Objective: Pulmonary disease is a common cause of morbidity and mortality; however a large number of individuals remain undiagnosed. Reasons for this include the inconsistent use of spirometry and the inability to produce acceptable and reproducible results. Chest circumference measurements have been positively correlated with pulmonary function in healthy individuals and those with pulmonary pathologies, thus potentially offering an additional method for assessing pulmonary function. Regular participation in endurance activities appears to increase VO2 max and the strength of the respiratory muscles. Thus, the aim of the study was to determine whether a strong, significant correlation between chest circumference measurements and spirometry measures existed in a young healthy active population, and whether this relationship remained consistent with changes in physical fitness.
Methods: A total of 235 military recruits (136 male; 99 female; 18–28 years old) were recruited in the study. In weeks 1, 12 and 19 of the Basic Military Training (BMT) programme, each participant voluntarily participated in a testing session which included anthropometric measurements (height, weight and chest circumference), spirometry tests and the multistage shuttle run test. Overall 26 participants complied with all spirometry inclusion criteria and completed all measures in all three testing sessions. Parametric descriptive and inferential statistics were used. Alpha was set at 0.05.
Results: The correlational analysis showed weak and non-significant correlations (r<0.4) between chest circumference measurements and spirometry measures over the 19 weeks of BMT, except for a moderate, positive and significant correlation between FVC and ICC in the male sample (r=0.522; p<0.05) in week 12. Strong, positive and statistically significant correlations between FVC and VO2 max were observed in weeks 1, 12 and 19 (r=0.682, p<0.01; r=0.616, p<0.01 and r=0.697; p<0.01, respectively) and between FEV1 and VO2 max in week 1 and week 19 (r=0.628; p<0.01 and r=0.658; p<0.01, respectively). A moderate, positive and statistically significant correlation between FEV1 and VO2 max in week 12 (r=0.554; p<0.01) was noted. There were no statistically significant changes in chest circumference measures over time (p=0.401). Statistically significant changes in FVC between week 1 and week 12, week 1 and week 19 and week 12 and week 19 (p=0.021; p<0.001 and p=0.025, respectively) were observed, as well as in FEV1 between week 1 and week 12 and week 1 and week 19 (p=0.027 and p<0.001). There were no statistically significant changes in FEV1/FVC between all testing sessions. Changes in VO2 max were statistically significant between week 1 and week 12 and week 1 and week 19 (p≤0.001 and p≤0.001, respectively). When controlled for by gender, the overall changes in FVC, FEV1 and relative VO2 max remained statistically significant (p=0.001; p=0.002 & p<0.001, respectively) and FEV1/FVC remained statistically non-significant (p=0.806).
Conclusion: This study did not find a statistically significant correlation between chest circumference measurements and pulmonary function, despite the statistically significant increase in the VO2 max; thus the hypothesis that chest circumference measurements could be used as a measurement of pulmonary function in a young healthy active population was not supported. Future research should be aimed at exploring this relationship using a larger sample.