Researchers are reporting that disrupted nightly sleep may increase the risk of atherosclerosis, or hardening of the arteries, through a unique pathway that involves chronic inflammation throughout the bloodstream. The study adds to growing evidence that poor sleep is a key risk factor for cardiovascular disease and suggests that improving sleep may help reduce this risk, the researchers say.

Past studies have shown that sleep disruption is associated with an increased risk of atherosclerosis, which is linked to heart attack and stroke, but the mechanism has been unclear. For the new study, the researchers analyzed the effect of sleep quality on heart health among more than 1,600 middle-aged and older adults from the Multi-Ethnic Study of Atherosclerosis. They found that poor sleep led to an increase in neutrophils, a type of white blood cell linked to inflammation, which in turn led to an increase in atherosclerosis. The study, funded by NHLBI, appeared in PLOS Biology.