Determinants of Early Cystic Fibrosis Lung Disease

Study Overview
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Brief Summary
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The overall objective of this study is to determine the impact early nutritional and respiratory indices have on early CF lung disease. This knowledge will guide clinical management of infants with CF, who are now primarily diagnosed through newborn screening.

Detailed Description
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The overall objective of this study is to determine the impact early nutritional and respiratory indices have on early CF lung disease. This knowledge will guide clinical management of infants with CF, who are now primarily diagnosed through newborn screening. We hypothesize that respiratory and nutritional indices during the first year of life are critical determinants of lung function in infants and preschoolers with CF. Aim #1 - To examine the relationship between nutritional status (weight-for-age (WFA) and weight-for-length (WFL)) at 6 months of age and lung function at 1-2 years of age in infants with CF. Hypothesis: Infants with CF with poor nutritional status at 6 months of age will have worse lung function, as assessed through the raised volume rapid thoracoabdominal compression technique and plethysmography, compared to those with better nutritional indices, defined as improved weight-for-age and weight-for-length. Aim #2 - To examine the relationship between nutritional status (WFA and WFL) in infants with CF at 12 months of age and the lung clearance index (LCI) at 3-5 years of age. Hypothesis: Infants with CF with poor nutritional indices at 12 months of age will have a higher (worse) LCI at 3-5 years of age compared to those with better nutritional status. Aim #3 - To delineate the relationship between passive tidal breathing lung function testing in infants with CF at 4-8 weeks of age and subsequent lung function at 6-12 months of age. Hypothesis: Abnormalities in passive tidal breathing lung function testing will be associated with abnormal infant pulmonary function testing obtained via the raised volume rapid thoracoabdominal compression technique and plethysmography at 6-12 months of age.

Official Title
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Determinants of Early Cystic Fibrosis Lung Disease

Conditions
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Cystic Fibrosis in Children

Intervention / Treatment
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* Diagnostic Test: Infant PFT
* Diagnostic Test: Lung Clearance Index
* Diagnostic Test: Passive tidal breathing


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Informed consent by a parent or legal guardian A confirmed diagnosis of CF by newborn screening and either a documented sweat chloride of at least 60 mEq/L by quantitative pilocarpine iontophoresis or a genotype with two CF-causing mutations One month to five years of age. Exclusion Criteria: Chronic lung disease not due to CF Contraindications to sedation, including structural abnormalities of the upper airway or chest wall and severe gastroesophageal reflux Gestational age < 36 weeks

Ages Eligible for Study
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Minimum Age: 1 Month
Maximum Age: 5 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Nutrition and Infant PFT<br>To examine the relationship between nutritional status (weight-for-age (WFA) and weight-for-length (WFL)) at 6 months of age and lung function at 1-2 years of age in infants with CF. | Diagnostic Test: Infant PFT<br>* Assessed through the raised volume rapid thoracoabdominal compression technique and plethysmography<br>|
| Nutrition and Lung Clearance Index<br>To examine the relationship between nutritional status (WFA and WFL) in infants with CF at 12 months of age and the lung clearance index (LCI) at 3-5 years of age. | Diagnostic Test: Lung Clearance Index<br>* The Lung Clearance Index is derived from the Multiple Breath Washout test. It is the cumulative exhaled volume (the volume of gas needed to wash out resident gas mixture out of the lungs) divided by the FRC. The FRC is the amount of air left in the lungs after normal exhalation.<br>|
| Passive Tidal Breathing and Infant PFT<br>To delineate the relationship between passive tidal breathing lung function testing in infants with CF at 4-8 weeks of age and subsequent lung function at 6-12 months of age. | Diagnostic Test: Infant PFT<br>* Assessed through the raised volume rapid thoracoabdominal compression technique and plethysmography<br>Diagnostic Test: Passive tidal breathing<br>* During quiet sleep, tidal breathing flow-volume curves are obtained. The tPEF/tE is calculated by taking the time it takes to reach peak expiratory flow divided by the total peak expiratory time.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Lung function | Forced expiratory volume in 0.5 seconds | 24 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Lung function - FRC | Functional Residual Capacity | 24 months | 
| Lung function - MBW | Multiple breath washout result | 24 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Nutritional Status, Infant Pulmonary Function Testing, Lung Clearance Index, Multiple Breath Washout