title: Physical activity and heart rate variability in older adults: the Cardiovascular Health Study.
abstract: BACKGROUND
  Cardiac mortality and electrophysiological dysfunction both increase with age. Heart rate variability (HRV) provides indices of autonomic function and electrophysiology that are associated with cardiac risk. How habitual physical activity among older adults prospectively relates to HRV, including nonlinear indices of erratic sinus patterns, is not established. We hypothesized that increasing the levels of both total leisure-time activity and walking would be prospectively associated with more favorable time-domain, frequency-domain, and nonlinear HRV measures in older adults.
  
  
  RESULTS
  We evaluated serial longitudinal measures of both physical activity and 24-hour Holter HRV over 5 years among 985 older US adults in the community-based Cardiovascular Health Study. After multivariable adjustment, greater total leisure-time activity, walking distance, and walking pace were each prospectively associated with specific, more favorable HRV indices, including higher 24-hour standard deviation of all normal-to-normal intervals (Ptrend=0.009, 0.02, 0.06, respectively) and ultralow-frequency power (Ptrend=0.02, 0.008, 0.16, respectively). Greater walking pace was also associated with a higher short-term fractal scaling exponent (Ptrend=0.003) and lower Poincaré ratio (Ptrend=0.02), markers of less erratic sinus patterns.
  
  
  CONCLUSIONS
  Greater total leisure-time activity, and walking alone, as well, were prospectively associated with more favorable and specific indices of autonomic function in older adults, including several suggestive of more normal circadian fluctuations and less erratic sinoatrial firing. Our results suggest potential mechanisms that might contribute to lower cardiovascular mortality with habitual physical activity later in life.
authors.affiliation: From the Department of Epidemiology, Harvard School of Public Health, Boston, MA (L.S.-M., J.S., D.M.); Research Centre in Physical Activity, Health and Leisure, Faculty of Sport, University of Porto, Portugal (L.S.-M.); Benjamin Leon Center for Geriatric Research and Education and Department of Medicine, Herbert Wertheim College of Medicine, Florida International University, Miami, FL (P.C.); Department of Epidemiology, University of Washington, Seattle, WA (G.E.D., D.S.S.); Department of Medicine, Cardiovascular Health Research Unit, University of Washington, Seattle, WA (D.S.S.); Heart Rate Variability Laboratory, Cardiovascular Division, Washington University School of Medicine, St Louis, MO (P.K.S.); and Division of Cardiovascular Medicine and Channing Division of Network Medicine, Brigham and Women's Hospital and Harvard Medical School, and Department of Nutrition, Harvard School of Public Health, Boston, MA (D.M.). soaresmiranda@fade.up.pt.
authors.forename: Luisa
authors.initials: L
authors.lastname: Soares-Miranda
authors.affiliation: From the Department of Epidemiology, Harvard School of Public Health, Boston, MA (L.S.-M., J.S., D.M.); Research Centre in Physical Activity, Health and Leisure, Faculty of Sport, University of Porto, Portugal (L.S.-M.); Benjamin Leon Center for Geriatric Research and Education and Department of Medicine, Herbert Wertheim College of Medicine, Florida International University, Miami, FL (P.C.); Department of Epidemiology, University of Washington, Seattle, WA (G.E.D., D.S.S.); Department of Medicine, Cardiovascular Health Research Unit, University of Washington, Seattle, WA (D.S.S.); Heart Rate Variability Laboratory, Cardiovascular Division, Washington University School of Medicine, St Louis, MO (P.K.S.); and Division of Cardiovascular Medicine and Channing Division of Network Medicine, Brigham and Women's Hospital and Harvard Medical School, and Department of Nutrition, Harvard School of Public Health, Boston, MA (D.M.).
authors.forename: Jacob
authors.initials: J
authors.lastname: Sattelmair
authors.affiliation: From the Department of Epidemiology, Harvard School of Public Health, Boston, MA (L.S.-M., J.S., D.M.); Research Centre in Physical Activity, Health and Leisure, Faculty of Sport, University of Porto, Portugal (L.S.-M.); Benjamin Leon Center for Geriatric Research and Education and Department of Medicine, Herbert Wertheim College of Medicine, Florida International University, Miami, FL (P.C.); Department of Epidemiology, University of Washington, Seattle, WA (G.E.D., D.S.S.); Department of Medicine, Cardiovascular Health Research Unit, University of Washington, Seattle, WA (D.S.S.); Heart Rate Variability Laboratory, Cardiovascular Division, Washington University School of Medicine, St Louis, MO (P.K.S.); and Division of Cardiovascular Medicine and Channing Division of Network Medicine, Brigham and Women's Hospital and Harvard Medical School, and Department of Nutrition, Harvard School of Public Health, Boston, MA (D.M.).
