title: Association of Restless Legs Syndrome With Incident Parkinson's Disease.
abstract: The association between restless legs syndrome (RLS) and Parkinson's disease (PD) has been extensively studied with inconclusive results; therefore, we prospectively examined the associations of the presence of RLS with development of incident PD.
  
  
  
  From a nationally representative prospective cohort of almost 3.5 million US veterans (age: 60 ± 14 years, 93% male, median follow-up time of 7.8 years [interquartile range: 6.4-8.4 years]), we created a propensity-matched cohort of 100882 PD-free patients and examined the association between prevalent RLS and incident PD. This association was also assessed in the entire cohort. Associations were examined using Cox models.
  
  
  
  There were 68 incident PD events (0.13%, incidence rate 1.87 [1.48-2.37]/10000 patient-years) in the RLS-negative group, and 185 incident PD events (0.37%, incidence rate 4.72 [4.09-5.45]/10000 patient-years) in the RLS-positive group in the propensity-matched cohort. Prevalent RLS was associated with more than twofold higher risk of incident PD (hazard ratio [HR]: 2.57, 95% confidence interval [CI]: 1.95-3.39) compared to RLS-negative patients. Qualitatively similar results were found when we examined the entire 3.5 million cohort: Prevalent RLS was associated with more than twofold higher risk of incident PD (multivariable adjusted HR: 2.81, 95%CI: 2.41-3.27).
  
  
  
  RLS and PD share common risk factors. In this large cohort of US veterans, we found that prevalent RLS is associated with higher risk of incident PD during 8 years of follow-up, suggesting that RLS could be an early clinical feature of incident PD.
authors.affiliation: Department of Neurology, Sibiu County Emergency Hospital, Sibiu, Romania.|2nd Department of Neurology, Targu Mures Emergency Clinical County Hospital, Targu Mures, Romania.|Szentágothai Doctoral School, Semmelweis University, Budapest, Hungary.
authors.forename: Szabolcs
authors.initials: S
authors.lastname: Szatmari
authors.affiliation: Szentágothai Doctoral School, Semmelweis University, Budapest, Hungary.|Department of Neurology, Semmelweis University, Budapest, Hungary.
authors.forename: Daniel
authors.initials: D
authors.lastname: Bereczki
authors.affiliation: Department of Neurology, Semmelweis University, Budapest, Hungary.
authors.forename: Katalin
authors.initials: K
authors.lastname: Fornadi
authors.affiliation: Division of Nephrology, University of California, Irvine, CA.
authors.forename: Kamyar
authors.initials: K
authors.lastname: Kalantar-Zadeh
authors.affiliation: Division of Nephrology, Department of Medicine, University of Tennessee Health Science Center, Memphis, TN.|Nephrology Section, Memphis Veterans Affairs Medical Center, Memphis, TN.
authors.forename: Csaba P
authors.initials: CP
authors.lastname: Kovesdy
authors.affiliation: Division of Nephrology, Department of Medicine, University of Tennessee Health Science Center, Memphis, TN.|Department of Transplantation and Surgery, Semmelweis University, Budapest, Hungary.
authors.forename: Miklos Z
authors.initials: MZ
authors.lastname: Molnar
mesh_terms: D000368:Aged; D015897:Comorbidity; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000453:epidemiology*; D015995:Prevalence; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012148:Restless Legs Syndrome / Q000453:epidemiology*; D012307:Risk Factors; D014728:Veterans / Q000706:statistics & numerical data
keywords: Parkinson’s disease.; restless legs syndrome