Attenuation of Obstructive Sleep Apnea and Overnight Rostral Fluid Shift by Physical Activity

摘要

Physical activity attenuates obstructive sleep apnea (OSA) severity, as assessed by the frequency of apneas and hypopneas per hour of sleep (i.e., the apnea/hypopnea index [AHI]), even in absence of weight loss, but the underlying mechanisms remain unknown (1-3). Overnight fluid shift from the legs into the neck has been indicated as a contributor to OSA (4). We have previously shown that prevention of fluid accumulation in the legs, obtained by wearing compression stockings during the day, reduces the AHI by attenuating overnight fluid shift (5, 6). Moreover, intensified diuretic therapy reduced the AHI in proportion to the decrease in overnight fluid shift (7). Fluid accumulation in the legs is promoted by sedentary living (8, 9) and is counteracted by physical activity, which activates the musculovenous pumps (8-10). We hypothesized that 1 week of two periods a day of 45 minutes of moderate-speed walking will reduce the AHI in non-severely obese sedentary subjects with moderate to severe OSA by decreasing overnight fluid shift around the pharynx. Some of the results of this study have been previously reported in the form of an (11).