authors.forename: Paulo
authors.initials: P
authors.lastname: Chaves
authors.affiliation: From the Department of Epidemiology, Harvard School of Public Health, Boston, MA (L.S.-M., J.S., D.M.); Research Centre in Physical Activity, Health and Leisure, Faculty of Sport, University of Porto, Portugal (L.S.-M.); Benjamin Leon Center for Geriatric Research and Education and Department of Medicine, Herbert Wertheim College of Medicine, Florida International University, Miami, FL (P.C.); Department of Epidemiology, University of Washington, Seattle, WA (G.E.D., D.S.S.); Department of Medicine, Cardiovascular Health Research Unit, University of Washington, Seattle, WA (D.S.S.); Heart Rate Variability Laboratory, Cardiovascular Division, Washington University School of Medicine, St Louis, MO (P.K.S.); and Division of Cardiovascular Medicine and Channing Division of Network Medicine, Brigham and Women's Hospital and Harvard Medical School, and Department of Nutrition, Harvard School of Public Health, Boston, MA (D.M.).
authors.forename: Glen E
authors.initials: GE
authors.lastname: Duncan
authors.affiliation: From the Department of Epidemiology, Harvard School of Public Health, Boston, MA (L.S.-M., J.S., D.M.); Research Centre in Physical Activity, Health and Leisure, Faculty of Sport, University of Porto, Portugal (L.S.-M.); Benjamin Leon Center for Geriatric Research and Education and Department of Medicine, Herbert Wertheim College of Medicine, Florida International University, Miami, FL (P.C.); Department of Epidemiology, University of Washington, Seattle, WA (G.E.D., D.S.S.); Department of Medicine, Cardiovascular Health Research Unit, University of Washington, Seattle, WA (D.S.S.); Heart Rate Variability Laboratory, Cardiovascular Division, Washington University School of Medicine, St Louis, MO (P.K.S.); and Division of Cardiovascular Medicine and Channing Division of Network Medicine, Brigham and Women's Hospital and Harvard Medical School, and Department of Nutrition, Harvard School of Public Health, Boston, MA (D.M.).
authors.forename: David S
authors.initials: DS
authors.lastname: Siscovick
authors.affiliation: From the Department of Epidemiology, Harvard School of Public Health, Boston, MA (L.S.-M., J.S., D.M.); Research Centre in Physical Activity, Health and Leisure, Faculty of Sport, University of Porto, Portugal (L.S.-M.); Benjamin Leon Center for Geriatric Research and Education and Department of Medicine, Herbert Wertheim College of Medicine, Florida International University, Miami, FL (P.C.); Department of Epidemiology, University of Washington, Seattle, WA (G.E.D., D.S.S.); Department of Medicine, Cardiovascular Health Research Unit, University of Washington, Seattle, WA (D.S.S.); Heart Rate Variability Laboratory, Cardiovascular Division, Washington University School of Medicine, St Louis, MO (P.K.S.); and Division of Cardiovascular Medicine and Channing Division of Network Medicine, Brigham and Women's Hospital and Harvard Medical School, and Department of Nutrition, Harvard School of Public Health, Boston, MA (D.M.).
authors.forename: Phyllis K
authors.initials: PK
authors.lastname: Stein
authors.affiliation: From the Department of Epidemiology, Harvard School of Public Health, Boston, MA (L.S.-M., J.S., D.M.); Research Centre in Physical Activity, Health and Leisure, Faculty of Sport, University of Porto, Portugal (L.S.-M.); Benjamin Leon Center for Geriatric Research and Education and Department of Medicine, Herbert Wertheim College of Medicine, Florida International University, Miami, FL (P.C.); Department of Epidemiology, University of Washington, Seattle, WA (G.E.D., D.S.S.); Department of Medicine, Cardiovascular Health Research Unit, University of Washington, Seattle, WA (D.S.S.); Heart Rate Variability Laboratory, Cardiovascular Division, Washington University School of Medicine, St Louis, MO (P.K.S.); and Division of Cardiovascular Medicine and Channing Division of Network Medicine, Brigham and Women's Hospital and Harvard Medical School, and Department of Nutrition, Harvard School of Public Health, Boston, MA (D.M.).
authors.forename: Dariush
authors.initials: D
authors.lastname: Mozaffarian
mesh_terms: D000368:Aged; D002318:Cardiovascular Diseases / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology*; D003430:Cross-Sectional Studies; D015716:Electrocardiography, Ambulatory / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D006304:Health Status; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D007899:Leisure Activities / Q000523:psychology; D008137:Longitudinal Studies; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D011446:Prospective Studies; D016138:Walking / Q000502:physiology* / Q000523:psychology
keywords: electrophysiology; epidemiology; exercise; heart rate; motor activity