The impact of body weight changes on body posture dominance in adult obstructive sleep apnea patients

Abstract

The aim of this work was to assess the relationship between changes of body posture dominance and changes of body weight over time in obstructive sleep apnea (OSA) patients. The participants were 112 nontreated adults with OSA who underwent two polysomnographic evaluations within an average of 6.2 years, at our sleep disorders unit. Positional patients (PP)””having most of their breathing abnormalities in the supine posture and who became non-positional patients (NPP)””had a significant gain in weight and a significant increase in apnea-hypopnea index (AHI), mainly in lateral AHI. On the contrary, NPP who became PP had a significant decrease in weight and showed a significant improvement in AHI, again mainly in lateral AHI. These NPP who became PP had initially a less severe disease as judged by AHI, lateral AHI, and minimum SaO2 during non-REM sleep and were less obese than NPP who remained NPP. The latter patients, who showed initially the worst disease, were more obese than the rest of the patients, and their condition did not change significantly over time. NPP who converted to PP showed a decrease in body weight and improvement of OSA, while PP who converted to NPP showed an increase in body weight and worsening of OSA. It appears that body weight changes have a modulatory effect on positional dominance, and lateral AHI appears to be a sensitive parameter of these changes.