Overview

• In a retrospective study of Korean NHIS data from 2002 to 2019, researchers compared 9,919 patients with restless leg syndrome to 9,919 matched controls.
• Parkinson's incidence reached 1.6% in the RLS group versus 1.0% in controls over long-term follow-up, with a shorter time to diagnosis among those with RLS.
• RLS patients recorded as receiving dopamine agonists such as pramipexole or ropinirole showed 0.5% Parkinson's incidence compared with 2.1% in untreated RLS.
• Authors emphasized that observational data cannot prove that dopamine agonists prevent or delay Parkinson's and suggested possibilities like diagnostic masking or confounding.
• The findings moderate earlier reports of stronger associations, including a large U.S. veterans analysis, and highlight the need for prospective and mechanistic studies.