Adding one extra hour of shut-eye to your nightly rest could help improve the health of your arteries, new research suggests.

Scientists from the University of Chicago Medical Center have found that people who sleep less than five hours per night tend to have a higher risk of developing calcified arteries.

Some 27 percent of these study participants developed calcified arteries during the five-year follow-up. In contrast, only 11 percent of subjects who slept for five to seven hours per night developed the condition.

And among people who slept more than seven hours per night? The rate of calcification fell to around 6 percent.

The findings, published in the Journal of the American Medical Association, say that researchers are not clear about the reasons behind the sleep/arterial health connection.

“The consistency and the magnitude of the difference came as a surprise,” commented study director Professor Diane Lauderdale.

“We can only speculate about why those with shorter average sleep duration were more likely to develop calcification of the coronary arteries.”

Some people have found that oral chelation helps them maintain the health of their arteries.