Study of dynamic lung function parameters in normal, overweight, and thin school boys

Background: In India, childhood undernutrition and obesity both are major health concerns. Lung functions are affected in both thin and obese children. Body mass index (BMI)-for-age is a simple tool suggested by the World Health Organization for categorizing children and adolescents below 19 years. Aim: The aim of the study was to compare dynamic lung function parameters of overweight and thin boys with normal boys. Materials and Methods: One hundred and fifty school boys of age group 12–16 years were included as a convenience sample after screening 234 students. BMI-for-age chart developed by the World Health Organization was used to categorize participants into normal (n = 50), overweight (n = 50), and thinness (n = 50) group. Forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), FEV3, peak expiratory flow rate (PEFR), and forced expiratory flow (FEF) at the midportion of FVC (FEF25-75) were measured by MEDSPIROR. Unpaired t-test and Pearson correlation (r) were used according to the necessity. Results: Thin boys had lower FVC (P = 0.019), FEV1 (P = 0.048), FEV3 (P = 0.007), PEFR (P = 0.0002), and FEF25-75 (P = 0.003) compared to normal boys. Overweight boys showed significantly increased FVC (P = 0.019), FEV1 (P < 0.0001), and FEV3 (P = 0.0005) compared to normal boys. BMI of thin boys showed positive correlation with FVC (r = 0.49, P = 0.0003), FEV1(r = 0.40, P = 0.003), and FEV3 (r = 0.53, P < 0.0001). Correlation coefficients were not significant for BMI and dynamic lung function test parameters in normal and overweight boys. Conclusions: Thin boys have lower dynamic lung functions than normal boys. Increase in body weight may help in increasing their lung function status