RESUMO
Background: Pulmonary function test (PFT) is used to diagnose the underlying cause of respiratory symptoms in children and adolescents. It is also used to monitor the status of those with chronic lung diseases. In clinical practice, spirometry is the investigation of choice for the overall assessment of pulmonary function and is equated with the PFT in day to day practice the assessment of lung function. Aim and Objective: The aim of the study was to determine pulmonary function (as measured by FEV1 and FEV6) among school going children of age group 9� years and its variability with age, sex, height, and regional difference. Materials and Methods: This cross-sectional study was conducted among 703 normal healthy school children (335 boys and 368 girls) of Thiruvananthapuram city aged 9� years during 2015�16. The study group included both South Indian and North Indian children. Height, weight, and BMI were measured. All included children were tested in a sitting position with the head straight after taking written consent from parents. Spirometry was done using the instrument 揤italograph- COPD 6.� It displays FEV1 and FEV6. The FEV6 is used as a surrogate marker of FVC. Results: FEV1 and FEV6 were found to be statistically significant in the study group. Both FEV1 and FEV6 were higher in boys than girls. In both boys and girls, FEV1 and FEV6 values showed strong positive correlation with age, and height which was found to be statistically significant (P < 0.001). North Indian children have got higher FEV1 and FEV6 values than South Indian children. This was also found to be statistically significant (P < 0.001). Conclusion: Variables such as FEV1 and FEV6 values showed strong positive correlation with age and height in both sexes. By regression analysis, it was found that age, gender, and height were the significant predictors for both FEV1 and FEV6.