Influence of sex on diaphragm thickness using a method for determining intima media thickness in healthy young adults
Abstract Background: To clarify the differences in diaphragm thickness between male and female participants in healthy young adults using ultrasonography and to investigate the relationship between diaphragm thickness and respiratory pressure.Methods: Twenty-nine healthy individuals (16 females and 13 males) participated in the study. Diaphragm thickness was measured at total lung capacity (TLC) and at functional residual capacity (FRC) in each participant. We measured the diaphragm thickness using a method for mean intima media thickness. Moreover, change ratio of diaphragm thickness was calculated with the diaphragm thickness at TLC and FRC.Results: Mean diaphragm thicknesses at FRC in males were significantly narrower than those in females (p<0.001). The change ratio of diaphragm thickness was significantly augmented in males compared with that in females (p<0.001). There was a significant positive correlation between the change ratio of diaphragm thickness and respiratory muscle strength in males but not in females.Conclusions: The change ratio might be an alternative to evaluate respiratory muscle strength in young adult males. The diaphragm thickness values and the change ratio of diaphragm thickness in healthy young adults, evaluated by B-mode sonography, were varied based on sex.