The relationship between Willis-Ekbom disease and serum ferritin levels among children in Northwestern Turkey

OBJECTIVE To examine the incidence of restless legs syndrome (RLS) among children with iron deficiency, or iron deficiency anemia, or both, and the relationship between RLS prevalence and serum ferritin levels. METHODS This prospective, cross-sectional, case controlled study was carried out between January and June 2013, and included 98 iron deficiency and/or iron deficiency anemia, and 102 healthy children referred to the Neurology and Pediatric Departments of the Medical Faculty of Bezmialem Vakif University, Istanbul, Turkey. Both groups were evaluated according to the International Restless Legs Syndrome Study Group diagnostic criteria. RESULTS The range of ferritin levels was 0.01-12 mg/ml in patients while it was 12.3-91.8 mg/mL in the control group. Restless legs syndrome was detected in 61.2% of children with iron deficiency anemia, and in 37.3% of children with normal biochemistry values. A statistically significant correlation was found between serum ferritin levels and frequency of RLS. In patients with serum ferritin levels higher than 50 ng/ml, 92.3% had no RLS, while 55.2% of patients with serum ferritin levels lower than 50 ng/ml had RLS. The patients with serum ferritin levels of > 50 ng/ml had a significantly higher incidence of RLS. Serum ferritin levels were significantly different between the 2 groups. CONCLUSION The incidence of RLS, also known as Willis-Ekbom Disease, is high in children aged between 8-18 years with iron deficiency, or iron deficiency anemia, or both. This finding supports the importance of iron replacement therapy especially during the growth and development of children.