AbstractIntroductionRestless legs syndrome (RLS) is a common but underdiagnosed neurological syndrome. It is characterized by the feeling of discomfort and desire to move, especially in the lower extremities, which often occurs at night, and the cure or relief of symptoms with movement. Irisin is a hormonelike polypeptide that was first identified in 2012, weighs 22 kDa, consists of 163 amino acids, and is mainly synthesized in muscle. Its synthesis increases with exercise. Here in this study, we planned to investigate the relationship among serum irisin level, physical activity, lipid profile, and RLS.Material and methodsA total of 35 patients with idiopathic RLS and 35 volunteers were included in the study. Then, venous blood was taken from the participants in the morning after 12 h of night fasting.ResultsThe mean value of serum irisin level was 16.9 ± 14.1 ng/mL in the case group and 5.1 ± 5.9 ng/mL in the control group, which was statistically quite significant (p< .001). A significant efficiency (under the curve area 0.886 [0.804–0.967]) of irisin value was observed in the differentiation of patients in the case and control groups.DiscussionSerum irisin level was significantly higher in the case group than in the control group. In conclusion, we suggest that irisin may play a role in the pathophysiology of RLS independently of the intensity and duration of physical activity and anthropometric data, such as body weight, body mass index, and waist/hip ratio.