Comparison of Respiratory Muscle Thickness, Lung Function, and Thoracic Cage Mobility in a 20s Male Adults according to Smoking Status

The aim of this study was to compare the respiratory muscle thickness, lung function and thoracic cage mobility in a 20s male adults according to smoking status. Forty-seven healthy males aged 20-29 participated in this study. The Fagerstrom Test for Nicotine Dependence (FTND) and Cigarette dependence scale-12 (CDS-12) were used to evaluate smoking status, and they were divided into smoking group (n=23), and non-smoking group (n=24). The thickness of respiratory muscles (diaphragm, intercostal muscle, external oblique, internal oblique, and transverse abdominis) were evaluated using the ultrasound at maximum exhalation and inhalations. And, to measure the pulmonary function, FEV1 and PEF were evaluated using digital peak flow instrument. Additionally, thoracic cage mobility was measured. As the results, there was no significant between smoking group and non-smoking group in respiratory muscle thickness at maximum inhalation. At maximum exhalation, only external oblique thickness was a significantly lower in smoking group than non-smoking group (p=.039). And, in the lung function (FEV1 and PEF) and thoracic cage mobility, there was no significant between smoking group and non-smoking group. The correlation between nicotine dependence level and respiratory muscle thickness and lung function was no significant. Therefore, in their 20s male, smoking mostly did not have a structural and functional differences in the respiratory system. However, smoking is a major factor in reducing lung function, future study should be conducted on subjects with long smoking period or high nicotine dependence.