In France, between 4% and 10% of the population, depending on age, suffers from sleep apnea syndrome according to figures from the French Society for Sleep Research and Medicine. In these patients, the throat muscles relax and block airflow into the lungs. This syndrome is manifested by repeated interruptions of breathing during sleep. A phenomenon that causes daytime sleepiness, significant fatigue, concentration problems, cardiovascular complications. But not only.
According to a recent study by researchers from the UK, Germany and Australia, sleep apnea could also cause early cognitive decline, even in healthy, non-obese patients. These findings were published in the scientific journal Frontiers in Sleep. “We show poorer executive functioning and visuospatial memory and deficits in alertness, sustained attention, and psychomotor and impulse control in men with OSA. Most of these deficits were previously attributed to comorbidities,” said Dr Ivana Rosenzweig, a neuropsychiatrist who heads the Sleep and Brain Plasticity Center at King’s College London and lead author of the study. In the release of this study, she underlines that, for the first time, it is established that this syndrome could impact social cognition.
This study was conducted with a group of 27 men between the ages of 35 and 70. All suffered from sleep apnea but none had comorbidities. Generally, age is a risk factor for sleep apnea. Similarly, overweight and obesity are also risk factors. “The appearance of fatty deposits along the pharynx, leading to a narrowing of the airways and a decrease in the volume of the respiratory tract, explains this association”, details Inserm.
According to the results of this study, patients with sleep apnea had lower alertness, executive functioning, short-term visual recognition memory, and social and emotional recognition than the control group where men did not. did not suffer from this syndrome. “Patients with mild OSA performed better in these areas than patients with severe OSA, but worse than controls,” the study adds.
“The most significant deficits…were demonstrated in tests that assess both simultaneous visual matching ability and short-term visual recognition memory for non-verbal schemas, tests of executive functioning, and change of mind. attentional set, alertness and psychomotor functioning, and finally, in social cognition and emotion recognition,” the authors list. Before concluding: “OSA is sufficient to cause these cognitive deficits, which previous studies have attributed to the most common comorbidities of OSA, such as systemic hypertension, cardiovascular and metabolic diseases and type 2 diabetes. »
For the moment, complicated to establish a clear link between sleep apnea and cognitive decline. In the findings of the study, the researchers suggest that cognitive deficits are the consequence of intermittent low oxygen and high carbon dioxide in the blood, changes in blood flow to the brain, sleep fragmentation and neuroinflammation in these patients.
