Figure 1

Progression of lung function with age. A) Changes assessed by repeated measurements of plethysmographic functional residual capacity (FRC_pleth), functional residual capacity obtained by the multibreath nitrogen washout (FRC_MBNW), and volume of trapped gas (V_TG). V_TG was calculated as the difference between FRC_pleth and FRC_MBNW. B) Changes of lung clearance index (LCI) as a measure of ventilation inhomogeneities and effective specific airway resistance (sR_eff), as measure of airway narrowing. C) Changes of forced vital capacity (FVC), forced expired volume in one second (FEV1) and maximal expired flow at 50% FVC (FEF₅₀) in relation to age. All parameters expressed as z-scores.