Each night, thousands of Australians stop breathing – sometimes with potentially serious ramifications. Find out what causes sleep apnoea, and how to manage it.
Snoring loudly enough to wake the dead? Getting up during the night to urinate? Exhausted during the day despite plenty of night-time kip? Chances are that these seemingly unrelated factors have a common thread – sleep apnoea. Sleep apnoea is a condition in which a person stops breathing during sleep. For the word lovers among you, ‘apnoea’ is adapted from the Greek word apnoia, derived from apnous, meaning ‘breathless’.
How does it develop?
“When you’re awake and breathe in, your muscles tense up and stop the throat from closing,” says Dr Christopher Worsnop, respiratory and sleep physician in the Department of Respiratory and Sleep Medicine at the Austin Hospital in Melbourne. “When you sleep, the muscles relax and the throat collapses a little.”
If the muscles relax too much, or your throat is very narrow to begin with, it can collapse further. The air you breathe in becomes turbulent and produces a vibration in the throat tissues, creating the dulcet tones of snoring. If your throat collapses even more, the lungs may not get enough oxygen.
The brain realises there’s something wrong, so it wakes itself briefly from sleep to get the throat muscles working again. Experiencing apnoea episodes is not unusual. However, the number and/or length of nightly episodes can determine whether the condition is serious enough to interfere with your quality of life and, in the longer term, affect your health.
Depending on the severity of your condition, symptoms can include:
- poor night-time sleep quality
- extreme day-time sleepiness
- loss of concentration
- slow reaction times
- poor memory
- impotence (a number of studies show a correlation between sleep apnoea, reduced circulation of testosterone and erectile dysfunction).
Night-time urination (nocturia) can also be a symptom. The bladder normally makes less urine during sleep. But if you wake frequently, your bladder makes daytime amounts, so you have to visit the bathroom. In a 2009 study of more than 1000 American sleep apnoea sufferers, around 85 per cent reported nocturia.
At its most serious, sleep apnoea can cause a dangerous drop in oxygen levels. “Every time you wake up to restore breathing, your body releases adrenalin,” says Dr Worsnop. “Consequently, your pulse rate and blood pressure shoot up. Over time, this could put you at greater risk of high blood pressure, heart attack and stroke.”
Click NEXT to find out if you in the high risk group and how sleep apnoea is diagnosed and treated
Who’s most at risk?
If you’re obese, you stand a higher risk of sleep apnoea. Obesity adds internal fat as well as external fat around the throat. “Excess internal fat can narrow the throat, so the muscles have to work harder to keep it open,” says Dr Worsnop. Age is another risk factor, because the throat muscles tend to relax more as you get older. Having a small lower jaw or overbite can also increase your risk. Men stand a greater chance of sleep apnoea, because they tend to have narrower throats. According to Nat Marshall, sleep researcher at Sydney’s Woolcock Institute, sleep apnoea in people aged over 30 is around three times more prevalent in men than women.
This ratio continues until menopause, when the incidence evens out. “Being a woman of childbearing age, or on hormone replacement therapy, seems to offer some protection against sleep apnoea,” he says, “although the link is not well understood.”
How is it diagnosed?
Many sleep apnoea sufferers are reluctant to have their symptoms investigated. If they don’t remember waking during the night, they may not believe anything is amiss. “If they’re a truckie, or do another job that requires being well rested and alert, they may worry that their boss could find out and they could lose their job,” says Dr Gerard Kennedy, senior psychologist at the Departments of Respiratory and Sleep Medicine at Austin Hospital and Monash Medical Centre.
That’s why it often takes repeated expressions of concern from their long-suffering partner to get the ball rolling. First stop is the family GP, who can refer the sufferer to a respiratory or sleep specialist. Then comes an overnight sleep study, to measure the duration and frequency of sleep disturbances.
Whilst sleep apnoea can’t be cured, there are ways to keep your airway open while you sleep. If you have a mild form of the condition that only occurs when you’re sleeping on your back, a tennis ball placed in the back pocket of your pyjama pants may prompt you to roll onto your side.
If you have a mild to moderate case, and the positioning of your jaw is the culprit, a ‘mandibular advancement splint’ may be appropriate. A bit like a sports mouthguard, it’s custom-fitted by a dentist. It works by repositioning the lower jaw forward, creating more room in the throat and allowing you to breathe freely.
Moderate to severe cases of sleep apnoea generally respond best to a Continuous Positive Airway Pressure (CPAP) machine, which uses a face mask to deliver pressurised air from the surrounding room environment. The air pressure goes into the back of your throat and stops it from collapsing. “CPAP technology works with pretty much everybody,” says Dr Worsnop. “It’s considered the gold standard for sleep apnoea treatment.”