Sometimes they started when Esther Flinterman (54) got up in the morning and started making coffee in the kitchen. Boom. A break. And then, suddenly: boomboomboomboomboom. Heart beats. Maybe it was because she was so tired all the time. It must be through menopause, she thought. She could live with those palpitations. But she would rather get rid of that blanket of fatigue that weighed on her today than tomorrow.
During a holiday with her best friend on the Greek island of Skiathos, Flinterman noticed something strange: her traveling companion suddenly became more tired every day. We slept together in a hotel room. After a few days, my girlfriend was unstoppable. She was exhausted.’ After some insistence, the high word came out: Flinterman snored so loudly in her sleep that her friend lay awake for hours.
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Aliette Jonkers is a science journalist and writes for de Volkskrant on medical topics.
Flinterman did not yet link snoring to her physical complaints. ‘I found it most embarrassing. I am single and I started to worry especially about future new loves. How could I ever get a nice guy if I was snoring like a construction worker?’ That turned out to be not too bad, but when Flinterman was told that she not only snored but also stopped breathing regularly, she went to the doctor. The result of the sleep study that followed was crystal clear: with 53 breathing stops per hour, Flinterman had a severe form of sleep apnea.
The word apnea is derived from Greek and literally means ‘no air’. If the muscles in the pharynx relax during sleep, local soft tissue can collapse and partially or completely close the airway. Only when such breathing stops occur at least five times per hour and last longer than ten seconds, there is obstructive sleep apnea (OSA). There is also a rarer form, central sleep apnea (CSA), in which the control from the autonomic nervous system falters for a while, but it usually concerns OSA.
Oxygen level below safe limit
The oxygen level in the blood drops during a breath stop and then regularly drops below the safe limit of 90 percent. Women in particular often wake up with a fright. ‘It seems that women are watchful sleepers,’ says pulmonologist and somnologist Lisette Venekamp of the Kempenhaeghe expertise center. ‘We know that because we have more with women respiratory effort related arousals to see. These are sleep disturbances or accelerations in brain activity due to increased work of breathing. Men often just keep on snoring.’
In the short term, the body resolves the breathing pause itself. If the autonomic nervous system notices that the oxygen concentration in the blood is too low, it sounds the alarm with bells and whistles. The heart rate rises, as does blood pressure and muscle tension in the airways. Then breathing starts again.
In the long term, sleep apnea may increase the risk of high blood pressure and cardiovascular diseases, such as stroke, scientists think, although this has never been proven. However, after treatment with, for example, a special brace or a CPAP – a device that keeps the airways open with positive pressure – patients sleep better, feel fitter and suffer less from anxiety and depression.
The risk factors for the development of OSA are fairly well documented – reaching middle age, being overweight, alcohol and the use of sleeping pills are notorious – but no one knows exactly how many people suffer from frequent breathing problems at night. The Apnea Association estimates that six hundred thousand Dutch people have sleep apnea. The Dutch guideline Obstructive sleep apnea (OSA) in adults also states that the prevalence of sleep apnea in the general population is ‘essentially unknown’.
The thought that she might have sleep apnea had never occurred to Esther Flinterman. She is not the only one, as Venekamp learns. ‘Women often do not fit the classic image of the patient with sleep apnea: an overweight middle-aged man who snores and sometimes falls asleep spontaneously during the day. As a result, women don’t easily raise the alarm with their complaints.’
General practitioners and medical specialists also do not quickly think of sleep apnea if the patient in the consulting room is a woman, she knows. ‘This is because women more often have atypical symptoms, such as insomnia, restless legs, depression, nightmares and constant fatigue. Sometimes they walk around for years with misunderstood complaints. That entails a lot of extra suffering.’
Less complete breath stops
What makes diagnosis in women tricky is that the risk of sleep apnea increases with age. When levels of the female hormones estrogen and progesterone fall, the risk of sleep apnea also increases. As a result, women, like Esther Flinterman, quickly think of menopausal complaints, while their symptoms can also indicate sleep apnea.
To make matters worse, women also more often have a variant with less complete breathing stops. ‘We see hypopneas more often in women,’ says Venekamp. ‘The airway does not close completely, but there is a strongly reduced airflow. That is less noticeable to a partner than when someone suddenly stops breathing and after a while suddenly a noisy breath follows.’
And then there is another reason that women with sleep apnea complaints are overlooked in healthcare. Many doctors use the number of breath stops per hour (the Apnea Hypopnea Index or AHI) as a guideline to determine whether a person needs treatment. A misconception, says Venekamp. ‘The level of the AHI says nothing about the severity of sleep apnea when we look at the symptoms. Women are then told that sleep apnea cannot be the cause of their complaints, after which no treatment follows. It’s a real shame, because that’s not how they are treated enough.’
Esther Flinterman was immediately forwarded for investigation. With success: since she sleeps with a CPAP, the fatigue has disappeared. ‘I really feel reborn! I wake up fit and at work I can keep ten balls in the air again.’ Extra bonus: the palpitations are also a thing of the past.