title: Genetic variation of IL13 as a risk factor of reduced lung function in children and adolescents: a cross-sectional population-based study in Korea.
abstract: BACKGROUND
  Previous investigations have suggested that genetic variations are associated with reduced lung function in early childhood. This study was conducted to evaluate the association between IL13+2044G-->A, the functionally relevant single nucleotide polymorphism (SNP) in the gene coding IL13, and lung function in early childhood.
  
  
  METHODS
  A total of 1900 subjects aged 10-18 years living in Korea, were randomly recruited. Lung function test and methacholine bronchial provocation test were performed. Multiple regression analysis adjusting for sex, age, height, atopy, and history of passive smoking was done to evaluate effect of IL13+2044G-->A on lung function.
  
  
  RESULTS
  Mean (+/-SD) forced expiratory volume in 1 s (FEV(1)) was 2.66 L (+/-0.60) in subjects with the AA or AG genotype (n=982) and 2.75 L (+/-0.57) in subjects with the GG genotype (n=918). IL13+2044G-->A showed a significant association with FEV(1) [in the minor allele dominant model (GG vs. AG+AA), P<0.001]. Interestingly, the association between FEV(1) and IL13+2044G-->A remained still significant in subgroup analysis according to the presence of AHR (P<0.001 in subjects without AHR and P=0.002 in subjects with AHR). Moreover, FEV(1)/FVC (forced vital capacity) ratio also showed a significant association with IL13+2044G-->A in both groups (P<0.001 in subjects without AHR and P<0.001 in subjects with AHR). This cross-sectional study demonstrates that IL13+2044G-->A is significantly associated with a reduced lung function in Korean children and adolescents.
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea.
authors.forename: Heung-Woo
authors.initials: HW
authors.lastname: Park
authors.forename: Jong-Eun
authors.initials: JE
authors.lastname: Lee
authors.forename: Se-Hoon
authors.initials: SH
authors.lastname: Kim
authors.forename: Yoon-Keun
authors.initials: YK
authors.lastname: Kim
authors.forename: Kyung-Up
authors.initials: KU
authors.lastname: Min
authors.forename: You-Young
authors.initials: YY
authors.lastname: Kim
authors.forename: Sang-Heon
authors.initials: SH
authors.lastname: Cho
mesh_terms: D000293:Adolescent; D001249:Asthma / Q000235:genetics* / Q000503:physiopathology; D001985:Bronchial Provocation Tests / Q000379:methods; D002648:Child; D003430:Cross-Sectional Studies; D005260:Female; D005541:Forced Expiratory Volume / Q000235:genetics* / Q000502:physiology; D014644:Genetic Variation / Q000235:genetics; D005838:Genotype; D006801:Humans; D018793:Interleukin-13 / Q000235:genetics* / Q000502:physiology; D007723:Korea; D008297:Male; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D012307:Risk Factors; D014028:Tobacco Smoke Pollution / Q000009:adverse effects; D014797:Vital Capacity / Q000235:genetics* / Q000502:physiology
chemical_list: D018793:Interleukin-13; D014028:Tobacco Smoke Pollution