Longitudinal associations of leptin and adiponectin with heart rate variability in children

For early prevention of cardiovascular disease, early detection and risk factor insights are necessary. The autonomic balance reflects cardiovascular risk and can be measured by heart rate variability (HRV). Therefore, our purpose is to examine associations between HRV and the energy-related biomarkers leptin and adiponectin in children. Participants of this study were Belgian children recruited for the longitudinal ChiBS study (year 2010-2012). HRV was measured and fasting blood samples were taken in 249 children at baseline (4.4-11.0 y) and 223 children at follow-up (6.7-12.2 y). Cross-sectional and longitudinal linear regression analyses were separated by sex and adjusted for age, socio-economic status, body fat%, negative emotions, puberty, and mean heart rate. Leptin was a negative cross-sectional and longitudinal predictor of parasympathetic activity in boys; while leptin in girls was cross-sectionally associated with higher LF and LF/HF suggesting sympathetic predominance. Adiponectin was a negative cross-sectional and longitudinal predictor of parasympathetic activity in boys; but when adjusting for mean heart rate, this effect disappeared and adiponectin was a positive cross-sectional and longitudinal predictor of parasympathetic activity in girls. These results stress the importance of considering sex differences and adjustment for heart rate in testing HRV predictors. Leptin seemed disadvantageous for the autonomic balance, while adiponectin seemed advantageous for the autonomic balance in girls only. More research is needed to see whether leptin and adiponectin are interesting in cardiovascular screening/prevention or in determining the cardiovascular gain during weight loss follow-up

The influence of parenting style on health related behavior of children : findings from the ChiBS study

Objective: Exploring associations between parenting behavior and children's health related behavior including physical activity, sedentary behavior, diet and sleep. Methods: We recruited 288 parents and their children (6-12y old). Children's weight and height were measured. Fat percentage was determined by air displacement plethysmography. Parents reported socio-demographic data, sleep information, physical activity and sedentary behavior of their child and completed the Comprehensive General Parenting Questionnaire (CGPQ) and a Food Frequency Questionnaire. Children completed the Dutch Eating Behavior Questionnaire. Associations between parenting behavior (CGPQ) and children's health related behavior were assessed with univariate and multiple regression analyses. Results: A small positive correlation was found between sweet food consumption frequency and "coercive control" (r = 0.139) and a small negative correlation between fruit and vegetables consumption frequency and "overprotection" (r = -0.151). Children consumed more frequently soft drinks when their parents scored lower on "structure" (r = -0.124) and higher on "overprotection" (r = 0.123); for the light soft drinks separately, a small positive correlation with "behavioral control" was found (r = 0.172). A small negative correlation was found between "emotional eating" and "structure" (r = -0.172) as well as "behavioral control" (r = -0.166). "Coercive control" was negatively correlated with the child's sleep duration (r = -0.171). After correction for confounding factors, the following significant associations were found: (1) a small negative association between "structure" and soft drinks consumption (beta = -0.17 for all soft drinks and -0.22 for light soft drinks), (2) a small positive association between "behavioral control" and light soft drinks (beta = 0.34), (3) a small positive association of "nurturance" and "coercive control" with sedentary behavior (beta = 0.16 for both parent constructs) and (4) a small negative association between the parenting construct "coercive control" and sleep duration (beta = -0.23). Conclusion: The significant but small associations between parenting constructs and the investigated variables suggest that different aspects of parenting style play an important role in the genesis of the health related behavior of children. Overall, our findings suggest that health professionals should encourage parents to apply the more positive parenting constructs i.e., more "structure" and "behavioral control", and less "coercive control". They could, for instance, supervise and manage their child's activities and help their child to achieve certain goals

Children’s body composition and stress, the ChiBS study : aims, design, methods, population and participation characteristics

BACKGROUND: The last decades, the prevalence of childhood obesity has increased. Apart from other lifestyle factors, the effect of chronic psychosocial stress on the development of obesity has been recognized. However, more research is needed into the influence of chronic stress on appetite regulation, energy balance and body composition, as well as on the interaction with physical activity/sedentary behavior, diet and sleep in children. In this regard, the ChiBS study (Children’s Body composition and Stress) was designed at the Ghent University. Within this paper, we describe the aims, design, methods, participation and population characteristics of the ChiBS study. METHODS: The influence of chronic stress on changes in body composition is investigated over a two-year follow-up period (February-June 2010, 2011 and 2012) in primary-school children between 6 and 12 years old in the city Aalter (Flanders, Belgium). Stress is measured by child- and parent-reported stress-questionnaires, as well as by objective stress biomarkers (serum, salivary and hair cortisol) and heart rate variability. Body composition is evaluated using basic anthropometric measurements and air displacement plethysmography. Additional information on socio-economic status, medical history, physical activity, dietary intake and sleep are obtained by questionnaires, and physical activity by accelerometers. RESULTS: The participation percentage was 68.7% (N = 523/761), with 71.3% of the children willing to participate in the first follow-up survey. Drop-out proportions were highest for serum sampling (12.1%), salivary sampling (8.3%) and heart rate variability measurements (7.4%). DISCUSSION: The ChiBS project is unique in its setting: its standardized and longitudinal approach provides valuable data and new insights into the relationship between stress and changes in body composition in a large cohort of young children. In addition, this study allows an in-depth investigation of the validity of the different methods that were used to assess stress levels in children