Restless Legs Syndrome and Cardiac Risks

It’s previously been shown that people with Restless Legs Syndrome (RLS) have an increase in their blood pressure with each leg movement during sleep; systolic pressure can go up an average of 22 mmHg, and diastolic pressure an average of 11 mmHg. Siimilar changes are seen in people with sleep apnea, who also have an increased likelihood of cardiovascular problems. So it’s not surprising that researchers have sought a possible link between RLS and cardiovascular risk. Harvard scientists reported the findings of their study in the journal Neurology earlier this year, and, bingo! - they found such a link.

This was a cross-sectional observational study. Totals of 1,559 men and 1,874 women living in the community with an average age of 68, who were enrolled in the Sleep Heart Health Study, provided the data. RLS was diagnosed based on responses to 4 questions, occurring at least 5 nights a month and associated with moderate distress. Diagnosis of cardiovascular disease was obtained from the subject’s doctor reports of angina, heart attack, coronary revascularization procedures, stroke, or heart failure.

RLS was diagnosed in 6.8% of the women and 3.3% of the men. After adjustments were made for possible disrupting factors – age, sex, race,body mass index, diabetes, blood pressure, blood lipid abnormalities, and smoking – it was found that cardiovascular disease was twice as common in subjects with RLS as in those without the syndrome. The link was even stronger in those who had RLS symptoms at least 16 times a month, and in those with severe rather than moderate symptoms.

These results, even though obtained with a cross-sectional study – a snapshot in time – strongly suggest that there’s a real association between RLS and the risk of cardiovascular disease. The principal investigator in the study believes this link is due to the increases in blood pressure and heart rate experienced by such patients over a long period of time. Alternatively, the poor quality of sleep in such patients could be influential. Either way, treating RLS would be likely to reduce the increased risk of cardiovascular disease.