Relação entre a composição das 24 horas do movimento e a variabilidade da frequência cardíaca em pré-escolares

Abstract

Associative studies have been linking physical activity (PA), sedentary behavior (SB) and sleep behaviors to autonomic activity in different populations. However, the age group of preschoolers has still been little explored. A new perspective of analysis is emerging in the health area, taking into account the composition of these behaviors over the 24 hours. Thus, the objective of this study was to associate the composition of movement behaviors over 24 hours and the heart rate variability (HRV) in preschool children in the city of João Pessoa-PB. For this, 123 children aged 3-5 years (4.52 ± 0.25 years, 62 girls) students from two Reference Centers in Early Childhood Education - CREI’s in João Pessoa were evaluated. PA and SB were measured using an accelerometer (wGT3x) and analyzed according to the intensities (mild, moderate, vigorous and sedentary behavior). Sleep time was determined from an interview with parents or guardians. HRV was measured using a chest strap (Firstbeat ®, Finland) for 10 minutes, the last five minutes being used for analysis. In addition, weight and height were measured, according to standard procedures, and the body mass index was calculated. A linear regression was performed using the compositional data, through the R Core Team (version 3.6.1, 2019). The descriptive results showed that there are significant differences for SC between children aged 3-4 and 4-5 years (p<0,05). The behaviors that showed the lowest codependency relationship were MVPA and CS. Only the RMSSD index was significantly associated with the 24-hour movement (p <0.05). Thus, we concluded that the daily composition in movement behaviors was able to predict parasympathetic activity in preschool children.