title: Body mass index is related to autonomic nervous system activity as measured by heart rate variability--a replication using short term measurements.
abstract: OBJECTIVE
  The present analysis is a replication of previous findings presenting first evidence of an association between body mass index (BMI) and autonomic nervous system (ANS) activity as measured by heart rate variability (HRV), in healthy non-obese adults.
  
  
  METHODS
  A total of fifty-nine apparently healthy male (M) and female (F) individuals (M/F = 15/44) were included in the trial. HRV data for analysis was derived from 5 minutes of baseline recordings, while the subject was sitting on a comfortable chair. Subjects' body measures (weight and height) were taken and BMI was obtained according to common calculation (kg/m²).
  
  
  RESULTS
  BMI was inversely related to pNN50 and RMSSD components of HRV. Statistically significant differences between stratified groups (BMI<20, BMI 20-25, BMI >25) only occurred for analysis of pNN50 components. The pNN50 components and RMSSD are strongly associated with cardiac vagal influence, and thus represents parasympathetic activity.
  
  
  CONCLUSIONS
  The present data supports previous findings, that sympatho-vagal balance is related to BMI in non-obese, healthy individuals, providing evidence for a prominent role of the vagus nerve in the modulation of the energy expenditure of the human organism. Furthermore, this relation can be observed in short term recordings of HRV of 5 minutes in length.
authors.affiliation: Julian Koenig, SRH University Heidelberg, Maaβstraβe 26, 69123 Heidelberg, julian.koenig@fh-heidelberg.de, Tel. +049 151 58748926, Fax. +049 6221 884152.
authors.forename: J
authors.initials: J
authors.lastname: Koenig
authors.forename: M N
authors.initials: MN
authors.lastname: Jarczok
authors.forename: M
authors.initials: M
authors.lastname: Warth
authors.forename: R J
authors.initials: RJ
authors.lastname: Ellis
authors.forename: C
authors.initials: C
authors.lastname: Bach
authors.forename: T K
authors.initials: TK
authors.lastname: Hillecke
authors.forename: J F
authors.initials: JF
authors.lastname: Thayer
mesh_terms: D000328:Adult; D001341:Autonomic Nervous System / Q000502:physiology*; D001827:Body Height; D015992:Body Mass Index; D001835:Body Weight; D004734:Energy Metabolism; D005260:Female; D064368:Healthy Volunteers; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D015203:Reproducibility of Results; D013997:Time Factors; D014630:Vagus Nerve / Q000502:physiology; D055815:Young Adult