Inverse: A study links daytime sleepiness to telomere length and lays the groundwork for taking EDS seriously.

“We typically think of sleepiness as a symptom of something, whether that’s narcolepsy or like sleep apnea, or just, you know, staying up too late doing whatever it is you were doing,” Bock says. “But now we’re looking at it through the lens of its own cardiovascular risk factor.”

The new research also draws a line between daytime sleepiness and sleep apnea, which is linked to the opposite effect on telomeres: lengthening. Telomere lengthening is often associated with biological “youth” and healthfulness, while the shortening observed in this study is associated with aging and cell damage. But it’s not so straightforward. In fact, longer-than-average telomeres can be linked to more serious diseases.