AbstractsEconomics

Abstract

Introduction: The increase in the prevalence of obesity, asthma, and rhinitis in childhood suggests a link between them. Socio-demographic and early life risk factors, sedentary lifestyle, diet and tobacco exposure, among other factors, could be responsible for the increase in the number of obese asthmatics. There are two main phenotypes of obese asthmatics described so far and one includes children. The existence of obesity-related asthma and rhinitis means that obese children with asthma or rhinitis are not only different from healthy children, but also from normal-weight children with these diseases. Little is known about the effects of the risk factors on the different asthma phenotypes. Objectives: To investigate how common environmental, family and socioeconomic risk factors for obesity, asthma and rhinitis modulate the association between these diseases and to study whether birth weight (BW) values differ between overweight children with asthma/rhinitis and children with asthma/rhinitis and normal weight. Methods: This cross-sectional study was done in a sample of 1043 children 6-8 years old from the Coimbra district. Data on asthma (A), rhinitis (R) and environmental and family factors were obtained using the ISAAC (The International Study of Asthma and Allergies in Childhood) questionnaires. Obesity indicators were calculated: Body Mass Index (BMI); BMI z-score based on the World Health Organization’s (WHO) methodology; Waist to Height Ratio (WHtR) and the body fat percentage (%BF). Obesity (OB) and overweight (O) were defined using the WHO cut-off points. The cut-off point of WHtR=0.5 was used to define abdominal obesity (AOB). %BF values were categorized as normal, overfat (OF) and high fat (HF) using age and gender-specific percentiles. The risk factors studied were: BW; breastfeeding (BFD) ever, total (TBFD) and exclusive (EBFD); tobacco exposure in early life and in childhood; dietary patterns; vigorous physical activity (VPA); television (TV) watching; heavy truck traffic (HTT); degree of urbanization of the residential area and socioeconomic status (SES). Chi 2 tests were applied to calculate the prevalences of studied diseases. Logistic regressions were used to study the association between OB, A, and R with risk factors. Student’s T-test and one-way ANOVA means comparisons were applied to compare means. Logistic regressions were used to study the association of OB with A/R and the role of risk factors in these associations. One-way ANOVA was performed to compare means of BW between: 1. children with (+) A, wheeze (W) or R (A+/W+/R+) and O+/OF+; 2. children A+/W+/R+ but without (-) O or OF (O-/OF-); 3. O+/OF+ but A-/W-/R- and 4. children A-/W-/R- and O-/OF-. Results: Of all studied children, 23.3% were O, 10.8% OB. Factors related to a significant increase in OB risk were: high BW; being a girl; saturated fat diet; lower SES; never having been BFD or EBFD; anyone smoking at home; current maternal smoking (MS); MS>10cigarettes (cig.) /day and watching TV≥3h/day. Factors significantly increasing the…