Speaker's Highlight

• Don Sin University of British Columbia, St. Paul Hospital (Canada)
  Kenneth R. Chapman Toronto General Hospital Research Institute (Canada)
• Parameswaran Nair McMaster University (Canada)
  Carolyn Calfee UCSF (U.S.A.)
• Gregory P. Downey University of Colorado School of Medicine (U.S.A.)
  David A. Schwartz University of Colorado School of Medicine (U.S.A.)
• Neil Schluger Tuberculosis Control Branch, California Department of Public Health (U.S.A.)
  Nick Kim Critical Care & Sleep Medicine, University of California San Diego (U.S.A.)
• Nicola Hananiah Baylor College of Medicine (U.S.A.)
  Jae-Joon Yim Seoul National University College of Medicine (Republic of Korea)
• Koichiro Asano Tokai University School of Medicine (Japan)
  Diahn-Warng Perng Taipei Veterans General Hospital (Taiwan)
• Konstantinos Kostikas University of Ioannina (Greece)
  Karin Klooster University Medical Center Groningen (Kingdom of the Netherlands)

• Lung Function Trajectories from Childhood to Adulthood

  Lung health develops across the entire life course. Airway growth, immune maturation, exposures, and respiratory infections interact during childhood and adolescence, shaping the level of lung function reached in early adulthood and influencing the risk of chronic respiratory disease later in life.

  The idea of lung function trajectories from childhood to adulthood moves clinical attention beyond a single spirometry result. A low measurement may reflect delayed growth, persistent obstruction, or a temporary response to illness. Repeated assessment reveals which pattern is emerging and when intervention may have the greatest value.

  This perspective is highly relevant to respiratory physicians, pediatricians, primary care teams, and researchers attending a congress connected with APSR and KATRD. It links developmental biology with practical care, population health, and the prevention of chronic lung impairment.

  Why early lung development matters

  Lung capacity increases throughout childhood and adolescence as the airways and chest mature. Peak lung function is generally achieved in early adulthood, although the timing and level vary according to sex, genetics, body size, physical activity, socioeconomic conditions, and environmental exposure.

  A person who reaches a lower maximal level has less physiological reserve. Normal age-related decline may therefore bring symptoms and airflow limitation earlier, even when the annual rate of deterioration is not unusually fast. This helps explain why adult respiratory disease can begin with events and exposures that occurred decades earlier.

  Patterns revealed by repeated testing

  Longitudinal spirometry can identify several clinically meaningful patterns. Some children maintain expected growth and enter adulthood with preserved lung function. Others begin with low values but follow a parallel path, suggesting early developmental limitation rather than rapid decline.

  A third pattern involves accelerated loss after a period of normal or near-normal function. Recurrent wheeze, poorly controlled asthma, tobacco smoke, air pollution, occupational hazards, obesity, and severe respiratory infections may all contribute. A fourth trajectory combines low initial function with faster subsequent decline and deserves particular attention.

  Interpretation should include forced expiratory volume in one second, forced vital capacity, the FEV1/FVC ratio, bronchodilator response, symptoms, exacerbation history, and exposure history. Predicted values and reference equations must also be selected carefully, especially in diverse populations.

  From childhood risk to adult respiratory health

  Asthma is one of the clearest examples of a condition that can influence lung growth. Persistent childhood asthma, frequent exacerbations, airway remodeling, and poor adherence to controller therapy may reduce the likelihood of reaching expected adult lung function. However, not every child with wheeze follows the same course.

  Premature birth, bronchopulmonary dysplasia, cystic fibrosis, congenital airway disease, tuberculosis, and repeated lower respiratory infections can also alter pulmonary development. Early-life nutrition and maternal smoking are important influences, while secondhand smoke and household air pollution remain modifiable risks in many communities.

  Adolescence is a critical transition period. Smoking and vaping may begin, treatment routines can become inconsistent, and specialist follow-up may be interrupted. A structured handover from pediatric to adult services can preserve clinical information and identify changes before a preventable decline becomes established.

