Sleep is important, everyone knows that. However, more than 936 million people worldwide suffer from obstructive sleep apnea, which immensely affects the quality of sleep. Three studies are now providing new insights into the health consequences of chronic snoring.

Sleep makes up a large part of our lives. On average, we sleep 219,000 hours – a third of our entire lifetime, assuming we live to be 75 years old. Nevertheless, most people struggle with sleep problems from time to time – and feel the consequences in their everyday lives in the short or long term.

However, if sleep disorders become chronic, it can even become really dangerous in the long run. These include, above all, unrecognized diseases such as obstructive sleep apnea – a breathing disorder in which breathing is regularly reduced or completely stopped during sleep due to a narrowing of the pharynx.

In Germany alone, 26 million people suffer from snoring. Men in particular are affected; women are usually spared until the menopause due to a different anatomy in the neck area.

The dangerous thing: The breathing pauses can occur several hundred times a night and sometimes last for minutes. This can lead to a drop in the oxygen concentration in the blood and a reduced supply to the organs. While this condition is not permanent, it can have numerous health consequences in the long run.

In addition, the sleep and recovery phases of those affected are immensely affected. When the oxygen concentration drops, the brain usually sounds the alarm – and wakes up the body. The various stages of sleep – for example deep and dream sleep – are disturbed and sleep is not restful.

Obstructive sleep apnea syndrome is usually characterized by the following symptoms:

Three different studies that were presented at the European Respiratory Society International Congress (ERS) in Barcelona (Spain) have now examined the health consequences of snoring.

The results summarized: Snorers tend to have an increased risk of mental decline, blood clots and cancer. This is especially true for people with obstructive sleep apnea.

The first study by the University Hospital of Lausanne examined 358 subjects aged 65 and over who were already part of two other ongoing studies – the CoLaus/PsyCoLaus and the HypnoLaus. A sleep test was first used to determine whether sleep apnea was present and, if so, how severe it was.

The researchers then examined the mental processing abilities of the subjects twice, each after five years. For example, they examined variables such as:

The result: Sleep apnea can be associated with an increased decrease in mental processing ability. The reason for this is in particular the low oxygen content during sleep due to sleep apnea, explains Nikola Marchi, head of the study.

What is striking is that the verbal fluency tests found a greater deterioration in the skills measured in people aged 74 and older and in men. The researchers emphasize that more research is needed to better understand why men seem to be more affected by mental decline.

Another study from France examined more than 7,355 sleep apnea patients over a period of six years. The aim was to examine the severity of sleep apnea and to link it to consequential health damage. Severity was measured using the following parameters:

104 of the subjects developed venous thromboembolism (VTE). Subsequent analysis of the study data revealed that patients with severe sleep apnea were twice as likely to develop a blood clot in the deep veins as those with less severe sleep disorders.

A third study examined the link between obstructive sleep apnea and the development of cancer.

In the first part of the research, the researchers compared data from almost 63,000 sleep apnea patients with data from the Swedish cancer registry. Potential influencing factors such as height, medical history and socioeconomic status were taken into account.

In the second part, the researchers then compared more than 2000 cancer patients with sleep apnea with more than 2000 sleep apnea patients without cancer. In the former, sleep apnea was documented up to five years before the cancer diagnosis. The scientists also examined the severity of sleep apnea using the apnea-hypopnea index (AHI) and the oxygen desaturation index (ODI)

The result: The cancer patients had slightly more severe sleep apnea than the non-cancer patients, with an average AHI of 32 versus 30 and an ODI of 28 versus 26. In a further analysis of subgroups, the ODI was higher in patients with different types of cancer:

According to the researchers, untreated obstructive sleep apnea can be considered a risk factor for cancer. In addition, the degree of oxygen deficiency caused by the respiratory disorder can be associated with cancer.

This is an important aspect, since it was previously assumed that the cause of the connection between sleep apnea and cancer was only indirectly related to the sleep disorder itself, but rather to the health consequences (obesity, cardiovascular diseases). A causal relationship between obstructive sleep apnea and cancer is now to be investigated in further research.

Winfried Randerath, head of the European Respiratory Society (ERS) for sleep-related breathing disorders, emphasizes the importance of the new findings: “These three studies show worrying associations between obstructive sleep apnea and important diseases that affect survival and quality of life. The data demonstrate the importance of sleep apnea for cancer, venous thromboembolism and mental health.”

Although more research is needed to prove a causal relationship, it is important that people with sleep problems are educated. If there is a justified suspicion or a diagnosis of obstructive sleep apnea, treatment is essential. So far, this has been based on the degree of severity of those affected and is usually discussed with a specialist.

In severe cases, regular positive airway pressure therapy may be necessary to relieve the narrow lung passages. In some cases, those affected also have to undergo an operation. Aids can also be used to influence the sleeping position, to fix the tongue or jaw or to improve nasal breathing. However, so far there is no well-founded evidence of the actual effect of these products.