If you snore, have trouble falling asleep or tend to wake up unrefreshed, your chances of having metabolic syndrome are higher than if you usually get a good night's rest, according to a new study. Metabolic syndrome is a group of risk factors for heart disease, stroke and diabetes, defined as having at least three of the following: too much abdominal fat, high triglycerides, low HDL (good) cholesterol, high blood pressure and high blood sugar.

Adults who snore loudly and frequently were twice as likely to develop metabolic syndrome over a three-year period as adults who don't snore, the study said.

Compared to non-snorers, loud snorers "had a more than two-fold increased risk of developing high blood sugar (hyperglycemia), and were 92 percent more likely to have low levels of 'good' cholesterol," said study researcher Wendy Troxel, assistant professor of psychiatry and psychology at the University of Pittsburgh.

Researchers examined the sleep habits of 812 adults, ages 45 to 74, who did not have metabolic syndrome at the start of the study. After three years, 14 percent of the adults had developed metabolic syndrome.

Adults who had trouble falling asleep had an 80 percent higher risk of developing metabolic syndrome than adults who slept normally. And adults who had unrefreshing sleep had a 70 percent higher risk of metabolic syndrome than adults who slept normally, according to the study.

However, after the researchers examined the effects of each type of sleep disturbance independently, they found that only loud snoring and difficulty falling asleep predicted the development of metabolic syndrome, the researchers said.

Snoring is caused by breathing in air through a partially blocked airway, according to the American Academy of Sleep Medicine. Air that vibrates as it flows past the tissues in the back of the throat, produces the snoring sound.

About 24 percent of women and 40 percent of men are habitual snorers, and it's more common in people who are overweight because they have more fat in the back of the throat that vibrates, according to the American Academy of Sleep Medicine.

Previous studies have shown that sleep disturbances can affect hormones that regulate weight, brain activity and inflammation, and are linked with metabolism and heart health, Troxel told MyHealthNewsDaily.

Sleep disturbances also lead to sleepiness and fatigue, which can lead a person to become physically inactive, she said, which can in turn bring on metabolic syndrome. Some evidence also suggests that snoring-related vibrations can impact the risk of heart problems by damaging the walls of the carotid artery, which passes through the neck, and by triggering inflammation that's associated with atherosclerosis.

The finding should prompt health-care providers to ask their patients about sleep problems during check-ups as a screen for metabolic syndrome, Troxel said.

Next, Troxel said she hopes to examine the degree to which sleep symptoms are associated with heart disease. She is also currently studying the links between psychosocial risk factors and sleep disturbances.

The study was published today (Dec. 1) in the journal Sleep.

Follow MyHealthNewsDaily staff writer Amanda Chan on Twitter @AmandaLChan.

This article was provided by MyHealthNewsDaily, a sister site to LiveScience.