title: Impact of heart rate variability on C-reactive protein concentrations in Japanese adult nonsmokers: The Toon Health Study.
abstract: OBJECTIVE
  Lower heart rate variability (HRV) is associated with the inflammation that is linked with the progression of atherosclerosis. We examined this association, taking insulin sensitivity into consideration, as it is related to both HRV and inflammation.
  
  
  METHODS
  Subjects were 1728 individuals ages 30-79 years who did not smoke between 2009 and 2012. C-reactive protein (CRP) concentrations and white blood cell (WBC) counts were assessed as markers of inflammation. The homeostasis model assessment index for insulin resistance (HOMA-IR) and Gutt's insulin sensitivity index (ISI) were calculated based on fasting and 2h-post-load glucose and insulin concentrations in a 75-g oral glucose tolerance test. Pulse was recorded for 5 min, and time-domain HRV indices of standard deviation of NN intervals (SDNN) and root mean square of successive differences (RMSSD) were calculated. Power spectral analysis provided frequency domain measures of HRV: high frequency (HF) power, low frequency (LF) power and LF/HF.
  
  
  RESULTS
  Sex and age-adjusted logistic models presented quartiles of SDNN, RMSSD, LF, and HF significantly associated with the highest quartile of CRP or WBC. After adjustment for body mass index and ISI, the associations were attenuated for WBC; however, even after further adjustment for several variables, SDNN, RMSSD, LF, and HF remained significantly associated with elevated CRP concentrations. When results were stratified by weight, the associations appeared more evident among non-overweight individuals.
  
  
  CONCLUSIONS
  Lowered HRV, primarily due to parasympathetic dysfunction, was associated with elevated inflammation, independent of weight, insulin sensitivity, and other related factors.
authors.affiliation: Department of Community Health Systems Nursing, Ehime University Graduate School of Medicine, Toon, Japan. Electronic address: saitoi@m.ehime-u.ac.jp.
authors.forename: Isao
authors.initials: I
authors.lastname: Saito
authors.affiliation: Department of Total Medical Support Center, Ehime University Hospital, Toon, Japan.
authors.forename: Shinich
authors.initials: S
authors.lastname: Hitsumoto
authors.affiliation: Department of Public Health, Juntendo University Graduate School of Medicine, Tokyo, Japan.
authors.forename: Koutatsu
authors.initials: K
authors.lastname: Maruyama
authors.affiliation: Department of Public Health, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan.
authors.forename: Eri
authors.initials: E
authors.lastname: Eguchi
authors.affiliation: Center for Education and Educational Research, Faculty of Education, Ehime University, Matsuyama, Japan.
authors.forename: Tadahiro
authors.initials: T
authors.lastname: Kato
authors.affiliation: Department of Clinical Laboratory, Ehime University Hospital, Toon, Japan.
authors.forename: Ai
authors.initials: A
authors.lastname: Okamoto
authors.affiliation: Department of Diabetes and Molecular Genetics, Ehime University Graduate School of Medicine, Toon, Japan.
authors.forename: Ryoichi
authors.initials: R
authors.lastname: Kawamura
authors.affiliation: Department of Diabetes and Molecular Genetics, Ehime University Graduate School of Medicine, Toon, Japan.
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Takata
authors.affiliation: Department of Diabetes and Molecular Genetics, Ehime University Graduate School of Medicine, Toon, Japan.
authors.forename: Wataru
authors.initials: W
authors.lastname: Nishida
authors.affiliation: Department of Clinical Laboratory, Ehime University Hospital, Toon, Japan.
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Nishimiya
authors.affiliation: Department of Diabetes and Molecular Genetics, Ehime University Graduate School of Medicine, Toon, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Onuma
authors.affiliation: Department of Diabetes and Molecular Genetics, Ehime University Graduate School of Medicine, Toon, Japan.
authors.forename: Haruhiko
authors.initials: H
authors.lastname: Osawa
authors.affiliation: Department of Public Health, Juntendo University Graduate School of Medicine, Tokyo, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Tanigawa
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D050197:Atherosclerosis / Q000097:blood / Q000453:epidemiology / Q000503:physiopathology*; D001786:Blood Glucose; D002097:C-Reactive Protein / Q000378:metabolism*; D002940:Circadian Rhythm / Q000502:physiology*; D003430:Cross-Sectional Studies; D018450:Disease Progression; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006306:Health Surveys; D006339:Heart Rate; D006801:Humans; D007249:Inflammation / Q000097:blood* / Q000150:complications / Q000503:physiopathology; D007333:Insulin Resistance / Q000502:physiology; D007564:Japan / Q000453:epidemiology; D007958:Leukocyte Count; D008297:Male; D008875:Middle Aged; D009017:Morbidity / Q000639:trends; D012189:Retrospective Studies; D012307:Risk Factors; D017678:Sex Distribution
chemical_list: D001786:Blood Glucose; D002097:C-Reactive Protein
keywords: Epidemiology; Heart rate variability; Inflammation; Insulin sensitivity