Table 2.
Characteristics of children in the present study (N = 304)
| Variables | Mean ± SD, N (%) | P-value | ||
|---|---|---|---|---|
| Overall | Boys (n = 160) | Girls (n = 144) | ||
| Child’s age (months) | 47.7 ± 2.1 | 47.7 ± 2.0 | 47.8 ± 2.1 | 0.4569 |
| Body mass index | 15.7 ± 1.3 | 15.8 ± 1.2 | 15.7 ± 1.3 | 0.4508 |
| Birth weight (kg) | 3.3 ± 0.4 | 3.3 ± 0.4 | 3.2 ± 0.4 | 0.0274 |
| Feeding | 0.8972 | |||
| Breast feeding only | 77 (34.5) | 38 (31.7) | 39 (37.9) | |
| Breast and bottle feeding | 124 (55.6) | 73 (60.8) | 51 (49.5) | |
| Bottle feeding only | 22 (9.9) | 9 (7.5) | 13 (12.6) | |
| Place of childcare | 0.5199 | |||
| Home | 177 (65.8) | 94 (64.0) | 83 (68.0) | |
| Daycare or other | 92 (34.2) | 53 (36.1) | 39 (32.0) | |
| Second hand smoke exposure | 0.0477 | |||
| No | 221 (72.7) | 115 (71.9) | 106 (73.6) | |
| Yes | 83 (27.3) | 45 (28.1) | 38 (26.4) | |
| Canned food or drink | 0.0011 | |||
| < 1 per week | 259 (85.2) | 126 (78.8) | 133 (92.4) | |
| ≥ 1 per week | 45 (14.8) | 34 (21.3) | 11 (7.6) | |
| Instant rice | 0.1246 | |||
| < 1 per week | 300 (98.7) | 156 (97.5) | 144 (100.0) | |
| ≥ 1 per week | 4 (1.3) | 4 (2.5) | ||
| Use of plastic dishes in the microwave oven | 0.8831 | |||
| No | 247 (81.3) | 129 (80.6) | 118 (81.9) | |
| Yes | 57 (18.8) | 31 (19.4) | 26 (18.1) | |
| BPA at 4 years of age (μg/L) | 3.2 ± 5.0 | 3.2 ± 3.1 | 3.3 ± 6.6 | 0.8144 |
| Creatinine (μg/L) | 72.1 ± 34.9 | 74.9 ± 35.3 | 69.1 ± 34.3 | 0.1483 |
| Creatinine-adjusted BPA at 4 years of age (μg/g creatinine) | 4.9 ± 10.8 | 4.3 ± 3.6 | 5.5 ± 15.3 | 0.3366 |
| K-SCQ- Total | 4.3 ± 3.1 | 5.0 ± 3.2 | 3.6 ± 2.7 | 0.0001 |
| K-SCQ- Social interaction | 1.1 ± 1.2 | 1.2 ± 1.3 | 0.9 ± 1.0 | 0.0083 |
| K-SCQ- Communication | 1.7 ± 1.4 | 1.8 ± 1.4 | 1.6 ± 1.3 | 0.0956 |
| K-SCQ- Behavior Patterns | 1.4 ± 1.7 | 1.7 ± 1.7 | 1.1 ± 1.5 | 0.0014 |
Abbreviations: SD standard deviation, BPA bisphenol A, K-SCQ Korean version of the Social Communication Questionnaire