Physical activity for obstructive sleep apnea after stroke? A pilot study assessing the contribution of body fluids

Obstructive sleep apnea (OSA) and physical inactivity are common after stroke. Physical inactivity can lead to/or exacerbate edema following stroke, and the resultant overnight fluid shift may increase the risk of OSA. We aimed to investigate the effect of physical activity on nocturnal rostral fluid shift, sleep pattern, and edematous state of hemiparetic patients.

Neck circumference (tape measured) and arms, legs, and trunk fluid volume (bioelectrical impedance spectrum analyzer) were measured before and after 2 polysomnography (PSG) examinations. In the lab, a whole night PSG was performed after the intervention. The intervention consisted of inactivity (lying down and sitting) or activity (standing, performing calf muscle contractions while standing, walking, and climbing stairs) between 13 and 21 h, after the randomization of the participants. With a 7-day interval, participants crossed over to the other group.

From 126 eligible participants, 8 with hemiparetic post-first-ever ischemic stroke at the subacute phase were recruited (age: 53.2 ± 16.2; 6 women). Physical activity reduced AHI from 19 to 13 n°/h and wake after sleep onset from 76.5 to 60.3 min and increased fluid volume of paretic and non-paretic arms and trunk before sleep compared to inactivity.

An acute bout of physical activity reduced OSA classification based on AHI (from moderate to mild) and sleep fragmentation. Our results provide preliminary evidence of a possible link between physical activity in patients after stroke as an intervention to counteract OSA severity and improve sleep.