Health experts have identified two areas that employers can focus on to tackle the widespread problem of worker insomnia and its impact on safety standards.

These are work-related fatigue and chronic musculoskeletal pain.

The researchers, from the Norwegian University of Science and Technology and other institutions, say that workers who are constantly worn out from work are more than twice as likely to experience insomnia symptoms than those who are never or seldom fatigued, and the relationship between fatigue and insomnia is amplified by chronic musculoskeletal pain.

According to the researchers, eight per cent of the working population suffer from insomnia, while one-third experience insomnia symptoms, like having troubled sleep and feeling sleepy during the day.

Insomnia and sleep problems are associated with an increased risk of: adverse health outcomes in workers, like diabetes and cardiovascular disease; sickness absences; impaired productivity; and poor safety outcomes, they say.

In a study of more than 16,000 workers, surveyed between 1995 and 1997, and again from 2006 to 2008, the researchers found work-related physical fatigue was strongly associated with an increased risk of insomnia in working women and men, especially those who also suffer from chronic musculoskeletal pain.

“Our results suggest that chronic musculoskeletal pain amplifies the adverse association between work-related physical fatigue and risk of insomnia,” they say.

They say it’s possible that chronic pain exacerbates work-related physical fatigue, which in turn increases the risk of insomnia symptoms, but “the exact mechanisms and temporal association between fatigue and chronic pain are poorly understood”.

Previous studies have shown that physical work demands like repetitive movements, twisting, vibrations and heavy lifting were associated with disturbed sleep, but a recent prospective study found no links between long-term exposure to physically demanding work and the risk of insomnia symptoms.

The current study found physical work demands (as opposed to work-related fatigue) were not associated with the risk of insomnia symptoms in women, and men with heavy physical work had a lower risk of insomnia.

“It is conceivable that long-term exposure to similar physical work demands may elicit different effects depending on the physical capacity of the individual worker,” the researchers say.

“Perceived work-related physical fatigue may therefore capture the relative load imposed by physical work exposure better than classifications based on work type and physical work demands.”

They say this finding suggests that “physical fatigue induces sleep problems irrespective of work demands”.

“The underlying mechanisms for such an effect are unclear, but lack of proper rest and recovery could be a stressor that in turn has a negative influence on sleep.

“These findings suggest that there is an interplay between work-related physical fatigue and musculoskeletal pain that should receive particular attention in the prevention of insomnia in working populations.”

Physical work exposure, chronic musculoskeletal pain and risk of insomnia: longitudinal data from the HUNT study, Norway. Eivind Schjelderup Skarpsno, et al, Norway, Occupational and Environmental Medicine, online first April 2018, doi: 10.1136/oemed-2018-105050.

Source: OHS Alert, 26 April 2018