Study of Bronchial Inflammation in Adolescent Smokers With and Without Obesity
Condition: Obesity; Tobacco Smoking
MeSH terms: Obesity; Inflammation
Study type: Observational

Summary: 
      The investigators want to assess differences in lung function and bronchial inflammation of
      young smokers and non-smokers with (BMI > 30) and without obesity (BMI < 25)(4 patient
      groups). The aim of the study is to compare differences in lung function (VC, FEV1, VC/FEV1,
      metacholine challenge) and bronchial inflammation in relation with smoking history and levels
      of exhaled CO. For the latter the investigators will analyze the levels of IL-8, IL-6, TNF
      alpha and INF gamma and mRNA of LBP, TLR2 and TLR4 in sputum. Further, inflammatory markers
      e.g. low CRP and inflammatory cytokines levels in the blood will be investigated. The aim is
      to describe a early stage of chronic obstructive pulmonary disease caused by cigarette smoke
      in juvenile smokers, and the relationship between bronchial inflammation and obesity in
      adolescents.
    

Detailed description: 
      Tobacco smoke is the crucial factor at the beginning and in the course of the bronchial
      inflammation leading to COPD. It has been shown that cigarette smoke in vitro leads to a MAP
      kinase and NF-κB-dependent increase of pro-inflammatory cytokines, and inhibits
      bacteria-induced expression of β-defensins. Several studies revealed an increase of
      inflammatory cytokines like IL-8 and TNF in the sputum of smokers. Further studies
      demonstrated an up regulation of LTB4 and LBP possibly due to the LPS derived from tobacco
      smoke. Hasday et al could show that up to 15 ng per cigarette LPS is released. In principle,
      the cigarette smoke exposure liked a mild LPS inhalation. In separate work, we could show
      that LPS inhalation in healthy non-smokers to an increase of CRP and LBP concentrations in
      the serum lead. In another study of adolescents, 24 smokers (age 17.7 years) and 24
      non-smoking (age 17.5 years) were compared. The CO in smokers was significantly increased,
      and the NO concentrations decreased. At the same time there was a significantly greater
      bronchial hyperreagibility in the smoker group.

      According to a recent study in Germany (KiGGS study), already 31% of the adolescents' boys
      and 32% of the girls do smoke. The social status is of great importance. Boys and girls from
      families with a low social status smoke more frequently than those from families with
      middle-and especially with higher social status. Similarly obesity is linked to the social
      status with overweight occurring more often in families with a lower social status.

      A visceral obesity is closely associated with the risk of type-2-diabetes as well as other
      aspects of the metabolic syndrome. However, the existing insulin resistance is of fundamental
      importance. Due to increased visceral fat depots and subsequently increased release of
      proinflammatory proteins various complications do occur.
    

Observational model: Cohort
Time perspective: Cross-Sectional
Sampling method: Non-Probability Sample
Study population: 
        Youth
      
Biospecimen description: 
      serum: total IgE, RAST urin: cotinine, leukotrienes sputum: leukotrienes, white cells whole
      blood
    
Keywords: BMI; obesity; CO; tobacco smoking; adolescents