Age-related changes of pulmonary diffusion capacity components in healthy adolescents

Abstract

Introduction: Lung diffusion capacity for CO (DLCO) increase with children’s growth proportionally to height, weight and age but decreases when corrected for the alveolar volume (DLCO/VA). The aim of the present study was to dissociate the growth-related changes in the membrane and the capillary component of the pulmonary diffusion and if those parameters influence aerobic exercise capacity (V02max). Methods: Eighty-nine healthy adolescents or young adults separated in 4 age groups (12-13, 14-15, 16-17 and 18-22 years old) performed a cardio pulmonary exercise test (CPET) and a measurement of lung diffusion capacity (DL) for carbon monoxide (CO) and nitric oxide (NO) with the single breath method at rest. DLCO, DLNO, alveolar ventilation (VA), diffusivity of the alveolocapillary membrane (Dm), capillary blood volume (Vc) and the VO2max were recorded. Results: Results are displayed in table 1. VA improved progressively with growth. DLNO, DLCO, Dm and Vc increased in parallel from 12-13 years to 15-16 years but not later. This induced a decrease in DLCO/VA and DLNO/VA in young adults. VO2max was positively correlated with DLCO and DLNO in 16-17 years old adolescents (p Conclusion: DLCO, DLNO and the membrane and the vascular component of the pulmonary diffusion increase parallelly during adolescence with no relation to VO2max. Young adult have a slight lower diffusion capacity when corrected for alveolar volume and is correlated to aerobic exercise capacity.