Insomnia may increase adults' risk of asthma, a new study suggests.
High risk factor
People with chronic sleep struggles were three times more likely to develop asthma than those without insomnia, researchers at the Norwegian University of Science and Technology found.
"Insomnia, defined as having difficulties initiating or maintaining sleep, or having poor sleep quality, is common among asthma patients, but whether insomnia patients have a higher risk of developing asthma at a later stage has not been thoroughly investigated," said study co-author Linn Beate Strand.
The study included data from nearly 18,000 people, aged 20 to 65, in Norway. The researchers found that people who said they had difficulty falling asleep "often" or "almost every night" had a 65 percent and 108 percent increased risk, respectively, of developing asthma over 11 years.
People who said they woke too early and couldn't get back to sleep "often" or "almost every night" had a 92 percent and 36 percent increased risk, respectively, of asthma. And those who had poor quality sleep at least once a week had a 94 percent increased risk of developing asthma, the findings showed.
However, the study doesn't prove a cause-and-effect relationship between insomnia and asthma. Further research is required to confirm the findings, Strand said.
About 300 million people worldwide have asthma, a chronic respiratory disorder characterised by wheezing, chest tightness and shortness of breath. Known risk factors include smoking, obesity and air pollution.
Insomnia is manageable
"As insomnia is a manageable condition, an increased focus on the adverse health effects of insomnia could be helpful in the prevention of asthma," Strand said in a news release from the European Lung Foundation.
According to study lead author Ben Brumpton: "A key finding in our study is that those people with chronic insomnia had more than three times the risk of developing asthma, compared to those without chronic insomnia, which suggests that any changes in the body due to insomnia may accumulate and result in more severe harmful effects on the airways."
Brumpton is also affiliated with Norway's Trondheim University Hospital, in the department of thoracic and occupational medicine.
Recent research also suggests that depression and anxiety may be associated with adults' risk of developing asthma, according to background notes with the study.