The Role of a Wearables-track Tele-exercising Program on Cognitive Function and Brain Oxygenation in Patients With Obstructive Sleep Apnea

Background: Obstructive sleep apnea (OSA) is characterized by repetitive episodes of obstruction of the upper airway during sleep and leads to intermittent hypoxia, sleep fragmentation, hypercapnia and sympathetic hyperactivity which are associated with multiple adverse effects on health, in particular with brain health. Hyperarousability in OSA has a negative impact on sleep in the macro- and micro-architecture and sleep continuity, both of which are important players in neurogenesis, brain plasticity, alertness, and memory formation and consolidation. Thus, chronic sleep changes caused by OSA could negatively affect cognitive health. Both sleep fragmentation and intermittent hypoxia interfere with brain structure and function, increasing their vulnerability to neurodegenerative diseases. The prevalence of OSA is increasing as it is conjoined with obesity and it tends to elude clinicians' attention, as in only 10% of the population the definitive diagnosis can be established. Almost 80% of OSA patients report declining performance at work while 40% of dementia risk is attributable to modifiable risk factors such as physical inactivity.

Exercise offers a wide variety of benefits for the general population as it improves the cardiopulmonary, and metabolic profile. In addition, exercise is recommended as a low-cost, easily administered, and non-pharmacologic intervention, with positive effect on brain health and cognitive function, mainly by improving the sleep architecture, by enhancing the neurovascular oxygenation process and cerebral oxygenation, by reducing sympathetic overactivity and improving vascular function at rest and during exercise or mental stress. Finally, it has been shown that exercise can counteract the many aspects of decline in the brain's environment, such as the reduced blood flow and the lack of important factors (i.e. brain-derived neurotrophic factor-BDNF) that nurture brain neurons and encourage the growth and development of new neurons and synapses.

Therefore, long-term exercise providing the greatest and longest-lasting benefits e.g. increase cerebral neurovascular dynamics as assessed with functional Near-Infrared Spectroscopy (fNIRS) method and the intensity of exercise being related to cognitive functions such as improve memory after 12-week aerobic exercise and exercise with resistances. The effectiveness of different physical activity programs has not been properly established and some studies suggest that supervised versus self-selected programs might have similar results. In addition, the types of exercise programs in patients with sleep disorders have been addressed in literature. However, it has been noted that compliance in supervised programs in particular those lasting several weeks can often be an important limitation of the studies. Tele-exercising could be a key to overcome this important limitation, however, data on tele-exercising seems to be scarce.

Purpose: The main goal of the study is to explore the impact of a 12-week tele-exercising program on the cognitive profile as well as on specific parameters of brain functions, brain metabolism and brain oxygenation in patients with obstructive sleep apnea, thus highlighting the multidimensional relationship between physical exercise, cognition and brain oxygenation/metabolism. We will therefore apply a 12-week, wearable-track, tele-exercise intervention in patients with a Sleep Apnea Syndrome with and without cognitive impairment and compare the groups outcome on cognition and brain metabolism.

The primary aim of this study is to investigate the extent to which tele-exercise improves cognitive functions in patients with OSA.