Introduction The prevalence of childhood obesity is increasing in the last few decades, representing a growing danger to their health. It is recognised that obesity has an effect on lung function, with a lower tidal volume in obese people. Obesity, as well as malnutrition, may cause decrease in the volume of the lungs and increased incidence of respiratory symptoms

Objective Show if obesity and poorer nutritional status in healthy school children affect on their lung function.

Methods We performed the spirometric tests of lung function with Jeger’s spirometer „Vyntus spiro‘, previously calibrated with 1 litre pump, at 165 healthy boys and 135 healthy girls aged from 7 to 18 years in 4 elementary and 4 high schools in Pancevo. Flow-volume curve was made: We observed the VC, FVC, FEV-1, PEF, MEF 75, 50 and 25. Body mass index (BMI) was used to determine the level of nutritional status. According to BMI children were classified into four groups: obese, overweight, normal weight, poorly nourished. Spirometric values between groups were compared by Student’s T-test. Relations of BMI and spirometric test results were compared with Pearson correlation coefficient. Statistical significance was defined as a p value<0.05.

Results The results showed that the lung functions are in the reference values for all groups. Analysis of the results with Student T-test [N1] showed that over-nourished boys have statistically significant (p<0.05) better values of VC, FVC, MEF 50, and MEF-25 compared to obese children, and better values of VC, FVC, FEV-1 and MEF-50, compared to the less nourished children. Pearson correlation coefficientshowed a slight negative correlation of BMI and VC values in obese male children (r: 0.28), and slight positive correlation in the poorly nourished male children (r: 0.33). In obese, overweight and normal weight girls pulmonary function values were equal, but decreased in VC and MEF-50 in poorly nourished, but not statistically significant.

Conclusion Obesity, as well as malnutrition have an influence on lung function in schoolchildren in Pancevo with a greater influence in male compared to female children.