If you’re sleeping fewer than five hours or more than nine hours, you could be putting yourself at an increased risk for heart disease, according to a study conducted by researchers at the West Virginia University School of Medicine.

"This was the first time the relationship between sleep and heart disease had been investigated in such a large study with representations from all major racial-ethnic groups in the United States."

Dr. Anoop Shankar

The study, conducted by Anoop Shankar, M.D., Ph.D., associate professor in the Department of Community Medicine, examined more than 30,000 adults who participated in the 2005 National Health Interview Survey. Dr. Shankar and his colleagues found both short and long sleep durations to be independently associated with heart disease. The results were adjusted for age, sex, race-ethnicity, smoking, alcohol intake, body mass index, physical activity, diabetes, high blood pressure and depression.

“We showed that both short and long sleep durations are related to cardiovascular disease separately in all major racial-ethnic subgroups in the United States,” Dr. Shankar said. “It was a huge study, and therefore the statistical power was never an issue. This was the first time the relationship between sleep and heart disease had been investigated in such a large study with representations from all major racial-ethnic groups in the United States.”

Shankar said that those who sleep less than five hours are twice as likely to develop heart disease. On the opposite end of the spectrum, those who sleep nine hours or more a day are one-and-a-half times more likely to develop heart disease than those who sleep seven hours a day.

Though the study showed a correlation between sleep and heart disease, a cause for the increased risk was not found.

“We hope these findings encourage primary care physicians to evaluate the sleep patterns of patients as a risk factor for heart disease and would like to see public health initiatives focused on improving sleep to reduce the burden of heart disease,” Shankar said.

The study was published in the August issue of “SLEEP,” the official publication of the Associated Professional Sleep Societies, LLC, a joint venture of the American Academy of Sleep Medicine and the Sleep Research Society.

-WVU-

CONTACT:Angela Jones, HSC News Service
304-293-7087; jonesan@wvuh.com