Lung function tests in normal Indian children.

The forced vital capacity, forced expiratory volume in one second, peak expiratory flow, mid-expiratory flow and maximum voluntary ventilation was measured in 632 healthy, normal children from Metropolitan city of Bombay using computerized spirometer. The children were between age range 6 years to 15 years and belong to high or middle and lower socio economic status. The pulmonary function data was separated by sex, and classified on the basis of height and age. The mean and standard deviation for was calculated for every such variable. The lung function variables show a linear positive correlation with height and age. Forced vital capacity and one second forced expiratory volume show a spurt after height 150 cm. Boys show higher values for lung function variables than girls except for mid expiratory flow rates where girls have higher values than boys over height 140 cm and age 9 yrs. Stepwise regression equation was calculated using height, age and weight as independent variables. Height explained the maximum variance in lung function parameters. Use of logarithmic equations for age, weight do not improve the degree of correlation. Hence, for clinical evaluation of child's lung function, height is the most significant independent parameter in comparison to age and weight.