Spirometry at adolescence.

Residual volume (RV), functional residual capacity (TGV) and total lung capacity (TLC) have been measured in 42 adolescents aged 16-22 years (22 young men and 20 young women) and in 60 children aged 12-15 years (29 boys and 31 girls) who were selected as having the same ranges of heights. TLC and TGV were related to height in each age and sex group; the slope of the regression curves did not differ between subgroups. RV was related to height in the boys and girls and not in the adolescents; however the number of subjects in each group was small. Relative to height the residual volumes of boys and girls were similar and in both sexes were larger than those for adolescents. Amongst the latter the values for young women were smaller than those for young men. The possible mechanisms are discussed.