INTRODUCTION: Restless legs syndrome (RLS), also known as Willis-Ekbom disease, 
is characterised by abnormal sensations in the legs as well as dysaesthesia. 
Although the aetiology of RLS has not yet been determined, it may be associated 
with systemic inflammation. The neutrophil-to-lymphocyte ratio (NLR) is a new 
and simple marker indicating systemic inflammation. The present study aimed to 
investigate the relationship between systemic inflammation and RLS through the 
use of the NLR.
METHODS: A total of 75 newly diagnosed patients with RLS and 56 healthy control 
subjects were included in the study. Baseline NLR was calculated by dividing the 
absolute neutrophil count by the absolute lymphocyte count. The NLRs of the two 
groups were compared.
RESULTS: There were no significant differences in gender and age between the two 
groups. The NLR was 1.96 ± 0.66 in the patient group and 1.67 ± 0.68 in the 
control group (p = 0.005). Receiver operating characteristic analysis was 
performed to determine the cut-off value of NLR to predict RLS. The NLR was 
predictive at 1.58 with a 64% sensitivity and 50% specificity (95% confidence 
interval 0.55-0.74, area under curve 0.648 ± 0.05). The NLR was found to be 
statistically higher in patients with RLS and may be used to predict RLS.
CONCLUSION: The aetiology of RLS remains undetermined. The present study showed 
that systemic inflammation may play a role in RLS. However, RLS could also be 
associated with systemic inflammatory diseases. This relationship is supported 
by high NLR values, which are related to chronic systemic inflammation.