Effect of obesity and depression on autonomic nervous system reactivity and pulmonary function in asthmatic children

The goal of this interdisciplinary retrospective analysis study, bridging the fields of Neuroscience, Public Health and Biomedical Informatics, is to gain insight into 1) if and how obesity and depression affect asthmatic children's autonomic reactivity and pulmonary function, and 2) if and how ontological methods refine the neurophysiological relevance of depression assessment instruments and thus enhance the analyses on the inter-relations of depression, obesity and asthma. The current study investigated five hypotheses. Hypothesis 1: Obesity (BMI percentile) and child depression (CDI), will be associated with a decrease in pulmonary function (↓FEV1 and ↑Rint ) in asthmatic children; these factors will interact with one another to enhance the negative effect on pulmonary function. Hypothesis 2: Obesity (BMI percentile) and child depression (CDI), will be positively associated with autonomic dysregulation (in the direction of Vagal Bias) in asthmatic children. Hypothesis 3: Vagal bias will be associated with decrease in pulmonary function in obese asthmatic children. Hypothesis 4: Adjusting child depression scoring by excluding anxiety components will improve the ability to predict the effect of depression on pulmonary function autonomic reactivity. Hypothesis 5: Ontologically extrapolated child depression scores will improve the ability to predict the effect of depression on pulmonary function and increase the regression coefficient for the effect of depression on autonomic reactivity. Redirected Hypothesis 5: Both State and Trait Anxiety will predict lower pulmonary function and greater Vagal Bias.;To conduct this research study, selected data taken from the Child and Family Asthma Study Center Comprehensive Database were analyzed. The database was established from the study of 304 children and adolescents, aged 7-17, who presented to the emergency department of Women and Children's Hospital of Buffalo from 2002 to 2007 for treatment of asthma exacerbation and who were recruited to participate in a laboratory based study of stress and asthma. Depression and anxiety symptoms were assessed by self-reported questionnaires designed for children and adolescents. Measures of vagal and sympathetic activity in the cardio-respiratory system were obtained by continuous monitoring of respiratory sinus arrhythmia and pre-ejection period, respectively; these physiological measures were collected continuously from asthmatic children during a video presentation intended to induce emotional arousal. The pulmonary function measures were obtained before, during and after the laboratory stress protocols.;Results from standard regression indicated that obesity did not predict lower pulmonary function and autonomic dysregulation (Vagal Bias) in asthmatic children (Hypothesis 1 and 2). However, in obese asthmatic children depression did predict vagal bias and decreased pulmonary function (Hypothesis 1 and 2), and vagal bias predicted decreased pulmonary function (Hypothesis 3). Separating depression symptoms from anxiety symptoms did not change the effect shown above (Hypothesis 4). Finally, anxiety alone was found to have a negative effect on pulmonary function in the obese asthmatic children (Hypothesis 5).