Influence of posture and gender on breathing pattern in healthy subjects: A three-compartmental analysis

Background: It is well known that posture influences breathing pattern, however a three-compartmental analysis is not yet available. The effect of gender is still controversial. Aims: To investigate the effects of posture and gender on breathing pattern during quiet breathing in three postures: sitting, supine and supine with trunk inclination of 45°, in healthy. Methods: 29 subjects(18 men and 11 women), aged 24±2 yrs, body mass index of 24±3 kg/m 2 and normal pulmonary function were studied. Evaluation was performed by optoelectronic plethysmography(BTS-Italy) in three different postures(59 each). The following variables were analysed: Chest wall tidal volume–V CW , respiratory rate-RR and contribution of the pulmonary rib cage–V rcp% , of abdominal rib cage-V rca% and of abdomen–V ab% to tidal volume. Statistical analysis was performed by Friedman test or ANOVA for repeated measures(postures). For the comparison between gender unpaired Student9s t or Mann-Whitney were performed, according to distribution. α was set at 5%. This study was approved by the Ethic Committee and subjects gave written consent form. Results: Table 1 shows the comparisons among postures. For gender, men showed higher V CW than women in supine position. Women showed higher V rcp % in sitting position while men presented higher V ab % in trunk at 45°. Conclusions: Our results showed that posture influence breathing pattern as well as gender.