title: Heart rate variability and cardiorespiratory coupling in obstructive sleep apnea: elderly compared with young.
abstract: BACKGROUND
  Aging is known to be a major contributing factor to the increased risk of obstructive sleep apnea (OSA). With aging, breathing undergoes significant changes during sleep, increasing the prevalence of apnea events, which affects heart rate variability (HRV) and cardiorespiratory coupling (CRC).
  
  
  OBJECTIVE
  To compare HRV and CRC during wakefulness and sleep between young and elderly patients with and without OSA; and to determine whether the presence of OSA in young and elderly patients has a different impact on HRV and CRC during sleep.
  
  
  METHODS
  One hundred subjects, 50 young (mean age, 27 ± 9; 20 normal and 30 OSA) and 50 elderly (mean age, 65 ± 7; 20 normal and 30 OSA), underwent polysomnography. Spectral, cross-spectrum, and HRV parameters were analyzed during wakefulness and sleep.
  
  
  RESULTS
  The spectral analysis indicated that age affected HRV, with higher values of low frequency (P < 0.05) in elderly subjects during wakefulness and an interaction between the presence of OSA and age. OSA influenced HRV during sleep with lower LF/HF ratios during stage 2 (S2) and rapid eye movement (REM) sleep (P <0.05), with an interaction between the presence of OSA and age in REM sleep. Elderly patients had significantly lower percent tachogram power coherent with respiration (%TPCR) during wakefulness (P < 0.05), and OSA led to lower %TPCR during S2.
  
  
  CONCLUSIONS
  Age and OSA have an unfavorable impact on HRV, with reduced autonomic modulation during wakefulness, S2, and REM sleep. Age affects CRC during wakefulness and the presence of OSA affects CRC during sleep.
authors.affiliation: Cardiopulmonary Physiotherapy Laboratory, Physiotherapy Department, Federal University of São Carlos (UFSCar), Rodovia Washington Luís, São Carlos, Brazil. Electronic address: retrimer@hotmail.com.
authors.forename: R
authors.initials: R
authors.lastname: Trimer
authors.affiliation: Politecnico di Milano, Division Dipartimento di Elettronica, Informazione e Bioingegneria, Milan, Italy.
authors.forename: R
authors.initials: R
authors.lastname: Cabidu
authors.affiliation: Nove de Julho University, São Paulo, Brazil.
authors.forename: L L M
authors.initials: LL
authors.lastname: Sampaio
authors.affiliation: University at Santa Casa de Misericórdia of São Paulo, São Paulo, Brazil.
authors.forename: R
authors.initials: R
authors.lastname: Stirbulov
authors.affiliation: Sleep Medicine and Biology Discipline, Psychobiology Department, Federal University of São Paulo, São Paulo, Brazil.
authors.forename: D
authors.initials: D
authors.lastname: Poiares
authors.affiliation: Department of Human Motion Sciences, Physical Therapy School, Federal University of São Paulo, São Paulo, Brazil.
authors.forename: S
authors.initials: S
authors.lastname: Guizilini
authors.affiliation: Politecnico di Milano, Division Dipartimento di Elettronica, Informazione e Bioingegneria, Milan, Italy.
authors.forename: A M
authors.initials: AM
authors.lastname: Bianchi
authors.affiliation: Sleep Institute of São Carlos, São Carlos, Brazil.
authors.forename: F S M
authors.initials: FS
authors.lastname: Costa
authors.affiliation: Cardiopulmonary Physiotherapy Laboratory, Physiotherapy Department, Federal University of São Carlos (UFSCar), Rodovia Washington Luís, São Carlos, Brazil.
authors.forename: R G
authors.initials: RG
authors.lastname: Mendes
authors.affiliation: Sleep Institute of São Carlos, São Carlos, Brazil.
authors.forename: A
authors.initials: A
authors.lastname: Delfino
authors.affiliation: Department of Physical Therapy and Integrative Physiology Laboratory, College of Applied Health Sciences, University of Illinois - Chicago, Chicago, IL, USA.
authors.forename: R
authors.initials: R
authors.lastname: Arena
authors.affiliation: Cardiopulmonary Physiotherapy Laboratory, Physiotherapy Department, Federal University of São Carlos (UFSCar), Rodovia Washington Luís, São Carlos, Brazil.
authors.forename: A
authors.initials: A
authors.lastname: Borghi-Silva
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D003430:Cross-Sectional Studies; D006321:Heart / Q000503:physiopathology*; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D012119:Respiration; D012890:Sleep / Q000502:physiology; D020181:Sleep Apnea, Obstructive / Q000503:physiopathology*; D014851:Wakefulness / Q000502:physiology
keywords: Age; Cardiorespiratory coupling; Elderly; Heart rate variability; Obstructive sleep apnea; Young