Trouble falling asleep, frequent night wakings and chronic insomnia could double or even triple the risk of developing asthma, a new European study has found.

Asthma is a chronic lung disease that currently affects 300 million people worldwide. Many risk factors, such as smoking, obesity, atmospheric pollution and depression and anxiety symptoms, have been associated with a risk of developing the disease in adulthood.

While many asthma patients experience sleep-related problems, the reverse phenomenon -- whether insomnia patients have a higher chance of developing asthma -- has not been studied in depth.

A team of researchers set about investigating the link between insomnia -- defined as "having difficulties initiating or maintaining sleep, or having poor-quality sleep" -- the risk of developing asthma in adulthood.

The scientists used data from a Norwegian study called HUNT (Nord- Trondelag Health Study) to assess the risk of asthma in 17,926 participants aged between 20 and 65. Participants reported sleep problems (difficulty falling asleep, night wakings, poor-quality sleep) as well as any asthma symptoms at the beginning and end of the study.

The results, published in The European Respiratory Journal, found that participants who reported difficulty falling asleep "often" or "almost every night" over the course of the previous month had a 65 per cent and 108 per cent increased risk of developing asthma in the next 11 years.

Those who reported night wakings with trouble getting back to sleep "often" or "almost every night" had a 92 per cent and 36 per cent increased risk of developing the disease. For patients reporting poor-quality sleep more than once a week, the risk of developing asthma increased by 94 per cent.

The researchers then looked at patients with chronic insomnia who reported at least one insomnia symptom at the start of the study and 10 years later. For these participants, the risk of developing asthma tripled compared to those without chronic insomnia.

For the study's authors, insomnia may cause changes in the body which could accumulate over time and risk causing more serious, harmful effects on the airways.

"As insomnia is a manageable condition, an increased focus on the adverse health effects of insomnia could be helpful in the prevention of asthma," concludes Dr Linn-Beate Strand, one of the study's co-authors.