Vital capacity, forced vital capacity, forced
expiratory volume in 1 second, and forced
expiratory volume in 1 second percent (as a
percentage of forced vital capacity) were measured
using a vitalograph spirometer. The recording was
done with each subject standing, without nose clips
procedures were carefully explained and
demonstrated to each subject and then the tests were
carried out. Each anthropometric or lung function
parameter was measured by a trained technician
familiar with the procedure. The use of one observer
per measurement was maintained throughout the
study. The leader of the team randomly repeated
some of the measurements to validate their accuracy.and with the lips firmly applied around the
disposable mouthpiece. The subject inspired
maximally and then expired as forcefully and rapidly
as possible into the vitalograph. Three attempts were
made and the best of the three spirogram was
selected (Afolabi et al, 1996; Al-Neaimi et al, 2001).
The value of VC, FVC, and FEV1 was read off the
selected spirogram