“Sleep Was Easier to Give Up Than the Job”

Several people I interviewed for The Savvy Insomniac blamed their insomnia on stress at work. A trial lawyer attributed his nighttime wake-ups to “mostly job related stress.” A 52-year-old woman on Social Security disability saw her insomnia as resulting from 14 years of shift work as a dispatcher with emergency services.

Work can interfere with sleep in many ways, including shortening sleep duration. The CDC has just released a report on the categories of work most likely to shorten people’s sleep. Here’s what they are and how they may relate to chronic insomnia.

Persistent trouble sleeping can develop from years of shift workSeveral people I interviewed for The Savvy Insomniac blamed their insomnia on stress at work. A trial lawyer attributed his nighttime wake-ups to “mostly job related stress.” A 52-year-old woman on Social Security disability saw her insomnia as resulting from 14 years of shift work as a dispatcher with emergency services.

Work can interfere with sleep in many ways, including shortening sleep duration. The CDC has just released a report on the categories of work most likely to shorten people’s sleep. Here’s what they are and how they may relate to chronic insomnia.

Occupations Associated With Short Sleep

The findings are based on surveys conducted on working adults in 2013 and 2014. By telephone, workers answered questions about the kind of work they did and how much sleep they normally got in 24-hour period. In all, the CDC analyzed the responses of nearly 180,000 people. The data show a high percentage of workers in these five broad categories typically slept less than 7 hours a night:

  1. Production (printing workers, plant and system operators, supervisors, and production workers), about 43%
  2. Healthcare Support (nursing, psychiatric, and home health aides), about 40%
  3. Healthcare Practitioners and Technical (health technologists and technicians, health diagnosing and treating practitioners), about 40%
  4. Food Preparation and Food-Related (supervisors, food preparation and serving workers, cooks), about 40%
  5. Protective Service (fire fighting and prevention workers, law enforcement officers), about 39%

Occupations Involving Shift Work

The jobs in all five categories often involve shift work. Round-the-clock operations in hospitals, factories, restaurants, and police and fire departments make it necessary for some employees to work at times when we’re normally at rest. In other work situations employees regularly rotate from one shift to the next.

Shift work is known to interfere with sleep, contributing to shortened sleep and excessive sleepiness. It disrupts circadian rhythms and has a negative effect on health, contributing to a rise in certain cancers, obesity, and impaired glucose tolerance. It also increases the risk of injury.

Could Shift Work or Work-Related Short Sleep Lead to Chronic Insomnia?

Lynda, the retired dispatcher on disability, felt there was a direct link between her insomnia and her work in emergency services. Day jobs she’d held previously gave her “no trouble sleeping at night.” But the dispatch job was different:

I really do believe that the shift work was a major contribution to my sleeping problems. I base this on comparisons with my coworkers. I don’t know any policeman, fireman, or dispatcher who didn’t have trouble sleeping while swinging shifts on a regular basis. I loved this line of work because it was always rewarding to be able to help someone, or be responsible for saving someone’s life. Sometimes, depending on the size of the catastrophe, it could be very intense. You could feel the adrenaline pumping. . . . It just gave you a great feeling knowing that YOU were the one who made a difference. I guess that would explain why I couldn’t sleep after coming off of working something major. Sleep was easier to give up than the job.

How It Could Happen

The neurocognitive model of insomnia suggests how chronic insomnia might develop from work-related stress and short sleep. In fact any stressful situation can trigger acute (or temporary) insomnia, including stress at work. But acute insomnia does not necessarily become chronic. Sleep can—and, in many people, does—return to normal once the situational triggers for insomnia get resolved.

But in the five categories of jobs identified by the CDC, less-than-perfect conditions of employment may be a given when you accept the job. Want to work in emergency services? Fine. You’ll work rotating shifts.

If you find this situation stressful because it interferes with your sleep, you may be tempted to resort to measures that often make sleep worse—using alcohol to get to sleep, for example, or spending long stretches lying awake in bed.

Lying awake in bed often leads to worry and rumination, and to high-frequency brain activity during sleep onset and beyond. Eventually you wind up conditioning arousal in your body and brain. Et voilà, you’re saddled with chronic insomnia—all because you were a good citizen and willing to work around the clock.

I never had an easy time working split shifts and I avoided other jobs that might disrupt my sleep. People like Lynda are more adaptable. But . . . at what cost?

If you’ve had a job that shortened or otherwise interfered with your sleep, how did you manage the situation, and were their any long-term effects?

What Makes You Vulnerable to Insomnia?

The causes of insomnia are still unknown, but many factors can make people more and less vulnerable to it.

