Table 4.
Percent Change of DNA Methylation in NOS3 Gene per log-transformed IQR increase in BC at different lag periods
| Lag period | NOS3 Gene loci | Model 1 | Model 2 | Model 3 | Model 4 | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Difference in % methylation | 95%CI | p | Difference in % methylation | 95%CI | p | Difference in % methylation | 95%CI | p | Difference in % methylation | 95%CI | p | ||
| Lag 0-6 h | Position 1 | −3.73 | (−6.98, − 0.47) | 0.03 | −3.31 | (−6.75, 0.13) | 0.06 | −4.90 | (−9.71, − 0.08) | 0.05 | −1.75 | (−4.66, 1.16) | 0.23 |
| Position 2 | −1.23 | (−4.48, 2.02) | 0.45 | −0.36 | (−3.79, 3.08) | 0.84 | 1.75 | (−3.90, 7.39) | 0.54 | 0.37 | (−3.01, 3.75) | 0.83 | |
| Position 3 | −1.70 | (−5.44, 2.04) | 0.37 | −1.26 | (−5.24, 2.72) | 0.53 | 1.02 | (−4.26, 6.29) | 0.70 | 1.59 | (−1.94, 5.13) | 0.37 | |
| Average | −2.17 | (−4.94, 0.61) | 0.12 | −1.58 | (−4.52, 1.36) | 0.29 | −0.70 | (−4.92, 3.52) | 0.74 | −0.11 | (−2.79, 2.56) | 0.93 | |
| Lag 7-12 h | Position 1 | −6.38 | (−9.61, − 3.15) | < 0.01 | −6.51 | (−9.93, − 3.08) | < 0.01 | −7.13 | (−11.76, − 2.50) | < 0.01 | −4.81 | (−7.64, − 1.99) | < 0.01 |
| Position 2 | −4.38 | (−7.70, − 1.06) | 0.01 | −3.92 | (−7.54, − 0.29) | 0.03 | −3.49 | (−9.07, 2.10) | 0.21 | −2.39 | (−5.98, 1.19) | 0.19 | |
| Position 3 | −4.65 | (−8.49, − 0.80) | 0.02 | −4.40 | (−8.54, − 0.26) | 0.04 | −2.88 | (−8.09, 2.34) | 0.27 | −2.25 | (−5.94, 1.44) | 0.23 | |
| Average | −5.31 | (−8.03, − 2.59) | < 0.01 | −5.51 | (−8.40, − 2.61) | < 0.01 | −4.57 | (−8.61, − 0.53) | 0.03 | −3.13 | (−5.84, − 0.43) | 0.02 | |
| Lag 13-24 h | Position 1 | −6.96 | (−9.78, − 4.14) | < 0.01 | −6.56 | (− 9.45, − 3.68) | < 0.01 | −8.12 | (−11.68, − 4.56) | < 0.01 | −4.99 | (−7.8, − 2.17) | < 0.01 |
| Position 2 | −4.47 | (−7.51, − 1.43) | < 0.01 | −4.09 | (−7.20, − 0.98) | 0.01 | −4.05 | (−8.49, 0.39) | 0.07 | −3.05 | (−6.58, 0.47) | 0.09 | |
| Position 3 | −1.90 | (−5.41, 1.60) | 0.28 | −1.14 | (−4.74, 2.46) | 0.53 | 0.43 | (−3.75, 4.62) | 0.84 | 0.60 | (−3.02, 4.21) | 0.74 | |
| Average | −4.58 | (−7.02, − 2.14) | < 0.01 | −4.37 | (− 6.92, − 1.82) | < 0.01 | −3.31 | (−6.57, − 0.04) | 0.05 | −2.65 | (−5.35, 0.05) | 0.05 | |
| Lag 0-24 h | Position 1 | −5.73 | (−8.25, − 3.21) | < 0.01 | −5.44 | (−8.07, − 2.82) | < 0.01 | −6.79 | (−10.27, − 3.31) | < 0.01 | −5.16 | (−8.43, − 1.89) | < 0.01 |
| Position 2 | −3.13 | (−5.73, − 0.53) | 0.02 | −2.71 | (−5.45, 0.03) | 0.05 | −2.17 | (−6.42, 2.08) | 0.31 | −2.37 | (−6.45, 1.70) | 0.25 | |
