The association that has been made between restless leg syndrome and heart disease may be mediated, in part, through repeated increases in nighttime blood pressure that occur with periodic leg movements, new research suggests.

Restless leg syndrome or RLS is a movement disorder that causes uncomfortable sensations in the legs that worsen when a person is inactive, such as during sleep.

The “repetitive rise in blood pressure during periodic leg movements could be harmful to the cardiovascular system, especially in severe cases of RLS, the elderly, and those with a long history of the disease,” senior investigator Dr. Paola Lanfranchi, from the Universite de Montreal in Quebec, Canada, said in a statement.

“Past studies have shown that significant blood pressure changes, as shown in our study, are associated with the development of vascular and heart damage,” Lanfranchi continued. “Furthermore, drastic blood pressure surges at night have been associated with a higher rate of stroke in the elderly.”

In their study, reported in the April 10th issue of Neurology, Lanfranchi’s team performed overnight sleep studies (polysomnography) and beat-to-beat blood pressure monitoring on 10 people with RLS.

With each periodic episode of leg movement during sleep, blood pressure rose appreciably.

Elderly patients and those with long-standing RLS were found to have the most pronounced changes in blood pressure with nighttime leg movements.

Further studies are needed to determine whether the nighttime blood pressures seen with repetitive leg movement actually translate into a heightened risk of cardiovascular disease, the researchers conclude.

SOURCE: Neurology April 10, 2007.