Introduction: Obesity is one of the most prevalent chronic diseases in childhood, being an important public health issue. Excess weight has been associated with autonomic dysfunction but the evidence in children is scarce. Therefore, this study aimed to assess the effect of overweight and obesity on the autonomic nervous system activity in children.
Methods: Data were collected from a cross sectional study including 916 children (7 to 12 years), from 20 primary schools in Porto, Portugal. Anthropometric measurements and bioelectrical impedance analysis were performed to assess body mass index (BMI) and characterize body composition - body fat percentage, body fat mass and total body water. BMI was classified according to age- and sex-specific percentiles defined by the World Health Organization, the US Centers for Disease Control and Prevention and the International Obesity Task Force. Pupillometry was performed to evaluate autonomic activity. Mann-Whitney, the chi-square, and Kruskall-Wallis tests were used as appropriate.
Results: Final analysis included 858 children, 50.6% boys, with a prevalence of obesity ranging between 7.5% and 16.2% according to the International Obesity Task Force and percentage of body fat criteria, respectively. The average dilation velocity was significantly higher among children with obesity, regardless of BMI criteria.
Conclusions: Our results suggest that obesity in children is associated with a dysautonomia in autonomic nervous system, namely with changes in sympathetic activity. Moreover, these findings provide support for the role of the autonomic nervous system in the interaction between lifestyle, diet and the BMI in children.
Beatriz Gonçalves Teixeira