This article delves into a groundbreaking study published in The Lancet Respiratory Medicine, which for the first time comprehensively reveals the evolution of lung capacity from childhood to old age. Utilizing an innovative “accelerated cohort design,” researchers analyzed data from over 30,000 individuals aged 4 to 82 across multiple studies. Contrary to traditional beliefs, the study shows that lung function begins to decline immediately after reaching its peak at around 20 - 23 years old, rather than maintaining a stable period. Additionally, it uncovers new insights into the impact of persistent asthma and smoking on lung function. This research not only challenges conventional models but also emphasizes the significance of early respiratory health promotion and monitoring, providing crucial guidance for future research, clinical practice, and public health policies.
How robust is your lung capacity? Astonishingly, the loss of human lung capacity commences as early as between the ages of 20 and 25!
Respiration stands as an elemental necessity for life, and lung capacity serves as a pivotal metric for gauging respiratory health. In contemporary society, with the intensification of environmental pollution, alterations in lifestyle patterns, and the increasing aging of the population, the incidence rate of respiratory system diseases has been on the rise. Consequently, comprehending the trajectory of lung capacity changes from childhood to old age is of paramount importance for the early prevention and treatment of respiratory diseases.
A Pioneering Approach to Uncover Lung Function Trajectories
Recently, a research report titled “General Population-Based Lung Function Trajectories Over The Life Course: An Accelerated Cohort Study” was published in the international journal The Lancet Respiratory Medicine. Scientists from institutions such as the Barcelona Institute for Global Health, through this study, for the first time, illuminated the evolution process of lung capacity throughout the lifespan, thereby offering a novel fundamental framework for assessing lung health.
The conventional viewpoint posits that lung function reaches its peak around the age of 20 - 25, followed by a stable phase, with decline only occurring in middle and old age due to pulmonary aging. However, this model was primarily grounded in studies that failed to cover the entire life course. To bridge this knowledge gap, the researchers employed the “accelerated cohort design” method, integrating data from multiple cohort studies to encompass the entire age spectrum from 4 to 82 years old.
The researchers incorporated more than 30,000 individuals aged 4 to 82 from eight population-based cohort studies in Europe and Australia. These studies include the Avon Longitudinal Study of Parents and Children (ALSPAC) in the UK, the BAMSE study in Sweden, the European Community Respiratory Health Survey (ECRHS), the INMA study in Spain, the PIAMA study in the Netherlands, the SAPALDIA study in Switzerland, the Tasmanian Longitudinal Health Study (TAHS) in Australia, and the Vlagtwedde-Vlaardingen study in the Netherlands.
Figure: Summary of participant visits, ages, and follow-up times* according to source cohort study, and contribution of each cohort study to the accelerated cohort (absolute observation numbers) by 5-year age groups
New Insights into Lung Function Development and Influencing Factors
The study uncovered that the development of lung function can be divided into two distinct phases: the first is the rapid growth period during childhood, and the second is a slow growth phase until it reaches its peak. Specifically, the FEV1 (the volume of air exhaled in one second) of females peaks at approximately 20 years old, while that of males peaks around 23 years old. Surprisingly, the study did not detect the existence of a stable period after the peak.
Researcher Judith Garcia-Aymerich explained, “Previous models suggested that lung function would remain stable until the age of 40. However, our data clearly demonstrate that lung function starts to decline immediately after reaching its peak, much earlier than previously thought.”
Furthermore, the study also discovered that the impacts of persistent asthma and smoking on lung function differ from previous understandings. Individuals with persistent asthma reach their FEV1 peak earlier and maintain lower levels throughout their lives. On the other hand, smoking is associated with an accelerated decline in lung function starting from the age of 35.
Figure: Sex-specific FEV1,* trajectories during the life course
This research offers the first comprehensive panorama of the evolution of lung capacity from childhood to old age and reveals the fact that lung function begins to decline right after reaching its peak. This finding challenges the traditional lung function model and underscores the importance of promoting respiratory health in the early stages of life and utilizing spirometry for early monitoring.
The researchers emphasized the significance of using spirometry to detect low lung function in the early stages of life. This can contribute to the prevention of chronic respiratory diseases in adulthood. Early detection of low lung function may enable timely interventions, thereby preventing the onset of chronic respiratory diseases in adulthood.
Conclusion
In conclusion, this study has not only deepened our understanding of the natural evolution of lung capacity but has also paved the way for future respiratory health research and clinical practice. The findings of this study hold great significance for the formulation of public health policies, clinical prevention and treatment decisions, as well as drug evaluation in the pharmaceutical industry. By enhancing our comprehension of lung function changes, we can more effectively promote the respiratory health of the population and elevate the overall quality of life.