Sleep apnea: small breathlessness with serious consequences

An incessant pounding clamor harassed Mr. Pickwick’s lodgings. Once the door was opened, the figure of an extraordinarily fat boy was seen standing with his eyes closed as if he were asleep because of his expression of calm and repose. Asking him what he was coming for, he said nothing to himself, but he nodded once appearing to snore slightly; repeating the question three times elicited no response. When he was about to close the door on him, he abruptly opened his eyes, blinked several times and raised his hand in a gesture of knocking again».

This brilliant staging by the writer Charles Dickens in chapter 54 of his work The Posthumous Papers of the Pickwick Club went down in medical history as the original description of obstructive sleep apnea (OSA). Fat Joe, the chubby, rosy, sleepy, slow-thinking boy (in medical terminology, bradypsychia), magnifies and summarizes the main clinical findings of this widespread disease.

Fat Joe, the character in Charles Dickens’s ‘The Pickwick Papers’, probably suffered from obstructive sleep apnea.

Widespread but underdiagnosed: Although it is estimated that it affects between 5% and 8% of the population, there are many cases that do not come to light. And those affected can suffer serious repercussions, since other ailments (comorbidities) such as diabetes and cardiovascular disorders are associated with it.

And how can we know if we suffer from OSA? We must be attentive to these signs: strong and irregular snoring, which alternates with respiratory pauses (apneas) due to collapse of the airway; sleep that is not restful and usually interrupted by multiple awakenings; excessive sleepiness during the day; slow to formulate thoughts and ideas, as happened to Fat Joe; difficulty concentrating and memorizing; headaches, mainly suffered in the mornings; and nocturia, that is, the need to get up to urinate several times at night.

OSA and obesity: the chicken or the egg?

Multiple epidemiological studies suggest an association between sleep disorders (including lack of rest) and obesity, which is one of the epidemics of the 21st century. Logically, OSA is the most prevalent type of obesity related to sleep disorders.

But the relationship seems bidirectional. On the one hand, obese patients, especially those suffering from so-called central-type obesity (with a pear-shaped or piriformis morphotype, like Fat Joe), present OSA in a percentage that exceeds 50%; on the other hand, 60-70% of people with OSA have this excess weight problem, and patients with sleep disorders are more likely to develop it.

This seems to be related to the hormonal and metabolic disorder that causes sleep apneas. Due to these interruptions in breathing, the production of leptin (hormone that produces satiety and increases thermogenesis or heat production) decreases and that of ghrelin increases, which stimulates appetite and the formation of adipocytes, fat cells.

That is, in these circumstances, the brain establishes a procedure to save energy, probably in the wrong way. To this is added the increase in the intake of foods rich in fats and sugars, and the decrease in physical activity.

And as if that were not enough, the metabolism of patients with OSA can develop resistance to the action of insulin, which in many cases will lead to diabetes mellitus.

vascular disorders

Another consequence of sleep apnea is the intermittent drop in blood oxygen produced by obstructive events. This causes brain activation with brain microarousals, which we have been able to observe in the studies we carry out in the sleep laboratory.

We somnologists interpret that these microarousals, in which the individual does not become fully awake, represent a defense mechanism of the sleeping brain against an attack. Produced by the release of catecholamines (adrenaline), in the long term they increase the risk of suffering from arterial hypertension, angina pectoris, myocardial infarction, stroke, sudden death…

It should be clear that early detection of OSA and effective treatment are a powerful weapon of prevention against cardiovascular and cerebrovascular accidents. A simple overnight test in the patient’s home, such as respiratory polygraphy, can confirm or rule out the diagnosis.

Daytime sleepiness: danger of accident

The poor quality of night rest in patients with apnea has another fundamental connotation. Fragmented, superficial sleep, with multiple micro-arousals and brief wakes (to which nocturia must be added) mean that this sleep is not restful, with the consequent excessive sleepiness during the day.

The consequence is low intellectual performance, with difficulties in the ability to concentrate, memorize, solve problems, etc. And if these attacks of sleep attack us while driving, there is a serious risk of having a traffic accident.

In fact, the General Directorate of Traffic associates daytime sleepiness with up to 30% of accidents. These are also usually the most serious, since they occur at high speed, without prior braking and with a frontal impact. Suffering from sleep apnea increases between 3 and 7 times the chances of suffering traffic accidents, an estimate that increases to 11 times if, in addition, alcohol is ingested.

As expected, OSA also increases the risk of accidents at home and at work. In the latter case, it increases by at least 50%, which implies that the diagnosis and treatment of obstructive sleep apnea would prevent between 18,000 and 25,000 occupational accidents per year.

A mechanical aid to remove the obstruction

And how can it be treated? The main technique against moderate or severe disease is based on applying a nocturnal ventilation system using a compressor and an attached mask, which insufflates purified air (CPAP-BIPAP devices). This exerts positive pressure on the airway and allows the obstruction to be relieved during sleep. Some selected cases can also be solved by surgery.

However, it should be noted that the best treatment for OSA is weight loss, adopting a healthy lifestyle and following basic sleep hygiene rules.

This article has been published in ‘
The Conversation‘.