  Comparing common trajectory patterns

  A trajectory should never be assigned from one abnormal reading. Age, height, test quality, symptom burden, and the direction of change all matter. The following framework can support discussion during case review and clinical research.

  Trajectory pattern	Typical signal	Possible contributors	Clinical priority
  Expected growth and preservation	Measurements remain within the expected range	Healthy development, controlled exposures	Reinforce prevention and routine monitoring
  Persistently low but parallel	Low values with a stable growth pattern	Prematurity, early infection, developmental limitation	Confirm quality, investigate causes, support lung health
  Early decline	Normal or borderline function followed by faster loss	Poorly controlled asthma, smoking, pollution, recurrent infection	Identify reversible drivers and intensify follow-up
  Low start with accelerated decline	Reduced baseline function and worsening over time	Complex disease, severe exposure burden, chronic inflammation	Specialist assessment and coordinated long-term care
  Variable or fluctuating function	Large changes between visits	Asthma activity, infection, effort, inconsistent treatment	Repeat testing and correlate with symptoms and treatment

  Making measurements clinically useful

  Good longitudinal care begins with reliable testing. Spirometry should meet technical quality standards, and results should be interpreted using appropriate reference equations rather than fixed thresholds alone. Where available, z-scores and lower limits of normal can improve assessment across ages and body sizes.

  Clinicians should record the context of each test, including recent infection, medication use, exacerbations, physical activity, smoking exposure, and occupational or household irritants. A falling FEV1 may have a different meaning during acute illness than during a symptom-free period.

  Electronic health records can make trends easier to visualize, but numbers should remain connected to the patient’s lived experience. Exercise tolerance, school or work attendance, sleep quality, rescue medication use, and activity limitation may reveal meaningful deterioration before a dramatic spirometric change appears.

  Priorities for prevention and follow-up

  Trajectory-based care is most valuable when it leads to timely action. A respiratory team can use serial findings to tailor education, exposure reduction, pharmacological treatment, rehabilitation, and referral rather than waiting for irreversible impairment.

  Practical priorities include:

  • Establish high-quality baseline spirometry when clinically appropriate and repeat it at meaningful intervals.
  • Control childhood and adolescent asthma with an individualized action plan, correct inhaler technique, and regular review.
  • Reduce exposure to tobacco smoke, vaping aerosols, biomass fuel, traffic pollution, and occupational irritants.
  • Protect lung development through vaccination, physical activity, healthy nutrition, and prompt evaluation of recurrent infections.
  • Create a documented transition plan that carries spirometry trends, diagnoses, therapies, and risk factors into adult care.

  Building a life-course respiratory agenda

  Research into developmental lung trajectories can strengthen prevention strategies across Asia and beyond. Multicenter cohorts, harmonized spirometry methods, culturally appropriate reference standards, and long-term follow-up are needed to distinguish biological variation from avoidable disadvantage.

  The APSR and KATRD community offers an important setting for connecting pediatric and adult respiratory medicine. Discussions that bring together clinicians, epidemiologists, physiologists, and public health specialists can clarify how early interventions affect later outcomes and which populations require more intensive surveillance.

  For conference participants, the central message is practical: lung function is a moving pathway, not a fixed label. Reviewing that pathway across childhood, adolescence, and adulthood can reveal hidden risk, improve communication between specialties, and support earlier action.

  Bring longitudinal spirometry, developmental respiratory research, and clinical experience into the congress conversation. Share evidence that can help transform isolated measurements into prevention plans and ensure that every stage of life contributes to healthier lungs.

  Richard Russell Nuffield Department of Clinical Medicine, University of Oxford (United Kingdom)
• Mona Bafadhel King’s College London (United Kingdom)
  David Jackson Guy’s and St Thomas’ Hospital, King’s College London (United Kingdom)
• James Chalmers University of Dundee (United Kingdom)
  David Price University of Aberdeen (United Kingdom)