Nearly a third of Korean shift workers face sleep disorder risks: research

By KTimes

Roughly three out of 10 shift workers in Korea are at risk of sleep disorders, with older adults and women being particularly vulnerable, according to researchers at the Sleep Center at Kyung Hee University Hospital in Gangdong, Seoul, on Monday.

Neurology professors Shin Won-chul and Byun Jung-ick surveyed 624 shift workers and found that 32.2 percent, or 201 people, were in the at-risk group for sleep disorders. The body’s circadian rhythm can adjust by only about one hour per day, making it difficult for workers to adapt to abrupt changes in their schedules.

The study found that older participants and women were more likely to score higher for insomnia, daytime sleepiness and depression. Those with shift cycles that changed within one month were also at greater risk. Korea currently has around 3 million shift workers.

With the World Health Organization classifying night shift work as a group 2A carcinogen, experts say proper sleep management is essential.

Although irregular routines are unavoidable due to the nature of shift work, researchers say organizing work schedules from morning to afternoon to night shifts can help the body adapt more smoothly. Maintaining the same shift for one to two weeks is also more beneficial than changing shifts daily.

Improving work and sleep environments is also important. Bright lighting during night shifts can help the body perceive nighttime as daytime, reducing drowsiness. After working overnight, using blackout curtains during daytime sleep allows for deeper rest. It is also recommended to avoid lying down immediately after meals and to wait at least three to four hours before sleeping. Aiming for seven to eight hours of sleep daily is essential.

Stress remains a key factor disrupting sleep for Koreans. According to a global sleep health survey by international sleep solutions firm ResMed, stress was the top reason cited for poor sleep by Korean respondents, at 67 percent, 10 percentage points higher than the global average of 57 percent. Anxiety followed as the second-most reported sleep disruptor at 49 percent.

The number of days per week when Koreans reported high-quality sleep was also lower than the global average — 3.82 days for men and 3.38 days for women, compared to the global averages of 4.13 and 3.83 days, respectively. Additionally, more than half of Korean office workers — 53 percent — said they had taken sick leave due to sleep deprivation.

The survey covered 30,026 people across 13 countries, including 1,500 respondents from Korea.

This article from the Hankook Ilbo, the sister publication of The Korea Times, is translated by a generative AI system and edited by The Korea Times.