Increased frequency of the restless legs syndrome in adults with cystic fibrosis.

Background: Patients with cystic fibrosis (CF) may suffer from iron deficiency which is a known risk factor for the restless legs syndrome (RLS), however, its prevalence has not yet been investigated in these subjects.

Patients And Methods: Adult out-patients with CF (n = 39) and healthy volunteers (n = 32) were recruited for this study. A diagnosis of RLS was made based on the diagnostic criteria established by the International Restless Legs Syndrome Study Group (IRLSSG). The IRLSSG rating scale was used to assess the severity of the disease. Furthermore, in the CF group, parameters of iron metabolism were measured in peripheral venous blood samples.

Results: The RLS occurred more frequently in the CF patients than the controls (n = 13/33,3% vs. n = 2/6,3%; p < 0,05). In the CF patients suffering from RLS, the mean score of the IRLSSG rating scale was 17,2 ± 9,4 indicating moderate disease severity. Iron deficiency was present in the majority of the CF patients investigated (n = 33/84,6%), however, serum iron, ferritin and transferrin levels as well as transferrin saturation were similar in those with vs. without RLS.

Conclusions: The frequency of the RLS is increased in adult patients with CF. On an average, its severity is moderate and it is not related to iron deficiency as evaluated by serum parameters of iron metabolism.