First published in the NASGP Newsletter 10th October 2022
How? There is a whole industry built on poor sleep, but the key to understanding it lies in the circadian rhythms which govern all of life.
As a junior doctor, I trudged through post-take ward rounds, longing to climb into bed alongside any of the patients, even the most scabrous and sick, just for a moment’s rest.
After a week off I would cope with the first night on-call, feeling “this isn’t too bad”. The next night my grip was weakening, by the third I was beyond remembering what normal life was like.
GPs know that when you’re exhausted it’s hard to be empathetic with an anxious patient – or your spouse – or to be patient with the fumbles of a more junior colleague. Bone-weary people don’t think straight. Bill Clinton admitted he made most of his mistakes when he was too tired. Me too. And the third mate of the Exxon Valdez oil super-tanker.
In the doctors’ mess, exhaustion was a badge of honour. For Margaret Thatcher and Ronald Regan, sleep was for wimps. On Wall Street, money never slept.
Exhaustion is expensive – it costs the UK economy around £40 billion a year – so understanding more about sleep is economically important. We now know that the shorter your sleep, the shorter your life. We know that jet lag increases the risk of heart disease, and that every year when the clocks go forward there are more heart attacks. (It’s called social jet lag.) Tired people catch more colds, have more depression, more cancer, more diabetes, and more of them end up with dementia. Fatal Familial Insomnia, a prion disease, kills in months.
We have some clues about how it works. Even a week of lost sleep changes the DNA of genes associated with the inflammation which underlies so many chronic health problems. Toxins aren’t eliminated if you don’t sleep. Beta amyloid accumulates in the brain of people suffering chronic wakefulness. Every stage of sleep has its role in repairing body and brain, so poor sleep disrupts vital processes. If you are tired, you won’t remember the facts you are mugging up for tomorrow’s exam, you won’t come up with E=mc2 or the answer to that crossword clue.
Ducks sleep with half a brain at a time, but human brains need complete rest. Whether you are a hunter-gatherer or a master of the universe, the sweet spot is seven to eight hours’ sleep. The hours need not be continuous, but the siesta must be long enough to include a period of deep sleep and the social clock must geared to it – as, traditionally, in Spain.
Orthosomnia, obsession with sleep, is a pot of gold for manufacturers and the purveyors of dreams. Try special pyjamas, £6000 mattresses, attend Guardian masterclasses, take advice from Gwyneth Paltrow, Tik Tok and the Lancet.
Simpler measures are probably more helpful: exercise, a regular lifestyle and not letting the sun go down on your anger. Apps may be useful, though they can give rise to app anxiety. (The Sleepio app was reviewed in the last NASGP newsletter.) A dark and cool bedroom helps, too. Contrary to much advice, the light from your iPad is apparently too low to disturb sleep patterns; it’s checking social media and reading messages from lawyers which keep you awake.
The influence of circadian rhythms on illnesses and treatments is barely mentioned in medical curriculums.
But the bedrock of 21st century sleeplessness is that modern life doesn’t take account of our biological clocks.
Circadian rhythms govern all aspects of our lives. Hardly surprising since the pacemakers in all our cells are no different from those in single-celled organisms. Most people’s natural rhythm is slightly longer than 24 hours, and the pacemakers in different tissues aren’t exactly in phase, but those third cells in the retina which detect light feed the information to the rest of the brain, so we barely notice daily small readjustments. Though if you live north of the Arctic Circle you need rigorous social timetables so you don’t drift into free-running cycles.
It used to be thought that people who always work nights will adapt. They don’t. However hard shift workers try to reverse day and night, their biological clocks and social clocks are always out of synch with the sun clock. The price is poor health, high divorce rates and premature death.
During puberty circadian rhythms are delayed, explaining why adolescents are practically nocturnal. Some schools now defer the start of lessons, with benefit to pupils’ health and academic performance. The physical and mental health of elderly people and those with dementia could be improved if we took account of how age and brain failure disrupt circadian rhythms.
What does this mean for GPs? Shift work may have suited some (not me) but health professionals are having to fill so many shifts that the hours are as long and as debilitating as they ever were.
It seems that no-one in the NHS is adding up the cost of exhaustion. Underfunded, dangerously short-staffed, there is no easy way to establish a rota with sufficient rest between shifts. Even providing suitable foods at times which fit in with the circadian rhythm of digestion is beyond most hospitals.
A nap is a useful short-term pick-me-up. Google employees can retire to nap pods. I recall the bliss of five minutes lying down while the theatre was being prepared for a 4am crash caesarean. And providing taxis to take exhausted doctors home would save lives.
Some operations may be more effective if performed at a particular time of day. Probably many medications would be better taken at times determined by the circadian rhythm of the target tissues. But how many people could keep to a complicated pill regime?
Circadian rhythm disturbances undermine both sleep and nutrition. Yet these fundamentals to health are ignored when jobs and timetables are designed. The influence of circadian rhythms on illnesses and treatments is barely mentioned in medical curriculums. Health services are very slow to catch up with simple changes and taking body clocks into account would require a fundamental redesign. But with the NHS at breaking point, it feels like an opportunity we can’t afford to miss.