24-h movement behaviors from infancy to preschool: cross-sectional and longitudinal relationships with body composition and bone health.

ABSTRACT: BACKGROUND:New physical activity guidelines for children address all movement behaviors across the 24-h?day (physical activity, sedentary behavior, sleep), but how each component relates to body composition when adjusted for the compositional nature of 24-h data is uncertain. AIMS:To i) describe 24-h movement behaviors from 1 to 5?years of age, ii) determine cross-sectional relationships with body mass index (BMI) z-score, iii) determine whether movement behaviors from 1 to 5?years of age predict body composition and bone health at 5?years. METHODS:24-h accelerometry data were collected in 380 children over 5-7?days at 1, 2, 3.5 and 5?years of age to determine the proportion of the day spent: sedentary (including wake after sleep onset), in light (LPA) and moderate-to-vigorous physical activity (MVPA), and asleep (including naps). BMI was determined at each age and a dual-energy x-ray absorptiometry (DXA) scan measured fat mass, bone mineral content (BMC) and bone mineral density (BMD) at 5?years of age. 24-h movement data were transformed into isometric log-ratio co-ordinates for multivariable regression analysis and effect sizes back-transformed. RESULTS:At age 1, children spent 49.6% of the 24-h?day asleep, 38.2% sedentary, 12.1% in LPA, and 0.1% in MVPA, with corresponding figures of 44.4, 33.8, 19.8 and 1.9% at 5?years of age. Compositional time use was only related significantly to BMI z-score at 3.5?years in cross-sectional analyses. A 10% increase in mean sleep time (65?min) was associated with a lower BMI z-score (estimated difference, -?0.25; 95% CI, -?0.42 to -?0.08), whereas greater time spent sedentary (10%, 47?min) or in LPA (10%, 29?min) were associated with higher BMI z-scores (0.12 and 0.08 respectively, both p?

SUBMITTER: Taylor RW 

PROVIDER: S-EPMC6260686 | biostudies-literature | 2018 Nov

REPOSITORIES: biostudies-literature