A new study has found evidence pointing to a two-way connection between job strain and disturbed sleep, suggesting that interventions to treat sleep problems may also improve work satisfaction.
“The results are important because they show that work demands influence stress negatively, and this link has rarely been investigated in longitudinal studies,” said lead author and principal investigator Torbjörn Akerstedt, a professor in the department of clinical neuroscience at the Karolinska Institute in Stockholm, Sweden.
“Sleep problems are abundant in the industrialized world, and we need to know where mitigation may be most effective.”
The findings show that people with higher work demands exhibited later sleep disturbances at the two-year follow-up. Similarly, those with sleep disturbances later showed a higher perception of stress, higher work demands, a lower degree of control, and less social support at work two years later. However, no link was found between disturbed sleep and physical work environment, shift work schedules, or working hours.
The research team, led by Akerstedt and lead author Johanna Garefelt, analyzed data from the 2008 and 2010 waves of the Swedish Longitudinal Occupational Survey of Health.
The study group included 4,827 participants with a mean age of 48 years, including 2,655 females and 2,171 males. Information regarding sex, age, and socioeconomic position were obtained from national register data.
The researchers used the Karolinska Sleep Questionnaire (KSQ) to identify disturbed sleep, which was defined as having difficulties falling asleep, restless sleep, repeated awakenings, or premature awakening. Work demands, control at work, and social support at work were measured using the Swedish version of the Demand-Control-Support Questionnaire.
The researchers believe that their findings align with prior studies showing that disturbed sleep increases stress response and emotional reactivity. The results imply that promoting better sleep may improve working life by reducing perceived job stress and minimizing negative attitudes toward work.
“The effect of sleep problems on stress emphasizes the importance of good sleep for functioning in everyday life,” said Akerstedt.
According to the American Academy of Sleep Medicine, about 30 percent of adults have symptoms of insomnia, and about 10 percent have severe insomnia that leads to problems in the daytime. This may include fatigue, moodiness, anxiety, memory difficulties, headaches, or upset stomach.
The study results are published in the July issue of the journal Sleep.