Table 4.
Associations (95% CI) between arsenic biomarkers and gestational age (weeks) within levels of one-carbon metabolism factors
| Biomarker | Level | Model 1a β (95% CI) | p | Model 2b β (95% CI) | p | Model 3c β (95% CI) N = 145 | p |
|---|---|---|---|---|---|---|---|
| % U-iAs | Normal B12 | 0 (− 0.05, 0.05) | 0 (− 0.05, 0.05) | − 0.01 (− 0.06, 0.05) | |||
| B12 deficient | 0.01 (− 0.06, 0.08) | 0.87 | 0.01 (− 0.06, 0.08) | 0.93 | 0.01 (− 0.07, 0.09) | 0.97 | |
| Normal homocysteine | 0 (− 0.04, 0.05) | 0.02 (− 0.03, 0.07) | 0 (− 0.05, 0.05) | ||||
| Hyperhomocysteinemia | − 0.02 (− 0.19, 0.15) | 0.92 | − 0.02 (− 0.10, 0.06) | 0.92 | − 0.02 (− 0.26, 0.22) | 0.90 | |
| B12 > median | 0.02 (− 0.04, 0.07) | 0.03 (− 0.02, 0.08) | 0.01 (− 0.04, 0.07) | ||||
| B12 < =median | − 0.02 (− 0.10, 0.06) | 0.36 | − 0.06 (− 0.15, 0.04) | 0.39 | 0 (− 0.09, 0.09) | 0.65 | |
| Folate >median | 0.02 (− 0.03, 0.07) | 0 (− 0.04, 0.05) | 0.02 (− 0.03, 0.07) | ||||
| Folate <=median | − 0.05 (− 0.15, 0.04) | 0.09 | − 0.01 (− 0.20, 0.19) | 0.07 | − 0.05 (− 0.15, 0.06) | 0.21 | |
| Homocysteine <median | 0.01 (− 0.05, 0.06) | 0.01 (− 0.05, 0.06) | 0 (− 0.06, 0.05) | ||||
| Homocysteine > = median | − 0.01 (− 0.10, 0.07) | 0.63 | − 0.01 (− 0.10, 0.08) | 0.67 | 0.01 (− 0.09, 0.11) | 0.96 | |
| % U-MMAs | Normal B12 | −0.01 (− 0.11, 0.08) | − 0.02 (− 0.11, 0.08) | − 0.03 (− 0.13, 0.07) | |||
| B12 deficient | −0.06 (− 0.13, 0.02) | 0.35 | − 0.06 (− 0.13, 0.01) | 0.36 | −0.04 (− 0.12, 0.04) | 0.72 | |
| Normal homocysteine | −0.04 (− 0.10, 0.02) | 0.01 (− 0.07, 0.08) | − 0.04 (− 0.11, 0.03) | ||||
| Hyperhomocysteinemia | 0.01 (− 0.13, 0.15) | 0.67 | −0.09 (− 0.18, 0) | 0.57 | 0.03 (− 0.16, 0.21) | 0.66 | |
| B12 > median | 0 (−0.07, 0.08) | 0.01 (− 0.06, 0.08) | 0 (−0.08, 0.08) | ||||
| B12 < =median | −0.09 (− 0.17, 0) | 0.10 | − 0.11 (− 0.22, 0) | 0.08 | −0.05 (− 0.16, 0.06) | 0.43 | |
| Folate >median | 0 (−0.07, 0.07) | −0.04 (− 0.11, 0.02) | 0.01 (− 0.07, 0.08) | ||||
| Folate <=median | −0.1 (− 0.21, 0) | 0.08 | 0 (− 0.16, 0.17) | 0.04 | − 0.12 (− 0.24, 0.01) | 0.11 | |
| Homocysteine <median | −0.06 (− 0.15, 0.03) | −0.06 (− 0.15, 0.03) | −0.07 (− 0.17, 0.03) | ||||
| Homocysteine > = median | −0.02 (− 0.10, 0.06) | 0.40 | −0.02 (− 0.10, 0.06) | 0.44 | 0.01 (− 0.08, 0.10) | 0.25 | |
| % U-DMAs | Normal B12 | 0 (−0.03, 0.04) | 0 (−0.03, 0.04) | 0.01 (−0.03, 0.05) | |||
