title: Favorable effect of sympathetic nervous activity on rehabilitation outcomes in frail elderly.
abstract: OBJECTIVE
  Previous studies have suggested the relationship between physical function, mortality, and autonomic nervous activity in frail elderly and that maintaining sympathetic nervous activity might lead to improved physical function and mortality in the elderly population. The aim of this study was to investigate the utility of sympathetic nervous activity measured by heart rate variability in frail elderly patients undergoing inpatient rehabilitation, further focusing the nervous activity on the effect of rehabilitation therapy.
  
  
  METHODS
  Prospective cohort study.
  
  
  METHODS
  Sixty-one subjects aged 75 years or older were recruited after treatment of acute phase illness.
  
  
  METHODS
  Before undergoing rehabilitation, data of 24-hour Holter monitoring and a blood venous sample were obtained. From RR intervals in the electrocardiogram, heart rate and SDs of all NN intervals in all 5-minute segments of the entire recording, power spectral density, low frequency (LF), high frequency (HF), and low frequency/high frequency (LF/HF) were calculated. Functional Independence Measure (FIM) and Barthel index were used to measure physical function.
  
  
  RESULTS
  FIM score and Barthel index were 46.8 ± 25.4 and 32.8 ± 31.7, respectively. Serum total protein, albumin, hemoglobin, and total cholesterol were all significantly related to FIM score and Barthel index before rehabilitation. Heart rate variability indices did not show a significant relationship with physical function, whereas the high LH/HF group showed significant improvement in physical function compared with the low LH/HF group. Moreover, LF/HF frequency was a predictive factor for improvement of physical function after 2 months of rehabilitation.
  
  
  CONCLUSIONS
  A favorable effect of preserved LF/HF on rehabilitation outcome was observed in elderly undergoing rehabilitation. Preservation of sympathetic nervous activity may lead to improved physical function in the elderly.
authors.affiliation: Department of Geriatric Medicine, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Shibasaki
authors.affiliation: Department of Geriatric Medicine, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo, Japan. Electronic address: suogawa-tky@umin.ac.jp.
authors.forename: Sumito
authors.initials: S
authors.lastname: Ogawa
authors.affiliation: Komagane-kogen Ladies Clinic, Komagane City, Nagano, Japan.
authors.forename: Shizuru
authors.initials: S
authors.lastname: Yamada
authors.affiliation: Institute of Gerontology, The University of Tokyo, Bunkyo-ku, Tokyo, Japan.
authors.forename: Katsuya
authors.initials: K
authors.lastname: Iijima
authors.affiliation: General Educational Center, The University of Tokyo Hospital, Bunkyo-ku, Tokyo, Japan.
authors.forename: Masato
authors.initials: M
authors.lastname: Eto
authors.affiliation: Department of Geriatric Medicine, Kyorin University School of Medicine, Mitaka City, Tokyo, Japan.
authors.forename: Koichi
authors.initials: K
authors.lastname: Kozaki
authors.affiliation: National Center for Geriatrics and Gerontology, Obu City, Aichi, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Toba
authors.affiliation: Federation of National Public Service Personnel Mutual Aid Associations, Toranomon Hospital, Minato-ku, Tokyo, Japan.
authors.forename: Yasuyoshi
authors.initials: Y
authors.lastname: Ouchi
authors.affiliation: Department of Geriatric Medicine, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Akishita
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000032:analysis; D002561:Cerebrovascular Disorders / Q000503:physiopathology* / Q000534:rehabilitation*; D015716:Electrocardiography, Ambulatory; D005260:Female; D050723:Fractures, Bone / Q000503:physiopathology* / Q000534:rehabilitation*; D016330:Frail Elderly; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D007564:Japan; D008297:Male; D011446:Prospective Studies; D013564:Sympathetic Nervous System / Q000503:physiopathology*; D016896:Treatment Outcome
chemical_list: D015415:Biomarkers
keywords: Frailty; Functional Independence Measure; Holter monitoring; rehabilitation