title: Heart rate variability during sleep in Down's syndrome.
abstract: We observed heart rate (HR) variability in the sleep-wake cycle of young adults with Down's syndrome (DS) and their age-matched normal controls. Spontaneous HR fluctuations for 10 min during each sleep stage were analyzed by spectral analysis. Only during rapid eye movement (REM) sleep, a middle-frequency (0.05-0.15 cycles/beat) component of the HR fluctuations jointly mediated by the sympathetic and parasympathetic nerves, was significantly lower in the DS than in the control subjects. As the high-frequency (0.15-0.40 cycles/beat) component mediated by the parasympathetic nerve was not different in the two groups, it is suggested that the sympathetic activity during REM sleep is lower in DS than in controls.
authors.affiliation: Department of Physiology, School of Medicine, University of Tokushima, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Sei
authors.forename: T
authors.initials: T
authors.lastname: Enai
authors.forename: H Y
authors.initials: HY
authors.lastname: Chang
authors.forename: Y
authors.initials: Y
authors.lastname: Morita
mesh_terms: D000328:Adult; D004314:Down Syndrome / Q000503:physiopathology*; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D012890:Sleep / Q000502:physiology*; D012895:Sleep, REM / Q000502:physiology