Restless legs syndrome is a relevant comorbidity in patients with inflammatory bowel disease

Background and aims: In patients with inflammatory bowel disease (IBD), restless legs syndrome (RLS) may occur as an extraintestinal disease manifestation. Iron deficiency (ID) or folate deficiency/vitamin B₁₂ deficiency (FD/VB₁₂D) has previously been described to cause RLS. Here, we determined the prevalence and severity of RLS in IBD patients and evaluated the effect of iron and/or folic acid/vitamin B₁₂ supplementation. Methods: Patients were screened for ID and RLS by a gastroenterologist. If RLS was suspected, a neurologist was consulted for definitive diagnosis and severity. Patients with RLS and ID, FD, or VB₁₂D received supplementation and were followed-up at weeks 4 and 11 after starting supplementation. Results: A total of 353 IBD patients were included. Prevalence for RLS was 9.4% in Crohn’s disease (CD) and 8% in ulcerative colitis (UC). Prevalence for the subgroup of clinically relevant RLS (symptoms ≥ twice/week with at least moderate distress) was 7.1% (n = 16) for CD and 4.8% (n = 6) for UC. 38.7% of RLS patients presented with ID, FD, and/or VB₁₂D. Most frequently ID was seen (25.8%; n = 8). Iron supplementation resulted in RLS improvement (p = 0.029) at week 4 in seven out of eight patients. Conclusion: Although the overall prevalence of RLS in IBD did not differ to the general population, clinically relevant RLS was more frequent in IBD patients and, therefore, it is important for clinicians to be aware of RLS symptoms. Though for definite diagnosis and proper treatment of RLS, a neurologist must be consulted. Additionally, iron supplementation of IBD patients with ID can improve RLS symptoms. Trial registration: ClinicalTrials.gov No. NCT03457571.