LUNG-FUNCTION IN ESTONIAN CHILDREN - EFFECT OF SITTING HEIGHT

The present analysis formed part of the population study of Estonian s choolchildren and was undertaken in order to examine the relationships between lung function variables, standing and sitting height. We meas ured forced vital capacity (FVC), forced expiratory volume in 1s (FEV( 1)), peak expiratory flow and forced expiratory flows when 50 and 75% of FVC had been exhaled, and anthropometric indices in 645 healthy sch oolchildren, aged 6-18 years. The growth spurt in standing and sitting height occurred between the ages of 11 and 13 years in girls, and 13 and 15 years in boys. Growth spurts of lung parameters occurred during the same periods. FVC and FEV(1) showed close correlations (r = 0.89- 0.94) with all anthropometric parameters and age, whereas correlation coefficients for the flows were less close (r = 0.65-0.88). In boys, c orrelations between sitting height and lung function variables were gr eater than those with standing height. Using stepwise regression analy sis, in boys sitting height was selected in all lung function paramete rs, and in girls sitting height was never selected. We conclude that t here is a very close correlation between sitting height and lung funct ion variables. The use of sitting height in parallel with standing hei ght in predicted values for Estonian schoolchildren would make the val ues more exact.