A prospective study of Norwegian nurses offers new evidence of several factors, some well known and others that have gotten less attention in the past.

vulnerability to insomnia depends on several thingsWhen I set out to write my book about insomnia, I asked dozens of insomniacs what they thought had caused their insomnia. Several mentioned constitutional factors.

There are certainly grounds for thinking that a genetic component is involved. People who have a first-degree relative with insomnia are 7 times as likely to suffer insomnia as people without insomnia in the immediate family.

Other people I interviewed attributed their insomnia to stress at work or to family problems. Still others blamed their insomnia on an inability to quiet their mind at night.

The causes of insomnia are still unknown, but many factors can make people more and less vulnerable to it. A prospective study of Norwegian nurses offers new evidence of several factors, some well known and others that have gotten less attention in the past.

Anxiety and Depression

There’s plenty of evidence pointing to a relationship between insomnia and mood disorders. In the nurses’ study, where investigators reviewed data on 799 nurses collected at 2 time points 2 years apart, nurses higher on anxiety and depression measures in 2009 were significantly more likely to report insomnia symptoms in 2011.

The reverse relationship also held for insomnia and anxiety: nurses reporting insomnia in 2009 were more likely to have developed anxiety 2 years later. Surprisingly, although insomnia is widely understood to be a causal factor in depression, the nurses’ study found no evidence of this.

Morningness and Eveningness

The nurses in this study were all shift workers. Other research has suggested that people who dislike getting up early in the morning have an easier time adapting to shift work, where work at night is required.

In the current study, though, the nurses who disliked getting up early in the morning were actually more inclined to develop insomnia than the early risers. Other research has shown that people who like to get up early tend to have better lifestyle regularity and more regular sleep habits. Both these things tend to protect people from developing insomnia.

Personality Traits

Some people function quite well despite sleep loss while others feel drowsy and lethargic. (This is largely determined by genetic factors and is thus a stable trait.) Languidity—the tendency to experience drowsiness and lethargy after losing sleep—was found in the nurses’ study to predict an increase in insomnia symptoms over the 2-year period. No surprises here. Impairments in daytime functioning are classic symptoms of insomnia.

Another personality trait—flexibility, or the ability to sleep or stay awake at odd hours—has generally been known to protect against the development of insomnia. Among shift workers, this would be an especially useful trait. But in this study, a high score on flexibility had no positive or negative relationship with insomnia.

Smoking, Drinking, and Caffeine

The overall harmful effects of tobacco, alcohol, and caffeine on sleep are now well known. For many years insomnia was attributed to people drinking too much scotch or too much coffee.

More recently, studies have shown that people with insomnia do not typically drink more alcohol or caffeinated drinks than people who sleep well, and the nurses’ study supports this finding. None of these lifestyle factors predicted an increase in insomnia over time. In fact, nurses reporting insomnia symptoms in 2009 actually reported drinking less caffeine in 2011.

Bullying at Work

Several work-related stressors are known to increase the risk of poor quality sleep, and bullying—persistent exposure to negative actions from others—is one. Day-to-day contact with tyrannical bosses and manipulative supervisors often leads to psychological distress.

Nurses subjected to bullying at work reported more insomnia symptoms over time than the nurses working under better conditions. No surprises here: the worry and stress that result from bullying are two of the leading causes of sleep problems among workers.

Spillover Between Work and Family

Stress in one domain can affect another. In the nurses’ study, negative spillover from work to family and from family to work predicted an increase in insomnia symptoms over time. Conversely, insomnia led to reports of more work-to-family conflicts over time.

Shift Work

Finally, shift work, involving night work and rotating shifts, is known to precipitate insomnia. But in this group of nurses, the association did not hold. This unexpected result might be due to the young age of the nurses (average age 33) and their overall good health compared with shift-working nurses overall, many of whom likely self-selected out of the study.

What factors do you think led to your insomnia?

Shift Work and Sleep: Always Incompatible?

The worst insomnia I ever had came when I was living in Mexico. I worked a split shift then, teaching English classes from 7 to 10 in the morning and then from 7 to 9 at night. This schedule might not sound difficult: a few hours’ work at both ends of the day, with the rest of the day free for sightseeing, napping, or doing whatever I pleased.

It was tough for me.

Insomnia and a poorer quality of life may result from working irregular hoursThe worst insomnia I ever had came when I was living in Mexico. I worked a split shift then, teaching English classes from 7 to 10 in the morning and then from 7 to 9 at night. This schedule might not sound difficult: a few hours’ work at both ends of the day, with the rest of the day free for sightseeing, napping, or doing whatever I pleased.

It was tough for me.

I’m a morning person, so getting up at 5:30 or 6 is normal. But gearing up for the evening classes took effort. Then I was wired after class. I had to spend at least a few hours winding down, and by then it was after midnight. The thought of having to throw my clothes on again at 6 made me anxious: what if I couldn’t sleep?

