Lung function in children with asthma is associated with lean mass, not fat mass, according to [removed]researchers[/removed] at the Department of Respiratory and Sleep Medicine, Hunter Medical Research Institute, New South Wales, Australia, who found that the positive association between BMI z-score and respiratory function in male children is driven by lean mass.
A positive relationship between lung function and body mass index (BMI) in boys was driven primarily by increases in lean mass, while fat mass had no relationship with lung function in either gender, according to the authors.
“While monitoring body weight is a simple and practical way of tracking weight change in the clinical setting, our data demonstrate that body composition measurement can reveal important information about the relationship between body weight and lung function in children,” the authors wrote.
“An increased BMI indicates not only increased fat mass but also increased lean mass due to the effects of over-nutrition and weight bearing.”
The authors suggest that increased lean mass may represent increased strength of the diaphragm and chest wall to expand and contract, resulting in higher spirometry values.