TABLE 3. Log-binomial Regression Analysis of the Associations Between Urinary Arsenic Concentrations (μg/l) in Quartiles (Children's Urinary Arsenic Concentrations and the Mothers’ Urinary Arsenic Concentrations at GW8) and Not Responding to the Injected PPD (Induration <5 mm) in Children at 4.5 Years of Age.
| Quartiles of U-As; range (median) | All children | ||
|---|---|---|---|
| Cases (non-responders) | Crude RR (95% CI) | Adjusted RR (95% CI)a | |
| U-As at 4.5 years of age (μg/l) (n = 577) | |||
| 12–34 (27), reference | 59 | 1.00 | 1.00 |
| 35–57 (44) | 61 | 1.04 (0.79, 1.37) | 1.03 (0.79, 1.36) |
| 58–125 (84) | 64 | 1.09 (0.84, 1.43) | 1.10 (0.84, 1.43) |
| 126–1228 (232) | 80 | 1.37 (1.07, 1.74) | 1.37 (1.07, 1.74) |
| p for trend | 0.003 | 0.003 | |
| U-As at GW8 (μg/l) (n = 560) | |||
| 2–38 (27), reference | 56 | 1.00 | 1.00 |
| 39–77 (51) | 65 | 1.16 (0.89, 1.52) | 1.15 (0.88, 1.51) |
| 78–211 (128) | 65 | 1.16 (0.89, 1.52) | 1.15 (0.88, 1.51) |
| 212–2064 (418) | 71 | 1.26 (0.98, 1.64) | 1.28 (0.99, 1.67) |
| p for trend | 0.129 | 0.092 | |
| Combined exposure (n = 560)b | |||
| U-As at 4.5 years of age (μg/l) | |||
| 12–34 (27), reference | 55 | 1.00 | 1.00 |
| 35–57 (44) | 61 | 1.09 (0.83, 1.44) | 1.08 (0.82, 1.43) |
| 58–125 (84) | 63 | 1.12 (0.85, 1.48) | 1.12 (0.85, 1.48) |
| 126–1228 (232) | 78 | 1.36 (1.03, 1.80) | 1.36 (1.03, 1.79) |
| p for trend | 0.018 | 0.019 | |
| U-As at GW8 (μg/l) | |||
| 2–38 (27), reference | 56 | 1.00 | 1.00 |
| 39–77 (51) | 65 | 1.13 (0.86, 1.48) | 1.12 (0.85, 1.47) |
| 78–211 (128) | 65 | 1.06 (0.80, 1.41) | 1.06 (0.79, 1.40) |
| 212–2064 (418) | 71 | 1.10 (0.82, 1.47) | 1.11 (0.83, 1.49) |
| p for trend | 0.789 | 0.678 | |
Note: U-As, sum of urinary arsenic metabolites; RR, relative risk; CI, confidence interval; GW, gestational week.
aAdjusted for age, gender, and SES.
bU-As concentrations at 4.5 years of age and GW8 entered in the same model.