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Wake-up call: The dangers of sleep apnoea

Nodding off in a meeting is not normal. Yet that – and more serious health effects of lack of sleep – are set to multiply along with obesity.

sleep, Wendy, mask Wendy Smith: Previously, “if I was driving to Auckland, I would have to stop and walk around and slap myself”. Photo/Simon Young

Wendy Smith stopped breathing for more than 80 seconds. She wasn’t choking, unconscious or underwater. She was asleep.

“My husband suffered the most because of my snoring,” says Smith, who endured sleep problems for three years. “And it slowly got worse and worse.” Her husband, with whom she runs a kiwifruit orchard in the Bay of Islands, started timing the non-breathing periods, which would always be terminated by her gasping and choking. Some lasted as long as 30 seconds. “In January this year he moved into the spare room. He just couldn’t stand it any more. I thought, obviously there’s something seriously wrong.”

In April she booked into an Auckland sleep clinic. Many people with sleep disorders can monitor their sleep at home, but Smith was asked to do the overnight sleep test, in which she was filmed and her brain waves recorded. When she was supposed to be in the most relaxed part of sleep, she had her longest period without breathing: 81 seconds. “Which is a hell of a long time.”

 

A DANGEROUS GAME


Smith’s overnight test revealed that she was only getting about 12% of deep sleep. “During the day, I was working fine and could function quite normally, but if I sat down I could close my eyes and go to sleep. No matter what time of day, anywhere, any place. If I was driving to Auckland, I would have to stop and walk around and slap myself.”

Smith was diagnosed with obstructive sleep apnoea, which occurs when the soft tissues of the throat close up and temporary block breathing. Aware that apnoeas reduce the level of oxygen to the brain, she quips: “I had an excuse why my brain wasn’t functioning properly.”

But conditions like apnoea can be deadly, putting strain on the respiratory and circulatory systems. They encourage an inflammatory state, says sleep expert Dr Andy Veale, increasing the risk of hardening of the arteries, heart attack and stroke. Research suggests low oxygen levels might accelerate cognitive decline as we age.

Although it is difficult to tease it out from co-morbidities such as obesity and high cholesterol, those who sleep less generally tend to experience ill health and conditions such as depression more than the rest of the population, are more likely to gain weight and don’t live as long, says Veale. There’s a U-shaped distribution of survival in terms of sleep times, he says: those who slumber for shorter and longer periods than the typical 7.5-8.5 hours die sooner.

Yet the problem, says Veale, is that we’ve become so used to being tired that our idea of what’s normal changes. “You look around at your friends and they nod off in meetings, and yet when I give talks to Rotary clubs and say it’s never normal to nod off in a meeting and it’s never normal to nod off in front of television, you see everybody just looking at each other. Because it’s such a common thing that we don’t think of it as abnormal.”

Nasal surgery might have been an option for Smith, but it’s “pretty unpleasant”, she says. So she went on a CPAP machine, a device that uses air pressure to keep the airway open. “And instantly I was 100% better.” She is pragmatic about the discomfort. “You have to make up your mind whether you want to deal with the problem or not,” says Smith. “In my case, I said, this is the treatment and if I’m going to have good health and good sleep and a happy husband, I’m going to do this.”

Sleep apnoea comes in three forms. Obstructive sleep apnoea is the most common. Central sleep apnoea occurs when the brain’s respiratory control system goes awry. The third variety is a blend of the other two. It’s estimated 4-8% of the working-age population have obstructive sleep apnoea. Five per cent of Auckland’s 1.2 million population is 60,000 people, yet there are 12 inpatient beds in the city, and perhaps another dozen in the rest of the country.

Sleep disorders such as apnoea have huge but often overlooked effects on our health and society. Sufferers tend to be sleepier during the day, so their concentration drops, they are more forgetful, their decision-making gets worse and their risk of accidents at work and behind the wheel increases dramatically. It’s estimated 13% of work injuries are due to sleep problems. One study found that obstructive sleep apnoea increased the risk of crashing a vehicle by at least 20% and perhaps many times that.

Smith has never fallen asleep on the job, although she has nodded off while drinking a cup of tea. Luckily she was sitting at her table at home. Others have been known to fall asleep several times a day while driving, while handling 110kV power cables and even while riding a motorbike, says Veale.

“A milk-tanker driver I looked after years ago wrote off a truck and trailer unit with a full load of milk. And that cost the insurance company more than $400,000. And he just didn’t take a corner on a long straight road. He’d gone to sleep.”

 

A SLEEPLESS EPIDEMIC


sleep, Andy Andy Veale: the sleeplessness epidemic is “writing a disaster in 15-20 years’ time”. Photo/Simon Young

Veale, who splits his work hours between the private six-bed NZ Sleep and Respiratory Institute in Auckland’s Greenlane and the Counties-Manukau District Health Board, says the contributing causes of obstructive sleep apnoea are well known: excess weight, smoking, alcohol, age. It’s been with us forever. “Joe the fat boy in The Pickwick Papers clearly had obstructive apnoea.” But the obesity epidemic means it’s getting much worse.

