Context

Sleep is one of the drivers of health trajectories and is clearly associated with physical, mental, and neurobehavioral well-being.

Multiple aspects of sleep have been associated with poor health outcomes and should therefore be included in the assessment of health trajectories. The average adult’s need for sleep is 8 hours per 24-hour cycle. The quality of sleep prior to any activity is the most prominent factor that influences the waking state and the level of alertness. Sleep duration strongly impacts diabetic, cardiovascular and weight trajectories, with greater increase in weight in those with habitual sleep deprivation. Besides the quantity of sleep, the quality of sleep is fundamental. If sleep is impaired due to inappropriate sleep hygiene or disease, this leads to sleep fragmentation. The quality of sleep is influenced by, among other things, sleep disorders namely sleep apnoea and insomnia. Poor sleep quality induces day-time fatigue, impaired alertness, and unproductivity at work. Moreover, insufficient sleep and/or sleep fragmentation have been linked to the development and modification of the trajectories of several chronic diseases and conditions, including type 2 diabetes, cardiovascular disease, obesity, and depression.

Sleep apnoea is both a disease and an exposure modulating health trajectories.

Sleep apnoea (SA) is a sleep-related breathing disorder characterized by repeated complete (apnoea) or incomplete (hypopnea) cessation of airflow during sleep. With nearly one billion people affected worldwide, sleep apnoea is one of the most preeminent non-communicable diseases. Sleep apnoea impairs quality of life because of poor sleep quality and induces daytime sleepiness. The usual treatments for obstructive sleep apnoea, Continuous Positive Airway Pressure (CPAP), and Mandibular Advancement Devices (MAD), are highly effective in maintaining the patency of the upper airways, preventing them from collapse and normalising breathing. Despite this effectiveness, there are two major issues. No treatment currently exists that can definitively cure sleep apnoea, which positions sleep apnoea as a long-lasting chronic disease which is a severe burden for the society.

In France around 40% of patients stop treatment after about 3 years...

...which means that these patients will face the impact of intermittent hypoxia and sleep fragmentation over the rest of their lives. Therefore, patients require regular long-term follow-up by a specialised health professional. Exposure to the recurrence of apnoeas during sleep, lasting more than 10 seconds each and repeated many times per hours every night over many years leads to chronic intermittent hypoxia which is a risk factor for the occurrence and aggravation of many cardiometabolic diseases (hypertension, ischemic diseases, heart failure and diabetes).

Sleep apnoea and intermittent hypoxia are considered as independent factors impacting health trajectories.

Indeed, as an example, sleep apnoea and chronic heart failure are closely entwined. We recently illustrated in a chronic heart failure cohort how sleep apnoea subtypes impact on individualizing latent classes (homogenous patient’s subgroups) which exhibit different prognosis trajectories. Sleep apnoea and more broadly sleep impairment have been shown to impact trajectories of type 2 diabetes through alteration in glucose metabolism. Therefore, the value-based management of sleep apnoea patients is the perfect condition for studying health trajectories and developing tools and interventions to curve these trajectories towards a better prognosis.