Sleep Deprivation

Singaporeans are amongst the most sleep deprived nation worldwide.

In fact, Singapore is the 3rd most sleep-deprived of the 43 cities profiled in a report published recently. Only in Tokyo and Seoul the people sleep lesser. Not sleeping enough and not sleeping well is not okay. Chronic sleep deprivation, whatever the reason, will significantly affect your health, work performance, safety, and general sense of well-being.

There are many causes of sleep deprivation. Most link Singaporeans’ lack of sleep to the well-established culture of working long hours. The stresses of daily life may intrude upon our ability to sleep well or perhaps, we trade sleep for more work or play. In our increasingly connected world, there are activities round the clock and with constant distraction from the Internet, it should come as no surprise that a typical working adult or teenager will not clocked the obligatory 7 hours of sleep. The situation tends to aggravate towards year-end when festive drinking and events makes for even lesser sleep. Lifestyle-related behaviour is the major cause of insufficient sleep in the majority of Singaporeans.

However, it is critically important to realise that sleep deprivation can be due underlying medical conditions; the most common being chronic insomnia and obstructive sleep apnea.

For those with a medical reason for their sleep deprivation, they would need to see a sleep specialist for further evaluation.

What is the consequence of inadequate sleep?

1. Sleepiness Can Lead to Accidents

Sleep deprivation was a factor in some of the biggest disasters in recent history: the 1979 nuclear accident at Three Mile Island, the massive Exxon Valdez oil spill, the 1986 nuclear meltdown at Chernobyl, and others.

Sleep loss is also a big public safety hazard every day on the road. Drowsiness can slow reaction time as much as driving drunk. The National Highway Traffic Safety Administration estimates that fatigue is a cause in 100,000 automobile crashes and 1,550 crash-related deaths a year in the U.S. The problem is greatest among people under 25 years old. We do not have the numbers in Singapore.

Studies show that sleep loss and poor quality sleep also lead to accidents and injuries on the job. In one study, workers who complained about excessive daytime sleepiness had significantly more work accidents, in particular, repeated work accidents.

2. Sleepiness Can Slow You Down

Sleep plays a critical role in thinking and learning. Lack of sleep hurts these cognitive processes in many ways. First, it impairs attention, alertness, concentration, reasoning, and problem solving. This makes it more difficult to learn efficiently.

Second, during the night, various sleep cycles play a role in “consolidating” memories in the mind. If you do not get enough sleep, you will not be able to remember what you learned and experienced during the day. It is easy to understand why sleep deprivation can adversely affect work performance and school performance.

3. Sleep Deprivation Can Lead to Serious Health Problems

Sleep disorders and chronic sleep loss can put you at risk for:

  • Heart disease
  • Heart attack
  • Heart failure
  • Irregular heartbeat
  • Hypertension
  • Stroke and
  • Diabetes

According to some estimates, 90% of people with insomnia – a sleep disorder characterized by trouble falling and staying asleep – also have another health condition.

4. Lack of Sleep Can Impair Sex Drive

Sleep specialists say that sleep-deprived men and women report lower libidos and less interest in sex. Depleted energy, sleepiness, and increased tension may be largely to blame.

For men with sleep apnea, a respiratory problem that interrupts sleep, there may be another factor in the sexual slump. A study published in the Journal of Clinical Endocrinology & Metabolism in 2002 suggests that many men with sleep apnea also have low testosterone levels. In the study, nearly half of the men who suffered from severe sleep apnea also secreted abnormally low levels of testosterone during the night.

5. Sleepiness Can Lead to Clinical Depression

Over time, lack of sleep and sleep disorders can contribute to symptoms of depression. People diagnosed with depression or anxiety were more likely to sleep less than six hours at night. Once they have adequate sleeping hours, their anxiety or depression improved.

One of the most common sleep disorders amongst seniors is chronic insomnia and it has the strongest link to depression. In a 2007 study of 10,000 people, those with insomnia were five times more likely to develop depression than those without. Insomnia is often the initial presentation of depression. Insomnia and depression feed on each other; sleep loss often aggravates the symptoms of depression, and depression can make it more difficult to fall asleep.

6. Lack of Sleep Ages Your Skin

Most people have experienced sallow skin and puffy eyes after a few nights of missed sleep. It turns out that chronic sleep loss can lead to lacklustre skin, fine lines, and dark circles under the eyes.

When you do not get enough sleep, your body releases more of the stress hormone cortisol. In excess amounts, cortisol can break down collagen deposit in the skin thus making the skin aged.

Sleep loss also causes the body to under-produce the human growth hormone. The human growth hormone has an important role in promoting growth hormones. It also plays a part in increasing muscle mass, thickening the skin, and strengthening bones. It is usually released during deep sleep i.e. slow wave sleep. It is our body’s natural way of repairing and renewing our body.

7. Sleepiness Makes You Lose Focus and Decreases Attention Span

If you want to keep your memory sharp and good, you really ought to get plenty of sleep.

In 2009, researchers determined that a specific type of brain wave called ‘sharp wave ripples’ is responsible for consolidating memory as well as transferring short term memory (hippocampus) to long term memory (neocortex of the brain). This process is critical for us to learn a skill or knowledge. Sharp wave ripples occur mostly during the deepest levels of sleep.

8. Sleep Deprivation Can Lead to Weight Gain

When it comes to body weight, consistent research has shown that the lack of sleep is related to an increase in hunger and appetite, and possibly to obesity. According to a 2004 study, people who sleep less than six hours a day were almost 30 percent more likely to become obese than those who slept seven to nine hours.

Recent research has focused on the link between sleep and the hormones that regulate appetite. Ghrelin stimulates hunger and leptin signals satiety to the brain and suppresses appetite. These two hormones are being researched intensively currently. Decreased sleep time is associated with decreases in leptin and elevations in ghrelin.

Not only does sleep loss appear to stimulate appetite. It also stimulates cravings for high-fat, high-carbohydrate foods. Ongoing studies are considering whether adequate sleep should be a standard part of weight loss programmes.

9. Lack of Sleep May Increase Risk of Death

In the “Whitehall II Study,” British researchers looked at how sleep patterns affected the mortality of more than 10,000 British civil servants over two decades. The results, published in 2007, showed that those who had cut their sleep from seven to five hours or fewer a night nearly doubled their risk of death from all causes. In particular, lack of sleep doubled the risk of death from cardiovascular disease.

10. Lack of Sleep Can Affect Our Judgement, Discrimination and Conceptualisation Ability

This will negatively impact our work performance and school performance. The lack of sleep affects our ability to assess situations accurately and act on them wisely.

Sleep-deprived people seem to be especially prone to poor judgment when it comes to assessing what lack of sleep is doing to them. The danger is that we may not even be aware that our judgement and cognitive function have been impacted. In our increasingly fast-paced world, functioning on less sleep has become a kind of badge of honour. But sleep specialists say if you think you are doing fine on less sleep, you are probably wrong. And if you work in a profession where it’s important to be able to judge your level of functioning, this can be a big problem.

Studies show that over time, people who are getting six hours of sleep, instead of seven or eight, begin to feel that they have adapted to that sleep deprivation – they have gotten used to it. But if you look at how they actually do on tests of mental alertness and performance, they continue to go downhill.

So there comes a point in sleep deprivation when we lose touch with how impaired we are.

 

Dr Chong Yaw Khian is a Consultant with the Department of Otorhinolaryngology at Tan Tock Seng Hospital (TTSH). He currently runs the Snoring and Sleep Apnoea Clinic at TTSH and his main clinical interests are in otology and sleep disorders.