Race is strong predictor for restless legs syndrome

November 2, 2009

New research shows that Caucasian women may suffer from restless legs syndrome (RLS), a sleep disorder characterized by the strong urge to move the legs, up to four times more than African-American women. The study, presented at CHEST 2009, the 75th annual international scientific assembly of the American College of Chest Physicians (ACCP), found that, overall, non-African-American (NAA) patients experienced RLS four times more often than African-Americans (AA). Furthermore, 2 out of 5 Caucasian women were found to have RLS, nearly four times the incidence of RLS in African-American women and the highest incidence among all groups.

"There are significant ethnic differences in the prevalence of restless legs syndrome, but the exact causes of higher prevalence among Caucasians are unknown," said Ammar Alkhazna, MD, University of Missouri, Kansas City, MO. "This likely reflects a combination of factors, including a genetic predisposition to RLS, diet—including iron intake—medications, and possibly culture."

To determine the incidence of RLS among AA and NAA patients, Dr. Alkhanza and his colleagues analyzed standardized interview responses from 190 patients seen at a primary clinic. Of the patients, 103 were AA (42 percent were men) and 87 were NAA, of which 40 percent were men and the majority were Caucasians. Among AA, the diagnosis of RLS was definite in 12 percent of patients, while among NAA, the diagnosis of RLS was definite in 36 percent. In the AA group, the prevalence of RLS was 12 percent for both genders. In the NAA group, the prevalence of RLS among men was 29 percent and 40 percent among women.

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

Researchers also found that the overall prevalence of definite RLS was 23 percent, which is significantly more than many previous studies have reported at 3 to 10 percent. Dr. Alkhanza explains that this increased prevalence of RLS could be attributed to the specific study population.

"We believe our study results reflect at least our clinic's patient population. Because our patient population is multiracial and quite diverse, we expect our results would be similar in other large, urban centers with similar pools of patients," said Dr. Alkhanza. "However, as many diseases and medications can lead to the development of restless legs syndrome, there will likely be a difference between populations attending medical clinics as opposed to those who are well and healthy."

"Restless legs syndrome is a common sleep disorder that may not be easily recognized by patients and clinicians," said Kalpalatha Guntupalli, MD, FCCP, President of the American College of Chest Physicians. "Educating clinicians and patients about the signs and symptoms of RLS may raise awareness about this overlooked condition and lead to earlier diagnosis and treatment."

Source: American College of Chest Physicians