Background: Alterations of the sleep-wake cycle may lead to the development of hypertension, diabetes, cardiovascular disease, depression and anxiety. However, this association may be biased by obstructive sleep apnoea; which has not been commonly investigated as a confounder. The aim of this study was to compare actigraphy-recorded data and common comorbidities in patients with and without OSA.

Methods: We included 118 patients who had a cardiorespiratory polygraphy (n=48) or polysomnography (n=70) to diagnose sleep disordered breathing and a 2-week actigraphy to explore behavioural aspects of their sleep related symptoms. Comorbidities were captured based on medical records and medications.

Results: 52 patients were diagnosed with OSA. They had a higher prevalence of diabetes (12 vs. 2%, p=0.02) and cardiovascular disease (10 vs. 2%, p=0.04) and spent less time in bed (500±88 vs. 528±84 minutes, p=0.04) vs. controls; however, there was no further difference in any of the other comorbidity or actigraphy parameter. Whilst in control subjects, prolonged sleep latency was related to anxiety (30±27 vs. 20±27 minutes, with and without anxiety, p=0.04) and hypertension was associated with lower sleep efficiency (76±6% vs. 82±7%, p=0.02); no significant relationship was found between markers of sleep-wake cycle and comorbidities in patients with OSA.

Conclusions: Altered sleep wake cycle may be associated with comorbidities; however, this association seems to be affected by OSA. We suggest that OSA need to be considered when conducting studies on sleep wake cycle as well as mental and physical health.