Higher body mass index and increased physical activity can assist in overcoming lung function deficits in early childhood, researchers find.

RT’s Three Key Takeaways:

  1. Higher levels of physical activity and a higher body mass index at age 4 are associated with accelerated lung function growth. This suggests that being active and having a higher BMI can help overcome early lung function deficits in children.
  2. The study identified four distinct growth trajectories for lung function among children aged 4-18: a low trajectory, a normal trajectory, a high trajectory, and a “catch-up” trajectory. The “catch-up” group, which started with lower-than-average lung function, showed accelerated growth and achieved normal lung function values by adolescence.
  3. The research highlighted several predictors of lung function growth including demographic and birth characteristics, allergic diseases, environmental exposures, and particularly physical activity and body mass. The study showed that children with fewer allergic diseases and higher activity levels were more likely to have better lung function growth patterns.

Increased levels of physical activity and a higher body mass index (BMI) play a key role in the recovery of early lung function deficits in children, according to a new study led by the Barcelona Institute for Global Health (ISGlobal).

These findings, published in Thorax, have implications for clinical practice, research, and public health policy, providing new insights into how to improve respiratory health from childhood to adulthood, according to the researchers.

Study Maps Variable Lung Growth Patterns in Children

The study analyzed data from the Spanish birth cohort of the INMA – Environment and Childhood project, which included 1,151 children and adolescents aged 4-18 years. The researchers measured lung function with spirometry. More specifically, the researchers measured forced expiratory volume in one second (FEV1), which is the volume of air exhaled in the first second during forced exhalation after a deep inhalation, and forced vital capacity (FVC). While FEV1 is an indicator of how open the airways are, FVC gives insights into the size of the lungs.

From the repeated spirometry, four trajectories of lung function growth were identified: a low trajectory (19% of the sample for both FEV1 and FVC), a normal trajectory (62% and 63%), a high trajectory (16% and 13%) and a final trajectory called “catch-up” (2% and 5% of the sample). The “catch-up” group started with lung function values below the low trajectory and showed accelerated growth between 4 and 10 years of age, reaching normal lung function values.

“The key finding of our study is that low lung function in early childhood does not automatically translate into poor lung function in early adulthood but that accelerated growth can recover early-life lung function deficits and result in normal values in adolescence,” says Sarah Koch, ISGlobal researcher and first author of the study, in a release.

High levels of Physical Activity and Body Mass Increase Lung Function

Using clinical records, questionnaires, and results from face-to-face visits with participants and their families, the team gathered information on possible predictors of lung function growth. 

These were grouped into four categories: demographic and birth characteristics, allergic diseases, smoking and other environmental exposures, and physical activity and body mass.

The study results show that accelerated lung function growth is mainly associated with higher levels of physical activity in early childhood (between the ages of 4 and 7) and higher body mass index at the age of 4.

“Our study confirms and goes beyond previous research on known predictors of lung function. Children with fewer allergic disease were more likely to have normal or high FEV1 trajectories. This supports previous evidence on how children’s allergic conditions affect lung function growth,” says Judith Garcia-Aymerich, PhD, ISGlobal researcher and senior author of the study, in a release.

Clinical and Public Health Implications

Early onset or accelerated lung function decline beyond what is expected as part of the normal aging process, is a clear risk factor for chronic respiratory disease. Therefore, understanding the determinants that predict lung function growth during childhood and adolescence is equally as important for the prevention of these diseases as understanding the determinants of lung function decline in later adulthood.

The results of this study have implications for clinical practice and public health policy. “Both clinical management and public health policies should support and promote a healthy diet and high levels of physical activity in children with low baseline lung function, suboptimal environmental conditions, or early-life allergies. This can help overcome growth limitations in lung function and improve respiratory health in childhood and adulthood,” says Koch in a release.

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