Genes suggest poor sleep may drive inflammation more than the other way around

Insomnia and the inflammation marker CRP share 125 genetic regions, and insomnia more likely leads to higher CRP than the reverse, in a genetic study of UK Biobank data published Oct. 14, 2026, in Sleep. Better sleep may help calm inflammation.

People who sleep badly often have higher levels of C-reactive protein (CRP), a blood marker of inflammation. But does poor sleep cause inflammation, does inflammation disturb sleep, or do both share a common cause?

What did the study look at?

Using UK Biobank data, the researchers confirmed that CRP was higher in 130 611 people with insomnia than in 327 375 people without it. Then they used several genetic methods to look for shared DNA regions and to test the direction of the link, including Mendelian randomization, which uses genes as a kind of natural experiment.

What did the study find about sleep?

• Insomnia and CRP were genetically correlated: genes that raise the risk of one tend to raise the other.
• 125 DNA regions were linked to both.
• These regions pointed to biological processes such as how DNA is packaged, immune signaling, cellular aging and programmed cell death.
• Six regions likely share the same causal variant, including near the genes APOE and HLA-B.
• The genetic analysis gave stronger evidence for a direction from insomnia to higher CRP than from CRP to insomnia.

Why does this matter?

Chronic inflammation is linked to heart disease, diabetes and other conditions of aging. If poor sleep pushes inflammation up, then treating insomnia could be one way to reduce that burden, not just to feel more rested.

How solid is this evidence?

It’s moderate. Mongevity rates it C on our A-to-E scale. Genetic methods like Mendelian randomization can hint at cause and effect, but they rely on assumptions, and the data come mostly from people of European ancestry in one biobank. It doesn’t show that treating insomnia lowers inflammation.

What does this mean for you?

If you have insomnia that lasts weeks or months, treat it as a health issue, not just an annoyance. Cognitive behavioral therapy for insomnia is the first-line treatment and works for many people. Ask your doctor about it before relying on sleeping pills.

How do I explain this at dinner?

Scientists looked at the genes of hundreds of thousands of people and found that sleeping badly and having more inflammation share many of the same genes. The clues suggest bad sleep may stoke inflammation. A good question for the table: what helps you fall asleep on a busy night?

In one sentence: genes suggest insomnia and inflammation are linked, with stronger evidence that poor sleep raises inflammation than the reverse.