ABSTRACT
Objective: This study was to compare the pulmonary function, respiratory muscle strength, and physical activity level between obese and non-obese children and to determine the correlation between pulmonary function, respiratory muscle strength and physical activity level in both child groups. Methods: Thai healthy children aged between 10-12 years participated in this study. They were classified into an obese group with body weight > +3 standard deviations and a non-obese group with body weight between+ 1.5 standard deviations of children who have the same height. Children in both groups were measured for pulmonary function, forced vital capacity (FVC), and forced expiratory volume in one second (FEV1), FEV1/FVC ratio, vital capacity (VC), inspiratory muscle strength (MIP), expiratory muscle strength (MEP), and physical activity level. Results: The results showed that FVC, FEV1 and VC of the obese group were statistically higher than the non-obese group (p<0.05). FEV1/FVC ratio of the obese group was statistically lower than the non-obese group (p<0.05). MIP and MEP were not significantly different between the groups (p>0.05). Physical activity levels were not significantly different between the groups (p>0.05). Moreover, the results demonstrated that physical activity level in the obese group had no correlation with FVC, FEV1, FEV1/FVC ratio and VC (r = 0.203, 0.170, -0.067 and 0.133 respectively; p > 0.05) and similarly the non-obese group showed no correlation with FVC, FEV1, FEV1/FVC ratio and VC (r = 0.225, 0.168, -0.207 and 0.168 respectively; p > 0.05). Additionally, the results demonstrated that physical activity level in the obese group had no correlation with MIP and MEP (r = 0.151 and 0.355 respectively; p > 0.05) and similarly the non-obese group showed no correlation with MIP and MEP (r = 0.202 and 0.006 respectively; p > 0.05). Conclusion: This study provides information about the pulmonary function and respiratory muscle strength in Thai obese children. FVC, FEV1 and VC of the obese group were higher than the non-obese group. In addition, FEV1/FVC ratio of the obese group was lower than the non-obese group. Although, all parameters including pulmonary function of both groups were in the normal range. However, obese children tend to observe airway obstruction higher than non-obese children. Moreover, respiratory muscle strength and physical activity level were not different between groups. Additionally, physical activity level had no correlation with pulmonary function and respiratory muscle strength in both groups.