Health. Sleep apnea: positive pressure ventilation reduces the risk of death

Obstructive sleep apnea syndrome (OSAS) is a condition in which the airways become temporarily blocked during sleep, resulting in low blood oxygen levels, frequent awakenings, and fragmented sleep. Studies show that this breathing disorder can increase the risk of premature death, as well as the likelihood of suffering heart problems or stroke.

The gold standard treatment is continuous positive airway pressure (CPAP): it helps reduce nighttime breathing pauses, daytime sleepiness, and improves quality of life . The principle? The CPAP machine sends a pressurized stream of air to keep the airways open during sleep, which prevents the soft tissues of the throat from collapsing, the main cause of respiratory arrest.

However, the impact of continuous positive airway pressure on the risk of death from any cause, and on serious cardiovascular and cerebral events, remained debated, as not all randomized controlled trials (the highest level of scientific evidence) reached the same conclusion.

Moreover, most studies included too few patients, too short a follow-up period and a generally low-risk patient profile (no excessive daytime sleepiness, few associated illnesses and less severe nighttime breathing problems). Patients at higher risk, such as those with significant daytime sleepiness, were often excluded from studies because there was a reluctance to follow them for a long time without offering them specific treatment.

This is why a systematic review existing studies has been carried out, and it has just been published: it examines randomized controlled trials but also non-randomized studies taking into account factors which could influence the results, around thirty in total, having included more than a million patients (1175,615, precisely).

So, is CPAP really effective in reducing overall mortality and cardiac mortality in adults with sleep apnea?

The results show that the risk of death from all causes and cardiovascular death is significantly lower in patients treated with CPAP compared to those who were not, over an average follow-up of 5.1 years. Specifically, the treatment reduced the risk of overall mortality by 37% and the risk of cardiac mortality by 55%. In addition, the benefits of the treatment were greater in patients who followed their treatment well (so-called compliant patients, generally the threshold is set at 4 hours of use per night).

This study, published in the Lancet on respiratory diseases, provides solid, if not decisive, evidence against the risks associated with sleep apnea . An essential piece of information to know and share with people on CPAP is that they should wear their device at night for as long as possible to maximize the benefits of the treatment.

Dr. Laurent Nguyen, a pulmonologist in Bordeaux and member of the board of the French Respiratory Health Association, explains: " For good compliance with CPAP treatment, it is recommended to use the machine for at least 4 hours per night. However, 5, 6, or even 8 hours of use are even more beneficial! Studies show that from 4 hours of use, the first clinical benefits appear, in the short, medium, and long term. The more patients use the machine, the more they notice an improvement in their syndrome, their sleep, and their overall quality of life ."