Table 3.
Repeated-measures mixed model results for log-transformed creatinine-corrected U-Hg measurements from annual visits at years 3, 4, and 5 of the New England Children’s Amalgam Trial.
| Current U-Hg (μg/g creatinine)a |
Cumulative U-Hg (μg/g creatinine)b |
|||||||
|---|---|---|---|---|---|---|---|---|
| Univariate models
|
Multivariate model
|
Univariate models
|
Multivariate model
|
|||||
| Characteristic | β (SE) | p-Value | β (SE) | p-Value | β (SE) | p-Value | β (SE) | p-Value |
| Amalgam surfaces, current nc | 0.10 (0.01) | < 0.001 | 0.09 (0.01) | < 0.001 | 0.05 (0.01) | < 0.001 | ||
| Posterior occlusal amalgam surfaces, current nc | 0.19 (0.01) | < 0.001 | 0.09 (0.02) | < 0.001 | ||||
| Amalgam surface-years | 0.01 (0.002) | < 0.001 | 0.02 (0.002) | < 0.001 | ||||
| Posterior occlusal amalgam surface-years | 0.03 (0.004) | < 0.001 | 0.05 (0.004) | < 0.001 | 0.03 (0.004) | < 0.001 | ||
| Age (years) | –0.12 (0.02) | < 0.001 | –0.12 (0.03) | < 0.001 | ||||
| LBM | –0.01 (0.001) | < 0.001 | –0.004 (0.001) | 0.004 | ||||
| Weight (kg) | –0.01 (0.002) | < 0.001 | –0.01 (0.002) | < 0.001 | –0.01 (0.002) | < 0.001 | –0.01 (0.002) | < 0.001 |
| Sex | ||||||||
| Male | 0.02 (0.09) | 0.82 | –0.01 (0.10) | 0.90 | ||||
| Female | reference | reference | ||||||
| Race/ethnicity | ||||||||
| Non-Hispanic black | –0.04 (0.12) | 0.77 | 0.27 (0.16) | 0.08 | ||||
| Hispanic | 0.18 (0.21) | 0.39 | 0.16 (0.23) | 0.49 | ||||
| Other | 0.06 (0.15) | 0.68 | 0.02 (0.17) | 0.87 | ||||
| Non-Hispanic white | reference | reference | ||||||
| SES | ||||||||
| Low | 0.08 (0.11) | 0.45 | 0.04 (0.12) | 0.72 | ||||
| Medium | 0.06 (0.11) | 0.60 | –0.004 (0.13) | 0.97 | ||||
| High | reference | reference | ||||||
| Chewing gum | ||||||||
| Daily | 0.44 (0.16) | 0.01 | 0.49 (0.14) | < 0.001 | 0.30 (0.15) | 0.05 | 0.23 (0.09) | 0.01 |
| Occasionally | 0.07 (0.12) | 0.52 | 0.19 (0.10) | 0.06 | 0.23 (0.10) | 0.03 | 0.06 (0.06) | 0.37 |
| Never | reference | reference | reference | reference | ||||
| Toothbrushing frequency | ||||||||
| ≥2/day | 0.03 (0.15) | 0.85 | 0.11 (0.13) | 0.39 | ||||
| 1/day | 0.08 (0.15) | 0.60 | 0.01 (0.12) | 0.96 | ||||
| < 1/day | reference | reference | ||||||
| Grinds teeth (yes vs. no) | 0.05 (0.13) | 0.70 | –0.05 (0.15) | 0.76 | ||||
| Fish consumptiond | ||||||||
| At least 1/week | –0.20 (0.11) | 0.31 | –0.15 (0.11) | 0.18 | ||||
| ≥2/month | –0.20 (0.11) | 0.37 | –0.05 (0.10) | 0.65 | ||||
| ≤ 1/month | –0.10 (0.10) | 0.08 | –0.07 (0.08) | 0.38 | ||||
| Never | reference | reference | ||||||
a
Measure taken during the same follow-up visit as the current amalgam exposure measure.
b
Sum of the individual U-Hg measures taken at each previous follow-up visit, and was calculated for visit 4 (using data from visits 3 and 4) and visit 5 (using data from visits 3, 4, and 5) only. Models including age, LBM, or weight were also adjusted for year of follow-up.
c
n = number restored with dental amalgam.
d
Fish consumption categories were mutually exclusive and referred to all types of fish and seafood.