Trouble sleeping, especially trouble falling asleep, may be associated with high blood pressure, according to a new study from China. This is the first study to show that certain people with insomnia are at risk for high blood pressure.

Compared to normal sleepers who fell asleep quickly, people with insomnia who took more than 14 minutes to fall asleep during the day were three times as likely to have high blood pressure readings or a doctor’s diagnosis of hypertension, the authors report in the journal Hypertension.

Insomnia with increased alertness during the day, or hyperarousal, is associated with increased chronic secretion of stress hormones like cortisol, which may lead to hypertension, researchers wrote.