Abstract
Introduction
Restless legs syndrome (RLS) is a common sensory motor neurological disorder that is related to iron-dopamine dysregulation and immune system alteration. Hepcidin is the key regulatory hormone of systemic iron homeostasis and is related to inflammatory processes. We aimed to evaluate the clinical utility of hepcidin as a diagnostic biomarker and index of therapeutic responses in RLS patients after dopaminergic treatment.
Methods
Non-anemic and drug-naive RLS patients (n=18) and healthy controls (n=15) were enrolled. Hepcidin (pre-prohepcidin) and iron-related values in serum were measured upon the first visit in both groups and 12 weeks later after dopaminergic treatment in 12 RLS patients. Information about sociodemographic characteristics, sleep-related profiles, mood, and anxiety was obtained upon the first visit in all participants as well as after treatment in RLS patients.
Results
Hepcidin levels exhibited no significant differences between patients with drug-naïve RLS and healthy controls at a diagnosis (7.1 ± 2.4 vs. 7.0 ± 3.2 ng/ml, p = 0.978). Decreased hepcidin levels were significantly associated with decreased RLS severity (β = 0.002, 95% CI = 0.00−0.00, p = 0.005) and improved quality of life (β = 0.002, 95% CI = 0.00−7.01, p = 0.044) in a dose-dependent manner after 12 weeks of treatment with a dopamine agonist. This association was independent of age, sex, inflammatory markers, sleep quality, insomnia, daytime sleepiness, depression, and anxiety.
Conclusion
This study demonstrates a role of hepcidin as a predictor of therapeutic responses in RLS patients.
Support
This work was supported by the Korea Health technology R&D Project through the Korea Health Industry Development Institute, funded by the Ministry of Health & Welfare, South Korea [grant number HI17C2072].