| B12 deficient | 0.02 (−0.03, 0.06) | 0.41 | 0.02 (−0.03, 0.06) | 0.44 | 0.01 (−0.04, 0.06) | 0.70 | |
| Normal homocysteine | 0.01 (−0.02, 0.04) | −0.01 (− 0.04, 0.02) | 0.01 (− 0.02, 0.04) | ||||
| Hyperhomocysteinemia | 0 (−0.09, 0.09) | 0.90 | 0.04 (−0.02, 0.09) | 0.84 | −0.01 (− 0.13, 0.12) | 0.89 | |
| B12 > median | −0.01 (− 0.04, 0.03) | − 0.01 (− 0.04, 0.02) | 0 (− 0.04, 0.03) | ||||
| B12 < =median | 0.04 (− 0.02, 0.09) | 0.11 | 0.06 (0, 0.12) | 0.11 | 0.02 (−0.05, 0.08) | 0.42 | |
| Folate >median | −0.01 (− 0.04, 0.02) | 0.01 (− 0.02, 0.04) | − 0.01 (− 0.04, 0.02) | ||||
| Folate <=median | 0.06 (0, 0.12) | 0.03 | 0 (−0.10, 0.11) | 0.01 | 0.06 (−0.01, 0.13) | 0.07 | |
| Homocysteine <median | 0.01 (−0.03, 0.05) | 0.01 (−0.03, 0.05) | 0.01 (−0.03, 0.05) | ||||
| Homocysteine > = median | 0.01 (−0.04, 0.06) | 0.91 | 0.01 (−0.04, 0.06) | 0.89 | −0.01 (− 0.06, 0.05) | 0.70 | |
| C-tAs | Normal B12 | 1.53 (−0.01, 3.08) | 1.50 (−0.04, 3.04) | 1.46 (−0.06, 2.98) | |||
| B12 deficient | 0.39 (−0.63, 1.41) | 0.10 | 0.38 (−0.65, 1.41) | 0.11 | 0.18 (−1.47, 1.83) | 0.06 | |
| Normal homocysteine | 0.94 (0.03, 1.85) | 1.91 (0.44, 3.38) | 0.99 (−0.28, 2.26) | ||||
| Hyperhomocysteinemia | −0.37 (−3.33, 2.60) | 0.77 | 0.28 (−0.74, 1.31) | 0.83 | −0.97 (−4.34, 2.40) | 0.63 | |
| B12 > median | 2.16 (0.70, 3.62) | 0.18 (−0.84, 1.20) | 1.90 (0.38, 3.43) | ||||
| B12 < =median | 0.30 (−0.71, 1.31) | 0.14 | 2.41 (0.87, 3.95) | 0.11 | 0.10 (−1.76, 1.95) | 0.07 | |
| Folate >median | 0.15 (−0.86, 1.16) | 0.96 (0.05, 1.88) | −0.45 (−2.32, 1.41) | ||||
| Folate <=median | 2.38 (0.87, 3.88) | 0.21 | −0.42 (−4.25, 3.41) | 0.20 | 2.34 (0.74, 3.93) | 0.86 | |
| Homocysteine <median | 2.26 (0.54, 3.98) | 2.32 (0.57, 4.07) | 2.87 (0.91, 4.83) | ||||
| Homocysteine > = median | 0.48 (−0.66, 1.62) | 0.10 | 0.53 (−0.63, 1.68) | 0.09 | −0.37 (−2.16, 1.42) | 0.18 |
p-values represent a likelihood ratio test comparing the main effects model to a full model including an interaction term
NS Not significant
aModel 1 adjusts for smoking status during pregnancy, maternal age, and U-tAs
bModel 2 adjusts for smoking status during pregnancy, maternal age, U-tAs, and additional one-carbon metabolism factors
cModel 3 adjusts for smoking status during pregnancy, maternal age, and U-tAs and excludes mothers reporting recent seafood intake