Two key events, the beginning of daylight saving time (DST) and World Sleep Day, are drawing global attention to sleep and its effects on health. Globally, 1 in 3 adults do not achieve enough sleep or quality sleep. As much as 45% of adults have chronic insomnia.

Canadians are not immune to these problems. About 41% of Canadians do not get the recommended 7-8 hours of sleep per night, according to national survey data.

“There’s a societal trend where a lot of people of all ages don’t get the recommended amount of sleep; they’re not prioritizing sleep enough to make room for it in their lives,” Rébecca Robillard, PhD, director of clinical sleep research at the University of Ottawa Institute of Mental Health Research and co-chair of the Canadian Sleep Research Consortium in Ottawa, told Medscape News Canada.

Though DST and World Sleep Day only occur once a year, the effects of poor quality and inadequate sleep are cumulative. Yet few clinicians routinely inquire about sleep during routine checkups.

Out of Alignment

Sleep experts say that the biannual time shift disrupts the body’s natural circadian rhythm, which regulates the sleep-wake cycle. Most are in favor of discarding DST, which was first adopted by Ottawa in 1908 to conserve energy during World War I. It was standardized across Canada in the late 1960s.

“People tend to focus on the ‘lose-the-hour’ thing, but that’s not what the evidence shows,” Colleen Carney, PhD, director of the Sleep and Depression Laboratory at Toronto Metropolitan University, Toronto, told Medscape News Canada. “DST creates an unnatural shift in how our internal clocks connect with the environment and the environmental cues via the eye,” she said. “Most people are able to adjust around it and make up for lost sleep not with more sleep, but, importantly, with greater sleep depth and quality.”

Switching to DST is analogous to traveling across time zones. “When you change time zones, you feel jet-lag-like symptoms: mental cloudiness, fatigue, things like that. It’s because we’ve artificially shifted cues in the environment to mismatch our body,” she said.

But DST is distinctive in one important way. “When you land in your destination, the sun has risen at the appropriate time for that location. I refer to the sun because it is the most potent type of synchronizer in the external world and with the biological clock,” said Robillard. “When we change the time in relation to DST, we maintain the misalignment with the light from the sun and create issues,” she said.

The loss of morning light coupled with longer light times during the evening hours suppresses sleep hormones and pushes bedtime later. But social and work demands mean that people are waking at the same time as they did before the switch.

Dangerous Impairments

“The mismatch between the internal clock and the natural cycle of the sun creates a lot of health issues; the biological clock is involved in almost every biological function across the body, eg, heart rate, cardiovascular regulation, metabolism, the immune system, hormone release, and temperature regulation,” said Robillard. She also pointed to a third disruptive misalignment: our social clocks.

Research has shown that abrupt changes in light/dark exposure (eg, in shift workers) go well beyond affecting circadian clock genes and hormones like melatonin and cortisol. They also result in a state of internal desynchronization (a biological resistance to adaptation) and a struggle to stay awake.

Clinton Marquardt, one of Canada’s leading sleep and fatigue specialists, advises the nation’s transportation and safety industry giants on sleep-related fatigue in shift workers. He refers to these workers as elite occupational athletes “who are asking their brains and bodies to perform at very high levels in biologically and socially challenging conditions and situations.”

One of the greatest concerns about the biannual clock changes, which many people adjust to in a few days, is their association with fatigue-related impairments in judgment, Marquardt told Medscape News Canada. These impairments can result in injury, damaged equipment, and, at worst, fatalities.

Marquardt illustrated this concern by describing a Safety Board investigation of a Medevac helicopter crash. The pilot had just returned from a busy family vacation in another time zone and immediately gone back to work.

“The pilot returned home, crossed a few time zones, and probably had a sleep debt. He started work, did a few flights, and on his final flight, he had a conversation with 2 medical professionals (no patients) on board,” said Marquardt.

A short time later, “the flight data recorder showed a dramatic slant to one side, a roll to the side, nose down so much that the helicopter became uncontrollable and crashed to the ground,” he said.

The investigation revealed that a conversation between the pilot and his medical crew, the pilot said that he “felt good enough to get home, at least.” A bit later, one of the crew said he could use some sleep, to which the pilot agreed. The crash resulted in a preventable fatality, said Marquardt.

Canadian insurance agencies have documented an increase in traffic accidents of as much as 21% in the days immediately following the change to DST. As many as 1 in 5 Canadians have also said that they feel unsafe during driving because of the time changes.

Marquardt is equally concerned about the negative outcomes associated with sleep and circadian rhythm disruptions that are not as closely monitored as traffic accidents and fatalities. “There’s a great paper that shows that sleep problems are linked to 13% of occupational injuries,” he said.

Talk to Your Patients

Carney and Robillard are careful to distinguish between sleep debt (i.e., the daily buildup of sleepiness); conditions that prevent the opportunity to produce deep, restorative sleep (like obstructive sleep apnea); and chronic insomnia. The latter is marked by a circadian mismatch with the external environment, a chronic jet-lag-like loop in which people are consistently fatigued, and behavioral conditioning that associates bedtime with wakefulness and worry.

The spring and fall clock transitions provide opportunities for doctors and other health professionals to query patients about their sleep quality, depth, and related issues.

“Sleep is such a foundation of health that I often struggle to understand how it’s not a payoff for patients to ask about it and address it,” said Robillard. “We’ve been working on a 3-minute assessment and other open-access resources to help guide clinicians who don’t have a background in sleep to quickly detect when something’s wrong and then orient them to the right places.

“Asking about sleep hygiene just doesn’t cut it. And 40%-50% of people who come through my lab walk out with a diagnosis of unsuspected sleep apnea. We have to move toward better screening methods, but in the meantime, asking your patients about how they feel about their sleep and how it impacts the quality of their days is a core component of healthcare,” said Robillard.

Carney and Robillard reported having no relevant financial relationships. Marquardt reported providing training and consulting services primarily to clients in the transportation industry and being paid directly for his services.

Liz Scherer is an independent health and medical journalist who frequently reports on Canadian and EU Health News.