title: Obesity and the occurrence of bronchitis in adolescents.
abstract: OBJECTIVE
  Previous studies have shown that an elevated BMI was associated with higher risks of bronchitis among children. The magnitude of how increase in BMI influencing the risk of incident bronchitis remained unexplored. The objective of this study is to assess the association between BMI and the incidence of bronchitis in the Taiwan Children Health Study.
  
  
  METHODS
  A school-based prospective cohort study.
  
  
  METHODS
  We conducted a population-based prospective cohort study among seventh-grade school children in 14 Taiwanese communities. A total of 3,634 adolescents completed follow-up questionnaire in 2009. Associations between BMI and incident bronchitis were analyzed by multiple Poisson regression models, taking overdispersion into account.
  
  
  RESULTS
  Among eligible cohort participants without bronchitis at study entry, the proportion of overweight and obesity were 32.1% and 17.9%. Overweight was 40.7% and obesity was 27.7% among those with incident bronchitis. The BMI percentile categories showed significant increasing trends for bronchitis in total eligible children and in girls (P for trend <0.001). Overweight and obesity were both associated with increased risks of incident bronchitis. This association was significant in girls only while stratified by gender.
  
  
  CONCLUSIONS
  Our data showed that the BMI percentile and weight status were associated with higher risks of incident bronchitis in adolescents, especially in girls.
authors.affiliation: Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, Taipei, Taiwan. leolee@ntu.edu.tw
authors.forename: Yungling L
authors.initials: YL
authors.lastname: Lee
authors.forename: Yang-Ching
authors.initials: YC
authors.lastname: Chen
authors.forename: Yu-An
authors.initials: YA
authors.lastname: Chen
mesh_terms: D000293:Adolescent; D015992:Body Mass Index; D001991:Bronchitis / Q000209:etiology*; D002648:Child; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D009765:Obesity / Q000150:complications*; D050177:Overweight / Q000150:complications*; D016012:Poisson Distribution; D011446:Prospective Studies; D012307:Risk Factors; D011795:Surveys and Questionnaires; D013624:Taiwan