Results of a recent study show that African-Americans experience a lower occurrence of periodic limb movements during sleep (PLMS) than do Caucasians.

The population-based sampling from tri-county Detroit found the overall prevalence of PLMS to be 7.6%. African-Americans in the study had a lower prevalence of only 4.3%, while 9.3% of Caucasians experience PLMS.

In the study, PLMS was defined as an average of 15 or more leg movements per hour of sleep. It was found that individuals with PLMS were slightly older than those who did not have PLMS.

“The study is consistent with the idea that genetic factors may play a role in the development of PLMS,” says principal investigator Christopher L. Drake, PhD, of Henry Ford Hospital in Detroit.

The study included 592 individuals between 18 and 65 years of age, who underwent an overnight polysomnogram and a five-nap, daytime multiple sleep latency test.

Results of the study were published in the journal Sleep.