Can't sleep at night? Perhaps genetics are to blame.
In a new study, dozens of gene regions linked to insomnia have been pinpointed, and researchers also report a link between insomnia and heart disease.
Gene regions identified
American and British investigators analysed data from more than 450 000 people in the United Kingdom — 29% of whom reported frequent sleeplessness — and identified 57 gene regions associated with insomnia.
Those links were independent of known insomnia risk factors such as lifestyle, caffeine consumption, depression or stress.
"Our findings confirm a role for genetics in insomnia symptoms and expand upon the four previously found [genetic regions] for this condition," said study lead author Jacqueline Lane. She's a researcher at the Center for Genomic Medicine at Massachusetts General Hospital in Boston.
"All of these identified regions help us understand why some people get insomnia, which pathways and systems are affected, and point to possible new therapeutic targets," Lane added in a hospital news release.
The link between insomnia and chronic disease
Researchers also found evidence that increased insomnia symptoms nearly doubled the risk of coronary artery disease. They were also linked to depression and a reduced sense of well-being.
"Insomnia has a really significant impact on millions of people worldwide. We've long known there's a link between insomnia and chronic disease. Now, our findings suggest that depression and heart disease are actually a result of persistent insomnia," said co-lead author Samuel Jones. He's a research fellow at the University of Exeter in England.
New therapeutic targets
Lane said these results open possibilities for future medications. "All of these identified regions are possible new therapeutic targets for insomnia, and 16 of these regions contain known drug targets," she said.
This in turn could have an effect on heart disease, as "the new causal relationships indicate the potential usefulness of insomnia therapeutics as possible treatments for coronary artery disease and depression," Lane said.
The study was published online February 25 in Nature Genetics.
Insomnia affects 10% to 20% of people worldwide, and studies have suggested that about a third of the risk of insomnia is inherited.
Previous research has suggested that insomnia increases the risk of anxiety disorders, alcoholism, major depression and heart disease, but little has been known about the mechanisms involved in that increased risk.
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