How childhood body composition determines lung health in adults

A new study now finds that lung health in adolescents is determined by the amount of fat mass they had as children.

This Barcelona Institute for Global Health (ISGlobal) research has been published in the American Journal of Respiratory and Critical Care Medicine.

The study reports that boys and girls with more muscle mass in childhood and adolescence have higher lung function. The researchers also found that boys, but not girls, with more fat mass have lower lung function.

Previous studies had looked at the association between overall body mass and lung function, but they found contradictory results.

"Some studies related higher body mass with higher lung function while others found higher body mass related to lower lung function," said Judith Garcia-Aymerich, senior study author. "We hypothesised that previous contradictory results could be attributed to the fact that overall body mass does not account for the different contribution of fat and muscle mass," she added.

Specifically, the study found:

-In boys and girls, higher muscle mass was associated with higher levels and lung growth rates of Forced Vital Capacity (FVC), the total amount of air a person can exhale taking the deepest breath possible; Forced Expiratory Volume in one second (FEV1), the amount of air a person can forcefully exhale in one second; and Forced Expiratory Flow at 25-75 per cent (FEF25-75), a measure of the speed that air comes out of the lungs.

-In boys and girls, higher fat mass was associated with lower levels of FEV1/FVC, a measure of airflow limitation often used to help diagnose asthma and chronic obstructive pulmonary disease (COPD).

-In boys, but not girls, higher fat mass was associated with lower levels and lung growth rates of FEV1 and FEF25-75.

"Our results highlight that body composition, and not just overall body mass, should be assessed when studying the health effects of weight in children", said Gabriela P. Peralta, first author of the study.

"We believe that body composition in childhood and adolescence may play a role in future respiratory health," she concluded.