Working this split shift was a set-up for insomnia. I tossed and turned in bed, and on too many days I woke up to the sound of the alarm clock feeling achy and spent. It was all I could do to show up for my early class on time.

Shift Work and Chronotype

I put up with this schedule for one semester, but for millions of Americans, shift work is an ongoing part of life. Whether it’s a job in a hospital or in IT, in manufacturing or in the transportation industry, it probably involves working nights, evenings, or early mornings; or on rotating shifts or shifts other than the standard 8 to 5.

Shift work may keep you solvent, but it can also have negative effects on sleep and health. It disrupts the functioning of the body clock, altering physiologic processes and the activity of genes.

A new study in Current Biology suggests that adjusting work time to correspond more closely with an employee’s natural cycle of activity and rest may alleviate some of the harms associated with shift work. To conduct their research, investigators took a group of factory workers and divided them by chronotype—their preferred hours of sleep and activity:

  • Early birds (who preferred to go to bed and get up early)
  • Intermediate types
  • Night owls (who preferred to go to bed and get up late)

Then, to promote better sleep and reduce the mismatch between preferred wake and work times, they exempted the early birds from working their most challenging shift: the night shift (10 p.m. to 6 a.m.). Likewise, the night owls were exempted from working their most challenging shift: the morning shift (6 a.m. to 2 p.m.). The intermediate group served as control subjects, continuing to work morning, evening, and night shifts.

More Sleep and Satisfaction

The results confirmed many of the researchers’ predictions. Exempted from working their most challenging shifts,

  • Both early birds and night owls slept up to 30 minutes longer on workdays.
  • Both early birds and owls reported better sleep quality and a greater sense of well-being on workdays.
  • Early birds’ and owls’ sleep time on weekends more closely matched their sleep time on workdays (a consistent sleep schedule on weekends helps keep the body’s circadian system in sync).
  • Early birds reported increased satisfaction with their leisure time.

The researchers conclude by stating what many shift workers must already suspect: working more in accordance with natural circadian preferences might improve shift workers’ sleep, quality of life, health, and even productivity.

Whether many industries would or could take chronotype into account when making work assignments is an open question. My solution to the shift work problem in Mexico was to take a job with more regular hours.

If you’ve had experience working irregular hours, how has it affected your sleep and quality of life?

 

Artificial Lighting Harmful to Sleep and Health

We hear a lot about the effects of light on sleep. Light in the evening—especially the blue light emitted by devices with screens—blocks secretion of the hormone melatonin, causing symptoms of insomnia. Low lighting during the day also delays melatonin onset and shortens the night.

Shift work, in which workers are routinely are exposed to light at night and must sleep during daylight hours, is so likely to disturb people’s sleep that the problem has its own name: Shift Work Sleep Disorder.

Not only do unnatural lighting conditions interfere with sleep. More and more evidence suggests that artificial lighting is behind the uptick in modern diseases such as cancer.

Insomnia and cancer are more likely in brightly-lit, urban areasWe hear a lot about the effects of light on sleep. Light in the evening—especially light emitted by devices with screens—blocks secretion of the hormone melatonin, causing symptoms of insomnia. Low lighting during the day also delays melatonin onset and shortens the night. Shift work, where workers are routinely are exposed to light at night and must sleep during daylight hours, is so likely to disturb people’s sleep that the problem has its own name: Shift Work Sleep Disorder.

Not only do unnatural lighting conditions interfere with sleep, say epidemiologists Richard G. Stevens and Yong Zhu. More and more evidence suggests that artificial lighting is behind the uptick in modern diseases, the topic of their recent opinion piece in Philosophical Transactions of the Royal Society of London B.

“It’s a new analysis and synthesis of what we know up to now on the effect of lighting on our health,” said Stevens in a University of Connecticut press release. “We don’t know for certain, but there’s growing evidence that the long-term implications of this have ties to breast cancer, obesity, diabetes, and depression, and possibly other cancers.”

In the Beginning

Humans evolved in an environment where the sun was the sole light source influencing internal circadian rhythms. The rising and setting of the sun determined when they slept and ate; it also set the rhythm for fluctuations in body temperature, gene expression, and hormone production. Sunlight in the daytime and darkness at night kept these systems cycling on a 24-hour day.

But the artificial lighting we spend our time in now is dim and poorly timed. Too little light during the day and too much at night lead to the disruption of circadian rhythms, insomnia, and increased susceptibility to disease.

Artificial Lighting and Cancer

Research suggests there is a relationship between exposure to light at night and breast cancer. Several studies show that women who work at night are more susceptible than women who work during the day. Night work is associated with melatonin suppression and, in women, higher levels of circulating estradiol, a reproductive hormone linked to breast cancer. Changes in the lymphatic system have also been observed.

