title: Passive smoking induces leukotriene production in children: influence of asthma.
abstract: BACKGROUND
  Passive smoking is associated with poor asthma control in children, but the mechanism is unknown. Leukotrienes are involved in the asthma pathogenesis and their synthesis is increased in adult subjects who actively smoke.
  
  
  OBJECTIVE
  To evaluate whether passive smoking, as assessed by urinary cotinine levels, increases leukotriene production in children with or without asthma.
  
  
  METHODS
  This was a prospective, cross-sectional study in which children with stable intermittent asthma (without exacerbation) and healthy control children were studied through spirometry and urinary concentrations of cotinine and leukotriene E(4) (LTE(4)). Both groups were balanced to include children with and without passive smoking.
  
  
  RESULTS
  Ninety children (49 with asthma and 41 controls, 54.4% females) aged 9 years (range, 5-13 years) were studied. Urinary LTE(4) concentrations were progressively higher as cotinine levels increased (r(S) = 0.23, p = .03). LTE(4) also correlated with body mass index (BMI) (r(S) = 0.30, p = .004), and multiple regression analysis revealed that BMI was even more influential than cotinine for determining LTE(4) levels. LTE(4) concentrations were unrelated with gender, age, or spirometry. In turn, cotinine inversely correlated with forced expiratory volume in one second (FEV(1)) (r(S) = -0.22, p = .04) and forced vital capacity (FVC) (r(S) = -0.25, p = .02), but when analyzed by groups, these relationships were statistically significant only in children with asthma.
  
  
  CONCLUSIONS
  Exposure to environmental tobacco smoke, as assessed by urinary cotinine levels, was associated with an increased urinary concentration of LTE(4), although BMI exerted more influence in determining its concentration. Urinary cotinine was associated with decreased lung function, mainly in children with asthma.
authors: Departamento de Neumopediatría, Hospital General Gaudencio González Garza, Centro Médico Nacional La Raza, Instituto Mexicano del Seguro Social, Mexico DF, Mexico.
authors: Elizabeth
authors: E
authors: Hernández-Alvídrez
authors: Georgina
authors: G
authors: Alba-Reyes
authors: Bernardo C
authors: BC
authors: Muñoz-Cedillo
authors: José Luis
authors: JL
authors: Arreola-Ramírez
authors: María Elena Yuriko
authors: ME
authors: Furuya
authors: Martín
authors: M
authors: Becerril-Ángeles
authors: Mario H
authors: MH
authors: Vargas
mesh_terms: D000293:Adolescent; D001249:Asthma / Q000378:metabolism* / Q000652:urine; D002648:Child; D002675:Child, Preschool; D003367:Cotinine / Q000652:urine; D003430:Cross-Sectional Studies; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D017999:Leukotriene E4 / Q000096:biosynthesis* / Q000652:urine; D008297:Male; D015999:Multivariate Analysis; D011446:Prospective Studies; D012044:Regression Analysis; D014028:Tobacco Smoke Pollution / Q000009:adverse effects*; D014797:Vital Capacity
chemical_list: D014028:Tobacco Smoke Pollution; D017999:Leukotriene E4; D003367:Cotinine