10/25/2011 06:16 pm ET | Updated Dec 25, 2011

Insomnia Linked With Higher Heart Attack Risk, Study Finds

Experiencing long-term problems with falling asleep can do more than make you chronically exhausted -- a new study shows it could also boost your risk of a heart attack.

The study, published recently in the journal Circulation, shows that people with insomnia have a 27 to 45 percent higher risk of heart attack compared with people who usually sleep well.

Norwegian researchers found that people who had difficulty falling asleep over the last month had a 45 percent increased risk of heart attack, and people who weren't able to stay asleep at night over the last month had a 30 percent increased risk of heart attack.

They also found that people who woke up feeling tired and unrefreshed on a more than weekly basis had a 27 percent increased risk of heart attack.

"We don't know how significant the sleep disturbance must be, or how long it must persist for it to become significant for heart disease," Suzanne Steinbaum, a cardiologist at Lenox Hill Hospital who wasn't involved with the study, told TIME. "But it is safe to say that there is some correlation."

The study was large, involving 50,000 adults who live in Norway. Researchers enrolled the study participants between 1995 and 1996, and then followed up with them 11 years later. By that time, 2,386 of them had had their first heart attack already, WebMD reported.

Researchers also factored in common heart attack risk-raisers like high blood pressure, obesity and old age, but they still found that the link between insomnia and heart attacks existed, according to WebMD.

This isn't the first research to link insomnia with heart attack risk, though TIME reported it is the largest study of its kind to examine the connection.

Insomnia is a common problem, with a price
tag of $63 billion a year because of lost productivity in the United States, according to a recent study. In that study, conducted by Harvard Medical School researchers, 23 percent of the people in the study had insomnia-related problems.

Insomnia can be caused by a whole host of factors. Medications, restless legs syndrome, leg cramps, sleep apnea, depression and anxiety are all things that can get in the way of a good night's sleep, wrote HuffPost blogger Stephanie Silberman, Ph.D., a psychologist and American Academy of Sleep Medicine fellow.