MONDAY, Nov. 2 (HealthDay News) -- Restless legs syndrome, a neurological disorder characterized by a strong urge to move the legs, is much more common among some racial groups than others, a new U.S. study has found.

Researchers interviewed 190 people being seen at a primary care clinic. About 12 percent of those who were black, compared with 36 percent of those who were not black, were found to have restless legs symptoms. Overall, the prevalence of restless legs was 23 percent among the clinic participants.

Among blacks, the prevalence of restless legs syndrome (RLS) was 12 percent for both men and women, compared with 40 percent for women and 29 percent for men among the others, most of whom were white.

"There are significant ethnic differences in the prevalence of restless legs syndrome, but the exact causes of higher prevalence among Caucasians are unknown," study author Dr. Ammar Alkhazna, of the University of Missouri, said in a news release from the American College of Chest Physicians. "This likely reflects a combination of factors, including a genetic predisposition to RLS, diet, including iron intake, medications, and possibly culture."

The study was scheduled to be presented at the annual scientific meeting of the American College of Chest Physicians, held Oct. 31 to Nov. 5 in San Diego.

Symptoms of restless legs also were seen more often in women than men, the study found.

"Some risk factors for restless legs syndrome appear to be more common among women," Alkhazna said. "Women are more likely to be iron-deficient than men and have rheumatoid arthritis, which are known risk factors for RLS."

More information

The U.S. National Institute of Neurological Disorders and Stroke has more about restless legs syndrome.