Unfortunately, you may simply have been born with a predisposition for the condition. About 15% of people diagnosed with sleep apnoea who visit Veale’s clinic are of normal body weight or below. Some people suffer simply because of their body type and face shape, such as having a narrow face or large tongue.

“So thin Asian faces, either with a mid-face that’s set back, what we call mid-face hypoplasia, or an undershot chin, they’re just as likely to have sleep apnoea. Maori and Polynesians with a big tongue as part of their muscular physiology. The tongue’s just another muscle. Seventy per cent of gridiron players in America have obstructive sleep apnoea. They’re not fat, but they have enormous neck muscles and big tongues.”

Not until obstructive sleep apnoea became more recognised and treated did anyone start to realise the dreadful toll it was taking. When Veale was a hospital registrar, Polynesian men were dying in the wards in their thirties of cardiac disease. Studies have found that Maori are twice as likely to have sleep apnoea and to have it in a severe form.

Why does sleep apnoea happen? The unique ability of humans to speak is a contributing factor. “The upper airway, from the nose to the voice box, is floppy, because we have to be able to move it quickly to speak and swallow food. And the available space behind the palate and behind the tongue might be 3-4mm deep. So it doesn’t require much change, either because of weakness of the muscle or muscle bulk or fat compressing from the outside, to halve that diameter of the airway, which is a partial obstruction. And if it completely collapses, because it’s wet, it sticks together and completely obstructs. And it’s the effort of unsticking the airway that disturbs sleep, because the brain has to wake up momentarily to make the muscles restore tone and the airway.”

The two consequences of this, says Veale, are impaired sleep because of the need to wake up many times a night to prevent you dying, and the cardiovascular risks of dropping oxygen and the adrenalin surges that the body gets as a result of complete obstructions.

Not everybody suffers, because not everyone is overweight or has narrow breathing passages. “If you’re born with a big airway, you’ll be protected against provocations that might cause obstructions in other people.”

It generally gets worse with age. “But people haven’t clearly separated whether this is an effect of weight gain with age or a loss of muscle tone. And as we get older, lots of things can disturb our sleep that we wouldn’t have been disturbed by as teenagers. With teenage sleep, they have a larger proportion of slow-wave sleep. A bomb could go off, or you could vacuum a teenager’s room, when they’re in slow-wave sleep and they wouldn’t wake up. As you get older, the proportion of slow-wave sleep gets less and less. So environmental stimuli, like a partner turning over or snoring, start to disturb sleep quality.”

 

DETECTION AND TREATMENT


How do you spot the effects of sleep apnoea? Audible snoring, restlessness during the night and serious daytime sleepiness – falling asleep easily and having to concentrate on staying awake. People may wake up feeling as if they’ve not gone to bed. They may be irritable and lose interest in sex. Other indications are less obvious, says Veale. People stop going out in the evening and don’t like to drive without someone else being in the vehicle. We are good at finding excuses such as long hours and shift work, he says.

In children, look for frequent snoring or snuffling. Behavioural problems may be due to lack of sleep. “Quite a few children are hyperactive as their technique of staying awake.” And children who aren’t thriving, either physically or at school, should be evaluated for sleep apnoea.

Veale’s clinic, which is private but has contracts with Auckland hospitals and district health boards elsewhere, will typically do a simple home study if there are no other concerns about sleep disorders and there’s no indication of heart or lung disease. The sleeper wears a device that measures air flow and chest and stomach movement.

Because inpatient tests are recorded and brain waves are monitored, much more information is gathered. “In general, people of very high risk, who have come to attention because they’ve had an accident we would direct to an inpatient sleep study so we know that they’ve slept.” Some, such as those who must drive for work, have been known to persuade their partners to wear the devices during home monitoring.

sleep, Wendy With a $1600 CPAP machine, Wendy Smith is “100% better”. Photo/Simon Young

The most severe cases of obstructive sleep apnoea are best treated with CPAP machines. These devices can give nearly instant relief, but because they involve strapping a nose-cone to your head they can take a couple of weeks to get used to. Surgery may be an option, such as for adults with nasal disease or children with big tonsils or adenoids, says Veale.

It’s important to get the right size and learn to sleep with your mouth closed, says Smith. The machines aren’t cheap either. Hers cost about $1600. You can rent them and some can be supplied through the health system, but she’d rather have her own. “I’m 100% better. Whereas before I would wake up and think, ‘Argh, just stay in bed for another hour’, I feel totally rested when I wake up in the morning.”

Less severe forms of apnoea do well with dental devices, says Veale. These are generally mouth guard-type splints that bring the lower jaw – and therefore the tongue – forward in relation to the upper jaw, opening the throat. Other methods include neurostimulation, which involves stimulating the tongue or its nerves to cause it to contract into the front part of mouth. Research has also been done elsewhere on improving muscle tone in the throat and tongue, after it was noted that playing the didgeridoo apparently helps matters.

