Dual-energy X-ray absorptiometry analysis of body composition in patients affected by OSAS.

Obstructive sleep apnoea syndrome (OSAS) is a disorder characterized by recurrent episodes of apnoea. This study evaluates the body composition in OSAS patients compared to normal weight, pre-obese and obese subjects. Body composition has been measured by dual-energy X-ray absorptiometry in the whole body and in three different body regions. Abdominal region revealed no significant differences in fat mass percentage between patients and controls and no correlation between fat mass percentage and severity of OSAS. At the level of oral region, OSAS patients showed a significant decrease of fat free mass compared to control groups. At the level of neck region, OSAS patients showed a significant increase of fat mass compared to control groups and a significant correlation between the neck fat mass percentage and severity of OSAS. Regional fat distribution constitutes a risk factor for OSAS and a prognostic factor for severity of OSAS.