A study conducted in the United States has shown that there is a cause-and-effect relationship between sleep apnea, a condition characterized by repeated interruptions of oxygen flow to the lungs while the patient is asleep, and the development of minimal cognitive impairment (MCD).

DCM - and the loss of memory it implies - had always been considered a condition inexorably linked to the process of aging, and even episodes in which the person is unable to remember a name, or the place where he has saved an object, for example, are called 'senile lapses'.

The successive interruptions of breathing caused by apnea can reduce oxygen levels in the patient's brain, which results in structural changes in the brain and alters the cerebral microcirculation. Therefore, recent research seeks to clarify the possible link between the lack of oxygenation suffered by the brain of people with apnea, and the development of memory disorders.

In five years, 45% of women who had apnea had developed minimal cognitive impairment, compared to 31.1% of those who did not have any respiratory problems

In the North American study, 300 elderly women participated who did not have memory problems at the beginning of the investigation. However, a third of these women did have a breathing disorder during sleep, which the researchers established in 15 or more episodes of apnea or hypopnea for each hour of sleep.

The authors of the work monitored the volunteers for five years and found that 45% of those with apnea had developed DCM, compared to 31.1% of those without breathing problems.

Although certain pathologies such as Alzheimer's disease, Parkinson's disease or amyotrophic lateral sclerosis, can cause central sleep apnea -an uncommon variety of apnea-, Dr. Diego García Borreguero, president of the Spanish Sleep Society, explains that this study shows that respiratory disorders are 'the cause, and not the effect of cognitive decline'.

Experts point out that apnea should be considered a risk factor to develop cognitive deterioration and that, therefore, it is essential that the diagnosis of apnea is made as soon as possible, because a proper apnea treatment would reduce the chances of the patient develop cognitive impairment.

Source: Spanish Dream Society

The Relationship Between Sleep Apnea and Cardiovascular Disease (November 2019).