What if the quality of our nights predicted the moment of our death? This is the amazing discovery – worrying, some will judge – specialists from the sleep center at Stanford University in the United States. By providing an artificial intelligence algorithm with the night recordings of 12,000 subjects, these scientists first determined the characteristics of a normal night at a given age. Then they compared the “sleep age” of different individuals against this standard: “We have seen that those whose nights resemble those of older people tend to die prematurely”, summarizes the Pr Emmanuel Mignotthe Frenchman behind this work.
It’s hard to find a better illustration of the importance of our sleep. This one, however, has rarely been so abused. Smartphone, series, extended or staggered working hours, stores open later and later…, the opportunities to neglect our pillow are always more numerous. “It is estimated that a third of adults sleep, voluntarily or not, less than six hours a night and are chronically sleep-debted, compared to 25% only ten years ago”, notes Professor Damien Léger, head of the center. of Sleep and Vigilance at the Hôtel-Dieu (AP-HP). A threshold that is not insignificant: it has now been well demonstrated that closing your eyes so little increases the risk of depression, diabetes, high blood pressure and cardiovascular or Alzheimer’s disease, and makes you more susceptible to infections. viral.
The Covid epidemic has not helped: 71% of French people now complain about their nights, a percentage up ten points compared to the start of 2020, according to the Coviprev survey by Public Health France. “At the start, we thought it was purely reactionary, but we can clearly see that the situation remains very anxiety-provoking, with a succession of crises: epidemic, war, inflation…”, underlines Dr Marc Rey, president of the National Institute sleep and alertness. But all the experts know it: to sleep well, you have to be able to abandon yourself, let go, and therefore feel safe. The context is hardly favourable. Not to mention the collateral damage of confinements and telework. Disrupted rhythms of life, a tendency to move less: all this also affects the quality of our rest. “We arrive at very worrying statistics, and yet the public authorities are not implementing any concrete action”, regrets Professor Pierre Philip, former president of the French Society for Sleep Research and Medicine (SFRMS).
The essential rule: get up at the same time every morning
With his colleagues, he has long advocated for prevention messages to include sleep. “You should say eat, move, sleep, but even this simple change cannot pass,” regrets Professor Marie-Pia d’Ortho, head of the sleep center at Bichat hospital (AP-HP). The hope of these doctors, whose consultations are overflowing: that a general public campaign will remind the basics of good sleep hygiene. “Scientific studies show that this would solve a good part of the problems. Otherwise, we must fear a massive increase in anxiety-depressive disorders and possibly burnout in the months to come”, assures Professor Philip. Because the essential rule, the one acclaimed by specialists, remains largely ignored. Turn off the screens, go to bed at regular times, play sports, but not too late at night? It all counts, of course. But that’s not the main thing: “The most important thing is to get up at the same time in the morning, including on weekends, insists Sylvie Royant-Parola, the president of the Morphée network. It’s this regularity of getting up which will allow the good synchronization of all the rhythms and trigger the mechanics of sleep.”
Valuable advice in the event of temporary difficulties, but insufficient for the 15% to 20% of French people suffering from chronic insomnia. To fall into this category, you must experience difficulty falling asleep for more than thirty minutes, or wake up at least twice a night, or an hour or more before the alarm clock rings. And this at least three times a week, for more than three months, with an impact on daily functioning. An illness sometimes caused by other pathologies – sleep apnea, restless leg syndrome, great anxiety or depression – which must be treated elsewhere. But, sometimes, there is none of that: for some, sleep seems to have simply slipped away. “Who doesn’t sleep when I don’t sleep? What beast has eaten my sleep?” wondered Marie Darrieussecq in her book Not sleeping published in 2021 (P O L editor). To this question, scientists are finally beginning to provide answers – and to find treatments.
The more we look for Morpheus, the more he escapes
The key word now? “Hyperawakening”. Contrary to popular belief, the disruption of sleep mechanics (circadian cycle and homeostatic pressure, which can be defined as the energy level of the brain) does not seem to be solely responsible for these restless nights. Far from it, even. The progress of recent years, in genetics and brain imaging, shows that the culprits are more likely to be found in the circuits for managing emotions and awakening. A Dutch researcher, a great specialist in insomnia, even thinks he has discovered the biological substrate of this pathology. As he details in an extensive review published last year in the journal of the American Society for Physiology, this disorder “could be a disorder of the regulation of emotional memory during the night”, which would find its origin in abnormalities of brain functioning during REM sleep. The brain would continue to produce a neurotransmitter, norepinephrine, which normally stops during this phase. In summary, the brain of insomniacs would remain too alert, as if hyperactive, and would poorly manage emotions. A phenomenon accompanied by a background of anxiety, with ruminations which would contribute to fixing negative emotions on sleep, and would snowball: the more one looks for Morpheus, the more he escapes…
“We still don’t know if these disturbances are causal or if they are themselves a consequence of something else. But these advances reinforce the relevance of cognitive and behavioral therapies (CBT), whose effectiveness has already been well demonstrated. “, emphasizes Dr. Isabelle Poirot. These, in fact, promote the regulation of thoughts and emotions, and behaviors adapted to sleep.. Unfortunately, the offer is still limited and this treatment remains difficult to access. But advances in e-health should soon make them accessible to as many people as possible, thanks to applications based on artificial intelligence tools. However, these therapies do not work very well in cases of very severe insomnia. This is why many doctors are waiting for the arrival of a new class of drugs, called orexin receptor antagonists. Unlike sleeping pills currently on the market, which work by increasing sleep but prove ineffective beyond a few weeks, these products reduce wakefulness. “It will certainly be an interesting complementary tool, even if you have to be careful, as always with new molecules”, underlines Isabelle Poirot, who leads a working group responsible for updating the recommendations for the management of insomnia.
Another recent discovery concerns patients who until now were said to have “poor perception of their sleep”. They say they don’t sleep, and until recently doctors didn’t really believe them, because when their nights are recorded, they look perfectly normal. But several teams eventually realized that was not the case. “We reviewed with an artificial intelligence tool their sleep curves, which seemed at first sight quite similar to those of good sleepers. And, indeed, we discovered a whole series of small disturbances that we do not spot not usually, but which are close to what we observe in insomniacs”, reports Professor Léger, at the Hôtel-Dieu. At least now they will be taken seriously – until new advances make it possible to offer them, too, suitable treatments.