Lung function in white children aged 4 to 19 years: II--Single breath analysis and plethysmography.

OBJECTIVE A study was performed to determine reference ranges for whole body plethysmographic gas volumes and single breath gas transfer in healthy prepubertal and pubertal schoolchildren. METHODS The study was performed in 772 white London schoolchildren (455 male) who were clinically examined, assessed auxologically and, in 63% of cases, pubertally staged. Regression equations for the calculation of standard deviation scores were derived. RESULTS Male lung function variables showed a discontinuous pattern of increase with standing height. Linear increases until puberty were followed by a sudden pubertal rise and a further increase with height which was more marked than before puberty. Correction for varying thoracic dimensions eliminated these changes. In females a smoother curvilinear relationship was observed with no correction possible for thoracic size. CONCLUSIONS Male puberty leads to profound changes in pulmonary function mostly related to thoracic size, an effect not observed in females.