Sleep apnoea is a condition where breathing repeatedly stops and starts during sleep. There is more than one type. In central sleep apnoea, the problem starts in the brain, often after neurological damage such as a stroke, and certain medications and alcohol can also play a part.
The most common type by far is obstructive sleep apnoea (OSA). Here, the muscles that keep the airway open relax too much and the airway collapses. Severe obesity makes this worse by adding pressure around the airway and chest. OSA affects around 5 to 10% of the population, and studies suggest that up to 80% of people with severe obesity have the condition.
Why sleep apnoea often goes unnoticed
Most people with sleep apnoea are not aware of the pauses in their breathing. It is usually a partner who notices loud snoring followed by silence, sometimes long enough to feel alarming, before breathing restarts with a gasp. The repeated drops in oxygen leave people feeling constantly tired, unrefreshed and foggy. Many notice headaches, exhaustion and poor concentration. In severe cases, people can fall into brief microsleeps during the day, which is especially dangerous when driving.
Possible health consequences
Sleep apnoea does more than disturb your sleep, as it puts strain on the whole body. OSA raises the risk of high blood pressure, heart failure, heart attacks and strokes. It is also linked to erectile dysfunction in men, depression and type 2 diabetes. Left untreated, sleep apnoea has a real effect on both physical and emotional health.
How sleep apnoea is diagnosed
If you think you may have OSA, the first step is to see your doctor. You may be asked about your symptoms and daytime sleepiness, sometimes using screening tools such as the Epworth Sleepiness Scale or the STOP-BANG questionnaire. To confirm the diagnosis, you may be offered a sleep study that measures your breathing, heart rate, oxygen levels and sleep patterns. In many cases you can take the monitoring equipment home to record overnight, though sometimes a night in a sleep unit gives the most accurate results.
Treatment options
When sleep apnoea is confirmed, CPAP is often the most effective treatment. You wear a small mask during sleep that keeps the airway open and prevents it from collapsing. After a short adjustment period, most people sleep better and feel far more energetic during the day.
In milder cases, a mouthguard that adjusts the jaw can help. Surgery may benefit certain people, especially where enlarged tonsils are adding to the blockage. Some people who only have symptoms when lying on their back find relief with devices that keep them sleeping on their side.
How weight loss surgery helps sleep apnoea
One of the best-documented benefits of weight loss surgery is the improvement, and in many cases the resolution, of sleep apnoea. As you lose a significant amount of weight, the pressure on your airway falls and breathing becomes easier. Many patients are able to reduce or stop using their CPAP within a few months, under the guidance of their sleep team. In one UK trial of gastric bypass patients, 70% had no sleep apnoea three years after surgery, compared with far fewer in those treated without surgery.
Sleep apnoea is just one of several conditions that can improve or even disappear after weight loss surgery, alongside type 2 diabetes, high blood pressure, joint problems and infertility.
