Table 2. Comparisons of body size in boys after adjusting for confounders among 4 dioxin groups.
| Percentile of PCDDs/Fs-TEQ (pg/gfat) | <25 | 25–50 | 50–75 | ≥75 | |||||||||
| Number of subjects | 30 | 37 | 28 | 25 | |||||||||
| Infant age | Parameter | Unit | Mean | SE | Mean | SE | p | Mean | SE | p | Mean | SE | p |
| At birth | Weight | abs. value (g) | 3289.9 | 73.0 | 3250.0 | 63.6 | 3253.3 | 73.0 | 3278.7 | 83.6 | |||
| age adj. Z | −0.226 | 0.154 | −0.341 | 0.134 | −0.309 | 0.154 | −0.281 | 0.177 | |||||
| Length | abs. value (cm) | 50.1 | 0.32 | 50.1 | 0.28 | 49.5 | 0.32 | 49.7 | 0.37 | ||||
| age adj. Z | 0.060 | 0.171 | 0.048 | 0.149 | −0.225 | 0.171 | −0.122 | 0.196 | |||||
| Head | abs. value (cm) | 33.8 | 0.30 | 33.7 | 0.26 | 33.0 | 0.30 | 33.5 | 0.34 | ||||
| age adj. Z | −0.394 | 0.235 | −0.516 | 0.205 | −1.024 | 0.235 | −0.786 | 0.269 | |||||
| BMI | abs. value | 13.1 | 0.25 | 12.9 | 0.22 | 13.2 | 0.25 | 13.2 | 0.29 | ||||
| age adj. Z | −0.296 | 0.195 | −0.437 | 0.170 | −0.178 | 0.195 | −0.214 | 0.224 | |||||
| Abdominal | abs. value (cm) | 32.3 | 0.37 | 32.0 | 0.32 | 31.8 | 0.37 | 32.2 | 0.42 | ||||
| Head/Length | abs. value | 0.675 | 0.006 | 0.673 | 0.005 | 0.667 | 0.006 | 0.673 | 0.006 | ||||
| 1 month | Weight | abs. value (g) | 4542.5 | 104.8 | 4498.3 | 90.5 | 4501.4 | 102.5 | 4328.0 | 117.9 | |||
| age adj. Z | 0.292 | 0.175 | 0.219 | 0.151 | 0.224 | 0.171 | −0.065 | 0.197 | |||||
| Length | abs. value (cm) | 56.1 | 0.42 | 55.5 | 0.36 | 56.1 | 0.41 | 55.7 | 0.47 | ||||
| age adj. Z | 1.204 | 0.219 | 0.799 | 0.189 | 1.108 | 0.214 | 0.928 | 0.247 | |||||
| Head | abs. value (cm) | 37.4 | 0.25 | 37.4 | 0.22 | 36.9 | 0.25 | 37.0 | 0.28 | ||||
| age adj. Z | 0.454 | 0.206 | 0.454 | 0.178 | 0.065 | 0.202 | 0.181 | 0.232 | |||||
| BMI | abs. value | 14.3 | 0.28 | 14.6 | 0.24 | 14.3 | 0.28 | 13.9 | 0.32 | ||||
| age adj. Z | −0.430 | 0.223 | −0.247 | 0.193 | −0.448 | 0.218 | −0.792 | 0.251 | |||||
| Abdominal | abs. value (cm) | 37.6 | 0.50 | 38.2 | 0.43 | 38.0 | 0.49 | 37.5 | 0.56 | ||||
| Head/Length | abs. value | 0.666 | 0.005 | 0.674 | 0.004 | 0.659 | 0.005 | c | 0.665 | 0.006 | |||
| 4 months | Weight | abs. value (g) | 6927.0 | 142.9 | 6990.0 | 124.8 | 7222.9 | 143.6 | 6562.1 | 163.6 | c,f | ||
| age adj. Z | −0.191 | 0.183 | −0.191 | 0.160 | 0.179 | 0.183 | −0.676 | 0.214 | f | ||||
| Length | abs. value (cm) | 64.7 | 0.37 | 64.0 | 0.32 | 65.3 | 0.37 | 64.3 | 0.42 | ||||
| age adj. Z | 0.260 | 0.182 | −0.190 | 0.159 | 0.485 | 0.182 | d | −0.037 | 0.212 | ||||
| Head | abs. value (cm) | 41.8 | 0.22 | 41.7 | 0.20 | 41.4 | 0.22 | 41.8 | 0.26 | ||||
| age adj. Z | −0.102 | 0.199 | −0.343 | 0.174 | −0.401 | 0.200 | −0.125 | 0.233 | |||||
| BMI | abs. value | 16.5 | 0.30 | 17.1 | 0.26 | 16.9 | 0.30 | 15.9 | 0.34 | c,e | |||
| age adj. Z | −0.510 | 0.211 | −0.152 | 0.184 | −0.163 | 0.211 | −0.931 | 0.246 | c,e | ||||
| Abdominal | abs. value (cm) | 41.7 | 0.48 | 42.6 | 0.42 | 43.3 | 0.48 | a | 40.8 | 0.55 | c,f | ||
| Head/Length | abs. value | 0.646 | 0.004 | 0.652 | 0.004 | 0.634 | 0.004 | d | 0.651 | 0.005 | e | ||
a: p<0.05, b: p<0.01 as compared with <25 percentile group, c: p<0.05, d: p<0.01 as compared with 25–50 percentile group, e: p<0.05, f: p<0.01 as compared with 50–75 percentile group.
Mean: adjusted mean, SE: standard error, p: p-value, abs. value: absolute value, age adj. Z: age adjusted z score.
Confounders for measurements of body size: parity (primipara or not), maternal age, weight, educational period (years), alcohol drinking during pregnancy (yes/no), family income, family smoking (yes/no), gestational weeks, infant age (days) on the day of each examination, and location difference (TK or ST hospital).
Confounders for z scores of body size: parity (primipara or not), maternal age, weight, educational period (years), alcohol drinking during pregnancy (yes/no), family income, family smoking (yes/no), gestational weeks, and location difference (TK or ST hospital).
Note: Body size at 1 month was missing for 2 boys.