04 | 0.07 | 0.5 |
| Model 4: All variables considered apriori among current smokers, n = 77 | |||
| Heavy vehicular traffic frequency: >10/hour | –0.13 | 0.30 | 0.7 |
| Heavy vehicular traffic frequency: 1–9/hour | 0.48 | 0.34 | 0.2 |
| Heavy vehicular traffic frequency: 10/day | 0.41 | 0.37 | 0.3 |
| Heavy vehicular traffic frequency: Seldom | 0.20 | 0.31 | 0.5 |
| Maternal smoking | –0.07 | 0.26 | 0.8 |
| Age subject started smoking | 0.20 | 0.06 | 0.002 |
| Smoking outside the home | 0.79 | 0.32 | 0.02 |
| Any environmental tobacco smoke exposure | –0.33 | 0.23 | 0.2 |
| Tobacco smoke exposure at 0–4 years | 0.14 | 0.20 | 0.5 |
| Tobacco smoke exposure at 10 years | 0.32 | 0.25 | 0.2 |
| High SES (ref = low SES) | –0.68 | 0.44 | 0.1 |
| Mid SES (ref = low SES) | –0.04 | 0.24 | 0.9 |
| BMI | 0.03 | 0.02 | 0.1 |
| Gender | 0.04 | 0.21 | 0.9 |
P-values in bold and bold italics denote statistical significance less than or equal to 0.05 and 0.1 respectively.