Patterns of physical activity in Obstructive Sleep Apnoea and their association with sleepiness.

Objectives: Excessive daytime sleepiness (EDS) is a key symptom of Obstructive Sleep Apnoea (OSA). Both EDS and OSA affect, and are affected by, physical activity (PA). This study explores physical activity patterns in OSA patients and the association between activity and EDS.

Methods: This is a retrospective analysis of cross-sectional data from the Sydney Sleep Biobank, which recruited sleep clinic patients between August 2018 and June 2022. Participants aged > 18 years with untreated OSA were included, while those with other sleep disorders or whose medication/work affected sleepiness were excluded. PA was assessed with the International Physical Activity Questionnaire (IPAQ), with intensity quantified by metabolic equivalent of task (MET). Subjective daytime sleepiness with quantified by the Epworth Sleepiness Scale (ESS).

Results: Of 487 patients with OSA, 21% reported low (< 600 MET-min/week), 32% medium (600-2999 MET min/week), and 47% high PA ( > = 3000 MET-min/week). Participants with mild OSA were the most likely to be in the high PA group. ESS was not significantly associated with physical activity nor OSA severity, after adjustment for sex, age, body mass index, and sleep duration. Consideration of a potential interaction between physical activity and OSA severity did not change these results. However, in subgroup analysis of women only, severe OSA and medium and high levels of PA were linked to higher ESS scores.

Conclusions: Greater physical activity was associated with higher daytime sleepiness in women, but not men. However, further research is needed to reproduce these findings using objective measures of physical activity and to examine if physical activity has direct benefits for daytime symptoms of OSA beyond sleepiness.