Lung Function and Structure in Healthy Infants and Infants With Recurrent Wheezing
Condition: Asthma; Wheezing; Infant
MeSH terms: Respiratory Sounds
Study type: Observational

Summary: 
      Infants will be enrolled into this study in one of three groups. First, there will be a group
      of full term infants with no history of wheezing. Second, there will be a group of infants
      receiving a ct scan that is non-respiratory related. Third, there will be a group of infants
      that are born full term but have a history of wheezing of at least 3 episodes. The three
      groups will be compared to see if there is a difference in lung function, lung structure and
      lung size. Besides comparing the testing results we will be evaluating environmental and
      inherited characteristics. There are 2 purposes of this study. The first purpose is: To
      determine whether asymptomatic groups of infants at high risk for wheezing (Environmental
      tobacco smoke (ETS) exposure, Fm Asthma, male Gender) have fixed or reversible airway
      narrowing. The second purpose of this study is: To determine the relative contributions of
      fixed and reversible airway narrowing in infants with recurrent symptomatic wheezing, and to
      determine whether fixed and reversible airway narrowing is related to ETS exposure, Fm
      Asthma, and male Gender.
    

Detailed description: 
      Among asymptomatic healthy infants decreased airway function is found in infants exposed to
      environmental tobacco smoke (ETS) or with history of family asthma (Fm Asthma), or male
      gender. These infants are at significantly greater risk of wheezing during infancy. These
      findings indicate that genetic and environmental factors affect the mechanical determinants
      of airway function and that among healthy infants variations of these mechanical determinants
      contribute to the increased risk of developing airway obstruction severe enough to result in
      clinical symptoms of wheezing. The mechanisms of reduced airway function in these at risk
      infants are not known. In adults reduced airway function is a result of airway narrowing,
      increased airway compliance, or decreased pulmonary elastic recoil. The same is thought to be
      true in infants. The cause of airway narrowing may be functional (reversible by
      bronchodilators) or structural (fixed, not reversible by bronchodilators) or have components
      of both. Fixed determinants of airway narrowing include small absolute airway size, thickened
      airway wall, decreased elastic recoil, and small airway size relative to lung volume.
      Reversible determinants include airway hyper-responsiveness and inflammation. Understanding
      the alterations of airway function that increase the risk of airway disease will be decisive
      in the development of strategies for the prevention and treatment of wheezing in infants and
      children, and hence, a reduction of morbidity and mortality.

      It is not known whether infants with recurrent wheezing have persistent airway narrowing when
      not acutely symptomatic, and whether airway function in these infants is related to ETS
      exposure, Fm Asthma, and male gender. When recurrently wheezy infants are asymptomatic,
      airway function may be low or normal, and low airway function may be fixed or reversible with
      a bronchodilator. It is important to determine whether these infants have functional and
      structural abnormalities when they are not acutely symptomatic, and to determine how lung
      structure relates to lung function. Only then can we design effective therapeutic
      interventions for recurrently symptomatic infants, as well as, design early intervention
      strategies.

      The Specific aims of this project are:

      Specific Aim # 1: To determine whether asymptomatic groups of infants at high risk for
      wheezing (Environmental tobacco smoke (ETS) exposure, Fm Asthma, male Gender) have fixed or
      reversible airway narrowing.

      Specific Aim # 2: To determine the relative contributions of fixed and reversible airway
      narrowing in infants with recurrent symptomatic wheezing, and to determine whether fixed and
      reversible airway narrowing is related to ETS exposure, Fm Asthma, and male Gender.

      We propose to answer these important questions of lung function and structure in infants
      using state of the art methodologies
    

Observational model: Case-Control
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        We are recruiting infants with asthma and wheezing from pulmonary outpatient clinics at
        Riley Hospital for children. The full term healthy infants were recruited by advertisements
        in the local Indy's Child Magazine. These children were volunteers from Indianapolis and
        surrounding counties.
      
Biospecimen description: 
      We collect hair samples to analyzed for nicotine and cotinine.
    
Keywords: Asthma; Wheezing; Infant