DENVER — Restless legs syndrome was associated with a significantly increased prevalence of cardiovascular disease in the Wisconsin Sleep Cohort Study, John W. Winkelman, M.D., reported at the annual meeting of the Associated Professional Sleep Societies.
This is the first report of such a relationship. Dr. Winkelman termed the connection “intriguing” and worthy of further investigation.
Possible explanations for the restless legs syndrome (RLS)/cardiovascular disease association include adverse cardiovascular effects due to the repeated autonomic arousals that accompany the abnormal leg movements. Alternatively, it could be that cardiovascular disease in some undefined way promotes RLS. Or perhaps the two share a common genetic predisposition, speculated Dr. Winkelman of Brigham and Women's Hospital in Boston.
He reported on 2,770 participants aged 40–75 years in the Wisconsin Sleep Cohort Study. The prevalence of RLS among this representative sample of Wisconsinites was 10.6% as defined by at-least-weekly occurrence of all three of the following complaints: a repeated urge to move the legs, disrupted sleep due to strange and uncomfortable feelings in the legs, and improvement upon getting up and walking.
The prevalence of RLS didn't differ significantly by gender. It did, however, increase with age, as has been reported in other studies.
The prevalence of cardiovascular disease was 4.6% among individuals without RLS, 7.4% in those experiencing RLS roughly once per week, and 11.9% among those who experienced RLS on a nightly basis.
In a multiple logistic regression analysis adjusted for potential confounders including age, body mass index, smoking, diabetes, and treatment for obstructive sleep apnea, individuals with RLS on a weekly basis had a 1.37-fold greater rate of known cardiovascular disease than did those without RLS, while those with RLS nightly had a 2.19-fold increased rate.
In addition to being the first study to link RLS and cardiovascular disease, this is also the first to report that RLS is associated with both self-reported poor general health and excessive daytime sleepiness. Moreover, the severity of these two health problems was correlated with the frequency of RLS. Individuals with RLS once per week were 2.14-fold more likely than were those without RLS to characterize their general health as only fair or poor; those with nightly RLS were 3.31-fold more likely to do so, in an adjusted analysis.
Similarly, individuals with weekly RLS were more likely to report excessive daytime sleepiness and had higher Epworth Sleepiness Scale scores than did participants without RLS. Adults with nightly RLS reported more daytime sleepiness and had higher Epworth scores than did those with less frequent RLS.