As part of our ongoing seminar series, the Centre of Excellence in Severe Asthma hosted Prof. Urs Frey, for a webinar on “Early-life Factors and Asthma and Lung Functional Development” on 25 October, 2017.
Presentation Summary:
Early-life lung development has long-term effects on the development of airways disease. Wheeze and reduced lung function in childhood increases the risk of developing lung disease later in life (including asthma and COPD). An understanding of how this occurs is important to identify preventative approaches to reduce disease burden.
No single mechanism leads to reduced lung functional growth. Rather, many small effects in early life contribute to long-term outcomes. Factors that affect early life lung development include tobacco smoke exposure, pollution, birth weight, breastfeeding and early-life airway remodelling. Some factors improve lung function growth, although with small effect sizes. Reduced air pollution, improved nutrition and appropriate asthma control are likely to improve long-term lung function.
Approaches that reduce the development of lung disease will likely require many changes. Each individual change will contribute to small improvements in lung function. When combined, these approaches may reduce the development of airway disease in later life.
Key Points:
- Development of airway disease (asthma and COPD) is influenced by lung development in early life
- Longitudinal studies demonstrate children with asthma or viral wheeze are at increased risk of developing COPD later in life
- Long-term tracking of lung function (FEV1) identifies reduced function in children with persistent airways symptoms
- Lower lung function in infancy (2-3 months of age) persists through to adulthood
- Respiratory impairment and symptoms may not become apparent until older age
- Lung development in early life is influenced by complex interactions between genetic background, damage and repair processes and environmental exposures
- Inherent risk factors include family history of airway disease, atopy and reduced lung function
- Pre- and peri-natal factors include exposure to tobacco smoke, air pollution, premature birth, intrauterine growth restriction (IUGR) and Caesarean section birth
- Early life and preschool factors include exposure to tobacco smoke, air pollution, nutrition, obesity and catch up growth
- Modifying factors in early-life may provide an opportunity to prevent the development of airway disease in later life
- Mechanisms contributing to disease development affect lung structure and growth, alter inflammatory responses, epithelial function and immune system development
- Effects are modified by the genetic background and influenced by environmental exposures
- Premature birth is a risk factor for reduced lung growth due to interrupted lung development
- Exposure to maternal tobacco smoke in pregnancy and/or the first 3-months of life is associated with an increased risk of developing respiratory symptoms
- Virus exposure in infancy and older maternal age are also associated with decreased lung function in adulthood
- Air pollution exposure in pregnancy is associated with lower lung function at 1-month of age
- Improved air quality results in improved lung functional growth
- Low birth weight and rapid early weight gain increases the risk of developing childhood asthma
- Breastfeeding improves school age lung function, but only in children born to mothers with asthma
- Inflammation leads to airway remodelling which may take time to develop
- Most prevention approaches to date have had relatively minor or variable effects on asthma development and lung function
- Early treatment with anti-inflammatory therapies does not appear to have sustained effects on lung function
About Prof. Urs Frey:
Prof. Urs Frey is Chair of Pediatrics and Medical Director at the University Children’s Hospital in Basel, Switzerland. He has a MD degree in Pediatrics from the University of Berne, Switzerland, and a PhD in Medical Physics from the University of Leicester, UK.
He is an established researcher in paediatric pulmonology, particularly in the field of asthma and developmental physiology. He leads a birth cohort study investigating genetic and environmental influences on infant lung development and is also interested in the mathematical modelling of complex airways disease. At the time of this presentation, he was on sabbatical leave at the Woolcock Institute in Sydney.
