Study: NCT01269528

Intervention type: OTHER
Intervention: Methacholine Challenge Test (MCT)
Description: MCT challenge with determination of methacholine concentration that causes a 20% decrease from baseline FEV1 (forced expiratory volume in the 1st second of expiration) - PC20-FEV1 - is a well-documented method of assessing bronchial hyper-reactivity (BHR) in both adults and children. Our group has shown that the determination of PC20 by spirometry is feasible in preschool children. MCT is considered safe in this age group and our group has extensive experience with no adverse events. In the current study MCT will be performed (for the first time) in premature babies born at 30-32 weeks of gestation during 2008-2009 when they reach the age of 3-4 years (2011 and 2012, respectively). The results of MCT of the two groups will be compared.

Intervention type: OTHER
Intervention: Methacholine Challenge Test (MCT)
Description: MCT challenge with determination of methacholine concentration that causes a 20% decrease from baseline FEV1 (forced expiratory volume in the 1st second of expiration) - PC20-FEV1 - is a well-documented method of assessing bronchial hyper-reactivity (BHR) in both adults and children. Our group has shown that the determination of PC20 by spirometry is feasible in preschool children. MCT is considered safe in this age group and our group has extensive experience with no adverse events. In the current study MCT will be performed (for the first time) in premature babies born at 30-32 weeks of gestation during 2008-2009 when they reach the age of 3-4 years (2011 and 2012, respectively). The results of MCT of the two groups will be compared.

Intervention type: OTHER
Intervention: Monthly telephone contact
Description: Monthly telephone contact with the parents/caregivers will be scheduled from enrollment until the final visit at age 3-4 years. Subject illnesses and other medical events occurring during the past month will be recorded at each monthly follow-up.

Intervention type: OTHER
Intervention: Monthly telephone contact
Description: Monthly telephone contact with the parents/caregivers will be scheduled from enrollment until the final visit at age 3-4 years. Subject illnesses and other medical events occurring during the past month will be recorded at each monthly follow-up.

Intervention type: OTHER
Intervention: Visits to the study site
Description: Visits to the study site will be conducted at 6-month intervals in which physicians will record intercurrent doctor visits, emergency visits, and hospitalizations for respiratory symptoms.

Intervention type: OTHER
Intervention: Visits to the study site
Description: Visits to the study site will be conducted at 6-month intervals in which physicians will record intercurrent doctor visits, emergency visits, and hospitalizations for respiratory symptoms.

Intervention type: OTHER
Intervention: Blood Test
Description: For assessing IgE levels, Eosinophils count and cytokines levels

Intervention type: OTHER
Intervention: Blood Test
Description: For assessing IgE levels, Eosinophils count and cytokines levels

Intervention type: OTHER
Intervention: Fractional exhaled nitric oxide
Description: Participant blow tidal volume for determination of exhaled NO in Exhaled breath.

Intervention type: OTHER
Intervention: Fractional exhaled nitric oxide
Description: Participant blow tidal volume for determination of exhaled NO in Exhaled breath.