Repeated muscle twitchings in the legs, a phenomenon known as restless legs syndrome, can damage the heart, possibly by interfering with sleep at night, researchers said Sunday. The condition, they found, is linked to a problem known as left ventricular hypertrophy, in which the wall of the heart becomes thicker, making pumping blood more difficult. Left ventricular hypertrophy, in turn, has been associated with an increased risk of heart attacks and strokes.
An estimated 12 million Americans are thought to suffer from restless legs syndrome, but there is controversy about whether it is a serious problem -- or even a real one. Some recent studies, however, have linked it to specific genes, indicating that it is a physiological phenomenon and not just a minor ailment.
Dr. Arshad Jahangir of the Mayo Clinic in Scottsdale, Ariz., and his colleagues studied 584 patients with a clinical diagnosis of restless legs syndrome who were referred to the Mayo sleep clinic for an overnight sleep study. The team attached an electrical recording device to their legs to monitor the number of times they moved involuntarily during the night and also assessed the patients' heart health, specifically three different measures of left ventricular hypertrophy.
Jahangir told a New Orleans meeting of the American College of Cardiology that the patients were divided into two groups based on the frequency of leg movements: 45% had more than 35 twitches per hour while 55% had fewer than 35. Patients with more than 35 twitches per hour were more likely to have left ventricular hypertrophy and more likely to be older -- by an average of about four years.
In three years of follow-up, the patients with the greatest number of twitches and the thickest heart walls were more than twice as likely to have suffered a heart attack or to have died, Jahangir said.
Jahangir said older people with restless legs syndrome should consult with their physicians to monitor heart health and take steps to minimize other risk factors that might exacerbate the condition.