title: Natural progression of childhood asthma symptoms and strong influence of sex and puberty.
abstract: BACKGROUND
  Asthma prevalence, onset, remission and relapse, and healthcare use have been intensively studied. However, asthma symptom progression through childhood and adolescence has not been well studied, in part due to the challenges in obtaining consistent and robust long-term follow-up data on a large series of subjects with asthma.
  
  
  OBJECTIVE
  To use the asthma diary symptom data of the Childhood Asthma Management Program placebo group (5 yr, 418 subjects, and total 564,518 records) to establish sex-specific high-resolution time courses of the natural progression of asthma symptoms through childhood and adolescence.
  
  
  METHODS
  We used the asthma diary symptom code as a measure of daily disease severity. Annual records of Tanner stage were used to determine the influence of puberty on severity. A data alignment technique was used to derive 13-year time courses of mean symptoms and mean Tanner stage.
  
  
  RESULTS
  Data analyses showed three age- and sex-related phases of asthma symptom progression: Phase 1 (ages 5 and 6 yr)-greater severity in boys; Phase 2 (ages 7 to 9 yr)-no sex difference in severity; and Phase 3 (age 10-17 yr)-greater severity in girls. The continuous decline of symptoms in both sexes stops abruptly at the onset of puberty.
  
  
  CONCLUSIONS
  The severity of asthma symptoms varies through childhood and adolescence, and patterns differ by sex. Puberty has a strong influence on symptom progression in both sexes. Progression of symptoms is a distinct aspect of asthma epidemiology.
authors.affiliation: 1 Division of Research and Development, SoverST, LLC, Rockville, Maryland.
authors.forename: Liang
authors.initials: L
authors.lastname: Fu
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Freishtat
authors.forename: Heather
authors.initials: H
authors.lastname: Gordish-Dressman
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Teach
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Resca
authors.forename: Eric P
authors.initials: EP
authors.lastname: Hoffman
authors.forename: Zuyi
authors.initials: Z
authors.lastname: Wang
mesh_terms: D000293:Adolescent; D018927:Anti-Asthmatic Agents / Q000627:therapeutic use; D001249:Asthma / Q000175:diagnosis / Q000188:drug therapy / Q000453:epidemiology*; D002648:Child; D002675:Child, Preschool; D018450:Disease Progression; D005260:Female; D006801:Humans; D008297:Male; D009017:Morbidity / Q000639:trends; D011627:Puberty; D012307:Risk Factors; D012737:Sex Factors; D012741:Sexual Maturation; D014481:United States / Q000453:epidemiology
chemical_list: D018927:Anti-Asthmatic Agents
keywords: epidemiology; sex difference; sex dominance