Prevalence and characteristics of restless legs syndrome in patients with pulmonary hypertension.

Background: Patients with pulmonary hypertension (PH) have an increased prevalence of risk factors for restless legs syndrome (RLS). We performed a cross-sectional study to determine the prevalence and characteristics of RLS in this population.

Methods: Patients filled out two questionnaires during a visit: (1) a diagnostic tool for RLS, based on the core clinical features; and (2) a 10-question rating scale used to assess severity. Data were obtained by medical record review with regard to demographics, characteristics of PH and known RLS risk factors.

Results: Restless legs syndrome was found in 43.6% (24 of 55) (mean age +/- SD: 49 +/- 14 years; 41 women, 14 men) of patients and 54% of these had moderate or severe RLS. Patients with RLS were younger but gender differences were not appreciated. Presence of RLS did not correlate with measures of PH severity; however, patients with RLS were more likely to have a better 6-minute walk distance (p = 0.015) and lower BNP level (p = 0.07) and less likely to be WHO Class IV or require oxygen during the 6-minute walk test. Patients with a history of hypothyroidism (67%; p = 0.04) and those on opioids for relief of leg pain (69%) were more likely to have RLS.

Conclusions: Patients with PH had a very high prevalence of RLS and most had moderate or severe symptoms. RLS was more common in more active patients and those who were hypothyroid or on opioids for relief of leg pain. Patients with PH should be screened for RLS because good treatment options are available.