Large-scale study links abnormal sleep length to heart risk condition

When it comes to sleep, getting too much of a good thing may be a sign there's something wrong. Researchers in the U.K. have tied long sleep to metabolic syndrome, a condition that increases the risk of heart disease, diabetes and stroke.

The latest study to tie excessive sleep to adverse health effects was presented as a poster this morning at SLEEP 2010.

The large-scale study involved more than 29,000 people in Guangzhou, China aged 50 or older.

The findings indicated people who reported regularly sleeping more than eight hours were 15 percent more likely to have metabolic syndrome. The results were adjusted for potential confounding factors, like demography and lifestyle.

After making the same adjustments, links between short sleeper and metabolic syndrome disappeared.

The National Heart, Lung, and Blood Institute reports metabolic syndrome is a group of obesity-related risk factors that includes excess abdominal fat, high triglycerides, low HDL cholesterol, high blood pressure and high blood sugar. A person diagnosed with metabolic syndrome has at least three out of those five factors.