title: Age-related changes in cardiac autonomic control during sleep.
abstract: Aging is commonly associated with decreased sleep quality and increased periodic breathing (PB) that can influence heart rate variability (HRV). Cardiac autonomic control, as inferred from HRV analysis, was determined, taking into account the sleep quality and breathing patterns. Two groups of 12 young (21.1 +/- 0.8 years) and 12 older (64.9 +/- 1.9 years) volunteers underwent electroencephalographic, cardiac, and respiratory recordings during one experimental night. Time and frequency domain indices of HRV were calculated in 5-min segments, together with electroencephalographic and respiratory power spectra. In the elderly, large R-R oscillations in the very-low frequency (VLF) range emerged, that reflected the frequency of PB observed in 18% of the sleep time. PB occurred more frequently during rapid eye movement sleep (REM) sleep and caused a significant (P < 0.02) increase in the standard deviation of normal R-R intervals (SDNN) and absolute low-frequency (LF) power. With normal respiratory patterns, SDNN, absolute VLF, LF, and high frequency (HF) power fell during each sleep stage (P < 0.01) compared with young subjects, with no significant sleep-stage dependent variations. An overall decrease (P < 0.01) in normalized HF/(LF + HF) was observed in the elderly, suggesting a predominant loss of parasympathetic activity which may be related to decreased slow-wave sleep duration. These results indicate that two distinct breathing features, implying different levels of autonomic drive to the heart, influence HRV in the elderly during sleep. The breathing pattern must be considered to correctly interpret HRV in the elderly.
authors.affiliation: Laboratoire des Régulations Physiologiques et des Rythmes Biologiques chez l'Homme, Strasbourg, Cedex, France. brandenberger.gabrielle@medecine.u-strasbg.fr
authors.forename: Gabrielle
authors.initials: G
authors.lastname: Brandenberger
authors.forename: Antoine U
authors.initials: AU
authors.lastname: Viola
authors.forename: Jean
authors.initials: J
authors.lastname: Ehrhart
authors.forename: Anne
authors.initials: A
authors.lastname: Charloux
authors.forename: Bernard
authors.initials: B
authors.lastname: Geny
authors.forename: François
authors.initials: F
authors.lastname: Piquard
authors.forename: Chantal
authors.initials: C
authors.lastname: Simon
mesh_terms: D000328:Adult; D000367:Age Factors; D000375:Aging / Q000502:physiology*; D001341:Autonomic Nervous System / Q000502:physiology*; D015992:Body Mass Index; D002680:Chin; D004562:Electrocardiography; D004569:Electroencephalography; D004576:Electromyography; D004585:Electrooculography; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010507:Periodicity; D012119:Respiration; D012894:Sleep Stages / Q000502:physiology; D012895:Sleep, REM / Q000502:physiology*; D013997:Time Factors