Koji Shibasaki1, Sumito Ogawa2, Shizuru Yamada3, Katsuya Iijima4, Masato Eto5, Koichi Kozaki6, Kenji Toba7, Yasuyoshi Ouchi8, Masahiro Akishita1. 1. Department of Geriatric Medicine, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo, Japan. 2. Department of Geriatric Medicine, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo, Japan. Electronic address: suogawa-tky@umin.ac.jp. 3. Komagane-kogen Ladies Clinic, Komagane City, Nagano, Japan. 4. Institute of Gerontology, The University of Tokyo, Bunkyo-ku, Tokyo, Japan. 5. General Educational Center, The University of Tokyo Hospital, Bunkyo-ku, Tokyo, Japan. 6. Department of Geriatric Medicine, Kyorin University School of Medicine, Mitaka City, Tokyo, Japan. 7. National Center for Geriatrics and Gerontology, Obu City, Aichi, Japan. 8. Federation of National Public Service Personnel Mutual Aid Associations, Toranomon Hospital, Minato-ku, Tokyo, Japan.
Abstract
OBJECTIVES: 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. DESIGN: Prospective cohort study. PARTICIPANTS: Sixty-one subjects aged 75 years or older were recruited after treatment of acute phase illness. MEASUREMENTS: 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. CONCLUSION: 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.
OBJECTIVES: 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. DESIGN: Prospective cohort study. PARTICIPANTS: Sixty-one subjects aged 75 years or older were recruited after treatment of acute phase illness. MEASUREMENTS: 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. CONCLUSION: 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.