Table 5.
Predictive and concurrent relationships between sleep and activity components at 1, 2, 3.5 and 5 years of age and fat-free mass index at 5 yearsa
| Age (years) | Mean fat free mass index (SD) at 5 years of age, kg/m2 | Component | Regression coefficientb (SE) | p-value | 10% difference in minutes | Estimated difference (95% CI) in % body fat with a 10% increase in component | Estimated difference (95% CI) in % body fat with a 10% decrease in component |
|---|---|---|---|---|---|---|---|
| 1 (n = 229) | 12.7 (0.8) | Sleepc | − 0.46 (0.32) | 0.144 | 71 | −0.079 (− 0.184, 0.026) | 0.079 (− 0.027, 0.185) |
| Sedentaryd | 0.27 (0.32) | 0.393 | 56 | 0.038 (−0.049, 0.124) | −0.039 (− 0.129, 0.050) | ||
| LPA | 0.16 (0.15) | 0.278 | 18 | 0.015 (−0.012, 0.043) | −0.017 (− 0.046, 0.013) | ||
| MVPA | 0.03 (0.04) | 0.488 | 0.1 | 0.003 (−0.005, 0.010) | −0.003 (− 0.011, 0.005) | ||
| 2 (n = 158) | 12.8 (0.8) | Sleep | −0.32 (0.35) | 0.365 | 69 | −0.053 (− 0.166, 0.061) | 0.053 (− 0.061, 0.168) |
| Sedentary | 0.60 (0.32) | 0.065 | 46 | 0.075 (−0.004, 0.154) | −0.079 (− 0.162, 0.004) | ||
| LPA | −0.37 (0.32) | 0.244 | 28 | −0.039 (− 0.104, 0.026) | 0.042 (− 0.028, 0.112) | ||
| MVPA | 0.09 (0.08) | 0.234 | 0.6 | 0.008 (−0.005, 0.020) | −0.008 (− 0.022, 0.005) | ||
| 3.5 (n = 178) | 12.8 (0.8) | Sleep | −2.19 (0.53) | < 0.001 | 65 | −0.346 (− 0.509, − 0.183) | 0.352 (0.186, 0.518) |
| Sedentary | 0.87 (0.43) | 0.046 | 47 | 0.110 (0.003, 0.217) | −0.116 (− 0.229, − 0.003) | ||
| LPA | 1.26 (0.31) | < 0.001 | 29 | 0.132 (0.070, 0.195) | −0.143 (− 0.210, − 0.075) | ||
| MVPA | 0.06 (0.12) | 0.641 | 2 | 0.005 (− 0.015, 0.024) | − 0.005 (− 0.027, 0.017) | ||
| 5 (n = 213) | 12.7 (0.8) | Sleep | −0.82 (0.55) | 0.134 | 64 | −0.127 (− 0.292, 0.039) | 0.129 (− 0.039, 0.298) |
| Sedentary | 0.17 (0.41) | 0.673 | 49 | 0.022 (−0.080, 0.124) | −0.023 (− 0.131, 0.084) | ||
| LPA | 0.48 (0.30) | 0.116 | 28 | 0.050 (− 0.012, 0.111) | −0.054 (− 0.120, 0.013) | ||
| MVPA | 0.17 (0.13) | 0.170 | 3 | 0.015 (− 0.006, 0.035) | −0.016 (− 0.039, 0.007) |
LPA is light physical activity, MVPA is moderate-to-vigorous physical activity
aAdjusted for randomised group, sex, primiparous, maternal education, household deprivation, ethnicity and maternal BMI. Analyses at 1 year of age further adjusted for whether the child was walking unaided or not walking
bCoefficient for the first isometric log ratio (ilr) co-ordinate, which is proportional to the log ratio of the behavior and the geometric mean of the remaining behaviors; adjusted for remaining ilr co-ordinates
cAll sleep estimates include naps where relevant
dAll sedentary estimates include wake after sleep onset
Bolded values indicate P < 0.05