Pubertal growth curves of ventilatory function: relationship with childhood respiratory symptoms

This study describes longitudinal growth patterns of ventilatory function in relation to the growth of standing height and weight of boys and girls aged 12.5 to 18 yr with or without a positive history of prepubertal respiratory symptoms. Ventilatory function was characterized by FVC, FEV1, peak expiratory flow (PEF) and maximal expiratory flow at 50% of the FVC (MEF50), derived from maximum expiratory flow volume (MEFV) curves. Data on respiratory symptoms and MEFV curves were obtained in a longitudinal survey of 404 children from a Dutch secondary school. Measurements were made at 6-month intervals between 1978 and 1985. The subjects selected for analysis comprised 151 boys and 118 girls for whom between nine and 14 measurements were available. In asymptomatic boys, the average peak growth rate of standing height occurred at about 14 yr, whereas the growth rates of the ventilatory function indices peaked about 0.8 (FVC) to 1.5 (MEF50) yr later. Weight growth paralleled that of FVC and FEV1. In girls, growth rates of all indices decreased over the whole age range. Adolescents with a positive history of prepubertal respiratory symptoms exhibited lung growth parallel to asymptomatic subjects, but at a lower level. In symptomatic boys, and to a lesser extent in girls, we found consistently lower levels of FVC, FEV1, and MEF50. We conclude that adolescents with a positive history of prepubertal respiratory symptoms, even if they lose their symptoms, remain at a disadvantage with respect to their ventilatory function when they reach adulthood.