Restless Legs Syndrome in Heart Failure: A Prevalence Study

Abstract

PURPOSE: Restless leg syndrome (RLS) is a sleep disorder that has been associated with hypertension and cardiovascular disease and shown to reduce quality of life. RLS incidence in the general population is documented at 7-15%, but RLS in heart failure patients has not been studied. METHOD(S): A convenience sample of patients from an urban academic safety net hospital's heart failure clinic was asked to participate from October 2010 through April 2011. Subjects completed the Cambridge-Hopkins Restless Legs Short Form 2 Diagnostic Questionnaire, International RLS severity rating scale, and Short Form 36 Quality of Life Questionnaire (SF-36). Electronic medical records was searched for demographics, body mass index (BMI), ejection fraction, New York Heart Association (NYHA) stage, and RLS risk factors. RESULT(S): Of 102 patients approached, 60 participated in this study. Participants were primarily African American (56%) and equally split among the sexes with mean age 55 years; 55% had renal dysfunction, 41% had iron deficiency anemia, 40% had diabetes, and 13% had neuropathy. Most subjects had systolic heart failure (63%) with NYHA class 2 or 3 (93%). Four subjects had definite RLS; 25 had possible RLS. Subjects with possible and definite RLS were not significantly different in age, race, or known RLS risk factors, NYHA class, heart failure type, BNP, or quality of life measurements compared to those without RLS. These subjects had significantly higher BMI than those without RLS (40.6 vs 33.6, p 0.03). CONCLUSION(S): RLS may affect many heart failure patients. The screening tool for the general population may lack adequate sensitivity to identify RLS in the heart failure population. Common RLS risk factors seem not to predict RLS prevalence, but higher BMI correlates with increased risk for RLS. Heart failure may compromise the same domains of functioning as RLS as assessed by the SF-36, thereby showing little difference between the quality of life of subjects with and without RLS. CLINICAL IMPLICATIONS: Heart failure patients should be screened for RLS.