title: Evaluation of Periodic Limb Movements in Sleep and Iron Status in Children With Autism.
abstract: OBJECTIVE
  Recent data suggest that both disordered sleep and low serum iron occur more frequently in children with autism compared with children with typical development. Iron deficiency has been linked to specific sleep disorders. The goal of the current study was to evaluate periodic limb movements in sleep and iron status in a group of children with autism compared with typically developing children and children with nonautism developmental delay to determine if iron status correlated with polysomnographic measures of latency and continuity and periodic limb movements in sleep.
  
  
  METHODS
  A total of 102 children (68 with autism, 18 typically developing, 16 with developmental delay) aged 2 to 7 years underwent a one-night modified polysomnography study and phlebotomy at the National Institutes of Health to measure serum markers of iron status (ferritin, iron, transferrin, percent transferrin saturation).
  
  
  RESULTS
  No serum iron marker was associated with periodic limb movements of sleep or any other sleep parameter; this did not differ among the diagnostic groups. No significant differences among groups were observed on serum iron markers or most polysomnogram parameters: periodic limb movements in sleep, periodic limb movements index, wake after sleep onset, or sleep efficiency. Children in the autism group had significantly less total sleep time. Serum ferritin was uniformly low across groups.
  
  
  CONCLUSIONS
  This study found no evidence that serum ferritin is associated with polysomnogram measures of latency or sleep continuity or that young children with autism are at increased risk for higher periodic limb movements index compared with typically developing and developmental delay peers.
authors.affiliation: University of Michigan Medical School, Ann Arbor, Michigan; Pediatrics and Developmental Neuroscience Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Lane
authors.affiliation: Pediatrics and Developmental Neuroscience Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland.
authors.forename: Riley
authors.initials: R
authors.lastname: Kessler
authors.affiliation: Pediatrics and Developmental Neuroscience Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland. Electronic address: Shu.Buckley@nih.gov.
authors.forename: Ashura Williams
authors.initials: AW
authors.lastname: Buckley
authors.affiliation: Department of Neurology, New York University, New York, New York.
authors.forename: Alcibiades
authors.initials: A
authors.lastname: Rodriguez
authors.affiliation: Pediatrics and Developmental Neuroscience Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland.
authors.forename: Cristan
authors.initials: C
authors.lastname: Farmer
authors.affiliation: Pediatrics and Developmental Neuroscience Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland.
authors.forename: Audrey
authors.initials: A
authors.lastname: Thurm
authors.affiliation: Pediatrics and Developmental Neuroscience Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland.
authors.forename: Susan
authors.initials: S
authors.lastname: Swedo
authors.affiliation: Department of Pediatrics and Communicable Diseases, University of Michigan, Ann Arbor, Michigan.
authors.forename: Barbara
authors.initials: B
authors.lastname: Felt
mesh_terms: D001321:Autistic Disorder / Q000503:physiopathology*; D002648:Child; D002675:Child, Preschool; D002658:Developmental Disabilities / Q000503:physiopathology; D005293:Ferritins / Q000097:blood*; D006801:Humans; D007501:Iron / Q000378:metabolism; D020189:Nocturnal Myoclonus Syndrome / Q000503:physiopathology*; D017286:Polysomnography; D012890:Sleep / Q000502:physiology*; D013997:Time Factors
chemical_list: D005293:Ferritins; D007501:Iron
keywords: autism; ferritin; iron; periodic limb movements