Peripubertal lung growth pattern in Japanese school children.

The peripubertal growth pattern of lung function remains underexplored in relation to height growth. This study aimed to first clarify the relationship between the age at peak growth velocity in lung function variables and the age at peak height velocity (APHV) and second identify sex differences in lung function growth patterns. Lung function and height were measured annually in children aged 9-15 years (elementary schools, N = 1307; junior high schools, N = 792) from 2011 to 2018. Children were categorized quarterly according to APHV, using the Super Imposition by Translation and Rotation model. The age at peak growth velocity for forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV) lagged behind APHV by 2-12 months. The later the APHV, the greater the numerical lag, although this was not significant. In males, but not females, the trajectory of FEV/FVC values gradually decreased to reach the lowest levels and then gradually increased with age (U-shaped curve) in all quartiles. Both FVC and FEV overwhelmed in males compared with those in females when the height exceeded 150-160 cm. Our results highlight significant variability in peripubertal lung growth with height and sex-related differences in the growth of airways and parenchymal components.