Table 1.
Characteristics of the study subjects in China*
| Age | Birth | <1 year | 1–2 year | 2–3 year | 3–4 year | 4–6year | p value |
|---|---|---|---|---|---|---|---|
| Total visits | 133,954 | 663,452 | 167,125 | 113,415 | 38,739 | 12,726 | - |
| Number of subjects | 133,954 | 127,944 | 93,678 | 64,781 | 33,478 | 11,839 | - |
| Male | 64,630 (48.3) | 61,727 (48.3) | 48,446 (51.7) | 31,339 (48.4) | 17,175 (51.3) | 5,657 (47.8) | < 0.01 |
| Urban residence | 18,127 (13.5) | 17,411 (13.9) | 12,920 (14.1) | 8,696 (13.8) | 4,612 (14.2) | 2,311 (20.0) | < 0.01 |
| Highly educated mother† | 28,363 (23.0) | 27,501 (23.6) | 19,124 (22.7) | 12,006 (21.1) | 5,956 (20.9) | 1,707 (19.6) | < 0.01 |
| Preterm | 4,053 (3.3) | 3,972 (3.4) | 2,840 (3.4) | 1,932 (3.4) | 966 (3.4) | 285 (3.3) | 0.59 |
| Routinely working mother‡ | 25,720 (20.8) | 24,867 (21.3) | 17,927 (21.2) | 11,762 (20.7) | 6,137 (21.5) | 1,840 (21.1) | < 0.01 |
| Breast fed§ | 105,643 (84.6) | 107,544 (84.2) | 79,243 (84.8) | 55,916 (86.5) | 28,975 (86.8) | 10,216 (87.2) | < 0.01 |
| BMI mean level | 13.3 (1.4) | 14.3 (2.0) | 17.4 (1.4) | 16.3 (1.3) | 15.8 (1.2) | 15.4 (1.3) | < 0.01 |
| Underweight (BMI Z∫<-2) | 7,662 (5.7) | 10,939 (8.6) | 337 (0.4) | 298 (0.5) | 265 (0.8) | 133 (1.1) | < 0.01 |
| Overweight (BMI Z≥ 2) | 3,361 (2.5) | 2,196 (1.7) | 6,325 (6.8) | 2,858 (4.4) | 1,008 (3.0) | 239 (2.0) | < 0.01 |
| Obesity (BMI Z≥ 3) | 375 (0.3) | 322 (0.3) | 795 (0.9) | 367 (0.6) | 145 (0.4) | 47 (0.4) | < 0.01 |
*
Data were presented by mean (SD: standard deviation) or frequency (%) from Chi-square test and ANOVA.
†
Highly educated was defined by maternal education more than high school.
‡
Routine work included all work except for house work and temporary work.
§
Breast fed was defined by whole breast feeding before first 6 month.
∫
BMI-Z was calculated based on the 2006 WHO Growth Standard.