TABLE 3.
Multilevel longitudinal growth models from birth to 10 y in IS infants, randomized to iron supplementation or usual nutrition at 6 mo1
| Weight |
Length/height |
|||||
|---|---|---|---|---|---|---|
| Characteristics | Before supplementation birth–6 mo | During supplementation 6–12 mo | After supplementation 1–10 y | Before supplementation birth–6 mo | During supplementation 6–12 mo | After supplementation 1–10 y |
| Intercept | ||||||
| Weight, kg, or length, cm | 5.98 (5.83, 6.13) | 8.99 (8.76, 9.22) | 36.1 (34.1, 38.2) | 58.8 (58.3, 59.2) | 70.2 (69.6, 70.7) | 142.2 (140.0, 144.4) |
| Iron | −0.06 (−0.25, 0.13) | 0.06 (−0.26, 0.38) | 0.5 (−2.1, 3.0) | 0.1 (−0.4, 0.7) | 0.4 (−0.3, 1.1) | −0.7 (−3.5, 2.1) |
| Slope | ||||||
| Growth rate, kg or cm/mo | 0.70 (0.67, 0.73) | 0.30 (0.27, 0.33) | 0.2 (0.15, 0.25) | 2.5 (2.4, 2.6) | 1.31 (1.25, 1.36) | 0.62 (0.59, 0.64) |
| Slope × iron | 0.02 (−0.03, 0.06) | 0.02 (−0.01, 0.06) | 0.01 (−0.01, 0.04) | 0.1 (0.05, 0.2)* | 0.0 (−0.1, 0.1) | 0.0 (−0.01, 0.01) |
| Quadratic | ||||||
| Deceleration, kg2 or cm2/mo | −0.03 (−0.04, −0.025) | −0.03 (−0.04, −0.025) | — | −0.1 (−0.15, 0.05) | −0.1 (−0.15, 0.05) | — |
| Quadratic × iron | 0.0 (−0.01, 0.01) | 0.0 (−0.01, 0.01) | — | 0.0 (−0.01, 0.01) | 0.0 (−0.01, 0.01) | — |
| Covariates2 | ||||||
| SES index | 0.01 (0.00, 0.03)* | 0.01 (0.00, 0.03)* | −0.1 (−0.2, 0.0) | 0.0 (0.0, 0.1) | 0.03 (0.0, 0.1) | −0.1 (−0.2, 0.1) |
| Male | 0.37 (0.23, 0.51)** | 0.37 (0.23, 0.51)** | −0.7 (−2.2, 0.8) | 1.4 (0.9, 1.9)** | 1.4 (0.9, 1.9)** | 0.3 (−1.2, 1.9) |
| Birth weight |
— |
— |
1.7 (−0.2, 3.5) |
— |
— |
0.3 (−0.2, 0.8) |
1
Values are estimate (95% CI) at 3 mo, 9 mo, and 10 y, n = 56 (iron-supplemented) and 62 (usual nutrition group). *SES related to weight at 3 and 9 mo in the model, P < 0.05. **Male sex associated with higher weight and height at 3 and 9 mo in the models, P < 0.0001.
2
Covariates were included for estimation of weight or length.