Abstract
Objective: Postural stability depends on the co-ordination of the central nervous system with visual sense, proprioceptive and vestibular information. Sleep deprivation has been shown to affect this function. The objective of this study was to assess the effects of sleep disordered breathing (SDB) on postural stability.
Methods: 158 subjects referred for suspected SDB had an overnight sleep study and were placed on a posturographic platform in the late afternoon. This platform allows measuring the center of pressure (CoP) oscillations and to calculate: total displacement of CoP in X and Y axis, mean surface and speed of CoP displacement, and the LFS ratio (length of CoP displacement x surface of CoP trajectory).
Results: 98 men and 60 women were included. Mean age ±SD was 45.4±5.5 y.o., BMI 27.5±5.6 kg/m2 and apnea-hypopnea index (AHI)13.6±16.1/h. AHI was < 5/h in 65 (41%) subjects, 5-15/h in 43(27%), 15-30/h in 30(19%), and >30/h in 21(13%). In patients with an AHI >5/h vs AHI<5/h, we observed an important increase in LFS (+21%, p<0.001), in XY length (+23%, p<0.001) and in mean speed (+ 23%, p<0.001). After controlling for age and BMI in linear regression models, there was a positive association between LFS and AHI (p=0.04) and negative associations between mean SaO2 and LFS (p<0.007), mean speed (p=0.01), and XY length (p=0.01), and a trend for an association between LFS and %time with a Sao2<90% (p = 0.07).
Conclusion: The severity of SDB and the related decrease in nocturnal SaO2 seem to affect significantly daytime postural stability.
- Copyright ©ERS 2015