title: Effect of levothyroxine on prolonged nocturnal sleep time and excessive daytime somnolence in patients with idiopathic hypersomnia.
abstract: OBJECTIVE
  This study aims to examine the effect of levothyroxine, a thyroid hormone, on a prolonged nocturnal sleep and excessive daytime somnolence (EDS) in patients with idiopathic hypersomnia.
  
  
  METHODS
  In a prospective, open-label study, nine patients were enrolled. All subjects met criteria for idiopathic hypersomnia with long sleep time defined by the International Classification of Sleep Disorders, 2nd edition (ICSD-2). Subjects with sleep apnea syndrome, obesity or hypothyroidism were excluded. Sleep architecture and subjective daytime somnolence were estimated by polysomnography (PSG) and Epworth Sleepiness Scale (ESS), respectively. After baseline examinations, levothyroxine (25μg/day) was orally administered every day. Mean total sleep time, ESS score at baseline were compared with those after treatment (2, 4 and 8 weeks).
  
  
  RESULTS
  Mean age of participants was 23.8±13.7 years old. At baseline, mean total sleep time (hours) and ESS score were 12.9±0.3 and 17.8±1.4, respectively. Mean total sleep times after treatment were 9.1±0.7 and 8.5±1.0h at 4 and 8 treatment weeks, respectively. Mean ESS scores were 8.8±2.3 and 7.4±2.8 at 4 and 8 treatment weeks, respectively. One patient dropped out at the 2nd week due to poor effect. No adverse effects were noted.
  
  
  CONCLUSIONS
  After treatment with levothyroxine for over 4 weeks, prolonged sleep time and EDS were improved. Levothyroxine was effective for hypersomnia and well tolerated.
authors.affiliation: Department of Neuropsychiatry, Kagawa University School of Medicine, Miki, Kita, Kagawa, Japan. shinnoh@med.kagawa-u.ac.jp
authors.forename: Hideto
authors.initials: H
authors.lastname: Shinno
authors.forename: Ichiro
authors.initials: I
authors.lastname: Ishikawa
authors.forename: Mami
authors.initials: M
authors.lastname: Yamanaka
authors.forename: Ai
authors.initials: A
authors.lastname: Usui
authors.forename: Sonoko
authors.initials: S
authors.lastname: Danjo
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Inami
authors.forename: Jun
authors.initials: J
authors.lastname: Horiguchi
authors.forename: Yu
authors.initials: Y
authors.lastname: Nakamura
mesh_terms: D000284:Administration, Oral; D000293:Adolescent; D000328:Adult; D005260:Female; D006801:Humans; D020177:Idiopathic Hypersomnia / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D017286:Polysomnography; D011446:Prospective Studies; D012890:Sleep / Q000187:drug effects*; D012894:Sleep Stages / Q000187:drug effects*; D013974:Thyroxine / Q000008:administration & dosage* / Q000009:adverse effects; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D013974:Thyroxine