With the cells blocking vital pathways, this can lead to a higher risk of strokes and dangerous heart conditions, researchers found. The scientists hope their findings will bolster public awareness into the dangers of poor sleep. Renowned expert Professor Matthew Walker led the research team. The author of the international bestseller Why We Sleep and an academic at University of California, said: “Improving sleep may offer a novel way to reduce inflammation and thus reduce the risk.
“These findings may help inform public health guidelines that seek to increase the continuity of sleep as a way to improve health and decrease the burden of heart disease on society.”
Poor sleeping habits have long been linked to unhealthy hearts, but scientists have not fully grasped why until now.
To measure sleep disruption, Prof Walker’s researchers used both lab-based polysomnography, which records brain waves, blood oxygen levels and heart rate during sleep, and a simple movement detector worn on the wrist over multiple nights.
The researchers used standard blood cell counts to measure levels of white blood cells responsible for blocking pathways.
Two white cells in particular, called neutrophils and monocytes, gather in the arteries of those with patchy sleep, it was said.
The team discovered that fragmented sleep, as measured by the wrist detector, predicted higher levels of coronary artery calcium, a measure of inflamed arteries.
They concluded a poor night’s rest led to damaged arteries and worsened inflammation.
Even after accounting for known contributors to artery disease, including age, sex and body mass index, sleep disruption was still found to aggravate inflammation.
Professor Walker added: “These results provide a mechanism to explain the long-standing observation that poor sleep increases the risk of heart disease and stroke, and suggests simple and direct ways to reduce such risk.”
No association was found with participants who reported their own poor sleep when prompted.
This finding suggests that asking patients about their sleep may not be a useful tool for assessing their sleep-related risk of heart disease.
The study by Prof Walker and his team was published in the PLOS Biology journal.