Restless Legs Syndrome Linked to Obesity, Fat Waistlines

April 7, 2009— -- A new study suggests that people who have big bellies are more likely to develop restless legs syndrome (RLS), a condition that makes sleep or rest nearly impossible.

An estimated 12 million Americans -- including half a million children -- are affected by the disorder, which causes a "creeping, itching, pulling, creepy-crawly, tugging, or gnawing" sensation in the limbs, according to the Restless Legs Foundation.

"My legs felt like they were being shocked and they would practically move on their own," said Kathy Page of Sedalia, Mo., who suffers from the condition.

"It is hard to explain the immense need to move your legs," she told ABCNews.com. "It's a feeling that if you don't move them and move them now you will just go insane."

"It's a very real condition," said Georgianna Bell, RLS Foundation executive director. "It's something you must have a prescription for -- not just something you pick up over the counter."

Researchers at Harvard University School of Public Health took surveys of 88,000 men and women and found that those who were generally obese -- with a body mass index higher than 30 -- were at 40 percent higher risk of developing restless legs syndrome.

But those with a high waist circumference had an even higher risk -- 60 percent, according to the study that was published in the April issue of "Neurology," the medical journal of the American Academy of Neurology.

Scientists think that the levels of dopamine -- which control both movement and the pleasurable feeling from eating -- may be involved.

Restless legs syndrome affects about 5 percent to 10 percent of the general population, affecting sufferers' work, relationships and health. At its worst, the syndrome can cause anxiety and depression, according to sleep experts.

Often symptoms are worse at night or when resting and resolve upon moving. RLS can also cause difficulties falling or staying asleep. Many also have periodic leg movements -- jerks that occur every 20 or 30 seconds throughout the night.

According to the Harvard study, the higher risks seem to lie in lower levels of dopamine, the chemical in the brain that transmits signals between nerve cells and controls movement.

Though scientists don't exactly know why, lower dopamine levels are associated with Parkinson's disease, as well as restless legs syndrome.