Restless Leg Syndrome and Association with Serum NT Pro-CNP.

INTRODUCTION: Restless leg syndrome (RLS) pathophysiology is yet unclear. The role of iron deficiency, dysfunction of the dopaminergic system, and hypoxia are well-known mechanisms related to pathophysiology. C-type natriuretic peptide (CNP) is a neuropeptide that is released from the cerebral structures and endothelium. In current literature, serum concentrations of NT pro-CNP were correlated to concentrations of the central nervous system. In this study, we aimed to investigate the relationship between serum NT pro-CNP and other biochemical markers with RLS. MATERIALS AND METHODS: A total of 45 patients with idiopathic RLS and 45 healthy subjects were included in the study and the levels of iron, ferritin, and NT pro-CNP were measured. In addition, the correlation of iron, ferritin levels, sleep disorders, and the severity of RLS with NT pro-CNP was evaluated. RESULTS: Serum iron level was lower in patients with RLS compared with healthy controls, but there was no significant difference between groups regarding ferritin levels. NT pro-CNP level was significantly lower in patients with RLS compared with the healthy controls. The sensitivity and specificity of NT pro-CNP were 80% and 88.9%, respectively, in the diagnosis of RLS. DISCUSSION: Our findings may support the hypoxic and dopaminergic mechanisms. It has been also reported that the CNP receptor is widely expressed in cerebral structures and the spinal cord, this also plays an important role in the development of dorsal sensorial neurons of the spinal cord. In other words, low NT pro-CNP might be related to symptoms of RLS. CONCLUSION: Serum levels of NT pro-CNP are relatively decreased in patients with RLS. A pharmacological agent, which can increase CNP, might be an effective treatment choice for symptoms of RLS and CNP might be used as an assessment tool in evaluating the efficacy of treatment.