[Influence of posture in respiratory function examination of obese subjects. I. In the healthy subject without ventilation disorders].

On earlier occasions healthy subjects, and chronic bronchopneumopathy patients were subjected to respiratory function tests in different postures using the plethysmographic and helium dilution methods. This protocol was then applied to a series of obese patients without the functional characteristics of alveolar hypoventilation identified in preliminary functional tests. The study revealed: a) non significant differences between plethysmographic and helium dilution findings; b) no significant volumetric differences produced by different postures (standing or squatting) especially as far as Total Lung Capacity is concerned. These results confirm the findings of others (Sharp et al., 1986) that diaphragmatic adjustment to changes in posture is inadequate in the obese even in the absence of hypoventilation.