Module 15

Question 1

What are non-standard shifts and how many Canadians does it apply to?

Answer 1

• Shifts not within 9-5 (+/- 1 hr), Mon-Fri

- 27% of the workforce

Question 2

What are the different shift parameters?

Answer 2

• Pattern
• Speed of shift rotation
• Direction of shift rotation
• Shift length
• Shift changeover times
• Shift recovery time

Question 3

The highest amount of work injuries happen ______

Answer 3

During evening or night

Question 4

What is an odds ratio?

Answer 4

The odds of something occurring at a certain time of day, divided by those odds at any time of day

Question 5

What are the 3 problem areas regarding night shifts?

Answer 5

Productivity, safety, and health impacts

Question 6

Why do night workers experience more accidents?

Answer 6

• Chronic sleep restriction, which impairs cognitive functioning
• Alertness/attention is impaired at night due to circadian rhythms

Question 7

What is the most common complaint of shift workers?

Answer 7

Insufficient sleep

Question 8

Why does sleep onset insomnia occur in shift workers?

Answer 8

Partial adaptation to the previous night shift, turning the worker into a severe night owl

Question 9

Why is it hard for shift workers to get enough sleep?

Answer 9

• The circadian clock promotes waking during the day

- After a few hours of sleep, accumulated sleep need is lessened so it is harder to stay asleep

Question 10

What is a way to increase nap effectiveness during night shifts?

Answer 10

Drink caffeine right before the nap, in order to keep the nap to around an hour and counter sleep inertia effects

Question 11

By how much are shift workers’ chances of developing cardiovascular disease probably increased?

Answer 11

40%

Question 12

Why might the night shift affect GI disease?

Answer 12

Organs used in digestion are controlled by a circadian clock, and shift workers eat when these organs are dormant

Question 13

Lower levels of leptin will _____

Answer 13

Increase body weight

Question 14

Why might shift work be a risk factor for metabolic disease?

Answer 14

• Physiological effects of disrupted sleep
• Disrupted circadian rhythms
• Mistiming of mealtimes

Question 15

How might shiftwork become a carcinogen?

Answer 15

Nocturnal light suppresses melatonin

Question 16

How might clock genes be important for tumour suppression?

Answer 16

By regulating activity of cell cycle genes and tumour suppressor genes

Question 17

Longer shifts are associated with ____ depressive episodes in men and ____ depressive episodes in women

Answer 17

• less

- more

Question 18

What is seasonal affective disorder and how does shift work affect it?

Answer 18

• Depression that begins in the fall and remits in spring/summer
• Lack of light exposure may cause SAD in shift workers

Question 19

What is Shiftwork Sleep Disorder and how do shiftworkers with SSD compare to those without it?

Answer 19

• Sleep onset/maintenance insomnia with severely impaired alertness on night shifts
• Workers with SSD have higher rates of ulcers and depression, and more severe symptoms

Question 20

Why might shift work be a risk factor for substance abuse?

Answer 20

Sleep restriction increases self-administration of addictive drugs

Question 21

How can light be used to phase delay shift workers?

Answer 21

Light pulses prior to body temperature minimum

Question 22

When must melatonin be taken to phase advance a clock?

Answer 22

In the evening

Question 23

What is chronotherapeutics?

Answer 23

The effort to incorporate circadian biology into medicine

Question 24

How can circadian biology affect medicine?

Answer 24

• Diagnosis
• Vulnerability to adverse health effects
• Treatment efficacy
• Treatment side effects
• Pathophysiology

Question 25

What diseases/disorders are shift workers more susceptible to?

Answer 25

• Cardiovascular disease
• Gastrointestinal disease
• Metabolic disorders
• Cancer (including breast cancer)
• Depression
• Substance abuse
• Adverse fertility/pregnancy outcomes
• Worsened social/family life