Exploring Associations Of 24-hour Movement Behaviors With Neurodevelopmental Markers In Mexican Preschoolers

Daily time spent in physical activity, sedentary behavior, and sleep (24-hour movement behaviors) is associated to child health outcomes. However, most evidence stems from high-income countries, predominantly relies on regression approaches treating each movement behavior as independent, and the differential effects of specific physical activity intensities remains largely unexplored. PURPOSE: To examine the association of intensity-specific physical activity, sedentary behavior, and sleep, with neurodevelopment in Mexican preschoolers, using methods that account for the co-dependence of 24-hour movement behaviors. METHODS: 64 children (age = 4.36 ± 0.42 years, 48% female) in the Mexican pilot of the International Study of Movement Behaviors in the Early Years (SUNRISE) wore an accelerometer for ten 24-hour periods to assess time in light, moderate, and vigorous physical activity; sedentary behavior; and sleep. Compositional isotemporal substitution models estimated the effects of reallocating 10 minutes to each behavior from all other behaviors on markers of cognitive and motor performance. This method accounts for the fact time in one behavior cannot exist without taking time from the others. Models adjusted for age, sex, rurality, and household socioeconomic status. RESULTS: Reallocating 10 minutes from any behavior to vigorous physical activity was associated with a 0.39 z-score increase in working memory (95%CI: 0.03 - 0.75), and a 0.41 z-score increase in postural stability (95%CI: 0.08 - 0.73). Reallocating 10 minutes to sedentary time was associated with a 0.04 z-score increase in hand dexterity (95%CI: 0.004 - 0.67). Reallocating 10 minutes to moderate physical activity was associated with a 0.19 z-score decrease in gross locomotion (95%CI: -0.37 - -0.018). CONCLUSION: This exploratory analysis found significant associations between 24-hr movement behaviors and cognitive and motor development markers in Mexican preschoolers. Findings suggest vigorous activity may be important for cognitive development. More robust studies are needed to confirm the results, including elucidating possible benefits for fine motor skills of slightly increased time in sedentary behavior; and further exploring the role of moderate-intensity physical activity on gross motor skills in this population. Supported by: Fogarty International Center, USA NIH