Population studies, too, suggest a connection between breast cancer and exposure to light at night. Researchers in two studies used ambient light as measured by satellite at night to compare breast cancer risk across communities. They found a correlation between ambient light levels and breast cancer. “This has been tested and confirmed within Israel,” Stevens and Zhu write, “and among 164 countries of the world.”

Studies in molecular epidemiology also point to a relationship between circadian disruption and breast cancer. Long-term exposure to shift work alters patterns of gene expression throughout the body in ways that may increase breast cancer risk. Shift work may be a causal factor in colon and prostate cancers as well.

Do What You Can to Protect Your Health

You may be able to reduce your risk of developing these and other light-related health problems:

  • Get a healthy dose of sunlight during the day. If you can’t, buy a light box and use it.
  • Cut down on screen time at night. If you have a choice between an e-reader and a book, go for the book. Incandescent light is better than the blue light emitted by screens.
  • Use heavy curtains to block out all light sources when you’re sleeping.
  • Use red light if you must have light at night. (See my suggestion for red nightlights.) Firelight is circadian friendly for the same reason: it contains an abundance of red wavelengths.
  • Cut down on red meat to reduce the risk of colon cancer. Epidemiological studies show there is a correlation between eating red meat, which is high in iron, and developing the disease.

Sleep Well Despite Poor Work Conditions

Stressors at work— demanding bosses, looming deadlines, performance reviews, and the like—can fuel insomnia. But low light and the timing of work can also affect sleep. Lack of exposure to sunlight on the job and night or shift work may reduce total sleep time and deprive you of energy in your waking hours.

But you may be able to manage these less-than-optimal work conditions in ways that improve both your sleep and your stamina.

working without natural light has a negative effect on sleep and staminaStressors at work— demanding bosses, looming deadlines, performance reviews, and the like—can fuel insomnia. But low light and the timing of work can also affect sleep. Lack of exposure to sunlight on the job and night or shift work may reduce total sleep time and deprive you of energy in your waking hours.

But you may be able to manage these less-than-optimal work conditions in ways that improve both your sleep and your stamina.

Working without Natural Light

Working without the benefit of sunlight during the daytime has a surprisingly negative effect on sleep, a new study in the Journal of Clinical Sleep Medicine shows. The goal of the study was to compare the vitality and sleep of employees that worked in windowless cubicles to those of subjects whose workstations were exposed to natural light.

Not only did the 22 workers in the windowless cubicles report less activity during the daytime and poorer quality sleep. On average, they also got 46 minutes less sleep than the 27 employees who worked near windows.

Out of Sync

The timing of your workday can also interfere with your sleep. Nearly 15 million full-time American workers labor on schedules that involve night, rotating or irregular shifts, which necessitates the resetting of the body clock.

Having to work when you’d normally be asleep and to sleep when you’d normally be awake causes changes in the activity of genes, a study recently published in the journal Proceedings of the National Academy of Sciences shows. Genes control the production of proteins, and to function optimally, protein production needs to coordinate with the natural cycle of activity and rest.

When the body clock is reset, as occurs in people who do night and shift work, the number of genes synched up to the body’s natural circadian rhythms falls rather dramatically, pushing digestive and other physiologic processes out of whack. Ten percent of shift workers are regularly diagnosed with “Shift Work Sleep Disorder”—they feel sleepy on the job and have insomnia when it’s time to sleep.

Night owls may choose to work the night shift and, given their delayed circadian rhythms, this schedule suits them to a “T.” Others fare poorly. The years when I worked a split shift were the years when my insomnia was at its worst.

What’s a Worker to Do?

If low light is a problem at work,

  • Invest in a light box and use it (for tips on how to use a light box, see my blog on winter insomnia)
  • Go outside or to sunlit parts of the building during breaks.
  • If you do work near windows, keep the blinds open and, if necessary, use anti-glare shades for computer screens.

If the timing of your workday is a problem,

  • Aim for consistency in your sleep schedule. It may be tempting to alter your sleep schedule on weekends to maximize time with family and friends. But having to readjust to your weekday schedule on Monday may leave you struggling to stay alert at work and tossing and turning in bed.
  • Manipulate your exposure to light. Bright light in the work environment will help to keep you alert and on your toes. But exposure to sunlight on your way home from work will tend to delay sleep further. If your goal is to get to sleep immediately after work, wear dark glasses on the way home.
  • Make judicious use of caffeine. Drinking coffee at the beginning of your shift should not interfere with getting to sleep when you get home. But the caffeine-sensitive will want to avoid caffeine later in the work shift. If sleepiness becomes a problem, the better strategy is to get up and move around.