TABLE 2.
Characteristics of the study population (N = 3714)
| Boys (N = 1850) | Girls (N = 1864) | |||||
|---|---|---|---|---|---|---|
| Normal weight N = 1635 (88.4%) | Overweight N = 215 (11.6%) | Normal weight N = 1592 (85.4%) | Overweight N = 272 (14.6%) | |||
| Maternal age | Mean (SD) | 31.4 (5.1) | 29.3 (5.7)* | 31.5 (4.9) | 29.5 (5.9)* | |
| Maternal country of origin | European origin | N (%) | 1181 (72.2) | 89 (41.4)* | 1192 (74.9) | 117 (43.0)* |
| Other | N (%) | 454 (27.8) | 126 (58.6) | 400 (25.1) | 155 (57.0) | |
| Maternal socioeconomic status | Low | N (%) | 320 (19.7) | 82 (38.7)* | 264 (16.7) | 99 (37.2)* |
| Middle | N (%) | 575 (35.4) | 87 (41.0) | 602 (38.1) | 101 (38.0) | |
| High | N (%) | 731 (45.0) | 43 (20.3) | 716 (45.3) | 66 (24.8) | |
| Maternal weight status | Not overweight | N (%) | 1177 (78.0) | 106 (54.6)* | 1182 (79.3) | 123 (51.3)* |
| Overweight | N (%) | 332 (22.0) | 88 (45.4) | 309 (20.7) | 117 (48.7) | |
| Maternal parity | Nulliparous | N (%) | 878 (53.7) | 106 (49.3) | 869 (54.6) | 138 (50.7) |
| Multiparous | N (%) | 757 (46.3) | 109 (50.7) | 723 (45.4) | 134 (49.3) | |
| Maternal smoking during pregnancy | Yes | N (%) | 158 (9.7) | 30 (14.0)* | 149 (9.4) | 46 (16.9)* |
| No | N (%) | 1476 (90.3) | 185 (86.0) | 1443 (90.6) | 226(83.1) | |
| Gestational age at birth (days) | Mean (SD) | 279 (12) | 278 (13) | 279 (11) | 279 (11) | |
| Birth weight (grams) | Mean (SD) | 3548 (556) | 3630 (581)* | 3412 (515) | 3443 (542) | |
| BMI at age 5‐6 years | Mean (SD) | 15.5 (0.8) | 18.9 (1.6)* | 15.4 (0.9) | 19.0 (1.7)* | |
| Duration of exclusive breastfeedinga | None | N (%) | 276 (17.7) | 41 (20.3)* | 250 (16.4) | 57 (21.5)* |
| <1 months | N (%) | 125 (8.0) | 26 (12.9) | 124 (8.1) | 32 (12.1) | |
| 1–3 months | N (%) | 459 (29.4) | 69 (34.2) | 434 (28.5) | 67 (25.3) | |
| >3 months | N (%) | 699 (44.8) | 66 (32.7) | 714 (46.9) | 109 (41.1) | |
| Sleep (h)a | Mean (SD) | 10.5 (0.9) | 10.3 (1.1)* | 10. 5 (0.9) | 10.3 (1.1)* | |
| Screentime (h)a | Mean (SD) | 1.5 (1.1) | 1.9 (1.2)* | 1.3 (0.9) | 1.8 (1.2)* | |
| Member of sports club a | N (%) | 646 (53.6) | 66 (56.9) | 506 (44.0) | 91 (58.3)* | |
*
P < 0.05.
a
Measured in a subset of N = 3548 (breastfeeding) and N = 1309 (sleep, screen time, membership of sports club).