Interrelationships between Growth Trajectory, Pubertal Development and Childhood Atopic Diseases/Symptoms in a Longitudinal Cohort Study

Background: Given the current obesity pandemic, it is essential to determine whether elevated adiposity in childhood, adolescence, or young adulthood contributes independently to the risk of disease. Child growth is dynamic. Studies evaluating the potential heterogeneity in the development of adiposity during childhood through adolescence are needed to describe the normative and atypical patterns that may increase the risk of early puberty development and atopic disease/symptoms. No study has ever explored the relationships between growth trajectory and pubertal development or the occurrences of atopic disease/symptoms. Objectives: We aim to (1) model different developmental paths during childhood and adolescence and to identify early risk factors associated with different paths; (2) determine the influence of different growth pattern subgroups on early pubertal development; (3) investigate whether types of growth trajectory from age 6 to 18 affect the occurrence of atopic diseases/symptoms; (4) assess the associations of pubertal stages and transitions through puberty with the prevalence, incidence, and remission rates of atopic diseases/symptoms during adolescence. Methods: In 2007 and 2010, we conducted a nationwide “Taiwan Children Health Study (TCHS) ” and recruited 7,930 nine to thirteen year-old school children in 14 Taiwanese communities. We have performed annual follow ups survey for them in 2010-2013. In this four years of research proposal, we plan to prospectively perform annual follow-up survey on questionnaires, obesity measurements, and pulmonary function tests for these children from 2015-2018. Retrospectively, we also plan to contact elementary school nurses of our participants to retrieve body weight and height (grade 1 to 6) from elementary school health record of our participants. We will use latent growth mixture model (LGMM) to identify the distinctive adiposity trajectory from age 6 to age 18, and perform several tests to judge model adequacy. Furthermore, we will determine whether different growth trajectories of adiposity predict childhood atopic disease/symptoms or puberty development by using discrete time hazard model (DTHM). We will also use structural equation model (SEM) to explore the mechanisms between growth trajectory, pubertal development and atopic disease/symptoms. Anticipated results: By this four-year longitudinal follow ups study, we will achieve the following research goals: 1. To build up optimal growth trajectory subgroups of different adiposity measurement from childhood to adolescence for future disease risk assessment. 2. To discover possible perinatal factors in predicting the different growth patterns in future childhood. 3. To identify the mean age of menarche and define early menarche among Taiwanese girls. We also aim to define early pubertal development for boys in Taiwan. 4. To examine the influence of different growth patterns on early or late pubertal development and to discuss the gender difference in the above relationships. 5. To compare the predictability of incident or remission of atopic disease/symptoms during childhood and adolescence by using different growth trajectory subgroups. 6. To explore the mechanisms between dynamic adiposity growth trajectory, pubertal development and atopic disease/symptoms.