title: EEG power spectra response to a 4-h phase advance and gaboxadol treatment in 822 men and women.
abstract: OBJECTIVE
  To explore the effect of gaboxadol on NREM EEG in transient insomnia using power spectral analysis and evaluate the response between men and women.
  
  
  METHODS
  This was a randomized, double-blind, 3-way, parallel-group transient insomnia study in 22 sleep laboratories. After a baseline night (N1), subjects underwent a 4-h phase-advance of their habitual sleep time the following night (N2). Healthy subjects aged 18-64 y were given single-blind placebo on N1 followed by double-blind treatment on N2 (gaboxadol 10 mg [n = 271], 15 mg [n = 274], or placebo [n = 277])
  
  
  RESULTS
  At baseline, women showed significantly greater values in low frequency activity (< 10 Hz) and in high spindle/low beta frequency activity (14-18 Hz) compared to men. During the phase advance (placebo N2-baseline N1), there was a significant increase in power within the high spindle/low beta frequency range (15-17 Hz) and a significant reduction in beta activity (20-32 Hz), which was greater in women than men. Gaboxadol induced a significant (dose-related) increase in low frequencies (< 8 Hz) and a significant (dose-related) decrease within the alpha/spindle range (11-12 Hz). The effect was dependent upon sex, with a greater magnitude of effect observed in women than men.
  
  
  CONCLUSIONS
  Gaboxadol shows a characteristic NREM EEG spectral profile in a model of transient insomnia. Men and women show clear differences in NREM EEG activity at baseline, to gaboxadol treatment and to phase-shifts in habitual sleep/wake times. The exact mechanisms underlying the sex differences remain unclear, but sex is an important variable in studies evaluating sleep and gaboxadol. TRIAL REGISTRY INFORMATION:
  
  
  BACKGROUND
  www.clinicaltrials.gov, study identifier: NCT00102167.
authors: Merck Research Laboratories, Biometrics Research, Rahway, NJ, USA.
authors: Junshui
authors: J
authors: Ma
authors: Derk-Jan
authors: DJ
authors: Dijk
authors: Vladimir
authors: V
authors: Svetnik
authors: Yevgen
authors: Y
authors: Tymofyeyev
authors: Shubhankar
authors: S
authors: Ray
authors: James K
authors: JK
authors: Walsh
authors: Steve
authors: S
authors: Deacon
mesh_terms: D000293:Adolescent; D000328:Adult; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004569:Electroencephalography / Q000187:drug effects* / Q000379:methods* / Q000706:statistics & numerical data; D005260:Female; D018755:GABA Agonists / Q000627:therapeutic use*; D006801:Humans; D007555:Isoxazoles / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D017678:Sex Distribution; D007319:Sleep Initiation and Maintenance Disorders / Q000188:drug therapy*; D013997:Time Factors; D055815:Young Adult
chemical_list: D018755:GABA Agonists; D007555:Isoxazoles; C015542:gaboxadol