| Position 3 | −2.44 | (−5.46, 0.58) | 0.11 | −1.96 | (−5.16, 1.23) | 0.22 | −0.08 | (−4.06, 3.90) | 0.97 | 0.15 | (−4.1, 4.40) | 0.94 | |
| Average | −3.67 | (−5.79, − 1.54) | < 0.01 | −3.72 | (−5.97, − 1.46) | < 0.01 | −2.71 | (−5.82, 0.40) | 0.09 | −2.69 | (−5.82, 0.44) | 0.09 | |
| Lag 25-48 h | Position 1 | −1.94 | (−5.35, 1.48) | 0.26 | −2.25 | (−5.73, 1.23) | 0.20 | −2.48 | (−6.66, 1.70) | 0.24 | −3.48 | (−6.38, − 0.57) | 0.02 |
| Position 2 | −0.40 | (−4.06, 3.26) | 0.83 | −0.44 | (−4.16, 3.27) | 0.81 | 0.29 | (−4.50, 5.09) | 0.90 | −0.87 | (−4.45, 2.71) | 0.63 | |
| Position 3 | 1.81 | (−2.13, 5.76) | 0.36 | 1.36 | (−2.68, 5.40) | 0.50 | 1.66 | (−2.81, 6.12) | 0.46 | 1.19 | (−2.49, 4.87) | 0.52 | |
| Average | −0.50 | (−3.52, 2.51) | 0.74 | − 0.52 | (−3.57, 2.53) | 0.73 | −0.10 | (−3.69, 3.48) | 0.95 | −1.37 | (− 4.13, 1.40) | 0.32 | |
| Lag 49-72 h | Position 1 | 0.02 | (−3.71, 3.74) | 0.99 | −0.41 | (−4.47, 3.64) | 0.84 | 0.21 | (−5.3, 5.72) | 0.94 | 2.81 | (−1.03, 6.66) | 0.15 |
| Position 2 | 0.17 | (−3.81, 4.14) | 0.93 | 0.54 | (−3.79, 4.86) | 0.80 | 4.15 | (−2.13, 10.43) | 0.19 | 2.24 | (−2.41, 6.89) | 0.34 | |
| Position 3 | −1.87 | (−6.16, 2.42) | 0.39 | −2.44 | (−7.07, 2.20) | 0.30 | −0.46 | (−6.35, 5.43) | 0.87 | 0.47 | (−4.01, 4.96) | 0.83 | |
| Average | −0.81 | (−4.11, 2.49) | 0.62 | −0.76 | (−4.3, 2.79) | 0.67 | 1.32 | (−3.4, 6.04) | 0.58 | 1.95 | (−1.56, 5.46) | 0.27 | |
| Lag 73-96 h | Position 1 | −0.63 | (−4.35, 3.10) | 0.74 | −0.76 | (−4.61, 3.10) | 0.69 | −0.39 | (−4.98, 4.21) | 0.87 | −0.59 | (−4.33, 3.15) | 0.75 |
| Position 2 | −2.04 | (−5.71, 1.64) | 0.27 | −1.99 | (−5.82, 1.84) | 0.30 | −1.50 | (−6.62, 3.63) | 0.56 | −2.32 | (−6.67, 2.04) | 0.29 | |
| Position 3 | −3.62 | (−7.72, 0.48) | 0.08 | −4.00 | (− 8.25, 0.24) | 0.06 | −3.60 | (−8.38, 1.18) | 0.14 | −1.14 | (−5.53, 3.25) | 0.60 | |
| Average | −2.36 | (−5.44, 0.71) | 0.13 | −2.45 | (− 5.67, 0.77) | 0.13 | −1.90 | (−5.78, 1.98) | 0.33 | −1.72 | (−5.13, 1.68) | 0.31 | |
Note: All estimates are from linear mixed effect model to reflect percent changes in methylation per IQR increase in log-transformed BC. The IQR (μg/m3) was 1.8 for lag 0-6 h, 1.8 for lag 7-12 h, 1.2 for lag 13-24 h, 1.1 for lag 0-24 h, 1.5 for lag 25-48 h, 1.6 for lag 49-72 h and 1.3 for lag 73-96 h
Model 1 was the unadjusted model
Model 2 adjusted for day-of-week and week number when buccal cells were collected
Model 3 further adjusted for age, gender and race/ethnicity
Model 4 further adjusted for NO2