Say Good Night to Heart Disease with at Least Six Hours of Sleep

According to findings from University of Chicago Medical Center researchers, skipping out on adequate rest sets us up for heart disease. Adding just one hour of sleep to your nightly routine has the same positive effect as lowering systolic blood pressure by 17mm/Hg.

Study director Diane Lauderdale, PhD, associate professor of health studies at the University of Chicago Medical Center, finds the results puzzling. Twenty-seven percent of those who slept less than five hours per night had calcified arteries during a five-year follow-up. Only eleven percent of the 495 participants who slept five to seven hours nightly had signs of coronary artery disease. The number dropped to six percent for those who slept more than seven hours, and the greatest impact was on women.

According to Dr. Lauderdale, "The consistency and the magnitude of the difference came as a surprise. It's also something of a mystery. We can only speculate about why those with shorter average sleep duration were more likely to develop calcification of the coronary arteries."

Shorter sleep duration has recently been linked to several health problems, including weight gain, high blood pressure and diabetes. Scientists have not been able to pinpoint the exact reasons. Now we see that a good night’s sleep may also reduce our risk of heart disease.

An ongoing project, begun in 1985 was used for the research, called the Coronary Artery Risk Development in Young Adults (CARDIA) study. The study was initiated to find out what combination of events leads to heart disease.

The participants underwent cardiac CT scoring that measures calcium buildup in the arteries that leads to heart disease. CT scans were performed five years apart. The volunteers also underwent sleep studies, answered questionnaires about sleep, and kept logs of how many hours they were in bed, focusing on sleep duration.

The researchers were not able to reach any definite conclusions about how sleep duration is associated with heart disease, but they believe several factors may be involved. They believe that the stress hormone cortisol may play a role, though measurements were not taken in all of the volunteers. Another possibility involves longer periods of lower blood pressure, which naturally occur when we sleep.

Dr. Lauderdale says that though the study was small, and should be performed again…”there is enough here to make a point. Although there are constant temptations to sleep less, there is a growing body of evidence that short sleep may have subtle health consequences. Although this single study does not prove that short sleep leads to coronary artery disease, it is safe to recommend at least six hours of sleep a night."

If you suffer from insomnia, or interrupted sleep patterns, consider taking action. The study shows us that sleeping less than six hours a night may be a set-up for future heart disease.

Kathleen Blanchard, RN

Skipping sleep may signal problems for coronary arteries