Middle-aged woman with Restless Legs Syndrome (RLS), may have a higher risk of developing high blood pressure, according to new research reported in Hypertension: Journal of the American Heart Association.

RLS is a common yet under-recognized sensory motor disorder characterized by intense, unpleasant leg sensations, and an irresistible urge to move the legs. RLS symptoms can lead to poor sleep and daytime drowsiness. It affects as many as 15 percent of the adult population.

Researchers found that women who reported:

• Five to 14 incidences of RLS each month had a 26 percent prevalence of high blood pressure.
• More than 15 incidences of RLS had a 33 percent prevalence of high blood pressure.
• No RLS symptoms had a 21.4 percent prevalence of high blood pressure.

"If future prospective research confirms this association, then early diagnosis and treatment of RLS might help prevent hypertension," said Salma Batool-Anwar, M.D., M.P.H., the study's first author, and a researcher in the Sleep Medicine Division at Brigham and Women's Hospital and an instructor in medicine at Harvard Medical School in Boston, Mass. "In some cases the treatment of RLS is as simple as prescribing iron supplements, therefore, women who have symptoms suggestive of RLS should talk to their physicians."

In 2005, researchers asked 97,642 women participating in the Nurses Health Study II about their RLS symptoms and hypertension status. More than 80 percent of the participants responded. The average age was 50.4 years.

Specifically, they asked about unusual crawling sensations, or pain combined with motor restlessness and an urge to move. The questions were based on the international restless legs study group criteria.

Researchers found there was a significant relationship between RLS severity and blood pressure, and greater frequency of RLS symptoms was associated with higher concurrent systolic and diastolic blood pressures. This association was independent of other potential covariates such as age, body mass index, smoking status, and presence of stroke or myocardial infarction.

Previous studies in men have suggested a link between frequency of RLS symptoms and the prevalence of high blood pressure.

Co-authors are Atul Malhotra, M.D.; John Forman, M.D.; John Winkelman, M.D., Ph.D.; Yanping Li, Ph.D.; and Xiang Gao, M.D., Ph.D. Author disclosures are on the manuscript.

The National Institutes of Health funded the study.