Lung volume and expiratory flow rates from pre- to post-puberty

Purpose: The purpose was to determine if the airways and lungs grow disproportionately from pre- to post-puberty in boys and girls. We hypothesized that the airways grow at a slower rate than lung volume (i.e. dysanapsis growth) during puberty and boys would exhibit more dysanaptic growth compared to girls. Methods: Twenty-one pre-pubescent children [11 boys (pre 10.1 ± 0.5 years, post 15.3 ± 0.5 years); 10 girls (pre 9.4 ± 1.0 years, post 14.1 ± 1.0 years)] performed pulmonary function tests (PFTs) ~5 years ago from an original cohort of 40 children. These 21 children performed PFTs, which included forced vital capacity (FVC) and forced expiratory flow at 50 % FVC (FEF₅₀). Static pressure at 50 % of FVC [Pst(L)_50 %] was estimated based on age. Dysanapsis ratio (DR) was calculated [FEF₅₀ × FVC⁻¹ × Pst(L)_50 % ⁻¹]. Maturation status was determined via Tanner stages. Results: Stage of maturation was not different (p > 0.05) between boys and girls (4.2 ± 0.6 stage vs. 3.7 ± 0.7 stage, respectively). FVC and FEF₅₀ increased (p < 0.05), DR significantly decreased, and FEF₅₀/FVC was similar (p > 0.05) from pre- to post-puberty. FEF₅₀ and FVC significantly increased and DR decreased (p < 0.05) post-puberty for both sexes. Post-puberty, boys had a significantly larger FVC, but FEF₅₀, DR, and FEF₅₀/FVC were not different (p > 0.05) compared to girls. Conclusions: These data suggest that dysanaptic growth occurs during puberty and that it is not different between boys and girls.