If your apnoea is mild, you may be able to treat yourself. Pillows can modify your head and neck position, as can soft collars. Train yourself to stay off your back – it closes the airways most effectively – or wear a “snore belt” with a tennis ball between the shoulder blades, says Veale. There are also lubricating sprays for the mouth that reduce tissue stickiness.

For some people, losing 10kg of weight can eliminate their symptoms or at least reduce snoring and sleepiness. Smith, who’s 62 but has always been active, had put on 10kg following major surgery on her shoulder. “I made all sorts of excuses why I shouldn’t move.” She’s since lost the weight and did try sleeping without the machine, but found the problem is not fixed yet.

 

HOW MUCH SLEEP?


“There’s a simple way of judging if you’re getting enough sleep or not,” says Veale. “If you can turn over in the morning and get back to sleep, then you had inadequate quality or duration of sleep the preceding night.” And if you regularly sleep longer during weekends, then you don’t get enough during the week. Veale admits he has had six hours’ sleep a night since he was a student, yet if he goes away on holiday he will typically sleep longer than seven hours. “So I’m chronically sleep-deprived.”

Acknowledging this, Veale has advice for sufferers that’s tempered with realism. “We all theoretically should lose weight, get more exercise, stop smoking, cut out the alcohol … and the Tui ad comes to mind. In clinical trials, there are individuals who are successful at that intervention and they will respond well. But as a population, it’s dreaming.”

First, there’s the problem of our 24-7 society. The length of time we sleep has become shorter. We take sleeping tablets, which exacerbates the problem. Sitting in front of TVs and computers doesn’t help, says Veale, as they produce blue light, which suppresses melatonin. And rotating shift work and split shifts mess with our circadian rhythms and are unhealthy on every measure.

Then there’s the obesity crisis. How to fix that? “It has to be 50 things done consistently and well.” The list could include increasing the cost of petrol so people are forced to buy a bike, getting people working closer to home so they can walk to work and removing high-calorie and sugary foods. As we train our children about how to eat well, we need to teach them – and everyone else – the importance of sleep.

Without action, our sleeplessness, and the social, commercial and medical results of it, will only get worse. “We’re writing a disaster in 15-20 years’ time.”

sleep, siesta Photo/Thinkstock

How to have a successful siesta


If you feel sleepy after lunch, that’s entirely normal. We are at our most sleepy from 1-2pm and 1-3am, says Dr Andy Veale.

Some societies, such as the Iberian countries and their former colonies, make use of that. They sleep late having eaten late, but only for about six hours, then grab a nap in the early afternoon, the siesta.

But your power nap should be either less than 30 minutes or longer than 80. This is because we sleep in a regular cycle that lasts 80-90 minutes. We enter through very light sleep, called stage-one sleep, then spend 20-30 minutes in stage-two sleep.

We then go into slow-wave sleep, then have a dreaming period. “If you wake from slow-wave sleep, you feel absolutely dreadful, almost drunk. We call that sleep inertia. That’s why with the power nap it’s absolutely critical to set your alarm after 20-30 minutes after sleep onset so that you’re waking from stage-two sleep and you’ll feel refreshed.”

There are also two periods in the day when it’s almost impossible to go off to sleep, he says: 10-11am and 5-7pm. So it’s important night-shift workers have a good sleep strategy.

They should either go straight to sleep at the end of their shift, or do chores and go to bed at 1pm, then wake up and go to work. The worse thing to do is to go shopping or take the kids to school, then try to sleep.

sleep, head Melatonin (blue) production from the pineal gland (purple) is triggered when darkness falls. Photo/Getty Images

Problems & solutions


Sleep disorders come in many forms. These include apnoea, disorders such as insomnia and circadian rhythm problems and parasomnias such as sleepwalking and talking. The last two disorders are common in childhood but we tend to grow out of them, says sleep expert Dr Andy Veale.

Then there are neurological conditions such as narcolepsy, and REM-associated disorders – which tend to get worse with age and are thought to be related to the degeneration of the brain’s motor centre that keeps us immobile while sleeping – and nocturnal frontal-lobe epilepsies, which are rare and have a genetic component.

Sleep clinics will sometimes employ psychologists to deal with insomnia and offer melatonin and light therapy for people whose sleep patterns are out of whack.

The pineal gland increases levels of melatonin in our blood an hour before sleep onset, but as we get older our levels drop.

Melatonin can ease problems with the timing of sleep, such as delayed sleep phase syndrome, which is often suffered by teenagers who can’t drop off before 2-3am and then sleep until midday, and phase advance syndrome, when we get home from work and feel so tired that we go to bed at 9pm and wake fully alert at 2am.

Often treatments are combined with light exposure or blue-blocker sunglasses in the evening to filter out melatonin-suppressing blue light.

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